Abstract: A graphite crucible has a cylindrical body with an upper opening for receiving a sample for analysis and a disk-shaped pedestal base. The pedestal base includes a bottom surface with a centrally formed circular indentation. An inwardly projecting concave arcuate annular indentation extends between the body and pedestal base with a smoothly curved radius of curvature. The upper and lower walls of the arcuate indentation diverge outwardly at an angle of from about 56° to about 60°.

Abstract: An electrode for a resistance analytical furnace has a crucible-engaging surface and an end spaced from the crucible-engaging surface having a plurality of grooves formed therein. A manifold mounted on the end of the electrode defines a dust recovery plenum and includes an outlet communicating with the plenum for coupling to a vacuum source to remove debris from the electrode. The improved electrode and electrode cleaning manifold positioned on the electrode provides a turbulent airflow for removal of dust and debris from an analytical furnace.

Abstract: A combustion tube mounting system releasably mounts a combustion tube to an aperture in the floor of a furnace housing. The combustion tube has a base assembly with a cam and can be manually or automatically unlocked by cam pins in the floor for selectively engaging the cam for lowering the combustion tube from the floor of the furnace. When a new combustion tube is placed on the lower seal assembly and raised, it automatically aligns and engages the upper furnace seal and engages cams on the floor of the furnace housing which lock the combustion tube in place as it is introduced into the furnace.

Abstract: An electrode for a resistance analytical furnace has a crucible-engaging surface and an end spaced from the crucible-engaging surface having a plurality of grooves formed therein. A manifold mounted on the end of the electrode defines a dust recovery plenum and includes an outlet communicating with the plenum for coupling to a vacuum source to remove debris from the electrode. The improved electrode and electrode cleaning manifold positioned on the electrode provides a turbulent airflow for removal of dust and debris from an analytical furnace.

Abstract: A heat processing furnace comprises: a processing vessel for receiving an object to be processed by a heat process; a cylindrical heat insulation member surrounding the processing vessel; a helical heating resistor arranged along an inner peripheral surface of the heat insulation member; a support member for supporting the heating resistor. The support member includes a base part positioned on an inside of the heating resistor, and a plurality of support pieces extending radially outward from the base part through spaces between adjacent portions of the heating resistor so as to support the heating resistor, the support member being formed to have a comb-like shape. An upper surface part of each of the support pieces is formed to have a curved shape in order to reduce a frictional resistance generated when the heating resistor is moved upon a thermal expansion and a thermal shrinkage thereof.

Abstract: A heat-processing furnace comprises: a processing vessel for housing an object to be processed to thermally heat the object to be processed; a cylindrical heat insulating member surrounding the processing vessel; a helical heating resistor disposed along an inner circumferential surface of the heat insulating member; and support members axially disposed on the inner circumferential surface of the heat insulating member, for supporting the heating resistor at predetermined pitches. A plurality of terminal plates are disposed outside the heating resistor at suitable intervals therebetween and attached to the heating resistor, the terminal plates radially passing through the heat insulating member to be extended outside. A plurality of fixing plates are disposed outside the heating resistor at suitable intervals therebetween and attached to the heating resistor, the fixing plates being fixed in the heat insulating member.

Abstract: A high-temperature furnace for melting materials, e.g. silicon, wherein the furnace comprises a vessel having a wall which defines an inner chamber. A crucible containing the material to be melted is positioned inside of the chamber and heating means is arranged around the crucible. An insulation package is provided in the chamber for protecting the vessel wall from the heat generated by said heating means. Specifically, the package comprises a support ring of insulation mounted in the chamber, a sleeve of insulation supported on the ring and extending upward between the heating means and the vessel wall, a catch tray adapted to receive any material which may leak from the crucible during heating mounted through the support ring, and a top and a lower layer of insulation to thermally seal the crucible within the package during heating.

Abstract: Oven for non-metal melting, in particular silicon melting, with a housing enclosing an interior, at least one mould arranged in the interior for receiving a non-metal melt, at least one electrical heating device enclosing, at least partially, the at least one mould for influencing the temperature of the non-metal melt, and a power supply device connected in an electrically conductive manner to the at least one heating device for providing the heating device with a time-variable current I(t), wherein the current I(t) has a frequency of 0.1 Hz to 1000 Hz and the current I(t) is of a magnitude sufficient for setting a predetermined temperature of the non-metal melt, the currents in the plurality, where necessary, of heaters having a defined phase position in respect of one another.

