Abstract: In a tunnel kiln or other through-type kiln having aligned successive preheating, firing and cooling zones, counter-current air flows are provided in the preheating and cooling zones while essentially isolating the firing zone from air exchange by circulating air between the preheating and cooling zones through external conduits bypassing the firing zone, thereby substantially reducing energy consumption and providing environmentally safe exhaust from the kiln without substantial expense for air filtration.

Abstract: A semiconductor wafer-processing apparatus has a plurality of support members provided respectively for the processing units of a processing apparatus, and designed for supporting wafer receptacles each containing semiconductor wafers, and receptacle-inserting/extracting mechanism for inserting a wafer receptacle from the support members into the processing units, and for extracting the wafer receptacle from the processing units back to the support members. Receptacle-transporting mechanism is provided, operated independently of the receptacle inserting/extracting mechanism, for transporting the wafer receptacle between each support member and a predetermined position.

Abstract: A bakery oven of the type employing a continuous conveyor therein for carrying goods to be baked through an oven enclosure includes an air distribution system adapted to direct heated air from near the top wall of the oven enclosure to the bottom and sides thereof. The air distribution means includes a fan mounted on the top wall of the oven which includes at least one fan blade located within the oven enclosure, a fan shaft secured to the fan blade and extending through the enclosure top. The fan shaft is mounted on the top of the oven for rotation and is driven by a separate motor also mounted on the top of the enclosure in spaced relation to the shaft. A drive belt is provided to transmit rotary power from the motor to the shaft. As a result, the shaft is fully exposed for air cooling and heat from the interior of the oven is not transmitted to the motor.

Abstract: The present invention provides an oven comprising an elongate chamber with an inlet orifice at one end and an outlet orifice at the other end, via which a filament can pass through the chamber. Primary nozzles for use in introducing hot gas into the chamber are arranged, together with a gas outlet port, adjacent to the said one end of the chamber. Preferably the outlet port is nearer to the said one end than the primary nozzles. Secondary nozzles also for introducing hot gas into the chamber are arranged adjacent to the other end of the chamber. In use, hot gas is fed under pressure into the chamber via the primary and secondary nozzles against the direction of filament travel. Whilst the hot gas is fed under high pressure through the primary nozzles, the hot gas is fed at a relatively low pressure but high volume through the secondary nozzles. In this way the filament is heated all along its length in the chamber.

Abstract: Two concentric and relatively displaceable cylinders mounted on the center axis of a vacuum furnace between its load chamber and its blower serve to control the gas flows in said furnace, where said gas flows are used to heat and cool the load portions.

Abstract: An oven employing a group of identical modular oven units, each unit divided into a main cavity with a first upper auxiliary chamber and a second lower auxiliary chamber. A barrier plate separating the upper chamber from the main cavity is gas pervious and serves as a filter to separate micron size particles and larger from entering the main chamber as the particles are carried by heated inert gas or air passing into the main cavity. The barrier plate separating the lower chamber from the main cavity is also gas pervious and serves as a sink to adsorb particles of sizes up to 100 microns. The group of modular ovens is partially surrounded by a heat transfer wall which allows heat to be rejected from the modular ovens and removed by a fluid coolant in contact with the wall.

Abstract: A charging device suitable for use in processing scrap comprising a charge box open at the top, a pusher, and a moveable plate supported for sliding movement from a position with the charge box open to a position to close the charge box; the charge box having a top, bottom, front and rear, the charge box for receiving scrap through the top thereof and being in communication at the front thereof with an apparatus for handling scrap; the scrap being pushed by the pusher for pushing the contents of the charge box into the apparatus for handling scrap, the pusher being moveable from a position at the rear of the charge box remote the apparatus for handling scrap to a position at the front of the charge box proximate the apparatus for handling scrap; the pusher being supported by a support frame fully enclosing the pusher, when the pusher is remote the scrap receiving process; the moveable plate having a shearing edge at its leading edge and for co-operative movement with the pusher, the moveable plate being movea

Abstract: The invention relates to a process suitable for thermally processing a material containing substances that can be degraded or altered by heat and substances that are heat resistant. The process involves predrying the material in a drying zone and a preheating zone and baking the material in a baking zone. The material is predried in the preheating zone in the presence of a minimal quantity of oxygen and in the baking zone in the presence of an increased quantity of oxygen. An indirect supply of hot gas is used for the baking step. A device for carrying out the process is also provided.

