Abstract: An electric arc furnace (1), wherein solids are injected into the furnace chamber. The lances (9, 10, 11) are guided through the wall (12) of the electric arc furnace (1) and inserted into the wall of the furnace, whereby at least one lance is associated with each electrode (2, 3, 4), in order to enable a homogenous formation of slag and to inject as great an amount of solids as possible. The lances are distributed in an approximately uniform manner along the periphery of the furnace. The inclination of the lances and thus the angle of injection are selected in such a way that they form an angle of approximately 30-80° in relation to the flow direction of the melting bath and form an angle of approximately 10-30° in relation to the horizontal.

Abstract: An electrode assembly comprising concentric tubular electrodes is provided for high temperature processing of materials. The electrode assembly is connected with a power supply that includes switching means for alternatively operating the electrode assembly in a transferred mode of operation, in a non-transferred mode of operation, or according to a controlled sequence of non-transferred and transferred modes of operation. The power supply system includes variable inductors, such as leakage-coupled reactors, for controlling the electrical power supplied to the electrodes for producing a DC arc. The electrode assembly can be incorporated into an arc furnace for processing waste material in the furnace. The electrode assembly is also suitable for use in the practice of in-situ vitrification and remediation of contaminated soil.

Abstract: The invention pertains to a process and to a device for supplying current to an electric-arc melting unit for melting and heating metal, especially steel, with a three-phase a.c. source, which sends the current via devices for producing direct current or alternating current to at least one electrode projecting into the vessel of the melting unit. The three-phase a.c. source (91) is followed by at least two power supply modules (41, 4n), connected in parallel, where each power supply module (41; 4n) has an uncontrolled three-phase bridge (51, 5n), a direct-current intermediate circuit (61, 6n), and a transistor unit (71, 7n) connected in series, and where, downline from the power supply modules (41, 4n) in the current flow direction, a common current-carrying line (31) leads to at least one electrode (21) of the melting unit (11) and away from at least one other electrode (22, 24).

Abstract: A roof (3) for a metallurgical ladle/furnace (L.A.F) (1) comprising a self-supporting structure of metallic pipework (4) defining at least one flow circuit for cooling water, with a lower end having a circular peripheral flange (A), with a cylindrical body member (c) of smaller diameter than the flange (A) located above the flange (A) (in use away from the ladle/furnace), and is provided with an end wall (14) having a plurality of apertures (14) each to receive, in a gas-tight manner, a carbon electrode (8), and an aperture (5) for fume extraction provided in the arcuate wall (16) of the cylindrical body member.

Abstract: A high-frequency device for melting and refining inorganic compounds having a high-frequency oscillation system and a crucible. The high-frequency system includes an induction coil looping around the crucible and at least two oscillator circuits connectable in parallel to the induction coil and providing redundant high frequency energy. Each self-exciting oscillator includes one of the capacitors and the induction coil. The device may further include a power supply, a control cabinet having operating units, and a process control system.

Abstract: The heating effect of a microwave susceptor can be improved by providing a pattern of microwave transparent areas in the susceptor. The transparent areas are preferably circles having a diameter of about 0.5 inch. The distance between adjacent circles is preferably about 0.5 inch. The susceptor may be used to brown and crispen the crust of frozen pizza heated in a microwave oven. The crust of the pizza is browner, especially at its central area, than the crust of pizza heated using a conventional susceptor.

Abstract: Disclosed is an electrode control system for an electric arc furnace having a furnace transformer. The electrode control system includes a current transformer for measuring operating current of the electrode and a voltage transformer for measuring operating voltage of the electrode. An active power transducer is connected to the current transformer and the voltage transformer for calculating active power of the electrode from the measured operating current and operating voltage as a first output signal. A reactive power transducer is connected to the current transformer and the voltage transformer for calculating the reactive power of the electrode from the measured operating current and operating voltage as a second output signal. A programmable control unit is connected to the active power transducer and the reactive transducer for receiving the first and second input signals.

Abstract: A soft heating element, utilizing electro conductive textile threads as a heating means having additional safety functions as TCO (thermal cut-off) and TSL (temperature self-limiting) devices. The thermal cut-off function is achieved through melting of the electro conductive threads at the temperatures above 120° C. and below 350° C., which results in termination of electrical continuity in the heating element. The temperature self-limiting capability is achieved through a heating thread electrical resistance increase during slow elevation in its temperature, which is below its melting point. Methods of electrical and mechanical connection between heating threads and metal conductors, utilizing winding of connections with flexible strands of fibers or wires, with optional subsequent placement of a rigid mechanical fastener over the winding.

Abstract: In a charging material preheater for preheating charging material (60) which is to be charged into a furnace vessel (3), having a shaft (9) which is fixed in a frame structure (20) and which in its upper region has a closeable feed opening (61) for the charging material (60) and a gas outlet and in its lower region a discharge opening for the charging material (60) and a gas inlet, and whose shaft walls (33, 35) delimit a receiving space (62) for the charging material (60) to be heated, the shaft walls (34, 35) are subdivided into shaft wall portions which are individually replaceably fixed in the frame structure (20).

Abstract: A water-cooled panel for the furnace wall and furnace roof of an electric-arc furnace is integrally fabricated of refractory bricks arrayed on the furnace inner wall in multiple regularly spaced rows to be exposed at the end surfaces and cooling water pipes installed between the rows of refractory bricks (2). A furnace exterior side of the refractory bricks and a furnace interior side of a cooling water pipe are overlapped in a vertical direction of the water-cooled panel, and the cooling water pipe is provided in between an upper and lower side of refractory bricks.

