FROST DETECTOR FOR REFRIGERATION SYSTEM

摘要

A frost detector for an air-cooling refrigeration system having an evaporator coil mounted in a main airflow duct is comprised of a first bypass duct connected to the main duct on each side of the coil and a second reference bypass duct connected to each side of a constriction in the outlet side of the main duct downstream from the coil. Signals from airflow velocity sensing devices in each bypass duct are compared to provide a defrost initiation signal to the refrigeration apparatus and the preferred airflow velocity sensing device is an air-cooled electrical resistor connected in a bridge circuit.