Abstract: A method of generating a loaded layout in a vacuum furnace corresponding to an actual layout in the vacuum furnace during operation of the vacuum furnace may comprise receiving, via a processor, a visual data of a loading process of the vacuum furnace from a camera; comparing, via the processor, the visual data to a predetermined maximum capacity layout for the vacuum furnace; and arranging, via the processor, the visual data into the loaded layout in response to comparing the visual data.

Abstract: The instant disclosure relates to a device and method for recrystallising a silicon wafer or a wafer comprising at least one silicon layer. The silicon wafer or the at least one silicon layer of the wafer is totally molten.

Abstract: Systems and methods are presented for efficient heating during production of corundum. One embodiment takes the form of a system for processing corundum including a first furnace and a second furnace. The first and second furnaces are sequentially arranged and heat from the first furnace is subsequently used to heat the second furnace.

Abstract: A heater includes a base formed with a receiving space for receiving a fuel material that is to be combusted, and a heating unit. The heating unit includes: a flow guide component disposed on the top side of the base and having a through hole axially aligned and in communication with the opening, and at least one air passage communicated with the through hole and permitting air externally of the flow guide component to flow therethrough into the receiving space via the through hole and the opening; and a heat-radiating pipe disposed to extend upwardly from the flow guide component and disposed to surround the through hole and permitting flow of flue gas resulting from combustion of the fuel material in the receiving space therethrough.

Abstract: An ethylene cracking furnace is provided. The ethylene cracking furnace includes at least one radiant section. The at least one radiant section includes bottom burners and/or sidewall burners, and at least one radiant coil arranged in the radiant section. The radiant coil includes at least an upstream pass tube and a downstream pass tube, the upstream pass tube being configured as an inner tube, and the downstream pass tube being configured as an outer tube surrounding the inner tube and having a closed end. The inner tube defines an inner space forming an upstream flow path. A gap defined between the inner tube and the outer tube forms an downstream flow path.

Abstract: The disclosed embodiments relate to systems and methods for heating a slurry to increase a solids concentration of the slurry while maintaining the viscosity of the slurry below a threshold viscosity. For example, in one embodiment, a system includes a fuel slurry preparation system having a slurry tank configured to hold a fuel slurry, the fuel slurry having a solid fuel and a liquid. The fuel slurry preparation system also includes a heat source and a controller configured to control the heat source to heat the fuel slurry to decrease a viscosity of the slurry below a threshold viscosity.

Abstract: A superheated steam generator includes an introduction section for introducing saturated steam into hollow pipe members arranged as steam flow passages and acting as inductively heated elements, and a discharge section for discharging superheated steam from the flow passages, wherein a turbulence generator is disposed in each of the steam flow passages to accelerate heat transfer to the steam in the pipe members, wherein the turbulence generator is a zigzag bent member disposed in the steam flow passage, and a zigzag bending pitch of the bent member changes from rough to minute from the introduction section to the discharge section.

Abstract: An object of the present invention is to improve substrate processing efficiency. A substrate processing apparatus has a reaction tube that processes a substrate inside, and a heating apparatus disposed so as to surround an external periphery of the reaction tube, so that at least a gas inlet tube is disposed on a side surface in an area in which the substrate is processed inside the reaction tube, and the heating apparatus has a heat insulator that surrounds the reaction tube, an inlet opening formed in the shape of a groove in the heat insulator from the lower end of the heating apparatus so as to avoid the gas inlet tube, and a heating element disposed between the heat insulator and the reaction tube.

Abstract: An evaporator for vaporizing an organic material to be deposited on a flexible substrate where the evaporator includes an evaporation tube having a wall encompassing a cavity for vaporizing the organic material, at least one heating device arranged adjacent to the wall and being adapted to heat the evaporation tube, and at least one nozzle assembly protruding from the evaporation tube. The nozzle assembly further comprises a nozzle cover with an opening, and a shutter for selectively opening and closing the opening of the nozzle cover. The shutter is adapted to have in operation of the evaporation tube a temperature within a shutter temperature range of 140° C. such that the temperature of the nozzle cover is within the shutter temperature range.