Abstract: Disclosed is a quartz tube for a furnace for processing semiconductor wafers. The furnace comprises:an elongated hollow body having opposed first and second ends and a longitudinal axis;an injector opening being formed in the first end, the injector opening including sidewalls which are spaced to slidably receive an elongated gas injector assembly through the opening; andan alignment jig received within the hollow body inwardly adjacent the first end and injector opening, the alignment jig including support means for engaging and aligning a gas injector with the injector opening to support a gas injector to emit gas substantially along the longitudinal tube body axis.

Abstract: An atmosphere furnace including a plurality of divided furnace units, work transfer devices connecting the adjacent divided furnace units and those for the divided furnace units at both ends of the furnace. Each transfer device includes a tubular connecting frame and a work transfer member housed therein and the work transfer member has a work housing space in it. The work transfer member is rotatable, receives at a first position the work from outside or from an adjacent divided furnace unit into its work housing space, and send it out of the furnace or pass it to the adjacent divided furnace unit at a second position. When the work transfer member is at a middle position between the first and the second positions, the work housing space thereof faces an inner surface of the connecting frame so as to be sealed against the both end openings of the frame.

Abstract: A gas-fired oven is disclosed wherein heated air is delivered to an oven's interior from a gas burner located outside the oven in a way to enhance the convection heating properties and capacity of the oven. This is accomplished by means of a conduit which receives air heated by the external gas burner and internally discharges this heated air into the return air path of a blower used to recirculate hot air within the oven. The internal discharge end of the conduit is located adjacent to the blower's return air path so that the conduit does not obstruct the recirculating air. The external gas burner may be either an atmospheric burner or a power burner. Its gas burner head is axially aligned with the conduit's exterior inlet end and spaced a short distance from this inlet. The spacing between the burner head and the conduit inlet controls the dilution air which is required to regulate the temperature of the hot air according to the oven's function such as heating food.

Abstract: A wafer handling apparatus has a common desk including a top surface having a front zone, a middle zone and a rear zone, the front zone being capable of receiving plural indexers functioning as a wafer sender and/or receiver, a couple of wafer processing units disposed adjacent lateral sides of the middle zone, a wafer baking oven disposed adjacent a middle of the rear zone, and a wafer handling mechanism disposed adjacent a middle of the front zone, the wafer processing units and the oven.

Abstract: A pyrolyzer for gas chromatography having a subsidiary heater and a main heater. The subsidiary heater is set below the pyrolysis temperature of the sample, e.g., at 300 degrees centigrade, to drive volatile components from the sample. The main heater is set at a pyrolysis temperature to pyrolize the sample, e.g., at 600 degrees centigrade. The sample is placed in the pyrolyzer in a sample vessel that can be positioned to be heated by main heater, the subsidiary heater and a position not heated by either the main heater or the subsidiary heater.

Abstract: The invention relates to a continuous furnace for the heat treatment of articles, more particularly ceramic pipes. The continuous furnace comprises an upper part which is stationary in the conveying direction, can more particularly be raised and lowered and comprises the furnace crown 11, 12, 13, and a lower portion which can move in the conveying direction and comprises at least the furnace bottom. The lower portion is made up of a plurality of carriages 4 which are disposed close one after the other and each bear on an underframe 9 a portion of the furnace bottom 16 and at one end an end face partition 17 subdividing the furnace space into individual chambers. During the heat treatment the articles 24 to be treated remain on the carriage 4, thus eliminating the need for expensive devices for transferring the articles from one conveying means to another conveying means.

