JP2016166416A - Cleaning treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning treatment method of an object to be cleaned, using a water-soluble processing oil, causing no environmental load, suppressing energy consumption and efficiently removing fats and water of an adhering processing oil, so as to treat a processed product processed by using a water-soluble processing oil comprising water, a lubricating-oil and a surface active agent, and its cutting chips in the following step.SOLUTION: A cleaning processing method is a method for cleaning as an object to be cleaned, a processed product cut with a water-soluble processing oil and adhered with a water-soluble processing oil, or cutting chips generated by cutting with a water-soluble processing oil, and adhered with a water-soluble processing oil. The cleaning processing method includes: gasifying and separating moisture of an aqueous processing oil adhering to the object to be cleaned, and simultaneously bringing into contact with a hydrophobic cleaning liquid having an ability of melting and dispersing oils and a surface active agent contained in a processing oil; heating the product under a condition of a temperature and pressure allowing gasifying moisture followed by cleaning; and performing decompression drying by sensible heat of the object to be cleaned.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a workpiece to which a processing oil (that is, cutting oil) cut using a water-soluble processing oil (that is, a water-soluble cutting oil) is attached, a cutting scrap to which a processing oil generated by cutting is attached, Cutting chips, etc. (hereinafter also referred to as cutting swarf including cutting swarf, cutting swarf, cutting swarf, polishing swarf, etc.) (Hereinafter, in the present specification, including these workpieces and swarf, etc., to be cleaned) In the cleaning step when the processed product is shipped as a product, or in the next step. It is necessary for pre-processing of the melting process of cutting waste, because it is reused without discarding it as a useful resource in the cleaning process required for plating and coating treatment In the cleaning process Also in the surface, excellent in terms of economy, cleaning method relating to the object to be cleaned to a water-soluble machining oil is adhered.

  The environment for obtaining products by cutting by machining has changed so that the machine is automated by numerical control from the era when it was manually operated, and processing that increases productivity at high speed is required, and demands for cutting oil The performance has changed. In other words, for the purpose of reducing the friction between the cutting tool and the workpiece to be machined, there are functions such as cooling of the heat generated by high-speed machining and the function of eliminating cutting waste generated during cutting so as not to interfere with machining. It is now required to have both.

  A water-soluble processing oil having a low environmental load has come to be used as a cutting processing oil for such purposes. Water-soluble processing oil is water that is excellent as the main agent of processing oil for the above purposes due to specific heat, thermal conductivity, evaporation heat, non-combustibility, etc., to reduce the friction between the cutting tool and workpiece during cutting In general, it is a type to which a mineral oil or the like and a surfactant for dispersing them are added.

  The processed product cut with water-soluble processing oil has the above-mentioned water-soluble processing oil attached to it, and the attached liquid containing oil and fat, surfactants, etc., which are lubricant components for cutting and cutting, and moisture is accompanied. ing. For this reason, in order to use the machined product for plating or painting, which is the next process, or to use it in the melting process for cutting waste that is reused without being discarded as a useful resource. Furthermore, it is necessary to remove the adhering liquid as a pretreatment.

If the processed oil containing oil and fat or moisture adheres to the machined product, it may hinder processing in the next process or unfavorable combustion in the melting process to reuse cutting waste as a raw material Or smoke, or slag. The generation of smoke is not preferable in the environment, and when slag is generated, the recycling rate of the melted material is reduced, and therefore, the removal of the adhering liquid is further required.
A method for removing the adhering liquid containing oils and fats and moisture from the cutting and cutting lubricant adhering to the aluminum scrap in order to reuse the aluminum scrap generated during the manufacture and processing of aluminum products as a useful aluminum resource. It is disclosed in Document 1. However, no mention is made regarding effective removal of oil and fat and water adhering to the aluminum scrap.

  In addition, in the previous application (Japanese Patent Application No. 2013-186638), the present applicant cuts water with a water-soluble processing oil and attaches the water-soluble processing oil to a workpiece to be cleaned such as a cutting product or cutting waste. We proposed a method of drying and removing moisture in water-soluble processing oil and then washing and removing it with a cleaning solution having a dissolving ability capable of cleaning the remaining components of the water-soluble processing oil attached to the object to be cleaned.

