JP2008253373A - Ultrasonic washer, dishwasher using the same, and ultrasonic washing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maximize ultrasonic washing effects on stains with different properties. <P>SOLUTION: This ultrasonic washer is provided with an ultrasonic transducer 2 for vibrating water in a washing tub 1 and washing washed objects, air bubble generation means 3 for supplying air bubbles to the wash water, and control means 7 for controlling the ultrasonic transducer 2 and the bubble generation means 3, and executes ultrasonic washing while generating the air bubbles in the wash water by the control means and continuously or stepwisely changing the air-bubble or gas content in the wash water. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ultrasonic cleaning device, a dishwasher using the same, and an ultrasonic cleaning method.

  Ultrasonic cleaning methods used in the industrial cleaning field include low-frequency ultrasonic cleaning using a frequency of about 20 to 50 kHz and high-frequency ultrasonic cleaning using a frequency in the range of several hundred kHz to several MHz. The cleaning action by the low-frequency ultrasonic vibration is considered to be mainly due to a cavitation phenomenon or an emulsification phenomenon, and is excellent in the effect of peeling off firmly adhered dirt. On the other hand, it is understood that the high-frequency ultrasonic vibration is due to the removal of dirt mainly due to the shake-off effect of acceleration vibration, and is used, for example, to remove micrometer order fine particles remaining on the semiconductor wafer.

  The cavitation phenomenon means that fine bubbles in water called bubble nuclei grow into large bubbles due to low pressure caused by ultrasonic vibration. It is considered that when the grown bubbles contract and collapse at high pressure, a large stress is exerted on the surface of the object to exert a cleaning effect. Since the collapsed bubbles become a large number of fine bubbles to provide new bubble nuclei, the bubble growth and collapse cycle continues and the cleaning effect continues.

  However, when there are few bubble nuclei in water or when the output of the ultrasonic transducer is small and it takes time to grow bubbles, there is a latent period until the cleaning effect is exhibited. Therefore, in order to obtain a sufficient cleaning effect within a limited time, the latent period until the occurrence of cavitation can be shortened by adding bubble nuclei to the cleaning water. Based on such an idea, a technique for adding microbubbles to washing water has been devised (see, for example, Patent Document 1). Further, when the number of bubble nuclei is large, cavitation occurs at a large number of places, so that there is an effect that uneven cleaning due to ultrasonic cleaning is prevented (for example, see Patent Document 2).

In either case, if the size of the bubble to be added is too large or too large, a negative effect (cushion effect) of absorbing and weakening the ultrasonic vibration by the large bubble occurs, so the size of the bubble to be added is Several μm to several tens of μm are preferable. In addition, microbubbles and dissolved gas in water are washed by the surface of the object to be cleaned because bubbles of a size that resonates with ultrasonic vibration are added by adding microbubbles, even in the case of cleaning by high-frequency ultrasonic vibration. A thing is scrubbed (for example, refer patent document 3).
Japanese Utility Model Publication No. 60-193284 Japanese Patent Application Laid-Open No. 64-004285 Japanese Patent Laid-Open No. 06-320124

  When the inventor examined using a 45 kHz ultrasonic cleaner, when the metal with the liquid oil dirt adhered was ultrasonically cleaned, the cleaning effect was high immediately after adding bubbles of several tens of μm, but ultrasonic cleaning was performed. Over time, there was a problem that the cleaning effect decreased. It is unclear why the cycle of bubbles collapsing and creating new bubble nuclei does not continue well, but it seems that microbubbles need to be added continuously.

  Moreover, there existed a thing with a big effect of adding a microbubble depending on the kind and property of dirt adhering to a to-be-washed object, and a thing with no effect recognized. For example, when a 45 kHz ultrasonic cleaner is used, the dry-dried starch paste improves the cleaning effect by adding bubbles of several tens of μm so that the washing water becomes slightly cloudy, but the dried and solidified starch paste The cleaning effect was higher when a smaller amount of bubbles was added. Since the degree of drying of the starch paste stain actually carried into the cleaning line varies, the object to be cleaned with insufficient cleaning effect appears when the amount of bubbles added is uniformly determined.

  An object of the present invention is to realize an ultrasonic cleaning apparatus capable of efficiently cleaning an object to be cleaned with various properties of dirt by devising a method for adding microbubbles.

