TEMPERATURE CONTROL DEVICE FOR RADIATION TUBE TYPE HEATING FURNACE

摘要

PURPOSE:To prevent the abnormal rise of waste gas temp. and to reduce fuel basic unit and production cost by providing respectively thermocouples in a waste gas passage and heating furnace and controlling the fuel flow rates in the first half heating period and the second half soaking period by means of a selecting switch. CONSTITUTION:The 1st thermocouple 7 is provided in a small duct 6 between the discharge side of radiation tubes 3 and a waste gas duct 5 and the 2nd thermocouple 8 is provided in a heating furnace. A signal selecting switch 18 selects the 1st thermocouple 7 by the command from a temp. monitor 19 while the temp. in the furnace is lower than the set temp. A temp. controller 9 inputted with the temp. detection signal from the 1st thermocouple 7 operates a fuel flow rate controller 10 to regulate the opening degree of a fuel flow rate regulating valve 12. The switch 18 selects the thermocouple 18 to input the detection signal thereof to the controller 9 thereby regulating the fuel flow rate in the time except the above-mentioned time.