Abstract: A fuel-air combustion chamber with improved mounting and thermal distribution features. The combustion chamber is formed with a flange adapted for receiving a plurality of retainer rings therearound for direct securement of the flange to a burner mounting plate adjacent a fuel-air nozzle for generating heat within the combustion chamber. The combustion chamber is also temporarily supported within the furnace housing by a combustible support leg affixed thereto. In this manner, the combustion chamber is supported during shipping and handling by a support leg which is automatically disintegrated during use of the combustion chamber.

Abstract: A single forced air furnace (10) may be installed in any of an upflow, downflow, or horizontal airflow orientation, with discharge of flue gases either opposite to or concurrent with the primary airflow path. The combination of design features which provides this versatility includes the following features: an inducer assembly (24) for withdrawing flue gas from the furnace heat exchanger (20), which inducer assembly (24) may be positioned to direct the discharge of flue gas in a selected one of a plurality of directions; an optional internal flue duct (64) for directing the flue gas through the furnace vestibule chamber then through the furnace housing (12); and the fact that the furnace housing (12) is dimensioned and configured so that the furnace may be supported on any one of four different sides (O, I, S.sub.1, S.sub.2) of the furnace housing (12).

Abstract: A furnace including an elongated housing having an air intake adjacent one end of the housing and an air discharge vent adjacent the other end of the housing utilizes a substantially U-shaped heat exchanger positioned within the housing and a partition supported within the housing so as to separate the interior of the housing into first and second zones. A fuel burner assembly directs a flame and attending combustion products into one leg section of the heat exchanger so that the heat generated by the flame and combustion products are absorbed through the inside surfaces of both leg sections. The furnace also includes a fan so that a fraction of the air move through the first zone and absorbs heat from the outer surfaces of the one leg section and so that a remainder of the air moves through the second zone and absorbs heat from the other surfaces of the other leg section. The partition provides a first and a second opening through which the first and second zones communicate with one another.

Abstract: A furnace includes at least one heat exchanger with first and second plate members secured together to define passageways that form serpentine flow paths between an inlet passageway and an outlet passageway. The inlet passageway receives hot products of combustion from a burner which extends into it. A blower induces the flow of the combustion products through the heat exchanger. A second blower induces the flow of air over the surfaces of the exchanger.

Abstract: A fuel-fired forced air condensing furnace has installed therein a recuperative heat exchanger assembly with a primary heat exchange section operative, during furnace operation, to transfer sensible combustion gas heat to air being flowed through the furnace, and a secondary heat exchange section operative to transfer latent combustion gas heat to the air. The secondary heat exchange section includes a finned tube heat exchanger structure extending between spaced apart combustion gas inlet and outlet collector boxes.

Abstract: A coupling box for a condensing furnace having primary and secondary heat exchangers places the discharge ports of the primary heat exchanger in fluid communication with the inlet ports of the condensing heat exchanger. A baffle in the coupling box directs the flow of flue gas evenly therein to maintain temperature equilibrium so that water vapor does not condense in the coupling box.

Abstract: In a multi-poise furnace having multiple parallel heat transfer stages, each stage having superimposed flow passages lying in a common plane. The last passage in each stage containing laterally-disposed indentations in opposed side walls for increasing the heat transfer surface area, and the walls of the last passage being further configured to conduct any condensate formed in the heat exchanger out of the exit region of the exchanger, regardless of the furnace orientation.

Abstract: Poor heat exchange in a heat exchanger between a flue gas passing through the heat exchanger and air being forced through the heat exchanger can be improved in a heat exchanger and combustor (30) for exchanging heat between a forced air stream and a flue gas generated by a plurality of spaced, parallel burners (44) with a construction including spaced, upper and lower headers (32, 34), a plurality of tubes (50), one for each burner (44) extending in parallel between and mounted to the headers (32, 34). Each tube 50 has a first section (56) of enlarged cross section adapted to serve as a combustor for fuel to generate the flue gas and a narrowed, second section (70) for exchanging heat between the flue gas and the forced air stream. Each second section includes generally flat, parallel spaced walls (58, 60) with each of the walls (58, 60) having dimples (74) therein which are directed toward the other of the walls (58, 60) into substantially contacting or almost contacting relationship therewith.

