Abstract: A method for manufacturing a dental restoration for a patient, where the method includes: obtaining a 3D scan of at least a restoration site of the patient's mouth, where the manufactured dental restoration is adapted for fitting to the restoration site; obtaining a CAD design of the dental restoration; milling the restoration from a material, where the restoration is milled both on an inside surface configured for fitting to the shape of the restoration site of the patient's mouth and on an outside surface, where the milling is according to the obtained CAD design; transferring the milled restoration to a retention means providing a fixed known position of the restoration relative to a post-processing machinery, where the restoration is retained on the inside surface, such that the outside surface of the restoration is approachable/free/accessible; and performing post-processing of the outside surface of the restoration.

Abstract: An indoor installation type combustion apparatus includes an upper surface of the exterior case has formed therein: a cylindrical exhaust connection port which is in communication with an exhaust duct and which is connectable to an exhaust pipe; a first cylindrical air supply connection port which is connectable to an air supply pipe of double-pipe system containing therein the exhaust pipe and which encloses the exhaust connection port; and a second cylindrical air supply connection port which is connectable to an air supply pipe of twin-pipe system which is separate from, and independent of, the exhaust pipe, a low-cost apparatus is provided in which the air flowing in from whichever the first and the second air supply connection ports will be treated by one and the same supply-air filter. An air supply box which is in communication with both the first and the second air supply connection ports is disposed.

Abstract: The invention relates to a dental furnace, in particular a firing furnace or press furnace, for firing or pressing a dental restoration part which is receivable in the furnace, possibly after pre-heating in a pre-heating furnace, and which is placeable on a base, in particular centrally thereon, wherein the dental furnace comprises a firing chamber whose diameter is larger than, in particular at least twice as large as, the largest dental restoration part to be fired, and which comprises a control device and an operating unit at the or for the dental furnace (10), wherein by means of the operating unit (26) the size and/or the weight and/or the number of the dental restoration part(s) (18) to be fired or pressed is adjustable in units.

Abstract: A batch annealing furnace includes a coil support base on which an end face of a coil is mounted and that supports the coil with an axis of the coil being upright, an inner cover that covers an entire body of the coil mounted on the coil support base, and a cooling pipe that extends downward from the upper part of the inner cover to a cavity of the inner peripheral part of the coil mounted on the coil support base and cools the coil from the inner surface side by passing a coolant through the inside of the cooling pipe.

Abstract: The invention relates to a dental furnace wherein a firing chamber is heated up in a first heating-up period at a first heating-up rate of more than 501 K/min, in particular more than 1001 K/min, which heats the furnace to at least 10001 C, in particular to 1100-12501 C. The first heating-up period is followed by an intermediate heating period, which is at least five minutes long, in particular at least ten minutes long, the gradient or heating-up rate of which is adapted to the material to be sintered in the dental furnace (10), and wherein this is followed by an end heating-up period (44) during which heating up is effected at a heating-up rate of more than 301 K/min, in particular approximately 501 K/min, and wherein during this the furnace temperature is held for at least five minutes, in particular for at least 25 minutes, above the temperature toward the end of the first heating-up period, and wherein forced cooling of the furnace (10) is performed after this.

Abstract: A method of manufacturing a honeycomb structure including a honeycomb unit includes forming a honeycomb molded body having a plurality of cells extending from a first end face to a second end face of the honeycomb molded body along a longitudinal direction of the honeycomb molded body and separated by a plurality of cell walls, placing the honeycomb molded body in a degreasing apparatus so that the first end face faces downward and the second end face faces upward, feeding introduced gas into the degreasing apparatus, degreasing the honeycomb molded body at a temperature of approximately 200° C. to approximately 400° C., and firing the degreased honeycomb molded body at a temperature of approximately 500° C. to approximately 900° C. to obtain the honeycomb unit.

