JP2019155332A - Washing device and washing method - Google Patents

Abstract

To provide a washing device and a washing method capable of reducing a used amount of water, in washing of a washing object such as an instrument or a tableware.SOLUTION: There is provided a washing device for washing a washing object by using liquid. In the washing device 1, at least one combination selected from the following combinations is used as the liquid: (1) a combination of (c) alkali water and (b) pure water, (2) a combination of (c) alkali water, (a) hardness component-containing water and (b) pure water, (3) a combination of (c) alkali water, (d) surfactant-containing water, (a) hardness component-containing water and (b) pure water.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cleaning apparatus and a cleaning method for cleaning an object to be cleaned such as an instrument and tableware.

  In an automatic washing apparatus for automatically washing instruments such as laboratory instruments and tableware, a detergent such as a neutral detergent containing a surfactant is usually used. In particular, the use of a surfactant is indispensable for cleaning instruments or tableware to which oil or the like is attached.

  When a surfactant is used for cleaning, it is necessary to rinse with rinse water to wash away the surfactant. Rinsing depends on the hardness and temperature of the rinsing water, but requires several times the amount of water used when no surfactant is used, and the amount of drainage increases accordingly.

Japanese Patent No. 6236342

  The objective of this invention is providing the washing | cleaning apparatus and washing | cleaning method which can reduce the usage-amount of water in washing | cleaning of washing | cleaning target objects, such as an instrument and tableware.

  The present invention is a cleaning apparatus for cleaning an object to be cleaned using a liquid, and as the liquid, at least (1) a combination of alkaline water and pure water, (2) alkaline water, hardness component-containing water, and pure water (3) A cleaning device using at least one combination of alkaline water, surfactant-containing water, hardness component-containing water, and pure water.

  In the cleaning apparatus, it is preferable that oil is attached to the object to be cleaned, and the combination of liquids to be used is selected and the cleaning order in the combination is switched according to the degree of oil content of the object to be cleaned. .

  The cleaning apparatus preferably includes a conductivity measuring unit that measures the conductivity after UV oxidation of the cleaning waste liquid for measuring the degree of oil adhesion of the cleaning target.

  In the said washing | cleaning apparatus, when using the combination of said (2) or (3) as said liquid, it is preferable to use the water containing the concentrated water of a reverse osmosis membrane apparatus as said hardness component containing water.

  The present invention is also a cleaning method for cleaning an object to be cleaned using a liquid, wherein the liquid includes at least (1) a combination of alkaline water and pure water, and (2) alkaline water, hardness component-containing water, and pure water. A cleaning method using at least one combination of a combination of water and (3) a combination of alkaline water, surfactant-containing water, hardness component-containing water, and pure water.

  In the cleaning method, it is preferable that oil is attached to the object to be cleaned, and the combination of liquids to be used is selected and the cleaning order in the combination is switched according to the degree of oil content of the object to be cleaned. .

  In the cleaning method, it is preferable to measure the conductivity of the cleaning waste liquid after UV oxidation in order to measure the degree of oil adhesion of the cleaning object.

  In the cleaning method, when the combination (2) or (3) is used as the liquid, it is preferable to use water containing concentrated water from a reverse osmosis membrane device as the hardness component-containing water.

  In the present invention, the amount of water used can be reduced in the cleaning of objects to be cleaned such as instruments and tableware.

It is a schematic block diagram which shows an example of the washing | cleaning apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the other example of the washing | cleaning apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the conventional washing | cleaning apparatus used by the comparative example.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

  A cleaning apparatus according to an embodiment of the present invention is a cleaning apparatus that cleans an object to be cleaned using a liquid. As the liquid, at least (1) a combination of alkaline water and pure water, and (2) alkaline water and hardness components A combination of containing water and pure water, (3) at least one combination of alkaline water, surfactant-containing water, hardness component-containing water, and pure water is used.

  An outline of an example of the cleaning apparatus according to the present embodiment is shown in FIG. 1 and the configuration thereof will be described.

  The cleaning apparatus 1 of FIG. 1 includes a sealable cleaning tank 10 that houses at least one cleaning object 68. The cleaning tank 10 includes at least one cleaning nozzle that ejects a cleaning liquid. For example, the cleaning tank 10 includes at least one cleaning nozzle 58 provided in the lower part of the cleaning tank 10 and an upper part of the cleaning tank 10. At least one washing nozzle 60 provided.

