Monday, January 24, 2011

Performance Gurantee Test - Salem 2 Hi mill,

In the last post I wrote a story which was not exactly my own experience but experience of one of my colleague in the section Mr JVSN Rao. I desire to dedicate one posts on my old colleagues of  80's in MECON - particularly when Rolling Mill and Auxiliary Equipment Division (RM&AED) of MECON was located in rented building called Apna Bazar Building - which houses Income Tax office now. RM&AED also was called United Wing due since we used to design and supply rolling mills under collaboration with Wean United Inc of Pittsburgh, USA. There was one company's who's brochure meant for Mr BP Sarkar used to have an interesting address

"Mr BP Sarkar, Chief Design Engineer,
United King, MECON, Ranchi-834002".

Replacement of United Wing with "United King" matched well with Mr Sarkar's royal manners and we shall some time refer to Mr Sarkar as "UNITED KING" Our department was headed by Mr Ramadurai. Others were Mr BP Goyal, Mr SM Ganguly, Mr JVSN Rao and Mr Kalyan Bhattacharjee. Myself, Mr SB Mukherjee and Mr Manoranjan Danpart joined in 1978 as per parallel transfer from another SAIL unit namely Bokaro Steel. I shall detail out this later. Now for main story of today.

Story  about Performance Guarantee  test at Salem.
Me, Mr Vidyanathan, Mr Raha, Dr Pandey etc constituted MECON's team  for PG Test in 1987. .During pre checking of Mill readiness, Salem engineers desired to change 2nd short dump from 80 mm to 105 mm. This was needed to accommodate  roll protection unit which had lost its shape due to wrong force cylinder operation earlier and now needed 105 mm gap.

In absence of Siemens Germany's engineer, BHEL didnot want to touch AGC panel. As usual for my inquisitiveness, I studied to drawings and found that one BCD (Binary Coded Decimal)  register when converted read 8000. I quickly came to a conclusion that this must be 80 mm short dump reference and thought to change this. The change needed only  shorting for the zeros one ones, so as to read 10500 or more. Dr Pandey was anxious the moment he knew what I was up to. He tried to convince me to let the status quo remain. How ever I being in different department than his, stood ground and explained, in case the changes did not work, I can revert back the settings. I could set to nearest to 10530 and we got a short dump of 105.3 mm. I knew, I have won the hearts of operators of Salem as this change was very important to them. Operators were key for us to pass through the PG test and I desired to keep them in good humor. One operator named Quadir - a Malyali guy was an excellent operator and a good friend of MECONIANS. He later went to middle east. Another trainee operator had terrific accident when manually polishing the rolls and his hand went inside the roll gap - it took six months for him to again get back to work.

Null Setting of  servo valve of Hydraulic roll force  cylinders was another contentious issue , I had already done this setting along with Sri CND Nair,  for safe and equal dumping movements of both cylinders at approx 4% of flow in case of power failure,  and I did not want proposal department to recheck this. I did not cooperate in terms of help from BHEL they needed and it was impossible for them to do anything themselves in Salem. They had taken more than required credit of this insignificant electro-hydraulic related thing in past in Rourkela and I did not want this to happen in Salem. In MOM with Salem Steel it was recorded "Servo valve's null setting was done by MECON during commissioning (ie in 1980), however this may checked by plant once every month".

In the night of PG test there was lot of drinks - Whisky specifically,  available at site and we all were drunk. However I had noticed slippage of strip on deflector rolls particularly at high speed some time resulting on negative elongation measurement. For MECON to pass nobody should notice this in the displays. I decided to be behind the panel for the whole night correcting the factor thumb wheel switches for the 2 deflector rolls such that elongation for the major portion of strip reads within the set value and so MECON was successful in passing one of the first PG test of the mill. Mechanical guys will not agree that the strip was slipping on the deflector rolls and design should have been different for Stainless Steel. I tried to prove my point through publications and calculations though in vain. I am sure they still do not agree with me in the same way they thought regarding the dump valves was erroneously getting energized by Electrical Circuits till proven wrong.. (this story also for a later post..).

Mr Kalyan Bhattacharjee has requested me to publish the story of Ms Silk Smitha - Tamil Danseuse and actress staying in the same hotel very near to my room. I shall post this and other story regarding we almost missing the flight in the very next post... very very soon..

Sunday, January 23, 2011

Midhani - Mr Rana and Mr BP Sarker..

In the last post I have posted regarding problem of heavy foundation vibrations of Entty Reel due to faulty instrument gearing arrangement and and how EPC was commissioned. In this post I am going to write a brief story I heard from my friend Sri JVSN Rao as reminded by my friend Sri Kalyan Bhattacharjee regarding visit of Mr BP Sarkar to Midhani, Hyderabad. In subsequent post I am also going to tell a story as to how low on money, we almost missed our flight back from Madras to Calcutta (that time it was neither Chennai nor Kolkata).