Abstract: In order to provide a magnetic rotation transmitting device capable of obtaining a large transmitting torque without using a large-sized permanent magnet, in an axial-type magnetic rotation transmitting device, which includes a driving rotation body having one or plural magnetic line(s) in which plural first magnets (10A) are disposed in a circumferential direction on a first disk (11A) at almost equal intervals, a drive source rotationally driving a drive shaft of the driving rotation body, and a driven rotation body having one or plural magnet line(s) in which second magnets (20A) of the same number as the first magnets (10A) are disposed in the circumferential direction on a second disk (21A) at almost equal intervals, symmetrically disposed to, and magnetically coupled with the driving rotation body with a magnetic coupling gap and, which utilizes a magnetic operation and which allows the driven rotation body to rotate by rotationally driving the drive shaft by means of the drive source, the first magnet

Abstract: The invention relates to an arrangement for mounting electric heating elements in a furnace in which objects are intended to be heated, wherein the furnace wall includes a furnace insulation (4) comprised of high grade brick, and wherein the heating zones (6) of respective electric heating elements (2) are placed vertically and parallel with the inner surface of the furnace wall in operation.

Abstract: Blocks of organic material (58) are fed from a plurality of directions into a reactor (10) having three zones (16, 18, 19). The material forms a bed (70) atop a bed of consumable carbon catalyst (60). These beds are heated by a series of plasma arc torches (42) mounted in inlets (37) about the reactor. Gas is supplied via inlets (39, 41) from wind drums (38, 40). The superheated gas from the reaction is vented through an outlet (30) and is used to produce electrical energy.

Abstract: The aim of the invention is to provide a means of also cooling the lower part of electric arc furnaces and/or resistance furnaces. To this end, said lower part—the actual melting vessel (4)—is surrounded with a jacket (9) at a certain distance, forming a shell, and the resulting intermediate space is configured as a cooling device (10) and subjected to the action of a cooling medium (14).

Abstract: An improved apparatus and method for thermal processing of semiconductor wafers. The apparatus and method provide the temperature stability and uniformity of a conventional batch furnace as well as the processing speed and reduced time-at-temperature of a lamp-heated rapid thermal processor (RTP). Individual wafers are rapidly inserted into and withdrawn from a furnace cavity held at a nearly constant and isothermal temperature. The speeds of insertion and withdrawal are sufficiently large to limit thermal stresses and thereby reduce or prevent plastic deformation of the wafer as it enters and leaves the furnace. By processing the semiconductor wafer in a substantially isothermal cavity, the wafer temperature and spatial uniformity of the wafer temperature can be ensured by measuring and controlling only temperatures of the cavity walls.

Abstract: A sample introduction system includes a drop chamber which can be sealed and outgassed and which includes a movable jaw selectively holding the sample in position above a conduit communicating with an open crucible for receiving a sample once the jaw has been moved to an open position releasing the sample. The jaw is actuated by a magnetic field which moves the jaw in an entirely enclosed system, thereby preventing the introduction of atmospheric contaminants during the operation of the sample dropping jaw from a closed, sample holding position to an open sample releasing position. By providing a magnetic actuator, such as a solenoid, for operation of the jaw, the sample chamber remains sealed during the sample dropping operation preventing contaminants from interfering with the analytical results.

Abstract: An improved apparatus and method for thermal processing of semiconductor wafers. The apparatus and method provide the temperature stability and uniformity of a conventional batch furnace as well as the processing speed and reduced time-at-temperature of a lamp-heated rapid thermal processor (RTP). Individual wafers are rapidly inserted into and withdrawn from a furnace cavity held at a nearly constant and isothermal temperature. The speeds of insertion and withdrawal are sufficiently large to limit thermal stresses and thereby reduce or prevent plastic deformation of the wafer as it enters and leaves the furnace. By processing the semiconductor wafer in a substantially isothermal cavity, the wafer temperature and spatial uniformity of the wafer temperature can be ensured by measuring and controlling only temperatures of the cavity walls.

Abstract: A graphite furnace element, such as a heat shield or heating element, comprises a plurality of bent, rigid, solid and arcuate-shaped graphite sheets that have been joined together, usually by screws or bolts. The bent graphite sheets typically have a wall thickness between 0.05 and 0.5 inch.