Abstract: A method is described for preheating annealing goods in a hood-type annealing installation, comprising two annealing bases (1, 2) which accommodate the annealing goods (3, 4) under a protective cover (7, 8), with the annealing goods (3) to be subjected to a heat treatment under a protective cover (8) being preheated with the help of a gaseous heat carrier which is guided in a cycle between two protective covers (7, 8) and absorbs heat from annealing goods (4) which are heat-treated in a protective cover (7) and emits it to the annealing goods (3) to be preheated in the other protective cover (8). In order to avoid contaminations of the heat-treated annealing goods (4) it is proposed that the heat carrier flow guided in a cycle flows around the two protective covers (7, 8) on the outside, whereas a protective gas is circulated within the protective covers (7, 8).

Abstract: There is provided a thermal processing apparatus in which the outer shell of a vacuum insulation layer-forming structure has an increased buckling strength. The thermal processing apparatus 1 includes a cylindrical reaction tube 3, a boat 5 for holding wafers W, a heater 2 provided around the reaction tube 3, and a vacuum insulation layer-forming structure 10 provided around the heater 2. The vacuum insulation layer-forming structure 10 includes an inner shell 11 and an outer shell 12 which forms a vacuum insulation layer 10a between the outer shell 12 and the inner shell 11. The outer shell 12 is comprised of a thin plate having an undulating cross-sectional shape formed by plastic forming.

Abstract: A manufacturing method for producing a ceramic member by firing a formed body with a firing furnace. The firing furnace is equipped with 1) a muffle formed in a manner so as to ensure a space for housing the formed body to be fired; 2) a heater or a heat generator serving as the heater, which is placed outside the muffle; and 3) a plurality of heat insulating layers made of carbon, fixed by stoppers made of carbon, and formed in a manner so as to enclose the heater or the heat generator. The method fires the formed body with the firing furnace to form the ceramic member, and heats the muffle and the space for housing the formed body with the heater or the heat generator.

Abstract: A continuous firing furnace of the present invention comprises: a muffle formed into a cylindrical shape so as to ensure a predetermined space; a plurality of heat generators placed at the peripheral direction from the muffle; and a heat insulating layer formed in a manner so as to enclose said muffle and said heat generators therein, said continuous firing furnace being configured such that a formed body to be fired, which is transported from an inlet side, passes through the inside of said muffle at a predetermined speed in an inert gas atmosphere and, then, is discharged from an outlet so that said formed body is fired, wherein said inert gas flows through: a space between said muffle and said heat insulating layer; and a space inside the muffle, in sequence.

Abstract: An kiln for dental restoration components is provided, and comprises an indicator having an image screen for displaying information. The image screen is provided with at least two, and in particular at least three, surface areas with which optically distinguishable features, including colors, types and structures, can be represented. The surface areas together essentially form a front and/or side view of at least one tooth.

Abstract: A support frame for metal coils, which are stacked on top of each other for a heat treatment by means of a hot, gaseous medium, especially in bell-type annealing furnaces, has devices on the support frame for guiding the flow of the medium through the coils. The support frame is a framework constructed of I-sections. The end surfaces of the coils are supported on the flanges of the framework I-sections. The webs of the framework I-sections are provided with holes, which serve for guiding the flow of medium.

Abstract: A novel batch-type kiln and a method of use thereof are provided. The kiln comprises a kiln body and a heating chamber disposed within the kiln body, which has a heater disposed therein. A table is disposed at the bottom of the heating chamber, the table having a peripheral portion and an upper surface for supporting an object to be treated. The peripheral portion of the table and a portion of the kiln body define a gap therebetween. This gap forms a gas-introducing path for introducing a gas into the heating chamber. The batch-type kiln is capable of preventing accumulation of a binder component in the gap between the table and the kiln wall.

Abstract: A coolable arched roof for a high-temperature melting furnace having a furnace interior. At least the following layers are present on that side of a layer of refractory bricks, which is remote from the furnace interior: a sealing layer, which is used to seal the furnace interior against the leakage or penetration of gas; an insulation layer having a thermally insulating action; and a cooling layer, which is designed to carry a cooling fluid. The arrangement of layers results in an increased gastightness and prevents premature aging of the refractory bricks.

