Abstract: A method and apparatus for recovery of heat from the flue gas of the combustion furnace of a steam boiler or power generation plant uses a heat pump heat extracted from a lower temperature point in the system to a higher temperature point in the system. The flue gas is passed through an economizer to preheat the boiler feed water. The flue gas then passes to a direct contact gas cooler where a second stream of cooling water extracts heat from the flue gas. The second stream of cooling water is passed through the evaporator of the heat pump to heat a refrigerant. The refrigerant is compressed and then condensed in thermal contact with the boiler feed water to heat it before it enters the economizer. In a second embodiment a power generation plant has a steam turbine and an auxiliary vapor turbine. The flue gas is passed through a gas cooler and gives up heat to a stream of cooling water.

Abstract: An automatic water heater system having, contained in a tank, a plurality of vertically extending spiral flame tubes surrounded by substantially vertically extending heat tubes which join the top ends of the spiral flame tubes to form a common exhaust outlet for both sets of tubes, thereby greatly increasing the surface area contact between the water and transfer medium. The heat tubes are especially designed to provide an outlet drain for possible condensation that can develop so as not to drain out through the flame tubes and onto the flame. A heat trap, to capture heat from the hot flue gases otherwise lost by normal passage up through the chimney, may be provided, as well as a blower in the exhaust outlet. The above described structure can be assembled either as a combination heating and storage tank in a single unit, or as a separate component heating unit connected to the storage tank located alongside it.

Abstract: A reduced wreath condensation boiler. A feed duct for fresh oxygen-carrying air taken from the atmosphere and an exhaust duct for exhausting diluted combustion products to the atmosphere downstream from the extractor fan are essentially parallel, but not coaxial, minimizing heat exchange. A first heat exchanger is disposed above the heating body for providing heat exchange between the fresh air from the feed duct and the combustion products from the heating body prior to dilution. Deflectors channel a portion of the air from said first heat exchanger to sweep the free space situated between the heating body and its airtight enclosure, while the remainder of the air from the first heat exchanger is directed towards the burner. At least one calibrated orifice injects the air which has swept over the heating body into the exhaust duct for the combustion products upstream from the extractor fan. This boiler reduces the wreath of water vapor where the flue gases are exhausted to the atmosphere.

Abstract: A heat extractor system for a furnace, said furnace including a burner with a chimney that is connected but is normally not in operation. Instead, the furnace is connected to a vent in parallel with the chimney through a draft-inducing arrangement including a water spray in which water is heated and circulated to a point where the heat from the water is utilized. Due to the parallel arrangement of the vent and chimney, if the vent fails to operate, it will function in a fail-safe manner, with the combusted gases from the burner leaving through the chimney.

Abstract: An apparatus functioning as a high-efficiency water heater. This apparatus passes a combustible mixture of gas and air from an impeller into the hollow interior of a cylindrical gas burner. The combustible mixture flows out through apertures in the cylindrical walls of the gas burner and is burned on a cylindrical flame holder as it emerges; the size of the apertures prevents flash-back of the flames of the combustible mixture into the gas burner. Heat is transferred from the flame to the walls of a cylindrical combustion chamber surrounding the gas burner and the combustion products generated pass to a heat exchanger comprising a vertical riser and a downwardly extending helical section which ensures maximum heat transfer to water in a tank surrounding the combustion chamber and heat exchanger. Hot water is discharged from the tank as needed for domestic uses and to another heat exchanger in an air heating duct.

Abstract: Apparatus is provided for heating liquid, utilizing a power burner for burning a combustible fuel. Elongated pipes comprising a flue and a water jacket extend horizontally from the power burner, the flue and water jacket being long enough so that at least some of the exhaust products of combustion exiting through the flue are cooled below the dew point of water so that the latent heat of vaporization from these exhaust products is transferred to the water circulating in the water jacket. A baffle is disposed within the interior of the flue for effecting gas turbulence to maximize heat transfer. The end of the flue remote from the burner has a glass lining to prevent corrosion of the flue from condensate formation, and a condensate drain is provided. The drain includes a U-tube with limestone chips or the like disposed therein for neutralizing condensate flowing through the U-tube.

