JPH105165A - Dish washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide waterless washing by providing a pressure reducing means for reducing the pressure in a washing chamber, a gas feed means for feeding a prescribed volume of gas, and a high voltage power supply for applying high voltage to electrodes, reducing the pressure in the washing chamber, feeding gas therein, and washing a dish by plasma discharge across the electrodes. SOLUTION: In operating a dish washer 1, at first, dishes 2 to be washed are mounted between electrodes 3, 3 in a washing chamber 5. Secondly, when the washing chamber 5 is closed and sealed, a vacuum pump 8 is started so as to reduce the pressure in the washing chamber 5, and after reaching a prescribed vacuum degree, a feed air flow adjustment valve 13 is opened so that a prescribed volume of gas is started to flow in. At the same time, the current whose voltage is increased by a high voltage power supply is fed to the electrodes 3, 3 so as to excite across the electrodes 3, 3 into a plasma state P. This constitution permits the gas present between the electrodes 3, 3 to become an excited state, resolves and vaporizes the dirt stuck to the surface of the dishes 2, and sucks and disposes the vaporized dirt in the vacuum side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry dishwasher which does not use water in a washing process.

[0002]

2. Description of the Related Art A conventional dishwasher, for example, a dishwasher for washing dishes using washing water, as shown in FIG.
The tableware 53 is placed on a cupboard 52 in the washing tank 51, and the washing water stored in the lower part of the washing tank 51 is pumped together with a special detergent.
At the nozzle 55 to wash the tableware 53,
Thereafter, the washing water is replaced, rinsing is performed, rinsing is performed several times, and then drying is performed.

As a cleaning machine for performing cleaning using plasma, a plasma etching machine used for pretreatment for coating resin, precision cleaning for electric and electronic parts, and pretreatment for bonding is used for industrial purposes. It is used. There is an apparatus for ashing an object using plasma as an ashing apparatus for analysis.

In these devices (techniques), a predetermined gas suitable for each purpose is introduced into a chamber in a vacuum, and the gas is supplied to the chamber.
The process is performed by supplying a high frequency such as 3.56 MHz to the chamber to generate plasma. In some cases, this device generates a voltage of tens of thousands KV at normal pressure as well as vacuum.

As an invention relating to a vacuum chamber in the above-described cleaning apparatus, as described in Japanese Patent Application Laid-Open No. Hei 6-220668, a plasma is generated between spaces on a plurality of shelves for storing a plurality of processing objects in a vacuum chamber. The one provided with the above electrode has been proposed.

[0006]

As described above, in a conventional dishwasher, water and a detergent are used as washing means. Therefore, when the dishwasher is installed by using water, Installation work such as water supply piping such as branching from a normal faucet and piping for washing and draining after dishwashing is required, and the installation place is limited because the dishwasher can not be separated from near the water supply at the time of installation In addition, it is a fact that water pollution caused by the use of detergents has a problem of environmental pollution.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide an environment-friendly dishwasher which is a dry type which does not use water in a washing process and which is not troublesome in its place.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to the first aspect of the present invention is directed to a dishwasher having a vacuum-resistant washing room provided with a door. A pressure reducing means for reducing the pressure of the washing chamber to a predetermined pressure, a gas supply means for supplying a predetermined amount of gas, and a high-voltage power supply for applying a high voltage to the electrode, comprising an electrode and means for placing tableware between the electrodes. After the pressure in the cleaning chamber is reduced, a gas is supplied to cause a plasma discharge between the electrodes, and the placed tableware is cleaned by the plasma.

[0009] The invention according to claim 2 provides, in addition to the configuration of the invention according to claim 1, a method for performing effective cleaning.
After the tableware is placed, the door is sealed, the pressure adjusting means for reducing the pressure to a reduced pressure value of 30 Torr or less, and the gas amount adjusting means for supplying a gas for improving a predetermined amount of cleaning efficiency after the pressure reduction, The plasma cleaning is performed by providing high voltage adjusting means for applying an inter-electrode voltage suitable for the reduced pressure value and time measuring means for applying the high voltage between the electrodes for a predetermined time.

[0010] The invention according to claim 3 is based on claim 1.
In addition to the configuration of the invention described, in order to keep the cleaning chamber at a predetermined strength even when a vacuum pressure is applied a predetermined number of times or more, the entire or a part of the cleaning chamber of the dishwasher has a curved surface that expands outward. The door part is made of stainless steel and has a sealed structure.

