High pressure liq. cleaner - has electric heating elements between pressure source and cleaning jet

摘要

High pressure cleaning fluid, e.g. water, is supplied to a cleaning lance. A servo-controlled valve regulates the fluid flow to the latter while an electric heater (11) heats the fluid to the optimum cleaning temp. The heating element (13) consists of semiconductor platelets pref. based on silicon and held between alumina substrates. The platelets are metallised on each side for electric contact and are thermally bonded to the alumina substrates to serve as a diode or simple semiconductor path. The space between the substrates is sealed with a solder ring (17). A temp. sensing diode can be incorporated inside the heater. ADVANTAGE - Compact heater, high heating rates; less cleaning chemicals required at higher temperatures.