JP 2012-61392 A

Conventionally, the water-soluble processing oil that adheres to the object to be cleaned is not compatible with the cleaning liquid because the water-soluble processing oil that adheres to the object to be cleaned is not compatible unless the water-soluble processing oil is washed with a hydrophilic cleaning liquid. Since it is repelled by water, which is the main component of oil, cleaning liquids that can be used are limited to hydrophilic glycols, N-methylpyrrolidone, water, and the like.
When these hydrophilic cleaning liquids are used as cleaning liquids, this is a method of reducing the amount of processing oil adhering to the object to be cleaned by dispersing and diluting with the cleaning liquid adhering to the object to be cleaned, and has the following problems.
・ A large amount of separation equipment, floor space, and chemicals are required for the treatment of oil in the cleaning waste liquid generated by separating the oil transferred to the cleaning liquid, and a large amount of energy is required when incineration is required. As a result, the amount of CO ₂ generated also increases.

-Since the water adhering to the object to be cleaned elutes into the cleaning solution, the concentration of the cleaning solution is reduced and the cleaning effect of the cleaning solution is reduced. Therefore, the water dissolved in the cleaning solution is separated from the cleaning solvent and only the water is removed from the system. However, special equipment and operation are required.
-When water is dissolved in a water-soluble solvent, the boiling point is about 100 ° C, and the temperature of the object to be cleaned should be raised to 100 ° C or higher at the liquid temperature of the cleaning liquid to increase the temperature before drying of the object to be cleaned. In this case, the cleaning solution temperature is limited, which is not preferable in the drying process.
When water is dissolved in the cleaning solvent, the latent heat of vaporization of the liquid increases, so that the amount of heat necessary for drying the cleaning liquid adhering to the object to be cleaned increases, which hinders the drying process.
・ If the water in the adhering liquid evaporates before the cleaning operation of the adhering liquid on the object to be cleaned, and hydrophobic oil is formed on the surface of the object to be cleaned, water-soluble cutting oil Other objects to be cleaned cannot be cleaned.

-When a product to be machined uses a water-soluble processing oil and an object to be cleaned using a hydrophobic processing oil, an object to be cleaned that cannot be cleaned with a hydrophilic cleaning liquid is generated.
In addition, in the cleaning method proposed by the present applicant in the previous application (Japanese Patent Application No. 2013-186638), water-soluble processing oil is used as a method for drying and removing water in the water-soluble processing oil adhering to the object to be cleaned. Water-soluble processing oil in the gas phase, such as a method of heating an object to be cleaned, a method of reducing pressure without heating, a method of heating and decompressing, or a method of passing dry air or a dry gas of nitrogen gas When water is gasified and dried under conditions where the water content is gasified, the remaining components of the water-soluble processing oil adhering to the object from which the water has been removed are the van der Waals forces. It has been found that there is a case where a strong film is formed with such a force and may be formed as a composition that is difficult to dissolve with a normal solvent.
Various problems such as those mentioned above are solved, and processed products processed with water-soluble processing oil composed of water, lubricating oil, surfactants, etc., and their cutting waste are processed in the next step Therefore, there is a cleaning method for the object to be cleaned with water-soluble processing oil that efficiently removes the oil and fat content and water content of the water-soluble processing oil that adheres to the environment without reducing the energy consumption. It was requested.
The present invention aims to solve such a demand.

As a result of earnest research to solve the various problems and difficulties described above, the present inventors have found that the above problems and difficulties can be solved by adopting the following method. The present invention has been proposed.
That is, the cleaning method of the present invention provides a cleaning method having the following configurations (1) to (9).

(1) Washing a processed product that is cut with water-soluble processing oil and to which water-soluble processing oil is attached, or cutting waste that is generated by cutting with water-soluble processing oil and to which water-soluble processing oil is attached, as an object to be cleaned In this method, the object to be cleaned is brought into contact with the hydrophobic cleaning liquid, and at the same time, the object to be cleaned is cleaned by heating under conditions of temperature and pressure at which water in the water-soluble processing oil is gasified. A cleaning method.
(2) Washing processing using water-soluble processing oil as a workpiece to be processed, processed products to which water-soluble processing oil adheres, or cutting waste generated by cutting with water-soluble processing oil and to which water-soluble processing oil adheres A water-soluble processing oil adhering to the object to be cleaned, at a temperature at which the water content is gasified, and having the ability to dissolve or disperse at least the oil and / or surfactant contained in the water-soluble processing oil. Yes, heated in contact with a hydrophobic cleaning liquid having a partial pressure lower than the partial pressure of water at that temperature, and gasifies the water of the water-soluble processing oil adhering to the object to be cleaned and at the same time adheres to the object to be cleaned A cleaning treatment method, wherein at least an oil component and / or a surfactant of a water-soluble processing oil is dissolved or dispersed in a hydrophobic cleaning solution, removed, and washed.

