JP7185390B2 - Cleaning methods, washing machines, dishwashers, and toilet bowls - Google Patents

Description

Embodiments of the present invention relate to cleaning methods, washing machines, dishwashers, and toilet bowls.

In recent years, microbubbles with a particle size of several tens of nanometers to several micrometers, called microbubbles or nanobubbles, have attracted attention, and techniques for washing objects using microbubble water containing a large number of microbubbles have been developed. Proposed. Here, for example, when cleaning oil stains or the like, it is common to use a surfactant such as a detergent. However, in the conventional structure, the interaction between the microbubbles and the surfactant has not been sufficiently verified, and the effect of the interaction between the microbubbles and the surfactant has not been sufficiently obtained.

Japanese Patent Application Laid-Open No. 2006-43103

Therefore, the present invention provides a cleaning method capable of enhancing the cleaning efficiency by drawing out the effect of the interaction between microbubbles and a surfactant, and a washing machine, a dishwasher, and a toilet using this cleaning method.

In the washing method according to the present embodiment, laundry, tableware, Alternatively, in the cleaning method for cleaning a toilet bowl , the microbubble water accounts for 50% or more of the microbubbles with a particle diameter of 100 nm±30 nm in the number of microbubbles with a particle diameter of 500 nm or less. Alternatively, at least two peaks including the maximum peak fall within the range of 100 nm±30 nm in particle size in the number distribution for each diameter of microbubbles with a particle size of 500 nm or less.

In addition, the washing machine, the dishwasher, and the toilet according to the present embodiment mix microbubble water containing 1×10^5 or more microbubbles per 1 ml with a particle size of 500 nm or less, and a surfactant. The microbubble water is a washing method in which laundry, tableware, or a toilet bowl is washed with a washing liquid, and the microbubble water is microbubbles with a particle size within the range of 100 nm ± 30 nm, which accounts for the number of micro bubbles with a particle size of 500 nm or less. The ratio of the number of bubbles is 50% or more, or at least two peaks including the maximum peak in the number distribution for each diameter of fine bubbles with a particle size of 500 nm or less are within the range of 100 nm ± 30 nm in particle size. It's settled.

FIG. 2 is a graph showing the number distribution for each particle size of microbubbles contained in microbubble water used in the cleaning method according to one embodiment; FIG. 4 is a table showing the relationship between the particle size and the number of microbubbles contained in the microbubble water used in the cleaning method according to the embodiment; FIG. 4 is a table showing evaluation results of cleaning performance of a cleaning method according to an embodiment; FIG. 2 is a graph showing evaluation results of cleaning performance of a cleaning method according to an embodiment; Sectional view schematically showing an example of a microbubble generator used in the cleaning method according to one embodiment FIG. 5 is a cross-sectional view of the microbubble generator used in the cleaning method according to one embodiment, taken along line X6-X6 in FIG. A diagram schematically showing the configuration of a measurement system for measuring the number distribution for each particle size of microbubble water used in the cleaning method according to one embodiment. FIG. 2 is a graph showing the results of microbubble water measured by a measurement system for use in a cleaning method according to an embodiment; FIG. 1 is a diagram conceptually showing the interaction between microbubbles and a surfactant in the cleaning method according to one embodiment (part 1); FIG. 2 is a diagram conceptually showing the interaction between microbubbles and a surfactant in the cleaning method according to one embodiment (part 2); FIG. 3 is a diagram conceptually showing the interaction between microbubbles and a surfactant in the cleaning method according to one embodiment (Part 3). FIG. 4 is a diagram conceptually showing the interaction between microbubbles and a surfactant in the cleaning method according to one embodiment (Part 4). FIG. 5 is a diagram conceptually showing the interaction between microbubbles and a surfactant in the cleaning method according to one embodiment (No. 5). A diagram showing a schematic configuration of a washing machine according to one embodiment

An embodiment will be described below with reference to the drawings.
As shown in FIGS. 1 and 2, the present embodiment is microbubble water containing 1×10̂5 or more microbubbles with a particle diameter of 500 nm or less per 1 ml, more preferably microbubbles with a particle diameter of 250 nm or less. is a cleaning method for cleaning an object to be cleaned with a cleaning solution, ie, a surfactant solution, in which microbubble water containing 1×10̂5 or more per 1 ml of microbubbles and a surfactant are mixed. In this embodiment, the surfactant may be a naturally derived surfactant such as soap, or a synthetic surfactant contained in a synthetic detergent or the like. Soaps and synthetic detergents may be in solid, liquid or powder form.

