Abstract: An enclosable vessel for containing a silicon nitride article during sintering in a furnace to protect the silicon nitride article from thermal decomposition and contamination reactions with furnace materials comprises a closeable walled container formed of a reaction bonded silicon nitride material having an opening to allow interior placement of the silicon nitride article within the walled container. This box is used to replace silicon nitride powder which has heretofore been used to cover silicon nitride articles during sintering.

Abstract: An apparatus such as a crucible furnace for heating a vessel such as a crucible comprises an enclosure surrounding the vessel so that a flow path exists between the enclosure and the vessel which has an outer surface forming the inner boundary of the flow path. The flow path extends all around the vessel. First and second gas fired burners open into the flow path to discharge their hot combustion product gases into the path. Associated with each burner is a respective heat regenerator. When the first burner is in firing mode its emitted hot combustion product gases circulate around the flow path and leave through the second burner, which is in flueing mode, and heat the associated regenerator. Then when the second burner is in firing mode that heated regenerator heats the combustion air used by the second burner.

Abstract: A pyrolytic boron nitride crucible is provided. The crucible contains at least five wall layers consisting of first and second wall layers. The thickness of each of the first wall layers is 5 to 100 microns and the thickness of each of the second wall layers is 1/50 to 1/1 of that of the first wall layer. The total thickness of the entire wall layers is 0.5 to 3 mm. The first wall layer is bonded to and laminated alternately with the second wall layer.

Abstract: An apparatus for producing a sample is disclosed which has a tilting mechanism (12, 14, 22). The tilting mechanism has a crucible holder (70) releasably coupled thereto and a crucible (100), which is provided with a flange (102), is insertable into the crucible (70) so that the crucible can be tilted by the tilting mechanism. A dish (46) is supported by a support (44) so that the tilting mechanism can tilt the crucible (100) to pour the contents of the crucible into the dish (46). Burners (48 and 50) are provided for heating the contents of the crucible (100) and dish (46).

Abstract: A non-ferrous metal smelting furnace including a preheating tower includes a smelting chamber, provided below the preheating tower, a combustion chamber, provided adjacent to the preheating tower, a lower portion of which communicates with the smelting chamber, the combustion chamber being provided with a burner for generating a combustion gas on its upper furnace body, and a gas diffusion mechanism, provided in the smelting chamber, and including retaining members for constituting a plurality of openings distributed between the smelting chamber and the preheating chamber in the preheating tower and for retaining a material in the preheating tower.

Abstract: An improved charging process for an enclosure for melting materials such as blast furnace slags or basaltic glasses. The supply of combustive gas is carried out nonuniformly in order to create a gas circulation velocity gradient in the section of the cupola corresponding to the level of the tap hole, with the lowest circulation velocities meeting in the vicinity of the tap hole.

Abstract: Melting and holding furnace in which melting (1) and holding (2) chambers are separated from one another, and are connected via openings (6). The holding chamber is designed to be deeper in order to receive the melt which flows out of the melting chamber (1). The chimney (18) through which the burnt gases produced during heating of the melting chamber (1) pass is arranged in the cover (14) of the holding chamber (2), namely at the end of the holding chamber (2) opposite to the openings (6).

Abstract: A pyrolytic boron nitride crucible is provided. The crucible contains at least five wall layers consisting of first and second wall layers. The thickness of each of the first wall layers is 5 to 100 microns and the thickness of each of the second wall layers is 1/50 to 1/1 of that of the first wall layer. The total thickness of the entire wall layers is 0.5 to 3 mm. The first wall layer is bonded to and laminated alternately with the second wall layer.

Abstract: A process and apparatus for maintaining the lining of a furnace shell (1) comprising a bottom and a side wall and supported by a floor (2). The shell (1) is composed of two parts adapted to be separated and constituting respectively a bottom (11) and a cooled side wall (12). The side wall (12) is supported directly on a work floor (2) and the bottom (11) on a support (5) movable vertically between an upper operating position of the bottom (11), in line with the side wall (12), and a lower position. After the bottom (11) has been lowered into the lower position, it is moved out of the axis (10) of the furnace to a maintenance station, from which a new bottom (11') is then brought into the lower position, in the axis (10) of the furnace, in order finally to be raised to the upper operating position. The invention applies particularly to arc melting furnaces for steel production.

