Microwave heating device

Patent metadata

Field	Value
Publication number	US-2021249229-A1
Application number	US-201817251449-A
Country	US
Kind code	A1
Filing date	Jul 2, 2018
Priority date	Jul 2, 2018
Publication date	Aug 12, 2021
Grant date	—

Abstract

What is provided here are: a radiation element provided at one of walls of a heating chamber, for radiating a microwave into the heating chamber; at least one hollow dielectric member in which a gas is sealed, the hollow dielectric member having electrodes at both end portions thereof; and a control unit having a plasma control unit for controlling the state of the hollow dielectric member and a current adjustment unit for adjusting a current to be applied to the electrodes of the hollow dielectric member, under the control of the plasma control unit, the current adjustment unit being connected to the electrodes; wherein the at least one hollow dielectric member is provided along one of the walls which is other than the wall at which the radiation element is provided; and wherein the plasma control unit controls the state of the hollow dielectric member so that it is put into one of states of: a plasma state in which the microwave is reflected by the gas; a plasma state in which the microwave is absorbed by the gas; and a gas state in which the microwave is allowed to be transmitted through the gas.

First claim

1 . A microwave heating device, comprising:
a heating chamber capable of storing therein a heating target and having walls each made of a conductor; a microwave generator to generate a microwave; at least one radiation element to radiate, into the heating chamber, the microwave generated by the microwave generator, the radiation element being provided at one of the walls; at least one hollow dielectric member in which a gas is sealed, the hollow dielectric member having electrodes at both end portions thereof; and processing circuitry to control a state of the hollow dielectric member; and to adjust a current to be applied to the electrodes of the hollow dielectric member, the processing circuitry being connected to the electrodes; wherein the at least one hollow dielectric member is provided along one of the walls which is other than the wall at which the radiation element is provided; and wherein the processing circuitry controls the state of the hollow dielectric member so that the hollow dielectric member is put into one of states of: a plasma state in which the microwave is reflected by the gas; a plasma state in which the microwave is absorbed by the gas; and a gas state in which the microwave is allowed to be transmitted through the gas.

2 . The microwave heating device of claim 1 , wherein the at least one hollow dielectric member includes two or more hollow dielectric members provided in a line along the wall which is other than the wall at which the radiation element is provided; and
wherein the processing circuitry controls states of respective two or more hollow dielectric members among the hollow dielectric members provided in a line so that the respective two or more hollow dielectric members are put into the plasma state in which the microwave is reflected.

3 . The microwave heating device of claim 2 , wherein the at least one hollow dielectric member includes: two or more hollow dielectric members provided in a line at respective positions about 0.25 wavelength away from a first wall among the walls which is other than the wall at which the radiation element is provided; and two or more hollow dielectric members provided in a line at respective positions about 0.25 wavelength away from a second wall among the walls which is other than the wall at which the radiation element is provided, the second wall being opposite to the first wall across the heating target; and
wherein the processing circuitry performs control to make switching between: a first set of states in which the hollow dielectric members provided in a line along the first wall are put into the plasma state in which the microwave is reflected while the hollow dielectric members provided in a line along the second wall are put into the gas state in which the microwave is allowed to be transmitted; and a second set of states in which the hollow dielectric members provided in a line along the second wall are put into the plasma state in which the microwave is reflected while the hollow dielectric members provided in a line along the first wall are put into the gas state in which the microwave is allowed to be transmitted.

4 . The microwave heating device of claim 3 , wherein the processing circuitry acquires temperature information indicating a temperature distribution in the heating chamber, and refers to a database in which one or more control settings for controlling the state of each of the hollow dielectric members are stored, to thereby acquire one of the control settings which is matched with the acquired temperature information;
wherein the processing circuitry controls the state of each of the hollow dielectric members in accordance with the control setting acquired; and wherein the processing circuitry adjusts the current to be applied to the electrodes.

5 . The microwave heating device of claim 4 , wherein the processing circuitry acquires the temperature information after change of the plasma state by the processing circuitry, and performs updating by causing the database to associate the temperature information before and after the change of the plasma state with a corresponding one of the control settings and to store resultant data; and
wherein the processing circuitry refers to the database after the updating, to thereby acquire one of the control settings on a basis of the temperature information that is currently given and the temperature information before and after application of the current.

6 . The microwave heating device of claim 4 , wherein the hollow dielectric members include rows of hollow dielectric members provided in a line along one of the walls which crosses the wall at which the radiation element is provided, the rows along the wall being stacked; and
wherein the processing circuitry controls the current to be applied to the electrodes, in accordance with the control setting acquired, to thereby perform control of the hollow dielectric members so that any given adjacent three or more of the members are put into the plasma state in which the microwave is reflected, and hollow dielectric members other than the three or more are put into the gas state in which the microwave is allowed to be transmitted.

7 . The microwave heating device of claim 2 , comprising two or more radiation elements included in the at least one radiation element;
wherein the microwave generator has a phase shifter to make a difference in phase between microwaves each of which is the microwave radiated by a corresponding one of the two or more radiation elements; wherein the hollow dielectric members include two or more hollow dielectric members provided in a line along one of the walls which crosses a straight line extending in an alignment direction of the two or more radiation elements; and wherein the processing circuitry controls at least one of the hollow dielectric members provided in a line, to be put into the plasma state in which the microwave is absorbed.

8 . The microwave heating device of claim 7 , wherein the radiation elements include two or more radiation elements aligned in a first alignment direction and two or more radiation elements aligned in a second alignment direction;
wherein the phase shifter makes a difference in phase between the radiation elements each provided in a corresponding one of the first alignment direction and the second alignment direction; wherein the hollow dielectric members include two or more hollow dielectric members provided in a line along one of the walls which crosses a straight line extending in the first alignment direction, and two or more hollow dielectric members provided in a line along one of the walls which crosses a straight line extending in the second alignment direction; and wherein the processing circuitry controls: at least one of the hollow dielectric members provided along the wall which crosses the straight line extending in the first alignment direction; and at least one of the hollow dielectric members provided along the wall which crosses the straight line extending in the second alignment direction; to be put into the plasma state in which the microwave is absorbed.

9 . The microwave heating device of claim 8 , wherein the hollow dielectric members include stacked rows of the hollow dielectric members provided in a line along the wall which crosses the straight line extending in the first alignment direction, and stacked rows of the hollow dielectric members provided in a line along the wall which crosses the straight line extending in the second alignment direction.

10 . The microwave heating device of claim 5 , wherein the hollow dielectric members include rows of hollow dielectric members provided in a line along one of the walls which crosses the wa

Assignees

• Mitsubishi Electric Corp

Inventors

• Suenobu Hiroshi
• Yamaura Shingo
• Tanaka Tai
• Takikawa Michio

Classifications

• H05B6/70 Primary

  Feed lines · CPC title

• H01J37/32311

  Circuits specially adapted for controlling the microwave discharge · CPC title

• H05B6/806

  for laboratory use · CPC title

• H01J37/32926

  Software, data control or modelling · CPC title

• H01J37/32201 Primary

  Generating means · CPC title