Abstract: An object of ceramic or metallic material is manufactured by isostatic pressing of a body preformed from a powder of the metallic or ceramic material, the preformed body (10) then being embedded in glass, for example in a mass of glass particles (16) in a vessel (15) which is resistant to the temperature at which the sintering of the metallic or ceramic material is carried out, the material embedding the preformed body being transferred to a melt having a surface limited by the walls of the vessel, below which surface the preformed body is located, and a pressure necessary for the isostatic pressing of the preformed body then being applied on the melt by a gaseous pressure medium.

Abstract: The present invention relates to an optical sensor element of a solid material for sensing physical quantities such as pressure, which element is excitable to emit photoluminescence on excitation which constitutes a measure of the quantity being sensed. The sensor element comprises a diaphragm which consists of at least two layers applied to an apertured substrate, at least one of which layers has luminescent properties. The luminescence may be sensed by means of at least one optical fiber.

Abstract: A wedging device comprises at least two bodies which are movable in relation to each other, namely a first body having two diverging surfaces and a second body which is displaceable relative to the first body along one of its diverging surfaces. A heat-shrinkable casing, made for example from a tape, sheet or film of polymeric material, is arranged around the movable bodies of the device. When the device is heated, the casing shrinks, causing relative displacement between the first and second bodies and a consequent change in the outer dimensions of the device.

Abstract: A device for heating a fluent material (e.g., gaseous or liquid media, such as air, water, etc.) comprises one or more electrical induction coils arranged around one or more central conduits for the medium to be heated, inside which coils there are arranged rings or spirals of metals which form one or more electrically-closed circuits, possibly after addition of short-circuit parts, which circuits, and possible metallic partition walls at these, are arranged to be inductively heated when the induction coils are electrically energized, heat generated in the heating elements passing to the fluent material flowing through the passageways.

Abstract: Apparatus for preheating scrap material, e.g. scrap metal, comprises heaters, such as air preheaters, scrap containers and air or gas conduits for conveying heated gas from the heaters to the scrap container(s) and back from the scrap container(s). The apparatus is characterized in that the conduit to the scrap container(s) is provided with valve means for diverting the flow of hot air or gas to the container(s), for example during replacement of container(s).

Abstract: To reduce the ohmic losses in a sheet-wound transformer or reactor winding, edge regions of at least some of the turns of the conductor sheet forming the winding are located at a different distance from the geometric axis of the winding compared with the distance from said axis of a central conductor portion in a respective one of said turns. Preferably the conductor sheet in each turn substantially follows the flux lines for the resultant magnetic leakage flux which corresponds to a constant current density in the sheet. For example, the winding may be wound from a metallic foil whose edge regions are folded back on themselves, or end regions of the winding may be provided with inter-turn packings (e.g. of tape) to achieve the desired flared shape of the turns at the ends of the winding.

Abstract: A melt is continuously horizontally cast by causing the melt to flow forwardly while spreading laterally to form a flat product. A magnetic field is directed perpendicularly through the flow where it is thicker so as to form the product with a uniform thickness throughout its width.

Abstract: A thermal recuperator for heating gas supplied to a vessel from which a hot gas is discharged and which allows the pressure in the vessel to be controlled substantially without regard to the pressure drop necessary to cause the hot gas to flow through the recuperator. The invention has particular utility in the case of a metallurgical ladle provided with a ladle heater, the combustion air for which is heated in a recuperator receiving waste gas from the ladle. A conduit for the waste gas leaving the ladle is surrounded by one or more conduits for the combustion air, and an ejector fed with combustion air is arranged at the gas outlet of the waste gas conduit to accelerate the waste gases and facilitate their egress from the recuperator.

Abstract: Bodies of silicon nitride are produced by enclosing a silicon nitride powder in a gas-tight glass casing and subjecting the casing to isostatic pressure using gas as a pressure medium at a temperature of at least 1600.degree. C. and a pressure of at least 100 MPa. The casing is a glass having a high softening point. The casing is evacuated and sealed before compressing. The product may be pre-formed by isostatic compacting at a pressure of at least 100 MPa at a temperature considerably below the sintering temperature. The casing is cooled at a rate of at most 1000.degree. C. per hour and at a pressure of not over 10 MPa.