Abstract: A quadrilateral assembly in an electric arc furnace wall for providing one or more coherent jets into the furnace and for providing preferably a plurality of post combustion oxidant streams into the furnace, preferably for forming a post combustion oxidant sheet.

Abstract: In order to operate an electric arc furnace (1) in optimum conditions, especially in order to build up and maintain a certain intensity of foamed slag, the amount of slag builder fed into the furnace (1) and therefore the power consumption of the furnace (1) is regulated according to the current received by the electrodes (2) in such a way that a maximum amount of slag builder is initially added in order to build up said foamed slag until the amount of current received by the electrodes (2) is reduced. Subsequently, the amount of added slag builder is reduced until the amount of current received reaches a predetermined set value. The theoretical amount of current received is kept constant by reducing or increasing the added amount of slag builder.

Abstract: An induction furnace includes material between the crucible and the coil to enable easy removal when the crucible needs to be replaced. The material is made up of a slip plane material and reinforcement, and preferably comprises a laminate of flexible mica paper and glass fabric.

Abstract: In a tiltable arc furnace in which a furnace vessel (2) and a portal (4) for an electrode lifting and pivoting apparatus are arranged on a platform (1 and 3) of a furnace cradle which is tiltable by a tilting apparatus and which includes two mutually spaced cradle runner skids (16) which each run on a respective support path (17), wherein the furnace vessel (2) is arranged on a first platform region which is between the cradle runner skids (16) and the portal (4) is arranged on a second platform region which is outside the cradle runner skids (16) the two platform regions are in the form of separate platform portions (1, 3) which are connected together by a hinge pivot (13), the portal platform portion (3) carrying the portal (4) is supported by way of a further cradle runner skid (20) on a further rolling path (21) and is tiltable by the tilting apparatus synchronously with the vessel platform portion (1) carrying the furnace vessel (2).

Abstract: An induction melting system uses a crucible formed from a material that has a high electrical resistivity or high magnetic permeability and one or more inductor coils formed from a wound cable consisting of multiple individually insulated copper conductors to form an induction furnace that, along with its associated power supply, provides a compact design. The system components are air-cooled; no water-cooling is required. The induction melting system is particularly useful for separating metal from scrap, casting molds directly from the induction furnace, and providing a continuous supply of molten metal.

Abstract: A scrap charging apparatus for an electric arc furnace uses a skip hoist to supply scrap to a holding bunker having diverging end walls extending between converging side walls. The containment space for the scrap is increased by this wall arrangement and provides an impetus in the bunker for scrap flow to an underlying scrap delivery chute. The scrap delivery chute is formed by an elongated scrap carrying trough having a greater width than the exit width of the scrap holding bunker for delivering scrap to a charging opining for an electric arc furnace A superstructure supporting the scrap holding bunker at an elevated and lateral spaced location from the electric arc furnace. A ram controlled by a drive incrementally advances scrap along the scrap delivery chute for introducing successive preselected volumes of scrap to a charging opining for an electric arc furnace.

Abstract: A heater cable is wired in combination with a lead cable, the two cables form a pattern wherein the heater cable and the lead cable are spaced by a predetermined distance L, in the range of 0 to 10 mm, from each other and are supplied with opposite flow of current. The heater cable has a core thread, a heating element wire wound in a spiral on the outer surface of the core thread, a fusing layer provided over the heating element wire, a signal wire wound in a spiral on the outer surface of the fusing layer and a protective coating provided over the signal wire. The lead cable has a conductive wire covered at its outer surface with an insulating coating.

Abstract: A microwave control unit that includes an external memory storage for storing, for example, control parameters, cooking parameters, and feature data is described. In one embodiment, the control unit includes a pre-programmed microprocessor coupled to a key panel and a display. The controller also is coupled, for example, to a power supply, sensors, and power switches. The control microprocessor, as is known in the art, includes an on-board memory unit, e.g., a read only memory, for storing the control program as well as control parameters, cooking parameters, and feature data. Under the control of the control program, the microprocessor is configured to control, for example, energy output levels and cooking time based on the operator inputs. The control unit also includes an external model configuration read only memory (EMCR) coupled to the control microprocessor via an external bus. The EMCR also has control parameters, cooking parameters, and feature data stored therein.

Abstract: A homogeneous electrode of reactive metal alloy comprises an ingot with an axially disposed core made from one induction melted heat of the reactive metal alloy and having a diameter “d” and a length “L” and a body having an outer diameter at least 2 times “d” and a length “L”. The ingot body is disposed about the core, and comprises a plurality of induction melted heats of the reactive metal alloy to provide an electrode of the required size. The electrode also includes features for receiving electrical current for arc remelting of the reactive metal alloy to produce a large homogeneous ingot. Remelting may be conducted under vacuum or controlled atmosphere conditions, as required.

Abstract: An electrical oven includes a housing defining an inner space and having a bottom wall, two opposite side walls, a lid that is mounted pivotally on the side walls and that confine the inner space at rear and top sides of the housing, and a front opening for access to the inner space. A door is mounted on the side walls for closing the front opening. The lid is turnable relative to the bottom wall between a closed position, in which the lid confines the inner space at the rear and top sides of the housing, and an open position, in which the lid turns away from the door so as to permit the inner space to be exposed at the rear and top sides of the housing. A locking device is mounted on the lid so as to lock the lid unto the side walls when the lid is at the closed position.