Abstract: The Multiple Segments Gas Water Heater with Water Jacket is an invention to increase, by several times, the efficiency of a gas water heater presently used in homes. This device prevents energy loss of hot air escaping to the atmosphere, coming from combustion of fuel. This is fulfilled by increasing heat exchange surface area in the heater by segmentation of the water tank and by preheating the cold water in the water jacket placed around the segmented water tank composed of multiple heat exchanger segments.

Abstract: A system for recovering the waste heat normally exhausted in the atmosphere by blast furnace stoves or other variable temperature process heaters. The system comprises a heat exchange apparatus located in the exhaust stack, heat transfer means for carrying the waste heat absorbed from the exhaust gases to a location remote therefrom, and a second heat exchange apparatus for releasing the transferred waste heat for beneficial use at the remote location. This invention also includes a reservoir for storing the heat transfer fluid used in the system and also the reservoir acts as a heat sink to moderate the temperature variation of the heat transfer fluid. The system also includes means for controlling temperature of the first heat exchanger and means for controlling the temperature of the variable temperature process heater. The preferred heat transfer fluid is maintained as a liquid during its use in the system.

Abstract: A method of preventing corrosion in boiler plant equipment when cooling flue gases originating from a combustion plant, such as flue gases containing sulphur oxide or organic acids, to a temperature beneath which sulfuric acid condenses (sulfuric acid dew point temperature) and a further temperature defined as an upper permitted wall-temperature of the stainless steel. The upper permitted wall temperature is with respect to the stainless steel material from which the walls are made and the prevailing partial pressure of water vapor present in the gases. This limiting temperature is specific to each stainless steel. The heat exchange is by means of a coolant, suitably water, located on the other, i.e.

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 recovery apparatus for boilers, or the like, comprising a heat recovery housing having a gas inlet and a gas outlet disposed within the bottom and the top, respectively. A plurality of interconnected water conduit tubes is provided. A plurality of by-pass dampers pivotally connect between the pair of end walls within the heat recovery housing such that when the by-pass dampers are in a closed position, the closed by-pass dampers define a generally flat by-pass structure angularly disposed with respect to the horizontal plane. A plurality of exit dampers is pivotally connected between the pair of end walls such that when the exit dampers are in a closed position, the closed exit dampers define a generally horizontal flat exit structure extending between the pair of end walls.

Abstract: A convective heater for heating fluids such as a coal slurry is constructed of a tube circuit arrangement which obtains an optimum temperature distribution to give a relatively constant slurry film temperature. The heater is constructed to divide the heating gas flow into two equal paths and the tube circuit for the slurry is arranged to provide a mixed flow configuration whereby the slurry passes through the two heating gas paths in successive co-current, counter-current and co-current flow relative to the heating gas flow. This arrangement permits the utilization of minimum surface area for a given maximum film temperature of the slurry consistent with the prevention of coke formation.

Abstract: There is described here a gas water heater consisting of a blower (1), a premixing device (2), a gas burner (3), a heat exchanger (4), and a waste gas heat exchanger (5). Gas burner (3) works as super-stoichiometrically premixing burner and has a burner plate (9) which is cooled on the reverse side and which has a plurality of mixture passage openings (10). Heat exchanger (4) extends through two chambers (6, 7) which are located next to each other and through which waste gas flows in opposite directions. Condensation heat exchanger (5) works in the counter-current and consists of star-shaped section pieces through which heating water flows centrally and which are arranged vertically. Waste gas heat exchanger (5) and premixing device (2) run parallel to each other.

Abstract: Exhaust gas treatment method and apparatus extract heat from an exhaust gas by operating in a water-condensing mode which allows more heat to be recovered, removes particulate matter and condensed acid from the exhaust gas, and washes heat exchange surfaces to keep them clean and wet to improve heat transfer. Systems for heating water, air and both water and air are disclosed. Methods of constructing and assembling improved heat exchangers are disclosed.

Abstract: A high efficiency fluid heater used in conjunction with an infrared heater and the like. The heater circulating a fluid such as cold water in a flue housing through a scrubber section and a contact section greatly exposing the water to the heat of the heater and flue gases thereby increasing the efficiency of heating the fluid.