Abstract: An abatement member for inhibiting formation of oxides of nitrogen in a gas-fired furnace by controlling peak flame temperatures and residence times at the peak flame temperatures is described. The combustion system has at least one heat exchanger conduit having a flow path therethrough and at least one gas burner for burning fuel to produce a combustion flame. The abatement member has a porous refractory body portion having at least one section which is disposed transversely to the direction of flow of gases through the conduit. In one embodiment, the abatement member is a metallic screen having a serpentine shape and positioned within the fire tube. The combustion flame is directed toward and into the inlet of a fire tube and through the screen whereby the screen absorbs thermal energy from the combustion flame at a rate which limits peak flame temperatures to levels which inhibit formation of oxides of nitrogen.

Abstract: A bracket for a hot surface ignitor is provided with a central opening having downwardly directed supporting arms and upwardly directed L-shaped retention arms such that the ignitor can be lockingly engaged with the bracket without creating crack-inducing stresses in the ceramic base of the ignitor. The bracket is further provided with upwardly directed resilient detents that allow the bracket to be securely snapped into the burner box of a gas furnace. The bracket thus positions the hot surface portion of the ignitor within the burner box while positioning the ceramic base and electric supply wires exterior to the box.

Abstract: A tubular recuperative heat exchanger structure is mounted in a housing chamber within a fuel-fired condensing furnace in the vertical flow path of supply air being flowed through the housing by a blower. The heat exchanger structure comprises a primary heat exchanger defined by a vertically serpentined series of combustor tubes into open inlet ends of which a series of inshot-type fuel burners flow flames and hot combustion gases, and a secondary heat exchanger formed from a horizontally extending series of finned heat exchanger tubes having inlets in flow communication with the outlets of the combustor tubes and outlets in flow communication with the inlet of a draft inducer fan.

Abstract: A method and apparatus for preventing splashing condensate from activating the safety pressure switch in a multi-poise condensing furnace includes removing the existing tubing connected to upper and lower pressure taps provided on the collector box of the furnace. T connectors and secondary tubing are then fastened to each of the pressure taps and the existing tubing reconnected to a corresponding T connector.

Abstract: An induced flow condenser furnace has a combustion air intake shoe that connects the combustion air pipe to the burner box, and has a provision for draining off any condensate from the combustion air pipe before it reaches the burner box. The shoe has a tray portion with an open top that mates with an intake opening in one wall of the burner box, and a tube portion that connects at one end with the combustion air pipe and at the other end with an end cap. The latter has a drain nipple to permit escape of the condensate. An internal lip is formed in the tube portion traps condensate when the furnace is poised in an inverted or downflow orientation. This permits the furnace to be poised in any of four orientations. The intake shoe facilitates connection of the inlet pipe and drain tube in all multi-poise configurations.

Abstract: An upflow or downflow furnace comprising a housing; a heat exchanger section in the housing, a blower section in the housing, and a blower deck in the housing having an upward side and a downward side. The heat exchanger section includes at least one heat exchanger and the blower section includes a blower for moving air through the heat exchanger section. The blower deck separates the blower section and the heat exchanger section. The blower deck includes an aperture and means, in proximity to the aperture, for either mounting the blower to the downward side of the blower deck for an upflow furnace configuration or mounting the blower to the upward side of the blower deck for a downflow furnace configuration.

Abstract: There is disclosed a furnace having an air flow path for heated air and combustion products that passes through a condensing heat exchanger. Condensate forming in regions of negative and positive pressure is separately conducted to a unitary condensate trap of minimal vertical height incorporating therein separate traps for handling the high and low pressure gaseous environments. The condensate is drained through a common outlet port into the atmosphere or into a drain pipe.

