Abstract: A convection oven comprises a heating compartment, a burner for effecting combustion of gas, a heat exchanger for conducting therethrough the products of combustion of gas initiated at the burner, first and second blowers for blowing air past the heat exchanger and into the heating compartment for heating the compartment, upper and lower blowers each having an inlet through which air is drawn into the blowers from a common side of the heating compartment for recirculation past the heat exchanger, and the heat exchanger having first and second outlets for the combustion products respectively disposed in front of the inlets of the upper and lower blowers. Each outlet is located to direct the combustion products towards a lower region of the inlet of the respective blower.

Abstract: The invention relates to a device for cooling of the furnace chamber (4) in a hot isostatic press by means of devices (7, 8) for circulation of a coolant in the furnace chamber (4), the coolant having a temperature which is lower, but not considerably lower, than the temperature of the articles.

Abstract: A gas fired convection cooking oven is provided with an improved air delivery and heat exchange structure for creating within the oven's cooking chamber a recirculating flow of heated air to cook food items supported therein. The structure includes a combustion box adapted to receive hot products of combustion from a gas burner, and extending into the cooking chamber through a lower portion of a vertical boundary wall thereof. Removably secured to the combustion box, and extending upwardly along the inner side of the boundary wall is a hollow baffle structure having a front mixing chamber communicating with the interior of the combustion box through spaced apart hollow legs with a discharge opening formed therebetween. Perforated skirt walls extending rearwardly from the mixing chamber define with the boundary wall a fan chamber which surrounds a motor-driven centrifugal fan impeller supported on the inner side of the boundary wall.

Abstract: An internal heat exchange tube for cooling work within an industrial furnace is positioned to extend within the furnace and is closed at its axial end which is inside the furnace. Within the tube is an open ended, thin wall inner tube formed in the shape of a helical coil. Water introduced into the inner tube distributes thermally induced, circumferential stress gradients about both tubes to prevent tube bending while achieving fast cooling of the outer tube.

Abstract: A method for circulating a gas in an autoclave which comprises a pressure container (A) having a wind tunnel (7) in which moldable materials (1) are placed and the gas is circulated by a blow fan (33), the pressure container (A) being sealably closed by a door, the layers of each of the materials (1) are compressed, heated, adhered together, and set in the pressure container (A) producing swirling of the gas coming out of an outer duct formed between the inner face Aa of the pressure container (A) and the wind tunnel (7) by guide blades (H), diverting the gas at the inner face (2a) of the door (2), and directing the diverted gas to flow through the inside (7b) of the wind tunnel (7) with the swirl. The apparatus for circulating gas has guide blades (H) for swirling the gas going out of the outer duct (7a) provided in the outer duct, whereby the gas is diverted at the inner face (2a) of the door (2), and is directed to flow through the inside (7b) of the wind tunnel (7) with the swirl.

Abstract: An apparatus for maintaining a crystal at a precisely controlled operating temperature over extended periods of time without significant thermal degradation of the crystal. The apparatus has thermally conducting walls. The walls define an inner hermetically sealed chamber for the crystal. Input and output windows are hermetically sealed to the input and output ends of the chamber. The inner surfaces of these windows are maintained at the operating temperature of the crystal to prevent fogging of the windows. Flexible thermal conducting layers are used between the crystal surfaces and the walls of the chamber to achieve uniform and continuous thermal contact therebetween, without mechanical stress to the crystal. The structure provides fast thermal response, controlled temperature in the crystal interaction region and stability of operation over extended periods of time. In one preferred embodiment, the crystal is held in suspended position within the chamber between a pair of spring-loaded plungers.

Abstract: A low cost, improved convective heat transfer furnace is disclosed which includes a cylindrical casing to which is attached blanket insulation and the casing is closed at its ends to define a closed end cylindrical furnace enclosure. An annular fan face plate is positioned within the enclosure to define a pressure zone on one side and a work zone on the other side. A paddle wheel fan in the work zone develops a large mass of circumferentially swirling wind which is initially formed as a stationary swirling mass without an axial force component but which under pressure travels axially in the form of a swirling annulus through the non-orificing annular space. The under pressure zone established by the central opening in the fan face plate causes the swirling wind annulus in the work zone to expand radially inwardly and uniformly impinge the complete surface of the work in an effective heat transfer manner before being recirculated back to the pressure zone.

