Cleaning liquid and method for producing same, cleaning device, and cleaning method

Abstract

This cleaning liquid contains fine bubbles in a solution containing a polyoxyalkylene nonionic surfactant having a cloud point of 30-50°C and an HLB of 10-16, and a polycarboxylic acid and / or a salt thereof.

Description

Cleaning liquid, method for producing the same, cleaning device, and cleaning method

[0001] The present invention relates to a cleaning liquid, a method for producing the same, a cleaning device using the cleaning liquid, and a cleaning method using the cleaning liquid. This application claims priority based on Japanese Patent Application No. 2025-7741 filed in Japan on January 20, 2025, and the content thereof is incorporated herein by reference.

[0002] Conventionally, cleaning agents have been used to remove oil and fat stains and protein stains adhering to objects to be cleaned such as metal parts, plastic products, tableware, and electronic parts by cleaning. As such a cleaning agent, for example, a cleaning agent containing a surfactant is known (for example, Patent Document 1).

[0003] Japanese Patent Laid-Open No. 5-43897

[0004] In automatic cleaning machines such as washer disinfectors (WD), when flowing (for example, circulating or rocking) the cleaning liquid, in order to avoid processing errors caused by bubble generation, the amount of surfactant that can be blended in the cleaning liquid is greatly limited. Also, although various low-foaming surfactants are commercially available, the types of surfactants applicable to automatic cleaning machines are limited. Therefore, currently, the cleaning agents for automatic cleaning machines on the market are formulated with various contrivances, but basically cannot be applied to objects to be cleaned other than the intended use.

[0005] Under such circumstances, there is a demand for a cleaning liquid that not only has strong detergency but is also excellent in low foaming properties. In view of the above problems, an object of the present invention is to provide a cleaning liquid capable of achieving both strong detergency and low foaming properties, a method for producing the same, and a cleaning device and a cleaning method using the cleaning liquid.

[0006] The cleaning liquid according to the present invention has a constitution in which fine bubbles are contained in a solution containing a polyoxyalkylene-based nonionic surfactant having a cloud point of 30 to 50°C and an HLB of 10 to 16, and a polycarboxylic acid and / or its salt. According to this constitution, it is possible to achieve both strong detergency and low foaming properties. More specifically, as this constitution, the solution may further contain at least one of a chelating agent, an alkaline agent, and an antifoaming agent.

[0007] The cleaning device according to the present invention comprises a cleaning tank in which an object to be cleaned is contained, and an FB generator that generates fine bubbles. The device generates a cleaning solution with the above configuration using the generated fine bubbles, and cleans the object to be cleaned by bringing the cleaning solution into contact with the object to be cleaned.

[0008] More specifically, the above configuration may be configured such that the solution circulates in a circulation path passing through the inside of the cleaning tank, and the generated fine bubbles are mixed into the circulating solution. More specifically, the configuration may include a heater for heating the cleaning solution.

[0009] More specifically, the above configuration may include a cleaning nozzle that sprays the cleaning liquid inside the cleaning tank, and the object to be cleaned is cleaned when the sprayed cleaning liquid hits the object to be cleaned. Furthermore, more specifically, the above configuration may include a configuration in which the cleaning liquid is stored inside the cleaning tank, and the object to be cleaned is cleaned when it is immersed in the stored cleaning liquid.

[0010] The present invention relates to a method for generating a cleaning solution, comprising a first step of generating fine bubbles and a second step of mixing the fine bubbles into the solution. The present invention also relates to a cleaning method, comprising a method of cleaning an object to be cleaned by bringing the cleaning solution to the object to be cleaned into contact with the object to be cleaned.

[0011] The cleaning solution according to the present invention makes it possible to achieve both strong cleaning power and low foaming. The production method according to the present invention makes it possible to produce the cleaning solution. Furthermore, the cleaning device and cleaning method according to the present invention make it possible to enjoy the advantages of the cleaning solution.

[0012] This is a schematic diagram of the cleaning device according to the first embodiment. This is a schematic diagram of the cleaning device according to the second embodiment. This is a schematic diagram of the cleaning device according to the third embodiment. This is a schematic diagram of the cleaning device according to the fourth embodiment. This is a schematic diagram of the cleaning device according to the fifth embodiment.

[0013] Embodiments of the present invention will be described below with reference to the drawings.

[0014] 1. Cleaning Solution First, the cleaning solution according to the embodiment of the present invention (hereinafter sometimes referred to as "cleaning solution Z") will be described. In this specification, "cloud point" means the cloud point as defined in JIS K 3211:1990, and refers to the value measured with a 1% by mass aqueous dilution. In this specification, "HLB" is a value that represents the balance between hydrophobicity and hydrophilicity in a surfactant, and refers to the value obtained by the Griffin method using the formula: HLB = 20 × sum of the formula weights of hydrophilic functional groups / molecular weight.

[0015] Cleaning solution Z is a cleaning solution comprising a polyoxyalkylene-based nonionic surfactant with a cloud point of 30 to 50°C and an HLB of 10 to 16, and a polycarboxylic acid and / or its salt, with fine bubbles (bubbles with a diameter of less than 100 μm) included. This solution (hereinafter sometimes referred to as "cleaning agent Q") can also be used as a liquid cleaning agent suitable for automatic cleaning machines even without the fine bubbles. Bubbles with a diameter of 1 μm or more and less than 100 μm are also called "microbubbles," and bubbles with a diameter of less than 1 μm are also called "ultrafine bubbles."

[0016] In the following description, a "polyoxyalkylene-based nonionic surfactant with a cloud point of 30-50°C and an HLB of 10-16" may be referred to as component (a), and a "polycarboxylic acid and / or its salt" (i.e., both or either of the polycarboxylic acid and / or its salt) may be referred to as component (b). Detergent Q can be described as a solution containing component (a) and component (b).

[0017] [Overview of Cleaning Agent Q] Cleaning agent Q, by containing component (a), exhibits strong cleaning power while maintaining low foaming properties. Component (a) may be used alone or in combination of two or more types. The cloud point of component (a) is preferably 30.5 to 47.5°C, more preferably 31 to 45°C, from the viewpoint of achieving both strong cleaning power and low foaming properties. The HLB of component (a) is preferably 11 to 15, more preferably 11.5 to 14, from the viewpoint of achieving both strong cleaning power and low foaming properties.

[0018] (a) The components are not particularly limited, and examples include polyoxyalkylene alkyl ethers represented by the following general formula (1) and alkylene oxide adducts of acetylene glycols represented by the following general formula (2).

[0019]

[0020] In general formula (1), R1 represents an alkyl group, R2 represents an alkylene group, and n represents the average number of repeating alkylene oxide groups for the polyoxyalkylene nonionic surfactant represented by general formula (1) such that the cloud point is 30 to 50°C and the HLB is 10 to 16.

[0021] The alkyl group represented by R1 is not particularly limited; for example, it may be an alkyl group having 6 to 20 carbon atoms, or it may be an alkyl group having 6 to 12 carbon atoms, or an alkyl group having 6 to 8 carbon atoms. The alkylene group represented by R2 is not particularly limited; for example, it may be an alkylene group having 1 to 6 carbon atoms, or it may be an alkylene group having 2 to 4 carbon atoms, or it may be an alkylene group having 2 or 3 carbon atoms. If there are multiple R2s in general formula (1), the R2s may be the same or different from each other.

[0022]

[0023] In general formula (2), R3 to R6 independently represent alkyl groups, R7 and R8 independently represent alkylene groups, and m and n represent the average number of repeating alkylene oxide groups for the polyoxyalkylene nonionic surfactant represented by general formula (2) such that the cloud point is 30 to 50°C and the HLB is 10 to 16.

