OVERHEATING DETECTOR FOR ROTARY REGENERATIVE HEAT EXCHANGER

摘要

PURPOSE:To accomplish an accurate detection of abnormal temperature rise regardless of operation temperature by continuously comparing the operation temperature with the reference temperature for a fixed period. CONSTITUTION:This overheating detector is composed of a temperature detecting cylinder 40 incorporating a thermocouple 4 provided close to the heat transferring device 1 in a hot gas outlet 21 of an air preheater and a warning device 41 comprising a reference temperature memorizing circuit 42 and a warning generating circuit 43. In operation, voltage generated by the thermocouple is applied to a comparator 45 as detection voltage through a milli-volt/volt converter 45 while done to the comparator 46 as the reference voltage through a sampling electronic switch 48 controlled with a timer 47 and a hold circuit 49 whereby the detection voltage is continually compared with the reference voltage. When the detection voltage exceeds the reference voltage, it is judged that a fire is occurring and a buzzer is actuated.