Abstract: A furnace used for high-temperature processing of semiconductor wafers employs a scavenger arrangement for removing effluent reactant gases which provides radial symmetry of gas flow. A scavenger chamber surrounds one end of a cylindrical furnace, and draws exhaust gases outward by a pressure differential. The scavenger chamber has a cylindrical quartz liner having a number of openings therein, the openings being circumferentially spaced about the end of the furnace so that gas flow is uniform and symmetrical. Preferably, these openings are in a plurality of groups, spaced from one another.

Abstract: A material heating oven for sterilizing items for use in a sterile environment or the like comprising a hot air supply device having a filter, a cool air supply device having a filter, an oven cavity separate from the hot air supply and cool air supply devices, and a dampering system for selectively drawing air from the hot air supply and cool air supply devices to regulate the temperature of the oven cavity. Both the hot air supply and cool air supply devices include independent air recirculation loops for maintaining substantially constant temperature airstreams from which selected quantities of air are exchanged with the oven cavity. The nearly constant temperature airstreams prevent the filters in the devices from being thermally stressed which may cause them to shed particles to the clean environment. An electrically controlled temperature control system is used to regulate the temperature of the airstream flowing through the hot air supply and cool air supply devices.

Abstract: A movable cantilevered purge system providing for a wafer load position, a wafer purge position, and a wafer process position. The movable cantilevered purge system includes an elephant carrier vehicle for movement of a movable quartz elephant tube. The movable quartz elephant tube includes a purge injector and a return exhaust tube. A cantilevered paddle clamping vehicle moves behind the movable quartz elephant carrier vehicle and holds a silicon carbide or ceramic paddle. The elephant carrier vehicle includes a quartz sealing ring and a stainless steel sealing ring carried on pivotable adjusting blocks, and are supported by a plurality of cylindrical tubes. The quartz sealing ring concentrically positions about the process tube of the furnace and a metal ring positions about a scavenger face. The return exhaust tube connects back into the scavenger area of the furnace.

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: A radiant wall drying oven that includes a first wall and a second wall situated in spaced apart relation to define an air conducting passageway. Heated air is supplied to contact the first wall, and a selected amount of heated air is allowed to pass through inlets into the air conducting passageway. Sliding dampers positioned at a predetermined site relative to the second wall control the amount of heated air contacting a portion of the second wall, and consequently regulate the amount of radiant heat emitted by that portion of the second wall.

Abstract: A thermoforming oven for the convection heating of a continuous web of a thermoplastic foam or film material which is being advanced through the oven towards a thermoformer. Moreover, there is disclosed to a method for the improved and more uniform convective heating of a thermoplastic foam or film material which is advanced through a thermoforming oven. A countercurrent flow of a gaseous heating medium is regulated and directed so as to impart the greatest degree of uniformity of temperature thereto during heating and blow-up to the thermoplastic material being advanced in an intermittent manner through the convective oven.

Abstract: A forced jet convection oven is utilized to practice a vacuum bagging process for the production of thermoplastic composite laminates containing reinforcing fiber. The oven comprises a support suitable for supporting a panel wherein said support means is positioned in the oven with the upper surface of the support means being spaced apart from the oven ceiling to define a panel-receiving chamber between the upper surface of the support means and the oven ceiling, a first manifold means having a first multiplicity of outlets directed toward the upper surface of the support means wherein said first manifold means is positioned between the upper surface of the support means and the oven ceiling; and a second manifold means having a second multiplicity of outlets directed toward the upper surface of the support means wherein said second manifold means is positioned between the upper surface of the support means and the oven floor.