[0024] The alkyl group represented by R3 and the alkyl group represented by R5 are not particularly limited, and examples include alkyl groups having 1 to 20 carbon atoms, preferably alkyl groups having 2 to 6 carbon atoms, and more preferably alkyl groups having 3 to 5 carbon atoms. The alkyl group represented by R4 and the alkyl group represented by R6 are not particularly limited, and examples include alkyl groups having 1 to 6 carbon atoms, preferably alkyl groups having 1 to 3 carbon atoms, and more preferably alkyl groups having 1 or 2 carbon atoms. The alkylene group represented by R7 and the alkylene group represented by R8 are not particularly limited, and examples include alkylene groups having 1 to 6 carbon atoms, preferably alkylene groups having 2 to 4 carbon atoms, and more preferably alkylene groups having 2 or 3 carbon atoms. When there are multiple R7s in general formula (2), the R7s may be the same or different from each other. Similarly, when there are multiple R8s in general formula (2), the R8s may be the same or different from each other.

[0025] The polyoxyalkylene-based nonionic surfactant represented by general formula (2), having a cloud point of 30 to 50°C and an HLB of 10 to 16, is not particularly limited, and examples include the ethylene oxide adduct of 2,4,7,9-tetramethyl-5-decine-4,7-diol represented by the following general formula (20).

[0026]

[0027] In general formula (20), m and n are numbers from 1 to 8 that independently represent the average number of repeating ethylene oxide groups, and the sum of m and n is in the range of 2 to 16.

[0028] (a) Specific examples of the components are not limited to Acetylenel® E100 (manufactured by Kawaken Fine Chemicals Co., Ltd.; a polyoxyalkylene nonionic surfactant represented by general formula (20) (where m + n = 10), with a cloud point of 45°C and an HLB of 13 to 14) and Sedran FF-180 (manufactured by Sanyo Chemical Industries, Ltd.; a polyoxyalkylene nonionic surfactant represented by general formula (1), with a cloud point of 31°C and an HLB of 11.7).

[0029] The content of component (a) relative to the total amount of detergent Q is preferably 0.1 to 1% by mass, more preferably 0.2 to 0.7% by mass, and even more preferably 0.25 to 0.5% by mass. When the content of component (a) is within the above range, it is easier to achieve both strong cleaning power and low foaming properties.

[0030] In the detergent Q, component (b) (polycarboxylic acid and / or its salt) described above functions as a dispersant. Component (b) may be used alone or in combination of two or more types.

[0031] (b) The polycarboxylic acid of component (b) is not particularly limited and includes, for example, polyacrylic acid, polymethacrylic acid, and polymaleic acid, with polyacrylic acid being preferred from the viewpoint of achieving both strong cleaning power and low foaming properties. The salt of component (b) is not particularly limited and includes, for example, alkali metal salts such as lithium salt, sodium salt, and potassium salt, with sodium salt being preferred from the viewpoint of ease of synthesis or availability.

[0032] (b) Specific examples of components are not limited to, but include Poise 530 (manufactured by Kao Corporation, sodium polyacrylate) and Carribon L-400 (manufactured by Sanyo Chemical Industries, Ltd.; sodium polyacrylate).

[0033] The content of component (b) relative to the total amount of detergent Q is preferably 0.01 to 1% by mass, more preferably 0.03 to 0.5% by mass, and even more preferably 0.05 to 0.3% by mass. When the content of component (b) is within the above range, it is easier to achieve both strong cleaning power and low foaming properties.

[0034] [Chelating Agent] Detergent Q may contain a chelating agent to better achieve both strong cleaning power and low foaming properties. The chelating agent may be used alone or in combination of two or more types.

[0035] The chelating agent is not particularly limited and includes, for example, ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), trans-1,2-diaminocyclohexanetetraacetic acid (CyDTA), diethylenetriaminepentaacetic acid (DTPA), triethylenetetraaminehexaacetic acid (TTHA), glycol etherdiaminetetraacetic acid (GEDTA), hydroxyethylidenediphosphonic acid (HEDP), aminotrimethylenephosphonic acid (ATMP), ethylenediamine Examples include tetramethylenephosphonic acid (EDTMP), phosphonovobutanetricarboxylic acid (PBTC), citric acid, gluconic acid, succinic acid, oxalic acid, phthalic acid, malic acid, tartaric acid, and salts thereof (e.g., alkali metal salts such as lithium salts, sodium salts, and potassium salts; alkanolamine salts such as monoethanolamine salts, diethanolamine salts, and triethanolamine salts; and ammonium salts). Disodium ethylenediaminetetraacetate is preferred because it allows for a better balance between strong cleaning power and low foaming properties.

[0036] The chelating agent content relative to the total detergent Q is preferably 0.0001 to 0.01% by mass, more preferably 0.0003 to 0.007% by mass, and even more preferably 0.0004 to 0.005% by mass. When the chelating agent content is within the above range, it is easier to achieve both strong cleaning power and low foaming properties.

[0037] [Alkaline Agent] Cleaning agent Q may contain an alkaline agent to better achieve both strong cleaning power and low foaming properties. The alkaline agent may be used alone or in combination of two or more types.

[0038] The alkaline agent is not particularly limited and includes, for example, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, and dimethylethanolamine; and alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate. Sodium hydroxide and potassium hydroxide are preferred because they allow for a better balance between strong cleaning power and low foaming.

[0039] With respect to the whole of the cleaning agent Q, the content of the alkaline agent is preferably 0.001 to 0.1% by mass, more preferably 0.0014 to 0.05% by mass, and still more preferably 0.0016 to 0.02% by mass. When the content of the alkaline agent is within the above range, strong detergency and low foaming property are more likely to be compatible.

[0040] [Defoaming agent] The cleaning agent Q may contain a defoaming agent so that strong detergency and low foaming property are more likely to be compatible. The defoaming agent may be used alone or in combination of two or more.

[0041] The defoaming agent is not particularly limited. For example, polyoxyalkylene alkyl ethers with an HLB of 3 to 6 can be mentioned. Since strong detergency and low foaming property are more likely to be compatible, polyoxyalkylene alkyl ethers with an HLB of 4 to 5 are preferred.

[0042] Specific examples of the defoaming agent are not particularly limited, and Nipponpol LB-285 (manufactured by Sanyo Chemical Industries, Ltd., polyoxyalkylene alkyl ether with an HLB of 4.6) can be mentioned.

[0043] With respect to the whole of the cleaning agent Q, the content of the defoaming agent is preferably 0.01 to 1% by mass, more preferably 0.03 to 0.5% by mass, and still more preferably 0.05 to 0.3% by mass. When the content of the defoaming agent is within the above range, strong detergency and low foaming property are more likely to be compatible.

[0044] [Other components] The cleaning agent Q may contain rust inhibitors such as sodium silicate and potassium silicate; pH adjusters such as hydrochloric acid; bactericides such as sodium hypochlorite and hypobromous acid; solvents such as water, etc., within a range that does not impair its effects.

[0045] [Manufacturing method of cleaning agent Q] The cleaning agent Q can be manufactured by mixing component (a), component (b), optionally a chelating agent, optionally an alkaline agent, optionally a defoaming agent, and optionally other components. By adjusting the amounts of each component or adding a pH adjuster, the pH of the cleaning agent Q can be adjusted. The pH of the cleaning agent Q is not particularly limited, and for example, 7.0 to 11.5 can be mentioned, and it is appropriately adjusted according to the dirt to be cleaned.

