Anas Final Internship Report.pdf

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September 11, 2014

INTERNSHIPREPORT

IBRAHIM FIBRES

LIMITED38KM, Faisalabad Sheikhupura Road,

Faisalabad



INTERNSHIP REPORT | IFL | 2014

1

SUBMITTED TO

Mr. Raza Ali Alvi

(Manager Training & Development)

SUBMITTED BY

Anas Bin AshrafBS Chemical Engineering, Third Year

National University of Sciences and Technology

(NUST), Islamabad

Zaid Ashraf RanaBS Chemical Engineering, Graduate


(NUST), Islamabad

Imran RasheedBS Chemical Engineering, Final Year

University of The Punjab (PU), Lahore

Amina MehmoodBS Chemical Engineering, Final Year


(NUST), Islamabad

Aqsa KhalidBS Polymer Engineering, Final Year

University of Engineering and Technology

(UET), Lahore




2

“ In The Name of Allah; The Most Beneficent, and The Most Merciful ”




3

“ Knock, And He'll open the door

Vanish, And He'll make you shine like the sun

Fall, And He'll raise you to the heavens

Become nothing, And He'll turn you into everything.”

( Rumi )




4

Table of ContentsAcknoledgments………………………………………………………………………………………10

Preface…….................................................................................................................... ............11

Safety Precautions…..……………………………………… ..……………………………………….12

Company Profile……………………………………………………………………………………….13

Polymer Section………………………………………………………………………………………..17

Product (PET) Introduction......................................................................................................... 18

Process Summary for PET Production ....................................................................................... 18

Mass Balance for PET Process ................................................................................................... 20

What is PTA? ................................................................................................................................ 21

PTA Uses ....................................................................................................................................... 22

PTA Section Division .................................................................................................................... 22

Storage and Handling ............................................................................................................. 22

Charging of PTA ........................................................................................................................ 23

Conveying of PTA ..................................................................................................................... 23

Process Flow Diagram ................................................................................................................ 25

Main Equipment Used ................................................................................................................ 25

Filter .................................................................................................................................. 25

Compressor ................................................................................................................... 26

Cooler ............................................................................................................................. 26

Rotary Feeder ............................................................................................................... 26

Equipment Interlocks .................................................................................................................. 27

Ethylene Glycol ........................................................................................................................... 27

Process Description .................................................................................................................... 27

MEG Sampling............................................................................................................................. 28

MEG Unloading and pumping to Process line ....................................................................... 28

MEG Uses ..................................................................................................................................... 29

Process Flow Diagram ................................................................................................................ 29Equipment Interlocks .................................................................................................................. 30

EGR……………………………………………………………………………………………………….29



Kettle type Evaporator ............................................................................................... 31




5

Distillation Column ....................................................................................................... 32



HTM……………………………………………………………………………………………………….33


BCO Cycle ................................................................................................................................... 36

HTM Cycle .................................................................................................................................... 36



Furnace .......................................................................................................................... 37

Conduction ...................................................................................................... 38

Convection ...................................................................................................... 38

Radiation ........................................................................................................... 38

Stack ................................................................................................................................ 38

Pre-Heater (HFO).......................................................................................................... 38

Atomizer ......................................................................................................................... 38

Blower .............................................................................................................................. 39

Economizer .................................................................................................................... 39

Damper .......................................................................................................................... 39


TDO……………………………………………………………………………………………………….40



TDO Uses ...................................................................................................................................... 42

Catalyst Systems……………………………………………………………………………………….42



Paste Preparation……………………………………………………………………………………..44




Shank System ................................................................................................................ 46

Paste Mixer ..................................................................................................................... 46




6

Esterfication……………………………………………………………………………………………..46


Temperature and Pressure ........................................................................................................ 47

Residence Time ........................................................................................................................... 47

Acid Number ............................................................................................................................... 47


ES-1 ................................................................................................................................... 48

ES-2 ................................................................................................................................... 49

Polycondensation……………………………………………………………………………………..50



PP-1 and PP-2 ................................................................................................................ 52

DRR ................................................................................................................................... 52


Scrapper Condenser .................................................................................................. 53

Ejector System ............................................................................................................... 53

Vacuum Pump ............................................................................................................. 53

Fume Arrestor ................................................................................................................ 53

MEG Safety .................................................................................................................................. 54

Emergency Overview ................................................................................................. 54

Inhalation ....................................................................................................................... 54

Ingestion ......................................................................................................................... 54

Skin Contact .................................................................................................................. 54

Eye Contact .................................................................................................................. 54

Chronic Exposure ......................................................................................................... 54

Aggravation of Pre-existing Conditions ................................................................. 54

First Aid Measures ......................................................................................................... 55

Inhalation ....................................................................................................................... 55

Ingestion ......................................................................................................................... 55

Skin Contact .................................................................................................................. 55

Eye Contact .................................................................................................................. 55

Note to Physician ......................................................................................................... 55




7

PTA Safety .................................................................................................................................... 55

Emergency Overview ................................................................................................. 55

Skin contact .................................................................................................................. 55

Inhalation ....................................................................................................................... 55

Ingestion ......................................................................................................................... 55

Eye contact ................................................................................................................... 56


Eye ................................................................................................................................... 56

Skin ................................................................................................................................... 56

Inhalation ....................................................................................................................... 56

Ingestion ......................................................................................................................... 56

PET Safety ..................................................................................................................................... 56Emergency Overview ................................................................................................. 56

Inhalation ....................................................................................................................... 56

Skin ................................................................................................................................... 56

Absorption ..................................................................................................................... 56

Ingestion ......................................................................................................................... 57

Eyes .................................................................................................................................. 57

Target Organs ............................................................................................................... 57

Primary Routes of Entry (Exposure) .......................................................................... 57


Inhalation ....................................................................................................................... 57

Skin ................................................................................................................................... 57

Ingestion ......................................................................................................................... 57

Eyes .................................................................................................................................. 57

Utilities……………………………………………………………………………………………………58

Boiler.…………………………………………………………………………………………………….58

Types ............................................................................................................................................. 58

Components ............................................................................................................................... 59



Capacities ................................................................................................................................... 62




8


Why Nitrogen is Important? ....................................................................................................... 63

Production ..................................................................................................................... 63


Technical Nitrogen ...................................................................................................... 64

Pure Nitrogen ................................................................................................................ 64

Pressure Swing Adsorption ......................................................................................... 64


Applications ................................................................................................................................ 67

Cooling Towers…………………………………………………………………………………………68

Basics ............................................................................................................................................ 68


Process Diagram ......................................................................................................................... 70

Water Treatment Plant………………………………………………………………………………..71

Water required: ........................................................................................................................... 71

Equipments .................................................................................................................................. 72



Chillers……………………………………………………………………………………………………75

Electric Chiller .............................................................................................................................. 75Process Description .................................................................................................................... 77

Compressor Drive...................................................................................................................... 77

Compressor ................................................................................................................................ 77

Condenser .................................................................................................................................. 77

Evaporator .................................................................................................................................. 77


Steam Absorption Chiller ........................................................................................................... 78


High Temperature Generator (HTG) .................................................................................... 79

Low Temperature Generator (LTG) ..................................................................................... 79

Condenser .................................................................................................................................. 79

Evaporator .................................................................................................................................. 80

Absorber ...................................................................................................................................... 80






10

UDY/SPUN TOW ................................................................................................... 97

PSF ......................................................................................................................... 99




11

ACKNOWLEDGMENTS

We are thankful to, Almighty Allah for His unlimited blessings and

bounties; for keeping us sane, sound and successful, our Parents for

all their support and trust in us, Ibrahim Fibres Limited for providing

us with this great opportunity which not only give exposure to

industry but also enhanced our technical and professional skills.

Our Instructors Mr. Muhammad Saeed (Area Manager Polymer), Mr.

Haseeb (Deputy Manager Polymer), Mr. Mirza Faqeer (Area

Manager Utilities), Mr. Nouman (Deputy Manager Utilities), Mr. Alam

(Deputy Manager Utilities), Mr. Khalid Ejaz (Senior Deputy Manager

Spinning), Mr. Abaid Ullah (Senior Deputy Manager Textile Lab), Mr.

Jamshaid Yaqub (Senior Assistant Manager Utilities), Mr. Irfan Aziz (HR

Officer), Mr. Salman Qazim (Shift Engineer), Mr. Iftikhar (Shift

Engineer), Mr. Khalid (Shift Engineer), Mr. Bilal (Shift Engineer), Mr.

Zafar Niazi (Shift Engineer), Mr. Umer Mehboob (Shift Engineer), Mr.

Umar Faraz (Shift Engineer), Mr. Ahsan (Shift Engineer), Mr. Hamza

Abbas (Trainee Engineer), Mr. Afnan Amjad (Trainee Engineer) and

Mr. Zain Ul Abideen (Trainee Engineer)

in Ibrahim Fibres Limited for all their guidance and help. We are also

thankful to all the Supervisors, Operators and every Individual who

has helped us even a bit for the completion of this report.




12

PREFACE

This report produces a peer based review and learning

outcome about the working and processes of polyester fiber at a

plant. In this report we have tried to mention all those things which we

have learned during our internship. In the first section of this report,

Polymer Section is briefly explained. Basically all the chemicalprocesses needed in the production of polymer melt occur in this

section. Second section of this report is based on Utilities. Utilities are

those things which are necessary to run a plant. e.g. steam, N2 &

compressed air etc. This section is considered as the Heart of the Plant.

Third section of this report deals with Spinning and Fibre line Process.

This section is totally based on physical operations. Spinning is theformation of filaments by the use of spinnerets. Fibre Line is the area

where all of the drawing of fibres is done. Fibres acquire most of their

physical properties in this area. Last section is relevant to testing and

characterization of different materials in the whole plant, Textile Lab.

Safety Precautions about the plant are also discussed in this report.




13

SAFETY PRECAUTIONS

In order to avoid the hazards on the plant, company train its employees for the

safe handling and operation of materials and units installed on plant. Even a small

mistake on the plant can cause a serious damage so man, machine & material is

very important.

