Abstract: A method of preparing a food product is disclosed and includes the steps of placing the food product within a cooking cavity, reducing the pressure within the cooking cavity thereby creating a vacuum within the cooking cavity, heating the food product within the cooking cavity and returning the cooking cavity to atmospheric pressure. In doing so, a temperature necessary to cook the food product in the vacuum is less than that temperature necessary to cook the food product at atmospheric pressure. Consequently, the food product may be fully cooked at a temperature which does not cause the food product to dry-out or become tough.

Abstract: A plant for pasteurizing or sterilising solid or liquid food products subjects the previously packaged products to heat treatment using microwaves in a pressurized chamber, in order to guarantee its conservation for long periods of time. At least three phases of operation include a rapid heating phase of the products, up to a temperature which is slightly lower than the pasteurizing or sterilising temperature; and a temperature equalising phase, and a cooling phase. The pressure inside the pressurised chamber, during the phases varies as a function of the temperature reached by the products. The plant includes a number of tubular elements (2, 3, 4; 11, 12, 13, 14), each of which consists of a number of sections (2a, 3a, 4a; 11a, 12a, 13a, 14a) cylindrical in shape and of a small diameter, each tubular element having devices for inserting and removing from it the products to be treated and for varying the ambient pressure inside it, as function of the temperature reached by the products.

Abstract: There is provided a microwave waste sterilizer comprising an upper outer shell, a lower outer shell, an upper means for guiding microwave energy, a lower means for guiding microwave energy, an upper means for dispersing microwave energy, and a lower means for dispersing microwave energy. There is also provided a method for sterilizing waste materials with dual sources of microwave energy. Further there is provided a method for dispersing microwave energy into a chamber such that the dispersed microwave energy creates a flux field of substantially uniform flux.

Abstract: The present invention concerns a device for measuring the pressure and temperature in at least one pressure-tight analysis vessel, that has been sealed by means of a lid, whereby heat is supplied to the analysis vessel by means of a microwave oven. The device comprises a measurement device that is connected to a unit for controlling the microwave oven. In this regard, the measurement device is arranged in a microwave-tight housing inside the microwave field that is produced by the microwave oven. The housing is constructed in such a way that it forms a shield that is impermeable for the microwave field. A microwave-free zone is produced inside the housing. Electronic, current-carrying components can be arranged in the microwave-tight housing without, as a result, generating interference in the microwave field.

Abstract: In a fluidized bed reactor for preparing a metal nitride by feeding metal powder and a non-oxidizing gas containing N.sub.2 or NH.sub.3 into a reaction tube (1) to form a fluidized bed (2) therein and heating the fluidized bed for nitriding the metal powder, an envelope (11) encloses the reaction tube (1) for preventing the surrounding air from entering the reaction tube. A heater (9) is disposed outside the envelope (11) for heating the fluidized bed (2) to 1,200.degree. C. or higher. The envelope prevents penetration of the surrounding air into the reaction tube and also prevents deterioration of the heater and surrounding components by scattering of metal fines. The reactor ensures safe operation to prepare metal nitride powder of high purity on an industrial scale.

Abstract: A two-zone lime mud calciner is provided for processing lime mud from kraft pulp recovery operations. A conveyer is employed for conveying lime mud horizontally through the calciner. The first zone and second zone of the calciner each contains a dielectric hysteresis heating device for first drying the lime mud in the first zone and then decomposing the dried lime mud to lime and carbon dioxide. A co-current flow of purge air removes steam generated in the first zone and a counter-current flow of purge air removes carbon dioxide generated in the second zone with a vent being provided adjacent the upstream and of the second zone.

Abstract: An oven with a humidity conditioner is capable of cooking food by appropriately humidifying or dehumidifying it while the amount of steam contained in an oven cavity is being regulated. The oven includes a heater or magnetron for heating the food accommodated in the oven cavity, a humidity regulator for regulating the humidity inside the oven cavity, a cooking method selector for selecting a cooking method, and a controller for controlling the humidity regulator in response to a signal from the cooking method selector to selectively humidify and dehumidify the interior of the oven cavity.