According to a fourth aspect of the present invention, in addition to the configuration of the first aspect of the present invention, as means for improving the heat resistance and corrosion resistance of the electrode, a conductive ceramic is used on the opposing surface of the electrode. It is. Further, claim 5
According to the invention described above, in addition to the configuration of the invention described in claim 1, in order to stabilize the generated plasma, the shelf on which the tableware is placed is formed of an insulating ceramic or resin or glass, or the surface thereof is made of them. Is formed of a coated metal chamber or a synthetic resin or ceramic.

Further, the invention according to claim 6 is provided with a dry vacuum pump in order to keep the inside of the vacuum chamber clean in addition to the structure of the invention according to claim 1. According to a seventh aspect of the present invention, in addition to the configuration of the first aspect of the present invention, as means for shortening the time required for complete cleaning during cleaning, gas is separated from the atmosphere using gas separating means. It utilizes the oxygen obtained.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The dishwasher of the present invention is a dry dishwasher that does not require water for washing by using plasma when washing dishes, and a high voltage is applied to a vacuumed washing chamber. By applying the gas, the gas sealed in the chamber is excited into a plasma state, and the sealed gas excited in the plasma state has a very high electron temperature and a very high oxidizing power, and the plasma is applied to the surface of the tableware. By touching the contaminants, the contaminants gradually become gas from the surface, and eventually break down completely into gas to wash the dishes.

Hereinafter, a first embodiment of a dishwasher according to the present invention will be described with reference to FIGS.

A dishwasher according to a first embodiment of the present invention is configured as shown in FIG. 1. In FIG.
The dishwasher 1 includes a tableware 2 to be cleaned, an electrode 3 located in a cleaning chamber and facing to generate plasma, a high voltage power supply 4 for applying a high voltage current to the electrode 3, and a tableware 2 to be cleaned. Vacuum-resistant cleaning chamber 5 that can be housed, and wiring 15 for supplying high voltage to electrode 3
An insulating sealing material 16 which maintains insulation even when a high voltage is applied between the cleaning chamber 5 and the wiring 15 and does not cause air leakage; a rack 6 in the chamber 5 for placing tableware; , A rack holder 7 for holding the space between the opposing electrodes 3, a vacuum pump 8 for drawing a predetermined vacuum in the chamber 5, and a connection between the vacuum pump 8 and the vacuum cleaning chamber 5. Exhaust pipe 9 and exhaust port 10 for exhausting gas, and air supply port 1 for sending gas into chamber 5 from outside of chamber 5
1, an air supply pipe 12, an air supply flow rate control valve 13 for adjusting the flow rate of gas to be supplied, and an electrode holder 14 for holding the electrode 3 without the cleaning chamber 5.

Next, the operation of the dishwasher constructed as described above will be described. First, tableware 2 to be washed
Is placed between the opposing electrodes 3 in the cleaning chamber 5. At this time, the rack 6 is attached to the rack holder 7
Place on top and secure. The rack can be placed directly on the electrode 3 without any problem.

After the work of storing the tableware 2 is completed, the washing chamber 5 is closed and sealed, and then the vacuum pump 8 is started to start reducing the pressure in the washing chamber 5. 13 is opened to start the flow of a predetermined gas, and the current boosted by the high-voltage power supply 4 is supplied to the electrode 3 with the start of the flow of the gas.

When a high voltage is applied to the electrodes 3, the space between the electrodes 3 is excited to a plasma state P,
The gas existing in between is in an excited state, and the excited gas decomposes and vaporizes the contamination attached to the tableware 2 surface,
The vaporized contamination is sucked to the vacuum side and discarded.
The plasma is irradiated for a predetermined time, and the cleaning process is completed. Thereafter, the supply air flow control valve 13 is released to return to the atmospheric pressure.
The dishes are washed as described above.

FIG. 2 shows the result of the cleaning as described above. From these results, it is possible to perform cleaning with plasma, and it is desirable that the pressure in the cleaning chamber 5 be 30 Torr or less for generation of plasma. Taking into account the appropriate amount of gas for washing dishes and the low rise of plasma, the most desirable value is around 1 Torr. Further, it is necessary to perform the cleaning while taking a certain amount of virgin gas into the chamber 5 as a gas serving as a cleaning medium.