Microbubble water refers to water or a solution containing a large amount of microbubbles having nano-order diameters. That is, the microbubble water used in the cleaning method of the present embodiment contains a large amount of microbubbles having nano-order particle sizes compared to tap water. Microbubbles are generated by locally reducing the cross-sectional area of a channel through which a liquid such as water flows, thereby rapidly depressurizing the liquid passing through the channel, thereby precipitating dissolved air in the liquid. be able to. Microbubbles can also be generated by, for example, mixing external air at high speed into a liquid such as water passing through a channel.

As shown in FIG. 1, the microbubble water used in the cleaning method of the present embodiment has a maximum peak P1 of the number distribution for each diameter of microbubbles having a particle diameter of 500 nm or less, that is, for each particle diameter, within a particle diameter range of 100 nm±70 nm. More preferably, the particle diameter is within the range of 100 nm±50 nm, more preferably within the range of 100 nm±30 nm. In this case, the maximum peak P1 of the number distribution for each particle size of microbubbles appears near the particle size of 80 nm.

Also, the second peak P2 appears around a particle diameter of 140 nm, and the third peak P3 appears around a particle diameter of 110 nm. The fourth peak P4 appears around a particle diameter of about 50 nm, and the fifth peak P5 appears around a particle diameter of 220 nm. In the present embodiment, at least two peaks including the maximum peak P1 in the number distribution for each diameter of microbubbles with a particle diameter of 500 nm or less, in this case, the maximum peak P1 and the third peak P3, have a particle diameter of 100 nm ± It is within the range of 30 nm.

The microbubble water used in the cleaning method of the present embodiment is set so that the ratio of the number of microbubbles with a particle diameter of 100 nm±30 nm to the number of microbubbles with a particle diameter of 500 nm or less is 50% or more. ing. In the case of this embodiment, as shown in FIG. 2, the microbubble water contains 1.0×10^6 or more microbubbles per 1 ml with a particle diameter of 500 nm or less, in this case, about 1.25×10^6. contains. Among them, about 8.25×10̂5 microbubbles have a particle diameter within the range of 100 nm±30 nm. Therefore, in the microbubble water, the ratio of the number of microbubbles with a particle diameter of 100 nm±30 nm to the number of microbubbles with a particle diameter of 500 nm or less is approximately 66%.

The inventors of the present application used the microbubble water described above to verify the correlation between the number of microbubbles in the cleaning liquid and the rate of improvement in cleaning performance against sebum stains according to the following procedure. In addition, microbubbles in this verification mean those having a particle diameter of 500 nm or less.

(Preparation of contaminant components of artificial sebum stains)
Oleic acid and triolein were dissolved in chloroform as a solvent, and a 50% solution containing 32.5% oleic acid and 17.5% triolein was used as the contaminant.

(Artificial contamination and preparation of samples)
A 150 mm×200 mm piece of cotton cloth was evenly impregnated with 40 ml of the staining component solution, air-dried in a room for 24 hours, and then cut into 50 mm square pieces to obtain the stained cloth. In addition, a cotton cloth that had not been impregnated with the solution of the contaminating component was used as the raw cloth.

(test method)
One of the stained fabrics served as a reference piece without washing. Further, the six contaminated cloths were each treated with a cleaning solution containing 1.30×10̂6 microbubbles/ml, a cleaning solution containing 6.5×10̂5/ml microbubbles, and a cleaning solution containing 3.25×10̂5 microbubbles/ml. cleaning solution containing microbubbles/ml, cleaning solution containing microbubbles of 2.6×10^5/ml, cleaning solution containing microbubbles of 1.60×10^5/ml, and mixing microbubbles It was washed with six kinds of washing liquids that were not used, and then naturally dried in a room for 24 hours. As a result, evaluation pieces 1 to 5 and a comparative piece were obtained.

The same amount of detergent is dissolved in each cleaning liquid. That is, the washing liquid for washing the comparative piece was prepared by dissolving a specified amount of commercially available detergent in tap water. The washing liquid for washing evaluation pieces 1 to 5 was obtained by dissolving a specified amount of commercially available detergent in tap water mixed with the above-mentioned prescribed microbubbles. The dissolved amount of the detergent is, for example, the specified amount described in the instruction manual of the detergent. In addition, the comparison piece and each evaluation piece 1 to 5 were washed using a commercially available washing machine under the same operating conditions.