  In order to solve the above-described conventional problems, the ultrasonic cleaning apparatus of the present invention continuously supplies bubbles suitable for various types of dirt by changing the amount of bubbles generated while generating microbubbles. And ultrasonic cleaning. Moreover, the ultrasonic cleaning apparatus of the present invention is configured to perform ultrasonic cleaning a plurality of times by replacing cleaning water having different bubble contents in the cleaning tank.

  The ultrasonic cleaning apparatus of the present invention can maximize the cleaning effect of the low-frequency ultrasonic cleaning on an object to be cleaned with various surface textures, and has a limited cleaning space and apparatus output. It can be used effectively to exert a cleaning effect.

  1st invention drains the wash water in the washing tank which accommodates to-be-washed | cleaned object, the water supply pipe | tube which introduces washing water into the said washing tank, the water supply valve which opens and closes the said water supply pipe, and the said washing tank A drain pipe, a drain valve that opens and closes the drain pipe, an ultrasonic vibrator that vibrates the water in the cleaning tank to clean the object to be cleaned, and a bubble generating means that generates bubbles or gas in the cleaning water And control means for controlling the operation of the ultrasonic vibrator, the bubble generating means, the water supply valve, and the drain valve, and the control means generates bubbles or gas in the cleaning water while generating bubbles in the cleaning water. Alternatively, ultrasonic cleaning is performed while changing the gas content continuously or stepwise. When the bubble content is relatively large, although the individual collapse stress is small, the cleaning effect is exhibited at a number of points, so that it is suitable for peeling off dirt adhering to a large area with a weak adhesive force. On the other hand, when the bubble content is relatively small, the individual bubble collapse stress is relatively large, which is suitable for peeling off dirt with strong adhesion. By continuously changing the bubble or gas content (hereinafter, abbreviated as bubble content) of the washing water, the number and strength of bubble collapse stresses accompanying the cavitation phenomenon change sequentially. As a result, a sufficient degree of cleaning action can be achieved by sequentially applying appropriate strength and frequency of bubble collapse stress to various types and conditions of tableware stains. In existing dishwashers that use detergent as the main cleaning principle, it takes several minutes to 10 minutes for the cleaning water to permeate the dirt and exert its peeling action, whereas cleaning by ultrasonic cavitation is required. The action is performed in several seconds to several tens of seconds. Therefore, a sufficient cleaning result can be expected only by maintaining the optimum bubble content for several tens of seconds.

  The second invention is a cleaning tank for storing an object to be cleaned, a water supply pipe for introducing cleaning water into the cleaning tank, a water supply valve for opening and closing the water supply pipe, and a drainage for draining the cleaning water from the cleaning tank. A pipe, a drain valve that opens and closes the drain pipe, an ultrasonic vibrator that vibrates water in the cleaning tank to clean the object to be cleaned, and a bubble generating means that generates bubbles or gas in the cleaning water A control means for controlling the operation of the ultrasonic vibrator, the bubble generating means, the water supply valve, and the drain valve, and the control means replaces cleaning water having different bubbles or gas contents in the cleaning tank. And ultrasonic cleaning multiple times. By replacing several types of washing water with different bubble contents in the washing tank, compared with the method of changing the bubble content of the same washing water, the rinsing effect can be expected, so the washing effect is improved and the number of times of rinsing is reduced Time reduction can be expected.

  In the third aspect of the invention, in particular, the control means of the first or second aspect of the invention increases the amount of bubbles or gas generated in the washing water during the ultrasonic cleaning. When the ultrasonic cleaning is completed, the bubble content is maximized, so the bubbles merge to form a larger bubble (in the order of several hundreds of micrometers), and the floating separation technology that adsorbs dirt around the bubble and lifts it up. In combination, it is possible to prevent redeposition of dirt.

  In the fourth aspect of the invention, in particular, the control means of the first or second aspect of the invention reduces the amount of bubbles or gas generated in the washing water during the ultrasonic cleaning. If a relatively large amount of bubbles are added before the start of ultrasonic cleaning, the bubble generating means is operated at an output smaller than the maximum output thereafter, so that the power consumption used simultaneously with the ultrasonic transducer can be kept small.

