Patent ID: 6188047
Filing Date: 2001-02-13
Classification: H05B

Abstract:
A radiant electric heater comprising a metal dish containing a base layer of thermal and electrical insulation material, a metal heat shield interposed between said insulation material and said metal dish and a resistance heating element physically supported by said insulation material, said insulation material comprising a solid porous mass of fused silica particulates formed in situ in the metal dish, said fused silica particulates having an average particle size up to about 100 mesh United States screen size and with non-porous characteristic being formed by void spaces between the fused silica particulates, and with said solid porous mass of fused silica particulates having been formed by first preparing a foamed liquid suspension of the fused silica particulates with a non-gaseous surfactant type foaming agent then converting the foamed liquid suspension to a gel condition and finally removing liquid from the converted gel mass of fused silica particulates after having been deposited in the metal dish.