Abstract: A forced air furnace (11) has a heat exchanger (35) with one or more tube pack assemblies (10). Each tube pack assembly (10) has a burner (21) situated to fire into a primary fire tube (30) which is mechanically connected through a transition cap (36) to a plurality of secondary tubes (37, 38, 39, 41) returning combustion products from the primary fire tube (30) to a collection manifold (24) at the intake end of a draft inducer assembly (23) for discharge of the combustion products to a flue. In the preferred embodiment, the transition cap (36) is connected to the primary fire tube (30) and to the secondary tubes (37, 38, 39, 41) by a mechanical interlock.

Abstract: A heating furnace is provided with a counterflow heat exchanger defining serpentine up flow fresh air passages and downflow combustion products passages. The exchanger is of sheet metal modular construction.

Abstract: An induced draft, fuel-fired furnace having a heat exchanger with an inlet and an outlet includes a vent having an inlet, a burner, and a vented vestibule in fluid communication with the vent. A blower has an inlet in fluid communication with the heat exchanger outlet, and an outlet disposed at the inlet of the vent. The blower outlet has a cross-sectional area smaller than the vent inlet. The vent inlet and blower outlet define a vent inlet opening. A drafthood formed with an inlet is disposed in the vestibule and forms a plenum in fluid communication with the vent inlet opening. A source of combustion products is disposed in the furnace such that combustion products produced thereby are in fluid communication with the drafthood inlet and vent inlet opening. The source of combustion products includes either a standing pilot or electronic ignitor for igniting fuel operably discharged from the burner.

Abstract: A burner unit for heating a gaseous medium includes a heat exchanger provided with tubes, a space between the tubes connected on the upstream side to a feed duct for the gaseous medium; a combustion chamber connected to the downstream side of the space between the tubes; a burner placed in the combustion chamber; and a fuel supply duct connected to the burner. The side of the combustion chamber remote from the heat exchanger is connected to a first end of the tubes; and a flue gas outlet duct is connected to the other end of the tubes. The elongation of the tubes forming part of the heat exchanger renders the use of a conventional tube plate superfluous. Thus, damage resulting from thermal stresses is avoided.

Abstract: A fuel-fired condensing furnace is provided with a specially designed heat exchanger structure having a metal primary section and a plastic secondary or recuperative section. The primary section is defined by a horizontally spaced series of identically sized, vertically serpentined metal combustor tubes adapted to receive a throughflow of a burning fuel-air mixture discharged from the furnace burner section. Each tube has an essentially straight inlet combustion section sized to permit essentially complete combustion therein of the burning fuel-air mixture received by the tube, and a plurality of vertically spaced horizontal heat transfer sections that are horizontally flattened and narrowed to enhance their combustion heat transfer to supply air being forced upwardly through the furnace housing.

Abstract: A method and apparatus for recirculating flue gas in either a vertical or a horizontal pulse combustor which is dedicated to deliberate one-stage pulse combustion. At least one combustion chamber wall defines a mixing region and a combustion chamber which is adjacent the mixing region. A fuel inlet conduit or a fuel/air inlet conduit is used to supply fuel into the mixing region. An air inlet conduit or a fuel/air inlet conduit is used to supply air into the mixing region. Air valves are in communication with the fuel inlet conduit, the air inlet conduit and/or the fuel/air inlet conduit. An ignition source is positioned within with mixing region for igniting the air/fuel mixture and beginning the pulse combustion process. An exhaust system removes flue gas containing products of pulse combustion. A portion of the flue gas produced during pulse combustion is then recirculated to the mixing region.

Abstract: An improved multi-fuel heater using a porous fuel vaporizer in close proxty to an burner cup the improved heater having means to ameliorate the build up of particulate material between the cup and the vaporizer.

Abstract: A furnace includes a generally cylindrical combustion chamber that is open at one end for receiving a single port inshot target burner. The target burner includes a flame spreader for lowering the heat energy and temperature of the gas flame so as to reduce NO.sub.x emissions. The flame spreader includes a plurality of rods affixed to the target plate or disc.