Personal Protection Equipments (PPEs) must worn in the plant premises.

Smoking is strongly prohibited on all areas of the plant because at different

places different flammable materials are under process and some

leakages may occur and so serious damage can occur.

Over speeding is prohibited on the roads because staff is always crossing

the roads and also tanks with explosive materials are present at different

places and anything hitting them may cause a serious danger.

Mobile phone is not allowed in plant area because electromagnetic waves

may disturb the sensitive control system.

For the training of internees, schedules are issued that means that for every

unit some guide is provided for the specific period of time and we are not

allowed to go in any area according to our desire.

Yellow marks are there on the steps that are odd as compared to other to

prevent injury of workers.

Yellow borders are also provided in front of computer control systems to

prevent the tripping of systems as they are very sensitive.

MSDS (material safety data sheets) are provided with every material for the

safe handling and storage of the materials.

Different water, gas and sand exhaust systems are provided for overcoming

fire.




14

COMPANY PROFILE

Ibrahim Fibres Limited Company was established in 1947 in Faisalabad, Pakistan

as a cloth trading business. In 1980, Ibrahim Textile Mills Limited was established

under the form of a manufacturing blended yarn. In 1982 and 1987 two more

companies were established (A.A. Textiles Limited and Zainab Textile Mills Limited).

In order to improve the efficiency and quality of its manufacturing units that

require a continuous uninterrupted supply of electricity, the Ibrahim Group has

established its Power Generation plant and now it is being expanded to cater for

the expansion of its manufacturing units. Power generating capacity of the

project is 31.8 MW based on heavy fuel oil. The plant and machinery of the project

comprises of 6 furnace oil generating sets, each having a capacity to produce

5.3 MW, supplied by Nigata Engineering Company, Japan. All these

manufacturing companies have now been merged into Ibrahim Fibres Limited.

Ibrahim Fibres Limited is incorporated in Pakistan as a public limited company

under the Companies Ordinance, 1984 and is listed on Karachi and Lahore Stock

Exchanges in Pakistan. The principal business of the Company is manufacture and

sale of Polyester Staple Fibre and Yarn. The registered office of the Company islocated at 1-Ahmed Block, New Garden Town, Lahore. The manufacturing units

are located at Faisalabad- Sheikhupura Road, in the Province of Punjab.

Allied Bank Limited

The consortium of Ibrahim Leasing Limited and Ibrahim Group assumed the

control of the Allied bank in August 2004 by injecting Rs 14.2 billion into the capital

of Allied bank for acquiring 325 million additional shares. Today Allied Bank's paid

up Capital & Reserves amount to Rs. 10.5 billion, deposit exceeded Rs. 143 billion

and total assets equal Rs. 170 billion.




15

The Allied Bank's story is one of dedication, commitment to professionalism,

adaptation to changing environmental challenges resulting into all round growth

and stability, envied and aspired by many.

Polyester Fibre Project

The Polyester Fibre Project is based on the engineering and technology supplied

by Zimmer AG Germany, who are market leaders in the Polyester Polymer

capacities supplied worldwide representing nearly 30% share in the world market.

The plant is equipped with Provox plus Distributed Control System (DCS) using SRX

process controllers providing a foundation for real time, effeicient and accurate

control and monitoring of the process of entire plant through ComputerIntegrated Manufacturing (CIM).

The Provox plus data provides access to historical process data for monitoring and

analyzing process conditions. Intelligent alarming techniques help enhanced

operator control capability to evaluate changing conditions and to respond

quickly to any process changes. The plant has one to one redundancy starting

from process control units up to all input/output modules enabling smooth and

consistent operation of the plant. The designed capacity of the project,

consumption of raw materials, utilities and quality of finished products are

guaranteed by German supplier.

Polyester Fibre Project IFL-l

Initiated in 1994 and operational since December 1996, Plant I has a capacity to

produce 200 tons/day of PSF in two lines of 100 tons/day each. Based on 24

hours/day operations of the poly condensation and spinning plant and on 20

hours/day operation of fiber lines, the installed annual manufacturing capacity of

the plant 70,000 tons of PSF.




16

Polyester Fibre Project IFL-ll

This plant has a single polymer line of 410 tons/day and three spinning and staple

fibre processing lines, each having capacity of 132 tons/day. The installed annual

manufacturing capacity of the plant is 138,600 tons of PSF per annum. The plant

supplier opted to start operations of spinning and staple fibre processing lines one

after other and the commercial production was started in October 2002.

Polyester Fibre Project IFL-lll

The Company has successfully implemented the balancing, modernization and

expansion of Polyester plant with a new project IFL-ll having a production

capacity of 600 tons per day. The commercial production of this plant has been

started in the month of April 2013.

The Polyester Fibre Division of the company produces wide range of the PSF of

different lusters and varieties including semi dull, bright, optical bright, anti pilling,

flame retardant and tri lobal with cut length of 32, 38, 44, 51 and 64 mm and

fineness of 0.8, 1.0, 1.2, 1.5, 1.7, 2.0, 3.0 and 6.0 denier.

The project is the first in Pakistan to start the production of dyed fibre and hollowfibre in siloconised and non-siliconised varieties. Some of the specifications of the

products produced are:

Sr # Parameters Unit Specification Max Tolerance +/-1 Denier d 0.8 0.04

2 Cut lengths mm 38 4 %

3 Tenacity g/d 6.8 0.2

4 Elongation % 21 3

5 Crimp No No./inch 13 16 Crimp Removal % Min 15 -

7 Crimp Stability % Min 60 -

8 Shrinkage % 5.0 1.0

9 Elec.Resistence Ω x 1011 Max 1.0 -

10 Moisture % Max 0.4 -

11 Color L - Min 92 -

12 Color b - Max 3.0 -




17

Ibrahim Fibres is situated at the integrated site of Ibrahim Group close to

Faisalabad, where nearly 50% of Pakistan's spinning capacity is located. The site

orientation allows for just in time delivery for over 80% of the customers. The textile

plants of group are also users of polyester staple fibre and this allows in housequality tests.

The group today derives its strength from a unique blend of entrepreneurial

ownership added with unparalleled skill of professionals.

Keeping up with the ever increasing awareness of quality and high standards, the

principle of continually improving the products and production techniques is

followed. A well-trained quality control department is responsible for ensuring that

the quality of all the products of the Company meets the most stringent

international standards. The people in this important activity are supported by

complete and modern chemical and textile laboratories. A further step to

strengthen the manufacturing efficiency, process and products was achieved

when the Company received ISO 9002 Quality Certification for its manufacturing

process.

The Company achieved net sales of Rs. 38,839 million during the year under

review as compared to Rs. 35,853 million during the previous year. The gross profit

earned during the year was Rs. 2,725 million as against Rs. 2,622 million earned

during previous year.

Today, the Group is managed by highly qualified team of professionals with vast

experience in their respective fields. Every department is headed by a

professional, qualified and experienced executive. At present Ibrahim Group has

total employment of 2958 individuals comprising of 1727 skilled persons, 879 semi-

skilled persons, 87 senior technical executives and 265 officers and managerial

staff.




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Product (PET) Introduction

The main product in this process is the Polyethylene terephthalate. However,

water is produced as a polycondensation by-product with no important

economic value.

Polyethylene terephthalate (PET) is a polycondensation polymer. It is most

commonly produced from a reaction of ethylene glycol (EG) with either purified

terephthalic acid (PTA) or dimethyl terephthalate (DMT), using a continuous melt-

phase polymerization process. In many cases, melt phase polymerization is

followed by solid-state polymerization.

This polymer is the most common thermoplastic polyester. It is often called just

“polyester”, which often causes confusion. PET is a hard, stiff, strong, dimensionally

stable material that absorbs very little water. It has good gas barrier properties

and good chemical resistance except to alkalis (which hydrolyze it). Its crystallinity

varies from amorphous to fairly high crystalline. It can be highly transparent and

colorless but thicker sections are usually opaque and off-white.

PET is widely known in the form of thermally stabilized films used for capacitors,

graphics, film base and recording tapes etc. It is also used for fibres for a very wide

range of textile and industrial uses. Other applications include bottles and

electrical components.

Process Summary for PET ProductionIn Ibrahim Fibres Limited, PET is generally produced direct esterification of purified

terephthalic acid (PTA) with EG. The first stage is to produce a mixture of ethylene

glycol ester ofterephthalic acid. This mixture of linear oligomers (mainly bis-

hydroxyethyl terephthalate BHET) is subjected to a further stage known as






20

Mass Balance for PET Process

Following assumptions are made for calculations:

1.

No impurities are present in the reactants

2. 100% conversion of reactants

3.

100% solubility of PTA in EG4.

By-products other than water are neglected

5.

No loss of expensive materials

E/T=1.03/1

Components In (kg/kg PET) Out (kg/kg PET)

MEG 0.33 -

PTA 0.86 -

PET - 1.00

Water - 0.19

Total 1.19 1.19




21

E/T = 2/1

Components In (kg/kg PET) Out (kg/kg PET)

MEG 0.64 -

PTA 0.86 -

PET - 1.32

Water - 0.18

Total 1.5 1.5

PTA SECTION

What is PTA?

It is 1, 4-Benzenedicarboxylic Acid with a chemical name of Pure Terephthalic

Acid - C6H4 (COOH) 2. It is commonly produced by the oxidation of p-xylene by

the oxygen in air. Some properties of PTA are listed in the following table:

Color White Crystalline Powder

Auto-ignition Temperature 495oC

Flash Point (Open Cup) 260 oC

Products of Combustion Carbon Oxides (CO, CO2)

Specific Gravity (15 oC) 1.51

Vapor Pressure (25o

C) 0.00158 PaParticle Size 70-160 microns

Impurities Acetic acid, Mo, Cr, Ni, Fe

pH 2.16

Molecular weight, g/mol 166.14




22

Melting point, oC 427

PTA (Pure Terephthalic Acid) is the basic raw material for the production of

Polyester. Polyester fibers based on PTA provide easy fabric care, both alone and

in blends with natural and other synthetic fibers. Polyester films are used widely in

audio and video recording tapes, data storage tapes, photographic films, labels

and other sheet material requiring both dimensional stability and toughness.

