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pp 2 of ~ The Shaffer furnace was not in service during my visit. It was down for refractory repairs and replacement. The propane burner is rated at 3 MM ETU/hr. The average propane consumption is 30 ~ph which results in burner heat release of 2.75 MM BTU/hr. The recovered aluminum requires approximately 840,000 BTU/hr, the scrap iron al'proxima%ely 110,000 BTU/hr and the heat loss was estimated et 100,000 BTU/hr resulting in a net difference of approximately 1.S5 MM BTU/hr discharged from th£ furnace with the burner at maximum rate. PARTICULATE REMOVAL The existing water spray is an inefficient method of removing particulates from a flue gas stream. The existing stack from your reverberatory furnace was observed to be clear. However, since a charge of dirty scrap could result in stack emissions, our recommendation is to install a baghouse filter to remove the particulates that can be generated from your recovery process. A baghouse installation requires an infiuent gas stream that is a~bove the dew point to prevent wetting of the filter bags. We therefore recommend that the water sprays be removed from the Shaffer Furnace and that the flue ~ases be coo!e~ by air dilution to attain the proper baghouse inlet temperatures of from 250 to 300 F. During the summer,the cooling air required to lower the baghouse inlet temperature to 300 F is ~00 SCFM with the furnace burner operatln~ at its rated capacity of 3 F~ BTU/hr. The products of combustion from the propane are 510 SCFM resulting in a total required gas flow of ~9i0 SCFM or 13,000 CFM at 300 F. A portion of the cooling air enters the system via the hood above ~he furnace. The balance of the air required ~il! De introduced to ~he suction of the blower through a damper inlet valve. Th~ flue gas ~_e~ o.~ ~ exDec~_~ to be low by our field observations. A filter ba~ cas ratio to square area w~!l be approximately 9:1 resulting in a baghouse sizin~ of approximately 1500 Ft The process involves aluminum which classifies as a light metal. Therafora, the baghouse must be ~ns~¢~led ~ ~ outdoors and away f~, the bu_=~g in order to be "~*~ the fire codes.