Internship Report 2011 ALL 2003

INTERNSHIP REPORT 2011

Internship Report 2011

Khairpur plant Kallar kahar, Chakwal

Usman Hussain Malik (2008-NUST-BEE-423) 1Electronics Engineering SEECS-NUST, Islamabad


Prepared by :

USMAN HUSSAIN MALIK

Reg No # :

2008-NUST-BEE-423

DEPARTMENT OF ELECTRONICS ENGINEERING,

SCHOOL OF ELECTRICAL ENGINEERING AND

COMPUTER SCIENCES

NATIONAL UNIVERSITY OF SCIENCES AND TECHNOLOGYISLAMABAD



:: Table Of Contents ::

1. Introduction …………………………………………………………………. 062. Block diagram of factory …………………………………………………… 073. Power plant …………………………………………………………………. 084. Steps of production …………………………………………………………. 08

a. Limestone crusher ……………………………………………….…… 09b. Storage yard ………………………………………………………… 09c. Stacker …………………………………………………………………. 10d. Raw mill feed area and raw mill ……………………………………. 10e. Coal storage area and coal mill ……………………………………… 11f. CF silo …………………………………..…………………………… 12g. Rotary kiln, kiln motors clinker silo ………………………………… 13h. Clinker silo ……………………………………..…………………... 13i. Cement mill feed area ……………………………………………….. 14j. Cement mill and cement silo ………………….……………………... 14k. Packing plant ………………………………………………………… 16

5. Laboratories ………………………………………………………………. 16 6. PLC ………………………………………………..…………………….. 167. Future trends of plant ……………………………………….……………. 178. References ………………………………………….…………………….. 189. Conclusion ……………………………..…………………………........... 18



ACKNOWLEDGEMENT:

In doing this internship, I would firstly thank ALLAH Almighty who blessed me with the ability and potential to complete it well and good. Before writing down what I learnt during my internship, I would like to add a few deepest words and also says thanks for the people who were part of this report in numerous ways. While preparing for the internship and going out in the field to gain adequate knowledge and going as deep as I could to collect maximum amount of information, there are several people who deserve to be notified and mentioned for provided me help.

Out of these guiding people in particular, I would like to thank the managerial staff at DG Cement especially Mr. Safdar Kamal, Mr. Hafiz Sajid and Mr. Sarfaraz Ahmad. They became the source for me to have the wonderful opportunity to do internship here and gave me chance to improve my industrial skills that will surely help me in the practical field. They helped me to gain a lot of information regarding the company and cement industry and also who provide me an opportunity to learn and understand the working of organization as an internee. I would also say thanks to Mr. Babar who guided me during the internship and briefed about the various electrical instruments are being used here in the plant. Along with them, Mr. Ghulam Rasul of E&I workshop and Mr. Amir of 811 sub-station are also worthy to be mentioned and thanked.

Finally, I would thank the team of DG khan Cement Company limited and its Chairman, Mr. Mian Muhammad Mansha in particular.



EXECUTIVE SUMMARY:

Dera Ghazi Khan Cement Company Limited Khair Pur Plant a unit of NISHAT group is a strategic business unit of Nishat Group, which is the largest and most growing industrial group in Pakistan. D.G. Khan Cement Co. is market leader with respect to market share with about 11.4%. Apart from its competitors, its product is relatively high priced yet it has highest market share because of good quality. That is the reason why it is producing most of the cement needed in the country as compared to other cement companies. Its plant is situated in Dera Ghazi Khan and Khair Pur and head office is situated at Lahore. All the plants are situated in places where the raw materials needed are all at one place.

Among these plants, two are located in DG Khan while one in Khair pur near Kallar Kahar. This one is installed with the collaboration of a Danish company called FLS. Much of its machinery is imported from Germany clearly showing that it has high-tech machines running and gives it a clear upper edge on the competitors. This plant has a total production capacity of 6700 TPD. Currently the company is also exporting the cement to various countries like Iraq, India, Afghanistan and UAE. D.G Khan Cement has also contract with ELEPHANT cement at SriLanka.