Abstract: Provided is a complex sintering furnace to sequentially perform a bake-out process and a sintering process for molding ceramic products. The complex sintering furnace includes: a support frame; a pair of furnace bodies supported on the top of the support frame and having a built-in heat insulator covered by a disc-shaped cover; a pair of rails arranged under the support frame in parallel in a length direction along arrangement of the furnace bodies; a rotating base horizontally transferred along the rails and rotatably connected to bottoms of the furnace bodies when the rotating base is vertically transferred directly under the bottoms of the furnace bodies, the rotating base including a separately rotating setter mounted the top thereof; and an ascending/descending apparatus mounted under the rotating bases and having a ball-screw type rotation shaft to vertically ascend/descend the rotating base at the same time of the separate rotation of the setters.

Abstract: A fired heater tube that is resistant to corrosion and fouling is disclosed. The fired heater tube comprises an advantageous high performance coated material composition resistant to corrosion and fouling comprises: (PQR), wherein P is an oxide layer at the surface of (PQR), Q is a coating metal layer interposed between P and R, and R is a base metal layer, wherein P is substantially comprised of alumina, chromia, silica, mullite, spinels, and mixtures thereof, Q comprises Cr, and at least one element selected from the group consisting of Ni, Al, Si, Mn, Fe, Co, B, C, N, P, Ga, Ge, As, In, Sn, Sb, Pb, Sc, La, Y, Ce, Ti, Zr, Hf, V, Nb, Ta, Mo, W, Re, Ru, Rh, Ir, Pd, Pt, Cu, Ag, Au and mixtures thereof, and R is selected from the group consisting of low chromium steels, ferritic stainless steels, austenetic stainless steels, duplex stainless steels, Inconel alloys, Incoloy alloys, Fe—Ni based alloys, Ni-based alloys and Co-based alloys.

Abstract: Provided is a pyrolysis furnace having a gas flowing path controller with an improved structure. The pyrolysis furnace includes: a silicon substrate; a main body of the pyrolysis furnace; a heating unit that is formed around the main body and controls the temperature of the main body; at least one gas supplying tube through which a gas flows into the main body; and a gas flowing path controller that is installed inside the main body and controls the flow of the gas. As a result, controlling and manufacturing of small-sized nanoparticles with excellent characteristics is possible.

Abstract: A radiant heat transfer system has one or more radiant elements inserted in a radiant source. Radiant elements convert the combustion products from burning fuel into radiant energy. A radiant element may be formed from one or more ceramics and may be used in radiant sources, such as radiant tubes, immersion tubes, heat exchanger tubes, boiler walls, and other radiant heat applications. Each radiant element has a core section defining a longitudinal cavity enabling the insertion of a positioning mechanism. Each radiant element may have one or more normal and/or tangential wings attached to the exterior of the core section. Each radiant element may produce a more laminar or less turbulent flow of combustion products within the radiant source.

Abstract: The invention relates to a radiant-heating device for heating an industrial furnace using radiated heat. A first burner unit (1) comprises a first burner (2), which heats an air mixture by burning a fuel (6), a first air supplier (60), via which the first burner (2) is supplied with fresh air, and a first elongated radiant-heating pipe (20), which includes a rearward end (20a) connected with the first burner (2) and a forward end (20b) spaced from the rearward end (20a) and in which the hot exhaust gas generated by the first burner (2) flows from the rearward end (20a) to the forward end (20b) of the first radiant-heating pipe (20) and supplies heat energy along this path to the pipe wall of the first radiant-heating pipe (20). A second burner unit (1?) is constructed like the first burner unit (1).

Abstract: An object of the present invention is to improve substrate processing efficiency. A substrate processing apparatus has a reaction tube that processes a substrate inside, and a heating apparatus disposed so as to surround an external periphery of the reaction tube, so that at least a gas inlet tube is disposed on a side surface in an area in which the substrate is processed inside the reaction tube, and the heating apparatus has a heat insulator that surrounds the reaction tube, an inlet opening formed in the shape of a groove in the heat insulator from the lower end of the heating apparatus so as to avoid the gas inlet tube, and a heating element disposed between the heat insulator and the reaction tube.

