Abstract: Heating a printing substance and/or toner, in an electrophotographic printer, with a standing microwave formed by at least one cavity resonator, with the printed matter being caused to move through the resonator gap. The power distribution of the microwave applied by the resonator is shaped and configured for specific application requirements.

Abstract: A microwave applicator for heating loads being a waveguide transition between the rectangular TE10 and TE20 modes comprising a TE10 mode section and a TE20 mode section. The location of the load being inside said TE20 mode section and with its major axis perpendicularly to the major propagation direction of the TE20 mode, close to a shorting wall of said TE20 mode section and also close to the centreline of said propagation direction.

Abstract: Microwave heating apparatus comprising an elongated dielectric microwave applicator with an axial TM type mode, said dielectric applicator is provided with a load chamber for a load to be heated, said load chamber is located in a centered axial position inside the applicator. Two microwave feeding points are arranged at a lower end of the applicator for feeding microwave energy in the axial direction of the applicator so that significant cross-talk between the applied microwaves is avoided.

Abstract: In order to reduce reflected waves and improve heating matching, a microwave heating apparatus is equipped with at least one cone-shaped, bell-shaped, pyramid-shaped or similarly shaped waveguide, a reflector apparatus provided inside the waveguide, and a reflection diffusion apparatus provided inside the oven.

Abstract: A microwave oven and a method for heating a load which is placed therein. According to the invention a predetermined mode in the cavity of a microwave oven is fed by means of an associated feeding port which is arranged to feed essentially the intended mode only, the feeding of a mode other than the intended, predetermined mode being essentially prevented.

Abstract: A temperature control apparatus for an exhaust gas sensor can promptly heat the exhaust gas sensor with an electric heater up to an activation temperature while preventing thermal shock damage thereof due to water immediately after engine starting. Energization of an electric heater arranged near an exhaust gas sensor is controlled by a CPU cooperating with a ROM through a switching element. A low voltage is supplied for evaporation of the water by a first preheater immediately after engine starting, and enhanced preheating is subsequently carried out by a second preheater for preventing thermal shock on the exhaust gas sensor. Thereafter, a heating controller performs automatic control with a proper activation temperature of the exhaust gas sensor being made as a target. The temperature controlled by the first preheater is set to such a temperature level at which rapid cooling damage of the exhaust gas sensor due to the water will not be caused but the water can be evaporated.

Abstract: Distributed high power solid state microwave sources are provided to improve the efficiency of microwave heating applications. A plurality of solid state microwave sources can be distributed throughout and/or adjacent to a microwave environment with the microwave power output of the solid state microwave sources being directed toward the chamber. The distribution of the plurality of solid state microwave devices can be customized to the specific size and shape of the microwave chamber and/or specific regions/compartments of the microwave chambers.

Abstract: A distributed microwave system comprising a single microwave source that can be used to supply one or more microwave-using devices. The microwave source is located remotely from the microwave-using devices and connected thereto by a microwave conduit.

Abstract: An elliptical exposure chamber has an extended focal region. A plurality of cylindrical reactors (25) form the extended focal region. Reducing the size of the opening (58) to each reactor (25) reduces the amount of energy reflected and increases the overall heating. In order to efficiently deliver the electromagnetic energy to the reduced opening (58), a tapered waveguide (55) has a concave end (56). A power splitter (42) divides power from a central waveguide (52) to the plurality of reactors (25). The power that is delivered to each reactor (25) can be adjusted by adjusting the impedance of each reactor (25), the width of each reactor (25) or the width of the opening (58) to each reactor (25). The width of the opening (58) to each reactor (25) can be controlled by a movable metal plate (44). A dielectric wheel can be used to shift hot spots along the focal region.

Abstract: The present invention relates to an apparatus and methods for performing chemical reactions. In particular, the present invention relates to an apparatus for heating chemical reaction mixtures. The apparatus applies one or more semiconductor based microwave generators making the apparatus suitable for parallel processing of chemical reaction mixtures. The invention further relates to methods for performing chemical reactions, e.g. methods for heating a plurality of samples simultaneously or sequentially, methods for monitoring a microwave heated chemical reaction, and methods where the optimum conditions with respect to parameters, such frequency and applied power can be determined for the system consisting of apparatus plus sample.