  A liquid supply pipe 46 is connected to the lower liquid inlet of the cleaning tank 10 via a pump 16 and a valve 28. The liquid supply pipe 46 communicates with the pipe 62, and at least one cleaning nozzle 58 is connected to the pipe 62. A liquid supply pipe 50 branched from between the pump 16 and the valve 28 in the liquid supply pipe 46 is connected to the liquid upper inlet of the cleaning tank 10 via the valve 32. The liquid supply pipe 50 communicates with the pipe 64, and at least one cleaning nozzle 60 is connected to the pipe 64.

  The liquid supply pipe 46 is connected to (a) a pipe 36 for supplying hardness component-containing water via the valve 18, and (b) a pipe 38 for supplying pure water is connected via the valve 20. (C) A pipe 40 for supplying alkaline water is connected via the valve 22, and (d) a pipe 42 for supplying surfactant-containing water is connected via the valve 24. A pipe 44 for supplying (e) acid water may be connected to the liquid supply pipe 46 via the valve 26.

  The circulation liquid outlet of the cleaning tank 10, the connection point of the pipe 44 in the liquid supply pipe 46, and the pump 16 are connected by a circulation pipe 48 via the valve 30. A cleaning drain pipe 52 is connected to the cleaning drain outlet of the cleaning tank 10 via a valve 34. An oil adhesion degree measuring device 12 is installed on the upstream side of the valve 34 in the cleaning drainage pipe 52 as an oil adhesion degree measuring means for measuring the degree of oil adhesion of the object to be cleaned.

  A gas supply pipe 54 is connected to the gas inlet of the cleaning tank 10 through the filter 14. An exhaust pipe 56 is connected to the gas outlet of the cleaning tank 10.

  The oil adhesion degree measuring device 12 and the valves 18, 20, 22, 24, 26 are connected to the control unit 70 by electrical connection or the like.

  The operation of the cleaning method and the cleaning apparatus 1 according to this embodiment will be described.

  At least one cleaning object 68 is accommodated in the cleaning tank 10 of the cleaning apparatus 1. The object 68 to be cleaned is accommodated on a gantry 66 installed in the cleaning tank 10, for example. The gantry 66 is, for example, a net-like one made of resin or metal that can pass liquid or gas.

  One of the valves 18, 20, 22, 24, 26 is opened, the valves 28, 32 are opened, the valves 30, 34 are closed, the pump 16 is activated, and the liquid is used for cleaning. Any one of (a) hardness component-containing water, (b) pure water, (c) alkaline water, (d) surfactant-containing water, and (e) acidic water passes through the liquid supply pipe 46 and the pipe 62. A target to be cleaned is sprayed from the cleaning nozzle 58 and from the cleaning nozzle 60 through the liquid supply pipe 46, the liquid supply pipe 50, and the pipe 64 so as to hit the cleaning target 68 accommodated in the cleaning tank 10 for a predetermined time. The object 68 is cleaned (cleaning process).

  Here, in the cleaning step, at least (1) (c) a combination of alkaline water and (b) pure water, (2) (c) alkaline water and (a) hardness component-containing water ( b) a combination with pure water, (3) at least one combination of (c) alkaline water, (d) surfactant-containing water, (a) hardness component-containing water, and (b) pure water. Used.

  (1) In the case of a combination of (c) alkaline water and (b) pure water, for example, (c) pure water having a high effect of removing deposits, (b) pure water as a rinse after washing with alkaline water Cleaning by is performed.

(2) In the case of a combination of (c) alkaline water, (a) hardness component-containing water, and (b) pure water,
For example, after (c) cleaning with alkaline water having a high effect of removing deposits is performed, (a) cleaning with hardness component-containing water is performed, and finally (b) cleaning with pure water is performed as a rinse. .

  (3) In the case of a combination of (c) alkaline water, (d) surfactant-containing water, (a) hardness component-containing water, and (b) pure water, for example, a high effect of removing deposits (c) After washing with alkaline water, (d) washing with surfactant-containing water is performed, then (a) washing with hardness component-containing water is performed, and finally (b) washing with pure water is performed as a rinse. Is done. (D) After the cleaning with the surfactant-containing water is performed, it is preferable that the cleaning with the hardness component-containing water is performed.