Abstract: The present invention concerns a processing furnace used by the oil industry to heat feedstocks that are to be treated thermally, which is provided with bi-pivotal support columns to carry the radiation exchange tubes which form the coil of radiation exchange tubes. The support columns are provided with a lower bearing and an upper bearing means, which pivot, respectively, on a lower support and an upper guide, in such a way that all the stresses from the support and the radiation exchange tubes are transmitted to the base, causing no thermal stress from bending momentum to be transmitted to the base of the furnace.

Abstract: A reactor combustion control method using a high temperature air combustion technology capable of reducing a temperature difference in a reactor without producing cracking and caulking in reaction tubes and the reactor controlled by using the method, the reactor wherein second burners (8) are disposed in a space formed between two or more reaction tubes (7) adjacent to each other so as to inject fuel in the extending direction of the reaction tubes (7).

Abstract: A method and apparatus for continuing the operation of a fuel fired furnace when the air supply from the blower to the furnace is interrupted by employing a combination of a ventilator and drop door, the ventilator having a power source independent of the blower.

Abstract: A furnace apparatus and method for increasing the productivity and/or quality of reheated products by improving the temperature profile of a furnace for reheating products.

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: An indirect radiant heating device burns gaseous or liquid fossil fuels for the heat treatment of running products, such as bars, tubes, and strips kept in a protective atmosphere. The device includes a radiant cassette of parallelepipedal shape, with a continuous radiating surface whose cross section, in a plane perpendicular to the axis of the cassette, is delimited by a continuous line which falls inside a rectangle whose height/width ratio is greater than 1.5.

Abstract: A bottom heated holder furnace (10) for containing a supply of molten metal includes a storage vessel (20) having sidewalls (22) and a bottom wall (24) defining a molten metal receiving chamber (26). A furnace insulating layer (32) lines the molten metal receiving chamber (26). A thermally conductive heat exchanger block (50) is located at the bottom of the molten metal receiving chamber (26) for heating the supply of molten metal. The heat exchanger block (50) includes a bottom face (55), side faces (56), and a top face (57). The heat exchanger block (50) includes a plurality of electrical heaters (70) extending therein and projecting outward from at least one of the faces of the heat exchanger block (50), and further extending through the furnace insulating layer (32) and one of the sidewalls (22) of the storage vessel (20) for connection to a source of electrical power.

Abstract: A heater having a frame supporting a heater element resistance wire and an in-line thermostat. The in-line thermostat has substantially flat connection terminals or terminals, each having a though hole. A substantially flat blade connects to each thermostat terminal by a single screw. The end of each blade distal from the screw is crimped to an end of the resistive wire or another conducting element. An insulating support mounts each blade to the frame. The blade may have bendable tabs for securing it to the insulating support.

Abstract: A method for heating a zone of an elongate tubular article. A heat resistant, heat transmitting and heat dispersive shroud material is applied to the zone and a hot gas source is applied to the outside of the shroud material to cause heat to be transmitted through the shroud material to the zone.

Abstract: The present invention utilizes extended surfaces, such as studs and fins, on a low-flux surface area of radiant heat transfer tubes in a fired furnace to more uniformly distribute heat flux. The invention increases the overall heat transfer of the tube by increasing heat flux rate for the backside of the tube, for example, and thus decreases the temperature differential between the opposing tube sides.

Abstract: A method and apparatus for post-forming an acrylic sheet using radiant heat are disclosed. The heating apparatus includes radiant heating tubes mounted to a frame and positioned in a heating plane. A support platform is also mounted to the frame. A heating area is defined between the heating tubes and the support platform. The heating area is substantially exposed to the atmosphere, allowing unheated air to exchange with the heated air in the heating area. To use the apparatus, combustible gas is ignited and passed through the radiant heating tubes, such that heat radiates from the tubes to the heating area. An acrylic sheet is placed on the support surface such that the unfinished side of the sheet faces the radiant heating tubes. The entire sheet is positioned in the heating area for a selected period of time. The heated sheet is then positioned in a mold until almost cool. At that point, the sheet is removed and allowed to cool completely.

Abstract: A method and apparatus for combustion of a fuel and oxidant in which at least a portion of a fuel and at least a portion of an oxidant are introduced into an annular region formed by an outer tubular member closed off at one end and an inner tubular member open at both ends concentrically disposed within the outer tubular member, forming a fuel/oxidant mixture. The fuel/oxidant mixture is ignited in the annular region, forming products of combustion therein. The products of combustion are then exhausted through the inner tubular member providing oxidant preheating prior to forming the fuel/oxidant mixture.