Abstract: Infrared (IR) strip heaters are juxtaposed with convection heaters for simultaneous, independently controlled, combined radiant/convective heating in a conveyor oven. Apertured plates with portions transmissive to IR radiation are interposed between a lower combined heating unit and the cooking path. The IR heaters are preferably gas burners with porous, ceramic or metallic elements, the burners on opposite sides of the cooking path being independently controllable to vary the heat transfer rate to opposite food surfaces. Symmetrical placement of the IR heaters in opposed pairs facilitates use of the conveyor oven as a half oven. An auxiliary burner exhausts directly into the convection air and is cycled on and off to maintain a set temperature during normal operation.

Abstract: An enhanced, air-flow convection oven is disclosed, comprising an oven chamber liner circumscribed by a thermally insulated outer oven shell with a heat source in a combustion chamber between the shell and the liner. Hot air flows from the combustion chamber and into a uniquely constructed blower wheel assembly. The blower wheel assembly has a concave central plate configuration which creates a negative pressure behind the blower wheel assembly, inducing a flow of hot air from the back of the blower wheel assembly into the blower wheel assembly as the wheel rotates. This hot air is mixed with air from within the chamber to produce uniform heating throughout the chamber.

Abstract: Apparatus for producing honeycomb panel comprising a heating chamber isolated by a wall from outer air and a plurality of drawout trays capable of being individually inserted into and withdrawn from the heating chamber through a plurality of openings formed in the wall. Each of these drawout trays has a work accommodating chamber connected to a vacuum source, a top opening of which can be hermetically closed by a flexible sheet that can be opened and closed. Also each of the drawout trays has block plates at the front and rear ends for closing the opening in the wall at every terminal positions when inserted and withdrawn.

Abstract: A cooling system for a processing furnace provides improved cooling efficiency in a more compact arrangement than known furnace cooling systems. In the system a blower is situated within the cooling gas plenum but has its intake exterior thereto. The plenum wall and the furnace outer wall define a recirculation channel which is relatively large and free of obstructions. Heat exchanger coils are disposed within the recirculation channel adjacent the blower intake thereby providing a less restricted flow path for the cooling gas.

Abstract: A fuel fired heat treating furnace having an imperforate inner shell for containing a work load in isolation. The shell is made of a refractory material which provides a good heat exchange from the outside to the inside. A multiplicity of hot gas streams is directed under pressure against the outside of the shell by means of a circulation system which includes a plenum, a fan within the plenum and a plurality of apertured distributor tubes extending from one end of the shell to the other. Fuel burners exhaust combustion gases into the system on the discharge side of the fan where the gases mix with returning gases from the intake side of the fan and are fed into the distributor tubes.

Abstract: A gas fired convection cooking oven is provided with an improved air delivery and heat exchange structure for creating within the oven's cooking chamber a recirculating flow of heated air to cook food items supported therein. The structure includes a combustion box adapted to receive hot products of combustion from a gas burner, and extending into the cooking chamber through a lower portion of a vertical boundary wall thereof. Removably secured to the combustion box, and extending upwardly along the inner side of the boundary wall is a hollow baffle structure having a front mixing chamber communicating with the interior of the combustion box through spaced apart hollow legs with a discharge opening formed therebetween. Perforated skirt walls extending rearwardly from the mixing chamber define with the boundary wall a fan chamber which surrounds a motor-driven centrifugal fan impeller supported on the inner side of the boundary wall.