Abstract: An object of ceramic or metallic material is manufactured by isostatic pressing of a body preformed from a powder of the metallic or ceramic material, the preformed body (10) then being embedded in glass, for example in a mass of glass particles (16) in a vessel (15) which is resistant to the temperature at which the sintering of the metallic or ceramic material is carried out, the material embedding the preformed body being transferred to a melt having a surface limited by the walls of the vessel, below which surface the preformed body is located, and a pressure necessary for the isostatic pressing of the preformed body then being applied on the melt by a gaseous pressure medium.

Abstract: An electric arc furnace has an electrically conductive roof with an electrode opening through which an arcing electrode depends with the opening closed around the electrode by an upstanding tubular electrically insulating refractory column surrounding the electrode and mounting on its top an electrically conductive electrode seal.

Abstract: A horizontally elongated furnace to contain a molten metal flow having one end provided with an inlet and the other with an outlet for the flow. An AC powered channel-type inductor is connected to the furnace side wall at an opening below the level of the metal flow. The inductor may be removably mounted to the furnace.

Abstract: A metal oxide reduction furnace has a shaft holding a verticle column of coke. An electric arc on the side of the lower portion of the column burns a cavity in the coke column and the arc is surrounded by the side wall and inner closed end of the cavity so that high temperatures are obtained. A stream of the metal oxide in particulated form mixed with a reducing agent is projected into the cavity to react endothermically within the cavity and lower the high temperature while reducing the oxide to its metal.

Abstract: A process for preparing crude iron and energy-rich, gases, the raw materials being comprised of iron ore concentrate, carbon-containing materials, optionally oxygen gas and electric energy, comprising the combination of the following operations:1.1: preheating of the iron ore concentrate by means of combustion gases from the combustion of discharged gases from the prereduction according to 1.2 below;1.2: prereduction of the iron oxides of the concentrate preheated according to 1.1 by means of part of the discharged gases from the arc furnace according to 1.3 below;1.3: introduction of the concentrate prereduced according to 1.2 into the plasma zone below the electrode of an arc furnace, which contains a crude iron melt, the temperature of which is maintained above 1300.degree. C.

Abstract: A melt of magnesium-containing nodular iron partially fills an enclosure forming a space above the melt which fills with the vapor of magnesium evaporated from the melt. Magnesium is fed into the space where the magnesium vaporizes and increases the vapor pressure so as to drive magnesium into the melt and increase its magnesium content.

Abstract: A melt reduction furnace has a flat gas-tight roof through which the oxide feeding electrode projects an extent less than usual inside the furnace to reduce its breakage risk, and a side wall gas exhaust opening above an upstanding threshold providing low-velocity gas exhaust while the threshold holds back gas flow with possible dust below the opening.

Abstract: A DC arc furnace has power lines arranged completely symmetrically with respect to the arc so as to prevent the arc from bending angularly.

Abstract: At least one arc furnace and at least one induction furnace are connected to the same AC network, the induction furnace being connected via a controllable alternating voltage converter so as to permit compensation of active power fluctuations in the network caused by operation of the arc furnace and the induction furnace being designed to contain scrap for its inductive preheating before charging in the arc furnace.

Abstract: Pig iron is tapped from a blast furnace into a torpedo in which the iron has a treating agent introduced to it while the iron is electromagnetically stirred lengthwise in the torpedo to uniformly distribute the agent throughout the iron while reducing the tendency for skulling in the torpedo.

Abstract: In a combined process crude iron and a synthesis gas particularly suitable for the preparation of methanol are prepared by supplying iron ore concentrate to the plasma zone between an electrode and a crude iron melt in an arc furnace, while injecting gaseous or volatile hydrocarbons, for example natural gas mainly consisting of methane, into the crude iron melt.