PTA Uses

1.

PTA, a white solid is a commodity chemical, used principally as aprecursor to the polyester PET, used to make clothing and plastic bottles.

2.

PTA is also used in the pharmaceutical industry as a raw material for

certain drugs.

3.

It is further used as filler in some military smoke grenades.

4.

PTA is also used in the paint as a carrier.

PTA Section Division

The whole PTA section deals with the storage, handling, charging and conveying

of this raw material.

Storage and Handling

PTA is supplied to IFL by the following two companies.

1.

Lotte Pakistan PTA Ltd.2. Siam Mitushi PTA Co. Ltd

Siam Mitushi provide PTA in containers with 22 tons each (container casing weighs

1.2 ton). The container charging crane in PTA section has a capacity to handle a

maximum load of 25 tons.




23

Daily consumption of PTA depends on the daily production of polyester plant.

Storage warehouse of PTA section can store a stock of one month.

Charging of PTA

In this process, PTA is charged into Buffer Silos with the help of rotary feeders. The

charging process is of two types:

1.

Bag Charging System

2.

Container Charging System

In Bag Charging system, PTA bags are taken on the top of charging station with

use of hoist system. The bags are then opened on a pan with a vibrating screen

beneath it. A vent pipe is also there to remove extra fine particles. This screen

removes any coarse particles present in the feed. This feed is then transferred to

a rotary feeder equipped with a bag filter to trap any fine particles that may rise

in the feeder. This feed further moves to a buffer silo. This silo opens up in a rotary

feeder. This feeder prepares batch to be moved for compression and finally to a

large storage silo.

The Container Charging system uses large containers to prepare batch for IFL-2

(can also be used for IFL-1). Containers are first loaded on a charging station that

is inclined to an angle of 25-30 degrees. The maximum elevation provided is 45

degrees. The container is opened and PTA is loaded in a rotary feeder after

passing through vibrating screens.

Initial mechanism for both types of charging systems is different while the

remaining steps are essentially same. PTA section has two bag charging systems

(new and old).

Conveying of PTA

In this process PTA is conveyed to the storage silos of second stage with the help

of compressed nitrogen gas. It is then conveyed, from the storage silos, to the

respective plants.




24

N2 is separated from air in UTY section. The gas is compressed to ~4.2 barg in Screw

compressors. There are total 8 compressors; 3 for IFL-1, 2 for IFL-2 and 3 for IFL-3.

Each compressor section maintains different outlet pressure, however, the suction

pressure (70-80 mbarg) is same for all the compressor sections. Capacities ofcompressors are listed in the following table:

Compressor Name Capacity Discharge Temp.

1204-K01 13.5 m3/min 165 oC

1204-K02 13.5 m3/min 165 oC

1204-K05 13.5 m3/min 165 oC

1204-K11 29.5 m3/min 135 oC

1204-K12 29.5 m3/min 135 oC

1214-K11 40 m3/min 230 oC

1214-K12 40 m3/min 230 oC

1214-K13 40 m3/min 230 oC

Each compressor has a filter at its inlet and outlet position, except the standby

compressor of IFL-3. A cooler is present at the discharge of each compressor.Temperature of discharged gas depends on the outlet pressure of respective

compressor and that is why outlet temperatures of exit N2 varies for all the three

compressor sections and that is why different water flow rates are maintained in

the coolers to obtain sufficient cooling. After cooling, the gas passes through bag

filters and then through the storage silos to fluidize N2 to different plants.

PTA is not allowed to come in contact with air because if it comes in contact with

10% air, it forms an explosive mixture. That is why N2 is used as a conveying

medium.




25

Process Flow Diagram

Main Equipment Used

Filter

There is a bucket type filter where nitrogen is filtered with the polythene type filter

medium that removes all the powdered and undersize particles from the

recovered nitrogen. The purpose of this filter is that no PTA will pass from the

compressor as it can damage the capital property of the compressor.




26

Compressor

Here In case of PTA Conveying and Storage we need a compressed inert gas. As

PTA is one of the explosive materials, so for the sake of convenience we have

selected compressed Nitrogen as a driving source of PTA due to its unique

property that it remains inert even at very high temperature. The Compressors are

rotary type screw compressors that compress the nitrogen up to 2.4-3.2 bars

pressure at nearly 250 °C. In screw type compressors the gas is compressed

between the threads of screws that generates very high pressure i-e ranging from

2.4-3.2 bars. The pressure of nitrogen in the conveying and storage lines is nearly

65-80 mbar that is responsible for the fluidization of PTA during the storage and

conveying operations.

Cooler

Compressed nitrogen from compressor contains a high temperature of nearly

250oC, which needs to be cooled to 40-60oC to avoid the auto-ignition with PTA.

For this purpose we cool the temperature of nitrogen to desired range with the

help of Shell and Tube heat Exchanger, where water after passing through the

strainer, installed to remove the suspended solid particles from water, is inserted

into the shell side of cooler where nitrogen is in tube. Both the fluids move in co-

current manner and water is collected into the drain vessel. The cooled nitrogen

is sent to the silos for fluidization of PTA.

Rotary Feeder

Rotary feeder is responsible for the transfer of required PTA at IFL-1, IFL-2 and IFL-

3. Rotary feeder provide the specific mass to a bed of nitrogen depending upon

the capacity of that bed. We have adjusted the Rpm or frequency of Rotary

feeder from the DCR depending upon the requirement of raw material at IFL-1,

IFL-2 and IFL-3 and pressure of nitrogen.






28

MEG Sampling

Samples are taken from the tankers before discharging them to IFL main tanks.

Color, viscosity and moisture content is tested. MEG should contain less than 1%

moisture content to pass the quality test.

MEG Unloading and pumping to Process lineUnloading is carried out with the help of a centrifugal pump. A strainer is present

at pump suction and a flow meter (micro meter motion sensor) followed by a filter

at pump discharge. The purpose of strainer (bucket type) and filter is to trap

unwanted objects from the flow. MEG then enters a 3 way valve. The valve directs

it to one of the two MEG storage tanks, 1107-T01, and 1107-T02 for IFL-1. One tankis filled at one time. The total capacity of the tanks is 2000 tons each. Each tank is

equipped with level transmitters which generate the low level alarm and high

level alarm if MEG level in tanks reaches the fixed set-points. The tanks are filled

up to a maximum level of 90%. Level transmitters are used to keep a check on the

level.

MEG is transported with the help of centrifugal pumps at 8-9 bar pressure to

participate in the reaction for the production of polyester. Each pump has a

strainer at its suction, to separate unwanted objects, and each pump has a

recirculation for safety purpose. Some properties of MEG are mentioned in the

following table:

Chemical Formula OH-CH2-CH2-OH

Molecular weight 62.03 g/mol

Boiling Point 197o

CAuto-ignition temperature 398 oC

Flash Point (closed cup) 111 oC

Specific gravity 1.116

Color Colorless




29

Odor Odorless

Taste Mild sweet

Purity 99.9%

MEG Uses1.

MEG is primarily used as a raw material in the manufacture of polyester

fibers and fabric industry.

2.

It is also used as an additive to prevent corrosion in liquid cooling systems

for PCs.

3.

One major use of MEG is as a medium for convective heat transfer.

4.

MEG also acts as a Dewatering agent.





30

Equipment Interlocks

Storage Vessels (1107-T01/T02, 1110-T01/T02, 1111-T01/T02) have following

interlocks:

1.

Level Alarm

EGR (Area Code – 3101) Process Description

The EGR unit is basically a recycling plant to enhance the purity of spent ethylene

glycol which is obtained from different plants of poly process plant. Basic

chemical reactions for the preparation of polyester are as follows:

The reaction shows that MEG is obtained as a by-product during the process. This

spent MEG is a contaminated by-product with monomers, aldehydes and

moisture.

The recovery process starts from 3101-V01 Vessel which holds spent glycol from

different parts of process plant. It is transported to a kettle-type evaporator which

maintains a pressure of ~260 mbarg vacuum and temperature of ~167oC. At this

vacuum condition SEG converts to vapor form while it has a boiling point of 197oC

at atmospheric pressure. SEG vapors are added to the 6 th plate of vacuum

distillation column. Top of rectifying section has a temperature of ~60 oC while the

bottom of stripping section has ~160 oC. Temperature is maintained with the help

of hot HTM coils in the bottom of column. ~99.5% pure ethylene glycol is obtained

at the bottom of 3101-C01. 70% level of fluid is maintained in the bottom of

column for the safety of HTM coils. The bottom product, REG, passes through a




31

plate and frame cooler (3101-E03); it exchanges heat with cooling water and

then enters to REG storage vessel (3101-V04). Samples of REG are taken to check

the quality. The MEG collected at the bottom is 25% of the total being used at the

plant. This is then forwarded to 1117-T01. The remaining sludge which containsimpurities is collected in the barrels and is sold as fuel.

Top product from 3101-C01, which consists of ~0.5% EG and remaining water

vapors, enters into a partial condensation vessel that is actually a heat exchanger

(3101-E02). Condensate, water, goes to the reflux drum (3101-V02) which supplies

a controlled amount of reflux at the top plate to maintain appropriate

temperature conditions. Also, the reflux is used enhance the purity of top product.

Vapors and any overflow from the partial condenser go to a drain vessel (3101-

V03). Vacuum pump (liquid ring) is attached with partial condenser, evaporator

and reflux drum to maintain vacuum conditions within the whole system. A knock

out drum is attached at the discharge of vacuum pump.

The distillation column is also equipped with temperature sensing elements,

control valves and controllers. The temperature is sensed by the thermocouples

and is converted into current amperes. A set point is given to each controller.

Whenever there is a change in the set point, a signal is generated in the feedback

system which is attached to Distribution Control System (DCS). The DCS responds

to the controller to set the flow rate of HTM to regulate temperature.

Main Equipment Used

Kettle type Evaporator

Kettle type evaporator is special type of evaporator designed especially for the

evaporation under evacuated conditions. It contains a kettle type structure

where heating coils are present.

