Demonstration of Energy Conservation Measures under PCRA Project
* Furnace and Insulation Design:The Council designed the furnace with proper emphasis on the functions of three different zones – preheating, combustion and soaking zones. The furnace was properly insulated by designing the optimum thickness and adopting the best specifications and material. As a result, the industry has been able to achieve consistently a production with considerable savings in fuel consumption and reduced heat losses.
LBR insulation on furnace Insulation for inspection & material discharge door
* Pulverizer :The Council analyzed the problems inherent in the existing pulverizers and got the pulverizer modified by increasing the hardness of the material, choosing proper alloys and also through re-engineering in terms of number of hammers and size of hammers and the speed of the drive system. Earlier results of pulverization, as got tested from a reputed lab, had revealed that hardly 1-15 % of the coal could be pulverized finer than 200 mesh, but with improved design and materials, we could pulverize the coal to the fineness of 75 micron, 60-80% of which passing through 200 mesh. It has resulted in better combustion which was at once visible through the color of the flame, faster combustion rates and distinctly lower scale losses.
Conventional welded MS liner & New EN 31 grooved liner Grooves in EN 31 Liner
Conventional welded MS Hammers Casted Mn Alloys Hammers
* Burners :Earlier the burners were not designed and a simple pipe 4” dia was used as burner for feeding coal mixed with air into the furnace. The burner has now been designed with proper arrangements both for primary and secondary air and also the arrangements are made for providing air at the proper pressures. This has gone in a big way in improving the combustion and control over the percentage of excess air which has now been restricted to less than 20%.
Conventional hollow pipe used as burner without provision of secondary air Burner with provision of mixing of primary & secondary air for complete combustion
* Recuperator :Presently, none of the re-rolling mills is preheating the combustion due to unsuccessful designs of the recuperators tried by the industry so far. The Council analyzed that primarily these recuperators were loaded underground and no maintenance was carried out. The pipes were never cleaned periodically. The expansion joints were not provided for. The pipes of the recuperator, therefore, got warped out and the recuperator used to get defunct. All these defects were removed in new design which was laid above ground with proper expansion joints and with arrangements for regular cleaning of the pipe. It has been possible to preheat the combustion air to a temperature of 250oC resulting in improvement in the combustion process and reduction in coal consumption.
Conventional Recuperator (shell & tube type) placed underground New designed of recuperator (shell & shell type) placed over ground
* Instrumentation :Interaction was carried out with a number of instrumentation experts to design the instrumentation system with inbuilt provisions for control of air with the temperature in the furnace. The best possible instrumentation has been procured inform of variable frequency drive (VFD), thermo couples, temperature controller etc. As a result, the industry has been able to regulate the volume of combustion air and its pressure in the reheating furnaces with the resulting reduction in scale losses and wastage of fuel.
VFD to control air of blowers Thermocouples to monitor furnace temperature