Abstract: The invention described herein generally pertains to coupling microwave energy into a tuned multi-section WR-975 waveguide assembly, connected to a waveguide containing a ceramic cylindrical applicator, terminated in a dummy load, for pre-heating fuels to improve vaporization, combustion efficiency, and soot reduction in combustion chamber(s). Designed primarily for processing liquid byproducts produced during biodiesel fuel manufacturing, this invention establishes a charge density in a cross-coupled applicator, according to the applicator's volume, dielectric characteristics of the materials being processed, applied frequency, and voltage. This invention may also be used for preheating or polarization of solids within a pipe-conveyed slurry, such as biosolids, bituminous coal, crude oil sludge, paper pulp or shale oil rock.

Abstract: A microwave heating device and a method for heating a load using microwaves are provided. The microwave heating device comprises a cavity adapted to receive a load and at least two microwave sources for feeding microwave energy into the cavity through at least two feeding ports respectively. The microwave heating device further comprises at least two field sensors adapted to measure field strengths of the microwave energy in the cavity. A first field sensor is arranged at a first location for measuring the field strength representative of a mode fed from a first feeding port and a second field sensor is arranged at a second location for measuring the field strength representative of a mode fed from a second feeding port. The microwave heating device further comprises a control unit connected to the microwave sources and the field sensors for regulating the microwave sources based on the measured field strengths.

Abstract: The invention relates to a temperature probe for an oven, comprising in one embodiment a longitudinal housing in the form of a spit. A temperature sensor and an electronic unit are arranged in a tip and are connected at the other end to emitting means. The temperature probe comprises a thermogenerator for producing energy. The thermogenerator uses a temperature difference between a higher temperature inside the oven and a lower core temperature in a food product, such as roast, in which the temperature probe is inserted, for producing energy for operating the emitting means.

Abstract: Methods and apparatus for drying ceramic green bodies include providing one or more ceramic green bodies in a microwave heating chamber operatively connected to a microwave source and a PLC. The total mass of the ceramic green bodies present in the microwave heating chamber is determined. Microwave energy is generated with the microwave source and transmitted from the microwave source to the microwave heating chamber. A transmitted power of the microwave energy transmitted from the microwave source to the microwave heating chamber is measured with power sensors. The reflected power of reflected microwave energy reflected back from the microwave heating chamber is also measured. The power of the microwave energy transmitted from the microwave source to the microwave heating chamber is adjusted based on the total mass of ceramic green bodies present in the microwave heating chamber, the measured transmitted power and the measured reflected power.

Abstract: The present invention describes a bolometric device with receiving cavity for measuring a beam of high frequency microwaves, comprising a hollow body (1) with receiving cavity (50) having an opening (2) for the entrance of said beam of high frequency microwaves in said receiving cavity (50), a diverging mirror (3) located in the lower part of said cavity (50) for reflecting said beam of microwaves on an absorbent coating material (4) applied on the internal surface (5) of the hollow body (1), a cooling circuit (7) for transferring the thermal energy accumulated on the absorbent coating material (4) and a circuit (6) for measuring the power of the beam of high frequency microwaves entering the hollow body (1). Said absorbent coating material (4) consists of boron carbide. In addition a procedure is described for coating with an absorbent material the internal surface (5) of a hollow body (1) being part of the aforementioned device for measuring a beam of high frequency microwaves (FIG. 1).

Abstract: A method and apparatus for adaptively maintaining the power-frequency spectrum in a reverberation chamber. The invention is thus capable of maintaining a relatively constant power-frequency spectrum in the chamber even when a device under examination is placed into the chamber which exhibits selective frequency absorption and or directional frequency absorption. The object disposed within the chamber need not necessarily be a device under examination. Rather, the present invention can also adaptively maintain a relatively constant power-frequency spectrum when heating any material disposed within a electromagnetic wave chamber.

Abstract: A household appliance (1) e.g a washer-dryer, comprises an enclosure (2) into which objects to be heated are placed, a magnetron (4) for generating microwaves, a waveguide (3) for feeding the generated microwave into the enclosure, an arc detector (5) coupled to the waveguide (3) for detecting the arcing within the enclosure (2) and a control unit (6).

