Abstract: A crucible induction furnace is disclosed which is provided with a preventive measure against low melting point metals and having a crucible refractory within an induction coil in a barrel container, in which the crucible induction furnace comprises a coil protection member located between the crucible refractory and the induction coil and which includes at least one air-permeating portion. An air supply pipe is in communication with the air-permeating portion for supplying pressurized air to the crucible refractory. The air permeating portion is disposed to distribute pressurized air having a higher pressure adjacent to the bottom portion of the crucible refractory than to the upper portion of the crucible refractory.

Abstract: An induction furnace (1) for melting and casting purposes has a closed crucible pot (2) with a pot bottom (3) and a cover (4), a crucible (6) housed in the crucible pot and surrounded by an induction coil (7), and an ascending tube (9) reaching into the crucible, through which the crucible can be emptied into a casting apparatus by means of gas pressure. To permit continuous operation and measurements and analyses during operation, the ascending tube (9) is fastened exclusively to the pot bottom (3) and connected with a horizontal delivery tube (11) which is brought through a side wall of the pot bottom (3). Furthermore, above a separation seam (24) between pot bottom (3) and cover (4) a turret (39) with a vertical axis of rotation is disposed, which has a charging air lock (26) for charging the crucible (6) with melt material (27) and a measuring chamber (36). The charging air lock and measuring chamber can be connected alternately with an air lock valve (25) which is disposed on the top of the cover (4).

Abstract: A furnace for cracking of hydrocarbons, comprising one or several tubes through which the hydrocarbons flow during intensive heating and subsequent cracking. The starting material for the process can be e.g. naphtha or propane, mixed with a small amount of steam. When gases flow through the tube or tubes in the furnace, its temperature is increased up to about 850.degree. C. In order to achieve this, the temperature in the furnace compartment is 1100.degree.-1200.degree. C., and the temperature of the gases in the tubes in the furnace can then exceed 1100.degree. C. The tubes are made from an alloy comprising 15-30 weight % chromium, 3-10 weight % aluminum, the remainder of the composition being mainly iron. This alloy allows significant extension of the possible duration of operation without exchange of the tubes. A further improvement can be achieved by the formation on the inner walls of the tubes of a layer of aluminum oxide, obtained by oxidation of the tubes before the furnace is first used.

Abstract: An apparatus for directing electromagnetic flux near an induction coil comprises a loop-shaped member adapted to conduct electromagnetic flux, defining an axis parallel to the central axis of the induction coil and extending substantially the length of the coil. The loop-shaped member acts as a return circuit for minimizing a stray magnetic field external to the coil.

Abstract: The kiln (1) for producing litharge has a thermally insulated tubular body (2) containing, throughout its length, a shaft (30) with paddles acting as an auger. The tubular body (2) is coaxial with an induction coil (11), which heats it. The raw material in powder form (i.e., the massicot) is charged at a first head (9) of the tubular body (2) and is moved forwards by the paddle shaft (30), until it reaches the second head (10), opposite to the first one (9). During the translation the material (massicot) is heated and is oxidated, being converted into litharge.

Abstract: The invention relates to an induction melting furnace 1 for metals which are difficult to melt including an induction coil 2 surrounding the crucible 3 and a mold receptacle 4 surrounded by an annular chamber 5 to hold the cooling agent. The crucible 3 is disposed in a housing 7 provided with a vacuum connection 6. In order to improve the microporous nature, the melt contained in the mold receptacle 4 is compressed by means of a pressure which is build up in the mold receptacle 4 prior to the cooling.

Abstract: An apparatus for melting metallic stock as a crucible in which the metallic stock is received and melted, the stock in the crucible having an axis along which the force of gravity varies, and an inductive heating system which generates an inductive heating field having an inductive power density which varies along the axis. The inductive heating field interacts with the metallic stock in the crucible so that the radiation energy generated by the inductive heating field counteracts the hydrostatic pressure of the melt in the crucible.

Abstract: An apparatus and method for inductively melting a quantity of metal, without having to contain the metal in a crucible, is described. The solid metal to be melted is placed within a first induction coil excited by an alternating current and adapted to provide a greater electromagnetic force towards the lower portion of the quantity of metal. The solid metal rests on a support, having an opening therethrough, which also comprises means for keeping the support at a low temperature relative to the metal as it melts. When energy in the form of the alternating current is provided to the coil, the metal melts from the top downward, but the concentration of electro-magnetic force towards the bottom of the metal causes the liquid metal to retain a cylindrical shape. A non-varying electromagentic field is applied to the quantity of metal to minimize violent stirring of the molten portion of the quantity of metal caused by the time-varying field.

