Abstract: In a method of minimizing the temperature difference on a large area plate in a sintering step of manufacturing a solar cell and using a cover for making the heat equal, a cover with the hole pitch and the hole location being set in it is used in an analysis to quantitatively determine the cover shape for realizing the equal-heat heating, whereby the heat equalizing operation of the plate can be realized.

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 high temperature, low NO.sub.x industrial furnace uses coal-fired burners placed in an arcuate heat track conduit which heats an arcuately configured wall member extending through an opening in the heat track conduit. The heated portion of the wall member rotates out of the heat track conduit to indirectly heat a bundle or bank of heat exchange tubes while an unheated wall portion moves into the opening vacated by the heated wall portion. The regenerative heated wall member thus permits the heat exchange tube bundle to be heated to high temperature without exposure to the burner products of combustion. The coal-fired burners are operated substoichiometrically to produce combustibles and a free-standing, jet entrainment arrangement is utilized to achieve staged combustion to avoid NO.sub.x formation.

Abstract: A method and an apparatus for heat treating in a heat treating apparatus having a heating chamber to be introduced with predetermined gas, a heater disposed around the heating chamber, and jigs disposed in the heating chamber for supporting wafers of a plurality of substrates to be treated in parallel with each other, wherein in order to make the temperature distribution of the wafers of the substrates to be treated in the radial direction uniform in the heat treatment, the jigs are formed to determine the sizes and the shape thereof in predetermined ranges having a gradient according to the heat treating method having a predetermined shape determining procedure so that the jigs are formed in ring-shaped trays (i.e. support-ring) for holding at the peripheries the substrates to be treated and the thickness of the tray is constant or such that the outer peripheral side thereof is thicker than the inner peripheral side thereof.

Abstract: Apparatus for heating longitudinally extending portions of a blow molding preform in order to provide a non-symmetrical temperature distribution about a longitudinal axis of the preform. The non-symmetrical temperature distribution permits the preform to be blown to form a non-symmetrical article that has an essentially uniform wall thickness distribution. An auxiliary heating and transfer station is provided between a reheating station and a blowing station, the auxiliary heating and transfer station including two side-by-side pairs of heating elements that are adapted to heat sequentially, corresponding sides of each of a pair of side-by-side blow molding preforms carried by a pallet. The two zone auxiliary heating arrangement permits the desired temperature rise to be achieved consistently while retaining some process flexibility.

Abstract: A vertical heat treatment apparatus has a reaction furnace, gas-introducing mechanism, a gas-exhausting mechanism, and temperature-sensing means. The reaction furnace is made up of a reaction tube and a heating mechanism. The reaction tube contains a plurality of objects which are to be treated and which are arranged at predetermined intervals. The heating mechanism is arranged outside of the reaction tube. The gas-introducing means introduces a gas into the reaction tube, and the gas-exhausting mechanism exhausts the gas from the reaction tube. The temperature-sensing mechanism includes a guide pipe which passes through the side wall of the reaction tube and which extends along the inner wall of the reaction tube in the longitudinal direction of the reaction tube. One end of the guide pipe is closed and is located inside the reaction tube, while the other end thereof is open and is located outside of the reaction tube. A bendable temperature-measuring device is inserted in the guide pipe.

Abstract: Production apparatus for vapor-grown fine fibers, comprising a vertical furnace and a horizontal furnace intersecting each other in an L-shaped configuration. Raw material and catalyst and carrier gas are injected into the top of the vertical furnace to form fine fibers that fall freely through the vertical furnace and land and rest on a conveyor in the horizontal furnace for conveying the fibers through the second furnace while the fibers grow in size. Gas and fibers are discharged from an end of the horizontal furnace remote from the vertical furnace. The horizontal furnace has second injecting structure injecting material for fiber growth but no catalyst into said horizontal furnace.

Abstract: A vertical heat treatment apparatus includes a casing, a vertical heat treatment furnace provided in the casing, a substrate holding unit mounted in the casing for holding substrates to be heat-treated in the vertical heat treatment furnace, a loading/unloading unit having a wafer boat for supporting the substrates, the loading/unloading unit being adapted to put the substrates in and take the same out of the vertical heat treatment furnace, and a transportation robot for moving the substrates between the substrate holding unit and the wafer boat. The vertical heat treatment apparatus further includes a clean air supplying unit for supplying clean air sideways to the wafers supported by the wafer boat when the loading/unloading unit is at an unloading position, a and duct for introducing air from the outside of the apparatus. The clean air supplying unit is provided with an air filter disposed opposed to the wafer boat.