Abstract: An apparatus is described capable of functioning as a high-efficiency water heater. This apparatus passes a combustible mixture of gas and air from an impeller into the hollow interior of a cylindrical gas burner. The combustible mixture flows out through apertures in the cylindrical walls of the gas burner and is burned on a cylindrical flame as it emerges from the gas burner; the size of the apertures prevents flash-back of the flames of the combustible mixture into the gas burner. Heat is transferred from the flame to the walls of a cylindrical combustion chamber surrounding the gas burner and the combustion products generated pass to a heat exchanger comprising a vertical riser and a downwardly extending helical section which ensures maximum heat transfer to liquid in the tank surround the combustion chamber and heat exchanger. The apparatus may be used solely as a water heater or may serve as a combined gas furnace and water heating system.

Abstract: Exhaust gas treatment method and apparatus extract heat from an exhaust gas by operating in a water-condensing mode which allows more heat to be recovered, removes particulate matter and condensed acid from the exhaust gas, and washes heat exchange surfaces to keep them clean and wet to improve heat transfer. Systems for heating water, air, and both water and air are disclosed. Methods of constructing and assembling improved heat exchangers are disclosed.

Abstract: A heat recovery system recovers heat from flue gases from a furnace or the like and a hot water cylinder. Flue gases are passed through series of chambers in which coils are located. Water is passed through the coils in a direction opposite to flue gas flow to maximize heat transfer and the heated water is passed to either a heat radiating system or into preheater tank for the hot water supply. The coils for the heat radiation and water heating are in separate circuits and the flue gases from the hot water is passed only over the coil used for water heating. Pumps are used for water recirculation in both the heat radiating circuit and the water heating circuit. The system has application to domestic and industrial furnaces which provide gaseous combustion products with recoverable thermal energy and permits the use of a small diameter exhaust vent without adversely affecting the ignition and combustion system of conventional furnaces.

Abstract: In a water heating system, vapor in the products of combustion gases is condensed in a secondary heat exchanger positioned in a housing with the primary heat exchanger and combustion chamber. The two heat exchangers are coaxial coils with the secondary coil surrounding the primary. Gases flow radially through the primary coil, axially along a baffle and then axially through the secondary coil at an increased velocity. The gas/air mixture is burned in a burner within the primary heat exchanger and the gas product are drawn through the exchangers by a blower. A water storage tank is designed to enhance stratification of hot water over cooler water. The cooler water is used to condense vapor in the secondary heat exchanger.

Abstract: An energy recovery system for an incinerator. Hot flue gases from the incinerator are discharged into a vertical stack and the lower end of the stack is connected through an auxiliary conduit to a heat exchanger, such as a steam or hot water boiler. An induced draft fan draws the hot flue gases through the conduit and boiler to generate steam or hot water and a damper is located within the conduit. A fuel burner is connected in the conduit and operates to supply heat to the boiler during periods when the incinerator is not operating. A first flow sensing mechanism is located in the conduit upstream of the boiler, while a second flow sensing mechanism is positioned in the stack downstream of the connection of the stack and the conduit.

Abstract: A device for heating fluid with the exhaust gases from a furnace or stove includes a coiled fluid conduit mounted within the exhaust conduit and means such as baffles for directing the exhaust gases through and around the coiled fluid conduit. In one embodiment, the fluid in the coiled conduit is water from a cold water source which, after passing through the coil and being heated by the exhaust gases, flows to a water heating tank in a pre-heated condition.

Abstract: A heat exchanger comprising a coil assembly mounted in a broiler used in restaurants for example where the temperature of the broiler is about 500.degree. F., such coil assembly being connected to an intermediate holding tank into which cold water is fed from a public water supply through a downwardly extending pipe in the intermediate holding tank having its discharge opening near the bottom of the tank. An outlet port is located slightly above the level of the discharge opening of the downwardly extending pipe, and a conduit is connected between the outlet port of the holding tank and the coil assembly mounted in the broiler, with a pump connected in this conduit to pump cold water from the bottom portion of the intermediate holding tank to the coil assembly mounted in the broiler. A return conduit leads from the coil assembly back to an inlet port of the intermediate holding tank located in the upper part of such tank whereby water which has been heated to about 100.degree. F. from about 40.degree. F.