Abstract: Radiant tube space heating appliance (FIG. 1) has radiation ducting 10 with one or more inline burners 16 in a branch or branches 12 upstream of common tailpipe 20. An exhuast fan 22 in the tailpipe draws heated gases thought the ducting. A power operated control damper 28 in the tailpipe is actuated in response to sensing of the gas temperature in the tailpipe to reduce the induced flow therein when the temperature is below a certain level to counteract the increased volume throughput of the adjacent fan at lower temperature so that performance burners, e.g. on start up, is not adversely affected.

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 recuperator for furnaces includes a set of tubes, which are installed in a secondary chamber (1) which is located behind a main combustion chamber of the furnace and through which hot fumes can pass from the main combustion chamber towards an outlet. The task of the tubes is to recuperate thermal energy from the fumes by bringing a combustion gas to pass through the tubes on its way to burners in the main combustion chamber. The different tubes of the tube set are designed as individual units (8) each one of which is removably inserted in the secondary chamber (1) through holes in the walls (4) thereof. In the mounted condition each tube has a closed portion projecting into the secondary chamber as well as a portion projecting from the outside of the walls of the secondary chamber, the latter portion having inlets and outlets for cold and preheated combustion gas respectively.

Abstract: A radiant tube assembly comprises a radiant tube having a burner leg, an exhaust leg and a recuperator inside the exhaust leg and in a stream of products of combustion flowing in the exhaust leg. The recuperator has an air intake port at a first end and a mixing baffle at a second, hot end. The mixing baffle causes combustion air and products of combustion to be mixed at the hot end of the recuperator and provided to the burner leg for combustion. The mixing baffle includes a flow director which increases the amount of products of combustion mixed with the combustion air. The mixing baffle can also include a dome-shaped end which extends into the stream of products of combustion for reducing turbulence of the stream of products of combustion flowing in the exhaust leg.

Abstract: With respect to a radiant tube burner to be used for heating a heating furnace or the like, to suppress the generation of NOx accompanying combustion, to make the structure thereof fit for a radiant tube burner equipment, to simplify the control of a fuel supply system and an air supply system, and to prevent the coking. Furthermore, to provide a combustion control scheme appropriate to a radiant tube burner. For these purposes, the present invention placed the respective tips of a fuel nozzle, e.g., pilot burner joint-use nozzle (11), and an air throat (13) in the end of a radiant tube (3) and moreover has a combustion air injection port (33) of the air throat (13) provided to be deviated in contact with or near to the inner circumferential wall surface of the radiant tube (3). In addition, a control device (307) for making a burner burn alternately.

Abstract: A nozzle for a recuperative radiant tube burner system is constructed to provide uniform combustion along the length of the inner tube. The nozzle includes combustion air ports disposed at compound angles and having different axial components to provide staged mixing of air and fuel. The staged mixing produces a combustible mixture along the length of the tube to produce a more uniform flame. The nozzle further has an outer wall disposed normal to the combustion air ports to improve air flow through the ports. A fuel outlet tube has relief ports for continuing fuel flow in the event that a main orifice is plugged, which may result from air pressure fluctuations in the burner system.

Abstract: A recuperator of simple design constructed from a hollow tube. A penetrating tube is formed of a hollow tube, preferably of stainless steel, closed at one end and open at the other end. The open end is cut and welded, or otherwise secured, to a perpendicular hollow tube which introduces and expels ambient air. A divider wall is disposed within the penetrating tube to force introduced ambient air along the length of the penetrating tube before exiting the recuperator. This arrangement exposes the ambient air to the heated surface of the penetrating tube along its entire flow path, substantially twice the length of the penetrating tube. A spiralled strip of 14 gage stainless steel may be disposed within the penetrating tube to enhance heat exchange between the penetrating tube and ambient air flowing there within.