In the above case, the rack must be made of an insulating material. This is because placing the conductor in the plasma hinders stable plasma generation. Further, it is desirable that the vacuum pump 8 is a dry vacuum pump that does not use oil. This is because the oil rotary pump may cause oil mist to scatter on the vacuum side,
Since the oil deteriorates depending on the number of times of use and time, it is necessary to change the oil. For these reasons, a dry vacuum pump is suitable.

Preferably, the inflow gas is oxygen. Because the active species of oxygen directly contribute to the oxidation of contaminants, the high oxygen concentration of the gas is very useful for cleaning. According to the cleaning test, when air was used and when oxygen was used, cleaning was possible in about half the time in the case of oxygen.

Next, a second embodiment of the dishwasher according to the present invention will be described with reference to FIGS.

The dishwasher according to the second embodiment of the present invention is configured as shown in FIG. 3, and FIG. 3 is a schematic perspective view of a washing chamber of the dishwasher according to the present invention.
3, a cleaning chamber 20 (corresponding to the cleaning chamber 5 in FIG. 1) includes a door 21 that can be opened and closed, a knob 22 that facilitates opening and closing of the door 21, and a hinge that supports the door 21 and keeps the door 21 openable and closable. 23, a vacuum seal portion 24 provided at a contact portion between the door 21 and the main body, an exhaust port 25 of a vacuum pump, and a power transmission portion 26 for supplying power to the electrodes.
And an air supply portion 27 and a door lock 28 for assisting a vacuum seal.

When the material is made of stainless steel and swelled and reinforced as shown in FIG. 3, the thickness is 2 mm or less and sufficient strength can be maintained. SUS3 among stainless steel
04 is appropriate. As means for further reducing the plate thickness, it is necessary to introduce reinforcement into the side plate so as to be inclined at right angles to the direction of the wall surface as shown in FIGS. 4 (a) and 4 (b). By providing a plurality of such reinforcements, the plate thickness can be reduced.

Next, a third embodiment of the dishwasher according to the present invention will be described with reference to FIGS. 5 (a) and 5 (b).

A dishwasher according to a third embodiment of the present invention is configured as shown in FIGS. 5 (a) and 5 (b).
FIG. 5A is a schematic perspective configuration diagram of an electrode of the dishwasher of the present invention, and FIG. 5B is a schematic cross-sectional configuration diagram of an electrode of the dishwasher of the present invention.

5A and 5B, the electrode plate 30
Is molded from a conductive ceramic,
An electrode plate 31 formed of ceramic;
1 includes an electric power supply terminal 32 for supplying electric power to the power supply terminal 1 and an insulating shield 33 around the electric power supply terminal 32 for preventing the plasma 34 from entering the electric power supply terminal 32.

As a conductive ceramic material, silicon carbide is very useful because it is less deformed by heat and has excellent corrosion resistance, and among ceramics, a dense ceramic is more useful. This is to prevent the generation of gas adsorbed in the case of porous ceramics when the chamber is evacuated to a vacuum. Depending on the pumping capability, evacuation of 30 Torr or less is sufficiently possible even with a porous structure. Although the power supply terminal 32 and the electrode plate 31 can be formed integrally, it is possible to form the power supply terminal 32 and the electrode plate 3 made of stainless steel.
It is also possible to bond and mold 1 using a conductive paste represented by silver or the like. It is desirable that the insulating shield 33, the electrode plate 31, and the power supply terminal 32 be made of materials having similar thermal expansion coefficients.

[0029]

Since the dishwasher of the present invention has the above-described structure, the invention according to claim 1 mounts the facing electrode in a vacuum-resistant washing room having a door and the tableware between the electrodes. And a gas supply means for supplying a predetermined amount of gas, and a high-voltage power supply for applying a high voltage to the electrodes. After the pressure is reduced, a gas is supplied to cause a plasma discharge between the electrodes, and the placed tableware is washed with the plasma, so that the place where the dishwasher is placed can be separated from the surroundings of the tap water. Since the cleaning is performed, environmental effects are completely harmless. Further, since the installation place is free, there is an effect that no installation work is required.