  According to a fifth aspect of the invention, in particular, the bubble generating means according to any one of the first to fourth aspects includes a hydrophobic and highly breathable hollow fiber membrane and a gas-dissolving membrane module comprising an outer space of the hollow fiber membrane. A pump for pressurizing the external space of the gas-dissolving membrane module, and passing cleaning water through the gas-dissolving membrane module to pressurize the external space of the hollow fiber membrane with the pump to dissolve the gas. Is. In the case of this method, the amount of gas dissolved in the washing water can be easily and continuously changed by changing the pressure for pressurizing the external space of the gas-dissolving membrane module.

  In particular, the sixth invention is a pressurizing / depressurizing pump in which the pump of the fifth invention can perform both pressurization and depressurization, and the washing water is obtained by pressurizing or depressurizing the external space of the hollow fiber membrane of the gas dissolving membrane module. The gas can be dissolved and degassed. By depressurizing the pump, it is also possible to degas from the wash water, and the gas dissolution amount of the wash water can be varied widely from degassing to dissolved gas addition. As a result, the ultrasonic cleaning effect can be optimized for dirt having a wider range of characteristics.

  In the seventh invention, in particular, the bubble generating means of the first to fourth inventions has at least one pair of electrodes and a current applying means for applying a current to the electrodes. Alternatively, a gas is generated, and a current value to be applied is changed to change a generation amount of bubbles or gas. Electrolysis of water molecules in the washing water generates hydrogen gas micro bubbles from the cathode and oxygen gas from the anode. The amount of bubble generation can be easily changed by changing the applied current. In particular, hydrogen gas microbubbles are said to be instantly exposed to high temperature and pressure by cavitation to generate hydrogen radicals. A chemical cleaning effect by hydrogen radicals is also expected.

  In the eighth aspect of the invention, in particular, the electrode of the seventh aspect of the invention is located in the cleaning tank and holds the object to be cleaned. Only the cavitation phenomenon that occurs near the surface of the object to be cleaned exhibits the cleaning effect. If the object to be cleaned is held from the bottom by the electrode, it is considered that most of the generated bubbles are floated in the vicinity of the object to be cleaned, so that cavitation can be caused most efficiently.

  In the ninth aspect of the invention, in particular, since the bubble generating means of the first to fourth aspects of the invention is an ejector, it is possible to add bubbles to the cleaning water with a simple configuration.

  In the tenth aspect of the invention, in particular, the ejector of the ninth aspect of the invention is provided with a variable amount of air intake, and by changing the amount of air intake to change the amount of bubble generation, it has a simple configuration. The amount of bubbles generated can be changed.

  An eleventh invention is a dishwasher including the ultrasonic cleaning device according to any one of the first to tenth inventions. When ultrasonically cleaning dishes with a wide variety of dirt, by changing the bubble content of the washing water continuously, each bubble is given appropriate strength and frequency of bubble collapse. A sufficient cleaning action can be exhibited. As a result, the amount of detergent used can be reduced, the washing time can be shortened, the ultrasonic output required for washing can be reduced, and therefore the body of the dishwasher can be made smaller.

  The twelfth invention is an ultrasonic cleaning method in which ultrasonic cleaning is performed while changing the bubble content of the cleaning water continuously or stepwise. When ultrasonically cleaning an object to be cleaned with a wide variety of dirt, it is possible to sequentially change the bubble content of the washing water to obtain the appropriate strength and frequency of bubble collapse force for each dirt. To give a sufficient cleaning action. As a result, the amount of detergent used can be reduced, the cleaning time can be shortened, and the ultrasonic output required for cleaning can be reduced.