(3) Washing processed products that are cut with water-soluble processing oil and to which water-soluble processing oil adheres, or cutting waste that is generated by cutting with water-soluble processing oil and to which water-soluble processing oil adheres, as an object to be cleaned A treatment method in which an object to be cleaned is brought into contact with a hydrophobic cleaning liquid, heated under a temperature condition not lower than the temperature at which moisture is gasified and not higher than the boiling point of the hydrophobic cleaning liquid, and attached to the object to be cleaned. Water in the processing oil is evaporated and removed, and at least a part of the oil and / or surfactant contained in the water-soluble processing oil adhering to the object to be cleaned is dissolved or dispersed in the hydrophobic cleaning liquid. (1) or (1) above, wherein the hydrophobic cleaning liquid obtained by removing the oil and / or surfactant from the hydrophobic cleaning liquid outside the system can be reused as the rinse liquid for the object to be cleaned. Cleaning process described in (2) Method.

(4) The above-described method of contacting the object to be cleaned with the hydrophobic cleaning liquid is a method of immersing the object to be cleaned with water-soluble processing oil in the hydrophobic cleaning liquid, or a method of spraying the hydrophobic cleaning liquid onto the object to be cleaned Alternatively, the cleaning method according to any one of the above (1) to (3), which is a method of flowing a hydrophobic cleaning liquid through an object to be cleaned.
(5) The process of bringing the object to be cleaned into contact with the hydrophobic cleaning liquid and simultaneously heating the object under conditions of temperature and pressure at which moisture is gasified is the process of gasifying the moisture into the cleaning tank into which the object to be cleaned is charged. The hydrophobic cleaning liquid heated to the boiling point of the hydrophobic cleaning liquid at a temperature equal to or lower than the boiling point of the hydrophobic cleaning liquid is heated, and the water to be cleaned is heated to gasify and remove water from the water-soluble processing oil adhering to the cleaning water. The cleaning treatment according to any one of the above (1) to (4), which is a step of dissolving or dispersing at least an oil and / or a surfactant contained in the basic processing oil in a hydrophobic cleaning liquid Method.

(6) Washing processed products that are cut with water-soluble processing oil and to which water-soluble processing oil adheres, or cutting waste that is generated by cutting with water-soluble processing oil and to which water-soluble processing oil adheres, as the object to be cleaned A processing method,
(B) A process of putting an object to be cleaned into a cleaning tank,
(B) The hydrophobic cleaning liquid heated to the boiling point of the hydrophobic cleaning liquid at a temperature at which the moisture is gasified is introduced into the cleaning tank into which the target cleaning object has been charged, and the target object is heated to be cleaned. Gasifying the water in the water-soluble processing oil adhering to the washed product, and at the same time dissolving or dispersing at least a part of the contained oil and / or surfactant in the hydrophobic cleaning liquid;
(C) A purified hydrophobic cleaning liquid obtained by removing at least a part of the oil and / or surfactant in the water-soluble processing oil taken in the hydrophobic cleaning liquid is used in the cleaning process of the object to be cleaned. Process,
The cleaning treatment method according to any one of the above (1) to (5), comprising:

(7) A cleaning method for an object to be cleaned is a cleaning method performed in a sealed system including a cleaning tank and a gas holder,
(A) A step of putting an object to be cleaned into a cleaning tank,
(B) Depressurizing the inside of the cleaning tank with a vacuum pump, discharging the air in the cleaning tank out of the system with the vacuum pump, and then introducing the system gas contained in the gas holder into the cleaning tank;
(C) A temperature at which the water is gasified in the cleaning tank into which the object to be cleaned is charged, and has the ability to dissolve or disperse at least the oil and / or surfactant contained in the water-soluble processing oil. Heated in contact with a hydrophobic cleaning liquid having a partial pressure lower than the partial pressure of water at that temperature, gasifies water-soluble processing oil adhering to the object to be cleaned, and simultaneously adheres to the object to be cleaned A step of dissolving or dispersing at least a portion of the water-soluble processing oil and / or surfactant in a hydrophobic cleaning liquid,
(D) exhausting the vaporized water vapor from the washing tank, condensing and separating through the generated gas condenser, discharging it out of the system as condensed water, and collecting the non-condensed gas in the gas holder;
(E) a step of drying the liquid adhering to the object to be cleaned from which water and / or oil content of the water-soluble processing oil has been removed under reduced pressure by sensible heat of the object to be cleaned;
(F) The residual component dissolved in the hydrophobic cleaning liquid removed by gasifying and removing the water content of the water-soluble processing oil, or the residual component dispersed or remaining as a suspended matter is removed. Obtaining a purified hydrophobic cleaning solution;
(G) a step of drying the hydrophobic cleaning liquid adhering to the object to be cleaned with sensible heat under reduced pressure,
The cleaning treatment method according to any one of the above (1) to (6), comprising:

(8) The above-mentioned hydrophobic cleaning liquid is characterized in that its partial pressure is lower than the partial pressure of water and dissolves at least a part of the remaining components in which the water content of the water-soluble processing oil has evaporated. The cleaning treatment method according to any one of 1) to (7).
(9) The cleaning according to any one of (1) to (8) above, wherein the hydrophobic cleaning liquid contains a paraffin-based hydrocarbon solvent having a boiling point of 120 ° C. or higher, or a halogenated hydrocarbon-based solvent. Processing method.

According to the aspect of the present invention described above, the following effects are brought about.
(A) When processing a cutting product to which the water-soluble processing oil adheres to the next plating or coating process, or cutting chips and chips generated by the cutting process are reused. When processing the said cutting waste and chips in order to use for a melting process for the purpose of utilization, there exist the following problems, but there exists an effect which solves these problems.
・ Hydrophilic cleaning liquid is required to clean the object to which the water-soluble processing oil adheres, and the usable cleaning liquid is limited to hydrophilic glycol-based, N-methylpyrrolidone, or water. However, according to the present invention, a hydrophobic cleaning solution can also be used.
(B) When cleaning with a hydrophilic cleaning liquid, there are the following problems, and it is necessary to take a means for discharging water dissolved in the cleaning solvent out of the system. There is an effect to improve the point.
-The problem is that water adhering to the object to be cleaned reduces the concentration of the cleaning liquid that cleans the processing oil and reduces the cleaning effect.
-Since the boiling point of the cleaning liquid is around 100 ° C. and the temperature of the cleaning liquid is limited, there is a problem that drying may be insufficient in the drying process.
-Since the latent heat of vaporization of the cleaning liquid increases, the amount of heat required for drying increases, which hinders the drying process.

(C) Before the cleaning operation of the liquid to be cleaned is performed, the water in the liquid may evaporate and hydrophobic oil may be applied to the surface of the object to be cleaned. In such a state, there is a problem that the object to be cleaned cannot be easily cleaned with the hydrophilic solvent, but such a problem can be improved.
(D) When a product using water-soluble processing oil is mixed with an object to be cleaned and a processed product using hydrophobic processing oil, a processed product that cannot be cleaned with a hydrophilic water-soluble processing oil cleaning solution is generated. However, this problem can be improved.
In addition, according to the aspect of the present invention, it is possible to reduce the process required for removing the attached liquid, to reduce the floor area of the equipment, and to reduce the cost of removing the attached liquid. In terms of both cost and economy. Since the treatment method of the present invention can be carried out in a closed system, for example, in a nitrogen gas atmosphere, it is excellent in terms of environmental pollution.

The schematic explanatory drawing of the flow sheet of one embodiment of the present invention.

In the present invention, a processed product made of metal, ceramic, or a composite material of metal / ceramic, which is cut and ground with water-soluble processing oil and added with water-soluble processing oil, or cutting with water-soluble processing oil As a typical example, metal, ceramic, or composite material generated by cutting, grinding, etc., and cutting scraps, cutting chips, cutting scraps, abrasive scraps, etc. Of course, it is not limited to these. In the present invention, the cutting process is not limited to the cutting process, and includes a grinding process and a cutting process.
In the present invention, the remaining components of the water-soluble processing oil adhering to the object to be cleaned from which moisture has been removed form a strong film with a force such as van der Waals force, which is difficult to dissolve in a normal solvent. As a drying treatment method that does not form a film of residual components that will be in a state, under the conditions of temperature and pressure at which moisture is gasified, the object to be cleaned with water-soluble processing oil adhered in a hydrophobic liquid solvent, There is a method of heating the object to be cleaned in contact with the hydrophobic cleaning liquid by evaporating the moisture of the water-soluble processing oil adhering to the object to be cleaned, such as by spraying a hydrophobic cleaning liquid onto the object to be cleaned. Adopted. Then, the water in the water-soluble processing oil is evaporated, and at the same time, the oil, surfactant, cutting chips, etc. contained in the water-soluble processing oil are dissolved with a hydrophobic solvent, or washed and removed as a dispersion or floating matter. .