Abstract: In a thermal treatment apparatus comprising a plurality of thermal treatment chambers in which an object to be treated is thermally treated while being transported, at least one pair of two adjacent thermal treatment chambers of which inside temperatures are different from each other are connected through a thermal insulating structural member, whereby thermal conduction between the chambers such as muffles is prevented to reduce a heat loss caused in the thermal treatment apparatus, and therefore, input thermal energy which is necessary to carry out a predetermined thermal treatment is significantly reduced without affecting quality and yield of the object.

Abstract: A processing system including a chamber defining an interior cavity having a processing tube assembly arranged within the interior cavity. A heating assembly moveable relative to the processing tube assembly from a first position where said processing tube assembly is disposed within the heating assembly and a second position where the processing tube assembly is exposed to an internal environment within the interior cavity of the chamber.

Abstract: A radiation furnace assembly for use in heating parts. The radiation furnace assembly includes a muffle having a top side, a bottom side, and a first side wall The muffle defines a chamber with a main heating portion and a first side heating portion. Disposed adjacent to the muffle are top and bottom heating elements. A first control device is used to adjust the temperature of at least one of the top and bottom heating elements thus controlling the temperature within the main heating portion of the chamber. A first side heating element is disposed adjacent to the first side wall of the muffle. A second control device is used to adjust the temperature of the first side heating element independently of the top and bottom heating elements to increase the temperature within the first side heating portion of the chamber relative to the main heating portion.

Abstract: An apparatus for evacuating liquid condensation from pipe systems which is particularly applicable to exhaust pipe systems in high efficiency furnaces. The apparatus forms a junction sleeve between two pipes and has drainage channels which prevent condensate liquid from flowing from one pipe into the other pipe. A thermoplastic rubber composition of the apparatus dampens noise and vibration in the pipe system. External grooves provide locating features for mounting clamps.

Abstract: A radiation furnace assembly for use in heating parts. The radiation furnace assembly includes a muffle having a top side, a bottom side, and a first side wall. The muffle defines a chamber with a main heating portion and a first side heating portion. Disposed adjacent to the muffle are top and bottom heating elements. A first control device is used to adjust the temperature of at least one of the top and bottom heating elements thus controlling the temperature within the main heating portion of the chamber. A first side heating element is disposed adjacent to the first side wall of the muffle. A second control device is used to adjust the temperature of the first side heating element independently of the top and bottom heating elements to increase the temperature within the first side heating portion of the chamber relative to the main heating portion.

Abstract: Organic gases and the like containing poisonous dioxin and so on which are evaporated from articles when they are subjected to a heat treatment such as degreasing, are led from a muffle where they are heated into radiant heating tubes located outside the muffle and loaded with a negative pressure, and they are discharged into the air on account of the negative pressure working in the heating tubes after they have been substantially completely pyrolyzed in the heating tubes.

Abstract: A device for the combustion of solid fuel in the form of granules, pellets, chips or other fragmented or finely divided form, comprising a rotary reactor drum (1), which forms the main combustion chamber (13) and has a rear end wall (65) and at the opposite end an outlet (3) for combustion gases to a boiler part for heat transfer to water-cooled surfaces, for example, or other heat-absorbing means, an inlet (55) for combustion air to the main combustion chamber (13), means (40) for feeding fuel through the rear end wall (65) of the reactor drum and means for rotating the reactor drum around its center axis (2). Inside the main combustion chamber (13), in its rear part, is an inner, smaller drum (60), which is coaxial with the reactor drum (1) and has a perforated jacket. At least the bulk of the fuel is disposed to be fed into the inner, smaller drum (60) and from this to the surrounding main combustion chamber (13).