Abstract: In order to reduce reflected waves and improve heating matching, a microwave heating apparatus is equipped with at least one cone-shaped, bell-shaped, pyramid-shaped or similarly shaped waveguide, a reflector apparatus provided inside the waveguide, and a reflection diffusion apparatus provided inside the oven.

Abstract: A microwave delivery system for a cooking appliance includes an electronic control unit and a plurality of magnetrons arranged in a spaced relationship for the introduction of various energy fields into an oven cavity. The electronic control unit creates a phase angle shift between each of the microwave energy fields such that a constructive standing wave propagates about the oven cavity. In this manner, localized hot and cold spots, which can detrimentally affect cooking efficiency, are eliminated without the need for mode stirring or turntables. With this system, the total energy delivered to the oven cavity is the combined energy level of the various microwave energy fields.

Abstract: An instrument for microwave-assisted chemical processes is disclosed that provides greater flexibility in carrying out microwave-assisted chemistry under varying conditions. The instrument includes a source of microwave radiation, and a cavity in communication with the source, with the cavity including at least one wall formed of two engaged portions that form a barrier to the transmission of microwaves when so engaged. The engaged portions are disengagable from one another, and one of the portions includes a microwave-attenuating opening.

Abstract: On a home page of a home page storing unit (421) of a host computer (4), information related to a plurality of recipes and recipe data (MI) corresponding to each of the plurality of recipes are included. The recipe data includes a heating control code (DS141) common among different types of microwave ovens (1) for heating and cooking the corresponding recipe. The microwave oven has a memory (11A) that stores a plurality of different pieces of procedure information (heating sequence FLi, heating mode data MDi, heater down time data HDT) indicating procedure matching the type, for executing a heating operation. The microwave oven performs the heating operation in accordance with one or more pieces of procedure information read from the memory (11A) based on the heating control code.

Abstract: The present invention relates to an apparatus and methods for performing chemical reactions. In particular, the present invention relates to an apparatus for heating chemical reaction mixtures. The apparatus applies one or more semiconductor based microwave generators making the apparatus suitable for parallel processing of chemical reaction mixtures. The invention further relates to methods for performing chemical reactions, e.g. methods for heating a plurality of samples simultaneously or sequentially, methods for monitoring a microwave heated chemical reaction, and methods where the optimum conditions with respect to parameters, such frequency and applied power can be determined for the system consisting of apparatus plus sample.

Abstract: Method and device for moisture profiling of fibrous material web to be dried in machines for manufacturing and/or refining of fibrous material web. Method includes subjecting fibrous material web to electromagnetic waves in the form of high-frequency waves. Device includes a fibrous material web support that supports travel of fibrous material web and a rotating cylinder. Rotating cylinder receives fibrous material web from fibrous material web support, and fibrous material web support is arranged outside fibrous material web in relation to the surface of the rotating cylinder. At least one electromagnetic wave transmitter is also included.

Abstract: A microwave heating apparatus including a cavity for heating food, a first antenna, which projects into the cavity and is arranged to pass into or through the food in order to irradiate the food internally, and a second antenna arranged to supply microwave radiation into the cavity in order to irradiate the food externally. Microwave energy is supplied to the first and second antennae in such a way that the user can independently control the levels of microwave energy irradiated by the first and second antennae.

Abstract: An instrument for microwave-assisted chemical processes is disclosed that provides greater flexibility in carrying out microwave-assisted chemistry under varying conditions. The instrument includes a source of microwave radiation, and a cavity in communication with the source, with the cavity including at least one wall formed of two engaged portions that form a barrier to the transmission of microwaves when so engaged. The engaged portions are disengagable from one another, and one of the portions includes a microwave-attenuating opening.

Abstract: A method and device for moisture profiling of a fibrous material web to be dried in machines for manufacturing and/or refining this web that includes subjecting the fibrous material web to electromagnetic waves in the form of microwaves and/or high-frequency waves.