Next, Oil Violet was dissolved as an oil-soluble dye in an ethanol aqueous solution solvent with a mixing ratio of ethanol:water=13:7 to obtain a staining solution with a concentration of 0.664 mg/ml. Then, each of the evaluation pieces 1 to 5 and the comparative piece is immersed in the staining solution for 15 minutes and dyed, then rinsed with an ethanol aqueous solution and water in that order to rinse off the excess staining solution, then the comparative piece and each evaluation piece 1. ˜5 and comparative pieces were air-dried indoors for 24 hours.

Next, using a color difference meter, the color difference between the raw cloth and the reference piece was measured as the color difference before washing of each evaluation piece 1 to 5 and the comparative piece. Further, the color difference between the original fabric and each of the evaluation pieces 1 to 5 and the comparison piece was measured as the color difference after washing of each evaluation piece 1 to 5 and the comparison piece. Then, the cleaning degrees of the evaluation pieces 1 to 5 and the comparative pieces were calculated based on the following formula (1), and the cleaning degrees of the evaluation pieces 1 to 5 were compared with the washing degree of the comparative pieces.
Degree of washing = 1 - (color difference after washing)/(color difference before washing) (1)

The results of the tests are shown in FIG. In addition, the “mixing ratio” in FIG. It shows the ratio of microbubble water to the entire cleaning liquid when the cleaning liquid is purified by mixing. "Microbubble concentration" in FIG. 3 indicates the number of microbubbles contained in 1 ml of each cleaning liquid. The "logarithmic value" in FIG. 3 represents the microbubble concentration of each cleaning liquid using a common logarithm with 10 as the base.

According to the test results shown in FIG. 3, the evaluation piece 1 washed with a washing liquid containing 1.30×10^6 microbubbles/ml was compared to the comparative piece washed with a washing liquid containing no microbubbles. On the other hand, an improvement in cleaning performance of 19.2% was observed. In addition, in the evaluation piece 2 that was washed with the washing liquid containing 6.5 × 10^5 microbubbles/ml, 13.7% of the comparative piece washed with the washing liquid that did not contain microbubbles. An improvement in cleaning performance was observed. In addition, in the evaluation piece 3 washed with the washing liquid containing 3.25 × 10^5 microbubbles/ml, 13.0% of the comparative piece washed with the washing liquid containing no microbubbles An improvement in cleaning performance was observed.

In addition, in the evaluation piece 4 washed with the washing liquid containing 2.6 × 10^5 microbubbles/ml, 12.6% of the comparison piece washed with the washing liquid containing no microbubbles An improvement in cleaning performance was observed. Then, in the evaluation piece 5 washed with the washing liquid containing 1.60 × 10^5 microbubbles/ml, 10.7% of the comparative piece washed with the washing liquid containing no microbubbles An improvement in cleaning performance was observed.

In FIG. 4, the logarithm of the number of microbubbles in the cleaning liquid is plotted on the horizontal axis, and the rate of improvement in cleaning performance is plotted on the vertical axis, for each evaluation piece 1 to 5 in FIG. In FIG. 4, the horizontal axis, that is, the concentration of microbubbles in the cleaning liquid, is the X axis, and the vertical axis, that is, the cleaning performance improvement rate is the Y axis. ). Also, the correlation coefficient R^2 in this case was 0.908.
Y=(5.02×10̂(−4))X̂(3.25) (2)

According to FIG. 4, formula (2), and its correlation coefficient R̂2, as the amount of microbubbles in the cleaning liquid increases, the cleaning performance improves almost linearly, that is, almost linearly. Recognize. That is, it was found from this test that there is a high correlation between the number of microbubbles in the cleaning liquid and the cleaning performance. Then, according to the formula (2), when the number of microbubbles in the cleaning liquid is 1.0×10̂5/ml, that is, X=5, when cleaning is performed with a normal cleaning liquid that does not contain microbubbles, It is derived that the cleaning performance is improved by about 9.4% compared to the above. Further, according to the formula (2), when the number of microbubbles in the cleaning liquid was 1.26×10̂5/ml, that is, X=5.1, cleaning was performed with a normal cleaning liquid containing no microbubbles. It is derived that the cleaning performance is improved by about 10% compared to the case. As a result, by including at least 1.0×10^5 microbubbles/ml in the cleaning liquid, the cleaning performance is improved by about 10% compared to cleaning with a normal cleaning liquid that does not contain microbubbles. was found to be improved.