Abstract: A method and apparatus for post-forming an acrylic sheet using radiant heat are disclosed. The heating apparatus includes radiant heating tubes mounted to a frame and positioned in a heating plane. A support platform is also mounted to the frame. A heating area is defined between the heating tubes and the support platform. The heating area is substantially exposed to the atmosphere, allowing unheated air to exchange with the heated air in the heating area. To use the apparatus, combustible gas is ignited and passed through the radiant heating tubes, such that heat radiates from the tubes to the heating area. An acrylic sheet is placed on the support surface such that the unfinished side of the sheet faces the radiant heating tubes. The entire sheet is positioned in the heating area for a selected period of time. The heated sheet is then positioned in a mold until almost cool. At that point, the sheet is removed and allowed to cool completely.

Abstract: A batch type furnace includes a furnace body, a floor being removably attachable to the furnace body for forming a furnace chamber, and radiant tubes being substantially and uniformly arranged in the furnace body and the floor. The radiant tubes are controllable to a predetermined temperature independently of each other. The radiant tubes are made of an alloy having a heat resistance of such a degree as to tolerate quick heating and cooling.

Abstract: A method and apparatus is disclosed for the continuous calcining of gypsum material in a high-efficiency, refractoryless kettle preferably heated by a multiple series of separate immersion tube burner coils, each coil operating within a specific calcining zone inside the kettle. The lowest, i.e., initial, burner tube coil is formed with a low profile to permit use of a small initial gypsum charge, and hence, a quick kettle start-up cycle. That low profile initial burner design also helps keep the agitator motor's load at a minimum during cycle start-up. Due to the immersion tube burner coil construction, no refractory structure for the kettle is required. Also, no separate hot pit structure is required, as the kettle is used to merely hold the material being calcined and no residual heat is present. A relatively thin kettle can be constructed, as it need only withstand relatively low operating temperatures.

Abstract: A tunnel-type conveyor oven having two types of heat sources is provided. The oven includes a conveyor for carrying items through the oven along a conveyor path. The conveyor has first and second opposite sides. A plurality of radiant heaters are located transverse to and extend across the conveyor path. The radiant heaters are spaced apart in a direction of the conveyor path. Each radiant heater includes an inner tube having a wall with a plurality of openings defined therethrough, an open first end and a second end. A burner is directed into the open first end of the inner tube. An outer tube is located around the inner tube. The outer tube has an outer surface which is adapted to radiate heat, a first end and a second end. An exhaust outlet is located on the second end of the outer tube.

Abstract: A radiant heating system 30 comprising a tube 34 for radiating heat having a vacuum pump 40 coupled to an upstream end 35 for introducing negative pressure therein, a plurality of burner assemblies 32 mounted in series along a length thereof for igniting a combustible gas within the tube 34, and a metering element 90 for controlling the firing rate of the burner assemblies 32 under variable negative pressure conditions.

Abstract: A furnace for heating a process fluid stream which includes means for efficiently controlling a flow of the process fluid stream through an adjunct loop of the fluid stream. The adjunct loop comprises a heat exchange system in which a portion of the process fluid stream collects heat from flue gases being emitted from the furnace and donates heat to combustion air being used in the furnace. Valve means is positioned downstream of a pump and in connection with the fluid stream in order to constantly replenish a small portion of fluid in the adjunct loop with fresh process fluid. The positioning of the valve means downstream of the pump permits more efficient control of the heat exchange system. One form of valve means may be a valve which will permit a small amount of fluid to continue to flow between the fluid stream and the adjunct loop during a non-operating mode of the adjunct loop heat exchange component.

Abstract: A furnace for heating a process fluid stream which includes means for precisely controlling the temperature of pre-heated combustion air. The system includes a process fluid stream being heated within the furnace and an adjunct loop fluid stream line which acts as a heat exchange system by communication with the process fluid stream. The adjunct loop comprises a heat collecting leg positionable within the combustion area of the furnace and a heat donating leg positionable adjacent a source of combustion air. Manipulation of the flow of process fluid through the heat donating leg provides control of the temperature of the combustion air and consequently control of the stack exhaust temperature. A valve system, which may be manually controlled or thermostatically controlled responds to a present, or desired, temperature of the stack exhaust.

Abstract: A radiant tube assembly includes a radiant tube having a burner leg with a burner therein, an exhaust leg and a connector leg. A recuperator is located inside the exhaust leg in a stream of products of combustion flowing through the exhaust leg. The recuperator has an air inlet port at the outer end and a mixing baffle at the inner end. The mixing baffle causes combustion air and products of combustion to be mixed at the inner end of the recuperator and the mixture is supplied to the burner for combustion.