  A thirteenth aspect of the invention is an ultrasonic cleaning method in which cleaning water having different bubble contents is replaced in a cleaning tank to perform ultrasonic cleaning a plurality of times. When ultrasonically cleaning an object to be cleaned with a wide variety of dirt, it is possible to sequentially change the bubble content of the washing water to obtain the appropriate strength and frequency of bubble collapse force for each dirt. To give a sufficient cleaning action. As a result, the amount of detergent used can be reduced, the cleaning time can be shortened, and the ultrasonic output required for cleaning can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of a dishwasher according to a first embodiment using the ultrasonic cleaning apparatus of the present invention. The dishwasher includes a washing tank 1 for storing dishes to be washed, an ultrasonic vibrator 2 for vibrating the washing water in the washing tank 1, a gas dissolving membrane module 3 for dissolving or degassing the gas in the washing water, and a gas Pressurizing / depressurizing pump 4 for driving the dissolving membrane module 3, pressurizing pump 5 with a valve for switching ON / OFF and introduction direction of cleaning water, drain valve 6 for switching ON / OFF of drainage of cleaning water and draining direction, Control means 7 for controlling the opening / closing and switching direction of the water supply valve and drain valve by driving the sonic vibrator 2, the overflow pipe 8 for overflowing when the water in the cleaning tank 1 accumulates above a predetermined water level, and draining the cleaning water A drain pipe 9 for performing cleaning, a water supply pipe 10 for introducing washing water, and a filter 11 for filtering dirt components from washing water containing dirt.

  Since the dishwasher using the ultrasonic cleaning apparatus of the present invention can take a plurality of operating modes for the change in the dissolved gas saturation of the washing water, first, the outline of the change in the bubble content will be described with reference to FIG. To do. The cleaning method is roughly classified into an ascending formula (a) for increasing the direction of change in the bubble content of the washing water during the ultrasonic cleaning process and a descending formula (b) for decreasing.

  In the ascending method, the amount of bubbles generated is maximized when the ultrasonic cleaning is completed, so that the separated dirt components are adsorbed around a large number of bubbles and lifted to remove them for the purpose of preventing the reattachment of dirt. There is a merit that it can be combined with the separation method. On the other hand, in the descending type, the ultrasonic transducer 2 can be operated by operating the pressurizing / depressurizing pump 4 as the bubble generating means at the maximum output before starting the ultrasonic cleaning so that the cleaning water contains the maximum amount of bubbles. After the start, it is only necessary to operate the pressure-reducing pump 4 with a smaller output, and the maximum power consumption of the ultrasonic cleaning apparatus as a whole can be reduced.

  The method of changing the bubble content in both the ascending method and the decreasing method is a method of changing the bubble content of the same washing water (continuous method: a), There is a method of continuously supplying and replacing the cleaning water (continuous replacement formula: b), a method of draining the original cleaning water and then introducing cleaning water with a different bubble content (replacement formula: c) is there.

  The continuous type has the feature that it uses the least amount of washing water. The continuous replacement type is inferior in water saving performance to the continuous type, but cleaning is performed while discharging dirt, so that the reattachment of dirt is suppressed and the amount of rinsing water used is small. In the replacement type, it is usually necessary to perform cleaning with a bubble content of three or more stages. Since the cleaning water is discarded every time the replacement is performed, the amount of cleaning water used is the largest.

  The operation will be described below with respect to the continuous replacement ascending method (a-b) and the continuous descending method (b-i), which are relatively suitable for the present method, but other methods are also possible.

  First, the operation in the continuous displacement ascending formula (a-b) will be described with reference to FIG. The ultrasonic cleaning process before the rinsing process is shown in FIG. The cleaning water supplied from the water supply pipe 10 is introduced in the direction of arrow A to fill the cleaning tank 1 to the depth of the overflow pipe 8. At that time, the gas-dissolving membrane module 3 and the pressurizing / decompressing pump 4 are not operated, and the gas is not dissolved and the bubbles are not supplied. The ultrasonic vibrator 2 is activated to start ultrasonic cavitation cleaning. The frequency of the ultrasonic transducer that can be used can range from about 20 kHz to 2 MHz, but a frequency of about 50 kHz is used from the viewpoint that cavitation can be caused with low power consumption and noise in the audible range is less likely to occur. Cheap.

  Two to three minutes after the start of the ultrasonic vibration, the pressurizing pump 5 with the valve opened and the gas was added while the gas-dissolving membrane module 3 was activated by operating the pressure-reducing pump 4 in the pressurizing direction. Washing water is supplied to the washing tank 1. While continuing the ultrasonic cleaning, the pressurizing / depressurizing pump 4 gradually raises the positive pressure to increase the amount of gas to be dissolved. When the dissolved gas concentration reaches a certain level, the gas that cannot be dissolved in water appears as minute bubbles. It is preferable that the pressure of the pressurizing / depressurizing pump 4 and the flow rate of the pressurizing pump 5 with a valve are set in advance so that bubbles having a diameter of several μm to several tens of μm are generated.

