Abstract: This invention consists of a demountable heat recovery device, which can turn any tube into an efficient heat recovery, for applications in fire tube liquid heaters and steam boilers; the present heat recovery device is comprised by a tube, which may be cylindrical or square, inside which a gas diffuser is placed having a transversal cylindrical, pentagonal, hexagonal, octagonal or square shape, and the most important is that the cavity formed between the fire tube and the gas diffuser shall be narrow, of at least 0.001 m, and that the combustion gases shall flow at high speed, of at least 6 m/sec through said narrow cavity; since only in this way a great amount of heat is transferred to the inner wall of the fire tube; according to this invention, high thermal efficiency heaters and boilers can be built and with a less number of tubes, wherein a mechanical blower has to be installed for them to operate.

Abstract: A water heater having improved efficiency. The water heater includes a tubular member that is mounted in an opening in the side of the tank and extends generally horizontally across the tank. The tubular member defines a combustion chamber and a fuel burner is located within the combustion chamber. The outer end of the tubular member communicates with the atmosphere and air is drawn into the tubular member and mixed with fuel to provide a mixture which is ignited. The waste gases of combustion are discharged from the inner end of the tubular member into a heat exchanger which is located in the tank beneath the tubular member, and the hot waste gases being discharged from the combustion chamber and passing through the heat exchanger transfer heat to the water in the tank. The heat exchanger is connected to a stack and a blower is mounted in the stack downstream of the heat exchanger and serves to draw the waste gases of combustion from the combustion chamber through the heat exchanger to the stack.

Abstract: A water heater having improved efficiency. The water heater includes a tubular member that is mounted in an opening in the side of the tank and extends generally horizontally across the tank. The tubular member defines a combustion chamber and a fuel burner is located within the combustion chamber. The outer end of the tubular member communicates with the atmosphere and air is drawn into the tubular member and mixed with fuel to provide a mixture which is ignited. The waste gases of combustion are discharged from the inner end of the tubular member into a heat exchanger which is located in the tank beneath the tubular member, and the hot waste gases being discharged from the combustion chamber and passing through the heat exchanger transfer heat to the water in the tank. The heat exchanger is connected to a stack and a blower is mounted in the stack downstream of the heat exchanger and serves to draw the waste gases of combustion from the combustion chamber through the heat exchanger to the stack.

Abstract: A method for operating a heating plant having a boiler with a heat exchanger following the combustion chamber, such that it can be operated continuously and the exhaust gas temperature maintained at a predetermined value, in which a continuously controllable burner is employed and the effective heat exchanger area is adapted to the burner output.

Abstract: A water heater having improved efficiency. The water heater includes a tubular member that is mounted in an opening in the side of the tank and extends generally horizontally across the tank. The tubular member defines a combustion chamber and a fuel burner is located within the combustion chamber. The outer end of the tubular member communicates with the atmosphere and air is drawn into the tubular member and mixed with fuel to provide a mixture which is ignited. The waste gases of combustion are discharged from the inner end of the tubular member into a heat exchanger which is located in the tank beneath the tubular member, and the hot waste gases being discharged from the combustion chamber and passing through the heat exchanger transfer heat to the water in the tank. The heat exchanger is connected to a stack and a blower is mounted in the stack downstream of the heat exchanger and serves to draw the waste gases of combustion from the combustion chamber through the heat exchanger to the stack.