Abstract: A microtiter plate system includes an integral heater. In an embodiment, the integral heater includes a heater plate. In another embodiment, the integral heater includes resistive heater wires positioned beneath and/or between the wells of a microtiter plate. In an embodiment, the microtiter plate system includes optically clear well bottoms that permit sensing and measurement of samples through the optically clear well bottoms. In an implementation, an optically clear heater is positioned beneath the optically clear well bottoms. In an alternative implementation, resistive heater wires are positioned between the wells. In an embodiment, the microtiter plate system includes a microtiter plate lid with an integral heater, which can be implemented using a heater plate, resistive wires, and the like.

Abstract: A surgical and dental instrument sterilizer is described. Liquid water is rapidly vaporized by microwave heating and steam is generated to attain a steam pressure of approximately 47 psi and a temperature of approximately 135° C. in the region of the articles to be sterilized. Micron-size water-droplets are intermittently sprayed onto the articles which are arranged on a tray, from both the top and from underneath thereof so as to thoroughly wet the surfaces. A 30-90 s duration of droplet spray is followed by pulsed microwave irradiation of the top and underneath surfaces for a similar period, as an example; this is followed by a plurality of spray/microwave cycles.

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 method and apparatus for adaptively maintaining the power-frequency spectrum in a reverberation chamber. The invention is thus capable of maintaining a relatively constant power-frequency spectrum in the chamber even when a device under examination is placed into the chamber which exhibits selective frequency absorption and or directional frequency absorption. The object disposed within the chamber need not necessarily be a device under examination. Rather, the present invention can also adaptively maintain a relatively constant power-frequency spectrum when heating any material disposed within a electromagnetic wave chamber.

Abstract: A microwave polymerization system for dentistry utilizes specifically controlled microwave energy to cure polymer materials so as to produce dental prosthetics, such as dentures, bridges and crowns, that are made in an extra-oral setting such as a dental laboratory or dental office, and to create dental composites for fillings and veneers that are used in an intra-oral setting directly in the patient's mouth. Unlike the microwave energy delivered by commercial microwave ovens, the system utilizes metered and controlled microwave energy that is preferably continuous and voltage controlled, and regulates the application of this microwave energy by use of various feedback and control mechanisms. The metered and controlled microwave energy enables a higher degree of conversion of monomers into polymer chains in the polymerization process, thereby enhancing the physical and biocompatibility characteristics of both dental prosthetics and dental composites made from polymers.

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 polymerization system for dentistry utilizes specifically controlled microwave energy to cure polymer materials so as to produce dental prosthetics, such as dentures, bridges and crowns, that are made in an extra-oral setting such as a dental laboratory or dental office, and to create dental composites for fillings and veneers that are used in an intra-oral setting directly in the patient's mouth. Unlike the microwave energy delivered by commercial microwave ovens, the system utilizes metered and controlled microwave energy that is preferably continuous and voltage controlled, and regulates the application of this microwave energy by use of various feedback and control mechanisms. The metered and controlled microwave energy enables a higher degree of conversion of monomers into polymer chains in the polymerization process, thereby enhancing the physical and biocompatibility characteristics of both dental prosthetics and dental composites made from polymers.

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 food amount detector for automatically detecting the amount of a food placed in a cooking chamber of a microwave oven, a microwave oven employing the food amount detector, and control method thereof. Output voltage of a microwave generator is detected while the microwave oven is driven, and the amount of the food placed in the cooking chamber of the microwave oven is determined based on the output voltage such detected. In accordance with the amount of the food such determined, the food is cooked under the appropriate driving conditions of the microwave oven. Accordingly, the user does not need to determine the amount of the food by himself, or set the driving conditions of the microwave oven such as cooking time, level of microwave energy, etc. As a result, the user finds it convenient when using this microwave oven, and the food is cooked under the exact driving conditions set by the microwave oven.

Abstract: Disclosed herein is a microwave oven with a magnetic field detecting device. The microwave oven includes a magnetron for generating microwaves and a wave guide for guiding the microwaves to a cooking chamber. A detection opening is formed in one side of the wave guide to allow a magnetic field generated by standing waves formed in the wave guide to be discharged from the wave guide. The magnetic field detecting device is formed on a board mounted on the wave guide to detect the magnetic field discharged through the detection opening.

