Price ` 2/-Vol. XV December 2019 Price e 2/-

Er. Asok Kumar K FIE Er. K.K Gopalakrishnan Nair FIECHAIRMAN SpeAkS HoNoRARy SeCRetARy'S deSk

04.12.2019 Talk on ‘Spreadsheet Techniques Revolutionize Design of Electrical System of High Rise Residential Buildings’ by Er.A.G. Hareendralal, Director, Anantha Gangah Institute of Engineers, Trivandrum.7-13 December 2019: Winter 2019 iei Examinations11.12.2019: There will be no talk due to the AMIE Winter Examinations18.12.2019: Energy Conservation day Celebrations. Talk on 'Energy Efficiency and Renewable Energy' by Dr. R. Harikumar, Joint Director, Energy Management Centre- Kerala.

25.12.2019: There will be no technical talk due to Christmas.

Special AGM held on 01.12.2019 at Salem has approved the process of election to be conducted in the electronic mode. Hence, all members are requested update their contact details like mobile phone number and e-mail ID with HQ. May contact respective Local Centres or Kerala State Centre for any assistance.

The one day Colloquium "AGNI 2019" on "Space Systems Heat Transfer" was organised by IE(I) Kerala State Centre in association with the Indian Society for Heat & Mass Transfer Regional Centre Trivandrum (ISHMT RCT) on 23-11-2019.

The inaugural function was held between 9.30 a.m. and 11.00 a.m. The chief guest was Dr.V.K.Dadhwal, Director, Indian Institute of Space science & Technology (IIST). The function was chaired by Er.K.K.Gopalakrishnan Nair, Chairman - IE(I) Kerala State centre. Er. Asok Kumar K, Honorary Secretary, Kerala State Centre welcomed the guests and delegates. Dr.S.Sunil Kumar, Deputy Director- Liquid Propulsion Systems Centre (LPSC -ISRO) and also the President of the ISHMT - RCT explained objectives of the seminar. Er.Jagadeesa Chandra Pisharady, Member-Aerospace, IE(I) Kerala State Centre Committee proposed the vote of thanks. The seminar was inaugurated by Dr.Dadhwal by lighting the traditional lamp. 127 delegates consisting of practicing engineers from Liquid Propulsion Systems Centre (LPSC) and Vikram Sarabhai Space Centre

IEI SpEcIal aGM

VoIcE of KErala EnGInEErS

years of relentless journey towards engineering advancement for national building100

Last month we had a one day colloquium on ‘Space Systems Heat Transfer’ conducted at the State Centre in association with Indian Society for the Heat and Mass Transfer. It was very good function. The Engineering

Congress of this year will be held at Hyderabad on 27th, 28th

and 29th of December. The Thrissur Local Centre will host the National Convention of the Architecture Engineering Division on 7th and 8th of this month. Steps for conversion of all the elections of IEI into online process are progressing very fast. The amendments required for this in the bye-laws have been approved by the Council. Special General Body held at Salem on 1st December has approved the amendments. Hope that it will not only reduce the expense for conducting the elections but also will prevent any possibility for malpractice. The Mobile Number and E Mail Id of all members are required for the successful implementation of this. I request all members to update the membership register by incorporating these. The State Centre and the Local Centres are ready to render any help required. Wishing you all a Merry Christmas and a Happy New Year.

No.12

Merry ChristMas & happy New year

rEport on aGnI 2019

Voice of Kerala Engineers is being released only in electronic mode and members will receive them through e-mail/WhatsApp.

1Voice of Kerala Engineers December 2019

(VSSC) of the Indian Space Research Organisation (ISRO) as well as academicians and students from engineering colleges including IIST participated in the seminar.

The technical session included 6 talks, which were 1. 'Space Craft Systems and Missions": by Dr.Arun Kumar P,

Group Director, LPSC/ISRO.2. "Human Thermoregulation aspects in Space

environment" by Dr.S.R.Shine, Associate Professor, IIST.3. "Lean Automation": by Sri Sudhir Patankar, Managing

Director - PATSOL, Pune.4. "Thermal Challenges in Cryogenic Propulsion Systems":

by Dr.K.S.Biju Kumar, Group Head, LPSC/ISRO.5. "Tryst with tunnels". By Dr.B. Deependran, Group

Director & Project Director, VSSC, ISRO.

6. "Thermal and Humidity Control System of Crew Cabin for Human in Space Programme": by Sri.L.Aravindakshan Pillai, Group Head, VSSC/ISRO

After the technical session, panel discussion was held. The panelists were Er.K.K.Gopalakrishnan Nair-IEI, Er.S.Radhakrishnan-IEI, Dr.B.Deependran - ISRO, Er.Aravindakshan Pillai - ISRO, Dr.Bijukumar - ISRO, Dr.Prathap -IIST, Dr.M.Rajkumar - College of Engineering, Trivandrum (CET) and Dr.Jose Prakash, CET. During the validictory function, Dr.S.Sunil Kumar - ISRO summarised the deliberations. The valedictory function was chaired by Er.K.K.Gopalakrishnan Nair, Chairman - IE(I) Kerala State Centre. Dr.Jose Prakash, Vice President, ISHMT -RCT expressed the vote of thanks. The function concluded at 5.00 p.m. with the National Anthem.