Abstract: An apparatus and method for processing a workpiece in an ambient-free, atmosphere of selected gas. A preparation vessel has an opening for entry of the workpiece and a diffuser oriented to emit across the vessel opening a laminar curtain flow of the selected gas which enters, purges the vessel and prevents the infiltration of air. The workpiece on its carrier is transported into the preparation vessel where air is purged out and replaced with selected gas. A processing vessel has a similar workpiece entry opening and diffuser. The preparation vessel and the processing openings are brought into coincidence, and the carrier is transported into the processing vessel for processing of the workpiece in the atmosphere of selected gas provided by the processing vessel diffuser.

Abstract: A control system for heat-treating parts in a furnace structure is provided. A plurality of processing chambers, each having at least one part position, are adapted to simultaneously process a plurality of parts each for a respective predetermined processing time. A memory device stores first records representing processing times associated with each of the parts within each processing chamber, second records representing a desired processing path associated with each part through at least one processing chamber, and third records representing the number and location of occupied part positions within each processing chamber. A computerized control center calculates desired processing times associated with at least one processing chamber for a new part to be processed in the processing chamber.

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 sufaces (32) of the wafers (22).

Abstract: An apparatus for flame treating an exterior surface of a plastic container such as a barrel includes a carriage mounted on a frame for rotatably supporting a plastic container, a first treatment station attached to the frame for flame treating a facing end of the container and a second treatment station attached to the frame for flame treating the sides of the container. The carriage is attached to a cable driven by a first actuator for moving the carriage from a starting position for loading the container onto the carriage past the first station to the second station and back to the starting position. The carriage, a burner at the second station and a roller for rotating the container at the second station are all adjustable for accommodating various diameter containers.

Abstract: Disclosed is a baffle apparatus for insertion into a semiconductor wafer processing furnace to diffuse processing gases that are injected into the furnace by an injector nozzle. The baffle apparatus comprises: a diffuser plate assembly having an upper end and a lower end, the diffuser plate assembly having at least one diffuser plate against which injected gases are to be forced; and the lower end of the diffuser plate assembly being sized and shaped to engage with and be supported by an elongated wafer paddle.

Abstract: A thermal treating apparatus includes a reaction tube having an opening end and storing an object to be treated, an annular manifold arranged at the opening end and having an inlet for supplying a gas to the reaction tube and an outlet for exhausting the gas from the reaction tube, and a cover arranged on the opening end of the manifold. The surfaces of the annular manifold and the cover exposed to the inside of the reaction tube are covered by a material which is not corroded by the gas supplied to the reaction tube.

Abstract: Mixing of spent reactant gases with ambient air inside a semiconductor wafer fabrication facility is avoided and consequently corrosion of a scavenger box in a wafer fabrication facility is avoided. Repeatability of reaction gas results on wafers in a process tube is improved by maintaining precisely constant pressure in the wafer processing tube, which is operated close to ambient atmospheric pressure. This is accomplished by positioning an exhaust tube downstream from the wafers in the processing tube at a location that results in a uniform, repeatable reaction gas flow pattern between the wafers. Pressures at or near that point are measured by a differential manometer referenced to ambient atmospheric pressure to produce a pressure-indicating signal. The pressure indicating signal is electronically compared with a preset constant signal representative of the desired constant pressure at the pressure measurement point to produce an error signal.

Abstract: Disclosed are an apparatus for and a method of recording an image in which a heat-developable light-sensitive material and an image-receiving material are superposed on each other and the superposed two materials are inserted between an outer periphery of a heating drum and an endless belt wound around a plurality of rollers and are wound around the outer periphery of the heating drum by pressing the two materials against the outer periphery of the heating drum by the endless belt, and the heating drum is rotated by being pressed by the endless belt, so as to heat develop the heat-developable light-sensitive material and allow an image formed by heat development to be transferred onto the image-receiving material.

