Abstract: A zero-voltage switching ARCP-based converter that is capable of balancing its DC-link capacitor voltages and a method of balancing the voltages of the DC-link capacitors of an ARCP-based converter are disclosed herein. Each phase of the converter comprises a main section, an auxiliary section, and a control section. Main switches of the main section synthesize one or more reference voltage at the output of the phase. The auxiliary section facilitates zero voltage switching of the main switches. The control section provides gate signals for the main switches and the auxiliary switches based on the feedback signals from the converter to control the main and the auxiliary circuits. The method balances the voltages of the DC-link capacitor by utilizing ARCP-based hardware. The disclosed method minimizes switching losses and other EMI problems experienced by other converters.

Abstract: In a method and a device for melting down metal-containing material, preferably fine-particulate metal-containing material, such as sponge iron, in a metallurgical melting furnace (1), wherein, in an interior space (11) of the melting furnace (1), a metal melt (5) and a slag layer (6) floating on top of the metal melt (5) are maintained, the metal-containing material is added by means of a supply means dipping into the slag layer (6) and energy is added in the form of electric arcs (14), the metal-containing material is charged directly into the central region (Z) of the melting furnace (1) by means of at least one charging tube (8) exclusively serving for conveying material via the charging tube outlet (9) of the same, the electric arcs (14) are directed obliquely towards the metal melt (5) against the central region (Z) of the melting furnace (1) and the metal-containing material is melted in the slag layer (6) and a mixed process slag-metal melt is maintained in the region of the charging tube outlet (9).

Abstract: In a method and a device for melting down metal-containing material, preferably fine-particulate metal-containing material, such as sponge iron, in a metallurgical melting furnace (1), wherein, in an interior space (11) of the melting furnace (1), a metal melt (5) and a slag layer (6) floating on top of the metal melt (5) are maintained, the metal-containing material is added by means of a supply means dipping into the slag layer (6) and energy is added in the form of electric arcs (14), the metal-containing material is charged directly into the central region (Z) of the melting furnace (1) by means of at least one charging tube (8) exclusively serving for conveying material via the charging tube outlet (9) of the same, the electric arcs (14) are directed obliquely towards the metal melt (5) against the central region (Z) of the melting furnace (1) and the metal-containing material is melted in the slag layer (6) and a mixed process slag-metal melt is maintained in the region of the charging tube outlet (9).

Abstract: The present invention is directed to a switching device and to a pertaining method for parallel connection of subscriber terminal devices having complex performance features. Subscriber terminal devices connected in parallel are thereby driven in an interface driver via a principal subscriber control and at least one subsidiary subscriber control. Due to the realization of a logical and physical interface between the principal and subsidiary subscriber control, the subscriber terminal devices are connected to one another both connection-oriented as well as with respect to their performance features.

Abstract: In a process for melting down sponge metal (11) in an electric-arc furnace (1) having at least one electrode (6), the sponge metal (11) is introduced into the electric-arc furnace (1) under formation of at least one sponge metal jet (15) which in the immediate vicinity of an electrode (6) hits the bath level (16) present in the electric-arc furnace (1), and for decarburization and/or intermixing the bath and/or charging energy oxygen is blown into the melt (7).

Abstract: Method and system for operating a team configuration in an arrangement formed of a number of telecommunications devices, with the telecommunications devices communicating with one another with equal priority, wherein a real or an imaginary instance exists, in addition to the process instances provided for normal telecommunications operation, for each subscriber in each telecommunications device.

Abstract: In a method and a device for melting down metal-containing material, preferably fine-particulate metal-containing material, such as sponge iron, in a metallurgical melting furnace (1), wherein, in an interior space (11) of the melting furnace (1), a metal melt (5) and a slag layer (6) floating on top of the metal melt (5) are maintained, the metal-containing material is added by means of a supply means dipping into the slag layer (6) and energy is added in the form of electric arcs (14), the metal-containing material is charged directly into the central region (Z) of the melting furnace (1) by means of at least one charging tube (8) exclusively serving for conveying material via the charging tube outlet (9) of the same, the electric arcs (14) are directed obliquely towards the metal melt (5) against the central region (Z) of the melting furnace (1) and the metal-containing material is melted in the slag layer (6) and a mixed process slag-metal melt is maintained in the region of the charging tube outlet (9).

Abstract: In a process for melting down sponge metal (11) in an electric-arc furnace (1) having at least one electrode (6), the sponge metal (11) is introduced into the electric-arc furnace (1) under formation of at least one sponge metal jet (15) which in the immediate vicinity of an electrode (6) hits the bath level (16) present in the electric-arc furnace (1), and for decarburization and/or intermixing the bath and/or charging energy oxygen is blown into the melt (7).

