THAT LIVELY MEMORY STILL BECKONS

I am not talking about any victorious achievement. It is an exciting moment in my life which will be ever memorable for me. It was my visit to the NALCO Captive Power Plant in Angul, one of the biggest power plants in India. There what I saw and learned was really stunning and invigorating. I had decided to catch something adventurous in this plant because I might not be able to do in future until luck favours and the entry pass was valid up to one month. My training period was scheduled by the training officer. It was a month duration. I had been accompanied by my six friends. We got astounding support from the senior managers, chief managers and training officers from the very first day. They lauded us for being ITERians... really. That conducive atmosphere triggered my enthusiasm to a peak. Let me describe my experience there briefly.
The plant is divided into 10 units with two units under construction now. The output of each unit is 120 MW. So the net output now is 960 MW. Nalco has targeted for 1200MW in near future. Nalco is connected with Talcher coal mines with rails. Coal is transported by trains and dumped in large coal yards. Then it is transported to the furnace through large conveyor belts with many intermediate processes. The coal yards are controlled and maintained by coal handling plants (CHPs).A data shows that around 1000 tonne coal is transported per hour by the conveyor belts.
Water is supplied to the plant with huge pipes from the Brahmani River, 14 kms from here. It is stored in large reservoirs and are supplied to the boiler after being purified and then demineralised by chemical processes. The most surprising thing was the boiler. It stands 30 meters from the ground level. Here the water is steamed and is supplied to the turbines. The boiler is heated strongly by the furnace situated just below it where powdered coal is burnt. Our training guide very carefully opened a small slot and showed us the flame. While looking at the flame from 2 metre distance, I felt as if my whole body was fumed. Everywhere there was dust and the area was sounding vigorously. But unfortunately we did not use safety helmets and ear plugs.
Now the generation part...The construction of every unit is same in first six units and some changes have been made in other units. The turbines, generator and exciter are connected with a single large shaft. The generators actually generate power. Each turbo generator has a capacity of more than 120MW with 10.5 KV and running with 3000 rpm and more. The generators are hydrogen cooled in first six units and air cooled in 7th and 8th units which are newly constructed. Since hydrogen makes an explosive mixture with air, the temperature and pressure are maintained very carefully and its leakage prevented by seal oil system. The generator is of 7-8 metres long and nearly 6 feet tall. The exciter is there which provides a magnetic medium for the mechanical energy to convert into electrical energy. Nalco has first implemented brushless excitation system.
The steam that comes through pipes into turbines is superheated, no water containt. The steam is passed through the turbines and they rotate. The turbines, turbo generator and exciter are connected through a single shaft. The steam is recycled by cooling it in the huge condenser. In condenser the cold treatment of steam is done by cold water from cooling water pump house (CWPH).The condenser pipe is of such a big diameter that even a Maruti 800 car can pass through it! Water is again fed to the boiler by a boiler feed pump (BFP) which is of 3.6 MW capacity. The pipe pressure is checked automatically by actuators fitted at required places.
Each unit has two transformers. The 10.5 KV output from the turbo generators is the stepped up to 220 KV by the generating transformer and is taken to the switch yard where it is then supplied to the smelter plant which is about 4-5 kms away from CPP. The 10.5 KV is also stepped down to 6.6 KV by unit auxiliary transformer which is supplied to the units where it is used to run motors, pumps and other equipments. The 220 KV is also stepped down to 6.6 KV by station auxiliary transformers to run cooling water pump house, coal handling plants and demineralising water plants etc. Nalco sells its surplus power to GRIDCO. It also provides power to the Nalco Township. The whole unit looks like a nexus. So many pipes, so many interconnections!!Wow! It is really mind-boggling. Each unit has a control room which controls and maintains it. It is no longer manual and is replaced by sophisticated controlling instruments with the advent of technology. The relay systems are fitted at in circuits and other places to check any malfunctioning there. They send signals to the control rooms and accordingly action is taken immediately. Besides there are ash slurry pump houses, cooling water pump houses, switch yards and other parts of a plant.
The flora inside the plant really tempted me. Large acres of land were looking majestic with afforestation. The eco-friendly environment reduces the surrounding temperature and pollution to a large extent. Nalco has adopted TPM (Total productive maintenance) policy for an upbeat pursuit towards its organisational excellence. It is quite interesting that even during this economic turmoil, Nalco has a thumping Q3 net profit of over 219 cr for year 2009.
I came across the most embarrassing thing in Nalco CPP. On the walls of a small shop it was written “Smoking here is an offence”. But many workers and technicians were smoking there freely feeling that smoking there is a pleasure. Also there is no restriction of selling cigarettes! Even some technicians were smoking inside the elevator in the technical building. The Nalco authority should take a strict action against those culprits. It is totally excruciating that even in such big and plants where a small fire can take many lives and spell a big national loss, rules are openly breached. Also the security provided by CISF (Central Industrial Security Force) personnel is just an eyewash. They don’t check properly the vehicles going inside and at any time a terror attack is possible. The Govt should consider this issue seriously, implement a rigorous security system and beef up the surveillance.

Largest Ever Breach in Shield That Protects from Sun’s Violent Blasts

Recent satellite observations have revealed that the largest breach yet seen in the magnetic field that protects Earth from most of the sun’s violent blasts, reaches reported.

The discovery made last summer by Themis-a fleet of five small NASA satellites was reported by experts on Tuesday (16^th Dec 2008).

Scientists have long known that the Earth’s magnetic field which guards against severe space weather are similar to a drafty old house that’s sometimes lets in violent eruptions of charged particles from the sun.

Such a breach can cause brilliant auroras or disrupt satellite and ground communications. Observations from Themis show that the Earth’s magnetic field occasionally develops two cracks, allowing solar wind-a stream of charged particles spewing from the Sun at 1 million mph-to penetrate the Earth’s upper atmosphere.

Later summer, Themis calculated a layer of solar particles to be at least 4000 miles thick in the outer most part of Earth’s magnetosphere, the largest tear of protective shield found so far.” It was growing rather fast,”Themis scientist Marit Oieroset of University of California, Berkely told to an American Geophysical Union meeting in San Francisco.

Such breaches are temporary and the one observed last year lasted about an hour, Oieroset said. Solar flares are a potential danger to astronauts in orbit but generally are not a risk to people on the surface of Earth.

Scientists initially believed the greatest solar breach occurred when the Earth’s and Sun’s magnetic field are pointed in opposite directions. But data from Themis found that the opposite to be true. Twenty times more solar wind passed into the Earth’s protective shield when the magnetic fields are aligned, Oieroset said.

The Themis results could have baring on how scientists predict the severity of solar storms and their effect on power grids, airline, military communications and satellite signals.
COURTESY:The Associated Press(AP)