Abstract: A tube furnace used for high-temperature processing of semiconductor wafers or the like employs a cone-like shape for the gas inlet or nozzle where the reactant or insert gas enters the furnace tube. This conical nozzle produces a gas flow of faster velocities, following the flow streamlines, and avoids or minimizes recirculating gas cells. The amount of gas used in purging a tube with this configuration is reduced, and the time needed for thorough purging is also reduced. Greater process control, and enhanced process reproducibility, are also possible because of the reduction in overlap of process steps permitted by the faster purging. This feature of faster purging can, in addition, reduce the infiltration of ambient air which occurs during any processing step.

Abstract: Nitrous oxide emissions are reduced in an industrial thermal process and system which operates a gas fired burner at substantially sub-stoichiometric conditions to produce products of combustion rich in combustibles and control flame temperatures at temperatures which do not exceed predetermined levels. Completion air at stoichiometric proportions is subsequently employed to burn the combustibles. Regenerative and recuperative means to cool gases after each partial combustion step are used to extract heat and use is in conventional heating processes. A novel regenerative heat exchange system is used to extract heat from the gases so that the gases never exceed a temperature whereat nitrous oxide formation tends to occur.

Abstract: A process for firing ceramic shaped bodies is disclosed, which comprises the step of making a heating temperature in a temperature range up to a decomposing temperature of a shaping aid contained in the ceramic shaped body smaller than that in a temperature range from the decomposing temperature to a firing temperature. A tunnel kiln is also disclosed, which comprises a preheating zone, a firing zone, a waste heat zone, combustion burners provided at the firing zone, an exhaust means provided at an inlet side of the preheating zone for evacuating combustion gases from the combustion burners outside the kiln, and another exhaust means provided at an outlet side of the preheating zone for evacuating the combustion gases outside the kiln.

Abstract: A plurality of semiconductor chips are sequentially mounted on a rotary table, heated on the rotary table for a predetermined time, and ejected from the rotary table. The semiconductor chips ejected from the rotary table are fed to a bonding apparatus. The semiconductor chips are heated while the rotary table is stationary and are held to the rotary table by a vacuum chuck. The position of a semiconductor chip is adjusted before the semiconductor chip is ejected from the rotary table.

Abstract: A method for bringing a plurality of steel slabs to rolling temperature uses a furnace having a controllable energy supply. To accommodate variation of slab temperature at entry, especially mixing of cold and hot slabs, at least one virtual slab corresponding to a group of the steel slabs is determined, and the energy supply is adjusted in dependence on the desired mean temperature at exit from the furnace of the virtual slab. Suitably the furnace has at least two zones each with an individually controllable energy supply, and virtual slabs are determined for the slabs in each zone. Then the energy supply in each zone is adjusted in dependence on the desired mean temperature at exit from the furnace of the virtual slab of that zone and preceding zones.

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: Disclosed is a heat treatment apparatus comprises a body having an opening section on the clear room side, a furance disposed in the body, a process tube arranged elevatably relative to the furnace, and a preventing plate arranged closably at the opening section for shutting off the opening section when it is closed, thereby it is possible to prevent dust from entering into the clean room by closing the opening section with the preventing plate.

Abstract: Printed circuit boards, assemblies and the like are heated uniformly from edge to edge or to a desired lateral temperature profile while being conveyed through a heating area. The conveying systems reliably conveys circuit boards and the like through the heating area without dropping them. A rail heater is provided to heat rails supporting conveyors having pins to hold circuit boards and the like. A control for the rail heaters controls the temperature of the rails so the circuit boards are positively supported on the conveyors and have a uniform temperature profile or desired temperature profile from edge to edge.

Abstract: Printed circuit boards, assemblies and the like are heated uniformly from edge to edge or to a desired lateral temperature profile while being conveyed through a heating area. The conveying systems reliably conveys circuit boards and the like through the heating area without dropping them. A rail heater is provided to heat rails supporting conveyors having pins to hold circuit boards and the like. A control for the rail heaters controls the temperature of the rails so the circuit boards are positively supported on the conveyors and have a uniform temperature profile or desired temperature profile from edge to edge.