In this evaporator the SEG (Spent Ethylene Glycol) is heated with the HTM in the

coil at 169 C and 260 mbar pressure. SEG contains MEG, water vapors and




32

aldehyde groups. The Boiling Point of MEG is 197 C. Under Vacuum water vapors

and MEG gets boiled at 169 C and collected at the Distillation Column and

sludge is discharged to waste column. It’s necessary to maintain 50% level of this

evaporator to avoid any damage of coils.

Distillation Column

Distillation Column is at 260 mbar pressure. It consists of 16 plates and feed is

provided at the 6th plate. It is bubble and cap type evaporator. The purpose of

bubble and cap is to provide maximum hurdles for the MEG vapors having low

latent heat that they lose their latent heat and condensed at the base. Only

water vapors are at the top of column that are condensed and partly returnedas a reflux and partly stored at the vessel. Reflux has two major benefits:

1.

It gives us maximum purity of MEG.

2.

It utilized the latent heat of MEG vapors and gets evaporated again without

disturbing our economy.

3.

In other words, heat required to evaporate Reflux water (Heat of

Vaporization) =Heat Released by the MEG vapors (Heat of Condensation).

Equipment InterlocksDistillation Column Unit (3101-CO1) have the following interlocks:

1.

Column Differential Pressure

2.

Pressure of Column

3.

Level of SEG storage vessel




33





34

HTM Section (Area Code – 3007)

Process DescriptionHTM stands for “Heat Transfer Media”. HTM is used as a source of heat for different

units of plant. Santotherm is used as HTM. HTM is heated in the furnaces. Partially

hydrogenated terephenyl (HTM) liquid circulates in coils where the combusted

natural gas or BC oil heats it in furnace. The trade name of HTM (Santotherm) is

“Therminol 66.” Therminol 66 fluid is designed for use in non-pressurized/low-

pressure, indirect heating systems. It delivers efficient, dependable, uniform

process heat with no need for high pressures. The high boiling point of Therminol

66 helps reduce thevolatility and fluid leakage problems associated with other

fluids. Some properties of HTM (Santotherm) are as follows:

Color Clear, Pale yellow liquid

Maximum moisture content 150 ppm

Flash point 184oC

Fire point 212 oC

Auto-ignition temperature 374 oC

Specific gravity 1.012

Density at 25 oC 1005 kg/m3

Optimum use range 0-345 oC

Dowtherm is another heating media which is used in vapor form. It is used to heat

reaction vessels (ES-1, ES-2, PP-1, PP-2, DRR etc.) by staying in the jacket of these

vessels. It has a low boiling point. Santotherm is used to exchange heat with this

heating media to convert it into vapor state. Some of its properties are listed as

follows:




35

Freezing point 2.3oC

Boiling point 243 oC

For heating of HTM, three furnaces are used. In IFL-1, there are two furnaces. One

of them is in operation while the other furnace is at standby position. The most

important thing is the flow in and out of furnace.

There are steam lines (25 bar, 6 bar) coming from boiler house to HTM area to

different places such as

1.

Pre heaters (Steam heaters)

2.

BC oil vessel

3.

HTM drain and make up vessel in HTM area

4.

Economizer

LPG gas (Liquefied petroleum gas) is used to provide initial spark for ignition and

BC oil or Natural gas is used as a fuel.

Air for combustion comes to the intake of the fan from atmosphere and

stoichiometric requirement of air for furnace is 20 % excess air for burning. Processused for sending air by fan to top of furnace is actually known as Force and Draft

Mechanism.

Discharge from FD fan goes to economizer having shell and tube arrangement.

The air freshly enters into the economizer at 49 oC approximately. it is in the shell

side and in tube side there are flue gases at ~330 oC. There is shell and tube

arrangement in economizer.

The air discharge from economizer at approximately 180 oC because flue gases

coming at 330 oC and they exchange heat with air after exchanging heat gases

retain the temperature of about ~220-225 oC.




36

BCO Cycle

From V03 vessel, BCO is pumped towards the furnace with the help of low pressure

pumps. V03 has a heating system in its shell which pre-heats BCO to ~100oC before

being pumped by low pressure pumps which increase its pressure to ~9 barg. Itthan goes to the suction of high pressure pumps which increase the pressure

energy to ~35 barg. The discharge passes through a pre-heater which uses 25 bar

steam as a heating medium. BCO then enters the furnace and it is atomized with

the help of an atomizer.

BC oil which is used for burning and is given a set point of 130oC. For BC oil

transportation from vessel to furnace high pressure pumps (Gear pumps) are

used. The flame of gas burning in furnace is blue while the flame of oil burning is

yellow (Blue flame is stronger than yellow).

It is important to pre-heat the BCO, otherwise, cool BCO will disturb the

temperature profile of the furnace. Thus disturbing the whole process.

HTM CycleHTM is built up in a 3007-V01 vessel. Its level is checked with the help of a Magnetic

Level Indicator. It is then moved to 3007-V02 vessel at 25 m. If the level of 3007-

V01 falls, then barrels of HTM are charged each weighing 230 kg. The level of 3007-

V02 is maintained at 50%. If there are any leakages in the HTM system, then they

are directed to 3007-V04 at 0 m.

HTM is used as two systems. In coils as liquid and in vessel boundaries as vapors.

Santotherm is used in the primary cycle where it is heated in the furnace. This

Santo therm then moves in coils to a secondary cycle where it is used to convert

Dowtherm into vapor state in an evaporator. This Dowtherm is used in the linings

of the vessel to maintain the temperature of the mixture and to make sure efficient

heat transfer throughout.




37


Main Equipment Used

Furnace

Furnace is there to heat the santotherm which is our HTM to a temperature of 325

oC from 292 oC. The Furnace is operated with Heavy Furnace Oil (HFO), after pre-

heating the HFO at pre-heater is sprayed at the top of furnace with the help ofan Atomizer. Atomizer Creates a fine spray of HFO for easy and complete

combustion. Another source of fuel for the Furnace is natural Gas, Natural Gas is

being provided by Utility Department at the required temperature and Pressure.

Air is taken from atmosphere, pre-heated in economizer and then provided to the




38

damper with the help of blower and then injected both natural gas and air in a

required ratio to the Furnace. It is then started and the HTM is heated with

Conduction, Convection and Radiation mode of heat transfer.

Conduction

This Mode of heat transfer is effective in those coils which are in direct contact

with the burner.

Convection

This mode is effective when the flue gases moves in bulk due to density and

momentum difference.

Radiation

This mode is effective in the whole body of furnace.

Stack

Stack is for the emission of flue gases after passing through the economizer. Stack

have a variable area to reduce the emissions of solid contents and increase the

kinetic head of gases.

Pre-Heater (HFO)

Pre-Heater is available for HFO which pre-heats the HFO using 6 bar steam

followed by 25 bars steam at two different stages. The Purpose of this pre-heater

to save our fuel for maximum heat economy. This step economizes our process by

providing us maximum efficiency.

Atomizer

Atomizer is a device which is used to convert the jet of any fuel or liquid into fine

spray in order to increase the effective surfaces throughout the reactor or

furnaces.




39

Blower

Blower is an instrument that is used to convert pressure head of air to its kinetic

head and increases the flow rate for effective combustion.

Economizer

Economizer is also a pre-heater that uses the flue gases and pre-heat the air

coming from blower before providing to the furnace in order to have the

maximum utilization of waste heat.

Damper

We provide natural gas and warm air to damper that maintains a specific air to

fuel ratio for maximum oxidizing flame. As the reducing flame will cause more

toxic emissions that needs to be processed before emitting into the air.

Ignition Fuel

LPG is the ignition fuel of Furnace in order to have effective start up.

Equipment Interlocks

Furnace Unit (3007-F01/F02) has the following interlocks:

1.

HTM Flow Pressure

2.

Air Inlet Pressure

3.

FD Fan (Blower) Load

4.

Fuel Gas Pressure

5. Ignition Gas Pressure

6.

Fuel Oil Temperature

7.

Fuel Oil Pressure8.

Discharge Pressure Pump Load

9.

Blocking Tightness Control

10.

Flame Eye Intensity




40

TDO Section

Process Description TDO or Titanium dioxide is a white powdered solid (mol. wt. 79.9 g/mol). In fiber

making process, it is used as dulling agent in the second stage of esterification

process. It is used to make products of different brightness. For making a semi-dull

product, the concentration of TDO in the solution is 10% and 0.3% by weight of

PET in the final product. On the other hand, a bright product must have 3%

concentration of TDO in solution and 0.03% by weight of PET in the final product.

It also has following advantages for the final product,

1.

TDO provides matt finish to the final product.

2. It increases the durability of the product.

3.

TDO Anatase has high refractive index close to diamond, which causes

glitter-ness.

4.

TDO also gives hardness to the product i.e. on a scale of 0-10, where talc

has zero hardness and diamond has maximum of 10, TDO has hardness of

5.5 – 6.5 Mohs.

A 500 kg bag of TDO is added into 1307-V01 vessel via a hopper assembly. Now,

500 kg of fresh MEG is added to this vessel to make a 50% concentration mixture.

Then the mixture is agitated for 4 hours. This mixture then moves to 1307-V07 where

1610 L of EG are added to reduce the concentration of solute to 20%. It is again

mixed for 1 hour before moving it to centrifuge (1307-A02). The centrifuge

undergoes through three steps during its operation:

1.

Classifying – Fine and oversized particles are classified and this process lasts

for 50 minutes.

2.

Dispersing – Dispersion of Oversized particles with MEG and this step lasts for

~20 minutes.




41

3.

Discharging – Discharging of oversized particles by MEG to Pearl Mill and

this step lasts for ~5 minutes.

Undersized particles are separated and moved to 1307-V02 in which 1800L of EG

are added to make the mixture concentration to 10%. Pearl Mill grinds the oversize

particles by using a Muller which has fine particles of Zirconium dioxide of

diameter 0.8 micron. Ground particles form pearl mill are again moved to 1307-

V01 vessel.