To the big machinery running here, the power needed to keep it running is also massive. Total power being provided to this plant is 32.3 MW to energize this massive mechanical setup.

The fuel consumption is also a matter of concern and new ways to reduce or minimize the fuel consumption is under the attention. The proof of this is the newly created RDF plant where various pollutants scattered all around are brought and baked to produce heat that is sent to the kiln along with the conventional fuel being used. This is also a significant and intelligent way of reducing the pollution from the environment.

In addition with this, there is also a paper mill running here for the purpose of producing plastic bags to be supplied to the packing plant. A total of 1.6 million bags are being produced for this purpose. They not only suffice the packing requirements in the plant itself but are also sold to the neighbor contemporaries.



1. Introduction:

Nishat group is one of the most renowned business groups in Pakistan. It was founded by Mian Muhammad Mansha in 1951. It is playing a significant role in the private sector by adding value to cotton and the cotton based economy. Nishat Group ranks among the top five business houses in Pakistan terms of sales and assets. The company has fixed/current assets of over Rs.300 billion (US$ 5 billion), it ranks amongst the top five business houses of Pakistan and has a strong presence in textiles, cement and financial services, as well as a market share in insurance, power generation, paper products and aviation.

Nishat Mills Limited started out as a weaving unit with 500 semi automatic looms, later on 10,000 spindles were added, laying the foundation of nation’s biggest textile composite project. Today, Nishat Mills Limited is largest vertically integrated unit of Pakistan. It comprises of 270,000 spindles, 740 state of the art shuttles-less and air jet looms, a processing capacity of three million meters and stitching capacity of more than one million meters per month, supported by a power generation plant with a capacity of 33.6 MW.

D.G. Khan Cement Company Limited (DGKCC), a unit of Nishat group, is the largest cement-manufacturing unit in Pakistan with a production capacity of 5,500 tons clinker per day. It has a countrywide distribution network and its products are preferred on projects of national repute both locally and internationally due to the unparallel and consistent quality. As discussed earlier, the premium quality of the cement produced by this very company is due to the state of the art machinery imported from abroad. It is listed on all the Stock Exchanges of Pakistan. Furthermore, DG Khan cement company`s plant near Kallar Kahar production line of 6,700 TPD clinker, the single largest production line in the country.



2. Block diagram of the process:

The block diagram shown below is useful for the reader to take a glance at. This will greatly increase the level of ease to learn all the process easily. Each block below shows the steps:

Limestone/ Clay

Crusher


Gypsum crusherClinker SiloRotary Kiln

Coal mill and RDF

CF silo

Cement mill

Storage yard Stacker

Raw mill

Packing plant


3. Power Plant:

For continuous and smooth operations of the plant uninterrupted power supply is very crucial. The power is supplied to the huge machinery with the help of;

a) Two grids from WAPDA of 132kW power.b) Two transformers in the power station producing 632 kW power.

The company has its own power generation plant along with WAPDA supply. The power provided by WAPDA is converted to 632 kW by the step down transformer. The Company power plant consists of two Generators, these are dual nature generators that can be run on GAS as well as on Diesel depends upon availability of fuel. In case if any of supporting engine fails to work the company has Turbine Engine of CATERPILLARS so that there is no load shedding at all. The two generators combine produce 32.2MV of energy one generator produce 16.1MV and other one also of 16.1MV. Maintenance of generators is made by staff of WARTSILLA.