Further, in the present invention, a desired hydrophobic cleaning liquid is used depending on the type of oil lipid attached such as cutting lubricating oil, cutting lubricating oil, etc. of water-soluble processing oil used in cutting or the like and the cleaning method.
Such a hydrophobic cleaning liquid is required not to be substantially gasified in a temperature range in which moisture is gasified, and its partial pressure is lower than a partial pressure of water by a predetermined range, and the water content of the water-soluble processing oil is low. It is selected from hydrophobic solvents that dissolve or disperse the evaporated residue, or remain as suspended matter, which can be removed from the solvent with low energy consumption and reused as a cleaning liquid. Such a hydrophobic cleaning liquid is preferably a solvent having a boiling point of 110 ° C. or higher, which is higher than the boiling point of water, more preferably a non-flammable solvent such as paraffin hydrocarbon solvent or parkrol ethylene having a boiling point of 120 ° C. or higher. Halogenated hydrocarbon solvents can be used. Particularly preferably, as the solvent for the hydrophobic cleaning liquid having a boiling point of 120 ° C. or higher, for example, NS-clean 200 to 300 of Nikko Petrochemical Co., Ltd., a paraffinic hydrocarbon solvent, or HC of Tosoh Co., Ltd. -370, and perchlorethylene, a halogenated hydrocarbon-based non-flammable solvent.

In the present invention, the object to be cleaned is made hydrophobic by immersing the object to be cleaned in a hydrophobic cleaning liquid, spraying the hydrophobic cleaning liquid onto the object to be cleaned, or pouring the hydrophobic cleaning liquid on the object to be cleaned. In contact with an aqueous cleaning solution and processed under conditions such as temperature and pressure for gasifying the water content of the water-soluble processing oil. The temperature of the step of gasifying the water content of the water-soluble processing oil is preferably not higher than the boiling point of the cleaning liquid, and for example, 120 ° C. or higher in an atmospheric pressure atmosphere. Here, the temperature at which moisture is gasified when the object to be cleaned is immersed in a hydrophobic cleaning liquid is determined by washing the water-soluble processing oil adhering to the object to be cleaned with a hydrophobic solvent and then removing the hydrophobic solvent adhering to the object to be cleaned. It is the temperature of the hydrophobic cleaning liquid and / or the temperature of the object to be cleaned necessary for the drying step for drying and completing the cleaning.
That is, the object to be cleaned is brought into contact with the hydrophobic cleaning liquid, heated at a temperature not lower than the temperature at which moisture is gasified and not higher than the boiling point of the hydrophobic cleaning liquid, and the water-soluble processing oil adhering to the object to be cleaned At the same time as evaporating and removing moisture, at least a part of the impurities adhering to the object to be cleaned is dissolved or dispersed in the hydrophobic cleaning liquid, and then the impurity components are removed from the hydrophobic cleaning liquid.

The processed product that is cut by the water-soluble processing oil of the present invention and to which the water-soluble processing oil adheres or the cutting waste that is generated by the cutting by the water-soluble processing oil and to which the water-soluble processing oil adheres is washed as an object to be cleaned. The treatment method preferably includes the following steps (A) to (C).
(B) A process of putting an object to be cleaned into a cleaning tank,
(B) The hydrophobic cleaning liquid heated to the boiling point of the hydrophobic cleaning liquid at a temperature at which the moisture is gasified is introduced into the cleaning tank into which the target cleaning object has been charged, and the target object is heated to be cleaned. Gasifying the water in the water-soluble processing oil adhering to the washed product, and at the same time dissolving or dispersing at least a part of the contained oil and / or surfactant in the hydrophobic cleaning liquid;
(C) A purified hydrophobic cleaning liquid obtained by removing at least a part of the oil and / or surfactant in the water-soluble processing oil taken in the hydrophobic cleaning liquid is used in the cleaning process of the object to be cleaned. Process.