Abstract: An improved heat transfer arrangement for use in a unique multi-function, industrial heat treat furnace which employs a sealed, closed end, heat exchanger shell member containing the work. The heat transfer arrangement includes a totally contained, internal recirculation system which develops an especially configured annular jet stream that produces highly efficient, convective heat transfer with the shell member. After heat transfer between the entrained gases in the jet stream with the shell member has occurred, the jet flow is reversed at one end of the shell and impinged against the workpiece, the spent stream being reformed into the annular jet at the opposite end of the shell member.

Abstract: A gas-fired convection oven comprises a cooking cavity having a centrifugal fan mounted on a rear wall thereof. A vertical shroud mounted adjacent to the fan forms a narrow heat exchanging chamber within the cavity. A heat exchanger comprising a generally U-shaped hollow tube extends within the heat exchanging chamber and is provided with outwardly directed jets on the leg portions thereof. A power jet burner surrounded by a secondary air passageway conduit communicate with an inlet into the heat exchanger. Means for baffling secondary air at the inlet to the heat exchanger provides for generally balanced flow of combustion products within both legs of the heat exchanger facilitating energy efficiency in the heating of the cooking cavity.

Abstract: An internal gas generator in combination with a standard heat treat furnace is provided for producing either an endothermic product gas or a purge gas. The generator includes a reaction tube containing alternating packed beds of a highly active catalyst and inert heat transfer particulates. The reaction tube is surrounded by an elongated tubular heating element which heats the reaction tube, the combination producing an acceptable product gas in a small arrangement suitable for retrofit applications to existing furnaces. A flanged mounting permits the reaction tube to be easily removed for standard replacement in the event of catalyst poisoning and the like.

Abstract: An improved heat transfer arrangement for use in a unique multi-function, industrial heat treat furnace which employs a sealed, closed end, heat exchanger shell member containing the work. The heat transfer arrangement includes a totally contained, internal recirculation system which develops an especially configured annular jet stream that produces highly efficient, convective heat transfer with the shell member. After heat transfer between the entrained gases in the jet stream with the shell member has occurred, the jet flow is reversed at one end of the shell and impinged against the workpiece, the spent stream being reformed into the annular jet at the opposite end of the shell member.

Abstract: A heat treatment apparatus which comprises a treatment chamber formed with heat insulating walls, a graphite heater installed in the treatment chamber, a gas supply port supplying non-oxidizing gas to the chamber and an exhaust port for carrying gas out of the chamber. At least a part of the inner side of the heat insulating walls is made of graphite group material of bulk density of not less than 0.3 g/cm.sup.3. The ratio of the outer surface area of the graphite heater (Ah) to the surface area of the chamber-facing side of the heat insulating walls (Ai), Ah/Ai is within the range of 0.1-0.4, and the relationship between the surface area of the graphite group material (Ar) and (Ah) is Ar>Ah. By this structure, the temperature of the heater to be set for heat treatment of workpieces can be decreased, and the life spans of the heater and the heat insulating walls can be increased.

Abstract: A process for high efficiency hot isostatic pressing in a hot isostatic pressing treatment for sintering or densifying a ceramic or metallic workpiece in a high temperature and high pressure gas atmosphere, which includes preheating the workpiece outside a high pressure vessel prior to the hot isostatic pressing treatment, transferring the preheated workpiece as surrounded with the gas in a hot state into the high pressure vessel, then treating the workpiece at high temperature and high pressure in a gas atmosphere, thereafter taking out the workpiece from the high pressure vessel together with the gas atmosphere, then cooling the workpiece if necessary, and subsequently taking it out from the gas atmosphere, as well as an apparatus for practicing the above-noted process, wherein a treating chamber for effecting the hot isostatic pressing treatment is covered with a hermetic casing, and at least one valve mechanism capable of providing communication and cut-off between the interior and exterior of the treatin

Abstract: The disclosure relates to a system for removing binder from "green" bodies wherein debinding action takes place substantially uniformly throughout the sytem for large load as well as for small loads. This result is obtained by providing a plurality of shelves for holding the parts and providing turbulent atmosphere flow across all shelves with recirculation taking palce over a water fall in the system to provide both a water saturated atmosphere and removal of binder from the atmosphere and system simultaneously.