Abstract: A crucible/susceptor system is described in which the walls of the crucible and the susceptor cavity are sloped outward in an angle sufficient for the force of gravity to exceed the inward pulling forces created by the high surface tension of molten silicon allowing the softened quartz crucible walls to settle into and form to the sloped walls of the susceptor thereby improving heat transfer from the susceptor to the molten silicon and improving the reproducibility of the system.

Abstract: A tool for firing ceramics such as a setter and crucible comprises a ceramic foam body which has a three-dimensionally reticulated structure comprising plural interconnected ceramic strands, and a ceramic setting layer formed on at least one part of the surface of the ceramic foam body.

Abstract: A shaft melting furnace for melting metals is proposed with an interior receiving the molten bath, a charging shaft for supplying the melting stock and a burner supplying heat to the latter. The charging shaft is funnel-shaped and passes into a melting zone of constant cross-section leading to a melting bridge.

Abstract: A multi-outlet burner for heating material. Nozzles are positioned along a longitudinally extending portion of the burner that generally parallels the material surface. Combustion gas and fuel are combined at each nozzle to produce a plurality of flames that are directed in a sweeping direction over the surface.

Abstract: The specification discloses an analyzer for determining the carbon, hydrogen, and nitrogen content of an organic material. The analyzer includes a vertically oriented, U-shaped furnace including a combustion chamber containing a crucible in which the sample is combusted into constituent gases and a reagent chamber containing a reagent through which the constituent gases must pass. A lance extends into the combustion chamber to guide the sample into the crucible and to direct oxygen onto the sample combusting in the crucible. The analyzer further includes an equilibration vessel and means for conveying the constituent gases to the vessel and past CO.sub.2 and H.sub.2 O infrared cells to monitor the products of combustion. Means are provided for conveying the equilibrated gases past the infrared cells to obtain readings relating to carbon and hydrogen content. A doser doses an aliquot of the equilibrated gas into a nitrogen measurement apparatus to obtain a reading relating to nitrogen content.

Abstract: The specification discloses an analyzer for determining the carbon, hydrogen, and nitrogen content of an organic material. The analyzer includes a vertically oriented, U-shaped furnace including a combustion chamber containing a crucible in which the sample is combusted into constituent gases and a reagent chamber containing a reagent through which the constituent gases must pass. A lance extends into the combustion chamber to guide the sample into the crucible and to direct oxygen onto the sample combusting in the crucible. The analyzer further includes an equilibration vessel and means for conveying the constituent gases to the vessel and past CO.sub.2 and H.sub.2 O infrared cells to monitor the products of combustion. Means are provided for conveying the equilibrated gases past the infrared cells to obtain readings relating to carbon and hydrogen content. A doser doses an aliquot of the equilibrated gas into a nitrogen measurement apparatus to obtain a reading relating to nitrogen content.

Abstract: A melting crucible for small amounts of material has a plurality of pouring openings for the discharge of material selectively from the crucible, or comprises a ring member which is connected to a lower crucible portion containing the material, and which has at least one pouring opening for selective discharge of material from the crucible portion.

Abstract: A combination of a smelting-furnace pouring lip and casting gutter, in which the pouring lip and the casting gutter form a substantially closed system from which a discharge system arranged in connection with the smelting-furnace draws the metal vapors and flue gases through the casting pipe substantially completely.

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: Apparatus for moving a vessel heater cover including upper linkage, lower linkage and a bell crank. The bell crank is pivotally secured to the upper and lower linkage. The lower linkage includes first and second pivot points. The first pivot point connects the lower linkage with the cover and the second pivot point connects the lower linkage with the connector link. A source of power is provided for effecting rotation of the connector link about the second pivot. Counterweights may be provided and be pivoted about the second pivot. The first pivot may include a gimbal providing two axes of rotation for the cover disposed generally perpendicular to each other. Compressible insulation in the cover may project downwardly to provide automatic sealing with the vessel cover. The mechanism provides automatic compensation for misalignment between the vessel rim and the cover.

Abstract: A method and apparatus for converting gel-like substances from a gel state to a sol state in which the melting speed can be accurately controlled over a wide range and the apparatus can be easily cleaned. A grid-type heater constructed of rotatable parallel heating pipes is disposed at the bottom of a melting tank. Rotation of the pipes which simultaneously heating them imparts flowability to a heat transfer boundary formed on the side of the gel-like substance. The melting speed is controlled by controlling the speed of rotation of the pipes.

