HIGH-EFFICIENCY INFRARED ELECTRIC LIQUID-HEATER

摘要

An infrared electric liquid heater (10) includes a conduit (14) for carrying a liquid from an inlet to an outlet and an infrared radiant emitter (12) contained within the conduit (14) for heating the liquid carried in the conduit (14). The emitter (12) has a silica composition envelope (20) in direct contact with the liquid to be heated and an electrically heated filament (24) sealed within the envelope (20) for providing infrared energy through the envelope (20) into the liquid. The silica composition is drawn from a melt of 99.88 % to 99.94 % pure silica by volume, 0.04 % to 0.08 % crystalline sodium borax by volume, and 0.2 % to 0.04 % hydroxide of potassium by volume. The silica composition has sufficiently high structural strength to remain intact when contacted by cool water when the surface of the envelope is at or above 800 degrees F.