[0046] [Specific Examples of Detergent Q] Specific examples of detergent Q include Examples 1 to 4, which can be obtained by mixing the components shown in Table 1 below in the ratios (mass %) shown in Table 1. The details of the components described in Table 1 are as follows. (a) Components - a-1: Acetylenol E100 (manufactured by Kawaken Fine Chemical Co., Ltd.; a polyoxyalkylene nonionic surfactant represented by the general formula (20) (where m + n = 10), cloud point 45°C and HLB 13-14) - a-2: Cedran FF-180 (manufactured by Sanyo Chemical Industries, Ltd.; a polyoxyalkylene nonionic surfactant represented by the general formula (1), cloud point 31°C and HLB 11.7) (b) Components - b-1: Poids 530 (manufactured by Kao Corporation, sodium polyacrylate) Chelating agent - c-1: Disodium ethylenediaminetetraacetate Alkaline agent - d-1: Sodium hydroxide - d-2: Potassium hydroxide Antifoaming agent - e-1: Newpol LB-285 (manufactured by Sanyo Chemical Industries, Ltd., polyoxyalkylene alkyl ether with HLB 4.6) Rust inhibitor - f-1: Sodium silicate pH adjuster - g-1: 5M hydrochloric acid

[0047]

[0048] The detergent Q of Example 1 is a strongly alkaline detergent (pH 11.5) based on Acetylenol E100. According to the detergent Q of Example 1, it has been confirmed that it shows strong detergency under both conditions of 50°C and 80°C against any of the stains containing pigments, stains containing silicone-based water repellents, and stains containing proteins.

[0049] The detergent Q of Example 2 is a neutral detergent (pH 7.0) based on Cedran FF-180. According to the detergent Q of Example 2, it has been confirmed that it shows strong detergency at 50°C against stains containing pigments, and shows strong detergency under both conditions of 50°C and 80°C against stains containing silicone-based water repellents.

[0050] The cleaning agent Q in Example 3 is a weakly alkaline cleaning agent (pH 10.4) based on Cedran FF-180. It has been confirmed that the cleaning agent Q in Example 3 exhibits strong cleaning power against both pigment-containing stains and silicone-based water-repellent stains at both 50°C and 80°C conditions, and exhibits strong cleaning power against protein-containing stains at 50°C.

[0051] The cleaning agent Q in Example 4 is a strongly alkaline cleaning agent (pH 11.2) based on Cedran FF-180. It has been confirmed that the cleaning agent Q in Example 4 exhibits strong cleaning power at both 50°C and 80°C conditions against stains containing pigments, stains containing silicone-based water repellents, and stains containing proteins.

[0052] The cloud point is a physical property specific to aqueous solutions of nonionic surfactants with ethylene oxide added as a hydrophilic group, and is a measure of hydrophilicity in nonionic surfactants. Generally, nonionic surfactants with higher hydrophilicity have higher cloud points. At temperatures above the cloud point, the aqueous solution undergoes phase separation and sufficient cleaning power cannot be obtained; therefore, temperatures around the cloud point are generally considered to provide the highest cleaning effect. The cloud point also decreases when salts or alkalis are added. Although the cleaning agent Q of Examples 1 to 4 has a cloud point in the range of 30 to 50°C for component (a), excellent cleaning power can be obtained even when cleaning operations are performed at temperatures above the cloud point.

[0053] [Overview of Cleaning Solution Z] As mentioned above, the cleaning solution Z of this embodiment is a cleaning solution in which fine bubbles are contained in the cleaning agent Q. The fine bubbles in the cleaning solution have the property of reducing the surface tension of water, efficiently penetrating even into narrow gaps, and efficiently removing dirt components through the peeling function of surface adherents based on impact pressure action, as well as hydrophobic interactions and charged adsorption. Furthermore, in the presence of a surfactant, the effect of the surfactant is enhanced as the fine bubbles encapsulated by the surfactant penetrate deep into the object to be cleaned and into the gaps between the dirt components and the attached surface. With a cleaning solution Z containing such fine bubbles in the cleaning agent Q, it is possible to exhibit even stronger cleaning power due to the action of the fine bubbles while retaining the excellent characteristics of the cleaning agent Q.

[0054] The cleaning solution Z is produced by a method that includes, for example, a step of generating fine bubbles (first step) and a step of mixing the fine bubbles with the cleaning agent Q (second step). However, the method of producing the cleaning solution Z is not limited to this, and as an example, fine bubbles may be mixed with the solvent (water, etc.) of the cleaning agent Q, and then the components of the cleaning agent Q may be further mixed into this mixed solvent to produce the cleaning solution Z. Furthermore, the cleaning solution Z can be used to clean an object by bringing it into contact with the object to be cleaned, such as in the shower cleaning operation or immersion cleaning operation performed in the cleaning device described later.

[0055] 2. Washing Device Next, the washing devices according to the embodiments of the present invention will be described below, with reference to the first to fifth embodiments. The washing device of each embodiment is configured to generate a cleaning solution Z using fine bubbles generated by an FB generator, and to clean the object to be cleaned by bringing this cleaning solution Z into contact with it.

[0056] 2-1. First Embodiment [Configuration of Washer, etc.] Figure 1 is a schematic configuration diagram showing the washer M1 of the first embodiment, with a portion shown in cross-section. For the sake of explanation, the left-right direction in Figure 1 will be considered the left-right direction of the washer M1, the up-down direction in Figure 1 will be considered the up-down direction of the washer M1, and the direction perpendicular to the plane of the paper in Figure 1 will be considered the front-to-back direction of the washer M1 (the front side is the front). In Figure 1, the dashed line shows the outer shape of the washing rack 2 and the shelf 3.

[0057] The cleaning device M1 can be used as a washer-disinfector (WD) and comprises a cleaning tank 4 that forms a cleaning space for the object to be cleaned, a liquid storage section 5 connected to the lower part of the cleaning tank 4, a cleaning rack 2 on which the object to be cleaned is placed and moved in and out of the cleaning tank 4, cleaning nozzles 6 provided on the cleaning tank 4 and the cleaning rack 2, a water supply means 7 to the liquid storage section 5, a drainage means 8 from the liquid storage section 5, a chemical supply means 9 to the liquid storage section 5, a heating means 10 for heating the liquid L in the liquid storage section 5, a circulation means 11 for supplying the liquid L from the liquid storage section 5 to the cleaning nozzles 6, and control means (not shown) for controlling each part of the cleaning device M1, including these means 7 to 11.

[0058] The items to be cleaned are not particularly limited, but may include medical instruments such as forceps, as well as containers and utensils contaminated with food or cosmetics. When the cleaning rack 2 is stored in the cleaning tank 4, cleaning nozzles 6 are provided in multiple levels, both above and below, within the cleaning tank 4, and the items to be cleaned are placed between the upper and lower cleaning nozzles 6. The items to be cleaned are placed on the shelves 3 of the cleaning rack 2, and the entire cleaning rack 2 is moved in and out of the cleaning tank 4. At that time, the items to be cleaned may be placed in baskets or the like, if desired.

[0059] In this embodiment, the cleaning tank 4 is a roughly rectangular hollow box. The cleaning tank 4 is made openable and closable by a door (not shown). By opening the door, the cleaning rack 2 can be inserted into and removed from the cleaning tank 4. The door is provided on the front of the cleaning tank 4, but it may also be provided on both the front and back of the cleaning tank 4.

[0060] A liquid storage section 5 is connected to the lower part of the cleaning tank 4. In other words, the cleaning tank 4 is equipped with a liquid storage section 5 at its lower part. In this embodiment, the lower wall of the cleaning tank 4 is formed as an inclined surface 12 at both the left and right ends, which slope downward as they move inward in the left-right direction, and the central part in the left-right direction is formed as a roughly rectangular recess downward, and the lower part of the cleaning tank 4, including this recess, is the liquid storage section 5.