  In the cleaning method and the cleaning apparatus according to the present embodiment, since at least one combination of the above (1), (2), and (3) is used as the liquid, the cleaning effect with alkaline water is particularly high. It is possible to reduce the amount of water used in the cleaning of objects to be cleaned such as instruments and tableware. Moreover, the usage-amount of surfactant can be reduced and the amount of washing | cleaning waste_water | drain can be reduced.

  In the cleaning process, after cleaning with a predetermined amount of liquid, the valves 18, 20, 22, 24, and 26 are closed, the valve 30 is opened, and the cleaning liquid is supplied to the circulation pipe 48, The cleaning may be performed by circulating through the liquid supply pipe 46 and through the circulation pipe 48, the liquid supply pipe 46, and the liquid supply pipe 50. In particular, when circulating cleaning is performed in (b) rinsing with pure water or the like, the amount of water used can be further reduced.

  After completion of the cleaning process, the pump 16 is stopped, the valves 18, 20, 22, 24, and 26 are closed, the valves 28, 30, and 32 are closed, the valve 34 is opened, and the cleaning waste liquid is discharged. Is discharged through the cleaning drainage pipe 52 (cleaning drainage discharging step).

  After completion of the cleaning drainage process, the valves 18, 20, 22, 24, 26, 28, 30, 32, 34 are closed, and a drying gas passes through the gas supply pipe 54 and enters the cleaning tank 10. Then, the object to be cleaned 68 is dried by being exhausted through the exhaust pipe 56 (drying process). The drying gas is preferably supplied after dust, dust, and the like in the gas are removed through the filter 14 in order to suppress contamination of the object to be cleaned after cleaning.

  The cleaning target 68 is not particularly limited as long as it can be cleaned with water. Examples of the cleaning object 68 include instruments such as laboratory instruments, tableware, valves, pipe joints, and the like made of glass, ceramics, resin, metal, and enamel.

  In the cleaning method and the cleaning apparatus according to the present embodiment, the cleaning target 68 is preferably applied when an oil component is attached. In particular, by using alcal water as a cleaning liquid, it is possible to remove oil adhering with a small amount of water used.

  When oil is attached to the object to be cleaned, select at least one of the combinations (1), (2) and (3) of the liquid to be used according to the degree of oil attached to the object to be cleaned However, it is preferable to switch the cleaning order within the combination of (1), (2) and (3).

  When oil is adhered to the object to be cleaned, for example, a small amount of (a) hardness component-containing water, (b) pure water, (c) alkaline water, (d) surfactant-containing water, (e) acidic water At least one of these, preferably a small amount of (c) washing with alkaline water, and with respect to the washing drainage, the oil content of the washing drainage is measured by the oil adhesion degree measuring device 12 installed in the washing drainage pipe 52. The oil content measured and adhered to the object to be cleaned is measured (oil content measurement step). According to the degree of oil adhesion of the cleaning object measured by the oil adhesion degree measuring device 12, select at least one combination of the above-mentioned (1), (2), (3) of the liquid to be used, What is necessary is just to switch the washing | cleaning order in the combination of said (1), (2), (3). For example, the controller 70 controls the opening / closing, opening degree, and the like of the valves 18, 20, 22, 24, and 26 according to the oil adhesion degree of the object to be cleaned measured by the oil adhesion degree measuring device 12. A combination of the above (1), (2), and (3) of the liquid is selected, and the cleaning order within the combination of (1), (2), and (3) may be switched.

  As an oil adhesion degree measuring means for measuring the degree of oil adhesion on the object to be cleaned, a conductivity measuring device, a pH measuring device, an emulsified turbidity measuring device, etc. for measuring the conductivity after UV oxidation of the cleaning effluent Is mentioned. Of these, a conductivity measuring device that measures the conductivity after UV oxidation is preferable from the viewpoint of resolution, economy, and the like. This conductivity measuring device is a device that measures conductivity after photo-oxidation of an organic substance such as oil by UV irradiation including, for example, 185 nm ultraviolet rays in the cleaning waste liquid. Although there is an emulsion turbidity measurement method as a method for measuring oil content, it may not be suitable for measuring low-concentration oil content because of its high detection limit.