Abstract: An apparatus for melting particulate polymeric material includes a melting grid and a molten polymer reservoir beneath the grid. The apparatus has a lateral cross-sectional contour defined by walls. Further included is a distribution device having upper and lower surfaces and adapted to the contour of the molten polymer reservoir, which device is disposed in the molten polymer reservoir in proximity to the grid. The device has an internal reservoir formed between the upper and lower surfaces; a perimetrical surface joining the upper and lower surfaces and providing the device with height; at least two fluid distribution pores, each having one end in communication with the internal reservoir and another end disposed in the circumferential surface; and an injection tube providing fluid flow communication between the internal reservoir and an external supply of fluid.

Abstract: An apparatus for thermally cleaning exhaust air containing combustible components comprises at least one combustion chamber for thermally cleaning an exhaust fluid stream and at least two containers adapted for gases to flow therethrough and containing heat storage material for heating the exhaust fluid stream to be cleaned before it enters the combustion chamber and for receiving heat from the cleaned exhaust fluid stream exiting the combustion chamber. Each of the containers has at least one first opening for connecting the container interior to the combustion chamber and at least one second opening for supplying exhaust fluid stream to be cleaned to the container interior and for withdrawing the cleaned exhaust fluid stream from the container interior. The containers accommodating the heat storage substances can be flexibly configured and, if desired, arranged one behind the other in a row.

Abstract: A combined radiant and convection oven controls the rate at which heat is transferred to an object being dried within the oven by varying the flow rate of convection air delivered to the oven's heating chamber. The radiating surfaces within the oven are heated by a novel arrangement of longitudinally extending ducts, each duct associated independently with a different radiating surface.

Abstract: A burner device of regenerative and alternate combustion type including a pair of burners and a regenerative bed, which permits flow passage changeover to be taken selectively between the pair of burners, via the regenerative bed, by four-way and three-way valves which are simultaneously operated by one actuator. Preferably, both two valves are connected coaxially together. The four-way and three-way valves have a same angle of rotation for executing their respective flow passage changeover actions, but they each have its own inoperative area defined differently from each other to produce a difference in timing for supply of fluid to one of the two burners, thereby providing a lead time for prior supply of air and a delay time for delaying supply of fuel to facilitate ignition in one of the burners during the alternate combustion operation.

Abstract: A heat treatment apparatus according to the present invention includes a process tube which heat rays are able to penetrate, a holding member for holding an object to be treated in the process tube, two temperature regulation plates arranged opposite and close to the object held by the holding member, for regulating an amount of heat rays reaching to the object, a heating unit for heating the object in the process tube, a cooling unit for cooling the object heated by the heating unit, a temperature sensor for sensing temperatures of the two temperature regulation plates, and a controller for controlling the heating unit based on the temperature profile acquired in advance and the temperatures detected by the temperature sensor.

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: A burner device of regenerative and alternate combustion type including a pair of burners and a regenerative bed, which permits flow passage changeover to be taken selectively between the pair of burners, via the regenerative bed, by four-way and three-way valves which are simultaneously operated by one actuator. Preferably, both two valves are connected coaxially together.The four-way and three-way valves have a same angle of rotation for executing their respective flow passage changeover actions, but they each have its own inoperative area defined differently from each other to produce a difference in timing for supply of fluid to one of the two burners, thereby providing a lead time for prior supply of air and a delay time for delaying supply of fuel to facilitate ignition in one of the burners during the alternate combustion operation.

Abstract: The invention relates to a hardening furnace, in particular for sheets of glass (2) and the like. In the furnace, the glass sheets (2) are sustained and transported by a conveyor plane (1) of the roller type above and beneath which plane an upper radiating surface (3) and a lower radiating surface (4) are arranged. The upper radiating surface (3) is composed of a plurality of longitudinal strips (31) arranged side-by-side and parallel to the movement direction of the plane (1), while the lower radiating surface (4) is constituted by a plurality of transversal strips (41) arranged transversally to the said movement direction. Each of the strips (31 and 41) is separated from the contiguous strips and represents the lower and upper walls of chambers (32 and 42) separated one from the other. In each said chamber (32 and 42) there is a device which confers regulatable thermal energy, for example, a radiating tube (15).