[0061] The washing rack 2 comprises shelves 3 on which objects to be washed are placed, and washing nozzles 6 positioned below the shelves 3. In the illustrated example, the washing rack 2 has multiple shelves 3 arranged vertically, with washing nozzles 6 provided below each shelf 3. Each shelf 3 is formed by combining wires. As will be described in detail later, a water distribution member 13 is provided at one end of the washing rack 2, and the washing nozzles 6 are rotatably held by the water distribution member 13 via a washing arm 14.

[0062] In the storage position where the cleaning rack 2 is pushed to a predetermined position within the cleaning tank 4, the water passage duct 15 provided on the inner wall of the cleaning tank 4 and the water distribution member 13 provided on the cleaning rack 2 are connected, allowing liquid L to be supplied from the water passage duct 15 to the water distribution member 13.

[0063] The cleaning nozzle 6 sprays liquid L onto the object to be cleaned. When the cleaning rack 2 is stored inside the cleaning tank 4, the cleaning nozzles 6 are provided in multiple vertical rows inside the cleaning tank 4 via cleaning arms 14. In this embodiment, as shown in Figure 1, the cleaning nozzles 6 provided at both the upper and lower ends inside the cleaning tank 4 are provided on the cleaning tank 4 itself via cleaning arms 14, while the other cleaning nozzles 6 are provided on the cleaning rack 2 via cleaning arms 14. More specifically, regarding the holding of the cleaning nozzles 6 when the cleaning rack 2 is stored inside the cleaning tank 4, the base ends of multiple vertical rows of hollow pipe-shaped cleaning arms 14 are held on one side (the left side in Figure 1) of the central part in the front-to-back direction of the cleaning tank 4 (or cleaning rack 2), and each cleaning arm 14 extends from one side of the cleaning tank 4 toward the central part in the left-to-right direction. The longitudinal center of the cleaning nozzle 6 is held at the tip of the extended arm so as to be rotatable around a vertical axis.

[0064] The cleaning nozzle 6 has multiple nozzle holes 16 formed therein, which eject the liquid L supplied through the cleaning arm 14. When liquid L is supplied to the cleaning nozzle 6 via the cleaning arm 14, the liquid L is ejected from the nozzle holes 16 of the cleaning nozzle 6. This jet causes the cleaning nozzle 6 to rotate around the end of the cleaning arm 14. The cleaning nozzle 6 located at the upper end of the cleaning tank 4 ejects liquid L only downwards, the cleaning nozzle 6 located at the lower end of the cleaning tank 4 ejects liquid L only upwards, and the cleaning nozzles 6 other than those at both the upper and lower ends eject liquid L in both directions. The cleaning arm 14 and the cleaning nozzle 6 are made of metal, such as stainless steel.

[0065] The water supply means 7 supplies water to the liquid storage section 5 (and optionally to the washing tank 4) via a water supply channel 17. The water supply channel 17 is equipped with a water supply valve 18 and a flow sensor 87. By opening the water supply valve 18, water can be supplied to the liquid storage section 5. The water supply means 7 may be configured to supply water selected from multiple types of water (for example, tap water, hot water, membrane filtered water, etc.).

[0066] The cleaning tank 4 is equipped with a liquid level detector 19. The liquid level detector 19 does not have any particular configuration, but for example, it is composed of a pressure sensor installed at the bottom of the liquid storage section 5. In this case, the liquid level is determined by utilizing the fact that the water pressure changes according to the liquid level in the liquid storage section 5 and the cleaning tank 4.

[0067] The drainage means 8 discharges water from the liquid storage section 5 through the drainage channel 20. The drainage channel 20 is equipped with a drain valve 21. By opening the drain valve 21, water can be drained from the washing tank 4 and the liquid storage section 5.

[0068] The chemical supply means 9 supplies the chemical solution from the chemical solution tank 22 to the liquid storage section 5 (or cleaning tank 4) via the liquid supply passage 23. A chemical solution pump 24 is provided in the liquid supply passage 23. By operating the chemical solution pump 24, a set amount of chemical solution can be supplied to the liquid storage section 5. The chemical solution contains the components of the cleaning agent Q described above, and contains at least components (a) and (b), and may further contain at least one of the chelating agent, alkaline agent, and defoaming agent described above. The cleaning agent Q is generated when the chemical solution is mixed with water supplied by the water supply means 7.

[0069] The heating means 10 heats the stored liquid (liquid L) in the liquid storage section 5. In this embodiment, the heating means 10 consists of a heater 25 provided in the liquid storage section 5. In the illustrated example, the heater 25 is an electric heater, but it may be a steam heater depending on the circumstances. In the case of an electric heater, it is typically controlled on and off, but the output may be adjusted depending on the circumstances. On the other hand, in the case of a steam heater, steam can be supplied into the steam pipe, and the condensed water of the steam is discharged to the outside via a steam trap. The opening and closing or degree of opening of the steam supply valve provided in the steam supply passage is controlled.

[0070] A temperature sensor 26 is provided in the liquid storage section 5. The temperature of the liquid stored in the liquid storage section 5 can be adjusted by controlling the heater 25 based on the temperature detected by the temperature sensor 26. When cleaning liquid Z (or cleaning agent Q) is stored in the liquid storage section 5, it is preferable that the temperature of the cleaning liquid Z (or cleaning agent Q) is adjusted by controlling the heater 25 so as to maximize the cleaning power.

[0071] The circulation means 11 circulates the liquid L in the liquid storage section 5. Specifically, the circulation means 11 includes a circulation pipe 27, a circulation pump 28, a shower valve 81, an immersion cleaning line 85, and an immersion cleaning valve 86. The circulation pipe 27 is the piping from the liquid storage section 5 to the cleaning arms 14 of each cleaning nozzle 6, and includes the aforementioned water passage duct 15. The circulation pump 28 is located upstream of the water passage duct 15 in the circulation pipe 27, and a check valve 29 is provided on the outlet side of the circulation pump 28.

[0072] A shower valve 81 is provided downstream of the check valve 29 in the circulation piping 27, which allows switching between opening and closing (conductive / non-conductive) the circulation piping 27. Between the check valve 29 and the shower valve 81 in the circulation piping 27, an immersion cleaning line 85 is connected, which communicates with the inside of the cleaning tank 4 (at the location of the inclined surface 12 in the example of Figure 1). An immersion cleaning valve 86 is provided midway along the immersion cleaning line 85, which allows switching between opening and closing (conductive / non-conductive) the immersion cleaning line 85.

[0073] When the shower valve 81 is in a conductive state and the circulation pump 28 is activated, the liquid L in the liquid reservoir 5 is supplied to the cleaning nozzle 6 via the circulation piping 27 (including the water passage duct 15), the water distribution member 13, and the cleaning arm 14, and is sprayed from the cleaning nozzle 6. The liquid L sprayed from the cleaning nozzle 6 is returned to the liquid reservoir 5 at the bottom of the cleaning tank 4. On the other hand, when the immersion cleaning valve 86 is in a conductive state and the circulation pump 28 is activated, the liquid L in the liquid reservoir 5 is returned to the cleaning tank 4 via the circulation piping 27 and the immersion cleaning line 85.