Abstract: A gas convection oven includes a heating chamber having a gas combustion chamber formed therein and a blower positioned within the combustion chamber for circulating air through the heating and combustion chambers. The blower defines a low pressure inlet centrally of the combustion chamber for receiving air from the heating chamber and forcing it through the combustion chamber back into the heating chamber around the outer edges of the combustion chamber. A gas burner extends into the combustion chamber and includes a distally-mounted diverter for dividing and directing flame and combustion products into two different directions. A bifurcated heat exchanger defines first and second tubular passages which are aligned with and encompass the blower and define inlets aligned with the two different directions for receiving the combustion products from the burner.

Abstract: A bakery oven, of the type employing a continuous spiral conveyor for carrying goods to be baked through an oven enclosure, employs an air distribution system to direct heated air from near the top wall of the oven enclosure to a plenum chamber, and from there through an air distribution network to at least certain ones of the tiers of the spiral conveyor. Preferably, heater elements are disposed beneath alternate ones of the tiers of the conveyor system within the oven enclosure, while the air distribution pipes are disposed beneath the remaining tiers. This arrangement serves to decrease fuel consumption for the burners, thereby increasing productivity, and further serves to decrease the stratification of heat layers within the oven enclosure, thereby providing uniform baking conditions throughout the oven enclosure.

Abstract: A continuous heat treating furnace for heat treating a ferrous metal work in a protective atmosphere, including a furnace separated into a charge chamber and a heat treating chamber by a partition door and provided with a transport device for transporting the work. A first heating device, a recirculating fan and a gas purge device are provided in the charge chamber, while a second heating device is provided in the heat treating chamber supplied with the protective atmosphere, whereby the work is preheated through convectional heat transfer in the charge chamber simultaneously with high-temperature purging of the charge chamber and then, is heat treated under the protective atmosphere in the heat treating chamber.

Abstract: An ingot furnace pusher furnace includes a fixed baffle assembly suspended from a furnace top wall. The baffle assembly includes a horizontal top baffle plate and a bottom baffle sheet disposed below the top plate. The bottom baffle sheet consist of a center portion and a pair of first and second upwardly sloping end portions connected to the center portion. The center portion is positioned substantially parallel to an upper suface of a center portion of the ingot. A first deflection baffle is rotatably supported at its one end by a pipe to the baffle assembly adjacent the first sloping end portion. A second deflection baffle is rotatably supported at its one end by a pipe to the baffle assembly adjacent the second sloping end portion. Linkage devices are connected to the other ends of the first and second deflection baffles for moving the same between a horizontal position parallel to the upper surface of the ingot and an acute angle position relative to the horizontal position.

Abstract: Apparatus for cooking-dehydration and sterilization-drying of organic wastes, comprises a chamber (1) heated by a double walled enclosure (2) that communicates with fire tubes (3), the enclosure (2) receiving hot gases from a firebox (4). The hot gases pass through conduits (5) to diffusion nozzles (6) immersed in the products (7) to be dried. Some of the combustion gases are recycled by a ventilator (8) via a conduit (9) and a cyclone (10) to the firebox (4). The ventilator (8) draws in fresh air through a preheating heat exchanger (11) that is heated by the combustion gases which are then vented.

Abstract: A fluidized bed furnace includes a furnace housing having an outer shell. A furnace base and an outer top plate are secured to the respective lower and upper ends of the housing. A vertical retort has an opened upper end and an opened lower end. The retort is arranged in an opening formed in the outer top plate and extends downwardly into the center of the housing. Heat insulating material is disposed between the outer shell and the vertical retort. A retort base assembly is used to close the lower end of the retort. An upper support device is formed integrally with the retort at its upper end for supporting the vertical retort on top of the outer top plate so as to permit downward growth only during thermal expansion. A lower support device is interposed between the lower surface of the retort base assembly and the upper surface of the furnace base which supports substantially all the weight of the retort, the weight of the load of fluidizable media and the weight of a load of material to be heat treated.