  For example, when the adhesion amount of oil is relatively large (for example, when the conductivity of the washing drainage is 10 μS / cm or more), (3) (c) alkaline water and (d) surfactant-containing water ( (a) After a combination of hardness component-containing water and (b) pure water is selected and highly effective to remove deposits (c) After washing with alkaline water, (d) Washing with surfactant-containing water Next, (a) cleaning with hardness component-containing water is performed, and finally (b) cleaning with pure water is performed as a rinse.

  For example, when the amount of attached oil is relatively small (for example, when the conductivity of the cleaning waste liquid is less than 10 μS / cm), a combination of (1) (c) alkaline water and (b) pure water is selected. (C) After cleaning with alkaline water, (b) cleaning with pure water is performed as a rinse. Or (2) (c) Alkaline water, (a) Hardness component-containing water, and (b) Pure water combination is selected, and (c) After washing with alkaline water, (a) Hardness component-containing Cleaning with water is performed, and finally (b) cleaning with pure water is performed as a rinse.

  After completion of the cleaning step, for example, at least one of a small amount of (a) hardness component-containing water, (b) pure water, (c) alkaline water, (d) surfactant-containing water, (e) acidic water Preferably, the washing waste liquid is washed with a small amount of (c) alkaline water, and the oil content of the washing waste liquid is measured by the oil adhesion degree measuring device 12 installed in the washing drain pipe 52, and the object to be washed The oil attached to the surface may be checked (oil check process). The cleaning process may be performed again according to the degree of oil adhesion of the checked cleaning target. For example, when the adhesion amount of oil is relatively large (for example, when the conductivity of the cleaning drainage is 10 μS / cm or more), the cleaning process may be performed again. When the adhesion amount of oil is relatively small (for example, when the conductivity of the cleaning waste liquid is less than 10 μS / cm), the drying process may be performed.

  (A) Hardness component containing water is water whose content of calcium salt and magnesium salt is 10-300 mg / L, for example, tap water. Moreover, you may use the hardness adjustment water which mixed the concentrated water obtained by a reverse osmosis membrane process with tap water as hardness component containing water.

  (B) Pure water is water having a conductivity of 2 μS / cm or less. As pure water, permeated water obtained by treatment with a reverse osmosis membrane may be used.

(C) Alkaline water is water of pH 8.0 or more, preferably pH 10.0 to 12.5. Examples of the alkaline water include an aqueous sodium hydroxide solution and an aqueous potassium hydroxide solution, and an aqueous sodium hydroxide solution is preferred from the viewpoint of economy. Alkaline water may be alkaline electrolyzed water such as a sodium hydroxide aqueous solution obtained by electrolyzing a sodium hydrogen carbonate (NaHCO ₃ ) solution, and has a high cleaning effect, particularly from the viewpoint of a high oil cleaning effect. Alkaline electrolyzed water is preferred. Examples of the alkaline water include 0.2% by weight sodium hydroxide aqueous solution, sodium hydroxide aqueous solution having a concentration higher than 0.2% by weight diluted with pure water to 0.2% by weight, A 0.2 wt% sodium hydroxide aqueous solution, which is alkaline electrolyzed water obtained by electrolyzing a 0.42 wt% sodium bicarbonate (NaHCO ₃ ) aqueous solution, can be used. The alkaline water preferably does not contain a surfactant.

  (D) Surfactant-containing water is water containing a surfactant, for example, water containing 1000 to 50000 mg / L of a surfactant. Surfactants include, for example, anionic compounds such as sulfonates or sulfates, cationic salts of amine salts or quaternary ammonium salts, and amino acids and betaines of carboxylates. Examples include amphoteric ones, ester type or ether type nonionic ones, and anionic and nonionic ones are preferred from the standpoint of a cleaning effect on oil.

  (E) Acidic water is water having a pH of 5.0 or less, preferably pH 2.0 to 4.0. Examples of acidic water include aqueous hydrochloric acid and aqueous sulfuric acid, and an aqueous hydrochloric acid is preferred from the viewpoint of economy. As acidic water, for example, a 0.1 wt% aqueous hydrochloric acid solution can be used. Acidic water can be used in the cleaning process when the object to be cleaned has adhesion of metals such as heavy metals such as iron (Fe) and manganese (Mn). It is preferable that acidic water does not contain surfactant.