  At this time, the discharge valve 6 is open in the direction of the overflow pipe 8, and the same amount of cleaning water as that supplied with gas or bubbles is discharged from the overflow pipe 8 in the direction of arrow B. Most of the added bubbles are disrupted by ultrasonic vibration, and at that time, a collapse pressure is generated on the surface of the tableware to exert a cleaning action. After the ultrasonic cleaning for a total of about 10 minutes is completed, the supply of the cleaning water to which the pressure increasing / depressurizing pump 4 has added bubbles at the maximum capacity is continued for several minutes.

  Among the separated dirt components, hydrophobic substances, for example, some proteins such as fats and oils, egg yolks, and granular dirt such as pepper grains are adsorbed around a large amount of bubbles, floated and separated, and discharged from the overflow pipe 8. Thereafter, the drain valve 6 is switched in the direction of the drain pipe 9, and all the washing water is drained in the direction of the arrow c. By performing flotation separation, the above-mentioned dirt is prevented from adhering to the tableware surface when the water level is lowered. As a result, it is sufficient to rinse once or at most twice.

  As another example of the operation method, the operation in the continuous descending type (b-i) will be described with reference to FIG. The ultrasonic cleaning process before the rinsing process is shown in the flowchart in FIG. After about 1 minute in the state where the pressure increasing / decreasing pump 4 is operated at the maximum capacity in the pressurizing direction and the gas dissolving membrane module 3 is operated, the valved pressure pump 5 is opened in the direction of the arrow A and the bubbles are added. Water is supplied to the washing tank 1. When the cleaning water to which bubbles are added fills the cleaning tank 1 up to the height of the overflow pipe 8, the pressure pump 5 with a valve is switched in the direction of arrow D. In a state where bubbles are continuously added at the maximum capacity, the ultrasonic vibrator 2 is operated and ultrasonic cleaning is started. The ultrasonic frequency and preferred bubble diameter are as described above. Several minutes after the start of ultrasonic cleaning, the operation output of the pressurizing / depressurizing pump 4 is gradually reduced to reduce the amount of bubbles added. After the output of the pressurizing / depressurizing pump 4 is reduced to zero over about 5 minutes, the operating direction of the pressurizing / depressurizing pump 4 is switched to depressurization and ultrasonic cleaning is continued for about 5 minutes.

  In this way, the ultrasonic cleaning is continued for a total of 15 minutes while changing the bubble content of the cleaning water widely, so that the soils having various characteristics are cavitation cleaned under the optimum conditions and peeled off. After stopping the ultrasonic vibration, the drain valve 6 is opened, and the washing water is discharged in the direction of arrow c. Thereafter, rinsing is repeated twice to complete the cleaning process. In the case of the continuous descending type (b-i) and the continuous ascending type (a-i), since the dirt component suspended in the washing water is filtered by the filter 11, the filter 11 is cleaned after operation.

(Embodiment 2)
FIG. 5 shows a block diagram of the dishwasher in the second embodiment of the present invention. The dishwasher is used for electrolysis for adding bubbles to the washing tank 1, the ultrasonic vibrator 2, the washing water, the electrode 12 also serving as a tableware holder, the ON / OFF of the introduction of the washing water, and the introduction direction. Pressurized pump 5 with valve, drain valve 6 for switching drainage ON / OFF and drainage direction, driving ultrasonic transducer 2 and applying current to electrodes to control opening / closing and switching direction of feed valve and drain valve Control means 7, an overflow pipe 8 that overflows when the water in the washing tank accumulates above a predetermined level, a drain pipe 9 that drains the washing water, a water supply pipe 10 that introduces the washing water, and dirt It is comprised from the filter 11 which filters a dirt component from washing water.

  As for the electrode 12, a positive electrode and a cathode are arrange | positioned alternately. When a platinum electrode having a diameter of 5 mm and a length of 50 to 100 mm is used as the electrode, the cathode and the anode are alternately arranged, and a direct current of 1-2 A is applied, a remarkable cleaning effect appears. The amount of bubbles generated can be changed by changing the current value to be applied. Since the applied voltage can be kept relatively small by using the salt contained in the tableware stain as an electrolysis auxiliary agent, the present embodiment is a continuous ascending (a-i) or continuous descending ( It is most suitable to use in b-i).