The invention according to claim 2 has the effect of the invention according to claim 1, and furthermore, after the tableware is placed on the shelf, the door is sealed and the pressure is adjusted to reduce the pressure to a reduced pressure value of 30 Torr or less. Means, gas amount adjusting means for supplying a gas for improving a predetermined amount of cleaning efficiency after decompression, high voltage adjusting means for applying an inter-electrode voltage suitable for the reduced pressure value, and a predetermined time between the electrodes. And a timer for applying the high voltage to perform the plasma cleaning so that stable generation of plasma can be easily obtained.

[0031] The third aspect of the present invention provides the first aspect.
In addition to the effects of the described invention, the cleaning chamber is made of stainless steel having a curved surface which swells in whole or in part or outwards, and the door portion is constituted by a sealed structure, so that a vacuum chamber can be manufactured at low cost.

Further, according to the invention of claim 4, in addition to the effect of the invention of claim 1, since the opposing surface of the electrode is made of conductive ceramic, there is little deformation due to heat and stable discharge. A condition is obtained, which allows a stable washing of the dishes.

Further, according to the invention described in claim 5, in addition to the effect of the invention described in claim 1, the shelf for placing tableware is formed of an insulating ceramic, resin, or glass, or has a surface made of them. A stable discharge of plasma can be obtained because the metal chamber coated with is formed of synthetic resin or ceramic.

[0034] Further, in addition to the effect of the first aspect of the present invention, in addition to the effect of the first aspect of the present invention, the use of a dry vacuum pump for the pressure reducing means prevents oil mist from entering the cleaning chamber from the vacuum pump. Can be lost,
In addition, it is possible to make user maintenance free.

According to a seventh aspect of the present invention, in addition to the effect of the first aspect of the present invention, since the gas is made of oxygen obtained by separating from the atmosphere using a gas separating means, the gas is washed with ordinary air. It is possible to wash faster than before.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a dishwasher according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a cleaning rate of the dishwasher of the present invention.

FIG. 3 is a schematic configuration perspective view showing a second embodiment of the dishwasher of the present invention.

FIG. 4 is an explanatory cross-sectional view of a method for reinforcing a vacuum chamber of a dishwasher according to the present invention.

FIG. 5 is a schematic configuration diagram of an electrode of the dishwasher of the present invention.

FIG. 6 is a schematic sectional configuration view showing an embodiment of a conventional dishwasher.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dishwasher 2 Tableware 3 Electrode 4 High voltage power supply 5 Cleaning chamber 8 Vacuum pump 13 Supply air flow control valve 20 Cleaning chamber 24 Vacuum seal part 30 Ceramic electrode 31 Electrode plate 32 Power supply terminal 33 Insulation shield

Claims (7)

[Claims] 1. An apparatus according to claim 1, further comprising: an opposite electrode in a vacuum-resistant cleaning chamber having a door; and means for placing tableware therebetween.
A pressure reducing means for reducing the pressure of the cleaning chamber to a predetermined pressure, a gas supply means for supplying a predetermined amount of gas, and a high voltage power supply for applying a high voltage to the electrodes are provided. A dishwasher characterized in that dishwashers placed by plasma discharge between electrodes are washed with plasma. 2. After the tableware is placed, the door is closed and sealed.
A pressure adjusting means for reducing the pressure to a reduced pressure value of Torr or less, a gas amount adjusting means for supplying a gas for improving a predetermined amount of cleaning efficiency after the pressure reduction, and applying an inter-electrode voltage suitable for the reduced pressure value. 2. The dishwasher according to claim 1, wherein the dishwasher is provided with a high voltage adjusting means for performing the plasma cleaning and a time measuring means for applying the high voltage between the electrodes for a predetermined time. 3. The dishwasher according to claim 1, wherein the washing chamber is entirely or partially made of stainless steel having a curved surface bulging outward, and a door portion has a sealed structure. 4. The dishwasher according to claim 1, wherein the opposing surface of the electrode is made of a conductive ceramic. 5. The means for installing the tableware is characterized in that it is an insulating ceramic or resin or glass or a metal chamber coated with glass or a shelf made of synthetic resin or ceramic. The dishwasher according to claim 1. 6. The dishwasher according to claim 1, wherein said pressure reducing means is a dry vacuum pump. 7. The dishwasher according to claim 1, wherein the gas comprises oxygen obtained by separating the gas from the atmosphere using a gas separating means.