Image Number 3 for United States Patent #7935882.
A self-powered food heater. The food heater includes a burner with an electric fuel pump and an electric blower, a fire box, a water tank and electronic controls. The food heater also includes a set of thermoelectric modules compressed against a heat transfer surface of the tank. Hot exhaust leaving the burner enters the fire box. Some of the heat from the fire box passes through the thermoelectric modules generating sufficient electric power to power the fuel pump and the blower. Water in the tank is heated to its boiling temperature. Heat from the boiling water heats food also contained in the tank. In a preferred embodiment special compression frames provide substantially uniform compression, within desired ranges, of the modules between a portion of the heat transfer surface of the tank and a module cover plate. Fins may be provided on the cover plate or insulating spacers may be added to assure the hot side temperatures of the modules are within desired ranges to provide desired power output without damaging the modules. In a preferred embodiment the modules are compressed against a heat transfer surface on the outside of the tank within the fire box.