Mixture from 1307-V02 is now separated into two lines for making products of

different properties i.e. semi-dull and bright. 1307-V03 is used for making semi-dull

product of 10% TDO concentration. Bright product is made up in 1307-V04 vessel

from where it enters 1307-V05 vessel in which 4363 L of EG are added to reduce

the concentration of TDO up to 3%.







43

The true solution prepared in the 2nd equation contains 3250 Liters of MEG along

with 75 kg of catalyst. This solution is charged into the catalyst feed hopper from

where it moves to the 1402-V01 batch preparation tank. This vessel can be

operated at a maximum of level of 95% and minimum of 35%. Flow counters areattached which send the measured quantity of EG in the catalyst vessel. The

batch in the 1402-V01 is then sent to a filter in which batch is filtered for any

suspended solids. Clear solution is now ready for the paste preparation tank.





44

Paste Preparation Section

Process DescriptionIn this stage all the essential components are mixed in specific amounts. A paste

is formed which is then sent to main reaction vessels. Following ingredients are

added into this vessel:

1.

MEG

2.

PTA

3.

Catalyst

PTA and MEG are charged in a specific mole ratio here we call it E/T ratio.

Normally two moles of MEG require one mole of PTA to react. In the paste

chamber the E/T ratio is set as:

=

= 1.12

Essentially no serious reaction is occurring in the paste preparation chamber that

is why the ratio is set as 1.12. The ratio highly depends on the production rate of

plant. Addition of 0.86 mol of MEG is carried out in the later reaction stages to

meet the required mole ratio.

In the paste preparation vessel mostly Recovered MEG from EGR and Column

MEG are added to run the process economically. However, fresh MEG is also

added to maintain a certain purity level. Fresh MEG is 99.9% pure. Flowmeters

carefully control the flow rates of EG entering the vessel.

PTA is added into the paste preparation vessel from the day silo. A rotary feeder

directs PTA to the Shank System, a motor operated assembly. Shank System is an




45

arrangement to carefully control the flow rate of PTA in order to achieve a

specified mole ratio.

The catalyst in the 1402-V01 vessel is directed towards paste tank. The capacity

of the tank is 29m3 and is operated at 90% level. The temperature in this tank is

around 45oC which is way lower than the actual process condition. The paste is

constantly agitated with the help of a fix speed agitator. The paste in the tank is

provided a residence time of 3 hours and is then moved to the first esterification

tank. The density of the final paste is 1.393 g/cm3.

Due to the addition of catalyst some amount of product (i-e monomers and

oligomers) start forming in this stage. Thus in later stages reaction completion will

require less time.





46

Main Equipment Used

Shank System

Shank System contains an inclined plate that rotates at a specific speed to

maintain mole ratio between PTA and MEG. It is situated at the base of Rotary

Feeder of Day Silo.

Paste Mixer

Paste mixer receives the raw material from shank system and it has three lines of

MEG. First is fresh MEG, 2nd is REG and 3 rd is recovered MEG. We have maintained

the mole ratio of PTA and MEG is 1:1.12 at the paste mixer. Agitator is present at

the top of paste mixer in order to mix the catalyst and raw material for a specific

time.

Esterification (ES-I and ES-II)

Process DescriptionTwo reactions are involved in the preparation of polyester from raw materials. The

first one is esterification, which takes place in ES-I and ES-II, and the second is

polycondensation which takes place in PP-I, PP-II and DRR.

The main reaction takes place in a large esterification reactor 1424-R01 (ES-I)

which has a capacity of 50m3. It is a Continuous Stirred-Tank Reactor (CSTR) which

is maintained at a level of 55%. The tank is heated internally with the help of 9

spiral Santo therm coils. An external jacket contains Dow therm vapors which do






48


ES-1




49

ES-2




50

Polycondensation

Process DescriptionThe second reaction of polycondensation takes place in following three reactors:

1.

PP1

2.

PP2

3.

DRR

In these reactors, monomers and oligomers undergo condensation

polymerization with elimination of MEG. Value of degree of polymerization that is

achieved in these stages is ~104. The produced monomer has two functional

groups; carboxl group (COOH) and hydroxyl group (OH). It goes through step-

growth polymerization, where the growth of the molecules occurs through the

reaction of the two functional groups

PP1 is the first reactor of this operation. It does not contain any stirrer. The reactor

is operated at 256oC and 0.12 bar vacuum pressure. Residence time in PP1 is ~1

hour. The EG vapors that evaporate from the top are captured in a scrapper

condenser. This system consists of a liquid EG shower at the top which is used to

condense the vapor. Vapors and liquid are in direct contact with each other. At

the bottom, a scrapper shaft is attached which scraps any solids that may deposit

in the condenser walls. The level of the tank is measured with the help of capacitor

type level indicator. This consists of a 2 rods, one has reference current passing

through it whereas the second rod senses current from the tank. The change in

the current with respect to the reference rod is calibrated as the level indication.




51

The product from PP1 is conveyed to PP2 via HTM jacketed lines. PP2 is equipped

with an agitator which continuously cuts the viscous solution and generates new

surfaces. Residence time in PP2 is ~0.85 hour and it operates at ~273oC and 0.02

bar vacuum pressure. Moisture content of the tank is ~10%. Rate of evaporationfrom this reactor is higher because it operates at high temperature and low

pressure. Vapors are, partially, condensed in the scrapper condenser. The level of

the solution in the PP-2 is measured by not only capacitor system but also a

radioactive level measuring system. Radioactive system uses radioactive Cobalt-

60 at the bottom of the tank. A detector is installed at the top which measures

the radioactive intensity. When the level of the tank rises, the intensity at the top

reduces. This reduction in intensity is calibrated against the level measurement.One of the main reasons to use radioactive elements for level measurement is

that the fluid in PP2 becomes highly viscous and other sensors can’t measure the

level accurately.

DRR (Disc Ring Reactor) is a horizontal reactor whose primary purpose is to

achieve a specific value of intrinsic viscosity (0.6). There is a shaft across the length

of DRR which continuously cuts the material with the help of rings. The material is

exposed to high temperature (~280oC) and very low pressure.

EG and moisture evaporates from DRR and pass through a scrapper condenser.

Uncondensed vapors passes through a jet system. The jet system entertains the

vapors from PP2 and DRR. Vapors after passing through the jet system (I, II & III)

undergo sudden expansion which produces vacuum and condenses the vapors.

Uncondensed vapors from the jet system passes through a vacuum system which

uses vacuum pumps. Here maximum portion of vapors is condensed,uncondensed part is vented into the atmosphere. That part mainly contains

aldehydes and ketones due to which it is not condensed.

Product from DRR is filtered through candle filters which have stainless steel

candles and it is then transported to spinning section via gear pumps.




52


PP-1 and PP-2

DRR




53

Main Equipment Used

Scrapper Condenser

Scrapper Condenser is used to condense the vapors of MEG and water at the

top of PP-1,PP-2 and DRR.It contain inclined plates and hurdles for vapors so that

they lose their latent heat .Vapor condensate is treated as SEG and the remaining

is sent to Ejector System.

Ejector System

In this system vapors are compressed in the form of jet and then expanded in a

vessel that cause two fruitful effects.

1.

It condensed the maximum vapors.

2.

It generates the vacuum in the lines.

Vacuum Pump

Vacuum Pump generates vacuum by ejecting the gases present in the line with

its suction power and after condensing them in its casing discharge into the vent.

Fume Arrestor

Fume Arrestor is present at the top of every storage vessel which contains the

flame-able liquids. it catches the fumes present at the different temperature of

vessel and reduce the internal vapor pressure that act as a safety for the system.




54

Materials Safety Guide

MEG Safety

Emergency Overview Warning! Harmful or fatal if swallowed. Harmful if inhaled or absorbed through

skin. May cause allergic skin reaction. May Cause irritation to skin, eyes, and

respiratory tract. Affects Central nervous system.

InhalationVapor inhalation is generally not a problem unless heated or misted. Exposure to

vapors over an extended time period has caused throat irritation and headache.

May cause nausea, vomiting, dizziness and drowsiness. Pulmonary edema and

central nervous system depression may also develop. When heated or misted, hasproduced rapid, involuntary eye movement and coma.

IngestionInitial symptoms in massive dosage parallel alcohol intoxication, progressing to

CNS depression, vomiting, headache, rapid respiratory and heart rate, lowered

blood pressure, stupor, collapse, and unconsciousness with convulsions. Death

from respiratory arrest or cardiovascular collapse may follow. Lethal dose in

humans: 100 ml (3-4 ounces).

Skin Contact

Minor skin irritation and penetration may occur.

Eye ContactSplashes may cause irritation, pain, eye damage.

Chronic ExposureRepeated small exposures by any route can cause severe kidney problems. Brain

damage may also occur. Skin allergy can develop. May damage the developing

fetus.

Aggravation of Pre-existing ConditionsPersons with pre-existing skin disorders, eye problems, or impaired liver, kidney, or

respiratory function may be more susceptible to the effects of this substance.




55

First Aid Measures

InhalationRemove to fresh air. If not breathing, give artificial respiration. If breathing is

difficult, give oxygen. Call a physician.

IngestionInduce vomiting immediately as directed by medical personnel. Never give

anything by mouth to an unconscious person. Get medical attention.

Skin ContactRemove any contaminated clothing. Wash skin with soap and water for at least

15 minutes. Get medical attention if irritation develops or persists.

Eye ContactImmediately flush eyes with plenty of water for at least 15 minutes, lifting lower

and upper eyelids occasionally. Get medical attention immediately.

Note to PhysicianGive sodium bicarbonate intravenously to treat acidosis. Urinalysis may show low

specific gravity, proteinuria, pyuria, cylindruria, hematuria, calcium oxide, and

hippuric acid crystals. Ethanol can be used in antidotal treatment but monitor

blood glucose when administering ethanol because it can cause hypoglycemia.

Consider infusion of a diuretic such as mannitol to help prevent or control brain

edema and hemodialysis to remove ethylene glycol from circulation.