Abstract: A tube furnace used for high-temperature processing of semiconductor wafers employs an annular manifold around the opening of the furnace tube where the wafer boats enter and exit, and this manifold or collar has a number of gas outlets to produce a radially-inwardly directed curtain of inert gas, such as nitrogen, to provide a physical barrier to prevent ambient gas from entering the furnace tube when the tubular cantilever is removed for loading and unloading operations. The manifold may be of unitary construction or may be constructed in two half-cylindrical parts, with separate gas inlets for each, so that the manifold may be removed to allow cleaning or replacement of the furnace tube. A symmetrical scavenger box surrounds this end of the furnace tube, outward of the annular manifold, so the inert gas introduced by the manifold and any ambient gas are scavenged in a radially symmetric manner.

Abstract: A heat-treating apparatus includes a furnace for heat-treating wafers, installed so as to set its longitudinal direction vertically and having an opening which is formed in its lower end so as to allow a boat having semiconductor wafers mounted thereon to be loaded, a heat-insulating cylinder on which the boat is placed and which is adapted to keep the boat hot, a lifting unit for lifting and loading the boat and the heat-insulating cylinder into the furnace, and for lowering and unloading them from the furnace, a moving unit for pivoting the heat-insulating cylinder and retracting the cylinder from below the boat, and a handler unit for supporting and vertically moving the boat. After the wafers are heat-treated, the boat is moved downward by the lifting unit. The heat-insulating cylinder is retracted from below the boat by the moving unit while the boat is supported by the handler unit. Subsequently, the boat is further lowered by the handler unit so as to completely remove the boat from the furnace.

Abstract: A rotating-drum heat treatment apparatus for carrying out cooling or heating of a material to a desired temperature. The apparatus includes two drums arranged in a casing adjacent to each other for continuously cooling or heating the material to be heat-treated, to thereby increase a time required for the heat treatment of the material.

Abstract: An especially adapted kiln car transfer apparatus includes a transfer carriage for supporting at least one kiln car. The transfer carriage itself is supported upon transverse tracks (i.e., relative to the longitudinal dimension of the tunnel kilns with which the transfer apparatus is associated) so as to be capable of movements between adjacent ends of a pair of tunnel kilns. A generally inverted U-shaped housing is carried by the transfer carriage and defines an interior space sized and configured to accept a kiln car. A reciprocally movable wall structure is disposed within the housing's interior space. The wall structure may thus move between the opposing open ends of the housing in response to the continual advancement of the kiln car onto the transfer carriage, and hence, into the interior space defined by the housing.

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: An improved practice for the vacuum brazing of aluminum alloy workpieces in a multi-chamber braze furnace is disclosed. When magnesium-containing aluminum alloys are brazed in a furnace having a braze chamber and adjacent exit chamber, there may be advantage in providing thermal barriers between a load of hot brazed workpieces and the furnace walls of the exit chamber.

Abstract: A system and method for loading and unloading articles, especially adapted for moving semiconductor wafers into and out of a diffusion chamber. An article support is cantilevered for moving the articles into the chamber without touching it. A separately controllable cantilvered enclosure is provided for movement over the supported wafers when necessary for protection during the loading and/or unloading procedure. An inert gas controllably flows into the enclosure to provide a controlled atmosphere for the wafers during the loading and/or unloading procedure.

Abstract: A method and apparatus for conveying carbon black pellets to avoid breaking up the pellets and inhibit caking on the conveying means which may be a screw type conveyor that is sufficiently heated to inhibit caking of the carbon black. The conveying means is centerless ground to maintain uniform distances of relatively moving parts and the contact surfaces are electroless plated to further inhibit caking of the carbon black on the conveying means.

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 process and apparatus is disclosed for removing volatile contaminants from scrap metal. The process is carried out in a furnace maintained at a relatively constant temperature having a first zone in which volatiles contained on the surface of the metal are vaporized and a second zone in which carbon contained on the surface of the metal is pyrolyzed. The furnace also has a vibrating conveyor for transporting metal therethrough at a specific speed. The process includes the step of vaporizing and fluidizing the volatiles to produce fumes containing unburned hydrocarbons without oxidizing the metal. The hydrocarbon fumes are then burned to produce hot gas which is recirculated to the furnace so as to contact new incoming scrap metal.