Abstract: A coal/coke sample is heated under controlled circumstances as a step in determining content of volatile matter. The sample is placed in a crucible having a lid and which is suspended by means of a crucible holder in a heating cavity of a furnace. The invention provides precisely, mechanically guiding the crucible holder and crucible into and out of the cavity to prevent inadvertent touching of the cavity wall by the crucible and thus also to prevent possible dislodging of the lid and spoiling of the sample. The crucible holder is secured to a lid of the furnace, and the furnace lid is guided along upwardly extending guide rods. Lifting and lowering of the lid may be manually. Instead, it may be hydraulically or pneumatically.

Abstract: A method and apparatus for heat-treating a material at high temperatures wherein the material from which the bottom of a furnace chamber is made forms a eutectic with the material to be heat-treated, and does so at a temperature lower than the heat treatment temperature. A part of the furnace chamber bottom, which part can include the whole or a portion of the furnace chamber bottom, and on which the material to be heat-treated rests is formed at least in part of a material that has the same chemical composition as, or a chemical composition similar to, the chemical composition of the material to be heat-treated. The furnace bottom part on which the material to be heat-treated rests is positioned so that it has no physical contact with the remaining furnace bottom material within the furnace chamber.

Abstract: An improved process and apparatus for the production and reactivation of activated carbon comprising the passing of a substrate through one or more zones defined by electrodes. Electrical energy passing through the bed of substrate creates heat that supports the devolatilization and activation of the substrate. Steam, carbon dioxide, or an alternative gas can be used to support the activation process, while other zones can be filled with inert gas such as nitrogen to promote pyrolysis reactions. Preferably, these gases pass through the bed in a co-current downward flow with the carbon to prevent fluidization and arcing within the bed.

Abstract: The invention relates to an electric resistance melting furnace for vitrifiable compositions, such as glass, enamel or ceramics, with a rotatable melting tank (1) about the vertical axis and a stationary upper furnace (4), which can be operated intermittently or continuously and permits a rapid and clean product change.

Abstract: An electrically heated furnace includes an inner furnace chamber provided with heating elements of stabilized zirconium dioxide, and an outer furnace chamber in which further heating elements that can work at temperatures above 1800.degree. C. in an oxygen-containing atmosphere are provided. The outer heating elements are conveniently of a molybdenum silicide type, for instance elements marketed under the designation KANTHAL Super. Those walls that define the inner furnace chamber are made of zirconium dioxide material or some other suitable material that has a low specific thermal conductivity and that is capable of withstanding the high working temperature and the occurrent temperature swings. The outer furnace chamber, which completely surrounds the inner furnace chamber, is separated from the surroundings by conventional walls insulated, e.g., with ceramic fibres and/or high-temperature durable brick.

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 sheet of high strength graphite material is bent into an arcuate shape, and the bent sheet is retained in that shape for use in a high temperature furnace. The bent sheet is rigid and can replace prior art machined blocks of lower strength graphite in a furnace. The bent sheet can also be further machined and/or further deformed into other shapes.

Abstract: A flat, elongate, trough-shaped part (8) made of an electrically conductive ceramic can be heated by the direct passage of current between clamping points at opposite ends. The trough-shaped part (8) being provided with openings (12) for reducing cross sectional area where increased ohmic heating is desired, such as near the clamping points and between individual areas where wire is fed for melting in the trough.

Abstract: A heating element for heating crucibles, including a cylindrical hollow body which is divided by slits into meandrous segments. The corners between adjacent lateral surfaces of the meanders are rounded. Sectional transition areas are located in the vicinity of the upper and lower edges of the meandrous segments. Each sectional area has an outer rounded edge with a radius of curvature equal to the individual length of each meandrous section.

Abstract: A method and apparatus for heating a metallic material held by a holder such as a crucible which is positioned on a base using an electric furnace. The electric furnace includes a sleeve, an electric heating element disposed on the inner surface of the sleeve, a removable lid for covering a top opening of the sleeve and at least one handle disposed on the outer surface of the sleeve for lifting and removing the sleeve from the base or placing the sleeve on the base. When the sleeve is placed on the base enclosing the crucible, the removable lid is placed on the top opening of the sleeve and an electric current is applied to the electric heating element. Heat generated by the electric heating element and retained in the furnace melts the material contained in the crucible.