Firstly story at MIDHANI.
Mr JVSN Rao was posted on temporary transfer to Midhani, Hyderabad for commissioning of bar mill. That time temporary transfer meant allowance of  Rs 13.00 a day against Rs 54.00 per day for persons on tour. Since engineers from all other department were on tour, Mr Rao used for feel deprived. When invited by Mr Rana for beer, he used to calculate his finances since a bottle of beer used to cost Rs 17.00. During that period. Mr BP Sarkar visited Midhani. and as usual was behind some panel during a late afternoon. Mr Rana who didnot recognize Mr BP Sarkar and may have taken him as a junior engineer though he was Engineering Manager and even senior to Mr Munshi, Rana's boss. In a hurry to go back in the evening Rana patted Mr Sarkar on back and said in Hindi " hume bhi koochh batoa thora electrical main bhi janata hoon. Aab band karo chalo kahi beer sheer pitain hain cabret sabret dekhte hain". Mr Sarkar didnot clarify the position he gave him just a cold look. Rana realised his mistake during the same trip when Mr Munshi clarified to him that Mr Sarkar is even senior to him. Rana could not get chance even to apologise to Mr Sarkar.

other part of story in next post.....

Friday, January 14, 2011

2 Hi Stainless Mill at Salem, By MECON, Edge Guiding System etc.

Hope you may have read my earlier posts, I am awaiting more and more comments. This post is regarding edge guiding system by GPE provided by MECON with electrical controls- meaning there by BHEL's scope was limited to one feeder in MCC.

As told in earlier blogs, BHEL was main electrical supplier and their 4-5 engineers were posted at Site for commissioning. I was a guiding engineer from MECON, since MECON was involved on overall design and we knew complete project from incoming power supply to end connections. From Panel and transformer locations to cable route to main and aux motors and motor and ECR ventilation. BHEL had experts of converters and power systems. While I had taken over MCC commissioning including building of logics as per our functional descriptions, when it came to Edge Guiding system controls, BHEL threw tantrums that this is not in their scope and they will not commission it. I though of commissioning it my self. I had 7 year of  hands on commissioning experience while at Bokaro Steel (SAIL) and had commissioned large units alone such as 5 units in Sinter Plant-1 (Screening unit, Crusher plant, coal storage and handling, large Synch Motors, mid section of Sinter Bed-1), MSDS2& 5, Roughing section of HSM - 5x 10 MW motors, Pickling Line, CRCF etc & this was a small thing to do. I was however little apprehensive regarding support from Head Office, since such direct commissioning work was not attempted by MECON earlier. I found electronics for GPE was simple using photo sensors to detect edge and generate a positive or negative reference depending upon whether photo cell was covered by strip or not. This will move the POR to or away of the mill till the light was just half covered. Simple. Only adjustment was sensitivity and speed of movement for a given error. I had already commissioned manual part of cylinder movement and GPE controls only needed to be activated using blocking valves of main hydraulic circuit. This commissioning enhanced my image with Salem Steel operation personnel who started approaching me for any modification they needed for equipment controls. I also obliged by modifying circuits for problems like creeping of walking beam's long travel cylinder.

Later due to use of contamination prone aux Hydraulic system B for GPE, the servo valve started malfunctioning and myself was sent along with Mr Narshihman of Lube section of MECON to rectify. Similarly CO2 fire fighting system from M/s Vijay Fire also was not functioning. The system was a turnkey supply by M/s Vijay Fire and several visits by them did not resolve the problem fully. 

Mr Narsihman was totally at loss to understand the edge guiding system's hydraulic circuit. He was not sure why a blocking valve was provided and why there were "left" and "right" movement valves in addition to GPE valves. How he opened the servo valve despite warnings in GPE's literature and thus spoiled the servo  action and how Sri TR Rao tried to salvage the situation in our next visit to Salem will be detailed out in the next blog on the issue. Please read on as to how we had spent all money we had during PG test and we were about to miss our flight back to Calcultta (that is how it was pronounced then) due to a problem in Madras or Sennai (as written at the airport in Tamil even when not officially renamed.

Wednesday, January 12, 2011

Salem 2 Hi Mill by MECON - Visit of Mr BP Sarkar

I have put in this blog some technical and one semi technical story, hope you shall still read on.