[0074] Furthermore, the cleaning device M1 is equipped with a shower cleaning float sensor 82, an immersion cleaning float sensor 83, and a temperature sensor 84. The shower cleaning float sensor 82 has the function of detecting liquid L overflow when the shower cleaning operation described later is performed. The immersion cleaning float sensor 83 has the function of detecting liquid L overflow when the immersion cleaning operation described later is performed. The temperature sensor 84 measures the temperature of the cleaning liquid Z sprayed during the shower cleaning operation (the temperature of the cleaning liquid Z that comes into contact with the object to be cleaned). If an overflow is detected by these sensors 82 and 83, or if an abnormal temperature is measured by the temperature sensor 84, the device may be configured to notify the user or to stop the cleaning operation.

[0075] An FB generator X1 is provided in the circulation piping 27 between the circulation pump 28 and the check valve 29. Furthermore, an FB airline 110, an air supply means 111, an air control valve 112, and an air check valve 113 are provided as elements that are highly related to the FB generator X1.

[0076] The FB Airline 110 has its upstream end connected to the air supply means 111 and its downstream end connected to a position in the circulation piping 27 between the circulation pump 28 and the FB generator X1. The air supply means 111 supplies air to the FB Airline 110 for generating fine bubbles in the FB generator X1. In this embodiment, the air supply means 111 is a relatively high-pressure pressurized air supply device such as an air compressor or an air cylinder. The FB Airline 110 is provided with an air control valve 112 and an air check valve 113, in that order from the air supply means 111 side. The air control valve 112 allows adjustment of the flow rate or pressure of the air passing through the FB Airline 110. The air check valve 113 prevents backflow of air passing through the FB Airline 110.

[0077] The FB generator X1 generates fine bubbles using pressurized air supplied from the FB airline 110 to the circulation pipe 27. In this embodiment, the FB generator X1 has a configuration in which multiple columnar bodies, each having multiple protrusions extending from the inner surface of the cylinder toward the center, are arranged axially inside an outer cylinder that communicates with the circulation pipe 27. The multiple protrusions provided on each of the multiple columnar bodies agitate the liquid L flowing through the circulation pipe 27 while mixed with the pressurized air, causing the gas and liquid to collide violently and generate cavitation, thereby generating a swirling flow and fine bubbles. As a result, fine bubbles can be mixed into the liquid L flowing through the circulation pipe 27 without causing excessive pressure loss.

[0078] The control means in the cleaning device M1 is configured, for example, as controllers (not shown) connected to various parts of the cleaning device M1. The control means executes operations such as cleaning the objects to be cleaned in the cleaning tank 4 according to a predetermined procedure (program). In the cleaning device M1 of this embodiment, at least shower cleaning and immersion cleaning operations can be performed. These operations will be described in order below.

[0079] [Shower Cleaning Operation] The shower cleaning operation involves storing liquid L in the liquid reservoir 5, circulating the liquid L to the cleaning nozzle 6 via the circulation means 11, and spraying it onto the object to be cleaned from the cleaning nozzle 6. The object to be cleaned is placed on the shelf 3 of the cleaning rack 2 in advance, and the shower cleaning operation is performed.

[0080] When the shower cleaning operation is started, the shower valve 81 is opened and the immersion cleaning valve 86 is de-opened, and the water supply valve 18 is opened to supply water to the liquid storage section 5. When the flow sensor 87 detects that a predetermined set amount of water has been supplied and the liquid level detector 19 detects that the liquid level has exceeded a predetermined set level, the water supply valve 18 is closed.

[0081] When the circulation pump 28 is activated with the desired amount of water stored in the liquid storage section 5, the stored water flows through the circulation pipe 27 toward the cleaning arm 14. Simultaneously, the heating means 10 heats the stored water to a set temperature (for example, a temperature near the cloud point of component (a)). Once the circulating stored water is heated to the set temperature, the chemical supply means 9 introduces the chemical solution into the liquid storage section 5. The chemical supply means 9 introduces a set amount of chemical solution relative to the amount of water supplied by the water supply means 7, so that the concentration reaches a set level (a concentration at which the cleaning agent Q is appropriately generated). As a result, the chemical solution mixes with the water in the liquid storage section 5, generating the cleaning agent Q as liquid L, which then flows through the circulation pipe 27.

[0082] After the detergent Q is generated, the air supply means 111 is activated and the FB generator X1 generates fine bubbles. The operation of the circulation pump 28 and the air supply means 111 continues until a predetermined termination condition (for example, the elapsed of a set time) is met. The air control valve 112 is appropriately controlled so that a desired amount of fine bubbles are generated.

[0083] The fine bubbles generated by the FB generator X1 are mixed with the cleaning agent Q flowing through the circulation pipe 27. This generates a cleaning solution Z as a liquid L, which is supplied to the cleaning nozzle 6 via the cleaning arm 14 and sprayed from the rotating cleaning nozzle 6. The object to be cleaned is cleaned when this sprayed liquid L (cleaning solution Z) comes into contact with it (the cleaning solution Z comes into contact with the object to be cleaned).

[0084] The liquid L sprayed from each cleaning nozzle 6 is returned to the liquid storage section 5 at the bottom of the cleaning tank 4. The liquid L returned to the liquid storage section 5 flows again through the circulation pipe 27 due to the operation of the circulation pump 28. At this time, fine bubbles generated by the FB generator X1 are further mixed into the liquid L flowing again through the circulation pipe 27. In this way, the liquid L circulates repeatedly, increasing the number of fine bubbles mixed in and enhancing the cleaning performance of the cleaning liquid Z.

[0085] When the termination conditions described above are met, the operation of the circulation pump 28 and the air supply means 111 is stopped. Subsequently, the drain valve 21 is opened until the liquid level is no longer detected by the liquid level detector 19, and the shower cleaning operation ends. The shower cleaning operation may be performed only once or repeatedly over multiple cycles.

[0086] [Immersion Cleaning Operation] The immersion cleaning operation involves storing liquid L in the cleaning tank 4 and cleaning the object to be cleaned by immersing it in the liquid L. The object to be cleaned is placed in advance in a position to be immersed in the liquid L in the cleaning tank 4 (for example, the bottom shelf 3 of the cleaning rack 2), and the immersion cleaning operation is performed.

[0087] When the immersion cleaning operation is started, the shower valve 81 is deactivated and the immersion cleaning valve 86 is activated, and water is supplied to the cleaning tank 4 by the water supply means 7 until the liquid level detector 19 detects a predetermined set water level (a water level at which the objects to be cleaned can be reliably immersed). Later, when the circulation pump 28 is activated, the water level will drop, so this point is also taken into consideration when determining the set water level so that the objects to be cleaned can be reliably immersed.

[0088] When the circulation pump 28 is activated with the desired amount of water stored in the liquid storage section 5, the stored water flows through the circulation pipe 27 toward the immersion cleaning line 85. Simultaneously, the heating means 10 heats the stored water to a set temperature (for example, a temperature near the cloud point of component (a)). Once the stored water has reached the set temperature, the chemical supply means 9 introduces the chemical solution into the liquid storage section 5. The chemical supply means 9 introduces a set amount of chemical solution relative to the amount of water supplied by the water supply means 7 so that the concentration reaches a set level (a concentration at which the cleaning agent Q is appropriately generated). As a result, the chemical solution mixes with the water in the liquid storage section 5, generating the cleaning agent Q as liquid L, which then flows through the circulation pipe 27.

[0089] After the detergent Q is generated, the air supply means 111 is activated and the FB generator X1 generates fine bubbles. The operation of the circulation pump 28 and the air supply means 111 continues until a predetermined termination condition (for example, the elapsed of a set time) is met. The air control valve 112 is appropriately controlled so that a desired amount of fine bubbles are generated.