These transformers are then connected to all the panels in the sub-stations. This connection is based on the bus topology that is a common bus of wires is running from where more wires branch out and supply power to panels of the required ratings. There are total of thirteen panels of thirteen substations.Details of the transformers deployed to power up the machinery are;

PEL IEC-76


PARAMETER QUANTITY

Type of coupling ONAN

KVA 1600

Frequency 50 Hz

Volts (HV) 6300

Volts (LV) 415

Amperes (HV) 146.63

Amperes (LV) 2275.93

Phases (HV) 3

Phases (LV) 3

Impedance volts 8%

PARAMETER QUANTITY

Oil Liters 1489

Weight of oil 1312 KG

Total weight 4612 KGYear of manufacture 2005

Switch position 1 6615 H.T Volts

Switch position 2 6457.5 H.T Volts






MOTORS:

Motors of the following power are being used mainly;

LOCATION POWER

Limestone Crusher 1540 kWCement mill 3400 kWRaw mill suction fan 5100 kWRaw mill main motor 3400 kWCooling fan motors 237 kWID fans 1800 kW

4. Steps of production:

There are certain steps in which the manufacturing of cement can be divided. These steps, along with the details are narrated one after the other below.

a. Quarry:

Quarry is the place from where raw material in extracted. The technique used to extract the raw material is by drilling first and then blasting. A hole of about 10-15 m is drilled and ammonium nitrate in filled as an explosive in these holes. When this explosive is ignited the rocks are broken into pieces of different sizes. These pieces are then loaded on the dumper trucks of Caterpillar Company and using conveyor belt to the crusher. It is located about 3-4 Km from the plant. The raw material used is;

I. Clay as it contains silicon in abundance.


INTERNSHIP REPORT 2011 II. Silicon is the main material used in the production of cement. It is to be used along

with limestone to produce cement. There is 25% contribution of silicon in cement. They are dumped into large dumps after extraction from the rocks.

2. Limestone: The major contribution in the cement is of limestone. It constitutes 95% of the total. It is cruicial to provide strenght. This limestone is extracted by nearby Quarry and has the highest composition in cement.

3. Additives: The additives maily contain Bauxite, Nitirte, iron and Gypsum (5%). They can be considered as accessories and they are meant for additional quality of cement as well as being the catalysts.

b. Limestone/Clay crusher:

The limestone crusher, supplied by FL Smidth has capacity of 1500 tons/hour. Limestone is dumped into hopper firstly. Inside the crusher machine hammers having an average weight of 101 kg crushes the big indigenous stones .

In crusher, the Squirral Cage Induction motors are used to rotate the hammers and rotatry speed of motors is 1200 to 1300 rpm. The motor responcible for grinding is of 1540 Kw. Terminal box vibration monitor regulates and limites the vibration of huge motors.The crushed material is sent to suction bags where dust is sucked and re-used while the other crushed material is conveyed by conveyor belts to the storage yard. To deal with the magnetic particles, iron separator is used which is a magnet and thus separates out the ferric material out there.

c. Storage yard :

The function of storage yard is to store the crushed material is stored in the form of piles in the

storage yard. There are 6 piles in the storage yard. Characteristics of all piles in storage yard are

given as follows;

2 Mixed piles of limestone & clay

2 High grade pure limestone

Iron ore additive


INTERNSHIP REPORT 2011 Bauxite additive

Besides, there are four hoppers, each containing the material listed above respectively.

d. Stacker : A stacker makes conical piles of the crushed material. Feed from storage yard is conveyed to the stacker through conveyor belts. This stacker then moves to and fro to make a pile. Now, for conveying this material from piles to the conveyor following equipment used is as follows: Side scrapper: Picks the crushed feed from the piles through its feed belt called Hoist. Reclaimer Used to throw feed down from the pile and has two arms called harrows.

e. Raw mill feed area and raw mill:

The raw mill feed area has of 4 feed hoppers:

Mixed feed hopper

Pure limestone hopper

Bauxite hopper

Iron ore hopper

The capacity of first two hoppers is 800 tons while the other two hoppers have a capacity of 600 tons. The feed from each pile is conveyed to the hoppers through conveyor belts in relevant hoppers. Each hopper has 4 load cells. The feed is controlled by load cells that sense the quantity of feed being loaded into hoppers. Separation of iron pieces is also assured.