Abstract: A heating device for burning fuel pellets (2) having a spherical combustion area (7), the surrounding wall of which is perforated (37), is disclosed. The combustion area (7) is surrounded concentrically by a wall(40) having perforations (36) and is spaced from the wall (10) of the combustion chamber. The space between the two walls (10 and 40) is utilized to hold the fuel pellets which are ignited by a heated medium directed from the outside towards both the walls (10 and 40).

Abstract: A novel batch-type kiln and a method of use thereof are provided. The kiln comprises a kiln body and a heating chamber disposed within the kiln body, which has a heater disposed therein. A table is disposed at the bottom of the heating chamber, the table having a peripheral portion and an upper surface for supporting an object to be treated. The peripheral portion of the table and a portion of the kiln body define a gap therebetween. This gap forms a gas-introducing path for introducing a gas into the heating chamber. The batch-type kiln is capable of preventing accumulation of a binder component in the gap between the table and the kiln wall.

Abstract: The furnace for firing ceramic materials has a working surface including a firing area and a storage area. A hood is provided which is moveable motorically relative to the working surface and positioned above the firing area to define the firing chamber. A robot arm for moving the ceramic material into and out of the firing area is provided.

Abstract: An annealing furnace inner cover cooperates with a furnace base to define a treatment chamber within which a charge of metal such as steel is housed for annealing, wherein the inner cover carries at least one interior cooling conduit through which cooling water from an exterior source is circulated to expedite the cooling of gas that is circulated within the treatment chamber during cooling portions of an annealing cycle. The water cooled inner cover is especially well suited for expediting the cooling of stacked coils of steel sheet from an annealing temperature, and preferably utilizes a helix of cooling coils that surround mid-height portions of the stack, wherein the cooling coils are protectively housed within an inwardly facing recess defined by an enlarged diameter mid-height portion of the inner cover both to prevent cooling coil damage due to impact during cover movement, and to ensure that gas circulation within the inner cover is not adversely restricted by the presence of the cooling coils.

Abstract: Apparatus (10) and a method for vitrifying hazardous waste includes a melting vessel (12) in which hazardous waste and any other necessary components for forming a glassy mixture upon heating are introduced for heating by a heater (38), and a metallic containment vessel (46) of the apparatus receives the melting vessel so as to receive and contain any material that exits the melting vessel upon failure. A voltage is applied across spaced electrical connections (72) of the melting vessel (46) to heat material within the melting vessel. Any failure of the melting vessel (12) is detected by a sensor (48). Different embodiments of the heater (38) provide current flow through molten material (18) being heated, induction heating, electric resistance heating, and using the metallic mixing vessel (12) as an electric resistance element. A stirrer (39) can be utilized to mix the material (18) during the heating.

Abstract: A kiln has a bottom part with a support for goods to be fired and a top part with a firing chamber. A bearing arrangement including at least one pivot joint pivotably connects the bottom part and the top part. The bearing arrangement includes a lift bearing cooperating with the at least one pivot joint.

Abstract: A base is provided with a gas outlet pipe and a gas inlet pipe. A bell jar is placed on top of the base with an O-ring interposed between them. Thin-film solar cells and a Se powder are placed in a recess formed in a lower heating jig, and the lower heating jig is positioned on the base. An upper heating jig is placed on top of the lower heating jig. The upper heating jig is vertically moved by a vertically actuating mechanism. The upper and lower heating jigs are heated with a heater so as to react Se with the thin-film solar cells, whereby a CuInSe.sub.2 alloy film is formed. In a method of manufacturing a thin-film solar cell, a molybuden layer and a copper layer are formed on a substrate by sputtering. A selenium-dispersed indium layer is formed on the copper layer in a solution, which includes indium ions and dispersed selenium colloid, by electrodeposition. The thus formed selenium-dispersed indium layer and the selenium are heated in a sealed container.