  The temperature of (a) hardness component-containing water, (b) pure water, (c) alkaline water, (d) surfactant-containing water, and (e) acidic water is usually 15 to 30 ° C., and has a cleaning effect. You may use the warmed water heated to 40-90 degreeC from points, such as raising.

  The flow rate of the liquid in the cleaning process is not particularly limited. For example, the liquid flow rate may be 0.05 to 0.5 L / min per liter of the cleaning device. 25 L / min. For example, the oil content in the cleaning effluent is measured by the oil adhesion degree measuring means, and the opening / closing, opening degree, etc. of the valves 18, 20, 22, 24, 26 are controlled by the control unit 70 based on the measured value. In addition, the flow rate of the liquid in the cleaning process may be adjusted.

  The cleaning time in the cleaning step is not particularly limited, but may be, for example, 5 to 20 minutes. For example, the oil content in the cleaning effluent is measured by the oil adhesion degree measuring means, and the opening / closing time of the valves 18, 20, 22, 24, and 26 is controlled by the control unit 70 based on the measured value. Also good.

  Oils are liquids or solids that are insoluble or poorly soluble in water and are generally compounds of fatty acids and glycerin, for example, vegetable oils and aromatic hydrocarbons mainly composed of oleic acid and linoleic acid. Examples include mineral oil as a component.

  It is sufficient that at least one cleaning nozzle is provided inside the cleaning tank 10, and a plurality of cleaning nozzles are preferably provided. The cleaning nozzle 58 is provided at the lower part of the cleaning tank 10 and is a nozzle for spraying a cleaning liquid on the cleaning target 68 from the lateral direction, for example, and there is no particular limitation on the form and number thereof. In the case where the cleaning nozzle 58 is provided, at least one cleaning nozzle may be provided, and the form and number of the cleaning nozzles 58 may be appropriately determined according to the purpose of cleaning and the like.

  The cleaning nozzle 60 is provided in the upper part of the cleaning tank 10 and is a nozzle for spraying a cleaning liquid onto the cleaning object 68 from the upper part of the cleaning tank 10 downward. There is no limit. In the case where the cleaning nozzle 60 is provided, at least one cleaning nozzle may be provided, and the form and number of the cleaning nozzles 60 may be appropriately determined according to the purpose of cleaning and the like.

  As a cleaning method, in addition to a method using a cleaning nozzle, ultrasonic cleaning in a state where an object to be cleaned is immersed in a cleaning liquid may be used.

  The gas for drying is, for example, a dry gas such as dry air, and can be obtained by, for example, heating or dehumidifying the air. The dry gas preferably has a relative humidity of 20% or less. The temperature of the gas for drying is usually 40 to 90 ° C., but 60 to 80 ° C. is preferable in consideration of the sterilization effect and damage to the drying object having low heat resistance. Moreover, when using what heated air as gas for drying, energy, such as electricity required for heating, can be reduced by carrying out internal circulation of some air in a washing | cleaning apparatus.

  The filter 14 is not particularly limited as long as it can remove dust, dust and the like in the gas, and examples thereof include a HEPA filter having a 99.99% removal performance of 0.3 μm fine particles.

  FIG. 2 shows a cleaning apparatus including a reverse osmosis membrane apparatus for producing pure water as another example of the cleaning apparatus. The cleaning device 3 in FIG. 2 includes a reverse osmosis membrane device 72 as a reverse osmosis membrane treatment means for producing pure water.

  In the cleaning device 3 of FIG. 2, a feed water pipe 74 for supplying feed water is connected to the inlet of the reverse osmosis membrane device 72, and a permeate pipe 76 is connected to the permeate outlet of the reverse osmosis membrane device 72. A concentrated water pipe 78 is connected to the concentrated water outlet. The permeated water pipe 76 is connected to a pipe 38 for supplying (b) pure water. Moreover, the concentrated water piping 78 may be connected in the middle of the piping 36 for supplying (a) hardness component containing water.