Abstract: A low NOx burner assembly of a fuel-fired heating appliance is supplied with an air/fuel mixture having a substantially less than stoichiometric air-to-fuel ratio. The air-rich mixture is partially combusted to create primary combustion products disposed within an open inlet portion of a combustor structure having a catalytic converter operatively positioned within an open outlet portion thereof spaced apart from its open inlet portion. A flow of aspirating air is introduced into the combustor structure between the inlet and outlet portions thereof. The aspirating air mixes with the primary combustion products, cools them, and flows with them outwardly through the catalytic converter. This essentially completes the combustion of the remaining fuel within the cooled primary combustion products, and does so at a temperature not appreciably greater than the initial combustion flame temperature to thereby substantially reduce NOx emissions without the use of flame quenching techniques.

Abstract: A gas-fired construction heater which meets the applicable ANSI Standard and operates to supply heated air separately from products of combustion. The products of combustion are permitted to contain no more than a specified percent of carbon monoxide when uncontrolled heater operating conditions are within predetermined ranges. The uncontrolled operating conditions include variations in input rate and supply voltage. A combustion chamber produces the products of combustion and has primary and secondary combustion zones. A heat exchanger receives the products of combustion and transfers heat therefrom to fresh air to be heated. The chamber and the heat exchanger define a tertiary combustion zone. Inlets supply a separate natural combustion draft to each of the primary and tertiary combustion zones. The inlets include a first and a third fixed-area inlet for respectively supplying the separate natural drafts to the primary and tertiary combustion zones.

Abstract: A vaporizing type burner including a cylindrical body, a combustion chamber, a fuel absorbing section for receiving a fuel therein and vaporizing the received fuel therefrom, a mixer tube in which a vaporized fuel and a combustion air are mixed with each other to prepare a mixture gas and an igniting plug for igniting the mixture gas radially ejected from the mixer tube wherein a supporting member for accommodating the fuel absorbing section in the cylindrical body is arranged in such a manner as not to allow the fuel absorbing section to be exposed directly the combustion chamber, a vaporizing chamber is arranged adjacent to the fuel absorbing section and the supporting member so as to allow a part of the combustion gas generated in the combustion chamber to be introduced into the vaporizing chamber without any burning flame, an air swirling chamber includes a plurality of guide plates for imparting a swirling force to the combustion air, the mixer tube is communicated not only with the air swirling chamber

Abstract: The present invention relates to a unitary heat exchanger for an air conditioner which is capable of minimizing the size, weight, and the power consumption thereof, and improving the thermal efficiency. The unitary heat exchanger comprises an air intake member for introducing the room air, and a combustion furnace for firing a fuel with the air introduced through the air intake member to generate a hot combustion gas. A heat exchanger is disposed in line with the furnace for passing the hot combustion gas from the combustion furnace therethrough and heating fresh room air supplied by a blower. An air exhaust member discharges the hot combustion gas from the heat exchange means.

Abstract: A heat exchanger for heating air or another gas, comprising at least one gas-fired burner comprising a metal pipe-shaped combustion chamber which is part of the heat exchanger and extends in the path of the air to be heated, wherein the pipe-shaped burner chamber (4) comprises means for enlarging the heat transfer surface, such as fins (V), with the pipe-shaped burner chamber (4) forming the first pass of at least two parallel passes which communicate at their ends via deflecting boxes (5, 6) and the burner (1) being a high-speed burner.

Abstract: Basically the present invention in it's most simple form or embodiment is directed to a controlled labyrinth heat exchanging oil nozzle assembly for use as a flame producing nozzle within an oil burning heating system, particularly adapted to burning of waste oil. The nozzle assembly comprises a block, the temperature of which is controlled or controllable and in which there is at least one cylindrical bore (preferably two bores are provided) into which director plugs are specially inserted. The block, the bore or bores and the flow director plug or plugs are designed to provide a fuel flow passage which undulates upward and downward thereby increases the dwell time or the time during which fuel is within the block and also creating substantial surface area through which heat is transferred or transferable from the block when it is heated to the fuel flowing in such an undulating manner therethrough.

