Patent ID: 6858824

Claim:
A microwave heating system using a heat conductive medium comprising: a heater including: a shell forming an enclosure having an upper end and a lower end; a heating coil located in the enclosure, the heater coil having an upper end and a lower end and having an inverted frusto-conical shape, the upper end of the coil being larger than the lower end; three magnetrons mounted adjacent the heating coil, one magnetron being located at the upper end of the heating coil and the other two magnetrons being located on opposite sides of the heating coil for directing microwave energy into the heating coil; an electrical distribution system connected to the magnetron; an electrical distribution system connected to the magnetron; a return line for supplying the heat conductive medium into the heater coil adjacent the lower end of the shell; a line means connected to the heating coil toward the upper end of the enclosure and extending outside the shell, the line means having two branches; a domestic hot water water heater including: a first heat exchanger, at least one medium tube located in the first heat exhancer, one branch of the line means being connected to the medium tube and the medium tube also being connected to the return line, at least one water tube located in the first heat exchanger, a plurality of fins extending across both the medium tube and the water tube to conduct heat from the medium tube to the water tube, a second heat exchanger, a water coil located in the second heat exchanger, the water tube being connected to the water coil at both ends; and heat exchanger means connected to the other branch of line means to receive heat conductive medium and being connected to the return line; and a circulator located in the return line.