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.

Abstract: An automatic flue gas heat recovery system for supplementing or replacing a conventional, separate hot water system. In the example described, the heat recovery system is applied to a pizza restaurant where large quantities of heat energy are normally wasted up an oven chimney stack, and large quantities of hot water also are required for restaurant operations. An electric motor driven pump circulates water in a closed loop between a storage tank and a heat exchanger tube located in the oven chimney stack. A thermostat control automatically starts the pump when the oven heats the chimney stack to an effective water heating temperature. When temperature in the storage tank reaches a predetermined maximum, the thermostat control stops the pump, opens a drain valve, and dumps water quickly and completely from the heat exchanger tube. Three different embodiments are shown and described illustrating systems with one or more storage tanks and one or more pumps.

Abstract: Flue gases from a glass-melting furnace, after passing through an elevated recuperator, descend through a vertical cooling column into a horizontal convective boiler before being exhausted into a smokestack. Entering water, circulating essentially in counterflow to the flue gases, is preheated in an exit compartment of the boiler and passes via a flow regulator into the main boiler chamber and thence into a bank of vertical pipes on the periphery of the column. On rising through these pipes, the water is partly converted to steam which is superheated in an entrance compartment of the boiler before being fed to a load, the remaining water being returned to the boiler chamber.

Abstract: An economizer construction for use in recovering heat from flue gases is disclosed including a housing with a flue gas passage therethrough, a helically wound heat transfer coil positioned in the flue gas passage for placing a heat transfer fluid in a heat exchange relation with the flue gases passing through the flue gas passage where the heat transfer coil defines a generally vertically extending central opening therethrough, and a soot blower assembly with an elongate soot blower lance rotatably mounted in the coil central opening for directing a pressurized cleaning fluid over the heat transfer coil to periodically clean it. Different embodiments of the rotary mounting of the soot blower lance are disclosed. Also, different embodiments of the drive means for rotating the soot blower lance are disclosed.

Abstract: An apparatus for the recovery of heat from waste gases is disclosed. The apparatus generally comprises a heat recovery coil which is located above the combustion chamber of a furnace and in the path of waste gases psssing through a flue, a circulation pump and an expansion manifold. The apparatus is equally useful in new as well as retrofitted applications.

Abstract: A boiler economizer includes a first heat exchanger disposed in a boiler flue and a second heat exchanger which is external. Boiler feedwater is delivered in series to the first and second heat exchangers before passage to the boiler. A flow controller directs a first portion of the boiler feedwater directly to the first heat exchanger and a second portion is first delivered through the second heat exchanger where it is passed in a heat exchange relation with the feedwater exiting the first heat exchanger. The flow controller is positioned by a temperature transponder which is responsive to the temperature of the discharge flue gases and the feedwater entering the first heat exchanger.

Abstract: A furnace with a combustion compartment and a heat exchanger compartment connected by a channel having a secondary air inlet for efficiently burning wood and absorbing the heat of combustion.

Abstract: In the boiler plant the flue gases coming from the firing space undergo division into at least two part-currents which are cooled to different degrees by giving up heat to a heat exchange medium and are then mixed together partly for producing a gas current with a desired temperature dependent on the rates of mixing of the two part-currents. The mixed current is then taken up by a heat user. Parts of the flue gases not going to the heat user are run through all heat absorbers of the system as far as the off-gas stack. The amounts of the part-currents of flue gases, used for forming the gas current with the desired temperature of mixing, are controlled dependent on the mixing temperature.

Abstract: A cooling device for use in tubular hot gas conduits which are made up of a plurality of longitudinally arranged side by side abutting pipes includes a plurality of registers arranged in spaced relationship along the length of the pipe and extending into the pipe from one side thereof into closely spaced arrangement in respect to the opposite side. The registers each include a plurality of U-shaped pipes which are interconnected and arranged in the direction of flow and which are connected externally of the hot gas conduit through respective inlet and outlet headers.