Abstract: For recovery of heat, aggregates of metallic articles through which gas can flow are carried in a succession of baskets through a preheat zone, a treatment zone and a cooling zone of a heat treatment furnace and a heat transfer gas is constrained to flow vertically through the baskets in succession, beginning with the basket farthest advanced through the furnace, so far as concerns the basket in the cooling and preheat zone, the baskets having bottoms through which the gas can flow into or out of the aggregates. The heat transfer gas flows directly from the cooling zone. This may be done through the treatment zone where it may pick up additional heat. Heat may be removed from the heat transfer gas in a return circulation path outside the furnace.

Abstract: An improved air delivery system is provided for an impingement food preparation oven including a plurality of air ducts disposed in a cooking chamber, a plenum connected to the air ducts, and a scoop-type fan disposed in a backwall opening of the plenum to provide a flow of heated air smoothly and uniformly through the plenum into the air ducts. The fan device includes a plurality of tear-drop shaped blades, wherein each blade has a leading edge portion that tapers to a point in the direction of rotation and a trailing row portion at a given pitch angle for forcibly moving the flow of air in an axial direction toward the plenum front wall. The plenum front wall has a plurality of openings connected to the duct members, and a centrally disposed conical surface projecting outwardly toward the fan so that the axially directed flow of heated air from the fan is smoothly and uniformly directed by the conical surface the plurality of air ducts so as to provide a uniform cooking temperature in the cooking chamber.

Abstract: An oven and method for cooking food products. The oven comprises an elongated housing having an inlet for food products to be cooked in the oven and an outlet for emitting cooked food product from the oven, together with means for heating a gaseous cooking medium in the housing for cooking the food products therein, and a plurality of vertically tiered endless conveyors for passing the food product back and forth through the housing during the cooking process, whereby an oven taking less floor space for a predetermined flow path extent of cooking various food products, is provided.

Abstract: A bakery oven, of the type employing a continuous spiral conveyor for carrying the goods to be baked through the oven enclosure, employs an air distribution system to direct heated air from near the top wall of the oven enclosure to a plenum chamber, and from there through a pipe distribution network to at least certain ones of the tiers of the spiral conveyor. Preferably, heater elements are disposed beneath alternate ones of the tiers of the conveyor system within the oven enclosure, while the air distribution pipes are disposed parallel to and beneath the remaining tiers. This arrangement serves to decrease fuel consumption for the burners, thereby increasing productivity, and further serves to decrease the stratification of heat layers within the oven enclosure, thereby providing uniform baking conditions throughout the oven enclosure.

Abstract: An improved ingot pusher furnace having a base carrying a plurality of laterally slidable shoes with upper surfaces smoothly tapering into said base. A pair of side walls is connected to said base with a top wall connected to said side walls to define a heating enclosure. A pair of end walls are connected to the base, side walls and top walls, each of the end walls having a vestibule, including a pair of double doors therein. A baffle assembly is movably connected to the top wall to be held in spaced proximity from an ingot to be heated.

Abstract: Industrial oven providing air recirculation for heat treatment processes having temperature uniformity within a charge to be treated, including oven walls, spacers disposed between the oven walls for supporting the charge at a distance from the oven walls defining a space therebetween and for allowing a recirculated hot air flow around the charge from all sides, and elements disposed in the space between the charge and the oven walls for influencing the air flow.

Abstract: A fiber treatment oven is disclosed in which hot gas is flowed parallel to and between fiber pathways within the oven to reduce deflection and breakage of fibers and to reduce end-to-end temperature variations in the oven. Hot gas is emitted centrally of the oven and flows toward ends of the oven. Preferably, an additional, generally tubular stream of hot gas is emitted centrally of the oven and generally surrounds and envelopes the fiber pathways to reduce side-to-side temperature variations.

