Soldering of heat exchangers made of heavy metal or steel - in forced air circulation furnace used to ensure uniform heating of exchangers during soldering

摘要

Hot air is circulated in the most favourable direction through the heat exchanger; and the air temp. is measured on both the inlet and exit sides of the heat exchanger. The measurements are used to control the heating time, holding time, and cooling time of the exchangers during the soldering or brazing operation. The pref. furnace includes one or more heating chambers contg. thermocouples located above and below the heat exchanger(s) and used to control a burner or electric heater for the air, and/or the speed of a fan circulating the air in the furnace. The forced streams of air travel through the pipes and/or cavities of the heat exchangers so all parts of the latter attain a uniform, specified temp.