Abstract: Two coils between which a sample is contactlessly held in a suspended state, form a common part of two different oscillating circuits. A heating oscillating-circuit consists of the two coils and two first capacitors. A positioning oscillating-circuit consists of the two coils and two second capacitors. The current of the heating oscillating-circuit flows through both coils in the same direction, and the current of the positioning oscillating-circuit flows through both coils in opposite directions. Since the two oscillating circuits are not coupled to each other, heating efficiency and positioning efficiency can be set independently from each other. Two coils are sufficient for heating and positioning.

Abstract: Two coils, between which a sample is kept in a contactless suspended state, are connected to separate power sources, at least one of which comprises a phase shifter. Both power sources are controlled by a common oscillation generator. If both currents in the coils are in phase, a magnetic dipole-field of high heating capacity is obtained. If the two currents in the coils are in counterphase, a quadrupole-field is obtained, which generates a high positioning force. By modifying the phase difference, it is possible to generate optional superpositions of the dipole-field and the quadrupole-field, whereby the parts of heating capacity and positioning capacity can be varied.

Abstract: An improved rotary kiln having an elongated kiln member formed of refractory material and supported for rotation, a tubular liner in the kiln member formed of electrically conductive material, a stationary tubular structural non-electrically conductive member concentrically surrounding the kiln and of interior diameter greater than the exterior diameter of the kiln providing an annular space therebetween, an induction coil wound on the exterior of the tubular structural member and an AC source connected to the induction coil and means of rotating the kiln member, the induction coil heating the tubular liner to heat contents within the kiln as the contents are tumbled by rotation of the kiln.

Abstract: An apparatus and process for producing coke in a vertical furnace having an upper part for preheating and devolitalizing raw ovoids of coal, an electrically heated median part for carbonizing and coking the ovoids and a lower part for partially cooling the coked ovoids by counter current flow of recycled product gases recovered from the upper part of the furnace. A cooling chamber is connected to the lower part of the furnace for further cooling the coked ovoids by countercurrent flow of a portion of the recycled product gases which are withdrawn after flowing through the partially cooled coked ovoids and introduced into the upper part of the furnace to prevent condensation of condensibles contained in the product gases. The median part of the furnace may be electrically heated by electrodes, induction coils or a combination of electrodes and induction coils.

Abstract: A method and device are provided for producing refractory materials by induction, in which process a mixture of material powders and a binder in solution in water are compacted by extrusion so as to form a solid bar. The bar is introduced into a cold crucible and is caused to melt by magnetic induction. The molten material flows through a lower orifice of the crucible. The invention applies more particularly to the melting of tungsten carbide.

Abstract: A crushed powder metal workpiece preform is enclosed in a shell or envelope of a ceramic liquid die material and is inductively heated through the ceramic material and then transferred to a pressure vessel wherein the liquid die material is pressurized to provide a rapid omnidirectional compaction of the powder metal preform and thus a fused powder metal workpiece.

Abstract: A packaging system for an induction furnace has an equipment housing within which is located all the operating equipment for the furnace. The equipment is centrally located within the housing and is reached by access panels in the housing cover, which forms a deck. The operating equipment is fully enclosed and protected by the housing, yet can be easily reached by means of the access panels for maintenance, troubleshooting and the like.

Abstract: A packaging system for an induction furnace has an equipment housing within which is located all the operating equipment for the furnace. The equipment is centrally located within the housing and is reached from either side by access panels in the housing cover, which forms a deck. The operating equipment is fully enclosed and protected by the housing, yet can be easily reached by means of the access panels for maintenance, trouble shooting and the like.

Abstract: An induction furnace (60) for reflowing a portion of an optical preform (12) in order to draw a lightguide fiber (11) therefrom includes a tubular susceptor (80) which is disposed centrally within a beaker (75) and a sleeve (82) which is disposed concentrically about the susceptor. The sleeve is spaced from the susceptor and is surrounded by insulating grain (83). A high frequency coil (84) is energized to couple its electromagnetic field to the susceptor to heat and reflow a portion of the preform. The movement of contaminating particles of the insulating grain into the interior of the susceptor is prevented substantially by annular, felt-like discs (91, 105) at the bottom and top of the beaker. The discs collect particulates which move downwardly and upwardly and because of their compliant engagement with the beaker and with the sleeve, they provide seals at those interfaces.

Abstract: A device for continuously making elongated bodies, particularly rods of glass or optical fibers, includes a melting tube for containing molten material and surrounded by a cooling jacket. Within the cooling jacket exists a high frequency electromagnetic coil for heating and melting the starting material in the melting tube. A plurality of metal wires extending parallel to the axis of the melting tube and being grounded as well as a tube of insulating material are located between the wall of the melting tube and the coil. The melt traverses a heating zone and a refining zone so that a solid elongated body is withdrawn from the bottom of the melting tube.