Abstract: An inexpensive crucible capable of obtaining a high analytical accuracy is provided. A circular projection is formed in a portion above a portion having an intermediate height on an inner circumferential surface of the graphite crucible to prevent contamination of the sample gases.

Abstract: A high strength graphite material is fabricated into a sheet, the sheet is bent into a tube, and the tube is retained in that shape for use in a high temperature furnace. The retained tube is rigid and can replace prior art machined blocks of lower strength graphite in a furnace. The tube can also be further machined and/or further deformed to achieve more complex shapes.

Abstract: An electrical resistance heated oven is used to heat a crucible to melt a sample and to simultaneously heat a casting dish into which the molten sample can be poured. The oven is cooled with the crucible and casting dish within the oven in order to prepare a sample bead for analysis. In another embodiment of the invention the sample is again melted in a crucible and after melting the crucible is moved out of the oven and turned to pour the molten sample into an acid solution positioned external to the oven. The crucible and sample can be moved while in the oven to mix the sample. The method of preparing an analytical sample using the electrical resistance heated oven is also disclosed.

Abstract: An interchangeable module for supporting a receptacle into which a molten sample, prepared by a fluxer, can be poured for analysis. One module can support a resistively heated casting dish into which a molten sample can be poured and cooled to form a solid sample for instrumental analysis. This module includes an insulator having a depression for receipt of a casting dish. A heating coil is positioned below the recession. A cooling gas conduit extends through the insulator support. The insulator is supported on a frame. The frame is supported on a back plate.

Abstract: An evaporator boat for an apparatus for coating substrates in a vacuum coating chamber consists of a shallow, trough-shaped piece of an electrically conductive material, the boat being heated by direct passage of current through it. The evaporator boat has an elongate hexagonal plan, the configuration of the recess within the boat for containing the material to be evaporated corresponding approximately to that of the boat. Lengthwise opposed ends of the evaporator boat are provided each with an approximately rectangular, perpendicular flat area. The flat areas together form two directly opposed parallel clamping surfaces of the evaporator boat so that when the evaporator boat is heated, two active evaporating zones form on both sides of the point of contact between the delivered wire and the evaporator boat.

Abstract: A plasma ashing apparatus has a vacuum treatment chamber for receiving therein a substrate coated with a resist film, a reactive gas introduction pipe equipped with a plasma applicator, a vacuum exhaust pipe, a heating means for heating the substrate, and two pieces of electrodes disposed in parallel to each other. One of the electrodes is a substrate electrode and the other thereof is a circular counter electrode. These two electrodes are commonly connected to an RF power source to thereby constitute a cathode electrode. Multiple concentric perforations are formed in the counter electrode except for a rib portion. A central perforation is formed in the center of the counter electrode. The concentric perforations are formed at every distance, from the center, equivalent to a diameter of the central perforation, while leaving circular electrode surfaces corresponding in width to a radius of of the perforation.

Abstract: The invention relates to a tape vapor coating apparatus for the production of film webs 50 coated in a vacuum, with a coating chamber for the accommodation and advancement of a film web 50 as well as an evaporation source 19 provided in the housing and having at least one evaporating cell 21, at least one recess 15 being provided in the evaporating cell 21 to accommodate the substance that is to be evaporated. In the recess 15 of the evaporating cell 21 for the accommodation of the substance to be evaporated there is provided an additional, groove-like recess 14.

Abstract: In an apparatus and process for the activation of carbon from carbon feedstocks by electrical resistance heating in the presence of steam, which comprises preheating particles of the carbon feedstock in a preheater, having the particles descend by gravity into and through a vertical reactor connected to the preheater, introducing steam at the bottom of the reactor so that it moves upward against the downward flow of the particles, passing an electric current through the particles in the reactor, and discharging the activated carbon from the bottom of the reactor, the improvements that comprise feeding the carbon feedstock through the side of the preheater, controlling the electric input, having the reactor project into the preheater, using a knife-gate valve and a discharge-limiting device to control the discharge of the activated carbon, using a carbon feedstock that contains up to about 25% of organic volatiles, maintaining the preheating temperature within a range from about 550.degree. C. to about 750.

Abstract: A refractory heat-insulating graphite sheet material characterized in that the material comprises a graphite sheet.

