Abstract:
This invention relates to a method for the thermal treatment of granular solids in a fluidized-bed reactor (1), in which microwave radiation from a microwave source (2) is fed into the reactor (1), and to a corresponding plant. To improve the utilization of energy and the introduction of the microwave radiation, a first gas or gas mixture is introduced from below through a preferably central gas supply tube (3) into a mixing chamber (7) of the reactor, the gas supply tube (3) being at least partly surrounded by a stationary annular fluidized bed (8) which is fluidized by supplying fluidizing gas. The microwave radiation is supplied to the mixing chamber (7) through the same gas supply tube (3).
Abstract:
The invention concerns composites substantially consisting of: a cermet material having a binder metal phase of between 5 and 30 mass % and the remainder comprising at least one carbon nitride phase; or a hard metal with a hard material phase of between 70 and 100 %, the remainder being a binder metal phase, with the exception of a WC-Co hard metal, with up to 25 mass % cobalt as binder metal; or a powder-metallurgically produced steel. The invention further concerns a process for producing this composite. In order to improve bending strength and hardness, sintering is carried out in a microwave field.
Abstract:
The invention concerns an oxide-free composite body with a binder metal phase and with at least one hard phase substantially consisting of: a cermet material with a binder metal phase of between 3 and 30 mass %, the remainder being at least one carbonitride phase; or a hard metal with at least one hard material phase of between 65 and 99 mass %, the remainder being a binder metal phase. The metals necessary for forming the hard phase, the carbon and optionally further metals and metallic carbides and nitrides and/or solid nitrogen compounds as suppliers of carbon and/or nitrogen, each exclusively in powder form, are compacted to form a green compact and then, either at a pressure of Pa or preferably without pressure, are subjected to reaction sintering in a microwave field, in which the resultant hard phases form a fluid phase with the remaining other substances not involved in the hard phase reaction. The invention further concerns a method of producing the composites according to any one of claims 1 to 16, characterized in that the metals necessary for producing the hard phase(s), the carbon and optionally further metals and metallic carbides and nitrides and/or solid nitrogen compounds as suppliers of carbon and/or nitrogen, each exclusively in powder form, are compacted to form a shaped body and then, either at a pressure of Pa or preferably without pressure, are subjected to reaction sintering, in particular reaction sintering which is carried out at least intermittently in a microwave field of between 0.01 and 10 W/cm energy density.
Abstract:
The invention concerns a method and device for the heat treatment of hard metals, cermets and/or ceramics in a microwave sintering furnace, the material to be treated being moved together with the resonator relative to one or a plurality of microwave sources (13). The material to be treated (14) is disposed in individual cassettes (10) which, with the exception of an opening necessary for the microwave radiation, consist of material which is impermeable to microwaves and simultaneously form the resonance chamber whose length, height and/or depth in the uncharged state are too small to generate a continuous energy distribution at the microwave frequency used but, in the charged state, permit homogeneous heating. Preferably the length, height and/or depth of the chamber do not exceed sixth wavelengths of the microwave radiation used.
Abstract:
A stationary wave is generated in an antenna cavity (53) in a microwave furnace designed for sintering nuclear fuel. Microwaves are extracted from said stationary wave by means of slits (54) in a resonator cavity (51) containing the nuclear fuel. The position of the slits is adjusted in such a way that a predefined temperature profile is generated in the nuclear fuel.
Abstract:
This invention relates to a method for the thermal treatment of granular solids in a reactor (1) with swirl chamber (4), which in particular constitutes an flash reactor or suspension reactor, wherein the microwave radiation from a microwave source (2) is fed into the reactor (1) through a wave guide, and to a corresponding plant. To avoid deposits in the wave guide, the same constitutes a gas supply tube (3), a gas stream being additionally fed through the gas supply tube (3) into the swirl chamber (4).
Abstract:
This invention relates to a method for the thermal treatment of granular solids in a fluidized bed (3, 3a) which is located in a fluidized-bed reactor (1, 1a, 38), wherein microwave radiation is fed into the fluidized-bed reactor (1, 1a, 38) through at least one wave guide (5, 46), and to a corresponding plant. To avoid depositions in the wave guide (5, 46), a gas stream is fed into the fluidized-bed reactor (1, 1a, 38) through the same wave guide (5, 46).
Abstract:
This invention relates to a method for the thermal treatment of granular solids in a fluidized bed (3, 3a) which is located in a fluidized-bed reactor (1, 1a), wherein microwave radiation is fed into the fluidized-bed reactor (1, 1a) through at least one wave guide (5), and to a corresponding plant. To improve the efficiency of the microwave irradiation, the irradiation angle of the microwaves is inclined by an angle of 10° to 50°, in particular 10° to 20°, with respect to the principal axis (11) of the fluidized-bed reactor (1, 1 a).
Abstract:
Process for producing fluorinated olefins from fluorinated materials, the process comprising thermally decomposing the fluoropolymers into fluoroolefins in a reactor having a feeding zone where the fluorinated materials are fed into the reactor and a decomposition zone where the fluorinated materials are thermally decomposed and wherein the thermal decomposition is carried out in the presence of microwave irradiation.
Abstract:
Process for producing fluorinated olefins from fluorinated materials, the process comprising thermally decomposing the fluoropolymers into fluoroolefins in a reactor having a feeding zone where the fluorinated materials are fed into the reactor and a decomposition zone where the fluorinated materials are thermally decomposed and wherein the thermal decomposition is carried out in the presence of microwave irradiation.