Abstract: Disclosed is a process of stabilizing spent filter material that comprises mixing the filter media with a city media to produce a composition having a moisture content that is sufficiently low to retard microbial growth. The composition comprises spent filter media and a dry material, and preferably comprises diatomaceous earth. Soil is treated by adding the composition as a top dressing, soil amendment, or the like.

Abstract: Automated apparatus for preparing pizza, and method of operating same. A customer selects a type of pizza, such as toppings or crust style. The apparatus slices and defrosts dough, applies cheese, slices and applies toppings, and cooks the pizza to order. The cooked pizza is packaged for delivery to the customer and may include a separate cutting apparatus. Proper temperature of hot and cold sections is maintained while ingredients are stored and as the pizza is cooked. The process is monitored and controlled by one or more processors.

Abstract: Disclosed is a process of stabilizing spent filter material that comprises mixing the filter media with a dry media to produce a composition having a moisture content that is sufficiently low to retard microbial growth. The composition comprises spent filter media and a dry material, and preferably comprises diatomaceous earth. Soil is treated by adding the composition as a top dressing, soil amendment, or the like.

Abstract: A method and a device for controlling a process for burning lime containing mixture (CaCO3) and converting it to calcinated lime (CaO) in a rotary kiln, the rotary kiln having an elongated cavity surrounded by a wall and a burner arranged to heat the cavity. The method includes collecting measurement data of the temperature in the wall at a plurality of measuring points along the longitudinal axis of the cavity, predicting the actual temperature gradient along the longitudinal axis of the cavity based at least on the measurement data of the temperature in the wall, and by means of a thermal model describing the temperature along the cavity of the kiln, determining a desired temperature gradient along the cavity based on the predicted temperature gradient along the cavity and a predetermined control strategy controlling the temperature in the kiln.

Abstract: Provided is a rotary hearth furnace which can stir exhaust gas within a furnace, to efficiently burn flammable gas within the exhaust gas and to efficiently heat an object to be heated, and which can contribute to reduction of specific energy consumption and improvement of productivity. A rotary hearth furnace (1) has therein a series of zone spaces (3) which are divided by vertical walls (2) hanging from a ceiling (1c). Among the zone spaces (3), the zone space to which an exhaust gas duct (4) is attached is constructed as an exhaust zone (3a). An oxygen-containing gas supply unit (5) is provided in the vicinity of the lower edge of the vertical wall (2) which divides the exhaust zone (3a) from the other zone spaces (3). Further, the exhaust gas duct (4) is disposed on the outer periphery side or the inner periphery side from the center of the width of the zone space (3).

Abstract: A rotary hearth furnace for treating metal oxide materials comprises a hearth mounted for rotary movement within an enclosure. One or more fuel burners are positioned above the hearth. The burners are operably fired to heat the furnace so that heat radiates toward the hearth. One or more oxygen nozzles are positioned between the hearth and the burners in a manner that avoids substantial contact between the oxygen and the briquettes, thereby creating a quiescent zone immediately above the briquettes, with the quiescent zone being sufficient to minimize reoxidation of the reduced briquettes, and minimize entrainment of particulate matter from the briquettes.

Abstract: A Rotary thermal processor for particulate materials has a rotating drum and a rotating hollow auger. A stationary cylindrical oven with stationary coils surrounds the rotating drum. Hot gas heats a first part of the oven, coil and drum. A rotating hollow auger is heated with hot fluid from the coils. Oven exhaust sweeps evaporated and volatized components of the treated materials to separators and a thermal oxidizer. Cleaned gas from the thermal oxidizer heats a second part of the oven coil and drum and exits a stack. The rotating drum and auger lifts and turns the treated material as it is advanced by the auger.

Abstract: To provide a rotary hearth furnace which has a simple furnace structure in which the furnace is not damaged even if the furnace is operated for a long term while presenting general equations capable of adequately determining a thermal expansion margin in the rotary hearth furnace.

Abstract: PROBLEM TO BE SOLVED: To provide a rotary hearth furnace which has a simple furnace structure in which the furnace is not damaged even if the furnace is operated for a long term while presenting general equations capable of adequately determining a thermal expansion margin in the rotary hearth furnace.