Abstract: To reliably sterilize hospital refuse in a quantities and configuration in which it occurs on its collection, the plant includes a refuse loading device, a shredder, a motorized screw for refuse conveying, a microwave oven and a device for removing the treated refuse upon its exit from the oven.

Abstract: A new microwave autoclave apparatus, and a method for pasteurizing, sterilizing or retorting food product in a continuous mode, and in commercial quantities, using microwave radiant energy. In this new microwave autoclave apparatus, containers of food-stuff are held tightly within individual moving bottom vessel, and a corresponding moving top cover. The moulds therefrom, made of a material which is permeable to microwave radiation, are linked together to form a chain such that a continuous flow of container enters and leaves a microwave chamber. The synchronization of the moving top covers with the moving bottom vessels, and the opposing forces applied thereupon provide tightly fitted cavities capable of supporting substantial pressure, and thus providing a retort effect. The moulds prevent undesired expansion of containers during heating periods, without applying adverse pressure beyond its original shape during the cooling phase.

Abstract: Method and apparatus for sterilizing articles including introducing the article and liquid solution into a collapsible pouch formed of vapor-impermeable sheet material, sealing the collapsible pouch to form a gas-tight assembly, and heating the gas-tight assembly to vaporize the liquid solution to produce an atmosphere of hot vapor. The liquid is introduced into the pouch in a quantity sufficient to create an overpressure when vaporized which is indicated by the collapsible pouch expanding to a distended condition. In one embodiment, the liquid solution is vaporized by irradiating the gas-tight assembly with microwave radiation. In other embodiments particularly suited for sterilizing a plurality of metallic articles, the at least one article is surrounded by shielding, which may be separate from or integrated with the pouch, which presents a barrier to the transmission of microwave radiation.

Abstract: A container for use in a microwave apparatus, in particular for heating, drying, disinfecting and/or sterilizing of materials, objects, liquids or the like, includes a lid securely attachable via a pressure lock to the container and including connections for allowing attachment of various valves, pumps etc. to monitor and influence conditions in the container. The connections are self-sealing plug connector pipes which are engageable with a complementary coupler piece of the microwave apparatus. The microwave apparatus includes an injector unit by which water or other liquid is introduced into the material to be treated, with the amount of injected water being dependent on the water content of the material. The injector unit includes a nozzle head which projects into the treatment chamber of the microwave apparatus and incorporates sensors for determining physical and/or chemical parameters.

Abstract: Apparatus for heating and thermal decontaminating, e.g. sterilizing, pasteurizing and/or disinfecting, pumpable or pourable material, includes a microwave unit forming a treatment chamber for receiving the material transported along a passageway and for subjecting the material to microwave radiation. Two pumps are respectively situated upstream and downstream of the treatment chamber, with a pressure sensor being arranged between the pumps for generating a a signal commensurate with the pressure in the passageway between the pumps. The signal is transmitted from the pressure sensor to a control unit which is operatively connected to both pumps.

Abstract: An improved reactor for a high-temperature deposition reaction on seed particles is constructed with a fluidized bed which is divided into a heating zone and a reaction zone by a partition. Seed particles in the heating zone are fluidized by a carrier gas and are heated by microwaves. On the other hand, the reaction zone for the deposition reaction, through which reaction gases pass, is heated by particle mixing between the reaction zone and the upper section of the heating zone. Subsequently, a desired reaction temperature at the reaction zone is maintained stable without deteriorating the microwave heating of the heating zone.

Abstract: An improved method is provided for the deposition of high-purity silicon on silicon particles from silicon source gases in a fluidized bed reactor which is divided into a heating zone and a reaction zone by a partition. Silicon particles in the heating zone are fluidized by a carrier gas such as hydrogen and are heated by microwaves. On the other hand, the reaction zone for the deposition of silicon, through which reaction gases including the silicon source pass, is heated by particle mixing between the reaction zone and the upper section of the heating zone. Subsequently, a desired reaction temperature at the reaction zone is maintained stable without deteriorating the microwave heating of the heating zone.