  The operation in the continuous ascending type (a-i) will be described with reference to FIG. The cleaning water introduced from the water supply pipe 10 is supplied to the cleaning tank 1 in the direction of the arrow a. When the cleaning water is filled to the depth of the overflow pipe 8, the vibration of the ultrasonic vibrator 2 is started. Two to three minutes later, the flow path of the pressure pump 5 with valve is switched in the direction of the arrow D, and a current starts to be applied to the electrode 12. The applied current is controlled to gradually increase, whereby the amount of microbubbles generated gradually increases. After the ultrasonic cleaning is continued for about 10 minutes, the operation of the ultrasonic vibrator 2 and the current application to the electrodes are stopped. The direction in which the direct current is applied is reversed, and the maximum current within a predetermined range is continuously applied to the electrode 12 for about 3 minutes to generate bubbles.

  Of the soil components peeled off by ultrasonic cleaning, highly hydrophobic oils and fats, some proteins, particulate soil, etc. adsorb around the fine bubbles and float on the water surface. After that, the valve-equipped pressure pump 5 introduces a small amount of washing water and causes the floated dirt to overflow from the overflow pipe 8. Thereafter, the drain valve 6 is switched in the direction of the drain pipe 9, and all the washing water is drained in the direction of the arrow c. By performing flotation separation, the above-mentioned dirt is prevented from adhering to the tableware surface when the water level is lowered. As a result, it is sufficient to rinse once or at most twice.

  The present embodiment is different from the other embodiments in that minute bubbles are concentrated and supplied in the vicinity of the tableware that is the object to be cleaned. Since only bubbles on the tableware surface exert a cleaning action when disintegrating by ultrasonic waves, it is most efficient to supply bubbles only on the surface of the tableware. Moreover, by doing so, it can also prevent that microbubbles unite in places other than tableware and grow into the big bubble which weakens an ultrasonic vibration.

  In addition, the point that hydrogen gas and oxygen gas microbubbles generated by electrolysis of washing water are added is significantly different from the other embodiments. Since the gas in the bubble is instantaneously heated to several thousand degrees or pressurized to several tens of MPa at the moment when the bubble collapses, an oxidizing radical is generated. Oxidation by radicals also contributes to the removal and partial decomposition of dirt, and enhances the cleaning power against chemically adhered dirt such as tea astringents.

(Embodiment 3)
FIG. 6 shows a block diagram of a dishwasher according to the third embodiment of the present invention. The dishwasher is equipped with a washing tub 1, an ultrasonic vibrator 2, an ejector 13 that is provided with a variable flow rate of suction air, adds bubbles to the washing water, and is pressurized with a valve that switches ON / OFF of the introduction of the washing water and the introduction direction. Control means for controlling pump 5, drainage valve 6 for switching on / off of drainage of washing water and drainage direction, driving ultrasonic transducer 2 and opening / closing and switching direction of water supply valve and drainage valve to ejector 7. From the overflow pipe 8 that overflows when the water in the washing tank accumulates above a predetermined water level, the drain pipe 9 that drains the washing water, the water supply pipe 10 that introduces the washing water, and the washing water containing dirt It is comprised from the filter 11 which filters a dirt component.

  The ratio of the inner diameter of the ejector to the inner diameter of the throttle is set to 1/3 or less so that the sucked air bubbles are sufficiently miniaturized. Moreover, it is preferable that the inner diameter of the throttle portion is about 3-4 mm so that dirt is not clogged in the throttle portion. In the case of an ejector having a large inner diameter of 10 mm and a throttle portion of 3 mm, the amount of air supplied to the ejector is controlled between 0 and 25% of the flow rate of the washing water. The smaller the flow rate, the smaller the bubbles that are generated.