Abstract: A rotary hearth furnace for use in the iron and steel industry comprises a furnace (12, 112) with plan in the shape of an annulus, closed at the bottom by a rotary hearth (14, 114), lined at the top with refractory material (15, 115), and a base (28, 128; 30, 130) of the furnace (12, 112). Said hearth (14,114) comprises a plurality of sectors of an annulus (17, 117; 17?, 117?), all the same as one another and connected to form an annulus, complementary to that of the internal plan of the furnace (12, 112), which rotate around the central axis of the annulus, by means of two concentric sets of wheels (26, 126) arranged according to two circumferences, set at equal instances, with supports (25,125), fixed to the base (28) or below the hearth (114), complementary to two circular rails (20, 120), fixed respectively below the hearth (14) or the base (128). According to the invention, both said sets of wheels (26, 126) and said two rails (20, 120) are positioned in such a way as to have an equal load distribution.

Abstract: A method for discharging a reduced product produced on a movable hearth of a movable-hearth furnace uses a discharging device. The discharging device includes a removal unit for removing the reduced product from the movable hearth, a separation unit for separating the reduced product from a solid reductant, a leaving-returning unit for either leaving substances other than the reduced product on a solid reductant layer or returning the substances onto the solid reductant layer, and a discharge unit for discharging the reduced product to the outside of the movable-hearth furnace.

Abstract: An annular rail 6 is fixed on the lower surface of a moving hearth 2, and the rail 6 is supported from below by support rollers 7 provided with elevating devices 8. The moving hearth 2 is continuously or intermittently moved downward by the elevating devices 8 depending on the thickness of a metal oxide layer formed by the deposition of powder of metal oxide agglomerates mixed into the furnace together with the metal oxide agglomerates so that a gap is provided between the surface of the metal oxide layer and the edge of the blade of a discharge screw 4 during operation.

Abstract: An arrangement for transporting metallic work pieces includes a heat-insulated transport chamber, means for loading and unloading the work pieces, and transporting gear. To enable the flexible and efficient transport of the work pieces among a number of treatment chambers in an arrangement of this type during a heat treatment process, the transport chamber is designed to be vacuum-tight, such that it can be evacuated of air to create a vacuum that will protect the work pieces from environmental influences. In addition, a system for heat treating metallic work pieces, comprising at least two treatment chambers in which the work pieces can be heat treated, is characterized in that an arrangement of this type can be coupled to the treatment chambervia a transfer canal that can be evacuated.

Abstract: The invention relates to an apparatus for cleaning and/or decontaminating polyester, in particular polyethylene terephthalate (PET). The apparatus has an at least partially heated rotary tubular furnace (1) to be fed with a mixture of polyester and an alkaline material and is for carrying out a saponification reaction in the mixture. The invention is distinguished in that within the rotary tubular furnace (1) a weir (22) is disposed which at least partly closes the interior (5) of the rotary tubular furnace (1).

Abstract: In a rotary hearth furnace for producing reduced metal through heating and reducing carbon containing materials composed of at least metal oxide-containing material and carbon-containing reduction material, a hearth structure is provided by which a refractory in a hearth lateral end is not damaged and carbon containing materials do not fall down to a water sealing section of the rotary hearth furnace. The upper part of a hearth lateral end 1a is covered with the lower end 2a of a side wall 2 of a hood covering the whole hearth, and a cooling means 3 is installed in the side wall lower end 2a.

Abstract: The invention provides a method and apparatus for charging a raw material and a carbonaceous material, in which a reduced product generated on a hearth can be quickly melted for reliable separation into a metal and slag, and the metal and the slag can be easily discharged out of a furnace as individual small agglomerates. With the charging method and apparatus, when charging the raw material and the carbonaceous material onto the moving hearth of the moving hearth furnace, the carbonaceous material is first charged onto the moving hearth to form a carbonaceous material layer thereon. The raw material or a mixture of the raw material and a carbonaceous material is then charged onto the carbonaceous material layer to form a raw material layer thereon. A projection is then pressed against the raw material layer from above, thereby forming a plurality of recesses in the surface of the carbonaceous material layer.

Abstract: To provide an operating method of a rotary hearth furnace for producing reduced iron in which a stuck substance stuck on the hearth surface is removed from the hearth surface to thereby prevent or reduce the wear of the knife edge of a screw of a discharge device, enabling continuous operation for a long period and capable of achieving high availability factor. The hearth surface is quenched by spraying or the like to generate cracks in the stuck substance on the hearth, and the stuck substance is scraped to thereby remove it from the hearth.