Abstract: A method and apparatus for recirculating flue gas in either a vertical or a horizontal pulse combustor which is dedicated to deliberate one-stage pulse combustion. At least one combustion chamber wall defines a mixing region and a combustion chamber which is adjacent the mixing region. A fuel inlet conduit is used to supply fuel into the mixing region and an air inlet conduit is used to supply air into the mixing region and thereby form an air/fuel mixture within the mixing region. Air valves are in communication with the fuel inlet conduit and the air inlet conduit. An ignition source is positioned within with mixing region for igniting the air/fuel mixture and beginning the pulse combustion process. An exhaust system removes flue gas containing products of pulse combustion. A portion of the flue gas produced during pulse combustion is then recirculated into the mixing region, air inlet, and/or an air decoupler.

Abstract: An improved multifuel heater having a means to provide a source of particte free combustion air to a fuel ignition chamber.

Abstract: A heat exchange assembly having a primary heat exchange element (20) intercommunicating with secondary heat exchange element (24) both housed in an enclosure (12). Hot combustion products from burner (28) are forced by fan (19) through the primary and secondary heat exchange elements in turn to an exhaust (31) whilst air to be heated is induced by fan (14) through enclosure (12). The flow direction of hot combustion products and their temperature drop along their flow path when considered with the flow direction of air being heated and delivered from outlet (16) of enclosure (12), ensures heat exchange characterized predominantly as counter-current and hence optimally efficient in consideration of the compact dimensions of the enclosure (12).

Abstract: A direct contact condensing heat-exchanger is provided with a water heat transfer medium in which combustion product gases are dispersed in finely divided bubble form against a relatively low hydrostatic pressure differential for efficient sensible heat and latent heat recovery purposes. In one actual application, a warm-air furnace system having a burner that produces combustion product gases as a heat source is provided with the novel direct contact condensing heat-exchanger as a seondary heat-exchanger that advantageously recovers both sensible heat and latent heat from the combustion product gases.

Abstract: The improved sectional high efficiency heat exchanger of the present invention comprises apparatus for directing hot flue gases backwardly and into a defined lower combustion chamber. Whereupon, such hot flue gases are directed forwardly in the lower combustion chamber through the upper part thereof. The heated air stream flow is then directed into and to the rear of a lower flue pass, and finally forwardly and to the front of the heat exchanger through an upper flue pass for exiting into a flue collector box. As a result of the above structure, during the burner-"off" cycle combusting gases from the pilot burner are permitted to flow upwardly along the front wall of the lower combustion chamber and into the upper flue passes, thus permitting the heat exchanger to obtain the benefit of the heat energy of the pilot burner gas during the burner-"off" cycle.

Abstract: An improved air heating apparatus and method of heating an air stream wherein the heating arrangement includes a heater housing with a combustion drum having a burner at one end thereof, the drum being disposed in spaced relation in the housing to extend longitudinally along the length thereof, a heat exchanger longitudinally extending in the space between the combustion drum and housing to receive combustion products from the combustion drum, an air stream blower positioned to pass an air stream over the heat exchanger in the space between housing and drum and to pass air from opposed ends of the combustion drum including the burner at one end to promote an extended burner flame substantially along the combustion drum length.

Abstract: An easily portable ventilating heater to supply either ambient fresh air or warm fresh air to utility workers while working in an underground utility installation. The ventilating heater comprises a blower unit and a heater unit. The blower unit can be used and operated without the heater being in operation. On the other hand, the heater cannot operate unless the blower unit is in operation. The ventilating heater has seveal safety features so that the heater automatically shuts down if the heater exceeds a pre-set temperature of about 200.degree. F., the inlet air flow is interrupted or the power or gas supply is interrupted. The ventilating heater automatically restarts once the heater temperature goes below the pre-set temperature and there is no interruption of air or gas flow or power. The heater uses liquid propane gas and the electrical system can be A.C. or D.C.

Abstract: A recuperative furnace system for space air and domestic hot water wherein a combustion product heat exchanger and a space air heat exchanger are each operated in counterflow manner. The dew point of the combustion products are elevated before entry into the combustion product heat exchanger and the water to be heated is introduced at the top at a temperature substantially below the natural dew point of the combustion products so that the fins of the heat exchanger are maintained in a substantially continuous wet state by enhanced condensation. The water thus heated is conveyed to a space air heat exchanger in counterflow to the space air so that the space air is heated to a relatively hot temperature (e.g. about 120.degree. F.) while still cooling the water to a low enough temperature (e.g. 90.degree. F.) so that the water can be looped back to the combustion product heat exchanger and still provide continuous wet operation.