Abstract: A stack exhaust heat recycling system utilizing the heat content of exhaust gases passing through a smoke stack to the ambient atmosphere. The stack includes an inner shell defining a passage to carry the exhaust gases without restrictive draft. Surrounding this shell in any desired configuration is tubing carrying fluids (liquids, gas or oils). Surrounding the tubing is an intermediate shell, insulation and an outer shell. During the passage of the fluid through the tubing, transfer of heat occurs from the gases to the fluid so that its temperature is elevated for use, e.g., as hot water, thus eliminating or supplementing a hot water heater. Other uses requiring elevation of the temperature of water or gas may be similarly utilized.

Abstract: A heat exchanger coil disposed in a furnace chamber or duct to absorb heat from the furnace to increase the temperature of water passing through said coil from a cold water source to a hot water heater or storage tank is disclosed. An additional feature includes a second heat exchanger coil disposed between the cold water source and the furnace heat exchanger within the confines of a building to absorb heat from the ambient surroundings. An insulated coiled storage unit disposed downstream of the furnace heat exchanger to provide a quantity of additional preheated water to the water heater and a spurge tank overheat and overpressure relief unit for the system is also disclosed.

Abstract: A space heater with a heat recovery system in which the exhaust gases from the hot air furnace are passed through a heat exchanger in which a set of water heating coils is disposed. The set of coils is connected to a hot water holding tank which is in turn connected to a bank of heat exchanger coils in the heated air outlet of the furnace. A damper is provided in the exhaust pipe of the furnace and a pipe connects the exhaust pipe on the anterior side of the damper with the heat exchanger, and a pipe connects the chamber with the exhaust pipe on the posterior side of the damper. A pump is provided for circulating the water between the first set of coils and the holding tank, and a fan forces the air form the exhaust pipe through the chamber in the heat exchanger. The pump and fan are controlled by a switch responsive to the operation of the furnace. The holding tank may be used to heat water supplied to a hot water heater of a hot water supply system.

Abstract: A modular, heat recovery system is provided for use with furnaces, boilers, and the like where otherwise waste exhaust heat is utilized to heat water for home or apartment use. This system includes a plurality of modular pipe loop sections interconnected with one another and mounted in proximity to the stack of the furnace. Each section includes several courses of longitudinally extending U-shaped loops supported on a common perpendicular pipe section at one end and which forms part of a supply line for other sections. Each section is provided with unions and valves by means of which an entire section maybe disconnected for repairs from the other sections without interruption of the operation of the other sections. A drip pan is provided at the lower end of the system to prevent water leaks from dripping onto the furnace.

Abstract: A preheating device for hot water heaters which employs hot gases of combustion from the flue to preheat incoming cold water and to continually preheat water stored in the water tank by natural recirculation. Use of the device provides for increased fuel efficiency because hot combustion gases from the heat source are used for warming of water before venting to the atmosphere, the result being an average increased temperature within the tank so that lesser amounts of fuel are required to reach any desired hot water temperature.

Abstract: An improved arrangement for preheating feedwater in a steam boiler system prior to the feedwater entering a fuel economizer in order to prevent corrosion due to condensation of flue gas in the fuel economizer and in the exhaust of the boiler system. The feedwater, prior to entering the fuel economizer, is heated in a preheater with a portion of steam from a boiler. The amount of steam entering the preheater is regulated by two temperature control valves. A first temperature control valve is regulated by the temperature of the feedwater prior to entering the fuel economizer. A second temperature control valve is regulated by the temperature of the flue gas in the boiler exhaust stack.

Abstract: A device for the reduction of heat losses due to flue gasses in boilers of the type having a flue and which are operated with oil or gas and wherein the boiler has a heat exchanger in the flue serving to reduce the temperature of the flue gases. A heat pipe having a U-shaped configuration is disposed in the flue with the heat exchanger being positioned between the pipe ends, and the warm side of the heat pipe is between the boiler and the heat exchanger.

Abstract: A heat exchanger with a housing defining a main fluid flow passage therethrough and a tube bundle access opening to the fluid flow passage, a tube bundle unit removably positioned in the housing in the fluid flow passage through the access opening, and a cover for removably closing the access opening so that heat exchange fluid flowing through the tube bundle unit is in a heat exchange relation with the fluid flowing through the housing main fluid flow passage around the tube bundle unit. Also shown is an economizer for a stream boiler incorporating a heat exchanger.

