Abstract: The invention relates to a device for simultaneous treatment in a wet medium of four samples contained in four flasks placed in a microwave application cavity, four microwave deflectors being placed inside the application cavity. According to the invention, each deflector is formed by a cylindrical surface that surrounds a fraction of the outside surface of the flask, which fraction lies in the range one-fourth to one-half and the deflectors are symmetrically disposed in pairs about the axis X of the application cavity, and they are disposed for the most part on opposite sides of planes containing the axis X and the two axes of the corresponding flasks, the concave sides of the four deflectors facing in alternating directions.
Abstract: A microwave oven is provided with a removable shelf for dividing a cavity into upper and lower heating zones. Microwave energy from a magnetron is selectively introduced into the upper and lower heating zones to controllably cook separate food items placed therein.
Abstract: A high-frequency heating apparatus capable of heating uniformly a liquid load, having an economical wave guide switching unit and having a compact-sized and economical power circuit to drive a plurality of magnetrons. The high-frequency heating apparatus includes an excitation opening, provided at the bottom of a heating chamber for radiating microwaves to heat the liquid load in a container, a magnetron for generating the microwave to heat the object and a wave guide connected to a magnetron. The apparatus further includes a wave guide switching unity for switching the propagation of the microwave to one of plural wave guides. The switching unit includes a pair of circular conductive plates and a conductor disposed in the vicinity of a circumference of the circular conductive plate so as to shut off the microwave, wherein there is constructed a choke structure on the wave guide containing the circular conductive plates.
Type:
Grant
Filed:
January 22, 1993
Date of Patent:
September 19, 1995
Assignee:
Kabushiki Kaisha Toshiba
Inventors:
Hitoshi Takimoto, Koji Murakami, Tatsuya Nakagawa
Abstract: Microwave energy may be used to dielectrically heat a medium, which can remediate the medium. An apparatus or a system employing this concept is well-suited for various environmental applications, such as in-situ remediation of soil, sludge or spills. The system comprises a microwave energy source having a preselected microwave frequency for emitting microwave energy. The system also comprises a wave-guide section having a cross-section dimensioned in accordance with the wavelength of the microwave frequency for transmitting microwave energy. A broadband mode converter may be disposed in alignment with the wave-guide section. An applicator element is disposed in alignment with the broadband more converter for applying microwave energy directly to the medium without confining the medium, thereby removing contaminants from the medium.
Abstract: A partitioning plate having a configuration which can be inserted into a double wall vacuum container from an opening of vacuum container divides the space of the vacuum container into two spaces. One of the spaces which serves as a heating chamber, is opened and closed by a door. The other space, which serves as a mechanical chamber, accommodates electrical parts. A method for fixing the partitioning plate, on which parts have been installed, to the double vacuum container is faciliated by the provision of a device for regulating the position of the partitioning plate.
Type:
Grant
Filed:
September 29, 1993
Date of Patent:
August 15, 1995
Assignee:
Matsushita Electric Industrial Co., Ltd.
Abstract: A microwave oven includes a cavity in which food is accommodated, a magnetron for generating microwaves, and a waveguide to supply microwaves generated from the magnetron into the cavity. The waveguide has substantially a truncated cone configuration in which the cross sectional area at the cavity side is greater than the cross sectional area at the magnetron side, and an output antenna of the magnetron is disposed to project from the bottom of the waveguide at the magnetron side into the inner space of the waveguide. The microwave oven further includes a flat radiation antenna fixed in the inner space of the waveguide around the output antenna of the magnetron while maintaining distances from the waveguide and the output antenna of the magnetron in which no spark is generated. Therefore, the radiation area for emitting the microwaves is increased significantly to improve heating nonuniformity within the cavity.
Abstract: A microwave oven has a food-receiving cavity the rear panel of which is apertured to provide a launch area for the entry of microwave power to the cavity from a magnetron. A metal plate is positioned in front of a launch area, a central area of the plate having apertures. A forced hot air system comprising a fan and an electrical resistance heating element are positioned between the launch area and the plate. In use, the plate acts as a baffle plate for the hot air system and also as a mis-match plate for the microwave power, so that the dielectric load of food items placed in the cavity determines the microwave power coupled to the loaded oven from the magnetron.