Abstract: A vertical heat treatment apparatus that includes a reaction tube for wafers to be loaded into from below and a heating unit surrounding the reaction vessel, or a single wafer heat treatment apparatus having a holder which provides a mount for wafers being loaded one by one into a reaction tube for heat treatment. The reaction tube has a structure of, e.g., two layers with a first layer of synthetic quartz glass made from a silicon compound, such as silicon tetrachloride, as a raw material. The first layer represents a surface that comes in contact with a heat treatment atmosphere. The second layer is of molten quartz glass made from quartz as a raw material and is external to the first layer. Synthetic quartz glass contains such traces of metals that scattered amounts of metals released into a heat treatment atmosphere due to exposure of the reaction tube to high temperatures is substantially zero.

Abstract: Apparatus (10) and a method for vitrifying hazardous waste includes a melting vessel (12) in which hazardous waste and any other necessary components for forming a glassy mixture upon heating are introduced for heating by a heater (38), and a metallic containment vessel (46) of the apparatus receives the melting vessel so as to receive and contain any material that exits the melting vessel upon failure. A voltage is applied across spaced electrical connections (72) of the melting vessel (46) to heat material within the melting vessel. Any failure of the melting vessel (12) is detected by a sensor (48). A stirrer (39) can be utilized to mix the material (18) during the heating. The containment vessel (46) is preferably hermetically sealed around the melting vessel (12) to contain gases as well as any melted material received from the failed melting vessel (12).

Abstract: Apparatus (10) and a method for vitrifying hazardous waste includes a melting vessel (12) in which a stirrer (38) mixes hazardous waste and any other necessary components for forming a glassy mixture upon heating while an electrical current is applied across the melting vessel and the stirrer to provide electrical current flow, and a metallic containment vessel (46) of the apparatus receives the melting vessel so as to receive and contain any material that exits the melting vessel upon failure. Any failure of the melting vessel (12) is detected by a sensor (48). The containment vessel (46) is preferably hermetically sealed around the melting vessel (12) to contain gases as well as any melted material received from the failed melting vessel (12). The sensing of the failure can be either by a pressure change in the hermetically sealed chamber (58) or by sensing of the presence of material received by the containment vessel (46) from the failed melting vessel (12) such as by an electrical circuit type detection.

Abstract: Apparatus (10) and a method for vitrifying hazardous waste includes a melting vessel (12) in which a stirrer (38) mixes hazardous waste and any other necessary components for forming a glassy mixture upon heating while an electrical current is applied across the melting vessel and the stirrer to provide electrical current flow, and a metallic containment vessel (46) of the apparatus receives the melting vessel so as to receive and contain any material that exits the melting vessel upon failure. Any failure of the melting vessel (12) is detected by a sensor (48). The containment vessel (46) is hermetically sealed around the melting vessel (12) to contain gases as well as any melted material received from the failed melting vessel (12). The sensing of the failure can be either by a pressure change in the hermetically sealed chamber (58) or by sensing of the presence of material received by the containment vessel (46) from the failed melting vessel (12) such as by an electrical circuit type detection.

Abstract: Provided is an apparatus for producing a silicon nitride sintering body made of a furnace including a heater source. The furnace includes a furnace core chamber defined by at least one partition inside the furnace to prevent an atmosphere containing more than about 30 ppm of carbon monoxide from contacting said silicon nitride sintered body. At least an inner surface of the partition is made of a carbon-free heat-proof material which prevents formation of carbon monoxide gas in an atmosphere in contact with the silicon nitride sintered body during sintering. The furnace also includes a gas supply pipe for supplying an N.sub.2 gas or an inactive gas including an N.sub.2 gas into the furnace core. Also provided is a sintering case made of a vessel defining a sintering atmosphere. The vessel has an opening for loading an object to be sintered into the vessel.

Abstract: A heat treating furnace has a hot zone enclosure with a substantially rectangular cross section. The floor of the hot zone enclosure is formed such that it is removable independently of the remainder of the hot zone enclosure. The heat treating furnace has a heating element with a novel support element that is readily mounted on and removed from the hot zone enclosure and which adjusts to accommodate a wide range of heating element thicknesses and insulation shield thicknesses. The electrically insulating components of the support element are formed to resist electrical shorting resulting from metallization and to resist cracking from thermally induced stress. The heat treating furnace further includes a cooling gas injection nozzle formed to reduce turbulence in the injected gas stream and to be readily attached to or removed from the hot zone enclosure.