Abstract: The present invention relates to an apparatus and methods for performing chemical reactions. In particular, the present invention relates to an apparatus for heating chemical reaction mixtures. The apparatus applies one or more semiconductor based microwave generators making the apparatus suitable for parallel processing of chemical reaction mixtures. The invention further relates to methods for performing chemical reactions, e.g. methods for heating a plurality of samples simultaneously or sequentially, methods for monitoring a microwave heated chemical reaction, and methods where the optimum conditions with respect to parameters, such frequency and applied power can be determined for the system consisting of apparatus plus sample.

Abstract: A microwave heating system is disclosed for enhancing physical and chemical processes. The system includes a microwave source, an antenna having a cable, a receiver for receiving microwaves generated by the source, with the receiver being connected to a first end of the cable, and a transmitter for transmitting microwaves generated by the source, and with the transmitter being connected to an opposite end of the cable. The system also includes a reaction vessel with the transmitter inside the reaction vessel; and a microwave shield surrounding the transmitter for preventing microwaves emitted from the transmitter from extending substantially beyond the reaction vessel.

Abstract: A feed that provides circularly polarized microwave energy such as for energizing a microwave oven cavity. The feed includes a transformer to match a linearly polarized rectangular waveguide to a polarization waveguide section which may be circular or square in cross section. The polarization waveguide section contains an asymmetrical element that provides symmetry about a plane only. The asymmetrical element therefore introduces a difference in microwave electrical phase for polarizations which are respectively parallel to and perpendicular to the symmetry plane. A second waveguide section having a bend is also used in the feed assembly. The second waveguide section, which may for example be a bent section of circular waveguide, also presents an electromagnetic symmetry about a plane only. As a result, the two waveguide sections operating together provide circularly polarized energy at constant magnitude but continually rotating phase.

Abstract: A microwave heating system is disclosed for enhancing physical and chemical processes. The system includes a microwave source, an antenna having a cable, a receiver for receiving microwaves generated by the source, with the receiver being connected to a first end of the cable, and a transmitter for transmitting microwaves generated by the source, and with the transmitter being connected to an opposite end of the cable. The system also includes a reaction vessel with the transmitter inside the reaction vessel; and a microwave shield surrounding the transmitter for preventing microwaves emitted from the transmitter from extending substantially beyond the reaction vessel.

Abstract: Actuators that generate positional change and external force in response to remote microwave radiation. In a preferred embodiment the actuators remotely release an electrical connector by the heating of a friable metal element; and to the method of using microwave actuators for efficient disassembly of a manufactured hard goods entity.

Abstract: A microwave vessel system for external and noninvasive pressure monitoring and control is disclosed. The system comprises a reaction vessel formed of a material that is transparent to microwave radiation, with the reaction vessel including a portion that is movable under pressure generated by a chemical reaction inside the vessel while maintaining the reaction sealed inside the vessel. A sensor is adjacent to the movable portion of the vessel for detecting the motion of the movable portion as the portion responds to pressure generated inside the vessel. The system includes means for maintaining the sensor against the movable portion while microwaves are applied to the vessel so that the movement of the movable portion under pressure is detected by the sensor.

Abstract: Timber drying apparatus comprises a housing defining a microwave cavity (4) for containing a quantity of timber, a microwave generator (1) coupled to the housing for introducing microwave energy into the cavity, temperature sensing means (13) arranged to sense the temperature of timber within the cavity and/or weight sensing means (8) for sensing the weight of timber within the cavity and control means for varying the power output of the microwave generator in response to the sense temperature and/or weight. The humidity and/or air temperature may also be sensed in the cavity. The timber may be oscillated within the cavity.

Abstract: An apparatus for generating uniform heating in material contained in a cylindrical vessel is described. TE.sub.10 -mode microwave radiation is coupled into a cylindrical microwave transition such that microwave radiation having TE.sub.11 -, TE.sub.01 - and TM.sub.01 -cylindrical modes is excited therein. By adjusting the intensities of these modes, substantially uniform heating of materials contained in a cylindrical drum which is coupled to the microwave transition through a rotatable choke can be achieved. The use of a poor microwave absorbing insulating cylindrical insert, such as aluminum oxide, for separating the material in the container from the container walls and for providing a volume through which air is circulated is expected to maintain the container walls at room temperature. The use of layer of highly microwave absorbing material, such as SiC, inside of the insulating insert and facing the material to be heated is calculated to improve the heating pattern of the present apparatus.