  The operation in the continuous ascending type (a-i) will be described with reference to FIG. The cleaning water introduced from the water supply pipe 10 is supplied to the cleaning tank 1 in the direction of the arrow a. At that time, the intake flow rate of the ejector 13 is controlled to zero, and no bubbles are added. When the cleaning water is filled to the depth of the overflow pipe 8, the vibration of the ultrasonic vibrator 2 is started. After 2-3 minutes, the flow path of the valved pressurizing pump 5 is switched in the direction of arrow D, and the intake air flow rate of the ejector 13 is gradually increased. After continuing ultrasonic cleaning for about 10 minutes, the operation of the ultrasonic vibrator 2 is stopped. The valved pressure pump 5 continues to operate for about 3 minutes to generate bubbles at the maximum intake amount.

  Of the soil components peeled off by ultrasonic cleaning, highly hydrophobic oils and fats, some proteins, particulate soil, etc. adsorb around the fine bubbles and float on the water surface. After that, the valve-equipped pressure pump 5 introduces a small amount of washing water and causes the floated dirt to overflow from the overflow pipe 8. Thereafter, the drain valve 6 is switched in the direction of the drain pipe 9, and all the washing water is drained in the direction of the arrow c. By performing flotation separation, the above-mentioned dirt is prevented from adhering to the tableware surface when the water level is lowered. As a result, it is sufficient to rinse once or at most twice.

(Embodiment 4)
FIG. 7 shows a configuration diagram of a dishwasher according to the fourth embodiment of the present invention. The dishwasher is provided with an ultrasonic washing nozzle 14 provided to contain the washing tub 1, the ultrasonic vibrator 2, and the ultrasonic vibrator 2 and spray the washing water toward the dishes, and for adding bubbles to the washing water. Gas-dissolving membrane module 3 and pressurizing / depressurizing pump 4, pressurizing pump 5 with a valve for switching ON / OFF and introduction direction of cleaning water, drain valve 6 for switching ON / OFF of drainage of cleaning water and draining direction, super Control means 7 for controlling the amount of air supply to the ejector 2 to drive, the opening and closing of the water supply valve and the drain valve, and the switching direction, and an overflow pipe for overflowing when the water in the cleaning tank accumulates above a predetermined water level 8. A drain pipe 9 for draining the cleaning water, a water supply pipe 10 for introducing the cleaning water, and a filter 11 for filtering dirt components from the cleaning water containing dirt.

  Compared with the first to third embodiments, the present embodiment has an advantage that it can be designed to be light and small because it does not have a large water storage section. In addition, the total amount of cleaning water consumed can be reduced, and the number and output of ultrasonic vibrators can be reduced for this purpose, resulting in high resource saving performance.

  The operation in the continuous ascending type (a-i) will be described with reference to FIG. The washing water introduced from the water supply pipe 10 is supplied to the water storage tank 16 and the gas dissolution membrane module 3 in the direction of arrow A. At that time, the operation of the pressurizing and depressurizing pump 4 is not started, and bubbles are not added. The washing water is pressurized in the direction of arrow B by the pressurizing pump 15, fills the inside of the ultrasonic vibration nozzle 14, and starts vibration of the ultrasonic vibrator 2. The washing water is jetted toward the tableware while propagating ultrasonic vibrations, and exhibits a cleaning action by cavitation on the surface of the tableware.

  The washing water that has flowed down from the tableware gathers in the water storage tank 16, is pressurized again, and is sprayed onto the tableware. Two to three minutes after the start of ultrasonic cleaning with cleaning water to which bubbles are not added, the pressurizing / depressurizing pump 4 operates in the pressurizing direction to start adding bubbles. The amount of bubbles added is gradually increased with the pump operating time. After the ultrasonic cleaning is continued for about 10 minutes, the operations of the ultrasonic vibrator 2 and the pressure-reducing pump 4 are stopped. Thereafter, the pressurizing pump 15 switches the flow path in the direction of the arrow C, and all the washing water is drained from the drain pipe 9. Thereafter, rinsing is performed about twice, and the cleaning process is completed.

  As described above, the ultrasonic cleaning apparatus according to the present invention can maximize the cleaning effect of low-frequency ultrasonic cleaning on an object to be cleaned with various surface textures. It is useful as an ultrasonic cleaning apparatus that effectively uses the cleaning space and apparatus output.