Abstract: According to this invention, a boat carried by an elevator is put on a boat supporting unit installed at a boat delivery position and capable of moving up and down and then, the boat is delivered from the boat supporting unit to transfer means for a heat-treating furnace. Therefore, boats can be transferred by the common elevator to the boat delivery positions at heat-treating furnace arranged in multiple stages. Even when heat-treating furnaces of different types are installed in multiple stages, boats can be transferred to those furnaces by using the common elevator. As a result, when boats to be sent to different types of furnaces arrive at the work position, for example, boats can be delivered to the furnaces with extremely high efficiency and by simple devices.

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: The invention proposes a process and equipment for the thermal treatment of semiconductor materials which contains an isothermal, all-round heated process tube in a so-called "closed-tube" process using a compact construction of the furnace, whereby a defined process gas atmosphere is present in the process chamber from the very start of the process and a reverse diffusion is prevented. A double-tube system is used here with an adjustable interspace rinsing, i.e. the use of the so-called "rapid cassette" in cold blowing. Applications for the invention are in particular the oxidation, diffusion, deposition and tempering of semiconductor discs.

Abstract: An ingot pusher furnace of the vertical air flow type includes adjustable side baffles hingedly connected to lower ends of respective vertical side baffles to prevent the "short circuiting" of heated gases around the ends of an ingot to be heated. The adjustable side baffles are movable from a vertical position to an angled position so that its upper ends are in closely spaced proximity with the outer faces on the end portions of the shorter length ingot so as to produce a more uniform and faster heat transfer along the entire length thereof.

Abstract: A soldering apparatus of the reflow type contains a preheating chamber and a reflow chamber which are provided with a plurality of heaters for heating printed circuit boards with chips temporarily mounted thereon with solder pastes during conveyance by a conveyor. The heaters are provided with a screening member and/or a partition member so as to prevent direct radiation of radiant heat from the heaters into the chambers and onto the printed circuit boards and to provide a uniform air flow to be blown uniformly onto the printed circuit boards. The heaters are arranged so as to heat them in such a manner as to increase temperatures in the direction from an inlet to an outlet so as to become higher with a predetermined temperature differential from the previous heater, thus removing bubbles generated upon fusion of the solder pastes and minimizing heat shock to the chips as they are heated.

Abstract: A two-stage gas distribution nozzle for a muffle furnace includes an inner pipe with spaced apertures for feeding gas at spaced intervals to an outer pipe enclosing the inner pipe. The outer pipe includes spaced apertures facing in a direction such that the jets of gas from the inner pipe impinge on a wall of the outer pipe opposite the outer pipe apertures. The gas in the outer pipe is at lower pressure than the gas in the inner pipe and is more uniformly distributed along the length of the outer pipe to provide more uniform flow to the ambient atmosphere in the muffle.

Abstract: This disclosure is directed to a method for controlling the preheating zone of a tunnel kiln which includes firing and cooling zones. The method comprises forcedly blowing air from the entire ceiling portion of the preheating zone in the downward direction to diffuse hot combustion gas present in the upper portion and to reducing a difference in temperature between the upper and lower portions of the preheating zone. Air may be blown into the preheating zone at a flow rate determined from the quantity of the combustion gas within the preheating zone.

Abstract: A controlled diffusion environment capsule system (10) is used with a conventional tubular high temperature furnace (12) as employed in semiconductor manufacturing. The system (10) includes a cantilever boat loading apparatus (14) and a quartz diffusion capsule (16). Wafer carriers (20) support semiconductor wafers (22) concentrically with capsule (16) in closely spaced relationship for processing in the furnace (12). The diffusion capsule (16) is supported on a pair of quartz rods (24). A quartz injector tube (28) extends the length of the diffusion capsule (16). The injector tube (28) has three rows of high aspect-ratio apertures (30) extending along its length to disperse nitrogen or other inert gas uniformly across the surfaces (32) of the wafers (22).