Abstract: A new and improved incinerator steam generation system subjecting to combustion debris such as municipal waste, utilizing the heat derived therefrom to produce steam for steam boiler, electrical generating facilities, heating facility for industrial or commercial plants, and so forth. This is provided with a series of boilers and controls, both manually adjustable and also automatic, whereby the possibility of fire dangers are minimized, created temperature ranges of boiler gases are constrained to desirable limits, dump stack facilities are automatically controlled as to particular effectiveness for differing types of operating conditions, and where safety features are incorporated to shut down gas flow through the boiler during periods of boiler-water deficiency, excess steam generation relative to demand, and other conditions. Within the furnace area proper the pressure conditions are predetermined and are controlled during operation for desired efficiency, vapor removal, and materials' combustion.

Abstract: A hot water boiler, in particular a light metal central heating boiler, having a combustion chamber and a burned gases flue above the chamber, both the chamber and the flue having a common separating wall with a common water passage, the lower part of the flue, joining the upper part of the combustion chamber, being provided with extensions from the wall for increasing the heat exchange surface thereof and providing a first heat exchanger for the burned gases, the upper part of the flue being provided with inclined ribs extending from the wall to increase the heat exchange surface thereof and forming a second, condensing heat exchanger, the ribs forming condensate collectors cooperating with condensate drains.

Abstract: Apparatus for delivering hot water includes a vessel for releasably containing water and a heat generator compartment in heat transfer relation to the vessel. A conduit in the vessel circumscribes the exhaust funnel of the heat generator and has an inlet port in fluid communication with the vessel and an outlet port in fluid communication with the exterior of the vessel. An after-burner may be situated in the exhaust funnel in registry with the conduit and the conduit can be a coil arranged in spiral configuration.

Abstract: A heat exchanger and vaporizer adapted for mounting on an existing flue for utilizing heat which is otherwise lost and for providing moisture for space heating and conditioning. The heat exchanger and vaporizer includes a central stack for unimpeded transport of flue gases; a casing, with air inlet and outlet, enveloping the stack; a vaporizor contained within the casing for efficient heat transfer and for room conditioning; and a motor-fan unit for producing an airflow through the casing. The vaporizer is in the form of non-corrosive heat conductive helical tubing for maximizing heat transfer in a given volume, for maintenance free use and for convenience in assembly. The vaporizer is provided with a plurality of vapor vents on its upper surface and a pour spout located externally of the casing.

Abstract: A powered downdraft type combustion unit which substantially completely gasifies the fuel burned therein during the combustion process and produces a maximum amount of usable heat for utilization at a location remote from the combustion unit is provided. The present combustion unit includes a heavily insulated outer shroud enclosing insulated sequential combustion chambers to prevent heat loss from the combustion chambers. A primary combustion chamber is separated from a secondary combustion chamber by a plurality of refractory grates. Fuel is fed to the primary combustion chamber to be combusted therein, and the products of this stage of combustion then pass to the secondary combustion chamber where the combustion process is completed. The heat-containing combustion gases are directed from the secondary combustion chamber to a heat utilizing appliance through a conduit connected therebetween.

Abstract: Disclosed is an add-on boiler that has an insulated cover covering a housing that carries a finned heat-recovery coil. The add-on boiler is mounted on the casing of a heating device to heat water in the coil with heat transferred by conduction and radiation. The insulated cover maintains the heated water in the coil at a high temperature to prevent the internal operating temperature of the heating device from dropping below the critical temperature at which creosote forms from the flue gases.

Abstract: A device for heating air by flue gases in steam boilers and furnaces, comprises a supply flue, sections mating therewith, and a device for protection of heat-exchange tubes against abrasive wear arranged in the flue. Each section comprises heat-exchange tubes attached to tube plates. The device for protection of the heat-exchange tubes against abrasive wear incorporates at least one screen formed by corrugated sheets facing each other and mating along the lines of contact of sheet convex portions, whereby cells are made up.