Abstract: A microwave polymerization system for dentistry utilizes specifically controlled microwave energy to cure polymer materials so as to produce dental prosthetics, such as dentures, bridges and crowns, that are made in an extra-oral setting such as a dental laboratory or dental office, and to create dental composites for fillings and veneers that are used in an intra-oral setting directly in the patient's mouth. Unlike the microwave energy delivered by commercial microwave ovens which is controlled by pulsing a maximum voltage pulse on and off at a given duty cycle, the system utilizes metered and controlled microwave energy that is preferably continuous and voltage controlled, and regulates the application of this microwave energy by use of various feedback and control mechanisms.

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 data obtaining method for a microwave oven for processing a cooking status of food detected by a sensor into data, including the steps of: detecting data from food for a predetermined time period; calculating a summation of the detected data; and subtracting data about characteristics of the microwave oven which are prestored in the microwave oven from the detected data.

Abstract: A high-frequency detecting element that can detect a temperature increase in an instant due to high-frequency wave absorption using semiconducting ceramic with positive resistance-temperature characteristics. The ceramic is composed mainly of barium titanate. A high-frequency heater incorporating the high-frequency detecting element is also disclosed. In the high-frequency detecting element, electrodes are provided on one main surface of semiconducting ceramic 1 with positive resistance-temperature characteristics and leads 3a and 3b are soldered to the electrodes 2a and 2b.

Abstract: A microwave oven has a stationary wave magnetic field detecting device. The microwave oven includes an antenna sensor having a loop portion which is protruded into a waveguide of the microwave oven, and a wire whose one end is grounded at the waveguide, wherein the wire of the antenna sensor is grounded at an outer side of the waveguide.

Abstract: The invention is directed at apparatus for microwave heating of a ceramic, comprising an adjustable power microwave source for directing microwave power into a continuous throughput microwave cavity. The apparatus further includes a microwave power control system for variably controlling the power of that is delivered to the microwave cavity. The first component of this system comprises a reflected power detector for detecting the microwave power reflected from the ceramic material in the cavity. The reflected power detector measures the value of the reflected power from the cavity and compares that reflected power output value to a preset reflected output value to generate an output signal indicative of the difference in measured and set reflected values.

Abstract: A toploading weighing instrumentality which determines loss on drying by a cylindrical microwave. The cylindrical cavity of the microwave includes a power supply, a magnetron, a power module operatively coupled between said power supply and said magnetron for driving said magnetron, a wave guide communicating with the magnetron and with a microwave containment chamber for delivering energy thereto, at least one microwave energy sensor for sensing microwave energy or magnetic and/or electric field strength within the chamber for controlling, inter alia, the loss on drying process of the sample being assayed and determining when the drying process is complete. A precision electronic balance is operatively disposed within the microwave chamber for allowing a specimen being assayed to be weighed. In addition, a ventilation chamber is provided for venting moisture from the microwave chamber.

Abstract: An improved magnetic field stop. The field stop adjusts to allow different sizes of products to be passed through a microwave heating system. The field stop prevents undue radiation from escaping a heating chamber which is used in a microwave heating process for a variety of substrates.

Abstract: A high frequency heating apparatus for heating an object to be heated is provided with an electromagnetic wave emission device for emitting electromagnetic waves, a local heating device capable of heating an optional portion of the object by the electromagnetic waves emitted from the emission device, and a control device for controlling the local heating device. The high frequency heating apparatus is further provided with a stage on which the object is placed, a protecting device for protecting the local heating device, a setting device and a detection device, so that the local heating device, the electromagnetic wave emission device or the stage is controlled in accordance with the setting device or the detection device.

Abstract: A defrosting method for a microwave oven capable of variably adjusting a level of output power of a magnetron in accordance with data detected from a sensor, comprising the steps of (a) detecting a change degree of output data from a sensor for a predetermined time period; and (b) adjusting a level of output power of a magnetron in accordance with the change degree of the output data from the sensor.

Abstract: A microwave detecting device outputs a first predetermined voltage in accordance with the presence/absence of microwave in a waveguide. A microcomputer inputs the first predetermined voltage, outputs a second predetermined voltage in accordance with the level of the first predetermined voltage, then detects the voltage of an input port of the first predetermined voltage by applying the second predetermined voltage to the input port of the first predetermined voltage, and displays the operational status of the microwave detecting section in accordance with the voltage detected from the input port. The microwave detecting section includes a diode sensor, which is connected between the waveguide and the input port of the microcomputer in a forward direction to output the first predetermined voltage in accordance with the presence/absence of the microwave in the waveguide.