Abstract: An oven with air convection combustion, particularly for bakehouses (bread, pastries, cakes), to achieve considerable economy of energy and to improve efficiency has primary and secondary air circuits sealed and closed, the secondary air being heated in ducts surrounding the fire-box and exhaust conduits and admitted into the baking chamber through adjustable nozzles. The cooled secondary air leaving oven is recycled by the a turbine. A vapor generator is formed from metal tubes extending into the exhaust gas conduit and the vapor is fed to a ramp pierced with calibrated holes disposed vertically in the baking chamber through which it is disposed into the chamber after being saturated by a water injector.

Abstract: A gas-fired convection oven for processing food, for example, having a fan for moving air along a circulatory path over, along and about the food to be processed. A package type gas burner outside the oven is directed into a heat exchanger tube of substantial length extending into the oven. High-temperature exhaust gases are discharged from the burner to be directed through the heat exchanger into the circulatory path of air flowing through the convection oven. Relatively proximate the burner the heat exchanger has a linear portion that is of elliptical cross section, and that portion is oriented with respect to the outlet of the convection blower and walls of the convection blower chamber to draw air over substantially the entire surface area of such portion for maximum cooling/heat exchange function with respect thereto.

Abstract: Apparatus adapted to deliver a temperature-controlled gas from a common plenum to at least two thermal treatment zones is provided. The subject apparatus is adapted to direct columnated jets of a temperature-controlled gas so as to impinge on at least one surface of food products passing through such zones, and is further adapted to convey food products through such zones in multiple passes in which the food products are subjected to different thermal energy transfer rates in at least two of such zones.

Abstract: Apparatus for preheating scrap material, e.g. scrap metal, comprises heaters, such as air preheaters, scrap containers and air or gas conduits for conveying heated gas from the heaters to the scrap container(s) and back from the scrap container(s). The apparatus is characterized in that the conduit to the scrap container(s) is provided with valve means for diverting the flow of hot air or gas to the container(s), for example during replacement of container(s).

Abstract: A furnace for heating steel articles and so on without oxidation and decarbonization. In the furnace, non-oxidation gas atmosphere with or without cementation characteristics is produced and regenerated by subjecting the air to carbon elements and heat at a reaction chamber provided within the furnace or closely thereto, and the gas atmosphere is circulated through a substantially closed circuit with the said reaction chamber connecting outtake and intake openings of the furnace.

Abstract: A furnace for heating particulate material comprises an air-tight shell and a heat insulating lining which define a hollow shaft. Electrical resistance heating elements spaced along the length of the hollow shaft adjacent the insulating lining. A baffle system supported within the shaft promotes heating by radiation and convection. The baffle system has side supports vertically positioned within the shaft, a plurality of inner trays each defining pairs of sloping surfaces joined at a ridge, and a plurality of outer trays each defining a sloping surface. The outer trays are arranged to receive material falling from an inner tray thereabove and to deliver material to the ridge of an inner tray therebelow.

Abstract: A method for thermal treatment of horizontal wire rings with convective heat transfer by means of circulated furnace gases, characterized in that said wire rings, particularly for thermal treatment above temperatures of 650.degree. C. are acted upon in the resting state from two sides, from the top and the bottom, with a directed flow of furnace gases in order to generate a turbulent flow condition in the center of said ring. As a result of this method, it is proper to connect wire rings for uniform thermal treatment. An apparatus for carrying out the treatment is also disclosed.

Abstract: A furnace is described as having a heat treatment chamber which is provided with banks of radiant heaters to heat a load that is placed within the chamber for heat treatment. The radiant heating of the load is improved by the addition of convection heating which is carried out by a plurality of nozzles that are designed to direct jets or streams of heated gas against the load positioned in the chamber.

Abstract: An industrial furnace, particularly a single-chamber vacuum furnace, for heat treatment of metallic workpieces, with a heating chamber which is formed in a housing, which heating chamber is heatable via heating elements and is provided on the bottom and on the ceiling with a closable chamber opening for the passage of a quenching gas which can be circulated by means of a blower. A flap is swingably mounted at the chamber opening underneath a closing slide, which chamber opening is provided for the entrance of the gas. The flap controls the incoming flow of gas within the range of the free cross-section of the chamber opening.

