Abstract: A material heating furnace with a heating element formed of corrugated metal strips which are spaced at one of the ends thereof by a jumper strip which is welded or otherwise fastened to the metal strips. Also, terminals are provided which are slotted so as to alleviate stresses due to bending.

Abstract: An improved control system for controlling the position of an upper electrode in a carbon arc lamp. The system has a pulley with a line thereover, and a solenoid core is attached to one end of the line and is movable vertically in a solenoid coil connected in the circuit for supplying discharge current to the electrodes, and a control rod clutch is connected to the other end of the line which normally grasps and holds an electrode control rod on the lower end of which is mounted the upper electrode of the lamp. A balancing weight is provided on the core to balance the weight of the control rod clutch and electrode and a shield is provided around the solenoid coil to shield the arc between the electrodes from the magnetic field of the solenoid coil.

Abstract: The invention relates to a high-frequency furnace whose wall is formed by superposed wall-forming members. This furnace includes in particular an inner tubular wall comprising a zirconia tube (38), an alumina washer (39) laid on the zirconia tube and a silica tube (40) laid on the washer. There is a large groove (41) in a top plate (37) to accommodate the silica tube (40). The furnace also includes an outer tube (36) of silica. This structure makes it possible to accommodate differential expansion of the zirconia and the silica in two separate steps. The axial difference is accommodated at the groove (41) while the radial difference is accomodated at the washer (39). Leakage of inert gas pumped into the chamber during operation can then be maintained within acceptable limits throughout the temperature range. Application to the production of optical fibers.

Abstract: An electric arc furnace has a plurality of electrodes each supported at one end of an arm, the other ends of which are each coupled to a column supported for vertical movement by means of a cable assembly. A fail-safe assembly is mounted adjacent the column and is coupled to the cable assembly. While tension is maintained in the support cable a linkage assembly normally restrains a biasing spring from moving a clamping wedge into engagement with the column to prevent vertical movement thereof. When tension is lost in the cable assembly the biasing spring is released to move the wedge into engagement with the column.

Abstract: An electric induction heating furnace comprises a crucible having a lower portion for containing a melt and an upper portion for containing slag floating on the melt. The lower portion is surrounded by an electric induction coil below the top of the lower portion and therefore the upper surface of the melt so that the melt can be inductively heated while its upper surface remains relatively quiet to provide a favorable condition for treatment of the melt by the slag. The crucible's upper portion containing the slag has an inside that is electrically conductive and an arcing electrode is positioned above the slag so that arcing power can be applied via that inside and the electrode to an electric arc formed by the electrode with the slag, for heating the slag to prevent its temperature from dropping too low to permit easy deslagging.

Abstract: An airtight metal melting furnace comprises a melting chamber enclosed by a lined metal shell and a refractory roof with a metal cover. An upper electrode and a hearth electrode are introduced into the melting chamber in order for a plasma or electric arc to be developed therein. Mounted above the roof cover is a slot table supporting means for measuring the temperature of the molten metal, means for drawing samples thereof, and means for introducing additives therein, the means being fixed in slots of said table. The cover and the furnace roof are formed with a channel which is shut by a gate. The slot table is mounted for plano-parallel movement, this permitting an alternate arrangement of said means above said channel and tight joining of the channel and the respective means.

Abstract: Graphite heating rods are disposed within a radiant tube which contains nitrogen under pressure to prevent oxidation of the rods. The pressure in the tube is sensed and nitrogen is admitted into or exhausted from the tube depending upon whether the pressure drops below or rises above a safe range. Only as much nitrogen is introduced into the tube as is necessary to replenish that which might be lost through normal leakage and thus only a comparatively small quantity of nitrogen is required to protect the graphite rods.

Abstract: A DC arc furnace having one or more arcing electrodes and a melt contact electrode transversely offset from the arcing electrode is provided on the outside of the furnace with control electromagnets which are supplied with DC for the purpose of keeping the arc substantially axially aligned with the arcing electrode. For more positive control of the arc direction, radiation sensing devices are provided and which are arranged to receive more or less radiation from the arc if it wanders away from its desired vertical alignment with the arcing electrode. In turn, these devices are used to control the power supplied to the control electromagnets to alter the strength of their magnetic flux, so that if it wanders from axial alignment with the arcing electrode, the arc is substantially immediately returned to that alignment.

Abstract: A magnetic detection device for detecting the position of a movable member which is associated with a piece of magnetic material, the movable member being displaceable in a non-magnetic tube. A detection unit fixed outside the tube and including a permanent magnet with pole pieces directed towards the tube and extended portions extending away from the tube. The extended portions may be either in a plane parallel to or perpendicular to the axis of the tube. A dry reed relay is fixed relative to the pole piece with its ends facing the extended portions remote from the magnet. The extended portions may extend from opposite sides of the tube in which case the extended portions are perpendicular to the axis of the tube and the axis of the reed relay has a normal parallel to the axis of the tube. Alternatively, the reed relay is disposed parallel to the axis of the tube in which case the pole pieces are disposed on the same side of the tube.

Abstract: The present invention relates to a new type of electric furnace and process for its use for highest purity melting of certain metals and semiconductor materials, particularly it is well suited for melting materials that would react chemically with standard refractory crucible materials thus potentially resulting in a contamination of such melt.