Abstract: A ventable container for materials to be heated (preferably digested) by microwave radiation includes a movable rupture diaphragm in a venting passageway in a closure or cover for such container. Such diaphragm is tightenable into place so that the container is sealed and in such sealed state is protected by the rupture diaphragm against pressures that could develop in the container that are higher than that for which it was designed. An important feature of the invention is that the rupture diaphragm is controllably movable, when desired, to open positions to vent the container during heating and afterward, and is resealable after venting. Because of the chemical reactivity of the reagents utilized in digestions an inner chemically resistant liner is desirably employed in conjunction with a physically stronger outer body, with the outer body giving the liner enough strength to withstand pressures developed during the heating.

Abstract: A heat treatment installation for parts made of a composite material having a ceramic matrix and including a treatment enclosure which is connected to a microwave generator by a waveguide and which includes a press for hot pressing a part to be treated in the enclosure and a gas source for introducing a protective gas into the enclosure.

Abstract: A swirl flow microwave plasma torch is provided for the growth of diamond films. The swirl flow torch incorporates an injection nozzle that directs reactant gases into a cylindrical flow tube extending through the center of a tuned microwave cavity. The outer surface of the nozzle comprises a contoured, conical shape that causes inert gas, directed tangentially against the outer surface of the nozzle, to swift in a helical path that surrounds and confines the reactant gas emerging from the nozzle. The tuned cavity is coupled to a microwave energy source to generate a highly localized plasma in the reactant gas in the center of the sheathing swirl of inert gas. The swirl of inert gas contains the plasma in a well-defined shape, prevents in-diffusion of undesirable gases, forms a boundary layer to prevent plasma migration, and provides flow tube cooling. The reactant gas flow forces the plasma out of the flow tube to form a plasma flame that can be impinged on a substrate to induce diamond growth.

Abstract: A device for heating substances under the development of high pressures in a microwave field is disclosed. Those parts of the device lying in the microwave field comprise material transparent to microwaves. The device comprises a pressure-resistant cylindrically shaped outer container and a cylindrically shaped inner container disposed inside the outer container. Both the inner and outer container is provided with a cover or a cap for closure thereof. An interspace is provided between an inner jacket surface of the outer container and an outer jacket surface of the inner container, which space is connected with a space outside the device via connecting channels. The interspace preferably contains a cooling media which is transported to and from the interspace and outer space via the connecting channels.

Abstract: A method and apparatus are provided for the rapid heat treatment of products, and especially gas-permeable, water-containing products such as bread dough. Baking of dough involves placing the dough within an enclosed oven or zone (1) and subjecting the dough to dielectric (e.g. radio-frequency or microwave) heating using appropriate generators (6, 7, 7a, 8a). Radiant heat from an appropriate source (9) and hot oven gases are simultaneously applied for crust formation. During at least a portion of the baking cycle, the gas pressure within the zone (1) is selectively elevated by steam addition (10) in response to the rise in gas pressure within the dough resulting from vaporization of water therein. In this way, the pressure differential between the dough interior and the ambient environment is minimized, and the dough may be rapidly baked without fear of significant dough disruption. Cooling is effected by gradually reducing the zone pressure, through use of a vacuum pump (12).

Abstract: A process for rapidly sterilizing biological media, such as broths and gels used as incubation or growth media to test the presence of microorganisms, such as bacteria, includes applying microwave radiation to such an aqueous biological medium contained in a microwave transmissive pressure retaining container, such as a capped cylinder made of polytetrafluoroethylene, which cap is preferably equipped with ports, by directing the microwave radiation through the container and onto the medium in such amount that the pressure in the container and the temperature of the medium are raised above ambient pressure and temperature, and maintaining such raised pressure and temperature for a time sufficient to sterilize the medium.

Abstract: A baking apparatus and a method for quickly providing freshly baked bread by reducing time required for baking. In bread-making operations, reducing baking time by using a dough-surface heating unit together with an dough-interior heating unit and then subjecting the baked bread to reduced pressure for lowering moisture content at the dough interior.