Abstract: The invention is a simple and reliable mechanical arrangement for automatically positioning a thermocouple-carrying rod in a vacuum-furnace assembly of the kind including a casing, a furnace mounted in the casing, and a charge-containing crucible mounted in the furnace for vertical movement between a lower (loading) position and a raised (charge-melting) position. In a preferred embodiment, a welded-diaphragm metal bellows is mounted above the furnace, the upper end of the bellows being fixed against movement and the lower end of the bellows being affixed to support means for a thermocouple-carrying rod which is vertically oriented and extends freely through the furnace lid toward the mouth of the crucible. The support means and rod are mounted for relative vertical movement.

Abstract: A method of manufacturing a rod of crystalline material in a crucible formed at least partly by a fabric of refractory fibrous material.Prior to its use the crucible is subjected to a preparatory treatment consisting mainly of wetting the inner face by means of gallium.Application: Manufacture of rods of semiconductor material.

Abstract: A fuel-fired furnace for melting metal in a more efficient manner, the furnace having a burner with its combustion air being preheated by passage through an air chamber between spaced inner and outer walls of the furnace jacket and by passage through a heat exchanger through which waste combustion products pass. The jacket is double insulated and the burner is cooled by a special arrangement.

Abstract: A crucible, especially for containing melts, has a multichamber construction wherein there is an outer chamber for containing a heat distribution medium and an inner chamber which acts as a receptacle for the melt.

Abstract: A crucible, for use in heating and/or retaining melts at elevated temperatures, includes a hollow holding member composed of a heat resistant material, and a thin-walled insert composed of a substance chemically resistant to oxygen and oxidizing substances and being removably supported in the holding member.

Abstract: An annular crucible for containing molten, inorganic crystalline material in an apparatus for growing a plurality of substantially monocrystalline articles including a plurality of spaced forming members disposed in a ring-like arrangement within the crucible, and a pair of annular resistance heating elements concentric with the annular crucible, one element proximate the crucible inner wall and one element proximate the crucible outer wall. In combination with the annular crucible, a thin, ring-shaped resistance heating element substantially conforming in outside and inside diameters to those of the crucible and being disposed at a predetermined distance above the crucible, the ring element having apertures for passing the monocrystalline articles and having means for an independently controllable heat output.

Abstract: A coating composition and method for vacuum coating inorganic photoconductive material onto a suitable substrate or backing through utilization of the compositions and irradiation heating devices.

Abstract: A direct arc electric furnace having a tiltable base for pouring molten metal from the furnace. A refractory lined hearth supported by the base is pivotal with respect to the base for tilting to a degree greater than that capable by the base. The furnace includes shell refractory lining material supported upon the hearth encompassed by a removable shell. Replacement of the shell lining is accomplished by removing the shell, collapsing the shell lining into the hearth, and tilting the hearth with respect to the base sufficiently to dump the collapsed lining from the hearth into the pit adjacent the furnace. Further, the use of the tilting and removable hearth permits the hearth to be removed from the base, inverted in the pit, and the refractory lining of the hearth may then be readily removed for replacement purposes.

Abstract: An appliance for sterilizing and melting plastic items such as found in hospitals or the like, for example, which appliance includes a chamber containing a foil casing within which the items are placed, and means for heating the chamber for a temperature and time cycle sufficient to soften or melt the plastic items which when cooled will form a solid body of plastic material containing within it other non-melted disposable items such as might have been included with the plastic items.

Abstract: Pieces of steel scrap are charged into a ladle by a magnet on a crane so that the central part of the charge is substantially denser than the peripheral part. A cover having a plurality of natural gas-oxygen burners mounted around its periphery is then placed on top of the ladle to obtain a substantially gas tight container except for a flue opening and some small openings due to a non-tight fit between ladle and cover adjacent the top. The burners direct their flames downwardly parallel to the sidewall of the ladle and the combustion gases are discharged through the flue opening. The flames are reducing in nature and the container is under a positive pressure. The heating is continued until the scrap is at a temperature of at least approximately 1,500.degree.F and preferably approaching the melting point of the scrap. Molten iron in substantially greater weight that the scrap and having a substantially higher carbon content is then poured into the ladle so that the majority of the scrap is melted.