Abstract: A waste heat recovery apparatus is disclosed which recovers the waste heat of high temperature exhaust gas discharged from a furnace. The apparatus includes a radiation body made of ceramic material, which is formed with a heat radiation surface arranged adjacent to an exhaust gas outlet of the furnace, and directed toward the inside of the furnace. The radiation body has a plurality of regular channels allowing passage of the exhaust gas therethrough. Exhaust gas passes through the channels and heats the radiation body, and a substantial amount of the holding heat of the exhaust gas is radiated from the radiation surface toward the inside of the furnace, allowing an efficient waste heat recovery.

Abstract: An improved heat pipe comprising a duct having disposed at opposite ends thereof an evaporator with wick-lined hollow fins in the form of extended corrugations thereon, and operable to supply heat to the evaporator comprised of a gas combustor having an internal volume for containing the evaporator and combustion air for supply to a combustion chamber located therein; a wick capable of transporting liquid by capillary action lining substantially all internal surfaces of said heat pipe; an external heat sink operable to remove heat from the condenser; and a heat transport medium contained by said heat pipe. The evaporator is further comprised of a coarse porous material lining and completely filling the spaces within the hollow fins open to the evaporator for increased structural stiffness and ease of fabrication; and a porous mass completely filling the evaporator for increased compressive strength.

Abstract: A retrofit heat recovery device for installation on existing hot air furnaces. The device is arranged to make use of the existing hot pin furnace blower.

Abstract: A heat exchange device for transferring heat from a first medium to a second medium. The device includes a first chamber through which the first medium passes, a second chamber through which the second medium passes, the second chamber having a common boundary with at least a portion of the first chamber, and guide structure for causing the second medium to move in a spiral path through the second chamber and over the common boundary between the first and second chambers.

Abstract: The heat recovery device includes a section of standard flue pipe carrying a single row of a plurality of hollow, cylindrical heating tubes extending diametrically through the flue pipe section and a separate housing defining an air flow chamber surrounding the portion of the flue pipe section containing the heating tubes. A fan inside the housing draws ambient air into the housing and propels a flow of air toward a heated air outlet, both through the heating tubes and over the outer surface of the flue pipe section. A catalytic combustor for reducing air pollutants and potential creosote deposits is mounted in the flue pipe section upstream of the heating tubes. The flue pipe assembly is removably mounted on the housing so it can be removed in the event it fatigues and/or becomes plugged with carbon or creosote deposits during use. A thermostat on the flue pipe section turns the fan on and off when the temperature in the flue pipe section is respectively above and below a predetermined temperature.

Abstract: A heat exchanger for extracting and recovering waste heat from the flue of a heater, such as a furnace. The present heat exchanger includes a housing having a plurality of sealed, oil filled, parallel metallic finned tubes arranged around the periphery of the heat extractor chamber of the heat exchanger. Hot flue gases from the furnace travel between the inner housing and the outer housing. Thus, the hot flue gases pass through and around the finned tubes thereby heating the oil inside, so that a very large proportion of the heat of the flue gases is extracted by the finned tubes. The plurality of finned tubes are all connected together as one unit exposed to hot flue gases, thus once oil is heated in the tubes, the unit retains the heat even when furnace is not operating. The tubes are made of copper and act as an oil reservoir and heat sink for the heat absorbing fins. A blower exhausts clean heated air out of the rear duct for useful heating.

Abstract: The energy requirements of a sock finishing factory consisting at least of a dye house, boarding room and a warehouse are greatly reduced and the working conditions of employees are improved by utilizing waste heat from the boarding room to provide heat for the dye house water requirements and seasonal heat for the warehouse and by supply some of the heat for the dye house water from the air conditioning condenser system.

Abstract: A secondary heat exchanger is positioned within a cold air return plenum of a forced air gas or oil fired furnace to preheat cold air drawn into the furnace through the cold air plenum. A heat recovery flue pipe is connected between a primary flue pipe of the furnace and the secondary heat exchanger, and an exhaust pipe is connected between the secondary heat exchanger and the outside of a structure served by the furnace. A secondary blower coupled to the exhaust pipe draws hot combustion gases from the primary flue pipe through the heat exchanger and exhausts cooled combustion gases to the outside. The secondary heat exchanger comprises a combustion gas inlet plenum and a combustion gas outlet plenum, with a plurality of heat conducting pipes sealingly connected therebetween.

Abstract: The heat recovery device has a flue pipe assembly including a section of standard flue pipe carrying a plurality of hollow, cylindrical heating tubes extending diametrically through the flue pipe section in axially spaced, parallel relationship and a separate housing defining an air flow chamber surrounding a portion of the flue pipe section. A fan inside the housing draws ambient air into the housing through an ambient air inlet located on the same side of the flue pipe assembly as the inlet of the heating tubes and propels a flow of air both through the heating tubes and over the outer surface of the flue pipe section towards a heated air outlet located on the same side of the flue pipe section as the discharge ends of the heating tubes. The flue pipe assembly is removably mounted on the housing so it can be removed in the event it fatigues and/or becomes plugged with carbon or creosote deposits during use.