Patent ID: 6990966

Claim:
A heater unit for a combustion-stabilizing device a grounded heat-exchanger tube having more than one outer flat surface for mounting heaters, and having an inner surface to be in contact with a fluid to be heated; flat-plate heater elements provided on said more than one flat surface of said grounded heat-exchanger tube such that negative electrodes of said flat-plate heater elements are in contact with said more than one flat surface; insulating heater-holding member forming slit with said grounded heat-exchanger tube, said flat-plate heater elements being detachably inserted into the slit formed between said insulating heater-holding members and said grounded heat-exchanger tube; an electrode-holding member mounted outside said grounded heat-exchanger tube having said flat plate heater elements, for holding positive electrodes in contact with positive-electrode surfaces of said heater elements; and a grounded metal housing, wherein the assembly of said heat-exchanger tube having said heater elements and said electrode-holding member is inserted into said metal housing, said heat-exchanger tube and metal housing are electrically connected, and said insulating electrode-holding member prevents said positive electrodes held by said electrode-holding member from contacting with said metal housing and heat-exchanger tube.