[0090] The fine bubbles generated by the FB generator X1 are mixed with the liquid L flowing through the circulation pipe 27. This generates a cleaning solution Z as liquid L, which is then returned to the cleaning tank 4 via the immersion cleaning line 85. In this way, the objects to be cleaned are immersed in the liquid L (cleaning solution Z) (the objects to be cleaned are in contact with the cleaning solution Z) within the cleaning tank 4, and the objects are cleaned.

[0091] Furthermore, the liquid L returned to the cleaning tank 4 flows again through the circulation pipe 27 due to the operation of the circulation pump 28. At this time, fine bubbles generated by the FB generator X1 are further mixed into the liquid L flowing again through the circulation pipe 27. In this way, the liquid L circulates repeatedly, increasing the number of fine bubbles mixed in and enhancing the cleaning performance of the cleaning solution Z. Moreover, because the liquid L in which the object to be cleaned is immersed flows due to this circulation, a higher cleaning effect can be obtained compared to when the liquid L is stationary.

[0092] When the above-mentioned termination conditions are met, the operation of the circulation pump 28 and the air supply means 111 is stopped. Subsequently, the liquid L in the cleaning tank 4 is discharged by the drainage means 8, and the immersion cleaning operation is completed. The immersion cleaning operation may be performed only once, or it may be performed repeatedly over multiple cycles.

[0093] [Other] As described above, the shower cleaning operation and immersion cleaning operation have been explained, but the cleaning device M1 can also perform a rinsing operation. This rinsing operation is basically the same as the shower cleaning operation or immersion cleaning operation, except that the supply of chemical solution by the chemical solution supply means 9 is omitted. With this rinsing operation, after performing the shower cleaning operation or immersion cleaning operation, it is possible to effectively remove the cleaning solution Z adhering to the object to be cleaned using water (rinsing water) mixed with fine bubbles as liquid L, and it is possible to shorten the time and number of rinsing operations compared to conventional methods.

[0094] The applicant also conducted a test to confirm the cleaning effect of cleaning solution Z (particularly its cleaning effect against oily stains in the neutral range) using the cleaning device M1. More specifically, a stainless steel plate, whose entire surface had been colored with an oily marker and dried, was used as the object to be cleaned, and the removal of the oily marker was observed over time during an immersion cleaning operation. In the cleaning device M1, the cleaning agent Q was configured to be a neutral cleaning agent containing 0.5% by mass of Cedran FF-180 and 0.3% by mass of Poise 530, and fine bubbles were mixed with this to generate a neutral cleaning solution Z. As a result, the oily marker was removed well, and the excellent cleaning effect of cleaning solution Z against oily stains in the neutral range was confirmed. In particular, a very high cleaning effect was obtained when the number of fine bubbles contained in cleaning solution Z was sufficiently increased, and then physical action by circulating cleaning solution Z was added. Thus, cleaning solution Z provides excellent cleaning effects even against oily stains that are generally difficult to remove with cleaning agents alone, and in particular, if a neutral cleaning solution Z is used, neutralization treatment of the cleaning wastewater becomes unnecessary.

[0095] 2-2. Second Embodiment Next, the cleaning device M2 of the second embodiment will be described. In the description of the second embodiment, emphasis will be placed on explaining the differences from the first embodiment, and explanations of matters common to the first embodiment may be omitted.

[0096] Figure 2 is a schematic diagram showing the configuration of the cleaning device M2 of the second embodiment. As shown in this figure, the cleaning device M2 is equipped with an FB generator X2, an FB air line 120, an FB bypass line 121, an air supply means 122, an air control valve 123, an air check valve 124, and an FB control valve 125, instead of the FB generator X1 and the elements 110 to 113 (see Figure 1) that are closely related to it in the first embodiment.

[0097] The FB bypass line 121 has its upstream end connected between the circulation pump 28 and the check valve 29 in the circulation piping 27, and its downstream end connected between the connection point of the upstream end and the check valve 29 in the circulation piping 27. The FB bypass line 121 is equipped with an FB control valve 125 and an FB generator X2 in that order from the upstream side. The FB bypass line 121 can bypass all or part of the liquid L passing through the circulation piping 27 to return it through the FB generator X2. The FB control valve 125 can adjust the flow rate or pressure of the liquid L passing through the FB bypass line 121.

[0098] The FB Airline 120 has its upstream end connected to the air supply means 122 and its downstream end connected to the FB generator X2. The air supply means 122 supplies air to the FB Airline 120 for generating fine bubbles in the FB generator X2. In this embodiment, the air supply means 122 is a relatively high-pressure pressurized air supply device such as an air compressor or an air cylinder. The FB Airline 120 is provided with an air control valve 123 and an air check valve 124, in that order from the air supply means 122 side. The air control valve 123 allows adjustment of the flow rate or pressure of the air passing through the FB Airline 120. The air check valve 124 prevents backflow of air passing through the FB Airline 120.

[0099] The FB generator X2 generates fine bubbles using pressurized air supplied from the FB airline 120. In this embodiment, the FB generator X2 has a porous ceramic tube and generates fine bubbles by blowing out the pressurized air from micro- and nano-sized pores. That is, pressurized air is continuously injected through the pores in the tube wall while the liquid L is internally perfusated through the porous ceramic tube that communicates with the FB bypass line 121. This makes it possible to mix fine bubbles into the liquid L flowing through the circulation piping 27 without causing excessive pressure loss.

[0100] When a shower cleaning operation or immersion cleaning operation is performed in the cleaning device M2, the air supply means 122 operates instead of the air supply means 111 in the first embodiment. Also, the air control valve 123 is appropriately controlled instead of the air control valve 112 in the first embodiment. Furthermore, the FB control valve 125 is appropriately controlled so that a desired amount of liquid L is supplied to the FB generator X2.

[0101] As a result, the fine bubbles generated by the FB generator X2 are mixed with the liquid L that flows from the circulation pipe 27 into the FB bypass line 121, and this mixed liquid L is returned to the circulation pipe 27. In this way, as in the first embodiment, cleaning liquid Z is generated as liquid L, and further, fine bubbles are mixed into the liquid L that flows again through the FB bypass line 121. Therefore, as the circulation of liquid L is repeated, the number of fine bubbles mixed increases, and the cleaning performance of cleaning liquid Z is enhanced.

[0102] Furthermore, when a rinsing operation is performed in the cleaning device M2, the air supply means 122 operates instead of the air supply means 111 in the first embodiment, and fine bubbles are generated by the FB generator X2. This makes it possible to effectively remove the cleaning solution Z adhering to the object to be cleaned using water (rinsing water) mixed with fine bubbles as liquid L.

[0103] 2-3. Third Embodiment Next, the washing device M3 of the third embodiment will be described. In the description of the third embodiment, emphasis will be placed on explaining the differences from the first embodiment, and explanations of matters common to the first embodiment may be omitted.

[0104] Figure 3 is a schematic diagram showing the configuration of the cleaning device M3 of the third embodiment. As shown in this figure, the cleaning device M3 is equipped with an FB generator X3, an FB air line 130, an FB water circulation line 131, an air supply means 132, an air control valve 133, an air check valve 134, an FB supply valve 135, an FB circulation pump 136, and an FB check valve 137, instead of the FB generator X1 and the related elements 110 to 113 (see Figure 1) of the first embodiment.

[0105] The FB water circulation line 131 has its upstream and downstream ends connected to the liquid storage section 5. The FB water circulation line 131 is equipped with, in order from upstream, an FB supply valve 135, an FB circulation pump 136, an FB generator X3, and an FB check valve 137. The FB water circulation line 131 is a line that allows the liquid L in the liquid storage section 5 to circulate through the FB generator X3. The FB supply valve 135 can switch the FB water circulation line 131 open or closed (conductive / non-conductive). The FB circulation pump 136 circulates the liquid L in the FB water circulation line 131. The FB check valve 137 prevents backflow of the liquid L in the FB water circulation line 131.