The raw mill have total capacity of 500 tons/hour and the motors that are used in raw mill are induction motors and have power of 4.3 kW supplier of motors are FL Smidth . There are three sections of raw mill that are described as follows;

I. Table with three rollers:

The raw feed from the belt conveyor falls on the rotating table of the raw mill. The table contains three crushing rollers. The raw fed is crushed to fine powder with these rollers. Relatively bigger particles are collected at the bottom of raw mill and are recycled for re-crushing.

II. Bottom scrapper:At the top of the raw mill, there is separator section. A suction fan with motor power of 4500 kW produces suction and sends dusty air into the cyclones at the top. Here the dusty air rotates

around a fixed axis causing particles to get separated from the air. These particles are collected at the bottom of the cyclone and sent to the CF silo with the help of air slides.


INTERNSHIP REPORT 2011 III. Separator:

In the next stage, hot gases from the kiln come from the bottom of the raw mill and lift very fine particles with it. A suction fan with motor power of 4500 kW produces suction and sends dusty air into the cyclones at the top. To separate the air from the dust, air rotates and particles are separated from the air. These particles are collected at the bottom of the cyclone and sent to the CF silo with the help of air slides.

The air still contains some dust and to ensure that maximum amount of dust has been received, conditioning tower is the place where this air is sent to sprinkle water on it and in this way, dust (cement) gets separated.

f. Coal storage area and coal mill:

Coal yard is the area where coal is stored which is used as fuel in baking the powered raw materials to produce cement clinker. There are different piles for the storage of local and imported coal. Coal is thrown on a sieved net by handler to separate bigger pieces of coal and stones form it, before it goes to the tunnel. From the tunnels the coal is placed on the belt conveyor which takes it to the coal mill feed area.

Then comes the stage of coal mill feed area. After the impurities are removed from the coal, it is chatted on the belt conveyor .A bag filter is employed which sucks the coal dust and thus prevents the coal from being wasted. The coal is then shifted to the coal storage hoppers. Magnetic separated caters for the iron pieces in coal. There are three hoppers for storing coal each with the capacity of 250 tons.

Coal mill: now is the stage of coal mill. Coal mill at DG Khan cement has capacity of 52 tons/hour in case of mixed coal and 26 tons/hour in case of pet coal.

The total capacity of motors used in coal mill are 600kW.Process in the coal mill is nearly the same as in raw mill.



g. CF silo:

Coming back to the raw mill where we have powered raw material, it is sent to the CF or continuous flow silo with the help of bucket elevator. The CF silo is of;

Capacity = 25,500 tons

Length = 54 meters

Diameter = 22.4 meters

The next stage would be pre heater. Low bin in the CF silo takes the material to the air slides. Before that, air is circulated in silo in such a way to throw the material to low big which can hold maximum of 118 tons.

Cyclone pre heaters:There are total 10 cyclone pre heaters. Five are on the right side of the pre calciner and 5 on the left of the pre calciner. Purpose is to heat the material before sending it to kiln for final baking.

Firstly, the material is sent on the top of second cyclone. The hot gases from the kiln flow with very high speed and lift the particles to the top of the 1sr cyclone.

Then the material falls on the top of the 3rd cyclone and sends it into the 2nd cyclone. Then the material falls on the top of 4th cyclone and hot gases take it into the 3rd cyclone. Then the material falls on the top of the 5th cyclone and hot gases take it into the 4 th cyclone and finally into the 5th cyclone pre heater.

Gas analyzer:In gas analyser, which is actually part of pre heaters, there are basically three cylinders which have CO2,O2 and S02 respectively in each cylinder. Three analyser machines are used manufactured by ABB are used. Main purpose of this gas analyser is to clean the gases before sending them to the kiln for burning process and for cleaning the gases we send NH2 nitrogen into cylinders one by one to obtain zero numeric value for each gas so that gas is free from dust etc and safe to send to kiln. Three analyser machines are used manufactured by ABB are used.



h. Rotary kiln, kiln motors clinker silo:

Physical parameters and details of Kiln:

It is the most important part of cement maufacturing process as

materials are baked here to produce cement.