Here, in the above test, microbubble water was generated using the microbubble generator 10 shown in FIGS. The microbubble generator 10 is made of synthetic resin, for example, and formed in a cylindrical shape as a whole. The microbubble generator 10 has a constricted portion 11 , a straight portion 12 and a projecting portion 13 . The narrowed portion 11 and the straight portion 12 form one continuous flow path. In this case, the narrowed portion 11 side is the input side, and the straight portion 12 side is the output side.

The narrowed portion 11 has a shape in which the inner diameter decreases from the input side to the output side of the fine bubble generator 10, that is, a so-called conical tapered tubular shape in which the cross-sectional area of the flow path, that is, the inner diameter, gradually decreases continuously. formed. The straight portion 12 is formed in a cylindrical, so-called straight tubular shape in which the cross-sectional area of the flow path, that is, the inner diameter does not change.

The projecting portion 13 is provided in the middle of the straight portion 12 in the longitudinal direction. The projecting portion 13 is for locally reducing the cross-sectional area through which water can pass in the straight portion 12 to generate fine bubbles in the liquid passing through the straight portion 12 . In the case of this embodiment, the straight portion 12 is provided with a plurality of, in this case, four projecting portions 13 . Each protruding portion 13 is formed of a rod-shaped member with a sharp tip, and protrudes from the inner peripheral surface of the straight portion 12 toward the center of the cross section of the straight portion 12 . The protruding portions 13 are arranged in a state of being spaced apart from each other at equal intervals in the circumferential direction of the cross section of the straight portion 12 .

When water flows into the micro-bubble generator 10 from the narrowed portion 11 side, the cross-sectional area of the flow path is narrowed from the narrowed portion 11 to the straight portion 12, thereby increasing the flow velocity due to the so-called venturi effect of hydrodynamics. Then, the high-speed flow collides with the projecting portion 13, causing a rapid drop in pressure. As a result, a large amount of air dissolved in water can be precipitated as fine bubbles.

The evaluation of the performance of the micro-bubble generator 10 is included per unit amount of micro-bubble water, for example, 1 ml, when water is passed through the micro-bubble generator 10 once to generate micro-bubble water. This is done by measuring the number of microbubbles and the number distribution for each particle size of the microbubbles. In this embodiment, passing water through the micro-bubble generator 10 only once to generate micro-bubble water is referred to as one-pass.

Evaluation of the performance of the microbubble generator 10 is performed using a measurement system 20 as shown in FIG. The measurement system 20 includes a microbubble generator 10 , a water tank 21 , a circulation pump 22 , and pipes 23 and 24 connecting the water tank 21 and the circulation pump 22 . The fine bubble generator 10 is provided in the middle of the pipe 23 connected to the discharge side of the circulation pump 22 , that is, in the middle of the pipe 23 from the circulation pump 22 to the water tank 21 .

A predetermined amount of ultrapure water W, for example, 10 L, is stored in the water tank 21 . The circulation pump 22 circulates the ultrapure water W between the water tank 21 and the circulation pump 22 . At that time, ultrapure water W is applied to the microbubble generator 10 at a pressure of 0.1 MPa by the action of the circulation pump 22 . As a result, microbubbles are deposited in the ultrapure water W that has passed through the microbubble generator 10 to form microbubble water. Then, the circulation pump 22 is driven for a predetermined time to circulate the ultrapure water W to pass through the microbubble generator 10 a plurality of times, thereby increasing the number of microbubbles contained in the ultrapure water W in the water tank 21. rice field.

The inventor of the present application took samples of the ultrapure water W in the water tank 21 every predetermined time, for example, about 10 minutes after the circulation pump 22 was started to be driven. Then, the inventors of the present application analyzed each collected sample by a nanoparticle tracking method (also referred to as a particle trajectory tracing method) using a nanoparticle analyzer (NANOSIGHT LM10, manufactured by Shimadzu Corporation). The number of microbubbles was counted.

Further, the inventor of the present application calculated the time required for one circulation of the ultrapure water W from the circulation flow rate of the ultrapure water W and the initial storage amount in the water tank 21 . In the case of this embodiment, the time required for one circulation is about 1 minute. Then, the inventor of the present application calculated the number of times the ultrapure water W passed through the microbubble generator 10 until each sample was collected from the time required for one circulation and the sample collection time. In the following description, the number of times calculated in this way, that is, the number of times the ultrapure water W is thought to have passed through the microbubble generator 10 from the operation of the circulation pump 22 to the time of collection of each sample, is used. called the number of times.