Abstract: An apparatus for loading semiconductor wafers into a cantilever diffusion tube includes a cantilever paddle supporting a boatload of wafers. The paddle is moved into alignment with the open end of the cantilever diffusion tube. The open end portion of cantilever diffusion tube is moved to surround the paddle and boat load of wafers. The paddle is lowered slightly, causing the boat load of wafers to be supported on an inside surface of the cantilever diffusion tube and providing clearance around the paddle. The cantilever tube is withdrawn from the paddle, which then is withdrawn from the path of the cantilever diffusion tube. The cantilever tube and the boatload of wafers is moved into the hot zone of the furnace. After a heat treating operation, the cantilever diffusion tube is withdrawn from the furnace, and the reverse operation is performed to unload the boatload of wafers.

Abstract: Bulk materials containing volatile constituents are calcined in a two-stage process comprising a first heating stage at de-volatilizing temperature but below calcining temperature during which the material is turned over and mixed to accelerate its bulk heating rate without substantially accelerating local heating rate. The first heating stage is followed by a second heating stage at calcining temperature. A rotary hearth furnace adapted for the above process is divided into outer and inner connecting annular heating zones and has rabble means for turning over and mixing the charge in the outer zone and rabble means for transporting the charge through both zones.

Abstract: A hybrid reheating of polyester preforms which are to be stretch blown into containers wherein the reheating coupled with the controlled quick initiation of the blow stretch operation after final reheating produces a container which may be filled with a hot fill without there being any disadvantageous shrinkage of the container. The reheating is by way of a specific combination of quartz oven reheating and radio frequency reheating together with specific equilibrations of the temperature cross sectionally of the preform body. Polyester preforms may be reheated to a cross sectional center temperature ranging from 225.degree. F. to 260.degree. F. and stretch blow molded without undesirable surface crystallization occuring while the ability of the container to be filled with a hot filled substantially without shrinkage is increased.

Abstract: An improved apparatus for annealing an ion-implanted semiconductor sample duces the deleterious side effects otherwise associated with the process. A semiconductor sample, fabricated, for example, from indium phosphide or gallium arsenide, is set upon the fingers of a carrier which is displaced to the interior of an elongate furnace having its internal temperature maintained at the proper annealing temperature. Next, the fingers are rotated and the sample is placed on a number of razor blade-like edges extending up from an internal rack. The carrier is withdrawn and the sample is quickly brought to the annealing temperature for the precise period of time usually no more than 20 seconds. After the exact annealing period, the carrier is reintroduced and the fingers are rotated to lift the sample from the rack and the sample is withdrawn.

Abstract: An apparatus controls the temperature of a multi-zone furnace based on a given temperature distribution pattern, which pattern is automatically switched zone by zone while considering inter-zone thermal interferences as the work being heat-treated is changed by using a memory storing a series of such patterns for different kinds of works.

Abstract: A radiantly heated, travelling hearth furnace having a supplementary feed means positioned intermediate the initial loading point and the final take-off point to increase the capacity of the furnace for treating objects fed thereto. When the objects are pellets of iron oxide and carbonaceous reductant the provision of supplementary feed means about half-way along the travel path of the hearth promotes uniformity of product by inhibition of reoxidation of reduced iron by exposure to a fossil-fuel-fired furnace atmosphere.

Abstract: A sheet of a cross-linkable and foamable polyolefin resin is thermally treated on an endless conveyor belt formed of a plain weave wire net. A plurality of parallel, spaced apart rolls are disposed in a direction perpendicular to the direction in which the conveyor belt runs for supporting engagement and rolling contact with the conveyor belt to maintain the flatness of the conveyor belt. The belt is supported to prevent lateral and vertical displacement.

Abstract: The method comprises passing preformed bodies to be calcined, containing pyrolyzable substances, through a furnace having, arranged in succession, a first heating zone, a second or combustion zone wherein volatile substance released by said bodies are subjected to combustion, a third or calcining zone, and a fourth or cooling zone. Separation means between the first and second zones, and between the third and fourth zones, prevent the flue gases from flowing between such zones.

Abstract: A temperature control system (50) for use in a furnace (10) for heating metal logs (13) as the logs (13) move through a furnace heating chamber (12) includes thermocouples (52a-52e) adapted to sense log temperatures by direct contact during intermittent time intervals when the logs (13) are stationary. Radiation sensors (64a-64 e) continuously sense radiant energy emitted from the logs (13) and a temperature compensation circuit (62) compares signals representative of log temperatures as measured by thermocouples (52a-52e) and the radition sensors (64a-64e). The difference between the signals is utilized during time intervals when the logs (13) are moving as a compensation factor for the continuous signals representative of log temperatures based on sensed radiation. The compensated signals and signals representative of desired set point temperatures are applied to log temperature controllers (80a-80e) to regulate the thermal energy applied to the logs (13).

