BHEL’s first 2 x 660 supercritical boilers for National Thermal Power Corporation’s Barh project in Bihar will go through chemical cleaning shortly.
Chemical cleaning completely removes oxides of iron through passivation, a technique involving application of a light coating of material to create a shell against corrosion. The inner surfaces of the heat transfer tubes are thereby protected from corrosion and other damages.
As a preparatory exercise, a two-day workshop on ‘Chemical Aspects of Once-through Supercritical Boiler Cleaning’ was initiated at BHEL, Tiruchi, on Friday. Engineers will gain hands-on experience in actual conduct of chemical cleaning of super critical boilers.
The workshop was of high significance against this backdrop, S. Sundararajan, General Manager, Research and Development and Coal Research, said in his inaugural address. Chemical cleaning practices for super-critical boilers vis-à-vis sub-critical boilers were different.
Chemical cleaning in sub critical boilers was done when the boilers were firing, while in super-critical boilers, cleaning was done at a lower temperature and without firing when chemical additions were made. Waste chemical should also be properly handled, he said.
R. Easwaran, General Manager, Welding Research Institute and Labs, suggested that chemical cleaning and boiler chemistry be dealt with as a multi-disciplinary science for best results.
Mr. Sundararajan handed over the first copy of the proceedings to B.K. Roy, Additional General Manager, Power Sector, Northern Region, BHEL Noida.
General Managers M. Palanivel (Human Resource), V. Vasudevan (Planning and Development, Modernisation and Civil), S. Ramesh (Advanced Technological Product), and S. Krishnamoorthy (Marketing and Proposals) addressed participants.