FIG. 8 plots the number of passages for each sample on the horizontal axis and the amount of microbubbles generated on the vertical axis. According to the results of FIG. 8, it was found that the amount of microbubbles contained in the ultrapure water W increases linearly as the number of passages, that is, the number of circulations of the ultrapure water W increases. In other words, it was found that the more the ultrapure water W passes through the microbubble generator 10, the more the microbubbles in the ultrapure water W are concentrated. That is, according to the results of FIG. 8, the number of passes through the microbubble generator 10, that is, the number of circulations of the ultrapure water W, and the amount of microbubbles contained in the ultrapure water W have a first-order linear correlation. I understood it.

According to this, if the number of microbubbles generated when a liquid such as water is passed through the microbubble generator 10 once is defined as the one-pass performance of the microbubble generator 10, then the one-pass performance of the microbubble generator 10 is Performance is determined as follows. That is, the ultrapure water W in the water tank 21 is sampled at an arbitrary point after the start of circulation, and the number of microbubbles contained in the sample is counted. By dividing the number of microbubbles thus measured by the number of passages, that is, the number of circulations up to the sampling time, the one-pass performance of the microbubble generator 10 is calculated. The performance calculated in this way, that is, the number of microbubbles, is averaged by the number of passages after increasing the concentration once, so the resolution of the measuring device and the influence of fine particles other than microbubbles contained in the water used can be eliminated as much as possible, and highly accurate evaluation results can be obtained.

According to the results shown in FIG. 8, in this embodiment, about 1.48×10̂7 microbubbles with a particle diameter of 500 nm or less are generated per 1 ml by 10.6 cycles of circulation. Approximately 2.85×10̂7 fine bubbles with a particle size of 500 nm or less are generated per 1 ml by 20.2 times of circulation. Approximately 3.95×10̂7 fine bubbles with a particle size of 500 nm or less are generated per 1 ml by 29.8 times of circulation. From these results, it can be seen that 1.3 to 1.4×10̂6 microbubbles with a particle size of 500 nm or less were generated per 1 ml by one pass. Therefore, the microbubble generator 10 used in the cleaning method of the present embodiment generates microbubble water containing about 1.3 to 1.4×10̂6 microbubbles per 1 ml with a particle diameter of 500 nm or less. It was found that it can be generated in one pass at 0.1 MPa.

In the cleaning performance test described above, microbubble water obtained by passing tap water through the microbubble generator 10 only once, that is, microbubble water generated in one pass, was defined as 100% microbubble water. This 100% microbubble water contains about 1.3×10̂6 microbubbles per 1 ml with a particle size of 500 nm or less. Then, this 100% microbubble water was used as a stock solution without being diluted with tap water to obtain a washing liquid containing 1.30×10̂6 microbubbles/ml used for evaluation piece 1. Also, by diluting 100% microbubble water with tap water to 50%, a washing liquid containing 6.50×10̂5 microbubbles/ml used for evaluation piece 2 was obtained.

Also, by diluting 100% microbubble water with tap water to 25%, a washing liquid containing 3.25×10̂5 microbubbles/ml used for evaluation piece 3 was obtained. Further, by diluting 100% microbubble water with tap water to 20%, a washing liquid containing 2.60×10̂5 microbubbles/ml used for evaluation piece 4 was obtained. Then, by diluting 100% microbubble water with tap water to 12.5%, a washing liquid containing 1.60×10̂5 microbubbles/ml used for evaluation piece 5 was obtained.

Therefore, the cleaning liquids used for evaluation pieces 1 to 5 all have the same number distribution peak and ratio for each particle diameter of microbubbles. That is, in the cleaning liquids used for evaluation pieces 1 to 5, as described above, the maximum peak of the number distribution for each particle size of microbubbles having a particle size of 500 nm or less is within the range of 100 nm±30 nm in particle size. In addition, as described above, the cleaning liquid used for evaluation pieces 1 to 5 had a ratio of 50% or more of the number of microbubbles with a particle diameter of 100 nm ± 30 nm to the number of microbubbles with a particle diameter of 500 nm or less. It's becoming

Here, microbubbles are generally classified as follows according to the particle size of the bubbles. For example, bubbles having a particle diameter of several μm to 50 μm, that is, micro-order bubbles are called microbubbles or fine bubbles. On the other hand, bubbles with a particle size of several hundred nm to several tens of nm or less, that is, nano-order bubbles are called nanobubbles or ultrafine bubbles.