Abstract: A continuous flow heating oven of the industrial type used for the heating of ingots, sheet material and the like, which may be of light metal or light metal alloy, includes a burner fired with a liquid or gaseous fuel disposed within a heating chamber. The material to be heated is placed within the oven with the convection air currents generated from the burners directed thereon, with the hot combustion gases produced by the flames. In addition, the exhaust gases are compressed and directed back onto the object to be heated interspersing with the convection air currents originally generated to increase the efficiency of heating the material.

Abstract: An apparatus for treating a workpiece at elevated temperatures and pressures comprising an elongate cylindrical pressure vessel. Within the pressure vessel a hearth sits upon a pedestal. Surrounding the pedestal and the workspace immediately thereabove is an insulated furnace enclosure. A cavity near the base of the pedestal defines an impeller chamber. An impeller is positioned in the chamber and has a downwardly extending drive shaft. The impeller circulates the pressurized atmosphere. A remotely actuated gate directs the circulating atmosphere to either circulate totally within the furnace enclosure or partially within the furnace enclosure and partially along the interior wall of the pressure vessel.

Abstract: An axial flow, reversible fan for use as a plug unit in a heat treating furnace comprises a shaft, an impeller having opposing faces mounted on an end of the shaft and comprising a tankhead and a plurality of flat blades disposed about and extending radially therefrom, a first set of fixed concavo-convex vanes disposed about and extending radially from the shaft adjacent a face of the impeller, a second set of fixed concavo-convex vanes disposed about and extending radially from the shaft adjacent the opposite face of the impeller, and a driving means for rotating the impeller which is attached to the shaft.

Abstract: The present invention entails a bulk tobacco barn having a generally enclosed drying area and a forced air heating system associated directly with the barn for generating a system of air and circulating the air through tobacco supported within the drying area of the barn. As a part of the forced air heating system, there is provided heating means that is thermostatically controlled to heat the system of air to maintain an appropriate temperature level within the drying area of the structure during the curing and drying process. Provided in conjunction with the bulk tobacco barn is an auxiliary heating system that comprises a stove or heater having a fire box for receiving and burning material such as wood or coal.

Abstract: A heating apparatus having doors mounted on the inlet and outlet of a furnace body to cover them and at least one additional door disposed in an intermediate portion of the furnace body to divide it into compartment furnace chambers forming a preheating chamber, a heating chamber and/or a warmth-keeping chamber, from the inlet side to the outlet side. A hot air circulating device is disposed in each of the compartment furnace chambers in a manner such that areas close to each door are much heated. When a material to be heated is charged from the preheating chamber, outer air is shut off from the heating chamber, and when the material to be heated is delivered into the heating chamber, outer air is shut off from the preheating chamber. When the material is shifted from the heating chamber to the warmth-keeping chamber or is discharged to the outside from the warmth-keeping chamber, outer air is shut off in the same manner as above.

Abstract: An improved atmosphere circulation system involving the use of aspirators for inducing turbulence of pressurized atmosphere within a vessel promotes temperature uniformity within the vessel and, for a given degree of temperature uniformity, reduces energy consumption.

Abstract: A method and apparatus for recirculation of atmosphere in a vacuum furnace which comprises a recirculation loop in which there is a low pressure line from the furnace chamber leading to a recirculation pump which pumps the recycled gas at a higher pressure to a high pressure line back into the furnace chamber. A means to analyze the furnace atmosphere is in communication with the high pressure line and signals its measurements of the atmosphere analysis to a valve on an enriching line. The enriching line passes enriched gas into either the high pressure line or the furnace chamber as the valve opens or closes. A means is provided to withdraw the gas from the furnace chamber in order to maintain the desired furnace chamber pressure as enriching gas is added.

Abstract: An oven for a chromatograph is shown in which intake and exhaust ports are both located on the opposite side of the fan from the columns, and in such manner that ambient air entering through the intake port merges with hot air from the oven before reaching the columns.