Abstract: A combustion gas furnace includes a plurality of primary heat exchangers for passage of combustion gases therethrough. A plurality of secondary heat exchangers receive the combustion gases from the primary heat exchanger. Each of the secondary heat exchangers includes a heat conductive element defining a plurality of elongate passageways for the flow of combustion gas therethrough. The passageways include aligned ports at either end thereof. The passageways are generally aligned and separated by longitudinal walls extending between the ends. The walls are positioned for heat conductive contact with the combustion gases flowing through passageways.

Abstract: A shield for placement around burner ports in a hot air furnace for reducing turbulence in the flow of secondary combustion air entering a heat exchanger. The shield also provides for intercepting moisture that condenses along the walls of the vertically oriented heat exchanger. The heat exchanger is part of a furnace. The drip shield includes a plate having a longitudinal axis and a plurality of through-openings placed in the plate along and/or parallel to its longitudinal axis. The through-openings are spaced apart so as to be positioned between and aligned with burner ports and respective heat exchanger tube inlets of the heat exchanger. The plate is preferably profiled to have a peak to encourage condensate run-off with the plurality of through-openings being placed along or generally parallel to the peak of the plate.

Abstract: A combustion gas furnace includes a plurality of primary heat exchangers for passage of combustion gases therethrough. A plurality of secondary heat exchangers receive the combustion gases from the primary heat exchanger. Each of the secondary heat exchangers includes a heat conductive element defining a plurality of elongate passageways for the flow of combustion gas therethrough. The passageways include aligned ports at either end thereof. The passageways are generally aligned and separated by longitudinal walls extending between the ends. The walls are positioned for heat conductive contact with the combustion gases flowing through passageways.

Abstract: A clamshell heat exchanger comprises upper and lower clamshell plates assembled together and sealed at the peripheral edges thereof, the assembled plates defining at least three internal passageways communicating in a serpentine configuration. The passageways include an inlet passageway having an inlet port for receipt therethrough of combustion gases, an intermediate passageway and an exhaust passageway having an exit port for the discharge of combustion gases, all such passageways lying generally parallel to each other. In one arrangement of the heat exchanger, the upper and lower clamshell plates define an air gap between the inlet passageway and the intermediate passageway, with the intermediate passageway and the exhaust passageway being joined by a secured flattened portion of the upper and lower clamshell plates. In another arrangement, instead of an air gap, the inlet passageway and the intermediate passageway are also joined by secured flattened portions of the upper and lower clamshell plates.

Abstract: A clamshell heat exchanger comprises upper and lower clamshell plates assembled together and sealed at the peripheral edges thereof, the assembled plates defining at least three internal passageways communicating in a serpentine configuration. The passageways include an inlet passageway having an inlet port for receipt therethrough of combustion gases, an intermediate passageway and an exhaust passageway having an exit port for the discharge of combustion gases, all such passageways lying generally parallel to each other. In one arrangement of the heat exchanger, the upper and lower clamshell plates define an air gap between the inlet passageway and the intermediate passageway, with the intermediate passageway and the exhaust passageway being joined by a secured flattened portion of the upper and lower clamshell plates. In another arrangement, instead of an air gap, the inlet passageway and the intermediate passageway are also joined by secured flattened portions of the upper and lower clamshell plates.

Abstract: A tubular heat exchanger for an infrared heater which facilitates the packaging and transportation of such heater. The tubular heat exchanger is formed as a plurality of discrete heat transfer subsections which are typically separately assembled, and then brought together to form the heat exchanger. The heat transfer subsections may be coupled together via a hinge which allows relative rotation between the two subsections, or via conventional hardware. The individual heat transfer pipes of each heat transfer subsection are connected on at least one end to a header plate, which allows the subsequent assembly of the heat transfer subsections.

Abstract: A preheater system for waste oil burners utilizes a primary preheater remote from the burner nozzle and a secondary preheater adjacent the burner nozzle. The primary preheater ordinarily provides heat to the waste oil when the burner is operating. The secondary preheater ordinarily maintains the waste oil adjacent the burner nozzle at atomization temperature when the burner is not operating. Flow of waste oil from the primary preheater to the burner nozzle is precluded when the burner is not operating.

Abstract: The distance between the combustion nozzle and the pump of a waste oil heater can be significantly increased by using a positive displacement pump which is proximate to the reservoir and remote from the nozzle, contary to the usual positioning of oil delivery pumps. The pump, which is not pressure regulated, thus pushes oil to the nozzle at a constant flow rate regardless of oil pressure at the nozzle.

Abstract: The distance between the combustion nozzle and the pump of a waste oil heater can be significantly increased by using a positive displacement pump which is proximate to the reservoir and remote from the nozzle, contary to the usual positioning of oil delivery pumps. The pump, which is not pressure regulated, thus pushes oil to the nozzle at a constant flow rate regardless of oil pressure at the nozzle.