PTA Safety

Emergency OverviewThis product has been evaluated and does not require any hazard warning on

the label under OSHA criteria. Handling and/or processing of this material may

generate airborne fibers and particles which can cause mechanical irritation of

the eyes, skin, nose and throat.

Skin contactNo significant health hazards identified.

Inhalation No significant health hazards identified.

Ingestion No significant health hazards identified.




56

Eye contactNo significant health hazards identified. Particles or fibers may cause slight

discomfort similar to getting dust in the eye.

First Aid Measures

Eye Flush eyes with plenty of water.

Skin Wash exposed skin with soap and water.

Inhalation If adverse effects occur, remove to uncontaminated area. Get medical

attention.

Ingestion If a large amount is swallowed, get medical attention.

PET Safety

Emergency OverviewProduct form varies: chips, dice noodles or lace. Colors vary: milky white to black;

several levels of translucence or luster. Under normal conditions of use, this

product is not expected to create and unusual emergency hazards.

Polyesters can burn if exposed to flame. Molten polymer generates small amountsof volatile degradation products (off-gases), one of which is acetaldehyde.

Acetaldehyde vapors form explosive mixtures with air that can spontaneously

ignite (auto-ignite) at temperatures above 347ºF (175ºC).Combustion products

may include compounds of carbon, hydrogen, and oxygen; exact composition

depends on conditions of combustion.

In the event of fire, use normal firefighting procedures to prevent inhalation of

smoke and gases.

InhalationIrritation of the upper respiratory tract, coughing, and congestion may occur.

SkinMolten resin will cause thermal burns.

AbsorptionNot applicable






58

Boiler (Area Code-3910)

Boilers are pressure vessels designed to heat water or produce steam, which can

then be used to provide water heating to a building. In most commercial building

heating applications, the heating source in the boiler is a natural gas fired burner.

The basic consumption of steam is in the fiber draw line, heavy furnace oil

& polymerization section.

TypesBoilers are classified into different types based on their working pressure and

temperature, fuel type, size and capacity, and whether they condense the water

vapor in the combustion gases.

Two primary types of boilers include:

1.

Fire Tube Boilers

2.

Water Tube Boiler

Both types of boilers are used in IFL.

Fire tube boilers

Fire tube boilers consist of a series of straight tubes that are housed inside a water-

filled outer shell. The tubes are arranged so that hot combustion gases flow

through the tubes. As the hot gases flow through the tubes, they heat the water

surrounding the tubes. The water is confined by the outer shell of boiler. To avoid

the need for a thick outer shell fire tube boilers are used for lower pressure

applications.






60

Condenser

A condenser ensures that all steam is condensed before being pumped back into

the deaerator and on into the boiler.

Damper

A damper is used to make the mixture of air and fuel i.e. to set the air to fuel ratio.

Economizer

An economizer is a heat exchanger that is placed in the exhaust from a boiler.

Fuel

The source of heat for a boiler is combustion of any of several fuels. In IFL two

sources are used:

1.

Natural gas (mostly used)

2.

Furnace oil (stand by)

Process DescriptionThe steam condensate (70%) returning from the plant comes to the condensate

vessel (VO2), after that condensed steam is sent to the vessel (VO3) where two

condensers are used to condense the steam of VO1, VO2 and VO3. Then by using

low pressure pumps (PO4, PO5) condensate is sent to the boiler feed water tank

where a deaerator is also attached to remove the air from the steam

condensate. In this vessel chemicals are added to condensate.

1.

Hydrazine - for removal of free oxygen

2.

phosphate – anti corrosion agent

After the feed water tank the condensate is pumped by boiler feed pumps (PO1,

PO2 and PO3) to the boiler. The condensate along with 30% de-mineralized waterenter the boiler on the shell side and converts to the vapors form by heat transfer

from the fire entering from the tube side. The level of water in Boiler is 2/3 of total

volume of boiler. The steam from the boiler then enters the super-heater at 25-

bar pressure and the steam from the super-heater exits at about 250°C. The

http://en.wikipedia.org/wiki/Combustion

http://en.wikipedia.org/wiki/Fuel

http://en.wikipedia.org/wiki/Fuel

http://en.wikipedia.org/wiki/Combustion




61

steam at 25 bar pressure is then divided in to 3 different pressures by steam

header;

1.

25-bar

2.

10-bar3.

6-bar







63

Nitrogen Generation (Area Code – 4400)

Why Nitrogen is Important?Nitrogen is a chemical element with symbol N and atomic number 7. At room

temperature, it is a gas of diatomic molecules and is colorless and odorless.

Nitrogen is a common element in the universe, estimated at about seventh in total

abundance in our galaxy and the Solar System. On Earth, the element is primarily

found as the gas molecule; it forms about 78% of Earth's atmosphere. The element

nitrogen was discovered as a separable component of air,

by Scottish physician Daniel Rutherford, in 1772.

Many industrial compounds such as ammonia, nitric acid,

organic nitrates (propellants and explosives), and cyanides, contain nitrogen. The

extremely strong bond in elemental nitrogen dominates nitrogen chemistry,

causing difficulty for both organisms and industry in converting the N2 into

useful compounds, but at the same time causing release of large amounts of

often useful energy when the compounds burn, explode, or decay back into

nitrogen gas.

Production

Nitrogen gas is an industrial gas produced by the fractional distillation of liquid air,

or by mechanical means using gaseous air (i.e., pressurized reverse osmosis

membrane or pressure swing adsorption). Commercial nitrogen is often a

byproduct of air-processing for industrial concentration of oxygen for steelmaking

and other purposes.




64

Process DescriptionIn Ibrahim Fibres Limited, nitrogen is separated from air by using Pressure Swing

Adsorption technique. Primarily, nitrogen is classified into two types depending on

its quality and nature of use; Technical Nitrogen and Pure Nitrogen.

Nitrogen Generation Plant Capacity

IFL 1,2 185 Nm3/hr

IFL 3 220 Nm3/hr

Technical Nitrogen

Nitrogen grade which contains less than 2% oxygen. This grade is obtained,

immediately, after the molecular sieves. Technical nitrogen is used to fluidize PTA

for transferring it from one place to another. It is also used in some level indicating

instruments and to transport materials by exerting a specific head.

Pure Nitrogen

Nitrogen grade which contains less than 10 ppm oxygen concentration is called

Pure Nitrogen. Pure nitrogen has limited applications in polyester plant. It is used

in most critical places, such as reactors, which require inert atmosphere and

proper nitrogen blanketing.

Pressure Swing Adsorption

Pressure swing adsorption (PSA) is a technology used to separate some gas

species from a mixture of gases under pressure according to the species'

molecular characteristics and affinity for an adsorbent material. It operates at

near-ambient temperatures and differs significantly from cryogenic distillation

techniques of gas separation. Specific adsorptive materials

(e.g., zeolites, activated carbon, molecular sieves, etc.) are used as a trap,

preferentially adsorbing the target gas species at high pressure. The process then

swings to low pressure to desorb the adsorbed material.




65

Pressure swing adsorption processes rely on the fact that under high pressure,

gases tend to be attracted to solid surfaces, or "adsorbed". The higher the

pressure, the more gas is adsorbed; when the pressure is reduced, the gas is

released, or desorbed. PSA processes can be used to separate gases in a mixturebecause different gases tend to be attracted to different solid surfaces more or

less strongly. If a gas mixture such as air, for example, is passed under pressure

through a vessel containing an adsorbent bed of zeolite that

attracts oxygen more strongly than it does nitrogen, part or all of the oxygen will

stay in the bed, and the gas coming out of the vessel will be enriched in nitrogen.

When the bed reaches the end of its capacity to adsorb oxygen, it can be

regenerated by reducing the pressure, thereby releasing the adsorbed oxygen. Itis then ready for another cycle of producing nitrogen enriched air. Using two

adsorbent vessels allows near-continuous production of the target gas. It also

permits so-called pressure equalization, where the gas leaving the vessel being

depressurized is used to partially pressurize the second vessel. This results in

significant energy savings, and is common industrial practice.




66

The process starts with the compression of air (till 8 bar) in double-stage rotary

screw type PD compressors. Compressed air has a temperature of 33-34oC. It

passes through dryers which use chilling effect, thus lowering the temperature to

point where moisture disengages from the gas. Now, air temperature is reducedto 20oC and it is stored in storage vessels (4300-VO1, VO2).

Air from storage vessels enter into a buffer vessel (4300-VO1). The function of this

buffer vessel is to absorb sudden pressure surges. From 4300-VO1, air enters into a

vessel which contains carbon molecular sieves. Air enters at high pressure.

Oxygen gas is entrapped into the carbon molecular sieves due to its small

molecular size while air, containing less than 2% Oxygen at 6.7 bar, exits through

the vessels. This stream is called Technical nitrogen and it is stored in a vessel.

Pure nitrogen is produced by passing technical nitrogen stream through a reactor

(4300-RO1) which contains Palladium catalyst. Reactor is fed with controlled

amount of hydrogen to reduce oxygen gas to water. Exothermic reaction occurs

and a temperature of 185oC is produced. Outlet stream is cooled by enhancing

the heat transfer area and through water. The gas passes through a desiccant

chamber with absorbs moisture from the stream. Now, pure nitrogen stream is

available for storage and use.




67


ApplicationsOne of the primary applications of PSA is in the removal of carbon dioxide (CO2)

as the final step in the large-scale commercial synthesis of hydrogen (H2) for use

in oil refineries and in the production of ammonia (NH3). Refineries often use PSA

technology in the removal of hydrogen sulfide (H2S) from hydrogen feed and

recycle streams of hydrotreating and hydrocracking units. Another application of

PSA is the separation of carbon dioxide from biogas to increasethe methane (CH4) content. Through PSA the biogas can be upgraded to a

quality similar to natural gas.

PSA is also used in




68

1.

Hypoxic air fire prevention systems to produce air with a low oxygen

content.

2. On purpose propylene plants via propane dehydrogenation. They

consist of a selective media for the preferred adsorption of methane

and ethane over hydrogen.

3.