Abstract: In a rotary hearth furnace for producing reduced metal through heating and reducing carbon containing materials composed of at least metal oxide-containing material and carbon-containing reduction material, a hearth structure is provided by which a refractory in a hearth lateral end is not damaged and carbon containing materials do not fall down to a water sealing section of the rotary hearth furnace.

Abstract: An apparatus for producing reduced iron by agglomerating a mixed powder of an iron material and a reducing agent to form compacts like briquettes or pellets, and reducing the compacts in a high temperature atmosphere is disclosed. In the apparatus, a rotary hearth in an annular form is rotatably supported. Right and left furnace walls and a ceiling are provided to cover an area above the rotary hearth, thereby forming a space portion in a high temperature atmosphere. A compact supply portion, and a compact discharge portion are provided adjacently in the ceiling. Partitioning members are provided as partitions between the compact supply portion, the compact discharge portion, and the high temperature atmosphere space portion.

Abstract: A rotary hearth furnace for reducing a feed material is disclosed. The rotary hearth furnace includes a rotating hearth disposed in an enclosure and mounted for rotary movement. The enclosure includes an annular inner wall, an annular outer wall and a roof. The enclosure is sealed to the hearth and divided into a plurality of zones including at least a loading zone, a process zone and a discharge zone. The furnace further includes a plurality of burners positioned in at least the outer wall of the enclosure to provide a controlled temperature within the rotary hearth furnace and a flue positioned within the reduction zone of the furnace between the preheat zone and the discharge zone to exhaust combustion gases from the burners and gases resulting from the processing of the feed material. Said flue contains space for combustion and settling of the unburned particulates.

Abstract: An improved rotary hearth furnace having a cylindrical enclosure containing a radially moving belt for transporting pellets containing metal oxide and carbon is disclosed. One or more oxy-fuel burners preferably having a flat flame shape are positioned so as to provide a mixture of fuel and oxidant to the pellets countercurrent to the direction of the pellets. The oxy-fuel burners are operated so as to provide a pre-determined quantity of oxygen in addition to that necessary for combustion so that the additional oxygen oxidizes the carbon monoxide and hydrogen present in the hot combustion gases. Oxygen injectors may also be used to introduce additional oxygen into the furnace.

Abstract: The invention provides a method and apparatus for charging a raw material and a carbonaceous material, in which a reduced product generated on a hearth can be quickly melted for reliable separation into a metal and slag, and the metal and the slag can be easily discharged out of a furnace as individual small agglomerates. With the charging method and apparatus, when charging the raw material and the carbonaceous material onto the moving hearth of the moving hearth furnace, the carbonaceous material is first charged onto the moving hearth to form a carbonaceous material layer thereon. The raw material or a mixture of the raw material and a carbonaceous material is then charged onto the carbonaceous material layer to form a raw material layer thereon. A projection is then pressed against the raw material layer from above, thereby forming a plurality of recesses in the surface of the carbonaceous material layer.

Abstract: A process for manipulating workpieces, which are to be carburized, wherein the workpieces or workpiece magazines that are to be deposited on pallets are loaded in several rows, corresponding to a predefined number of rows of workpieces, into a rotating hearth furnace and, after carburization, are removed from the rotating hearth furnace and fed to a hardening press, exhibiting a predetermined number of press stations, and wherein on each pallet are deposited a number of workpieces or workpiece magazines, said number corresponding to the number of press stations. For better utilization of the capacity of the rotating hearth furnace and the hardening press, the pallets in the rotating hearth furnace are arranged in such a number of rows that the number of press stations is a divisor of the number of workpiece rows.

Abstract: An improved method and apparatus for loading, preheating and refining steel. The charging apparatus has a skirted charging section for introducing charge materials, a dynamic gas seal adjacent the charging section and a preheater, the preheater for preheating the charged materials, a connector adjacent the preheater and removably insertable into an electric arc furnace for feeding charged materials into a furnace bath for melting and refining metallic charge therein, and a vibrating conveyor which extends throughout the charging apparatus. The charging apparatus is positioned on rails to be movable by a drive engine between a charging position wherein the connector is fully inserted into the furnace, a retracted position where the connector is partially inserted into the furnace and a disconnected position where the connector is fully removed from the furnace.