  In the cleaning device 3 of FIG. 2, the supply water is supplied to the reverse osmosis membrane device 72 through the supply water pipe 74, and reverse osmosis membrane treatment is performed in the reverse osmosis membrane device 72 to obtain permeated water and concentrated water (reverse) Osmosis membrane treatment process). The permeated water is used as a cleaning liquid in the cleaning tank 10 as (b) pure water through the permeated water pipe 76 and the pipe 38. The concentrated water may be mixed with hardness component-containing water such as tap water in the pipe 36 through the concentrated water pipe 78 and used as a cleaning liquid in the cleaning tank 10. That is, when the combination of (2) or (3) is used as the cleaning liquid, it is preferable to use water containing the concentrated water of the reverse osmosis membrane device as the hardness component-containing water. This has the advantage that the rinsing time for washing away the surfactant can be shortened.

  The reverse osmosis membrane device 72 is not particularly limited as long as it can obtain pure water using a reverse osmosis membrane.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

<Examples 1-3 and Comparative Example 1>
Using the cleaning apparatus shown in FIG. 1 or FIG. 2, glass beakers with different oil adhesion amounts were cleaned as cleaning objects. The details of each cleaning liquid used are shown in Table 1. As a means for measuring the degree of oil adhesion, a conductivity measuring device (RG12, manufactured by Organo Corporation) was used to measure the conductivity after photooxidation of the oil by UV irradiation containing 185 nm ultraviolet rays in the cleaning waste liquid. As shown in Table 2, after washing with a small amount of alkaline water (100 mL / min × 1 min), after measuring the conductivity of the washing drainage, the operation process was changed according to the measured value of conductivity. Washing was performed (Examples 1 to 3). In Comparative Example 1, cleaning was performed using a conventional cleaning device 5 that does not use alkaline water as shown in FIG. Table 2 shows the ratio of the amount of water used in Examples 1 to 3 to Comparative Example 1.

  Thus, the amount of water used can be reduced in the cleaning of objects to be cleaned such as utensils and tableware by the cleaning apparatus and the cleaning method of the example.

  1, 3, 5 Cleaning device, 10 Cleaning tank, 12 Oil content adhesion measuring device, 14 Filter, 16 Pump, 18, 20, 22, 24, 26, 28, 30, 32, 34 Valve, 36, 38, 40, 42, 44, 62, 64 Piping, 46, 50 Liquid supply piping, 48 Circulation piping, 52 Cleaning drainage piping, 54 Gas supply piping, 56 Exhaust piping, 58, 60 Cleaning nozzle, 66 Base, 68 Object to be cleaned, 70 Control unit, 72 reverse osmosis membrane device, 74 feed water pipe, 76 permeate pipe, 78 concentrated water pipe.

Claims (8)

A cleaning device for cleaning an object to be cleaned using a liquid,
As the liquid, at least (1) a combination of alkali water and pure water, (2) a combination of alkali water, hardness component-containing water and pure water, (3) alkali water, surfactant-containing water and hardness component-containing water A cleaning apparatus using at least one combination of a combination of pure water and pure water. The cleaning device according to claim 1,
An oil is attached to the object to be cleaned, and the combination of liquids to be used is selected according to the degree of oil adhering to the object to be cleaned, and the cleaning order in the combination is switched. The cleaning apparatus according to claim 2,
A cleaning apparatus comprising a conductivity measuring means for measuring the conductivity after UV oxidation of the cleaning waste liquid for measuring the degree of adhesion of oil on the cleaning object. The cleaning apparatus according to any one of claims 1 to 3,
When using the combination of said (2) or (3) as said liquid, the washing | cleaning apparatus characterized by using the water containing the concentrated water of a reverse osmosis membrane apparatus as said hardness component containing water. A cleaning method for cleaning an object to be cleaned using a liquid,
As the liquid, at least (1) a combination of alkali water and pure water, (2) a combination of alkali water, hardness component-containing water and pure water, (3) alkali water, surfactant-containing water and hardness component-containing water A cleaning method using at least one combination of a combination of pure water and pure water. The cleaning method according to claim 5,
A cleaning method, wherein oil is attached to the object to be cleaned, and the combination of liquids to be used is selected according to the degree of oil content of the object to be cleaned, and the order of cleaning in the combination is switched. The cleaning method according to claim 6,
In order to measure the degree of oil adhesion of the object to be cleaned, a conductivity after UV oxidation of the cleaning waste liquid is measured. A cleaning method according to any one of claims 5 to 7,
When the combination of (2) or (3) is used as the liquid, the cleaning method is characterized by using water containing concentrated water of a reverse osmosis membrane device as the hardness component-containing water.

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