[0106] The FB airline 130 has its upstream end connected to an air supply means 132 and its downstream end connected to an FB generator X3. The air supply means 132 supplies clean air to the FB airline 130 for generating fine bubbles in the FB generator X3. In this embodiment, the air supply means 132 is, for example, an air filter. The FB airline 130 is provided with an air control valve 133 and an air check valve 134, in that order from the air supply means 132 side. The air control valve 133 allows adjustment of the flow rate or pressure of the air passing through the FB airline 130. The air check valve 134 prevents backflow of air passing through the FB airline 130.

[0107] The FB generator X3 generates fine bubbles using atmospheric pressure air supplied from the FB airline 130. In this embodiment, the FB generator X3 has an ejector, and by flowing a high-pressure working fluid (liquid L) through the nozzle of the ejector, a negative pressure is generated inside, causing the air to be drawn in. This intake air is pulverized inside the FB generator X3 (for example, in the internal mechanism of the diffuser section) and ejected as fine bubbles. The fine bubbles generated by the FB generator X3 are mixed with the liquid L passing through the FB water circulation line 131.

[0108] When shower cleaning or immersion cleaning is performed in the cleaning device M3, the air supply means 132 and the FB circulation pump 136 operate instead of the air supply means 111 in the first embodiment. Also, instead of the air control valve 112 in the first embodiment, the air control valve 133 is appropriately controlled and the FB supply valve 135 is made conductive.

[0109] As a result, the fine bubbles generated by the FB generator X3 mix with the liquid L that flows from the liquid storage unit 5 into the FB water circulation line 131, and this mixed liquid L is returned to the liquid storage unit 5. In this way, as in the first embodiment, cleaning liquid Z is generated as liquid L, and furthermore, fine bubbles are mixed into the liquid L that flows again through the FB water circulation line 131. Therefore, as the circulation of liquid L is repeated, the number of fine bubbles mixed increases, and the cleaning performance of cleaning liquid Z is enhanced.

[0110] Furthermore, when rinsing is performed in the cleaning device M3, the air supply means 132 and the FB circulation pump 136 operate instead of the air supply means 111 in the first embodiment, the FB supply valve 135 is opened, and fine bubbles are generated by the FB generator X3. As a result, it is possible to effectively remove the cleaning solution Z adhering to the object to be cleaned using water (rinsing water) mixed with fine bubbles as liquid L.

[0111] 2-4. Fourth Embodiment Next, the washing device M4 of the fourth embodiment will be described. In the description of the fourth embodiment, emphasis will be placed on explaining the differences from the first embodiment, and explanations of matters common to the first embodiment may be omitted.

[0112] Figure 4 is a schematic diagram showing the cleaning device M4 of the fourth embodiment. As shown in this figure, the cleaning device M4 is equipped with an FB generator X4, an FB airline 140, an air supply means 141, an air control valve 142, and an air check valve 143, instead of the FB generator X1 and the related elements 110 to 113 (see Figure 1) of the first embodiment.

[0113] The FB generator X4 is located within the liquid storage section 5. The FB airline 140 has its upstream end connected to the air supply means 141 and its downstream end connected to the FB generator X4. The air supply means 141 supplies air to the FB airline 140 for generating fine bubbles in the FB generator X4. In this embodiment, the air supply means 141 is a relatively high-pressure pressurized air supply device such as an air compressor or an air cylinder. The FB airline 140 is provided with an air control valve 142 and an air check valve 143, in that order from the air supply means 141 side. The air control valve 142 allows adjustment of the flow rate or pressure of the air passing through the FB airline 140. The air check valve 143 prevents backflow of air passing through the FB airline 140.

[0114] The FB generator X4 generates fine bubbles using pressurized air supplied from the FB airline 140. In this embodiment, the FB generator X4 has a porous ceramic tube and generates fine bubbles by blowing out the pressurized air from micro- and nano-sized pores. The fine bubbles generated by the FB generator X4 are mixed with the liquid L in the liquid reservoir 5.

[0115] When a shower cleaning operation or immersion cleaning operation is performed in the cleaning device M4, the air supply means 141 operates instead of the air supply means 111 in the first embodiment. Also, the air control valve 142 is appropriately controlled instead of the air control valve 112 in the first embodiment.

[0116] As a result, the fine bubbles generated by the FB generator X4 are mixed with the liquid L in the liquid reservoir 5. In this way, the cleaning solution Z is generated as liquid L in the liquid reservoir 5, and furthermore, as the FB generator X4 continues to generate fine bubbles, more fine bubbles are mixed into the liquid L. Therefore, as the FB generator X4 continues to generate fine bubbles, the number of fine bubbles mixed into the liquid L increases, and the cleaning performance of the cleaning solution Z is enhanced.

[0117] Furthermore, when a rinsing operation is performed in the cleaning device M4, the air supply means 141 operates instead of the air supply means 111 in the first embodiment, and fine bubbles are generated by the FB generator X4. As a result, it is possible to effectively remove the cleaning solution Z adhering to the object to be cleaned using water (rinsing water) mixed with fine bubbles as liquid L.

[0118] 2-5. Fifth Embodiment Next, the washing device M5 of the fifth embodiment will be described. In the description of the fifth embodiment, emphasis will be placed on explaining the differences from the first embodiment, and explanations of matters common to the first embodiment may be omitted.

[0119] Figure 5 is a schematic diagram showing the cleaning device M5 of the fifth embodiment. As shown in this figure, the cleaning device M5 is equipped with an FB generator X5, an FB airline 150, an air supply means 151, an air control valve 152, and an air check valve 153, instead of the FB generator X1 and the related elements 110 to 113 (see Figure 1) of the first embodiment.

[0120] The FB generator X5 is located downstream of the water supply valve 18 in the water supply channel 17. The FB airline 140 has its upstream end connected to the air supply means 151 and its downstream end connected to the FB generator X5. The air supply means 151 supplies clean air to the FB airline 150 for generating fine bubbles in the FB generator X5. In this embodiment, the air supply means 151 is, for example, an air filter. The FB airline 150 is provided with an air control valve 152 and an air check valve 153, in order from the air supply means 151 side. The air control valve 152 allows adjustment of the flow rate or pressure of the air passing through the FB airline 150. The air check valve 153 prevents backflow of air passing through the FB airline 150.

[0121] The FB generator X5 generates fine bubbles using atmospheric pressure air supplied from the FB airline 150. In this embodiment, the FB generator X5 has an ejector, and by flowing a high-pressure working fluid (liquid L) through the nozzle of the ejector, a negative pressure is generated inside, causing the air to be drawn in. This intake air is pulverized inside the FB generator X5 (for example, in the internal mechanism of the diffuser section) and ejected as fine bubbles. The fine bubbles generated by the FB generator X5 are mixed with water passing through the water supply channel 17.

[0122] When a shower cleaning operation or immersion cleaning operation is performed in the cleaning device M5, the air supply means 151 operates instead of the air supply means 111 in the first embodiment. Also, the air control valve 152 is appropriately controlled instead of the air control valve 112 in the first embodiment.

[0123] As a result, the fine bubbles generated by the FB generator X5 mix with the water passing through the water supply channel 17, and this mixed water is stored in the liquid storage section 5. Furthermore, when the chemical solution is introduced into the liquid storage section 5 by the chemical solution supply means 9, the chemical solution mixes with the mixed water to generate the cleaning solution Z. In this way, the cleaning solution Z is generated as a liquid L within the liquid storage section 5.