Abstract: An attachment or, accessory water heater being installed in any furnace flue, or pipe giving off an exhaust heat. When installed in a flue or pipe and connected in conjunction to any type self-sufficient water heater tank. It is the purpose of this invention, to use the heat which escapes up the flue from the furnace during operation. Thus eliminating in most cases, and drastically reducing in others, the need for additional energy, which is normally used to heat water. The accessory heater is essentially a condensed unit, which divides water into multiple and smaller parts, comprising a conduit of two sizes, being formed and shaped into condensed spiral coils, and connected to rings or headers, and circulating water through the unit and back to the tank, by means of convection or pump.

Abstract: The invention as disclosed in the following specification, relates to a heat exchanger, having tubes fitted into plates, that exchange heat from a gas passing thereover to fluids passing through the tubes. The heat exchanger is particularly adaptable to boilers having fire tubes and other types of boilers wherein the heat applied to the tubes is circulated and then exhausted. Prior to exhaust, the heated gas is passed over the plates in a duct. The tubes in the plates are used to pick up the heat from the exhaust gases by means of the feed water passing through the tubes, or the tubes can be used to directly heat other fluids, such as oil and service hot water. A damper is placed over the normal exhaust gas flue in conjunction with a second damper or duct control system whereby an exhaust fan on the downstream side of the heat exchanger duct provides a constant draw to allow the boiler to operate within its normal pressure ranges.

Abstract: The present invention discloses an economizer for absorbing heat of combustion products, wherein the surfaces of a series of continuous tubes extended through an exhaust gas pipe or duct are lined with glass pipes, the clearance between the exhaust pipe or duct wall and the tubes extended therethrough is sealed with gaskets, and water is circulated through the tubes.

Abstract: A dust collector of the gravity separation type is combined with a heat exchanger to provide a dust collector/air preheater, or a dust collector/economizer, depending upon the heat exchange fluid used, suited for usage in a system or process for discharging and exchanging heat with exhaust gases from a boiler.

Abstract: Apparatus interposed in a smoke flue between a furnace and a chimney for recovering energy from smoke and heating water therewith. A tank contains a volume of water to be heated. A water inlet and a water outlet supply cold water to the tank and discharge heated water. A plurality of heat exchanging tubes extends through the interior of the tank such that the ends communicate with opposite exterior surfaces of the tank or extend outwardly therefrom. A plurality of sleeves, one for each tube, has an outside diameter slightly less than the inside diameter of the tubes such that each sleeve is positioned within one of the tubes in concentric manner and sealed to the ends of the tube to define an annular air space there-between. Expanding and reducing elements provide gaseous communication between the flue and the plurality of sleeves.

Abstract: A water heating system includes a boiler which is connected with a source of water supply for receiving water under pressure. An exhaust flue is connected to the boiler for the discharge of gaseous products of combustion. A pair of concentrically arranged coils is positioned within the exhaust flue and is connected with the conduit feeding water to the boiler. A recycle loop is thus provided for withdrawing a minor portion of the water being fed to the boiler and for recycling same at a higher temperature to the feed conduit. The water circulates within the loop by natural connection.

Abstract: An economizer for extracting heat energy from low temperature flue gases while simultaneously removing therefrom contaminates consisting chiefly of oxides and oxygen acids of sulfur. The economizer includes a plurality of heat exchange tube assemblies, each of which comprises concentrically spaced inner and outer tubes of different materials. The spaces between the concentric tubes are filled with graphite which remains in heat conductive contact with the inner and outer tubes while accommodating their differential rates of thermal expansion and contraction upon heating and cooling. In the preferred form of the invention, the outer tube is made of low expansion borosilicate glass, while the inner tube is of copper. The flue gases flow transversely to the tube assemblies while water is rapidly circulated through the copper tubes in order to absorb efficiently the heat conducted sequentially through the glass, graphite and the copper materials.