Abstract: A microwave heating apparatus includes a magnetron (6) mounted on a top surface of a wave guide (7). A bottom surface of wave guide (7) is inclined towards the bottom of the wave guide opening. A metal plate (9) is provided with a predetermined clearance above the bottom surface of wave guide (7). The microwaves are irradiated from an antenna (10) of magnetron (6) and travel along the bottom surface of wave guide (7). The microwaves are guided to an opening (8) under regulation by a metal plate (9) dispersion, and thus the microwaves reach the opening without suffering from the loss of energy. An object of heating (1) is irradiated directly by the microwaves with an improved heating efficiency.

Abstract: A method of drying objects includes the steps of placing the objects into a pressure reduction tank, placing a metallic element having a single or plural number of sharp edge into the pressure reduction tank, subjecting the objects to controlled microwave heating and controlled far infrared heating either separately or simultaneously, detecting an electrical discharge at the sharp edge of the metallic element due to microwave energy, stopping or pausing the microwave heating when an electrical discharge is detected at the single or plural number of sharp edge of the metallic element, continuously measuring the change in reduced pressure at prescribed time intervals after the microwave heating has been stopped or paused upon detecting an electrical discharge due to microwave energy, and terminating the drying process when the measured change in reduced pressure reaches a predetermined target reduced pressure change value determined in accordance with the level of dryness selected and the type of the objects be

Abstract: A microwave oven includes a main body, a cooking chamber provided in the main body, and an electrical component compartment containing electrical components, including a magnetron for supplying microwaves to the cooking chamber. Disposed in the cooking chamber is a microwave reflecting varying plate continuously reciprocated by a drive motor during a cooking operation, for reflecting microwaves at continuously varying angles.

Abstract: A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave 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). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Abstract: A load including a plasma discharge in a plasma processing chamber is matched to a variable frequency source so the power reflected from the load is substantially minimized. The source voltage or a variable reactance of a matching network between the source and load is controlled so the load has a preset power level, as detected by the difference between the source output power and the power reflected from the load.

Abstract: A method of drying objects includes the steps of placing the object into a pressure reduction tank, placing a metallic element having an acute-angled portion into the pressure reduction tank, reducing to the pressure toward a predetermined single reduced pressure value or plurality of reduced pressure values, subjecting the object to controlled microwave heating and controlled far infrared heating either separately or simultaneously, continuously heating the body of the pressure reduction tank to vaporize any water that comes into contact with the inside wall surfaces of the pressure reduction tank, detecting an electrical discharge at the acute-angled portion of the metallic element due to microwave energy, stopping or pausing the microwave heating when an electrical discharge is detected at the acute-angled portion of the metallic element, continuously measuring the change in reduced pressure at prescribed time intervals after the microwave heating has been stopped or paused upon detecting an electrical dis

Abstract: The present invention discloses a process for selectively annealing heterostructures using microwaves. A heterostructure, comprised of a material having higher microwave absorption and a material having lower microwave absorption, is exposed to microwaves in the cavity. The higher microwave absorbing material absorbs the microwaves and selectively heats while the lower microwave absorbing material absorbs small amounts of microwaves and minimally heats. The higher microwave absorbing material is thereby annealed onto the less absorbing material which is thermally isolated.

Abstract: A uniform heating apparatus for a microwave oven and a method thereof which are capable of more uniformly heating food by generating various resonant modes based on the kind of food. The apparatus includes an oscillator unit having a wave guide tube for guiding microwaves generated by a magnetron to a lower portion of a heating chamber formed in a microwave oven main body, a resonant mode conversion unit for converting the microwaves guided to the lower portion of the heating chamber to have various resonant modes, a plurality of sensors for detecting the characteristics of food when the microwaves, the resonant mode of which is converted by the resonant mode conversion unit, are supplied to the food in the heating chamber, and a controller for controlling the oscillator unit and the resonant mode conversion unit in accordance with the characteristics of the food detected by the sensors.