When the particle size of the bubbles is several hundred nm to several tens of nm or less, they become smaller than the wavelength of light and cannot be visually recognized, and the liquid becomes transparent. Nano-order microbubbles have characteristics such as a larger total interfacial area, a slower floating speed, and a higher internal pressure than micro-order or larger bubbles. For example, bubbles with micro-order particle diameters rise rapidly in the liquid due to their buoyancy, burst on the surface of the liquid and disappear, so that the residence time in the liquid is relatively short. On the other hand, microbubbles with a nano-order particle size have a low buoyancy and thus stay in the liquid for a long time.

In the above test, it was found that by including microbubbles in the cleaning liquid in which the surfactant was dissolved, the cleaning performance could be improved compared to cleaning with a normal cleaning liquid that does not contain microbubbles. , which is assumed to be the following principle. That is, as shown in FIG. 9, when the concentration of the surfactant 32 exceeds a certain level, the hydrophobic groups of the surfactant 32 usually gather together to form micelles to form aggregates 33 of the surfactant 32 . The particle diameter of this aggregate 33 is several tens of nm. On the other hand, the microbubbles 31 having a particle diameter of 500 nm or less, for example, have surfaces that are negatively charged and hydrophobic, and thus attract the hydrophobic groups of the surfactant 32 .

Therefore, when a detergent containing aggregates 33 of micellized surfactant 32 is mixed with microbubble water containing microbubbles 31 with a particle diameter of 500 nm or less, the hydrophobic action of the surface of microbubbles 31 causes the energy of aggregates 33 to increase. As shown in FIG. 10, the aggregate 33 collapses and each molecule of the surfactant 32 disperses. Then, each molecule of the dispersed surfactant 32 is adsorbed to the surface of the microbubbles 31 due to the interaction between the hydrophobic group of the surfactant 32 and the hydrophobic surface of the microbubbles 31 . As a result, the surfactant 32 contained in the cleaning liquid is adsorbed by the microbubbles 31 to form a complex 34 .

Then, as shown in FIG. 11, the complex 34 of the surfactant 32 and the microbubbles 31 is diffused over a wide range in the cleaning liquid by the buoyancy of the microbubbles 31 and the like. Therefore, the probability that each molecule of the surfactant 32 comes into contact with, for example, the sebum staining component 36 adhered to the fiber 35 is greatly improved. Then, as shown in FIG. 12, when the complex 34 of the surfactant 32 and the microbubbles 31 approaches the dirt component 36, the hydrophobic action of the surface of the dirt component 36 causes the energy of the surfactant 32 and the microbubbles 31 to increase. The physical stability of the microbubbles 31 is lost, and deformation and bursting of the microbubbles 31 occur. Then, each molecule of the surfactant 32 is separated and adsorbed to the dirt component 36, and the dirt component 36 is lifted from the fiber 35 by the impact caused by the bursting of the microbubbles 31 and easily peeled off.

At this time, the surfactant 32 enters the gap between the dirt components 36 and the fibers 35 caused by the impact of the bursting of the microbubbles 31 , thereby promoting the emulsification of the dirt components 36 . The surfactant 32 takes in and emulsifies the dirt component 36, thereby peeling the dirt component 36 from the fibers 35, thereby exerting the cleaning ability. In this way, the microbubbles 31 are said to bring out the cleaning ability of the surfactant 32 .

The cleaning method of this embodiment can be applied to a washing machine 40 as shown in FIG. 14, for example. The washing machine 40 includes an outer case 41 , a top cover 42 , a water tank 43 , a rotating tub 44 , a pulsator 45 , a motor 46 , a water injection device 50 and a fine bubble generator 10 . The washing machine 40 is a so-called vertical axis type washing machine in which the rotating shaft of the rotating tub 44 is oriented vertically. The washing machine is not limited to the vertical axis type, but may be a horizontal axis type so-called drum type washing machine in which the rotation axis of the rotating tub is horizontal or inclined downward toward the rear.

The water injection device 50 is provided above the outer casing 41 and inside the top cover 42 . The water injection device 50 has a first water supply valve 51 , a second water supply valve 52 , a third water supply valve 53 , a connection port 54 , a water injection case 60 and a fine bubble generator 10 . That is, in washing machine 40 , microbubble generator 10 is incorporated in water injection device 50 as a component of water injection device 50 .