The kiln has length of 66 meters, diameter of 5.5 meters. its

rotatry speed depends upon the. In case of relatively larger feed,

kiln will rotate faster and similarly its slow rotation would indicate

less quantity of feed. Inner part of kiln has refractory type and

provides insulation to outer environment with the help lining of

bricks inside it. Outside material also protects the envoirment.

Arround the kiln, there are induced draft fans that sense

temperature and if temperature rises from a limit the fans will

turns on automatically to ensure security to outer environment,

otherwise, they will remain off.

There are two motors, one on each side of the kiln. These motors have reasonably high torque to

accomplish the purpose of rotating this massive shaft. It moves with the speed of 2.5 rpm

usually.

The very hot material from kiln falls into kiln hood which has an angular sieve,when material passes through the kiln hood it becomes clinker and now this clinker will be sent to the clinker cooler.

Clinker cooler:Clinker cooler is used to lower the temperature of Clinker. The Induction fans suck air from atmosphere and send it to clinker cooler and the conveyor belt at the bottom takes this cool clinker and send it to the clinker crusher.A suction fan is installed which sucks the product dust from the cooler and send it to the electrostatic precipitator where dust is removed and clean air is exhausted to the atmosphere through a chimney.


INTERNSHIP REPORT 2011 When the cool clinker falls into clinker crusher then the big stones of clinker are crushed into small pieces and this material now send to the clicker silo.

i. Clinker silo:

Clinker silo is 60 m high and its width is 46 m. There are 3 gates at the bottom of the clinker storage from where the clinker is the clinker from the deep pan conveyor is stored in the clinker storage. Its capacity is 110,000 tons. Its length is sent to cement mill through belt conveyor. Besides the main clinker storage bin, there is a temporary clinker storage hopper with a capacity of 1400 tons. If the temporary hopper is also full then the clinker is

removed from the hopper and dumped into clinker storage yard.

j. Cement mill feed area, cement mill and cement silo:

There are two cement mills at the plant and there are total six hoppers in cement mills, three in each mill in feed area.The 1st hopper contains the clinker which is major constituent of the cement. The cement contains 95 % clinker which is conveyed through weigh feeder to the main belt conveyor which takes it to the cement mill. Remaining 5% material is gypsum and additive material. The mixing of these materials takes place here. The crushed gypsum from a separate crusher is conveyed by belt conveyor to the cement mill. It is mixed in the clinker while crushing. Gypsum is added to about 5 %. Its purpose is to increase the settling time of the cement. The additive which is pure limestone is also added in the cement mill, about 2% to increase strength of cement. Now cement is in the final stages and therefore its purity is ensured. This is done by using metal detector to check if there is any left iron impurity or not. Other sensors detect the presence of stones etc.



Cement mills: There are two cement mills at the plant and each of them has

capacity of 175 tons/hour.

The motors that are used in cement mills are of 4300KW of

power and manufactured by FLSmidth.

The feed which is free from impurities falls on the table of cement

mill which contains three rollers. Each roller has weight of 35 tons

and the clearance between table and rollers is 0.5 mm. These

rollers move hydraulically using nitrogen gas as hydraulic fluid.

The rollers crush the feed to a very fine powder. Then the air slides

convey the ground product to the bucket elevator which lifts it to

enter into the 1st storage silo.

Cement storage Silo:

There are three cement storage silos in which crushed cement is

stored until packing. To convey the cement to the other 2 silos air

slides are used. From these silos the cement enters air slides by air

circulations through blowers. Now these air slides take the cement

to the packing plant.

Capacity of storage silos is 21,000 tons, length is 45 meters and

diameter is 22.4 meters.



k. Packing plant:

The packing plant comprises of six packers and 12 terminals. Each packer has a capacity of 100 tons/hr. The cement bags are attached manually to the rotating packer which fills the cement bag. When the bag is filled up to the required weight, it automatically falls on the conveyor belt which takes the bags to the roller conveyor. From these rollers the bags slide to different channels and finally cement bags are loaded on the trucks for dispatch.