Small-scale production of reasonable purity oxygen or nitrogen from air.

PSA technology has a major use in the medical industry to produce

oxygen, particularly in remote or inaccessible parts of the world where

bulk cryogenic or compressed cylinder storage is not possible.

4.

Nitrogen generator units which employ the PSA technique to produce

high purity nitrogen gas (up to 99.9995%) from a supply of compressed

air.

Cooling Towers

Basics

The equipment which are used to cool water based on the difference between

wet-bulb and dry-bulb temperature of air. There are two basic types of cooling

towers:

1.

Natural draft cooling towers

2.

Mechanical cooling towers








71

Some specifications of cooling towers are mentioned as follows:

Process Water Cooling Towers

IFL-1 process water cooling tower 3



Cooling water supply 34oC

Cooling water return 42oC

Chiller Water Cooling Towers

IFL-1 chiller water cooling tower 3IFL-2 chiller water cooling tower 1

IFL-3 chiller water cooling tower 3

Chiller water supply 34oC

Chiller water return 39oC

WATER TREATMENT

Water Treatment plant is a very important part of Utilities Section.

Water required:We need three type of water at IFL Plants:

1.

Soft Water

2.

Demineralized Water

3.

Drinking water

Purpose

Water treatment plant is responsible for the generation of the required water.






73

ions to get separate from the raw water we provide osmotic pressure on the outer

shell that helps us to separate the maximum ions on the membrane.

Degasser

Degasser is equipment used to remove CO2 from soft water. It consists of a

vertical column that has packing’s (Rashing Rings).

We provide feed from the top and air from the base that helps the CO2 to escape

from the soft water.

Mixed Bed Ion Exchanger (Demineralization)

Mixed bed Ion Exchanger consists of Cathodic and Anionic Resins, that removes

maximum ions from the soft water and reduces the conductivity of water up to

one micro Simons per centi meter. These resins become inactive after few days.

We doze 5% by volume NaOH and HCl for the regeneration of these resins. HCl is

effective for Anodic resins and NaOH is effective for Cathodic Resins.

Process DescriptionRaw water from the source is pumped by centrifugal pumps to Multi Layer Filter.

In Multilayer Filters we remove maximum suspended impurities. The capacity of

Multilayer Filter is 4.5 m3/hr. Water just after the Multilayer Filter is dozed by HCl.

HCl maintains a pH of 6.5 in the filtrate. After this the acidic water is filtered in

Bucket Filters. The Purpose of HCl dozing is to convert CaCO3 into CaCl2. Calcium

chloride has large particle size than the mesh no of Permeable Membrane of RO

Section. The reaction that takes place at RO is given below:

CaCO3 + 2HCl CaCl2+ CO2+H2O

RO plants reduce the conductivity of raw water from 3000 uS/cm to 65 uS/cm,

which is our soft water. The Rejected water of the first RO assemblies is then passed

to the next RO plants for further generation of soft water. After these plants the






75

CHILLERS

A chiller is a machine that removes heat from a liquid via a vapor-compression

or absorption refrigeration cycle. A chiller is usually factory assembled and

shipped to the facility where final electrical and plumbing connections are made,

but may be shipped in sections for field assembly. It has four primary components:

the compressor, the compressor drive, the evaporator, and the condenser.

Chillers can be categorized based on the type of compressor. Usually occurring

types of chillers include:

Electric Chiller

Steam Absorption Chiller

However, the choice of chiller is affected by the following decisions:

First Cost

Operation Cost

Maintenance Cost

Life Cycle Cost

In Ibrahim Fibers Limited, Polyester plant we in total have 11 chillers at the utility

section. These include both types of chillers. Chillers are used to chill (cool) the

water. The chilled water circulates in the plant through a closed loop. Each chiller

along with the phenomena is discussed further:

Electric ChillerElectrically driven chillers utilize electric motors to drive the compressor. These

chillers can be further categorized according to the type of compressor which is

used. Few of the types include

Reciprocating Compressor Chillers use cylinders with pistons acting as

pumps to increase refrigerant pressure. Compressors may have anywhere

http://en.wikipedia.org/wiki/Vapor-compression_refrigeration

http://en.wikipedia.org/wiki/Absorption_refrigerator

http://en.wikipedia.org/wiki/Absorption_refrigerator

http://en.wikipedia.org/wiki/Vapor-compression_refrigeration






77

Process Description

Electric Chiller follows exactly the refrigeration cycle in thermodynamics. The main

components of this chiller are discussed individually:

Compressor Drive

The compressor drive or pump is responsible for suction of refrigerant vapors from

evaporator to the discharge in compressor.

Compressor

The compressor receives the refrigerant vapors from pump and compresses it

down to achieve high pressure. The vapors are then forwarded to condenser.

Condenser

The condenser acts as a shell and tube heat exchanger and exchange of hest

occurs between WC and refrigerant vapors causing vapors to condense to a

liquid form.

Evaporator

Here the l high pressure condensed refrigerant is atomized resulting in evaporation

due to very low boiling temperature ultimately creating cooling effect. The

condensate is prayed on the tubes carrying WCC. The chilled water exchanges

heat and leaves the chiller at 6-7˚C. The cycle goes on and the vapors are sucked

again by the pump.






79

Type Centrifugal water cooled

Company Trane

Refrigerant LiBr Solution

Capacity 550 refrigerant tons/hrWC In temp. 30˚C

WC Out temp. 35˚C

WCC In temp. 11-12˚C

WCC Out temp. 6˚C

Process DescriptionThis chiller also follows the refrigeration cycle with the addition of few things. By

being double stage chiller it is 30 % more efficient in providing cooling effect. The

main components of this chiller are further discussed in detail individually:

High Temperature Generator (HTG)

In HTG the 6 barg steam is running in the tubes causing the dilute LiBr solution to

vaporize the water and become a saturated solution. The vaporized vapors are

passed to LTG.

Low Temperature Generator (LTG)

In LTG the water vapors from HTG cause further evaporation from the LiBr solution

present already. The vapors altogether go right to the condenser.

Condenser

The condenser is responsible for exchanging heat between WC and water vapors

from generator. The WC carries away the heat of water vapors eventually causing

the vapors to liquefy.




80

Evaporator

The condensed water vapors are then sprayed over the tubes carrying WCC. The

water vapors are passed through atomizer which causes evaporation which in

turn provides the cooling effect in this area. Water is chilled in here and the vapors

are then attracted by the absorber. Here water serves as the refrigerant.

Absorber

Absorber contains the rejected saturated LiBr solution from HTG and LTG. LiBr

being hygroscopic attracts away the water vapors from evaporator and

becomes diluted again. This cycle goes on like this. It is a closed loop cycle i.e.

refrigerant doesn’t leave the system.





81

Spinning Section

Some of the main parts of spinning section includes:

Heat Exchanger Heat Exchanger is at the 13M of IFL-1. It helps to attain the temperature of PET at

288 C. The HTM used in the Heat Exchanger is Santotherm. The line of PET is

provided a continuous jacket of Dowtherm to maintain the temperature and

specific flow rate. The Complex arrangement of lines of PET is for the generation

of homogeneity mixture under some static mixers.

Spin PumpsIFL-1 has two lines of spin pumps. Each line contains 30 pumps called as positions.

There are 5 assemblies of 6 positions. Each spin pump is provided a feed at 288 C

and at 70 bars pressure. Each pump is screw type and has a throughput 2268

g/min.

Spin PackSpin Pack has two types on the basis of number of holes at IFL.

1.

3750 Holes (Circular)

2.

2250 Holes (Trilobal)

Filaments from the spin pack is drawn in a 50mm draw section. The spin pack is

changed after 48 days for semi dull product and after 38 days for circular bright.

After this we regenerate the spin pack in auxiliary workshop. So in the first step,




82

spin pack is removed out from specified spinning position with the help of pack

manipulator. Then it is brought to auxiliary workshop by a trolley.

Quench AirAir coming from A/C Section is at 21 C and 85% Humid, known as Quench Air. This

air is provided through the air filter just after the spinet. Air is provided to the filers

in axial direction and filter supply that air to the filaments in radial direction, to

avoid fusing of filaments. The flow rate of air is equal in all directions to cancel the

opposite forces. The flow rate of this air is 1150 m3/hr. The purpose of humidification

is to enhance the rate of heat transfer as the specific heat of water is greater than

that of air.

Air Discharge

Air from each position is discharged at the base through a suction line that leads

the air at Scrabber.The temperature of this air is 60 C and flow rate is 1100 m3/hr.

PolymerMelt

Fiberformation

Quenchair

Ringoiler

Slubcatcher

Threadoiler

V-GuideSuctionNozzle

Cutter Drip

Detecter

DeflectiveRollers

FingerGuider

Dia BlowRoller

GodetRoller

SunflowerRoller

Sub Tow




83

This air is processed in scrabber where water is shavered on air that contaminate

the monomers and environment friendly air is discharged into the atmosphere.

Spin Wall Spin wall has following equipments with the stated functions:

Slub Catcher

Slub Catcher catches the thread coming out from the spinet.

Thread Oiler

Thread Oiler sprays the Spin Finish Oil on the threads coming from Slub Catcher.

The function of SF Oil is to reduce the static charge and enhance the cohesive

properties.

V-Guide

There is a V shaped guide that collects the filaments from the thread oiler. The

purpose of this is to create single tow of many filaments.

Suction Nozzle

Suction nozzle is there to facilitate the cutter. It sucks the filaments near the

effective part of cutter.

Cutter

After closing the filaments to the cutter with the help of suction nozzle. Cutter

cuts the filaments.

Drip Ejector

Drip ejector consist of two slides. These slides have a defined path for the

filaments between them. If a drip gets into it, it doesn’t allow the drip to pass. So

at the end filament gets break.










87

Four Fold Filter

These four fold filters have this arrangement on the basis of mesh size.

17000+4500+540+64

Five Fold Filter

These fivefold filters have this arrangement on the basis of mesh size.

17000+4500+540+64+4500

Ring Distribution Plate

Ring distribution plate is fitted just after the 5 fold filter.