In addition, the cleaning method of the object to be cleaned is a cleaning method performed in a sealed system including a cleaning tank and a gas holder, and even if the hydrophobic solvent used is a flammable solvent, the inside of the sealed system is, for example, nitrogen gas It is preferable to carry out by the system containing the following process (a)-(g) which can maintain the nonflammable atmosphere whose oxygen concentration is below an explosion limit oxygen concentration with this gas.
(A) A step of putting an object to be cleaned into a cleaning tank,
(B) Depressurizing the inside of the cleaning tank with a vacuum pump, discharging the air in the cleaning tank out of the system with the vacuum pump, and then introducing the system gas contained in the gas holder into the cleaning tank;
(C) A temperature at which the water is gasified in the cleaning tank into which the object to be cleaned is charged, and has the ability to dissolve or disperse at least the oil and / or surfactant contained in the water-soluble processing oil. Heated in contact with a hydrophobic cleaning liquid having a partial pressure lower than the partial pressure of water at that temperature, gasifies water-soluble processing oil adhering to the object to be cleaned, and simultaneously adheres to the object to be cleaned A step of dissolving or dispersing at least a portion of the water-soluble processing oil and / or surfactant in a hydrophobic cleaning liquid,
(D) Vaporized moisture vapor is discharged from the cleaning tank, condensed and separated through the generated gas condenser and discharged out of the system as condensed water, and the hydrophobic cleaning liquid is recovered in the cleaning liquid tank and the non-condensed gas is recovered in the gas holder. The process of
(E) a step of drying the liquid adhering to the object to be cleaned from which water and / or oil content of the water-soluble processing oil has been removed under reduced pressure by sensible heat of the object to be cleaned;
(F) The residual component dissolved in the hydrophobic cleaning liquid removed by gasifying and removing the water content of the water-soluble processing oil, or the residual component dispersed or remaining as a suspended matter is removed. Obtaining a purified hydrophobic cleaning solution (purified hydrophobic cleaning solution);
(G) A step of drying the hydrophobic cleaning liquid adhering to the cleaning object under reduced pressure by sensible heat of the cleaning object.

The best mode of the present invention will be described below with reference to the drawings. However, the following description is representative examples of the mode of the present invention, and the present invention is not limited to these descriptions.
A more specific embodiment of the method for cleaning an object to be cleaned according to the present invention includes the following steps.
(A) A step (a) of bringing the object to be cleaned into contact with the hydrophobic cleaning liquid, for example, a step of bringing the object to be cleaned into immersion in the hydrophobic solution for cleaning.
(B) Simultaneously with the step (a), heating is performed under conditions of temperature and pressure for gasifying water in the water-soluble processing liquid adhering to the object to be cleaned, and the water is gasified and removed. A step (b) of removing residual components of the water-soluble processing oil adhering to the washed product;
(C) A step (c) of drying the cleaned object to be cleaned under reduced pressure.

FIG. 1 shows a processed product that is cut by the water-soluble processing oil according to the present invention and to which the water-soluble processing oil adheres, or a cutting waste that is generated by cutting with the water-soluble processing oil and to which the water-soluble processing oil adheres. It is a schematic explanatory drawing of the flow sheet of a series of washing processing methods which wash and dry as a thing to be washed.
In the following description, in particular, the example shown in FIG. 1 is an example of cleaning using aluminum cutting waste generated by cutting an aluminum metal article with water-soluble processing oil as an object to be cleaned according to the present invention. A flow sheet of a preferred apparatus for carrying out the processing method, a cleaning tank 1 having a vacuum (or reduced pressure) drying mechanism, a cleaning liquid tank 2, and a generated gas condenser 23 for cooling and condensing moisture vapor discharged from the cleaning tank 1. , A condensate separator 18, a purified cleaning liquid tank 5, a purifier 7 for separating substances adhering to the object to be cleaned, and a gas holder 11 are provided as main components.
Hereinafter, in accordance with FIG. 1, aluminum cutting waste (hereinafter also referred to simply as aluminum waste).
The main flow regarding the washing and drying operations is explained.

  The aluminum scrap to be processed is input to the cleaning tank 1 from an input port (not shown) for each processing batch. The input amount is adjusted to a preset amount by measurement. When one batch of aluminum scrap is charged into the cleaning tank 1, the charging port is closed and the cleaning tank 1 is sealed. Next, the inside of the cleaning tank 1 is depressurized by the vacuum pump 10, and the air in the cleaning tank 1 is discharged out of the system by the vacuum pump 10, and then the system gas contained in the gas holder 11 (for example, mainly nitrogen gas) ) Is introduced into the washing tank 1, and the washing tank 1 is made equal to the pressure inside the system.