GATE- A benchmark test for engineering graduates: Graduate Aptitude Test in Engineering (GATE) is an examination on the comprehensive understanding in various undergraduate subjects in Engineering/ Technology/Architecture and post-graduate level subjects in Science. It is conducted jointly by the Indian Institute of Science (IISc), Bangalore and the seven Indian Institutes of Technology (IITs). The examination would be purely a Computer Based Test (CBT)In India, the level of competition has exponentially increased in the past few years in GATE examination and the number of registration is crossing one million. GATE is very popular and significant especially in

B.tech + GatE – a Gold - Diamond companion *

engineering education sector and serve as a benchmark for normalisation of the Undergraduate Engineering Education in our Country. One can pursue Masters/ PhD/Direct PhD from IISc/IITs/NITs/IIITs/Central Universities with MHRD Scholarship through GATE. To emphasise that, the fortitude of GATE has extended the boundary of India and reaches to many developed countries. Some European union universities have set GATE scores as a criterion for their post-graduate and PhD admissions. Not only Corporate companies but also Government organisations are giving considerable importance to GATE qualified applicants in their job recruitment process. The number of PSUs using GATE score in their selection process is increasing every year and it might be crossing 100 in

Er. Shaji Jacob MIE, Former Technical Manager, SIEMENS, Norway & Member-IE(I) Kerala State Centre Committee

2 Voice of Kerala Engineers December 2019

coming years. Major PSUs using GATE score are Bharat Heavy Electricals Limited (BHEL), Gas Authority of India Limited (GAIL), Hindustan Aeronautics Limited (HAL), Indian Oil Corporation Limited (IOCL), National Thermal Power Corporation (NTPC), Nuclear Power Corporation of India Limited (NPCIL), Oil and Natural Gas Corporation (ONGC) and Power Grid Corporation of India (PGCI).

Direct recruitment to Group A level posts in Central government, i.e., Senior Field Officer (Tele), Senior Research Officer (Crypto) and Senior Research Officer (S&T) in Cabinet Secretariat, Government of India are now

being carried out on the basis of GATE score. The details of the scheme of recruitment are normally published in National Newspapers/ Employment News/ Rozgar Samachar by the concerned authority.

About GATE 2020: IIT Delhi is the organising institute for GATE 2020 and information website is http://gate.iitd.ac.in. Candidates have to register and fill the application at GOAPS online http://appsgate.iitd.ac.in. GATE 2020 examination will be held on February 1-2, February 8-9, 2020.

Under some conditions of low loads in the treatment plant, the contents of the aeration tank get nitrified and when it goes to the clarifier it gets de-nitrified and cause sludge floatation and escape of solids from the clarifier. A small upward flow tank will ensure a large stock of microorganisms which will denitrify the effluent before it enters the clarifier. In addition the provision gives stability of operation of the unit because the huge storage of aerobic microorganisms and protozoa in the unit.

The new design of Clarifier

Fig. 4. The new design of clarifier

Sometimes the recirculation ratio adopted for the return sludge in the extended aeration system could be high and may cause poor settling due to increase in hydraulic loading.

A new design of clarifier having two concentric compartments is made in which the inflow is admitted tangentially. The sludge settled will be drawn out at the bottom and the clear effluent is made to overflow and circular weir at the top. The design is shown in the Fig. 4. The advantage is that whatever the recirculation rate be, the increased flow will not affect the quiescent settling condition in the central chamber of the clarifier.

The design of the waste treatment plant. 300,000 l/ day of waste water from some residences and hostels are expected to be treated. The BOD is expected to be about 150 mg/l . After the screening and grit removal the waste water is led to a collecting tank (detention time more than a day) . A

Continued from August 2019 issue : Paper by Dr. N.Narayana Pillai

Evolution of A unique Extended Aeration ETP at Amrita University, Coimbatore*

The de-nitrification tank

pump ( Pump P1) of 2.2 KW is used to pump the water to the treatment plant. The scheme of treatment is shown in Fig. 5.

The aeration tank is of size 6m x 4 m and 4 m deep ( detention time 7.68 hours) . Pumps P2, P3 and P4 for aeration draw wastewater from the side of the tank and the delivery pipe is taken over the aeration tank. Sudden expansion aerating device of the same diameter as the delivery pipe is made and fitted about 1 m above the water level and then the pipe is taken down to discharge at the bottom. This made the pipes flow full and the discharge at the bottom caused thorough mixing inside the tank, air dispersed throughout and kept the solids in suspension.