Abstract: A heat treatment furnace for treating metal workpieces has a substantially cylindrical housing. The housing surounds a heating chamber having cooling gas inlets and outlets connected to a cooling gas circulation system for circulating the gas. A plurality of nozzles forming the gas inlets are mounted on the housing on two diametrically opposite sides thereof. The two sets of nozzles simultaneously direct cooling gases towards an impact zone within the heating chamber such that cooling gases meet in the impact zone. The workpieces are also supported in the impact zone of the heating chamber. A plurality of vents forming the gas outlets are placed around the periphery of the impact zone and conduct the cooling gas out of the heating chamber and into a heat exchanger.

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: The invention relates to a process and a continuous furnace for the thermal treatment of substantially flat bodies of a ceramic material. Disposed in a continuous furnace having a roller table 5, between a heating zone 1 and a cooling zone 2, is a firing zone 3 which can be divided off by partitions 6, 7 from the heating zone 1 and the cooling zone 2, and in which the bodies to be fired are very rapidly heated to firing temperature, being horizontally reciprocated to prevent deformations. During firing, the conveying of the bodies in the cooling zone 2 continues, while conveying in the heating zone 1 is interrupted, the movement of the bodies being completely stopped or the bodies being horizontally reciprocated. During the dividing-off of the firing zone 3 the gases heated in the cooling zone 2 are conducted via a bypass 12 to the heating zone 1, to participate in the heating of the bodies.

Abstract: Oven for charring plant matter, downdraft intermittent operation type, without external energy source. The invention relates essentially to the arrangement of the hearth located at the bottom of the oven, which provides the mechanical stability of the whole, the distribution of fresh air by means of a device permitting the circulation of air on the inside, as well as the precise control of its admission and airtight sealing at the end of the cycle; the collection of gases and pyroligneous liquors by means of an annular collector terminating in a single flue. The pyroligneous liquors are collected at the bottom of the flue. A condenser maybe installed to recover tars or to provide complete processing of the gases. Removal of the charcoal by gravity through a central opening, the cover of which contains the closable lighting aperture.

Abstract: Apparatus is provided for heating powder material charges to high temperatures at a fast rate, and for moving the charges through process operations, and for maintaining the temperatures of preheated charges and protecting the charges against contamination as they are moved through process operations. Such apparatus includes: a charge enclosing heated enclosure body having two or more separate sections; an internal wall in the enclosure body sections that has an internal cavity having a configuration shaped to hold a desired charge configuration; heating means for the internal cavity wall to heat it to desired temperature.Apparatus is also provided for heating metal, ceramic and similar material charges to high temperatures at a fast rate, and for moving the charges through heating and process operations, and for controlling the temperatures of preheated charges and protecting the charges against contamination as they are moved through process operations.

Abstract: An electrically heated kiln having a ventilation system in accordance with the present invention includes a hinged upper wall, a lower wall, and side walls forming a firing chamber. The kiln further includes an upper ventilation aperture formed in the upper wall and a lower ventilation aperture formed in the lower wall. A duct connects the lower aperture with the outside environment. An exhaust fan, coupled to the duct, draws incoming air into the kiln through the upper aperture, downwardly through the kiln, and outwardly through the lower aperture into the duct to be expelled outside. The downward movement of the air and kiln gases causes turbulence near the upper portion of the kiln to create a more uniform temperature within the kiln. The apertures are sized and the draw rate is selected so as to provide proper ventilation of the kiln. The draw rate is preferably between 8% and 45% of the kiln volume per minute when measured at room temperature through the lower aperture.

Abstract: A conveyance channel (76) connects an inlet valve (74) to a free outlet (82) whereby the conveyance channel (76) first passes through a sterilization zone (78) and then through a cooling zone (80). Within the cooling zone (80), the conveyance conduit contains resistor areas (94, 96). This makes it possible to reduce the conveyance pressure in the conveyance channel (76) against the outlet (82) to such an extent that packings sterilized in the conveyance channel (76) are able to exit the outlet (82) virtually pressureless.