A hydrophobic cleaning liquid (hereinafter also simply referred to as a solvent) in the cleaning liquid tank 2 flows through the cleaning liquid tank 2, the purifier 7, and the purified cleaning liquid tank 5. The solvent is washed with processing oil other than water adhering to the aluminum scraps in the cleaning tank, and the solvent that has been cleaned and contaminated flows into the cleaning liquid tank 2. Next, the solvent is gasified in the purifier 7 and condensed as a purified cleaning liquid in the purified cleaning liquid tank 5. The cleaned dirt is discharged as drainage 27 from the bottom of the purifier 7. The purified cleaning liquid tank 5 is heated by the steam of the purifier 7 and the purified cleaning liquid tank heating heater 25.
The cleaning liquid is preferably heated to a temperature not higher than the boiling point of the cleaning liquid and about 90 to 100 ° C. suitable for cleaning.
The cleaning liquid in the cleaning liquid tank 2 is fed from above the aluminum scrap filling layer 26 filled in the cleaning tank 1 by the operation of the cleaning liquid pump 4, and the filling layer 26 is filled with the cleaning liquid or immersed in the cleaning liquid. The cleaning liquid flows down and the cleaning tank liquid extraction line 16 is adjusted so that the contact condition between the object to be cleaned and the hydrophobic cleaning liquid is in a preferable state. The sent cleaning liquid is heated by the heater 3 to a temperature equal to or higher than the condition for gasifying the water in the cleaning tank.

  On the other hand, the cleaning liquid tank 2 is connected to a purifier 7 via a cleaning liquid pump 4. The purifier 7 is provided with a purifier heater 8, and a certain amount of the cleaning liquid in the cleaning liquid tank 2 is supplied to the purifier 7 and heated and distilled by the heater 8. Separated and removed out of the system. By the function of the purifier 7, soluble oil and fat and suspended matters can be removed from the cleaning liquid returned from the cleaning tank 1 to the purified cleaning liquid tank 5, so that the cleanliness of the cleaning liquid can be maintained constant. . The temperature of the purified cleaning liquid tank 5 also remains attached to the aluminum scrap due to the sensible heat of the aluminum scrap in the subsequent drying step such as the vacuum drying step, the reduced pressure drying step or the ventilation drying step. The cleaning liquid component is set at a temperature higher than the sensible heat that can evaporate without heat treatment of the aluminum scrap. The above-described cleaning with the cleaning liquid is also preferably performed for a certain period of time using the purified cleaning liquid.

Oils and fats, fine suspended matters, etc., which are the distillation residue accumulated in the purifier 7 are separated and taken out from the purifier bottom liquid discharge line 27 to the outside.
The solvent gas gasified by the purifier 7 is condensed in the purified cleaning liquid tank condenser 12 and returned to the purified cleaning liquid tank 5 as a purified cleaning liquid for use.

After the above-described aluminum scrap cleaning operation is performed for a predetermined time, the cleaning liquid circulation pump 4 is stopped, and the cleaning liquid in the cleaning tank 1 is discharged from the lower cleaning tank liquid extraction line 16 to the cleaning liquid tank 2.
In such a cleaning process, it is preferable to use a heated cleaning liquid so that the solvent can be gasified and dried by sensible heat of aluminum scrap.

  Next, in order to evaporate the remaining solvent, the cleaned aluminum scrap seals and insulates the cleaning tank 1, sucks it with the vacuum pump 10, depressurizes the cleaning tank 1, and removes the aluminum scrap. The solvent adhering to the aluminum scraps is evaporated by sensible heat and dried. At this time, the degree of vacuum in the cleaning tank 1 for performing the operation of vacuum drying (or drying under reduced pressure) is preferably about 0.1 Kpa or less. The solvent evaporated and gasified in the cleaning tank 1 is recovered and liquefied in the condenser 12 of the purified cleaning liquid tank 5 and returned to the cleaning liquid tank 2 through the purified cleaning liquid tank 5 as a purified cleaning liquid.