Abstract: Heat recovery attachment in combination with the combustion gas discharge duct of a gas-fired or oil-fired heating apparatus having a liquid or air circuit, substantially comprising a heat exchanger having a supply and a discharge connection for the combustion gases to be passed therethrough, and a fan which encourages combustion gases to flow through the heat exchanger. The heat exchanger extends at most partly into the combustion gas discharge duct, and means are present to direct the exit gases, after heat exchange, obliquely upwards into the combustion gas discharge duct in such a manner that they form a gas barrier extending substantially across the transverse section of the combustion gas discharge duct.

Abstract: This invention relates to method and apparatus used as an addition to any existing heating system--burning any fuel--for heat recovery from stacks and chimneys. It uses a suitable heat exchanger mounted at the apex of such stacks, by virtue of which location no natural draft is lost. The system includes a circulating pump, a thermostat, an expansion bottle, a condensate trough, a cap and dome which jointly serve to act as unloaders to protect the system liquid from being boiled off. Both sensible heat and the latent heats of moisture in the fuel and in the vapor produced as a combustion product, can be scrubbed out. The use is to effect economies and to reduce environmental contamination wherever fuels are fired.

Abstract: A fuel-fired fluid heating appliance, such as a gas-fired boiler (FIG. 1) is provided for heating a fluid such as water circulating in a central heating system. The boiler includes a flue 4 for discharging the combustion products, e.g. exhaust gas, to atmosphere by way of a heat exchanger 8 incorporated within a portion 6 of the flue 4 external of the boiler housing 1. The heat exchanger 8 is provided with an inlet 16 to receive water from a return flow pipe 36 and an outlet 17 to discharge the water to the inlet 35 of the boiler primary heat exchanger 3. The heat exchanger 8 (FIG. 2) is provided with a number of ducts 18 along which the exhaust gas travels to transfer its heat to the water circulating within compartments 29 to 33 within the heat exchanger housing 15. The external portion 6 of the flue 4 is disposed at an angle of 20.degree. downwardly to the horizontal so that any exhaust gas condensing in the heat exchanger 8 flows down the flue base 9 to a discharge spout 10 and collector weir 11.

Abstract: A waste heat boiler (10, 38) of the type which is particularly suited for use in marine applications and which incorporates a feed mixing nozzle (50) that is operative for purposes of effecting, by utilizing steam taken from the steam generating bank (20, 48), a preheating of the feedwater that is fed to the steam drum (14, 42). In addition to the aforesaid feed mixing nozzle (50), the subject waste heat boiler (10, 38) includes a feedwater control valve (12, 40), a steam drum (14, 42), a circulation pump (18, 46), a steam generating bank (20, 48) and a centrifugal water separator (16, 44). The feedwater control valve (12, 40) is employed to modulate the flow rate of the incoming feedwater in order to maintain the desired level of water in the steam drum (14, 42). In turn the latter steam drum (14, 42) is intended to function in the manner of a reservoir for the circulating water that through the operation of the circulating pump (18, 46) is supplied to the steam generating bank (20, 48).

Abstract: A water heater of the combustion type having a collecting assembly for collecting the drain water resulting from combustion to prevent corrosion of components of the heater by the drain water.

Abstract: A flameless nitrogen vaporizing unit includes a first internal combustion engine driving a nitrogen pump through a transmission. A second internal combustion engine drives three hydraulic oil pumps against a variable back pressure so that a variable load may be imposed upon the second engine. Liquid nitrogen is pumped from the nitrogen pump driven by the first engine into a first heat exchanger where heat is transferred from exhaust gases from the first and second internal combustion engines to the liquid nitrogen to cause the nitrogen to be transformed into a gaseous state. The gaseous nitrogen than flows into a second heat exchanger where it is superheated by an engine coolant fluid to heat the gaseous nitrogen to essentially an ambient temperature. The superheated nitrogen is then injected into the well. The engine coolant fluid flows in a coolant circulation system. Heat is transferred to the coolant fluid directly from the internal combustion engine.