Five Fold Filter

These fivefold filters have this arrangement on the basis of mesh size.

17000+4500+540+64+4500

Spinneret

1.

3750 holes(Circular)

2.

2250 holes(Trilobal)




88

Fiber Line Section

Creel Area The fiber line starts from the Creel Area till Cutter and Bailer. UDY cans are placed

in the creel area. Placement of the number of cans depend on the number of

working positions at spinning line. Number of working spin pack positions and

number of cans placed in the creel area are defined by over plant capacity; the

capacity to process a certain band of denier, for IFL-1 its value is ~3.2 Md (Mega

Denier). Mega Denier is defined by the width of crimper unit which, in fact, defines

the whole capacity of a particular draw line. For IFL-1, the width of crimper unitfor both the lines (71, 73) is 350 mm.

UDY from cans passes through tension adjustment equipment in the creel area. UDY or

sub-tow passes through following equipment during its journey:

1. Horn Guides

2.

H-Guides

3.

Knot Detector

4.

Loose end detector (uses photovoltaic detectors)

5.

Ring guides

Non-adjustment of tension results in poor product quality.

Finger Guides and Guiding RollersUDY enters into the fiber line draw zone after passing through finger guides which

guide the sub-tow towards the rollers in the later stages.

Tow guiding frame-1 (YO1) consists of seven rollers which adjusts the tension of

sub-tow and make it uniform for each filament of UDY. It is basically a 3-4

arrangement of rollers. Rollers are driven by a variable speed motor which adjusts

its revolutions according to the drawing speed.








91

Thermosetting Unit (Y10)Here the setting of all the thermal properties of polyester is carried out. Y10 has 12

rollers which revolve at variable speeds. There are actually three sets of rollers, four

in each set. Y10 is provided with 25 barg steam while pressure adjustment is

carried out in each set of rollers to achieve a specific temperature range to

achieve thermosetting of properties.

Rollers Temperature

1st set 190OC

Second set 191 OC

Third set 204 OC

Setting of following properties takes place in Y10:

1.

Tensile strength

2.

Denier

3.

Shrinkage

4.

Elongation

It is actually a thermal treatment process which does not infer any further

elongation in the fiber but maintains a high temperature and provides large

surface area for the properties to set.

TOW Cooler (Y11)It is a rapid cooling system which decreases the temperature from 205oC to 70oC

with the help of SF Oil which is showered at 50oC. Cooling results in the fixation of

polymer structure which had been set in the thermosetting unit.

Spin finish oil is sprinkled by 12 nozzles arranged at a 30 angle having 6 nozzles on

both sides.




92

Draw Frame-IV (Y12)The function of Y12 is to prevent shrinkages in tow. The frame has different

arrangement of rollers, i-e 4-3 (four rollers at top and three rollers at the bottom).

Unique roller arrangement facilitates tow converging and easy band formation.

TOW Converger and Three Roller Frame (Y13 & Y14)This unit overlaps the three tows used in the drawing & forms a single tow whose

width is comparable to the width of the crimper intake.

Tension Roller (Y15)The unit maintains the tension of the roller & again sent to the steam unit to gain

the cotton like property.

Pre-Steam Chamber (Steam Box Y16)This equipment finds its place before the crimper unit. It uses steam at 3 barg

pressure to heat tow band. If heating is not done then the crimpers will not form

permanently. Heating the tow will result in the formation of stable crimps.

Crimper Unit (Y17)Now tow is crossed through the crimper unit. This unit induces crimps on the fiber

at a rate of 13 crimps per inch. The crimps are made for necessary fiber flexibility

& cohesion with the natural fiber. Width of crimping section is 350mm.

Crimper thumb rule = 9350 denier/mm

Crimper width = 350 mm

= 3.2 Md




93

Traversing UnitThe tow leaves via traversing unit where spin finish oil is sprayed on the crimp tow

depending on the type of product. The traversing chute spreads the tow on the

tow drier plate.

Tow DrierIn this section the tow is dried & cooled. 10-bar steam is supplied for the heating

zone. After being dried the tow is transported to the cutter vertically to free roller.

Tow band temperature is reduced to ~52oC, drying takes place in four sections.

Fibre Cutter Unit (7458-Y23)After braking rollers tow has already attained much tension and it is passed to the

cutter. The cutter is a circular ring having blades of different sizes on edges. The

tow is passed through the pressure plate which presses the tow to wind around

the cutter ring. Due to winding the pressure on the inside increases and makes the

tow cut down according to the blade size. Once the tow has been cut it passes

down to the baler section.

CreelArea

Towguiding

Dippingpath

Drawframe 1

Drawbath

Drawframe 2

SteamBath

Drawframe 3

Thermosetting Unit

TowCooler

Drawframe 4

Overlapper

ThreeFrameRoller

Crimp unit Traveser

DryingUnit

Cutter Baler






95

A/C Section

A/C station is utilized for providing following types of air to the spinning and fiber

line:

Quench Air

Comfort Air

This station provides quench air to the spinning unit and comfort air for the

ventilation/ atmospheric temperature maintenance purpose in spinning and fiber

draw line plant.

Procedure:The fresh air from the atmosphere is sucked by K01 fan in the A/C station. Air while

entering the station passes the back filters to remove any suspended particles. On

the way to back filters the fresh air combines with the returned comfort air from

Cutter Pre-Bin Weigh-Bin

Pusher Pre-Press

RamRevolving

Unit

Main Ram Packing




96

plant, the returned comfort air is coming via K04 fan. Here the dampers are

placed. The dampers are there to decide the fresh air to return air ratio. It is done

in order to achieve the quench air temperature easily. After back filters is the

steam showering unit which only works if air has low temperature than 19-20Cusually in winters. The heat transfer coefficient of air is lesser than that of water.

That’s why air is being made humid to achieve better heat transfer. For this reason

there is showering of WC on air to make it humid. There is also a soft water filter

there in A/C unit which filters the soft water before being showered at the air

coming from back filters. Soft water showering is done to achieve 100% humid air.

Then further this humid air is passed through WCC coolers. WCC does heat transfer

with the humid air to achieve air at 19-20C. This quenched air is passed throughthe drift eliminators to remove excess water in order to achieve final 85% humid

air for quenching. Next this air is taken up by fans named K02 and K05 for the

quenching in spinning unit. Here one fan is stand by. And K03 takes away comfort

air for venting to the whole plant.







98

Single Filament Denier (d)

Single filament denier is the denier of a mono filament. It is observed in an

instrument called Vibroskop.

Position Denier (d)

Position Denier is the total denier of the number of filaments at each position.

= . . ∗ . ℎ

Tenacity (

⁄ )

Tenacity is defined as the ultimate (breaking) force of the yarn (in gram-force

units) divided by the denier. It is measured with an instrument called Vibrodyn.

We take one filament of UDY and place it in the machine. As the test starts, a

stress vs. strain graph is also plotted on the computer. A tensile force is applied

to the filament. The point just before which the filament breaks indicates the

tensile strength of the filament. It is calculated as:

=

Moisture (%)

Sample is weighed initially and then wrapped in a paper and placed in an

oven for 140˚C. After 30 minutes the sample is weighed again and the

difference in weight gives away the percent moisture.

OPU (%)

Oil Pick Up is the amount of oil, fiber can retain after being finished with spin

finish oil. In this test, we take 5g of UDY filaments in a burette and let 40g of

methanol run through it. Methanol absorbs the oil present with UDY. A flask is

placed below to collect the methanol and oil solution. It is heated to 100C,




99

methanol evaporates away and the amount of oil remaining is measured and

OPU is calculated.

Elongation (%)

The elongation at break is the increase of the length produced by stretching

a yarn to its breaking point. It is expressed as a percentage of its initial length. It

is examined via an instrument called Vibrodyn.

PSF

Denier (d)

Denier is defined as the 1 g per 9000meters fiber. It is examined using Vibroskop

in textile lab. A single fiber is clamped and then put it in the Vibroskop. The

vibroskop measures the denier and give digital results.

Tenacity (

⁄ )

Tenacity is defined as the ultimate (breaking) force of the fiber (in gram-force

units) divided by the denier. It is measured with an instrument called Vibrodyn.

We take one filament fiber and place it in the machine. As the test starts, a

stress vs. strain graph is also plotted on the computer. A tensile force is applied

to the filament. The point just before which the filament breaks indicates the

tensile strength of the filament. It is calculated as:

=

T-10 (

⁄ )

It is the tenacity of fiber at 10% elongation. It is calculated graphically from

the stress vs. strain graph obtained while measuring tenacity.




100

Elongation (%)

The elongation at break is the increase of the length produced by stretching

a yarn to its breaking point. It is expressed as a percentage of its initial length. It

is examined via an instrument called Vibrodyn.

Crimp Number (⁄ )

Mono fibers from different chips in sample are hanged via clamp one by one

on device and crimps are counted manually.

Crimp No. = 5.4

Crimp Removal (%)

Here one end of mono fiber from a chip in sample is stuck to a glass slab using

transparent tape initially. The other end is stretched until all crimps disappear

and stuck it too on the slab. Now the length is measured. Then via formula %

no. of crimps removed will be calculated.

Crimps Removed = − x 100

Crimp Stability (%)

Similarly % no. of crimps that stayed will also be calculated from this formula:

Crimps Stablized =−3

− x 100

Shrinkage (%)

In this test, 6-8 filaments from different chips in sample are collectively loaded

with a certain weight on shrinkage drum and readings are noted at shrinkage






102

Moisture (%)

Sample is weighed initially and then wrapped in a paper and placed in an

oven for 140˚C. After ̴30 minutes the sample is weighed again and the

difference in weight gives away the percent moisture.

Color Value

Color value of fiber is being checked by comparing it with a standard Cotton.

It’s a manual test. Two types of color values are checked, stated as follows

Color l – show whiteness

Color b – show yellowness

Bulk Density (

⁄ )

A can of measured volume is weighed initially W1. Then it is filled with sample

fiber without any force or weight. It is weighed again W2 and bulk density is

calculated as follows:

= 2 1






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