Abstract: An apparatus for loading a furnace with semiconductor wafers is known, which has at least two heat treatment chambers (1A, 1B, 1C, 1D), each of them having an associated stationary loading unit (8) with a receptacle movable in the direction of the furnace axis via a feed apparatus and having a loading system (2A, 2B, 2C, 2D) for semiconductor wafers. In order to provide such an apparatus for automatically loading the furnace with semiconductors which facilitates loading and overcomes the disadvantages of the known apparatuses, the apparatus according to the invention has a common central loading station (9) for all the semiconductor loading systems (2), and these loading systems are removable from the loading unit (8).

Abstract: The invention relates to a process and to an installation for the heat treatment of cylindrical bodies, in particular pipes, of ceramic material. During the treatment, the pipes are dried, heated and sintered, and subsequently cooled, in successively arranged chambers.During transportation through the drying zone, the heating zone and the cooling zone, as well as in heat treatment during sintering, the objects are turned about their own axis independently of the transportation rate, so that they are not only evenly heated, but a possible deformation is also prevented. This type of transportation and heating with possible heat exchange between the individual zones makes possible a rapid heating-up without detriment to the cylindrical bodies, and thus a short design length of the installation. Above all, the sintering zone, which must consist of high-value, ceramic material due to the high temperatures, can be kept very small.

Abstract: The process of operating a reheating furnace for slabs involves the transport of slabs through the heating chamber of the furnace and contacting the slabs with a hot gaseous fluid which is supplied by one or more channels at a level below the path for the slabs. The fluid is thereby cooled and the cooled fluid is withdrawn to be readmitted into the channels subsequent to mixing with hot combustion products which are furnished by burners. The temperature of the fluid which is a mixture of cooled fluid and combustion products matches or approximates the optimum temperature for rolling of the slabs. That portion of the heating chamber which is adjacent to its inlet constitutes a magazine for temporary storage of slabs and contains ways for a charging machine which delivers slabs into the range of a walking-beam conveyor in the heating chamber.

Abstract: A method of heat treating metallic workpieces using a continuous-heating, sher-type, or gravity-discharge furnace having at least two treatment chambers through which the workpieces successively pass. The chambers, which are provided with doors, serve to respectively heat treat a plurality of workpieces charges, with individual ones of the charges being cyclically received by the respective chambers, being conveyed through the latter while heat treatment is undertaken, and subsequently being released by the chambers. Charges requiring different treatment and/or duration, especially different case-hardening depths during carburization in a two-stage process, can be simultaneously treated while fully utilizing the capacity of the furnace by irregularly conveying the charges in at least one of the treatment chambers in such a way that the charges are released by the chamber or chambers after varying retention times.

Abstract: An apparatus for soaking steel pieces including cold steel pieces and hot steel pieces. The apparatus is of the type which includes: a soaking furnace for subjecting the steel pieces to a soaking treatment; a preheating chamber for preheating the cold steel pieces before the cold steel pieces are introduced into the soaking furnace, the preheating chamber being connected to the soaking furnace for receiving waste heat from the soaking furnace for the preheating treatment and having an outlet portion for discharging the cold steel pieces; and a mechanism for introducing the steel pieces into the soaking furnace and for advancing the steel pieces through the soaking furnace.

Abstract: A method of controlling the rolling efficiency in a continuous hot rolling process. A rolling schedule and a conveying schedule are determined on a mill line for the slabs arranged in succession based on an aimed extraction temperature of the slabs from a heating furnace and a predetermined temperature at the exit of a finish mill. A minimum extraction pitch is calculated for the slabs from the heating furnace under restriction of the side of the mill line, and a different minimum extraction pitch is calculated for slabs from the heating furnace under restriction of the side of the heating furnace based on slab temperature charged to the heating furnace and the aimed extraction temperature. An optimum extraction pitch is determined for slabs from the heating furnace by comparing both of the minimum extraction pitches. With such a method, the continuous hot rolling operation is carried out under an optimum condition.