Abstract: The invention relates to a device for soldering components on plates under the influence of a gas, having an at least two-piece housing, wherein a seal is provided between the housing elements. It is proposed to employ a liquid as the sealing means. It is achieved by means of this that the mechanical stresses occurring because of thermal stress can be absorbed immediately, because of which the formation of a leak is prevented in a simple manner.

Abstract: A heat treating device including a pressure detecting unit for outputting an output signal when a pressure in a heat processing furnace becomes a set value, an air release pipe having a first valve and a check valve, a differential pressure gauge shut off by a second valve in terms of pressure from the interior of the heat processing furnace, and an air feed pipe having a third valve. One ends of each of the air release pipe and the air feed pipe is connected respectively to the heat processing furnace and the other ends opened in air. In such arrangement, after processing gases are evacuated from the heat processing furnace, an inert gas is fed. Then when an internal pressure of the furnace becomes near an air pressure, the first valve is opened in response to the output signal of the pressure detecting unit to make the internal pressure of the heat processing furnace a little higher than the air pressure.

Abstract: An improved seal arrangement is disclosed for use in batch coil annealing furnaces. The furnace has extending from its base a pair of cylindrical upright supports having exposed membrane engaging seal edges and between which an underpressure chamber is formed. The inner cover which removably rests on the base, has an annular top plate extending radially outwardly from its sidewall adjacent the cover's bottom end. Extending vertically downwardly from the top plate are concentric inner and outer clamp mechanisms which clamp flat annular elastomer seal therebetween. An overpressure chamber is formed between the seal and the top plate and when the inner cover is seated on the base, an underpressure chamber is formed between the seal and the upright supports.

Abstract: A muffle furnace assembly for brazing aluminum heat exchanger workparts comprises a tubular muffle having a workpart conveyer extending therethrough. A pair of fans disposed inside the muffle circulate high temperature atmosphere through the workparts. The muffle is surrounded by an insulative outer shell spaced to form an interstitial cavity therebetween. High temperature combustion gasses are directed into the interstitial cavity and flow in a helical path about the muffle. Louvers are provided in the muffle, between the workparts and the fans, for regulating the amount of inert gas flow within the muffle. Inlet and exit vestibules usher workparts into and out of the furnace assembly to minimize oxygen contamination within the muffle.

Abstract: An improved convective heat transfer arrangement is disclosed achieving overall heat transfer efficiencies in the neighborhood of 30 Btu/(hr. ft.sup.2 .degree.F.). A heat transfer conduit including a heat transfer wall is axially divided into a plurality of axially extending heat transfer chambers by a plurality of transversely extending baffles. Each baffle is especially configured to have an axially extending recess formed therein through which extends an orifice opening. Heat transfer gas pumped through the conduit cascades through the heat transfer chambers forming and reforming nascent free standing jet streams through each baffle orifice which impinge the heat transfer wall to achieve very high heat transfer coefficients while efficiently utilizing the available heat in the heat transfer gas.

Abstract: A heat processing apparatus comprises a heating furnace, a process tube located in the heating furnace and having an open bottom, a manifold connected to the open bottom of the process tube, a sealing member sandwiched between the process tube and the manifold to air-tightly seal the process tube, a fixing member for fixing the process tube to the manifold, a heat transmitting member made of metal and sandwiched between the fixing member and the process tube to radiate heat at that area of the process tube, which is opposed to the fixing member, to the fixing member by heat conduction, and a heat exchange conduit arranged in the fixing member and having a passage through which heat exchanging medium flows to cool the fixing member by heat exchange.