There are many considerations for the selection of pumps for the aeration tank. The sudden expansion aerators require only very low head but high discharge. Pumps which work in high efficiency range are to be selected after studying the pump characteristics. In order to have a suitable pump , it is sometimes required to trim the blades, or use a motor having 6 or 8 poles so the speed can be lowered. The new discharge, head and power could be worked out by model laws for pumps. For final check, the head developed in the pump should be greater than the heads loss in the device. Also the oxygenation capacity provided by the aerators should be greater than the requirement to meet the BOD load .

Scheme of treatment by extended aeration

* Views expressed are that of the author

Voice of Kerala Engineers December 2019 3

Disclaimer: The Institution of Engineers (India), Kerala State Centre, as a body, accepts no responsibility for the statements made by individuals. Printed and published by Er. N. Rajkumar on behalf of The Institution of Engineers (India), Kerala State Centre. Printed at Akshara Offset, Kunnumpuram,

Thiruvananthapuram (Ph: 0471-2471174). Published at IEI-KSC, Visvesvaraya Bhavan, Opposite Kanakakunnu Palace, Thiruvananthapuram. Editor: Er.K. Ramanarayanan

ToIf undelivered please return to:

The Institution of Engineers (India)Kerala State CentreVisvesvaraya BhavanOpposite Kanakakunnu PalaceThiruvananthapuram - 695 033

Phone: 0471-2322991,0471 - 2982102, Fax: 0471 - 2322992 E-mail: ieitvm@gmail.com, keralasc@ieindia.org Web: www. ieitvm.org

Registered - Postal Regn. No.KL/TV(N)/536/2018-20

Licensed to post WPP No.KL/TV(N)/WPP/42/2018-20 at

TVM RMS Date of Publication : 07-12-2019

RNI No. KERENG/2005/22207

December 2019

Kerala State Centre- WEDNESDAY TALKS - Glimpses

I. Inflow waste B . detention tank A. Aeration tank D. De-nitrification tank E. Clarifier W. Waste sludge. F. final effluent . G. recirculation of sludge P1. pump for waste inflow

P2. P3. and P4 are pumps for aeration ( addl. Standby Pumps are also provided for aeration.). P5. Pump for recirculation of sludge.

The calculations are very much involved and are not reported here. Additional pumps are to be provided as standby units and also to adjust to variation in load. Two pumps of 7.5 HP, one pump of 5 HP and one of 3 HP are provided. In its actual working only 10.5 Hp was used on the average.

De-nitrification tank When the load is small, the contents of the aeration tank may get nitrified and when it goes to the clarifier the sludge may float and escape due to de-nitrification. To prevent that and to have stable effluent, a de-nitrification tank is interposed between the aeration tank and the clarifier. The tank is 2 m X 2 m size and 4 m deep (detention time nearly 1.3hours). The inlet to this tank is kept at the very bottom and the biomass content of the tank will be high above 8000 mg/l. As the wastewater flows upwards, it interacts with the contents of the tank and if de-nitrification takes place, the floating sludge will be broken and be overflowing the weir to the clarifier.

The clarifier : The clarifier was of special shape as explained earlier. It has two concentric compartments. The inflow is made tangentially at the outer channel and the settled sludge is withdrawn at the bottom. The effluent outflows from the centre of the central chamber. The volume provided is 37.5 m3 (detention time 3hours).

The treated effluent : The water, overflowing from the central outlet of the clarifier is led to a collection tank for storage. This is pumped out as and when required for watering the coconut farm. The effluent is very low in suspended solids and having low BOD and it is sparklingly clear and is devoid of any smell.

Discussions and Conclusions: The aerators were efficient and needed very little maintenance. The extra pumps provided allowed them to be operated in rotation. The biomass was well stocked with protozoa like Vorticella and rotifers. The new type of clarifier performed very well. The sludge was well settling (Sludge Volume index of nearly 80) and gave a stable treated sparklingly clear effluent which was odourless. The treatment unit is working well at the Amrita university campus for the past eight years. The power consumed was 0.62 kW.h. / 1000 litres of wastewater.

06.11.2019 Technical Talk on ‘Women in Engineering Entrepreneurship’ Er. Amritha Prasobh, Director & General Secretary, UKF College of Engineering & Technology, Parippally

13.11.2019 Technical Talk on ‘Role of Engineers in Project Viability Study’ by Er. N.Rajkumar, Past Chairman, IEI Kerala State Centre.

20.11.2019 Technical Talk on ‘Better Sustainable Growth- A lifestyle Change’ by Er. G. Aswini Kumar, Valuer & Civil Engineering Consultant.

27.11.2019 Talk on ‘Climate Resilient Green Infrastructure for Trivandrum City’ by Dr.E.Shaji, Professor, Department of Geology, University of Kerala, Kariyavattom, Thiruvananthapuram

30.11.2019 Special Technical Talk on ‘Emerging Trends in Battery Technology for Electric Vehicles’ by Er. K. Madhana Mohan, IRSEE, Dy. Chief Electrical Engineer, Railways. (Retd)

Special Technical Talk

* Views expressed are that of the author

4 Voice of Kerala Engineers December 2019