We 3 engineers from MECON - my self, Sri TV Vaidyanathan and Sri CND Nair had some times some relief in the form of engineers sent for small durations of 10 to 15 days. While Sri TV Vaidyanathan has relievers like M/s PC Sahu, Mr J Sahu from Ranchi and Subrata Bhaumik from Kolkata office. For Sri CND Nair, Sri SDR Kumar and Sri DD Sinha came as relievers. For me it was Sri SM Ganguly, who use to come over for approx 7-10 days after I did approx 45 days - maximum number of days not requiring Director's approval those days. During one of the overlap time with Sri SM Ganguly, we had a problem during commissioning of payoff reel. After it was optimised by BHEL, during running and particularly during speed changes, there were terrific vibrations in foundation as if the motor will break the foundation. After few trails BHEL lifted their hand. During site discussions Mr SM Ganguly observed that there must be some problem with tacho feed back and we tried at first to locate any ca ble screening problem. I remember having dreamt one day regarding Ohio instrument gearing and it came to my mind that the play in gearing may be playing havoc with the system. Since the KB6 tacho system was very light, the gears play was resulting in un called for vibrations. BHEL did not agree, Result we used a hand kerchief as brake at tacho coupling to create small load on the gears and it dampened the vibrations to a large extent. The foundation were not shaken and our theory was accepted. Result removal of Ohio gears for direct connection of tacho to main gears.Since gearing were needed only to match reels RPM with those of tacho for wrap counting,  this actioin disabled the wrap counters for both reels completely and automatic slow down after a defined wraps  never were commissioned. Mill runs like this even today !

We were informed about Mr BP Sarkar's visit one day and I  was required to bring him from the station. I went there with our taxi car and received him. His very fist question was did you start rolling in the mill? Since I had improvised roll force cylinder lifting using battery box, and even rolled, I said "yes". He said "Tab hum kya karenga?" This answer remained a matter of joy to me and to my colleagues. He however was furious when he found how we rolled. He started scolding me for putting the mill to peril by rolling without load cells. I could nor argue with him regarding using relief valve to limit the roll force. He made us run around to adjust speeds of all hydraulic cylinders as per design and Sri CND Nair was sore going up and down to cellar. His next step was to fix tensiometer which had broken bearings. Since he went inside mill housing which was full of grease, we also went inside and spoiled our clothes and shoes. He tried to fix load cells also and spent whole day behind the panel. When ASEA tensiometer and load cells could not be fixed with his clear offer of a good dinner to all BHEL engineers, he agreed to witness rolling using batteries as we did earlier. However he did nor like 100 T load and asked us to increase it to 200 T. We did as instructed. This however resulted in un-controlled reduction of material on the two sides and thus in skew. The material will this move to one side and fold up in the reels. Whole day we did not succeed in stable rolling. Only when Mr Sarker left site we changed back to 100 T force for sucessful mock rolling to be shown to the minister later on.. 

Next re-commissioning of GPE system and visits of Mr TR Rao, Mr Narshihman and failure of fire fighting panels,

Tuesday, January 4, 2011

Salem 2 Hi mill -AGC Cylinder Commissioning for Minister's Visit

Hope you may have gone through my last post and enjoyed how I sent Mr DD Sinha to ladies toilet due to my ability to read Tamil but having poor vocabulary or how we gave lift to Mr Raju ED, Salem Plant in our brand new Taxi Car and enjoyed no checks at gate for next one month !! In this post I want to be little technical. Being far away from HO we had little or no interference from MECON's Ranchi Head Office and we did as we liked. There were no phone let alone mobile phone those days. Communication was through telexes or difficult to get trunk calls. We had 3 visits by Mr Subimal Ghosh then Chief Design Engineer, One visit each by Mr BP Sarkar then Chief Engineer, Mr BC Mondal, then GM and Mr PC Laha then Director - only 6 visits in about 9 months, we were at Salem all most at a stretch.
We were trying to commission the mill as fast as possible and most of the motors and hydraulic system were commissioned. Unlike earlier practice where MECON's electrical engineer will only stand or see BHEL commission the plant, I went ahead to do some hands on commissioning, which started due to a tiff with BHEL regarding scope of edge control commissioning (I will tell the story in next post). BHEL engineers at site Mr Kumar and  Mr Pillai agreed to provide me with instruments and one helper. Mr Sambasivam another BHEL engineer and In charge was a man who always read through contracts and was a difficult person.
NOW  to main story of today -- AGC system control were supplied by Siemens Germany and a German Engineer was to arrive to commission it. It was getting delayed since ASEA's load cell, Tensiometer etc were not ready due to faulty power supply. In the mean while there was a visit by Mr ND  Tiwary. then Minister for Steel. We were asked to run the mill with strip in the mill. Now this was not possible without Hydraulic Cylinder of the mill lifted from bottom to at least touch the strip. Here came my earlier exp at Bokaro handy, where we used to give reference from a battery box for UBCR (Op Amp) ckts. Moog valves were to take about 20 mA each coil for fully open the valve. I decided to connect them in parallel and pass 40 mA using battery box. Later we improvised and used  V/I converter of Simatic C3 modules to pass 40 mA and opened both side moog valves. Pressure of Hydr System C was adjusted using relief valve to a value to generate roughly 100 T of load and the cylinder lifted to touch the strip. We successfully rolled MS coil with paper winders / unwinders in use and no body could know that in fact mill is far from commissioning.. Next story visit of Mr Sarkar..