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: Apparatus for the heat treatment of a length of continuously moving material in a plurality of treatment zones contains a fan to provide a stream of circulating air. The outer wall of the machine and fan housing is provided with an opening which can be closed by a closure device, through which the interior of the fan housing and the nozzle casing are accessible.

Abstract: The invention relates to a continuous material heating oven ideally suited for sterilizing and depyrogenating materials for introduction to a sterile environment. The oven includes a cool air supply means which is self-deprogenating eliminating the need for manual sterilization. A volumetric airflow control means is included with the cool air supply means for substantially linearly cooling materials to reduce breakage. Control means is provided by the system for maintaining the sterile environment at a greater positive pressure than its adjacent environments to protect the sterile environment from contamination.

Abstract: A process for treating workpieces in a normally closed treatment chamber. The process comprises providing a pressure within the chamber which is less than atmospheric and providing an unsaturated treatment vapor within the chamber. A workpiece is then moved into the chamber to be treated by the unsaturated vapor. The process is particularly suited for the vapor phase soldering of printed circuit boards. The unsaturated vapor in the chamber is heated to a temperature higher than the melting point of the solder used and the circuit boards with solder thereon are passed through the vapor in the chamber to reflow the solder.The invention is also directed toward an apparatus for carrying out the process.

Abstract: A process is provided for cooling fired products such as tiles in a kiln by repeating a cooling step to cool down said products, the cooling step comprising blowing a cooling gaseous fluid, e.g., cooling air, to the fired products in the kiln, alternately with a non-cooling step to moderate a sharp temperature gradient between the surfaces and the interior regions of the products, the non-cooling step comprising stopping or suppressing the blowing of cooling gaseous fluid between cooling steps. The process of the invention can achieve rapid cooling without giving rise to dunting due to thermal stresses and thus can increase the productivity of kilns. When the invention is applied to a tunnel kiln, the kiln can be considerably shortened.

Abstract: An oven is provided for baking a substrate having a printed circuit obtained by depositing on an insulating substrate, by silk screen printing, an insulating or resistive ink comprising an organic material which forms a temporary binder of this ink, which oven is provided with gas injection means for baking in the desired atmosphere, means for extracting the reducing gases and/or baking residues obtained by transformation of the organic materials under the effect of the temperature, and means for sweeping these reducing gases in the direction of the extraction means so as to accelerate removal thereof without creating any zone of stagnation or turbulent flow.

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 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: In the modular kiln, which is designed for the firing of ceramic tiles etc., one has a series of single treatment zones (16) arranged in a continuous succession and interconnected by a conveyor (6); heat exchange is brought about by radiation between special surfaces built into the various zones of the kiln, and the material being fired.

Abstract: An apparatus for baking treatment of semiconductor wafers comprises a furnace portion and a conveyor portion. The furnace portion has a baking chamber in which is installed a turntable on which baking cassettes are supported during baking treatment and a mechanism for circulating hot air through the baking chamber. The conveyor portion has a conveyor mechanism which moves cassettes for transporting wafers along a path from an entrance to an exit of the conveyor portion, a transferring mechanism which can transfer wafers from a cassette for transporting wafers to a baking cassette and vice versa, and a cassette insertion and removal mechanism for inserting and removing a baking cassette from the baking chamber of the furnace portion and mounting it on and removing it from the turntable.

Abstract: A continuous heat treating furnace is equipped with an automatic flow control system and contains a high-temperture treating zone internally provided with a plurality of burners, a pre-heating zone connectively disposed at one end of the high-temperature treating zone and a cooling zone connectively disposed at its other end, the pre-heating and cooling zones being partitioned into a plurality of compartments each provided on its ceiling portion with a convection fan.

Abstract: The invention resides in the temperature control of the oven of a gas chromatograph. A variable speed fan circulates air within the oven. Vents in the oven wall open automatically in response to pressure imbalances between the ambient atmosphere and the oven interior. Temperature is controlled by regulated exchanges of ambient and oven air produced by variations in fan speed.