Abstract: A process for joining ceramic parts comprises autoclaving a powdered ceramic composition to increase its hydrogen form contents to a concentration that serves to increase the composition's absorption of microwave energy during subsequent heating of the ceramic parts; coating the autoclaved ceramic composition on the surfaces of the parts to be joined together; and placing the coated surfaces of the parts to be joined together and focusing microwave energy at the joint between the parts in order to seal the joint by refiring and rereacting the parts, the microwave energy being of sufficient power and being uniformly applied to the joint for a sufficient period of time to seal the joint.

Abstract: A microwave oven excitation system comprising a cylindrical microwave launcher for radiating microwave energy into a heating cavity of a microwave oven which is mounted adjacent to the heating cavity, a quarter-wave matching waveguide secured to the launcher, a rectangular waveguide secured to the quarter-wave matching waveguide, and a source of microwave energy at a predetermined operating frequency secured to the rectangular waveguide remotely from the launcher. In addition, a mode stirrer may be optionally installed within the cylindrical microwave launcher. Also, an iris may be optionally mounted between the cylindrical microwave launcher and the heating cavity.

Abstract: A microwave oven excitation system comprising a cylindrical microwave launcher for radiating microwave energy into a heating cavity of a microwave oven which is mounted adjacent to the heating cavity in either a substantially vertical position or a substantially horizontal position, a first hollow waveguide secured to the launcher, a first source of microwave energy at a predetermined operating frequency secured to the first waveguide, a second hollow waveguide secured to the launcher substantially perpendicular to the first waveguide, and a second source of microwave energy at a predetermined operating frequency secured to the second waveguide. Alternatively, a single waveguide is secured to the cylindrical launcher and has only a single source of microwave energy secured thereto. In either case, a mode stirrer can be installed within the cylindrical microwave launcher.

Abstract: An apparatus, system, and method, for using circular mode magnetic microwave energy to heat the interior regions of a work piece of wood fiber and glue. The microwaves are generated and transmitted as rectangular waveguide mode microwave energy, and are converted by mode converter to circular magnetic mode microwave energy. As circular magnetic mode microwave energy, the microwave energy passes through a work piece or billet of material is reflected on the other side, and travels through the billet a second time. Reflected microwave energy from the main reflected wave as well as reflections from other structures, surfaces and layers in the system travel back toward the microwave source. They are sensed, and a computer tuning system causes capacitive probes to generate offsetting microwave reflections, which are opposite in phase and equal in magnitude to the sum of all of the reflected waves.

Abstract: A method and apparatus for liquid thermoset resin or polymer molding using electromagnetic waves (particularly radiofrequency waves or microwaves), is described. The method and apparatus uses a metal mold (10, 212) with a cavity (401) for the molding as well as for confinement of the electromagnetic waves. Multiple low loss ports (A, B, C, D, E, p1, p2, p3) are provided for introducing the microwaves into the cavity.

Abstract: An assembly for applying microwave irradiation to a load having a generally circular cross-section. The applicator supports a dominant TM.sub.120 mode and the load is aligned with a central axis in the applicator, with each aperture of a pair of feed apertures diametrically opposed (for the circular cross sectional case) or located on parallel opposed walls (for the polygonal cross sectional case) with one of the pair of feed apertures positioned at 90 degrees with respect to the other pair about the axis. The applicator may be formed as a cylinder or as a polygonal prism of the type having parallel opposed sides, such as those having a square, hexagonal or octagonal cross-section. Means such as a microwave transparent tube or conveyor provide for positioning of the load in the applicator. In an alternative embodiment, two cavities are used, with one cavity associated with each of the two feed systems, and a means for conveying the load from the first cavity to the second cavity is provided.

Abstract: The present invention provides a new and useful method for bringing about a metallurgical effect in a metal-containing ore or concentrate comprising treating said ore in a resonant microwave cavity while maximizing electric field strength in the area of said ore in said cavity.

Abstract: Disclosed is a wave guide system of a microwave oven which has a partition wall for separating a cavity in which food to be cooked is placed from a control room in which a magnetron for generating microwaves is provided, the partition wall having a first and second microwave feed openings for feeding the microwaves to the food; and a wave guide provided to the partition wall where the first and second microwave feed openings are formed, the wave guide having a horizontal upper wall, a side wall to which the magnetron is attached, and a lower wall having a first inclined portion connected to the side wall, a second inclined portion connected to the partition wall, and a vertical portion provided between the first and the second inclined portion.