The block diagram of the dishwasher using the ultrasonic cleaning apparatus in Embodiment 1 of this invention Explanatory drawing which shows the system of the ultrasonic cleaning method of this invention Flowchart of continuous replacement ascending method of ultrasonic cleaning method of the present invention Continuously descending flowchart of the ultrasonic cleaning method of the present invention The block diagram of the dishwasher using the ultrasonic cleaning apparatus in Embodiment 2 of this invention The block diagram of the dishwasher using the ultrasonic cleaning apparatus in Embodiment 3 of this invention The block diagram of the dishwasher using the ultrasonic cleaning apparatus in Embodiment 4 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Washing tank 2 Ultrasonic vibrator 3 Gas dissolution membrane module (bubble generation means)
5 Pressure pump with valve (water supply valve)
6 Drain valve 7 Control means 9 Drain pipe 10 Water supply pipe

Claims (13)

A cleaning tank for storing an object to be cleaned; a water supply pipe for introducing cleaning water into the cleaning tank; a water supply valve for opening and closing the water supply pipe; a drain pipe for draining the cleaning water in the cleaning tank; A drain valve that opens and closes a pipe, an ultrasonic vibrator that vibrates water in the cleaning tank to clean the object to be cleaned, a bubble generating means that generates bubbles or gas in the cleaning water, and the ultrasonic vibration And a control means for controlling the operation of the water supply valve and the drain valve. The control means continuously generates bubbles or gas content in the wash water while generating bubbles or gas in the wash water. Ultrasonic cleaning device that performs ultrasonic cleaning while changing the target or steps. A cleaning tank for storing the object to be cleaned, a water supply pipe for introducing cleaning water into the cleaning tank, a water supply valve for opening and closing the water supply pipe, a drain pipe for draining the cleaning water from the cleaning tank, and the drain pipe A drain valve that opens and closes, an ultrasonic vibrator that vibrates water in the cleaning tank to clean the object to be cleaned, a bubble generating means that generates bubbles or gas in the cleaning water, and the ultrasonic vibrator And control means for controlling the operation of the bubble generating means, the water supply valve, and the drain valve, and the control means replaces cleaning water having different bubbles or gas contents into the cleaning tank and performs ultrasonic cleaning multiple times. An ultrasonic cleaning device. The ultrasonic cleaning apparatus according to claim 1 or 2, wherein the control means increases the amount of bubbles or gas generated in the cleaning water during the ultrasonic cleaning. The ultrasonic cleaning apparatus according to claim 1 or 2, wherein the control means reduces the amount of bubbles or gas generated in the cleaning water during the ultrasonic cleaning. The bubble generating means has a hydrophobic and highly breathable hollow fiber membrane, a gas dissolving membrane module comprising an outer space of the hollow fiber membrane, and a pump for pressurizing the outer space of the gas dissolving membrane module, The ultrasonic cleaning apparatus according to claim 1, wherein the gas is dissolved by passing the gas through the gas-dissolving membrane module and pressurizing the external space of the hollow fiber membrane with the pump. The pump is a pressurizing / depressurizing pump that can perform both pressurization and depressurization. The gas dissolution membrane module can be dissolved and degassed by pressurizing or depressurizing the external space of the hollow fiber membrane of the gas dissolving membrane module. Item 6. The ultrasonic cleaning apparatus according to Item 5. The bubble generating means has at least one pair of electrodes and current applying means for applying a current to the electrodes, generates bubbles or gas by electrolysis of washing water, and changes the applied current value to change the bubbles or gas. The ultrasonic cleaning apparatus according to claim 1, wherein the generation amount of gas is changed. The ultrasonic cleaning apparatus according to claim 7, wherein the electrode is located in the cleaning tank and holds an object to be cleaned. The ultrasonic cleaning device according to claim 1, wherein the bubble generating means is an ejector. The ultrasonic cleaning apparatus according to claim 9, wherein the ejector is provided with a variable amount of air intake, and the amount of air bubble generation is changed by changing the amount of air intake. The dishwasher provided with the ultrasonic cleaning apparatus of any one of Claims 1-10. An ultrasonic cleaning method in which bubbles or gas is supplied to cleaning water and ultrasonic cleaning is performed while changing the supply amount continuously or stepwise. An ultrasonic cleaning method wherein ultrasonic cleaning is performed a plurality of times by replacing cleaning water having different bubbles or gas contents in the cleaning tank.