The connection port 54 is connected to a water supply source such as a water faucet via a hose (not shown). The downstream side of the connection port 54 branches into a plurality of branches and is connected to the water injection case 60 via each water supply valve 51 , 52 , 53 . In the case of this embodiment, the downstream side of the connection port 54 is branched into three and connected to the water injection case 60 via respective water supply valves 51 , 52 , 53 .

The water injection case 60 receives water supplied from the connection port 54 and injects the received water from the water injection port 61 into the water tub 43 and the rotary tub 44 . The water injection case 60 has a drawer type detergent case 62 and a softener case 63 . Detergent is put into the detergent case 62 and softener is put into the softener case 63 .

In this configuration, when the first water supply valve 51 is opened, tap water supplied from a faucet (not shown) to the connection port 54 passes through the microbubble generator 10 to become microbubble water containing microbubbles. It is supplied to the detergent case 62 inside the case 60 . The microbubble water supplied into the detergent case 62 through the microbubble generator 10 flows down to the bottom of the water injection case 60, and then is injected from the water injection port 61 into the water tub 43 and the rotary tub 44. At this time, if detergent is stored in the detergent case 62, the detergent is dissolved in the microbubble water supplied in the detergent case 62, and flows down from the water inlet 61 into the water tub 43 and the rotary tub 44. be

Similarly, when the second water supply valve 52 is opened, tap water supplied from a faucet (not shown) to the connection port 54 is supplied to the detergent case 62 inside the water injection case 60 . The tap water supplied into the detergent case 62 flows down to the bottom of the water injection case 60 and then is injected from the water injection port 61 into the water tub 43 and the rotary tub 44 . At this time, if the detergent is stored in the detergent case 62, the detergent is dissolved in the tap water supplied in the detergent case 62 and flowed down from the water inlet 61 into the water tank 43 and the rotary tank 44. .

In this embodiment, by opening the first water supply valve 51, microbubble water is supplied through the microbubble generator 10, and by opening the second water supply valve 52, microbubble water is supplied without passing through the microbubble generator 10. The supplied tap water is mixed in the water injection case 60 or the water tank 43 to become the washing liquid. In this case, the washing machine 40 can adjust the mixing ratio of microbubble water and tap water in the washing liquid by adjusting the opening/closing time and timing of the first water supply valve 51 and the second water supply valve 52. . This makes it possible to arbitrarily adjust the concentration of microbubbles contained in the washing liquid.

Further, when the third water supply valve 53 is opened, tap water supplied from a faucet (not shown) to the connection port 54 is supplied to the softener case 63 inside the water injection case 60 . The tap water supplied into the softener case 63 flows down to the bottom of the water injection case 60 and then is injected from the water injection port 61 into the water tub 43 and the rotary tub 44 . At this time, if softener is stored in the softener case 63 , the softener is dissolved in the tap water supplied to the softener case 63 , and is discharged from the water inlet 61 into the water tank 43 and the rotary tank 44 . washed away. In addition, the fine bubble generator 10 may be further provided on the path of the third water supply valve 53 .

The washing machine 40 agitates the laundry in the rotary tub 44 by driving the motor 46 to rotate the pulsator 45 while the washing liquid is stored in the tub 43 and the rotary tub 44. I do. In this case, not circulating water but tap water is applied to the microbubble generator 10 . That is, in the present embodiment, the microbubble water used in the washing liquid is generated by passing tap water through the microbubble generator 10 once, that is, generated in one pass. In addition, the fine bubble generator 10 may be provided in the middle of the circulation path for circulating the washing liquid in the washing machine 40 . According to this, the concentration of microbubbles in the washing liquid can be further increased by allowing the washing liquid to pass through the microbubble generator 10 a plurality of times.

According to the washing method and the washing machine 40 according to the embodiment described above, microbubble water containing 1×10̂5 or more microbubbles with a particle size of 500 nm or less per 1 ml, a surfactant such as a detergent, The object to be washed is washed with a washing liquid mixed with

According to this, the number and particle size of fine bubbles can be made suitable for cleaning with a surfactant. As a result, the effect of the interaction between the microbubbles and the surfactant can be sufficiently brought out, and as a result, the cleaning efficiency can be improved compared to cleaning with a cleaning liquid that does not contain microbubbles.

Microbubbles have a negative surface charge. It is said that the smaller the particle size of the microbubbles, that is, the smaller the particle size, the greater the negative charge on the surface of the microbubbles. Therefore, the smaller the particle diameter, the easier it is for the microbubbles to adsorb the surfactant, and as a result, the more easily they form aggregates with the surfactant. However, when the particle size of the microbubbles becomes smaller, the surface area of the microbubbles becomes smaller, so the amount of surfactant that can be adsorbed by one microbubble decreases.