Abstract: A conventional electric arc furnace is provided with an outlet in a sidewall of the furnace, the inner and outer ends of which are positioned such that the outer end of the outlet is higher than the inner end of the outlet. The outer end of the outlet communicates directly with a graphite electrode having a hollow interior leading from the sidewall of the electric arc furnace to an electroslag furnace positioned below the electric arc furnace. After an initial charge of ore in the electric arc furnace is brought to the molten state with the slag floating on top of the molten metal, the level of molten metal is maintained above the inner end of the slanted outlet and caused to flow through the slanted outlet and hollow graphite electrode to the electroslag furnace. In the electroslag furnace, the molten metal solidifies on a movable base plate positioned at the bottom of the furnace which is slowly withdrawn out of the bottom of the electroslag furnace, thereby continuously forming the desired steel ingot.

Abstract: An apparatus for forming self-sintering electrodes comprises a permanent current-carrying mold for self-sintering electrodes; a charge-feeding tube concentrically disposed within the mold; a power lead; a drive for moving said electrodes, a device for feeding and pressing electrode material; and a supporting cylinder mounted concentrically around the charge-feeding tube, so as to envelope it, the top part of said cylinder being attached to the drive for moving the electrodes and the bottom part supporting the mold. The device for feeding and pressing electrode material is arranged between the charge-feeding tube and the supporting cylinder in the region near their top portions and is attached to a cross beam movable upwards and downwards by means of special mechanisms, e.g. hydraulic cylinders, mounted on the drive for moving the electrodes.

Abstract: A roof in which beams-headers rest on a roof ring and carry loop-shaped tubes suspended from and coupled with the said beams-headers which are running transversely to the framework tubes. Welded edgewisely to the top generatrices of the tubes are metal straps with bricks placed at least in one layer in rows therebetween. The brick end portions rest on the adjacent tubes, so that the brick in each row are disposed with a clearance sufficient to enable thermal expansion of the brick both vertically and horizontally when heated.

Abstract: Disclosed is a vapor source assembly comprising a means for supporting at least one material to be vaporized, a plurality of electron-beam guns for producing electron beams, and a deflecting means for producing a magnetic field to deflect each electron beam through an arcuate path from its electron-beam gun to the material to be vaporized. The deflecting means includes a plurality of pairs of pole pieces positioned such that a north pole piece and a south pole piece, are on opposite sides of each electron-beam gun, and a plurality of magnetic means including magnets for interconnecting the south pole piece of each successive electron-beam gun with the north pole piece of the next successive electron-beam gun so as to form a single magnetic circuit. In preferred embodiments, the electron-beam guns are positioned below the maximum level of material in a cluster of crucibles, and two long pole pieces extend on opposite sides of the crucibles, but no pole piece extends between adjacent crucibles.

Abstract: A melt rate control system for consumable electrode remelting uses a closed loop control system to control electrical power and hence the electrode melt rate. The control equation is purposely adjusted to cause the melt rate to initially exceed the steady state melt rate in a controlled manner to take advantage of the higher permissible melt rate at the bottom of an ingot. Initially, the melting current is held at a steady level sufficiently high to cause the melt rate to exceed the steady state melt rate. The initial current is then reduced in a controlled manner to bring the melt rate to the steady state condition. The length of time and amount of excessive melt rate is matched to the higher permissible melt rate at the bottom of an ingot.

Abstract: An air tight sleeve is adapted to be moved between an inoperative position and an operative position wherein it extends between the top of a crucible of an electroslag melting furnace and the bottom of the furnace head. A seal is formed between the top of the crucible and the bottom of the sleeve and between the top of the sleeve and the bottom of the furnace head so that the atmosphere within the space between the furance head and the crucible can be controlled. Additionally, the sleeve is electrically connected to the bottom of the furnace head and to an electrically conductive water guide within the crucible wall so that the sleeve also functions as the return conductor.

Abstract: A vertical shaft furnace for continuously melting metal materials, such as scrap, copper cathode pieces and the like is disclosed. The furnace comprises an elongated cylindrical melting chamber having an opening in the upper portion thereof for intermittently gravity-charging the furnace with metal pieces, which form a descending metal column in the melting chamber. A plurality of plasma arc generators is mounted in the sidewalls of the melting chamber extending inwardly thereof in a downwardly inclined attitude. The plasma arc torches are arranged in upper and lower vertically spaced planes for respectively preheating and melting the metal charged to the furnace. Protective refractory shrouds are provided which extend inwardly from the inside wall of the melting chamber and at least partly surround the plasma arc torches to substantially prevent damage to the torches by the descending or dropped metal charge.

Abstract: A lamp mounting having a terminal post providing a rest surface for one side of a lamp terminal of normally regular rectangular shape and a clamping member formed for engagement with the opposite side of the lamp terminal for clamping the latter onto the post and a link pivoted to the post and clamping member, and means applying a resilient force to the link for tightening the clamping member onto the lamp terminal and providing a resiliently yieldable engagement of the lamp terminal between the terminal post and clamping member.

Abstract: The rotary drum of reactivation apparatus has spaced-apart helical electrodes disposed in mutually interposed helical state and fixed to the inner wall surface of the drum, these electrodes functioning upon rotation of the drum to propel by screw action active carbon from an inlet end to the other outlet end of the drum as electric power is supplied to the electrodes to cause electric discharge therebetween and conduction through the carbon, which is thereby subjected sequentially to drying, firing, and reactivation as a result of electric discharge effect and the resulting joule heat. Flow of excessive current between the electrodes is prevented by a constant-current circuit in the electric power supply system. Steam can be additionally injected against the carbon to promote the reactivation thereof.

Abstract: This invention relates to an electric furnace and, in particular an electric furnace having graphite rod heating elements electrically connected into more than one series circuit. In this way, the heating elements can be arranged to provide individually controllable heating zones.