Abstract: A compact, high efficiency heat exchanger for a fuel-fired forced air furnace has horizontally spaced apart inlet and outlet manifold structures which are innerconnected by a horizontally spaced series of vertically serpentined, relatively small diameter flow transfer tubes. Larger diameter inlet flow tubes are positioned beneath the balance of the heat exchanger, extend parallel to the transfer tubes, and have upturned discharge ends connected to the underside of the inlet manifold. The heat exchanger is configured so that its total vertically facing peripheral surface area is considerably larger than its total horizontally facing peripheral surface area, thereby signficantly reducing undesirable outward heat loss through the vertically extending furnace housing side walls upon burner shut off and increasing the overall efficiency rating of the furnace.

Abstract: A space heating appliance employing a radiant burner that burns a gaseous fuel and a plurality of heat pipes to transfer heat produced by the burner to the air to be heated. The appliance is adaptable for use in outdoor "packaged" units, together with an air conditioning system, for heating ventilation and air conditioning (HVAC) systems in commercial buildings, and is also adaptable for use in indoor residential or commercial applications.

Abstract: Basically the present invention in its most simple form or embodiment is directed to a heat exchanger which provides for at least two heat exchange surfaces and which has the combustion of the fuel, which generates the heat, take place within the heat exchanger rather than the heat of combustion being introduced into the exchanger from an external combustion chamber and wherein the flame is directed into an opening of a truncated cone which cone has a shape approximating the shape of the flame and wherein the tips or ends of the flame "play" on an arcuate surface which is in thermal energy transfer communication with fluid to be heated which is at the unheated or ambient temperature. Additionally, note that the fluid, air in the case of a hot air system, is introduced into the passages where heat exchange will take place, and directed toward the hottest region of the combustion chamber. That is, the coldest air comes into thermal contact with the hottest region providing for maxinum heat exchange.

Abstract: A burner assembly includes a burner housing having a combustion chamber defined therein and a fuel injection nozzle secured to the burner housing and communicating with the combustion chamber. A fuel control device is provided for controlling the amount of fuel flowing through the nozzle. The fuel control device includes a valve chamber including a bore and a valve seat and a needle valve adapted to reciprocate in the valve chamber. An adjusting device is provided for adjusting a range of motion of the needle valve in the valve chamber. The adjusting device includes a control rod secured at one end to the needle valve and a bimetallic assembly for regulating the motion of the control rod. The bimetallic assembly includes a pair of legs which are operably connected to the control rod and are exposed to the heat produced by the burner assembly.

Abstract: A carbon desorption heater (10) for use in a system for removing volatile organic contaminants from a carbon filter is disclosed as having a housing (30) in which a recirculating heating circuit (36) is provided with a recirculation blower (44) that moves the air past a burner (50) for flow through a first flow path (60) of a heat exchanger (58) with a portion of the recirculated air exhausted during each cycle of flow through an exhaust stack outlet (52). A delivery blower (64) within the housing (30) moves air through a second flow path (62) of the heat exchanger (58) for heating prior to delivery to a supply outlet (34). The heater includes a plurality of modules (90) that are sufficiently small so as to be shippable and subsequently securable to each other at the factory site where the heater is to be used.

Abstract: A forced hot-water heating system in which sensible and latent heat remaining in flue gases after contact with a primary heat exchanger is recycled into incoming cold air by a second heat exchanger. The heater, humidified intake air is then directed to a fuel burner, and reduces the amount of fuel necessary to achieve a given amount of heat exchange at the primary heat exchanger at normal operating return-water temperatures.

Abstract: A fuel-fired, condensing type forced air heating furnace is provided with an improved hot combustion gas-to-air heat exchange system which includes a generally drum-shaped primary heat exchanger having an outlet end connected to a first end of a transfer manifold whose second end is connected the inlet end of a fin-and-tube type secondary heat exchanger which is spaced laterally apart from, faces, and extends generally parallel to the primary heat exchanger. A radial discharge fuel burner end portion is coaxially positioned within an inlet end of the primary heat exchanger and, during furnace operation, a draft inducer fan draws burner combustion gases sequentially through the primary heat exchanger, the transfer manifold and the secondary heat exchanger while air to be heated is flowed externally over these heat transfer elements.