Abstract: A microwave oven, in particular for rapid heating to high temperature, is disclosed. A cylindrical metal housing is open at one end and has a cylindrical side wall, into which a waveguide opens, the waveguide being coupled to a microwave generator. A first outer layer of a thermally insulative, microwave-transparent material and a second inner layer thereof are provided in a coaxial configuration. A metal sleeve provided with plural coupling slots is interposed between the outer and inner layers. A muff of a microwave-absorbing material is received within a central opening of the inner layer and constitutes a heating enclosure. A metal plate fitted with an access door is provided for closing the open end of the housing. An infrared pyrometer or a thermocouple may be provided for measuring temperatures in the heating enclosure. The heating enclosure may have a vent for evacuating fumes and an orifice for injecting gases.
Abstract: The invention relates to a microwave oven which neither generates hot spots nor destroys a magnetron by shutting microwaves when there is no load to be heated. This microwave oven is constructed so that the impedances are matched when there is a load, and the impedances are unmatched when there is no load, by shifting the location of the opening of the cooking chamber from the center of the wave guide. When there is no load, as most of the microwaves are converted to standing waves and the pressing waves do not reach the cooking chamber, then it becomes possible to prevent dangers such as the abnormal irradiation of any part, the destruction of the chamber case owing to the occurrence of the heat spot, and the abnormal heat generation due to the leakage of the short waves.
Abstract: There is disclosed a heating cooking device including a heating chamber for heating an object to be heated, a high-frequency oscillator for generating high-frequency electromagnetic waves, a wave guide for guiding the high-frequency electromagnetic waves from the high-frequency oscillator to the heating chamber, a rotary table for supporting thereon the object to be heated for rotation therewith, and a wave stirrer fan for stirring the electromagnetic waves in the heating chamber. A feeder port of the wave guide is disposed at a side of the heating chamber, and the wave stirrer fan is disposed within the wave guide in opposed relation to the feeder port. The high-frequency oscillator is disposed on the side of the feeder port. The feeder port is larger in size than the wave stirrer fan.
Type:
Grant
Filed:
May 21, 1993
Date of Patent:
December 6, 1994
Assignee:
Matsushita Electric Industrial Co., Ltd.
Abstract: A microwave oven with an oven cavity and a microwave feed system which produces a microwave distribution of polarized microwaves with essentially defined field vector orientations relative to one of the walls of the cavity. A zone defining an expansion of volume which opens into the cavity and whose dimensions are tuned to the wavelength and field distribution in the cavity, is disposed in a wall of the cavity. The expansion does not affect the effective field distribution in the cavity and can be used for concealed placement of a grill element or light source.
Abstract: Waveguide adapted to be mounted on the wall 1 of a cooking chamber between the antenna 2 of a magnetron 3 and an opening 5 provided in the wall 1, and comprising a metallic housing of generally tubular shape formed from a cover 7 comprising an upper elongated wall 8 of which a forward region extends above the wall 1 and of which a rear region extends above the magnetron 3, two side walls 9 and 10, two transverse forward 11 and rear 12 walls, and a base 13 comprising a bottom wall 14 traversed by a hole 16 for passage of the antenna 2 and opening opposite the opening 5. The cover 7 is formed from a single piece obtained by stamping and bending a metal sheet. The invention is applicable to microwave ovens for household use.
Type:
Grant
Filed:
February 20, 1992
Date of Patent:
July 12, 1994
Assignee:
Moulinex (Societe Anonyme)
Inventors:
Michel G. De Matteis, Charles V. L. Patard
Abstract: Apparatus for thawing and reheating a deep-frozen food preparation by microwave and infrared radiation comprises a housing enclosing a heating chamber which is delimited by a tubular wall. The chamber is subjected to microwave radiation from two inlets as well as infrared radiation. The inlets of microwave radiation are arranged in two opposed regions of the tubular wall situated on either side of the central region where the food product is positioned, and the infrared heating elements comprise at least two lamps extending axially of the tubular wall and arranged on either side of the central region in two opposed regions distinct from those of the wave guide openings. A heating process performed using this apparatus involves simultaneously producing continuous microwave radiation by alternately feeding two generators branched in anti-parallel, and continuous infrared radiation, throughout a thawing and reheating cycle.
Type:
Grant
Filed:
January 19, 1993
Date of Patent:
May 17, 1994
Assignee:
Moulinex (Societe Anonyme)
Inventors:
Pierre Chartrain, Jean-Louis M. R. Guilgue