Abstract: A molecular beam source suppresses a temperature fall at the opening of a crucible, to make a temperature distribution within the crucible uniform and to prevent the phenomenon of bumping of a source substance, whereby the quality of an evaporated film can be enhanced. The source includes a heater disposed around the crucible which is formed of straight parts and U-shaped end parts continuously repeated at equal intervals. The straight parts are arranged so as to extend in a vertical direction of the crucible and the U-shaped end parts are bent outwards at outer-peripheral positions of the opening of the crucible.

Abstract: A crucible of a resistive material has a smoothly rounded inner bottom and a radially outer portion of the outer bottom having a rounded shape. The shape of the outer bottom bears a predetermined relationship to the shape of the inner bottom. In one embodiment of the invention, the outer bottom and inner bottom have a common radius of curvature, whereby the thickness of material between the outer and inner bottom is constant. In a second embodiment of the invention, the centers of curvature differ, whereby the resistivity of material at differing radii is tailored.

Abstract: A furnace for extracting gaseous components from material samples includes upper and lower electrodes mounted to press therebetween a crucible of electrically conductive material. An electric current is applied to the electrodes, thereby causing heating of the material sample contained in the crucible, with the result that gaseous components are extracted from the material sample. At least one of the upper and lower electrodes is rotated about a vertical axis, thereby causing surfaces of the crucible contacting respective surfaces of the upper and lower electrodes to rotate under friction against such respective surfaces, thereby improving electrical contact between the crucible and the electrodes.

Abstract: An improved heating fixture, wherein the support means upon which a workpiece to be heated is mounted, is a vitreous carbon plate. The use of a vitreous carbon support plate significantly reduces the time required to heat and cool the support plate and a workpiece thereon.

Abstract: An electrode assembly includes an electrode and a crucible-supporting insert releasably secured to the electrode. In the preferred embodiment a collar is threaded onto the electrode and has tabs extending inwardly to clamp the insert to the electrode. A small button-like projection on the electrode may be provided and is received within an aperture in the insert to center the insert on the electrode.

Abstract: A control system for applying operating power to an analytical furnace includes a first circuit providing output signals consisting of a series of binary bits in a predetermined pattern with each bit corresponding to a unit of power to be applied to an analytical furnace according to the pattern of bits and a control circuit coupled to the first circuit and including output terminals for coupling the control circuit to an analytical furnace. The control circuit responds to the binary bits to provide pulses of operating power to the output terminals in a sequence corresponding to and controlled by the binary bits. The pattern of bits provides stepwise increasing temperature levels for the analytical furnace in a very predictable and controlled fashion such that samples combusted by the furnace will emit specimen gases associated with different compounds containing the specimen gas at different temperature levels.

Abstract: An automatic cleaning device is employed in an extracting furnace of an apparatus for analyzing gases in metals, the furnace including upper and lower electrodes relatively movable between a closed position, whereat a crucible containing a sample to be analyzed may be contacted and heated by the electrodes, and an open position, whereat the electrodes are spaced from each other. The automatic cleaning device cleans the upper and lower electrodes and includes a support bracket mounted for movement laterally of the electrodes. A cleaning unit is supported on the support bracket and is movable thereby between a first position located laterally of the electrodes and a second position located between the electrodes. The cleaning unit includes a crucible removal device to remove a spent crucible from the electrodes upon movement of the cleaning unit to the second position thereof. The cleaning unit includes upper and lower brushes rotatable to clean the upper and lower electrodes.

Abstract: A sample loading mechanism includes a hopper mounted to a base for positioning the hopper with respect to a furnace for releasably holding a relatively small sample in relation to a crucible used with the furnace. The hopper includes a floor with a movable element for alternately closing the floor for holding the sample and opening the floor permitting the sample to drop into the crucible. A plate is slideably mounted to the base above the hopper and includes an aperture which aligns with the hopper in a first position for admitting a sample to the hopper and is slideable to a second position for selectively sealing the upper end of the hopper. An actuator is provided for selectively controlling the movable element of the hopper for dropping the sample into a crucible aligned below the hopper.

Abstract: A crucible assembly for use in an analytical furnace for the fusion of a sample includes a graphite heating crucible of cylindrical construction having one end open and an enclosed lower end with a positioning member interior to the interior cylindrical wall for receiving and positioning a separate sample holding crucible of cylindrical construction having an open upper end and an enclosed lower end. The heating crucible has an annular upper contact surface for engaging a first electrode and an annular lower contact surface for engaging a second electrode and positions the sample holding crucible in the zone of maximum heat in spaced relationship from the opposite ends of the heating crucible.