[0124] Furthermore, when a rinsing operation is performed in the cleaning device M5, the air supply means 151 operates instead of the air supply means 111 in the first embodiment, and fine bubbles are generated by the FB generator X5. This makes it possible to effectively remove the cleaning solution Z adhering to the object to be cleaned using water (rinsing water) mixed with fine bubbles as liquid L.

[0125] 3. Summary As described above, each of the washing devices M1 to M5 in the embodiment comprises a washing tank 4 in which the object to be washed is placed, and an FB generator that generates fine bubbles. The washing devices M1 to M5 then generate a washing solution Z using the generated fine bubbles and wash the object to be washed by bringing the washing solution M1 to M5 into contact with the object. Therefore, the washing devices M1 to M5 can generate the washing solution Z and effectively wash the object to be washed by taking advantage of the excellent characteristics of the washing solution Z. As a result of obtaining such a high washing effect, in addition to shortening the washing time, there are also advantages in terms of water saving and energy saving during washing.

[0126] Furthermore, the cleaning units M1 to M5 are equipped with heaters 25 for heating the cleaning solution Z. Therefore, the temperature of the cleaning solution Z can be adjusted to maximize cleaning power, thereby enhancing the cleaning performance of the cleaning solution Z.

[0127] Furthermore, the cleaning devices M1 to M5 are equipped with cleaning nozzles 6 that spray cleaning liquid Z inside the cleaning tank 4, so that when the shower cleaning operation is performed the sprayed cleaning liquid Z hits the object to be cleaned, the object is cleaned. Also, when the immersion cleaning operation is performed the cleaning devices M1 to M5 store cleaning liquid Z inside the cleaning tank 4, so that when the object to be cleaned is immersed in this stored cleaning liquid Z, the object is cleaned.

[0128] The cleaning devices M1 to M4 of the first to fourth embodiments are configured such that a cleaning agent Q (or a cleaning solution Z in which fine bubbles are mixed with the cleaning agent Q) circulates in a circulation path that passes through the inside of the cleaning tank 4, and the fine bubbles generated by the FB generator are mixed with the circulating cleaning agent Q. Therefore, by repeating this circulation, it is possible to increase the number of fine bubbles mixed into the cleaning solution Z and enhance the cleaning performance of the cleaning solution Z.

[0129] Furthermore, since the fine bubble generation mechanism, generation efficiency, and pressure loss characteristics differ depending on the type and specifications of the FB generator, it is preferable to take this into consideration and install an appropriate FB generator in an appropriate location in the cleaning device. In the cleaning devices M1 to M5 of the first to fifth embodiments, FB generators are installed with this point in mind.

[0130] Furthermore, although the FB generators X1 to X5 have different fine bubble generation mechanisms, they are interchangeable. For example, the ejector-type FB generators X4 and X5 do not require an air blower or air compressor, so they are considered suitable for relatively small-capacity cleaning machines where a small amount of fine bubbles are needed. On the other hand, the cavitation-type FB generator X1 and the porous-type FB generators X2 and X3 require an air blower or air compressor, but are considered suitable for relatively large-capacity cleaning machines where a large amount of fine bubbles are needed.

[0131] The cleaning device according to the present invention is not limited to a configuration in which the FB generator is installed in only one location, but may be installed in multiple locations. For example, depending on the specifications of the cleaning device, it is possible to install all or some of the FB generators of the first to fifth embodiments in a single cleaning device. For example, in a single cleaning device, an FB generator may be installed in the circulation piping 27 as in the first embodiment, and an FB generator may also be installed in the water supply channel 17 as in the fifth embodiment.

[0132] It should be noted that the above embodiments are illustrative in all respects and not restrictive. The technical scope of the present invention is indicated by the claims rather than by the above descriptions of embodiments, and should be understood to include all modifications that fall within the meaning and scope equivalent to the claims.

[0133] <Contribution to the United Nations-led Sustainable Development Goals (SDGs)> The cleaning solution disclosed herein improves cleaning power, enabling both shorter cleaning times and lower cleaning temperatures. This allows for significantly reduced energy consumption during cleaning operations. This can contribute to achieving SDG Goal 7, "Affordable and Clean Energy." Furthermore, shorter cleaning times and fewer rinses lead to water conservation, helping to alleviate water shortages. This can contribute to achieving SDG Goal 6, "Clean Water and Sanitation for All."

[0134] This invention can be used in cleaning solutions and the like used in automatic washing machines.

[0135] 1. Washer (M1-M5) 2. FB Generator (X1-X5) 3. Washing Rack 4. Shelf 5. Washing Tank 6. Liquid Storage Unit 7. Washing Nozzle 8. Water Supply Means 9. Drainage Means 10. Chemical Supply Means 11. Heating Means 12. Circulation Means 13. Inclined Surface 14. Water Distribution Member 14. Washing Arm 15. Water Duct 16. Nozzle Hole 17. Water Supply Channel 18. Water Supply Valve 19. Liquid Level Detector 20. Drainage Channel 21. Drainage Valve 22. Chemical Tank 23. Liquid Supply Channel 24. Chemical Pump 25. Heater 26. Temperature Sensor 27. Circulation Piping 28. Circulation Pump 29. Check Valve 81. Shower Valve 82. Shower Washing Float Sensor 83. Immersion Washing Float Sensor 84. Temperature Sensor 85. Immersion Washing Line 86. Immersion Washing Valve 87. Flow sensors 110, 120, 130, 140, 150 FB Airline 111, 122, 132, 141, 151 Air supply means 112, 123, 133, 142, 152 Air control valve 113, 124, 134, 143, 153 Air check valve 121 FB bypass line 125 FB control valve 131 FB water circulation line 135 FB supply valve 136 FB circulation pump 137 FB check valve

Claims

1. A cleaning solution comprising a solution containing a polyoxyalkylene-based nonionic surfactant with a cloud point of 30 to 50°C and an HLB of 10 to 16, and a polycarboxylic acid and / or a salt thereof, wherein fine bubbles are also present.

2. The cleaning solution according to claim 1, wherein the solution further comprises at least one of a chelating agent, an alkaline agent, and an antifoaming agent.

3. A cleaning device comprising a cleaning tank in which an object to be cleaned is contained, and an FB generator for generating the fine bubbles, wherein the cleaning device generates the cleaning solution described in claim 1 or claim 2 using the generated fine bubbles, and cleans the object to be cleaned by bringing the cleaning solution into contact with the object to be cleaned.

4. The cleaning device according to claim 3, wherein the solution is circulated in a circulation path that passes through the inside of the cleaning tank, and the generated fine bubbles are mixed into the circulating solution.

5. The cleaning device according to claim 3, further comprising a heater for heating the cleaning solution.

6. The cleaning device according to claim 3, comprising a cleaning nozzle for spraying the cleaning liquid inside the cleaning tank, wherein the sprayed cleaning liquid comes into contact with the object to be cleaned, thereby cleaning the object to be cleaned.

7. The cleaning device according to claim 3, wherein the cleaning liquid is stored inside the cleaning tank, and the object to be cleaned is cleaned by immersing the object to be cleaned in the stored cleaning liquid.

8. A method for generating the cleaning solution according to claim 1 or claim 2, comprising: a first step of generating the fine bubbles; and a second step of mixing the fine bubbles into the solution.

9. A cleaning method for cleaning an object to be cleaned by bringing the cleaning solution described in claim 1 or claim 2 into contact with the object to be cleaned.

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