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Show Variac 115 vac x 25 w /) Voltmeter 115 to 300 vac transformer with one side of silicon steel plates taken away and with a water-cooling jacket Fig. A Modified Transformer For the Detection of Iron Accumulation V. CONCLUSION Through this study it is clear that the irons in coal and coal ash are mostly in the pyritic form. A small part of pyrites is thermally dissociated and reacts with oxygen to form Fe?0 which is then partially reduced to free iron. Therefore only a small amount of iron in coal ahses is in the form of free iron. There are two possible ways to solve the problem. One way is to convert pyrites to Fe 0 in small particles and they are to be carried away by exhaust gas as flying ash. The other way is to keep the slag in a molten state and to let them flow out of the exit hole on the floor. The first way has been tried at Tampa Electric Co. with moderate success. Additional modification to eliminate the downward momentum of the coal particles is proposed to improve the situation. In the second method, the slag temperature of 3000°F is to be brought up by burning additional coal particles on the furnace floor and by stoichiometric combustion of coal near the floor. No major modification is needed. Through the study of instruments, it i;. proposed that Lnfarad gas analyzers are used for the detection ol gas composition, tungsten-tungsten rhenium thermocouples for the temperature measurements and a modified transformer for the detection of iron accumulation. Furthermore, the iron in coal ash has a great potential to become 8 |