Abstract: A rotary hearth furnace, in particular for the treatment of minerals or oxidized materials, includes a toroidal chamber wherein the bottom wall, i.e., the hearth, rotates as to the rest of the chamber the hearth includes a refractory material layer supported on a frame which includes the tracks cooperating with the wheels, placed on the ground, for the sliding and/or driving of said hearth. The frame includes several girts radial as to the hearth, angularly equidistant from each other, and at least two circular sliding girders, positioned next to the outer and inner peripheral edge of said hearth. The sliding girders are in contact with the hearth sliding and/or driving wheels through the suitable tracks, and the wheels are angularly equidistant from each other with the same angular pitch of the radial girts.

Abstract: Raw materials, including a metal oxide and a carbonaceous material, are supplied into a rotary hearth furnace. Then, the raw materials are heated and reduced by burners, which are arranged to cause a strong stirring action for an atmosphere around the raw materials, in an early reducing period that is defined as a period during which 70-80% of a total amount of a flammable gas generated from the raw materials is generated. In a latter period subsequent to the early reducing period, the raw materials are heated and reduced by burners arranged to cause a weak stirring action for an atmosphere around the raw materials, whereby a metal is manufactured. With the present invention, productivity can be improved and the fuel consumption per unit product can be reduced.

Abstract: The invention relates to a charging device for creating superimposed layers of fine-grained bulk material on a rotating hearth (2). For each layer of bulk material to be charged, said charging device comprises a discharge hopper (22) having an outflow slot (36) and a discharge roller (42) positioned ahead of each outflow slot (26). Said outflow slot (36) and discharge roller (42) extend essentially at a right angle to the direction of rotation of the rotating hearth and the discharge roller (42) has a drive (44), the rotational frequency of which can be controlled.

Abstract: An improved rotary hearth furnace having a cylindrical enclosure containing a radially moving belt for transporting pellets containing metal oxide and carbon is disclosed. One or more oxy-fuel burners preferably having a flat flame shape are positioned so as to provide a mixture of fuel and oxidant to the pellets countercurrent to the direction of the pellets. The oxy-fuel burners are operated so as to provide a pre-determined quantity of oxygen in addition to that necessary for combustion so that the additional oxygen oxidizes the carbon monoxide and hydrogen present in the hot combustion gases. Oxygen injectors may also be used to introduce additional oxygen into the furnace.

Abstract: The invention relates to a movable tunnel kiln for clay product manufacture and a production process system employing a tunnel kiln. Provided a kiln bottom of the tunnel kiln is fixed and takes a circular shape, the kiln body is circular and movable, road wheels moving on a circular railway are installed on both sides of the kiln body. A circular raw material aging pit concentric with kiln bottom is installed at the site inside the circular kiln bottom, and a complete brickmaking equipment is installed at the central part of the site. An operation mode of stationary bricks stack with movable kiln body is adopted in the invention, which changes the conventional operation of loading and unloading for the brick, and a plurality of cars with auxiliary facilities are cancelled, thereby greatly reduces the kiln construction cost.

Abstract: Furnace for the treatment of ore on a rotary hearth, including a toroidal chamber, a rotary hearth and drives for the rotary hearth, the hearth being arranged on a supporting frame fitted with guides means and motion-supports; the drives are at least partly connected to the said guides and/or to the motion-supports means.

Abstract: A feed stock composed of an iron ore and a solid reducing material is supplied in a movable hearth furnace provided with a unidirectionally movable hearth, stacked on the movable hearth and then subjected to a series of operations of preheating, reduction and discharge. To this end, a feed stock subsequently supplied in such furnace is preheated by utilizing a heat applied by the finished reduced ore and is stacked on the movable hearth.

Abstract: A fastener installing machine (10) comprising an oven (12) for heating fasteners, a carousel (14) for moving fasteners through the oven, a drive shaft (18) for rotating the carousel and means (32,38) for attaching the oven to the machine which means is disposed about the rotational axis of the drive shaft. A fastener installing machine (10) comprising an oven (12) for heating fasteners, a carousel (14) for carrying fasteners through the oven, an inlet to the oven for fasteners from a feeding mechanism, and an outlet from the oven to enable the heated fasteners to be attached to a substrate, wherein the inlet and outlet subtend an angle less than or approximately equal to 90.degree. with respect to the rotational axis of the carousel.

Abstract: In a rotary hearth furnace wherein objects including a mixture of a metal oxide, a reductant such as coal, and the like are fed onto the hearth, the fed objects are heated and reduced through the application of a flame of a burner provided on a ceiling portion or the upper portion of a side wall of the furnace, and the reduced objects are discharged from the furnace so as to be collected. The rotary hearth furnace has an air feeder for feeding air for secondary combustion at a position below the burner and in the vicinity of the hearth of the furnace for the purpose of burning a flammable gas generated from the objects. A flame of this secondary combustion accelerates the heating of the objects. Also, through a combined use of air for secondary combustion and excess air from the burner and an appropriate regulation of the ratio of therebetween, the objects are heated effectively.