Abstract: A forced-air furnace for burning gas or fuel oil or waste oil utilizes relatively few components and effectively heats air for space-heating purposes. The furnace includes a substantially enclosed, elongated housing having an air intake and an air discharge vent and a hollow elongated heat exchanger/combustion chamber which is supported within so as to extend axially along the housing. The furnace also includes a fuel burner assembly supported at the discharge end of the housing for directing a flame and attending combustion products directly into the heat exchanger so that the inner surface thereof absorbs heat generated thereby and so that no part of the flame impinges upon the heat exchanger. Heat transfer from the combustion products to the heat exchanger is enhanced by a pair of removable platen-like baffles mounted within the heat exchanger.

Abstract: In an inducted draft, fuel-fired furnace a flow restriction in the external exhaust flue is detected, and the furnace burners responsively deactivated, by a thermal sensing switch mounted in a spaced relationship with a small flow opening formed in a sensor housing externally secured to the inducer fan outlet section over a wall opening therein. During normal burner combustion product discharge flow through the exhaust flue, a small vane within the inducer fan outlet section creates a venturi therein which draws ambient air within the furnace housing across the temperature sensing switch and into the fan outlet section through the sensor housing opening. The temperature of this ambient air is below the switch set point so that continued burner operation is permitted.

Abstract: A pulse combustion fired space heater is disclosed. The heater has an exterior cabinet enclosing an interior housing having a pulse combustion burner mounted therein. The burner includes a plurality of generally flat elements which cooperate with the interior housing to provide a tortuous path for air circulated through the chamber during heat transfer. The circulating air pressurizes the interior housing to enhance uniformity of heat transfer and suppress structural vibrations.

Abstract: To inhibit internal heat exchanger corrosion, the products of combustion from a standing pilot flame in an induced draft, fuel-fired furnace are prevented from migrating through the heat exchanger during idle periods of the furnace by flowing the products of combustion upwardly through a small vent tube into the outlet section of the draft inducer fan, and then into an external exhaust stack, thereby bypassing the heat exchanger. During operation of the draft inducer fan a negative pressure is maintained within the vent tube, to prevent combustion gas outflow therethrough which might otherwise snuff out the pilot flame, by a venturi structure positioned within the draft inducer fan outlet section adjacent its juncture with the vent tube.

Abstract: A furnace utilizing, in the upper portion of its cabinet, a blower acting downward through a separator opening to circulate room air past a combustion chamber whose gases flow upward through a sideward-positioned board radiator member which reaches up to the flue. A substantial increase in efficiency results from drawing the combustion gases out of the combustion chamber at the side opposite to the lower end of the broad radiator member, and interposing therebetween, directly beneath the separator opening, a plurality of tubes which serve as an intermediate heat exchanger. A still greater increase in efficiency is achieved by utilizing, instead, a finned tube heat exchanger across and beneath said separator opening; its heat transfer may be so great as to result in condensation of water vapor in the combustion gas. To purge this, a motorized inducer-blower is used in the inlet air system, driving the condensate through the finned tube heat exchanger to an appropriate drain.

Abstract: An electrical connection device for electrically operated components of heaters, especially vehicle heaters, in which block-shaped plug parts are molded on the lines coming from the components. The block-shaped plug parts are grouped side-by-side into a unit and a cap is attached to this unit. The cap has connection parts which are designed to be complementary to connection parts of the block-shaped plug parts so that a plug-in electrical connection is formed when the cap is mounted to the unit. Accoding to a preferred embodiment, the block-shaped plug parts are placed directly on the outside of a housing of a heater and they are connected with each other to form the unit with the help of interlocking connections and the cap. In another embodiment, the block-shaped plug parts are grouped into a unit and held together by a support having a pocket for each block-shaped plug part which is fastened to the heater by a holder.