On the other hand, in the microbubble water used in the washing method and the washing machine 40 of the present embodiment, the maximum peak of the number distribution for each particle diameter of microbubbles with a particle diameter of 500 nm or less is within the particle diameter range of 100 nm±30 nm. According to this, the adsorption capacity of the surfactant based on the electrical properties of the microbubbles and the adsorption amount of the surfactant based on the size of the microbubbles can be brought into an appropriate state. As a result, the effect of the interaction between the microbubbles and the surfactant can be brought out more effectively.

In the fine bubble water used in the washing method and the washing machine 40 of the present embodiment, the ratio of the number of fine bubbles having a particle diameter of 100 nm±30 nm to the number of fine bubbles having a particle diameter of 500 nm or less is 50% or more. It's becoming This also makes it possible to further optimize the adsorption capacity of the surfactant based on the electrical properties of the microbubbles and the adsorption amount of the surfactant based on the size of the microbubbles. As a result, the effect of the interaction between the microbubbles and the surfactant can be brought out more effectively.

The microbubble water used in the washing method and the washing machine 40 according to the embodiment is generated by passing tap water through the microbubble generator 10 once. According to this, the supply time of fine bubble water can be shortened as compared with the case where tap water is passed through the fine bubble generator 10 a plurality of times to generate fine bubble water. As a result, cleaning time can be shortened.

In addition, the washing method of the above-described embodiment is not limited to the washing machine 40, and can be applied to, for example, a dishwasher and a toilet bowl.
When the washing method of the above embodiment is applied to a dishwasher, the dishwasher uses microbubble water generated through the microbubble generator 10 described above, for example, to wash the dishes to be washed. In this case, the microbubble generator 10 may be provided in the water supply path for supplying tap water from the tap into the dishwasher or in the middle of the circulation path for circulating the water supplied to the dishwasher. As a result, microbubble water containing microbubbles is supplied into the dishwasher through the microbubble generator 10 . By mixing the microbubble water and the dishwashing detergent in the dishwasher, the effect of the interaction between the microbubbles and the surfactant can be effectively brought out as described above.

Further, when the cleaning method of the above embodiment is applied to a toilet bowl, the inside of the toilet bowl to be cleaned is cleaned using microbubble water generated through the microbubble generator 10 described above, for example. In this case, the microbubble generator 10 may be provided in the middle of the water supply path for supplying tap water from the water supply to the toilet bowl. As a result, microbubble water containing microbubbles is supplied into the toilet through the microbubble generator 10 . Then, in the toilet bowl, for example, when the user cleans the inside of the toilet bowl, the detergent put into the toilet bowl and the microbubble water supplied into the toilet bowl are mixed, and as described above, the microbubbles and the surfactant It is possible to effectively draw out the effect of interaction with the agent. In this case, the toilet bowl may be provided with a mechanism for automatically supplying the detergent together with the microbubble water into the toilet bowl.

Although one embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be embodied in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and its equivalents.

In the drawing, 31 denotes fine air bubbles, 32 denotes a surfactant, and 40 denotes a washing machine.

Claims (7)

A washing method for washing laundry, tableware, or a toilet bowl with a washing liquid obtained by mixing microbubble water containing 1×10^5 or more microbubbles with a particle diameter of 500 nm or less per 1 ml and a surfactant. There is
In the microbubble water, the ratio of the number of microbubbles with a particle diameter of 100 nm ± 30 nm to the number of microbubbles with a particle diameter of 500 nm or less is 50% or more.
cleaning method. In the microbubble water, the maximum peak of the number distribution for each diameter of microbubbles with a particle diameter of 500 nm or less is within the range of 100 nm ± 30 nm in particle diameter.
The cleaning method according to claim 1. In the microbubble water, at least two peaks including the maximum peak in the number distribution for each diameter of microbubbles with a particle diameter of 500 nm or less are within the range of 100 nm ± 30 nm in particle diameter.
The cleaning method according to claim 1 or 2 . The fine bubble water is generated by passing tap water through a fine bubble generator once.
The cleaning method according to any one of claims 1 to 3. A washing machine using the washing method according to any one of claims 1 to 4. A dishwasher using the cleaning method according to any one of claims 1 to 4. A toilet using the cleaning method according to any one of claims 1 to 4.

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