Abstract: A process for feeding bulk material onto a belt of a rotary hearth furnace, which has hoods that cover the hearth belt in such a manner as to form a ring.The bulk material is deposited on a transport device at a layer thickness proportionately dependent on the distance to the rotary hearth center. The transport speed of the transport device is set at a certain value; the surface of the bulk material is smoothed; and then the bulk material is distributed at a constant layer height over the entire width of the hearth belt.

Abstract: A method pertaining to the baking of products (B) in a baking oven (1) in which the products are supported by at least one rotary oven trolley (17) comprises rotating the trolley through a number of revolutions in one direction (R1) during the baking process, and thereafter reversing the direction of rotation and continuing rotation of the trolley through several revolutions in the opposite direction (R2) before again reversing the direction of rotation of the trolley. The trolley (17) keeps the same axial position in both directions of rotation. An arrangement for carrying out the method includes a drive device (20-26) for alternating rotation of the oven trolley through an equal number of revolutions in both directions during the baking process.

Abstract: An apparatus for charging a feed material onto a rotating hearth of a rotary hearth furnace, the rotary hearth furnace including refractory lined inner and outer walls and having a refractory roof supported thereon, the apparatus comprising a table mounted above the rotating hearth and capable of receiving feed material from outside of the rotary hearth furnace, the table extends transversely across the rotating hearth and having a first end including a distribution member, a second end including a plurality of discharge slots, and an intermediate leveling plow; wherein feed material free falls over said distribution member and is distributed across the width of the table and then adjusted to a uniform depth such that as the rotating hearth passes under the stationary table a curtain of feed material is loaded onto the hearth.

Abstract: A rotary hearth furnace includes a base having a plurality of first plenums, an upper chamber having a plurality of second plenums and a hearth rotatable between the base and the upper chamber and having a plurality of third plenums. The hearth is moveable between the base and the upper chamber so that two or more of the third plenums are positionable to receive gas exhausted by one of the first plenums and to discharge the received gas into one of the second plenums.

Abstract: An oven comprises a housing with at least two zones, which are each provided with a device for setting a cooking state in the relevant zone, such as the temperature and relative humidity, as well as a conveyor belt, which runs through each of the zones and on which food products to be heated can be held, which conveyor belt has at least one path with a plurality of windings. These two zones are situated one above the other. Each zone has at least one ventilation device and also a heating device for circulating hot air through that zone and parallel to the boundary region between two zones.

Abstract: An oven for preparing food products comprises a housing, a conveyor belt which is movable through the housing and on which the food products can be arranged, which conveyor belt follows a helical path, heating elements and booster devices for generating a stream of hot air through the housing in connection with heating the food products arranged on the belt. In the housing there are guide elements for guiding the stream of hot air over the belt in such a way that the products are uniformly heated in the transverse direction of the belt.

Abstract: A rotary hearth furnace has a mixing rabble arrangement that includes a first rabble disposed upstream a flow of material on the hearth and a second rabble disposed downstream a flow of material on the hearth. The first and second rabbles are disposed at an acute angle with respect to a center of rotation of the hearth in a manner so that a plane defined by a plow of the first rabble intersects a plane defined by a plow of the second rabble adjacent the leading edge or training edge of the plow of the second rabble. The rabbles cooperate to produce a counter-rolling action in the material as the material is advanced into contact with the rabbles by movement of the hearth relative to the rabbles.

Abstract: A storage device 23 for storing a raw material to be calcined is provided at a position above a kiln cover 1, and the storage device 23 is connected to a preheating space 22 in such a manner as to be capable of dropwise supplying the raw material into the preheating space 22 by means of a raw-material supplying pipe 26. An airtight supplying mechanism 24 for dropwise supplying the raw material in a state in which the influx of air from the outside is prevented is provided between the storage device 23 and the raw-material supplying pipe 26.