Abstract: A high-frequency detecting element that can detect a temperature increase in an instant due to high-frequency wave absorption using semiconducting ceramic with positive resistance-temperature characteristics. The ceramic is composed mainly of barium titanate. A high-frequency heater incorporating the high-frequency detecting element is also disclosed. In the high-frequency detecting element, electrodes are provided on one main surface of semiconducting ceramic 1 with positive resistance-temperature characteristics and leads 3a and 3b are soldered to the electrodes 2a and 2b.

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 microwave oven has a cooking chamber in which a vertically movable turntable is disposed. During the onset of a cooking operation, a control mechanism automatically raises the turntable in step-by-step fashion, and the amount of high frequency waves reflected from the cooking chamber is detected at each vertical position of the turntable. Then, the vertical position of the turntable at which the detected amount of reflective frequency was the lowest is determined, and the turntable is set at that position to continue the cooking operation. If the detected amount of reflective frequency changes, a new vertical position of the turntable at which the amount of reflective frequency is lowest, is re-determined, and the turntable is set at that new position.

Abstract: A device for molding products made of glass or a synthetic resin which device has a microwave generator, a microwave oven coupled to the generator and mold parts movable relative to each other provided in the microwave oven for forming molds for holding a parison of the glass or synthetic resin to be heated dielectrically.

Abstract: A microwave thawing system for thawing bags of frozen blood products features non-invasively monitoring the internal temperature of the blood product during thawing, and controlling the level of warming energy applied to the blood product based on the monitored temperature. The non-invasive monitoring is performed with one or more antennas which receive electromagnetic energy from the frozen blood product during thawing. Because the applied energy level is controlled based on the temperature of the blood, the blood can be thawed rapidly with little risk of damage from overheating. Pressure is applied to the bag to maintain a uniform distribution of blood within the bag and to separate the thawed blood from the still-frozen blood during thawing; for example, the pressure moves the liquid blood to the periphery of the bag and retains the frozen blood in the center of the bag.

Abstract: During operation of a microwave oven, steps are taken to determine whether the oven is being operated in the absence of food therein and to shut down the oven if that state is found to exist. Initially, a high frequency detector disposed in the cooking chamber absorbs high frequency and produces heat in proportion to the absorbed high frequency. A temperature sensor senses the temperature of that produced heat and generates an output signal as a function thereof. After a predetermined time period, that output signal is compared to a reference value which represents a temperature expected to occur in the event that the oven is being operated in the absence of food. If it is determined from that comparison that no food is present in the oven, the oven is deactivated and an alarm is activated.

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).

Abstract: The present invention features a UV tube detector for sensing a resonant arcing condition in a microwave environment. Where clothing or fabric is being dried in a magnetron-powered, microwave chamber, the UV tube detector is placed in proximity to the fabric. The UV tube detector senses a possible resonant arcing condition related to small metal objects hidden in the material. Upon the sensing of arcing, the UV tube provides a signal for shutting down the magnetron power. In conjunction with UV detection, the moisture condition can be monitored during the drying cycle. At a point in the microwave heating cycle consistent with an "end of microwave heating cycle" or "near dryness", the power output of the magnetrons is reduced or terminated. The moist fabric can then be dried via reduced microwave heating and/or by normal heating methods, including, but not limited to, electrical radiant heating and convection techniques.

Abstract: A microwave oven has only a microwave sensor or both microwave sensor and temperature sensor. The microwave sensor has a wave absorber to generate heat through absorption of microwave energy and a thermistor to detect temperature of this wave absorber. The temperature sensor has a thermistor to detect the ambient temperature around the wave absorber. A controller determines a value of microwave power on the basis of the output of the microwave sensor or each output of the microwave sensor and temperature sensor. The microwave oven can accurately detect microwave power without being influenced by variation of ambient temperature around the microwave sensor.

Abstract: A tray useful for the microwave cooking of prepared foodstuffs, particularly frozen foodstuffs, for consumption is structured to provide a more uniform heating of the foodstuff than has heretofore been possible. The tray comprises an outer layer formed of paperboard or molded plastic to which is laminated an inner polymeric film layer. A layer of microwave-reflective material, usually aluminum foil, is positioned between the outer and inner layers in the location of the peripheral wall of the tray and in a pattern in a portion of the bottom wall.