Abstract: A microwave processing system is disclosed. The system is particularly useful for concurrently controlling a plurality of chemical reactions from a single microwave source. The system comprises a source that produces electromagnetic radiation in the microwave range; a waveguide in communication with the source and into which the source propagates microwave radiation; a resonator in communication with the waveguide; and an adjustable dynamic moderating device between the waveguide and the resonator for moderating the wave energy passing from the waveguide to the resonator without substantially changing the propagated mode in the waveguide.

Abstract: An apparatus, system, and method, for using circular mode magnetic microwave energy to heat the interior regions of a work piece of wood fiber and glue. The microwaves are generated and transmitted as rectangular waveguide mode microwave energy, and are converted by mode converter to circular magnetic mode microwave energy. As circular magnetic mode microwave energy, the microwave energy passes through a work piece or billet of material is reflected on the other side, and travels through the billet a second time. Reflected microwave energy from the main reflected wave as well as reflections from other structures, surfaces and layers in the system travel back toward the microwave source. They are sensed, and a computer tuning system causes capacitive probes to generate offsetting microwave reflections, which are opposite in phase and equal in magnitude to the sum of all of the reflected waves.

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: A microwave applicator including a generally cylindrical microwave containment chamber, a microwave energy source, and a feed structure connecting the microwave energy source to the containment chamber. The diameter of the containment chamber is designed according to a process that need only take into account supporting a microwave pattern having substantially only two transverse magnetic modes, each with a characteristic guide wavelength, where the guide wavelength of one mode is substantially equal to twice the guide wavelength of the other mode. Additionally, the interior diameter can be sized to minimize the index subscript numbers of the transverse magnetic modes. The feed structure of the applicator includes at least two feed apertures spaced physically apart around the cylindrical axis of the applicator by a physical angle equal to an electrical phase shift angle of the microwaves introduced through the respective apertures, which in a preferred embodiment is 90 degrees.

Abstract: A wave guide system of a microwave oven is provided, comprising a cavity containing a food to be cooked and having a pair of microwave feed openings formed in one wall thereof; a magnetron having an antenna and positioned between the microwave feed openings in spaced apart relation to the wall having the feed openings, to generate microwaves having a wavelength of .lambda..sub.g ; and a waveguide provided to cover the feed openings, support thereon the magnetron and guide the microwave through the feed openings into the cavity and having a short circuited surface which is spaced apart from the antenna by a distance of .lambda..sub.g /4 and parallel to the antenna. With this arrangement, the microwave generated in the magnetron produce standing waves in the waveguide, and then are emitted into the cavity through the microwave feed openings of the cavity, thereby uniformly heating a food in the cavity.

Abstract: A microwave applicator device for continuous heat treatment of elongate products comprises an applicator housing that defines a generally rectangular waveguide cavity and at least one excitation system for exciting the cavity with microwaves propagating in TE.sub.01 transverse electric mode, the system including at least one microwave generator associated with a feed waveguide connected to the cavity via a window formed through a wall of the cavity. The front and rear walls of the feed waveguide are respectively connected to the front and rear edges of the window, and the feed waveguide is associated with a guide flap extending in the cavity in the vicinity of the rear edge of the window, and with a guide member provided substantially facing the window.

Abstract: A microwave processing system is provided wherein the material to be processed is in the form of a web type quantity configuration with a thickness that is small in relation to the wavelength of a particular microwave frequency. The material is passed through the field associated with a plurality of microwave standing waves of the particular frequency, each adjacent standing wave being offset 1/4 wavelength along the direction of movement of the web. A carrier gas removes volatile solvents from the material surfaces. Control is provided for the interrelationship of temperature, rate of movement, flow of carrier gas, and microwave power.

Abstract: A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34) for testing or other selected applications. The variable frequency heating apparatus (10) is used in the method of the present invention to monitor the resonant processing frequency within the furnace cavity (34) depending upon the material, including the state thereof, from which the workpiece (36) is fabricated. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a microwave voltage-controlled oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34).