Abstract: A heating system for supplying utility water and a heating fluid for space heating purposes comprises a unit fired by a burner and having a recuperator traversed by the combustion gases and forming a first zone for heating the space-heating fluid and a second zone for heating the utility water. According to the invention, a heat exchanger is provided along the path of the utility water delivered from the second zone to a reserve tank and the heat exchanger is connected in a bypass across the feed and return lines of the heating fluid circulating path. A control responsive to the temperature in the tank regulates the flow through the bypass while a further temperature control responsive to the feed side temperature of the space-heating circulation path controls the fuel supplied to the burner and the rate of combustion gas flow through the heat exchanger.

Abstract: A flue gas heat recovery apparatus for reconstituting thermal energy normally lost through the venting of flue gases from a heat liberating plant is disclosed. The apparatus can be employed with forced air or hydronic systems and includes a compressor which draws hot gases from the exhaust flue through a first heat exchanger located in a cold fluid return to the plant, thereby transferring thermal energy from the gases to fluid (typically air or water) flowing in the return duct. The compressor operates to substantially elevate the pressure and temperature of the flue gases passing therethrough and discharges them through a second heat exchanger located in the return duct upstream of the first heat exchanger to further transfer thermal energy from the gases to the fluid flowing therein. Gases exiting the second heat exchanger are directly vented to the atmosphere or, alternatively, are first filtered to remove particulate matter.

Abstract: A convective heater for heating fluids such as a coal slurry is constructed of a tube circuit arrangement which obtains an optimum temperature distribution to give a relatively constant slurry film temperature. The heater is constructed to divide the heating gas flow into two equal paths and the tube circuit for the slurry is arranged to provide a mixed flow configuration whereby the slurry passes through the two heating gas paths in successive co-current, counter-current and co-current flow relative to the heating gas flow. This arrangement permits the utilization of minimum surface area for a given maximum film temperature of the slurry consistent with the prevention of coke formation.

Abstract: A water heating system for use with an incinerator. The incinerator includes a combustion chamber to burn waste material and a stack is connected to the combustion chamber to discharge the hot flue gases. Located within the stack is a heat exchanger. A water heating system is located within a building and includes a closed conduit having a pump to continuously circulate hot water through the conduit. A second conduit connects the first conduit with the heat exchanger in the stack and a second pump is employed to circulate water through the second conduit. In addition, a bypass is connected across the second conduit. A valving system is operable during periods when the incinerator is not operating to flow water through the first conduit and to separately flow water through the second conduit via the by-pass, so that water will continually flow through the heat exchanger.

Abstract: A water tempering system for preheating water comprises a storage tank for tempered water; a water tempering unit containing S-shaped heat exchange tubes positioned in the exhaust flue of a furnace; first conduit means for conveying water from the storage tank to the tempering unit; and second conduit means for conveying water from the tempering unit to either the storage tank or an outlet tube for the water tempering system.

Abstract: An economizer is provided for building heating systems and the like, of the type having a forced air furnace with adjacent combustion and heat exchange chambers, and a hot water reservoir or heater. The economizer comprises lower and upper heat transfer coils shaped for positioning adjacent the combustion and heat exchange chambers respectively of the furnace. An insulated standpipe interconnects the two coils, and the outlet of the upper coil is communicated with the inlet of the water heater. During use, water flowing through the economizer is heated in the lower coil and flowed to the upper coil to transfer additional heat to the air flowing through the heat exchange chamber, and simultaneously preheat water fed into the water heater.

Abstract: A water preheating system extracts heat energy from the exhaust gases of a laundry dryer. The hot exhaust gases are introduced into a heating chamber where they are directed at the underside of a water storage tank used to furnish preheated water to a conventional hot water heater. A condensation collection and disposal system collects condensation for re-evaporation or drainage.

Abstract: The invention relates to a heating installation for home or industrial use. It is of the type including a heat source associated with a heat pump of which the heat produced is given up to a heating fluid contained in an enclosure connected to heating members placed in the premises to be heated. It is characterized in that at least one part of the heat produced by the exhaust heat source is capable of being transferred to the heating fluid and of being added to that given up by the heat pump. The invention is particularly useful as a boiler for a heating system.

