OPERATION METHOD OF PREHEATER FOR BLAST FURNACE GAS EXPANDER PLANT

• Main Authors: OGINO SATORU, TADAMA TOMOAKI, SOMA FUYUKI, SATO KUNIAKI
• Format: Patent
• Language: English
• Published: 25.04.2000
• Edition: 7
• Subjects: AIR INTAKES FOR JET-PROPULSION PLANTS; BLASTING; COMBUSTION APPARATUS; COMBUSTION ENGINES; COMBUSTION PROCESSES; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS; ENGINE PLANTS IN GENERAL; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES; GAS-TURBINE PLANTS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; REGULATING OR CONTROLLING COMBUSTION; STEAM ACCUMULATORS; STEAM ENGINE PLANTS; STEAM ENGINES; WEAPONS

PROBLEM TO BE SOLVED: To prevent a misfire and a backfire, and perform stable operation by recovering pressure energy of by-product gas, detecting a flow rate of the by-product gas, and controlling the flow rate so that a flow rate of combustion air becomes outside of a misfire danger range. SOLUTION: By-product gas coming out of a blast furnace 1 is cleaned by a wet dust collector 5 to be sent out to a turbine 2 after being heated by a preheater 200 so that the pressure energy is recovered as electric power. A flowmeter 301 is arranged on the inlet side of the preheater 200, a thermometer 302 is arranged on the turbine 2 inlet side, a flow control valve 303 for controlling a combustion air flow rate is arranged in a combustion air blow-in pipe 101 for blowing combustion air in the preheater 200 and a flowmeter 304 is arranged on the inlet side of the flow control valve 303. The flow control valve 303 is controlled by a controller 300, and the controller 300 controls the flow control valve 303 so that the combustion air flow rate becomes outside of a predetermined misfire danger range on the basis of signals from the flowmeters 301, 304 and the thermometer 302.