Abstract: A hot-isostatic press adapted for rapid cooling of the hot zone after completed pressing and sintering of the material includes a pressure vessel, end closures, and a hot zone surrounded by thermal barriers. Between the thermal barriers and the pressure vessel with end closures there are colder spaces. At least one connection, located in the lower part of the thermal barrier and provided with a valve between the space next to the pressure vessel and the space below the bottom thermal barrier, is provided with an externally controllable valve. In the upper part of the thermal barrier there is an opening with a relatively large cross section and a valve is provided for the opening, which comprises a heat-insulated portion.

Abstract: A heating furnace for heating a porous preform made of fine particles of highly pure quartz glass for an optical fiber, which furnace comprises a cylindrical furnace body, a heater installed in said furnace body and a muffle tube installed inside said heater to separate a heating atmosphere from said heater, wherein said muffle tube is made of highly pure carbon and coated with a gas impermeable carbon, which furnace prevents contamination of the preform with impurities and has long life.

Abstract: A sintering furnace includes an upper housing having a gas permeable insulating enclosure therein, with heating elements within the enclosure, and a lower housing having a hearth against which the insulating enclosure rests. Sweep gas is introduced to the interior of the upper housing, outside of the insulating enclosure. The sweep gas flows through the porous enclosure, past the pieces being sintered to sweep organics away, and out of the enclosure through an organics sink post extending upwardly from the hearth. The sink post is hollow and has openings therein, and is in communication with an external trap and vacuum pump, so that the organic-laden sweep gas is drawn out of the furnace. The insulating enclosure includes a gas barrier having openings therethrough and insulation layers on either side, the openings being sized such that the flow of sweep gas prevents diffusion of organic vapor out of the enclosure into the upper housing.

Abstract: There is provided a heating furnace comprising a furnace body, a cylindrical zone heater in the furnace body, a muffle tube installed through the furnace body for thermally treating a porous preform made of high purity quartz glass by moving the preform vertically therethrough and a partition means in the portion of the muffle tube projecting above the furnace body to divide an interior space of the muffle tube into an upper space and a lower one.

Abstract: The apparatus herein comprises a kettle for calcining particulate material and a surrounding furnace having a porous wall to pass heat of combustion into the kettle at one side and to permit evacuation of the products of combustion from an opposite side, and a control system to cycle the combustion and the evacuation of products of combustion between the opposite sides so that the side being evacuated becomes a heat sink to return the heat so retained therein upon the combustion cycle whereby the furnace structure is kept to a desirable level of temperature while the material in the kettle is at a significant higher temperature.

Abstract: A gas seal for a bell-type annealing furnace is described. A ring supported by the furnace cover and a resilient pad supported by the base mate to form a gas seal when the cover is rested on the base. A cover-supported cooling jacket and a base-supported cooling jacket cooperate to enclose the seal when the cover is rested on the base. Load bearing structure is provided independent of the seal elements to avoid subjecting the seal elements to the weight of the furnace cover.

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 method and apparatus for vacuum purging bell type furnaces is provided. A vacuum shell unit is provided which is removably emplacible over the inner cover of the furnce and has a vacuum tight seal to the base. A vacuum is pulled both within the inner cover and within the vacuum shell to remove the ambient gas. Nitrogen is then introduced into the inner cover and within the vacuum shell. The vacuum shell is then removed and purging continues within the inner cover either with nitrogen or other desired atmosphere gas, and finally furnace is emplaced over the inner cover to heat treat the work in a conventional manner.

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: A method and apparatus for vacuum purging bell type furnaces is provided. A vacuum shell unit is provided which is removably emplacible over the inner cover of the furnace and has a vacuum tight seal to the base. A vacuum is pulled both within the inner cover and within the vacuum shell to remove the ambient gas. Nitrogen is then introduced into the inner cover and within the vacuum shell. The vacuum shell is then removed and purging continues within the inner cover either with nitrogen or other desired atmosphere gas, and finally furnace is emplaced over the inner cover to heat treat the work in a conventional manner.