Weight Bridge:

Every truck or loader of cement that comes out from packing plant have to go for weight if the weight exceed than a limit loader will be turned back for accuracy, so weight bridge also plays an important role. The average weight of each bag is 50 ± 1.5 kg; otherwise sensors being deployed recycle the bag back.

5. Laboratories:

There are following laboratories for the purpose of testing, checking and regulating composition of material under process at various stages. So these are necessary to ensure quality material at all stages.

1. Sample preparation Lab: Checks samples of material used in kiln.2. Press Mill: Pressure exerted of 150 KN on dye which have material.3. X-ray Analysis: X-ray analysis check determine the composition.4. Chemical testing lab: It determines the time of consuming process.5. Physical testing lab: Determine strength of cement samples.

6. PLC:

Programmable Logic Control (PLC) is the main controlling area of the plant. So this is the most

important and critical part of the whole plant as each and every process depends on this.

Plant is controlled by CCR (Computerized Control Room) which have different

sections like IT Dept., Exchange, Laboratories, Control Room, and PLC. PLC Dept. have to look

after that while every component in plant is working properly or not if there will be any fault


INTERNSHIP REPORT 2011 according to Automation they have to remove that. Plant has ten major PLC’s main

controlling PLC port is of SEIMENS Co Ltd. Signals send to control room by underground

wiring of cable Fiber optics also used for long distances.

7. Future trends of plant:

Examining the current state of art technology and nearly fully automatic control system, one can easily accept that the future of this plant seems bright. Automatic Control:

The overhead of man-power and demanding work of monitoring each and every thing is not only difficult but also hectic tasks and more error-prone. This manual labor is replaced by automatic control through electronics and programming techniques. PLC serves the purpose of monitoring, regulating and alarming in case of deviations.

Reliable long communication:PLC has to communicate and interact with the various devices and plants as well as CCR. To make sure that the communication is reliable, fiber optics is being used for this purpose.

RDF plant:

Refused Derived Fuel (RDF) is the under construction project partly and partly it is working at DG Cement Plant.RDF indirectly will clean the city from garbage all the garbage from nearby cities will bring to RDF and a crusher which using a squirrel cage low starting torque producer cuts-off the garbage

into small pieces that will be conveyed by conveyor belts to storage yard and from there it will be cleaned from stones and metallic materials using same technology as discussed before in cement mills. From pre-heaters this garbage will be thrown into kiln for burning purposes. RDF have 6 motors that I have seen during my stay in DG Cement these all are squirrel cage motors that will move the conveyor belts and each motor have 4300KW of power.



8. References:

www.google.com

www.wikipedia.com

www.sick.com/.../cement/Pages/cement.aspx

www.siamrefractory.com/cement_cyclone.php

www.lwbref.de/en/markets/cement-lime-industry/

9. Conclusion:

I would bring this report to end by concluding my experience in the industry. It was my first ever

industrial tour and this was a great experience. Learning each and every thing from books is a

good thing but going out in field is a whole new thing. This is a crucial thing and it teaches how

to interact with colleagues and above all, one comes to know how the field is like. I gain lot of

knowledge about industries that will be helpful for me in future. Being an engineer I simply got a

direction for my future by this internship.

Finally I would like to thanks all staff of DG Cement Khairpur plant for their

help and guidance. Every person at factory site tried to help the way he could in every possible

way.

I would be more than happy to work was internee with them if I get the chance of it.

Usman Hussain Malik

2008-NUST-BEE-423

SEECS-NUST, ISLAMABAD


http://www.lwbref.de/en/markets/cement-lime-industry/

http://www.siamrefractory.com/cement_cyclone.php

http://www.sick.com/group/EN/home/solutions/industries/cement/Pages/cement.aspx

http://www.google.com/

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