Abstract: A process for burning fuel which is formed of free hydrocarbons and/or fine-grained to dusty solid fuels, with a view to obtaining thorough mixing of the oxygen with the fuel in a manner as free of turbulences as possible, is characterized in that, into a main jet of oxygen or an oxygen-containing gas which is approximately cylindrical or slightly conically widening in the jet direction, several fuel jets oriented in a skew manner relative to the central longitudinal axis of the main jet are blown, which fuel jets are formed to surround the main jet peripherally, penetrate into the main jet and are sucked into the main jet.

Abstract: A plant for producing metal includes a electricity supply system and a direct-current electric arc furnace connected thereto, where in order to make do with an electricity supply system possessing a relatively small short-circuit capacity, the direct-current electric arc furnace has at least two electrodes and the electricity supply system has a system short-circuit capacity S.sub.k which is at least equal to ##EQU1## wherein S.sub.i is the nominal power per electrode and i represents an index for the electrodes that varies from 1 up to the maximum number of electrodes in the direct-current electric arc furnace.

Abstract: A d.c. arc furnace for metallurgical purposes includes two or more electrodes arranged on the furnace vessel and projecting into the furnace vessel. To avoid actions of forces departing from the magnetic fields derived form the currents conducted to the electrodes and effecting deflections of the electric arcs, the electric supply means provided for each of the electrodes are each arranged in the immediate vicinity of the electrode to be supplied, the electric supply means of one electrode being arranged so as to be spacially separated from the electric supply means of the remaining electrodes, viewed in the peripheral direction of the furnace vessel.

Abstract: A scrap-melting electric arc furnace operating at an elevated melting power having a simple construction that also avoids thermal loads of the side wall caused by the electrodes. The electrodes are protected from damage during scrap-charging. The electric arc furnace includes a bottom for receiving a melt. An upper part rises from the bottom part and has side walls. A lid covers the upper part. A charging shaft is disposed approximately centrically relative to the upper part, and has a diameter that is substantially smaller than the diameter of the upper part. The charging shaft interior communicates with the furnace interior via an opening in the lid. Electrodes arranged approximately radially symmetrically are directed obliquely into the furnace interior and project toward the center of the electric arc furnace.

Abstract: This invention discloses an expression system which is useful in industrial Bacilli to produce target proteins which include, but are not limited to, alkaline proteases, amylases, cellulases, lipases or other hydrolyases which are normally excreted outside of the host cell.

Abstract: There is disclosed an electric arc furnace for the production of steel by melting scrap, in particular iron scrap, and/or sponge iron and/or pig iron as well as fluxes in a furnace vessel, into which at least one graphite electrode projects, which is displaceable in its longitudinal direction, wherein an electric arc is ignited between the graphite electrode and the charging stock. To achieve a particularly high energy input, the graphite electrode projects into a lower part of the furnace vessel from aside and the lower part, in the region of the graphite electrode, has an enlargement radially protruding outwardly relative to the upper part.

Abstract: A bottom anode for a metallurgical vessel destined for producing a metal melt is formed by a metal bar provided with at least one through recess extending from outside of the metallurgical vessel as far as to within the metallurgical vessel. In order to substantially increase the service life of such a bottom anode, conforming it to that of a lining made of refractory material, the bottom anode, on the vessel internal-side end of the metal bar, is provided with a nose formed of metal melt produced within the vessel. The nose incorporates channels departing from the vessel internal-side end of the through recess of the metal bar, which is connected to a supply duct introducing liquid and/or solid hydrocarbons, and at least some of the channels reaching as far as the surface of the nose.

Abstract: In the reactor for carrying out chemical reactions with ultrasound, at least three ultrasonic transducers (15) are arranged on the bottom (13) of the reactor (10) and at least six ultrasonic transducers (15) are arranged on the wall (14).

Abstract: There is disclosed an electric arc furnace for the production of steel by melting scrap, in particular iron scrap, and/or sponge iron and/or pig iron as well as fluxes in a furnace vessel, into which at least one graphite electrode projects, which is displaceable in its longitudinal direction, wherein an electric arc is ignited between the graphite electrode and the charging stock. To achieve a particularly high energy input, the graphite electrode projects into a lower part of the furnace vessel from aside and the lower part, in the region of the graphite electrode, has an enlargement radially protruding outwardly relative to the upper part.

Abstract: The invention relates to a method for blowing oxidizing gases into molten metal located in a reaction vessel having tuyeres below the metal bath surface, whereby the oxidizing gases are blown into the molten metal from these tuyeres and fed to the tuyeres at an inlet pressure between 85 bars and 170 bars.

Abstract: In a method of producing metal melts, in particular a steel melt from scrap, in an electric arc furnace having at least one graphite electrode, organic substances are charged into the electric arc through a central longitudinal recess of the graphite electrode so as to reduce electrode consumption.