Abstract: A device for heat-treating metallic workpieces in a vacuum has a revolving vacuum furnace with an inlet transfer lock for introducing a batch of workpieces into the revolving vacuum furnace and with an outlet transfer lock for removing the batch of workpieces from the revolving vacuum furnace. The revolving vacuum furnace has also an annular turntable for transporting the batch of workpieces from the inlet transfer lock to the outlet transfer lock. At least one carburization furnace, for carburization treatment of the batch of workpieces, is connected to the revolving vacuum furnace at least at a peripheral location of the revolving vacuum furnace between the inlet transfer lock and the outlet transfer lock in the direction of transportation of the batch of workpieces. The annular turntable transports the batch of workpieces to the at least one carburization furnace.

Abstract: A processing apparatus, conveyor and method for processing products or materials, such as food processing equipment or methods, is configured such that the conveyor travels in a generally helical path within a processing chamber to expose products on the conveyor to a gaseous processing media such as heated or cooled air. The conveyor includes gas flow compensation including a plurality of gas flow compensation members which partially block a portion of the surface of the conveyor, preferably toward the exterior of the conveyor in the helical path, to deflect or direct more of the gaseous food processing media away from the less densely distributed products or materials at the exterior of the conveyor caused when the conveyor follows the helical path. The processing media is thus preferably forced in the direction of the more densely distributed products toward the interior of conveyor to uniformly expose product on the conveyor to the processing media.

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 high temperature, low NO.sub.x industrial furnace 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 shrouded rabble includes a blade having an active face and a backface with a shroud extending from the backface along a lower edge of the blade. The rabble is suspended above a perforated hearth for urging charge materials on the hearth from one location to another in response to relative rotation between the hearth and the rabble. The action of the rabble on the charge materials causes breakdown of the charge materials and accumulation of fines on the perforated hearth. The shroud defines a shroud chamber behind the blade and screens charge materials from the shroud chamber to expose accumulated fines on the perforated hearth. The charge fines thus become fluidized in an upflowing heating gas and exit the shroud chamber through at least one opening in the shroud, facilitating the flow of heating gas through the perforated hearth and into the charge materials. The opening may simply comprise one end of the shroud being open, or it may include a plurality of holes in the shroud itself.

Abstract: A rotary oil seal gas purge system for a rotary carburizing furnace, having a rotatable hearth in a furnace chamber containing a high carbon-potential furnace atmosphere comprising an endothermic carrier gas enriched with a hydrocarbon gas, features gas purge ports located adjacent to the oil seal(s) of the hearth for injecting non-carbon-enriched endothermic gas to purge the high carbon-potential furnace atmosphere from the area adjacent the seal(s) and prevent carbon precipitation into the seal(s). Also disclosed is an oil seal management system for a rotary carburizing furnace including a settling tank for accepting seal oil from the furnace oil seal(s), a pump supply tank for receiving oil from the settling tank, a pump for pumping oil from the pump supply tank through a heat exchanger and to the furnace oil seal(s), and a centrifuge for cleaning seal oil coming from the heat exchanger before returning it to the pump supply tank.

Abstract: A high temperature gas fired heat transfer system ideally suited for melting metals is disclosed. The system generates a heated, reducing furnace atmosphere which prevents formation of metal oxides when the metal is melted. A unique arrangement is provided to draw a portion of the reducing atmosphere from the furnace and combust the drawn furnace atmosphere with high speeds jets of preheated combustion air which convectively impinge and heat the surface of an object to a super heat temperature. That surface is then moved into the furnace enclosure to indirectly heat by radiation and melt the metal at high throughput rates.

Abstract: The invention relates to a continuous furnace for shaping one of the faces of blanks of optical lenses to a desired profile by heat sagging of the blanks on suitably profiled jigs with the concomitant action of a vacuum.

Abstract: Expansion of granular or particulate material is effected by supplying such material, for instance slate chips, at a charging zone CZ of a kiln 10, to the upper surface of a rotating annular hearth 12 so as to lie thereon in a uniform layer up to about three chips in thickness. The hearth 12 is rotating in the direction of the arrow 96, and the chips face thereon just after a preheating zone PHZ. The chips are carried successively through a treatment zone TZ wherein they are subjected to heat from regenerative burner arrangements 68, 70 and 64, 66 beneath hood 44, to a discharge zone DZ whereat they are loosened by a reciprocating rake 80, 82 and are blown off the hearth 12 and into a receiver 88 by air jets from radially directed nozzles 78 supplied by way of a manifold 76. The kiln, and its manner of use, enables expansible material, such as slate chips, to be substantially fully expanded and thereby achieve a product, suitable for use as a lightweight aggregate, of minimum possible density.