Patent ID: 6872072

Claim:
A radiant heating unit comprising: (a) a supply for providing a quantity of fuel in vapor form at a predetermined pressure; (b) means to mix air into said fuel to produce a combustible fuel/air mixture; (c) a housing having a periphery surrounding an open bottom; (d) a removable and replaceable cartridge being affixed to said periphery, said cartridge covering said open bottom, with a skirt extending downward beyond said cartridge, said housing and said cartridge defining a chamber, said cartridge separating said chamber from ambient air; (e) said chamber being connected to receive said fuel/air mixture; (f) said cartridge being removable from and replaceable in said housing, said cartridge containing multiple layers of non-flammable materials that are bound together into one unit by a border which surrounds a periphery of said layers, said layers being porous enough to allow said fuel/air mixture to pass through said layers but sufficiently dense to prevent large amounts of ambient air from entering said chamber through said cartridge so that combustion occurs at an outer surface of an outermost layer.