Abstract: In a boiler or an industrial furnace, a temperature detecting sensor is mounted at the heat absorbing side of a heat pipe of a waste heat recovery device which is disposed in part of the path of exhaust gas. With an output signal of the temperature detecting sensor, a flow rate control valve is controlled, and a liquid discharging shield is utilized to maintain the flow rate of the liquid to be supplied in correspondence with the flow rate of the liquid to be discharged. The effective area of the heat pipes coming in contact with the liquid is varied to maintain the temperature at a heat absorbing side higher than the dew point of sulfur oxide, thus preventing the heat pipes from corrosion, exhaust ducts and so on, and allowing heat absorbing operation to be performed in accordance with the exhaust gas discharge temperature.

Abstract: Device for preventing flashing to steam in an economizer of a flow-through steam generator wherein the economizer has heating surfaces disposed downstream of an evaporator and superheater surfaces in direction of a flue-gas path, including at least one partition separating the cross section of the flue-gas path in vicinity of the economizer into at least two joint areas separated from one another, the economizer having tubes disposed only in one of the thus formed joint areas, and further including shut-off devices for the flue-gas disposed upstream of the tubes of the economizer as viewed in the direction of the flue-gas path.

Abstract: In a water heating system, vapor in the products of combustion gases is condensed in a secondary heat exchanger positioned in a housing with the primary heat exchanger and combustion chamber. The two heat exchangers are coaxial coils with the secondary coil positioned below the primary. Gases flow radially through the primary coil and then axially through the secondary coil at an increased velocity. The gases are then used to pre-heat a gas/air mixture in a third heat exchanger within the secondary heat exchanger. The pre-heated gas/air mixture is burned in a burner within the primary heat exchanger and the gas products are drawn through the exchangers by a blower. A water storage tank is designed to enhance stratification of hot water over cooler water. The cooler water is used to condense vapor in the secondary heat exchanger.

Abstract: A flue gas heat recovery apparatus is employed with a system of appliances such as a gas furnace and hot water heater, each having separate exhaust gas flues. The apparatus includes a gas-to-liquid heat exchanger in thermal communication with the two flues to simultaneously extract heat therefrom and a liquid-to-gas heat exchanger disposed within the furnace cold air return duct. A pump circulates water between the exchangers in response to a control signal to employ the recovered heat to preheat the cold air entering the furnace through the cold air return duct. A hysteretic control circuit monitors exhaust gas temperature and provides for system operation between high and low gas temperature limits. In the preferred embodiment of the invention, a furnace blower override feature is employed to energize the blower during periods of pump operation.

Abstract: This invention relates to the conservation of energy in a domestic gas water heater by utilizing the hot exhaust gases in a gas water heater for the preheating of the incoming unheated water into the water heater.The exhaust gases from a domestic gas water heater carry wasted heat and the present invention provides a mean to reclaim part of the wasted heat for the preheating of the incoming unheated water during hot water usage periods. During non hot water usage periods the heat in the exhaust gases is not reclaimed to prevent overheating of the water and also to prevent the formation of water deposit in the preheating assembly or heat reclaimer. During the non hot water usage periods the heat produced in the water heater is normally needed only to maintain the desired water temperature of the stored water in the water tank of the water heater.Due to the rapid heating or recovery rate, the present invention enables the use of a smaller water heater.

Abstract: A heat scavenger or heat recovery system is provided for use with a furnace such as a hot air furnace, wherein the incoming air to the furnace is preheated, and wherein the exhaust or waste heat that is ordinarily lost up the chimney is recovered and used for preheating the incoming air for the furnace to be used in a home or other building.

Abstract: A boiler has a chamber to contain a charge of wood that rests on the bottom of the chamber with the major portion of the charge within a water jacketed upper portion of the chamber but free to settle as combustion progresses. Combustion is confined to the bottom portion of the chamber due to the cooling effect of the water jacket and to a turbulent cross draft in the combustion zone. A special venturi section in the flue coupled with a pressure blower both induces the flow of hot gases from the combustion zone through a second chamber and a heat exchanger and also provides a stream of air from the venturi section to create the cross draft. An oil burner may be used in conjunction with the second chamber as an alternate heat source. The boiler also has a special base construction and assembly features.