  On the other hand, the generated evaporated gas is cooled and condensed, and the low-concentration solvent gas after the condensation is recovered by the gas holder 11. Here, the gas flowing through the gas holder 11 is stored at a low concentration. After this evaporation step, in order to lower the gas concentration in the cleaning tank 1, the low-concentration solvent gas in the gas holder 11 is circulated to complete the dryness. After the gas in the cleaning tank 1 is recovered, the cleaning tank 1 is shut off from the in-system device. For example, air or nitrogen gas (nitrogen gas in this example) is introduced from the upper part of the cleaning tank 1 to atmospheric pressure and then dried. Aluminum scrap is taken out from the outlet 22 of the cleaning tank.

  A process for removing moisture in the water-soluble processing oil adhered to the aluminum scrap in the cleaning tank 1 described above, a cleaning process for cleaning the aluminum scrap in the cleaning tank with the cleaning liquid, and a cleaning liquid adhered to the object to be cleaned are evaporated and dried. The drying process to be removed can be controlled so that the vapor of the solvent of the cleaning liquid is not discharged to the outside air by using a closed system. In this case, the leakage of the solvent from the cleaning tank 1 and other lines from each line Solvent leakage can be almost completely prevented, which is more environmentally preferable.

Examples of the present invention will be described below, but the present invention is not limited to these examples.
(Example)
Aluminum scrap (dimensions: 0.1 to 20 mm. Oil and fat content in aluminum scrap) recovered as a reuse resource processed using emulsion-type water-soluble processing oil by the flow sheet processing step shown in FIG. The washing tank 1 was filled with about 3 wt% of water and about 10 wt% of water.
The degree of vacuum in the cleaning tank 1 was reduced to 0.1 Kpa, and the air in the tank was discharged out of the system.
Next, using a cleaning liquid composed of a petroleum hydrocarbon solvent (normal paraffin hydrocarbon solvent, boiling point: about 180 ° C.) as a hydrophobic cleaning liquid, each treatment of degreasing and drying was performed as follows.

The cleaning liquid in the purified cleaning liquid tank 5 and the cleaning liquid tank 2 is heated by the purified cleaning liquid tank condenser 12, the purified cleaning liquid tank heating heater 25, and the cleaning liquid tank heater 3 for condensing the vapor from the purifier 7 to obtain the purified cleaning liquid. The purified cleaning liquid tank 5 was maintained at about 90 ° C., and the cleaning liquid tank 2 was maintained at about 110 ° C.
The cleaning liquid passed through the cleaning liquid tank 2 and the pump 4 is fed into the upper part of the aluminum scrap filling layer 26 in the cleaning tank 1, and the cleaning liquid is supplied to the filling layer 26 in the cleaning tank 1, so as to be in an immersion state. The temperature of the aluminum scrap was raised, the water of the water-soluble processing oil of the aluminum scrap was gasified, and the water was discharged out of the tank via the line 17. At the same time, the water-soluble processing oil was dissolved or washed as a suspended matter. The gasified moisture discharged from the line 17 to the outside of the tank was discharged out of the system through a generated gas condenser 23 for cooling and condensing moisture vapor and a condensed water separator 18. The cleaning liquid is circulated in the above-described flow for about 10 minutes. After cleaning and heating the aluminum scrap, the cleaning liquid is stopped from circulating, and the liquid in the cleaning tank 1 is transferred to the cleaning liquid tank 2 via the cleaning tank liquid extraction line 16. Discharged.

  Subsequently, the purified cleaning liquid is fed from the upper part of the cleaning tank 1 through the purified cleaning liquid tank 5, the purified cleaning liquid pump 6, and the purified cleaning liquid supply line 14, and the cleaning liquid is circulated in the filling layer 26 in the cleaning tank 1 to be filled. While raising the temperature of the aluminum waste in the layer 26, the adhesion liquid of the aluminum waste was rinse-washed, the cleaning liquid was allowed to flow down from the cleaning tank 1, and discharged to the purified cleaning liquid tank 5 through the cleaning tank rinse liquid extraction line 28. After washing with the rinse solution for 5 minutes, the supply of the rinse solution was stopped.

Next, in order to evaporate and dry the solvent remaining in the aluminum scraps by a vacuum drying operation, the cleaning tank 1 is insulated, sucked by the vacuum pump 10, and sensible heat of the aluminum scraps in the cleaning tank 1 makes aluminum The solvent adhering to the scraps was evaporated and dried. The solvent adhering to the aluminum scrap after the drying operation was a negligible value. The solvent evaporated and gasified in the cleaning tank 1 was recovered and returned to the purified cleaning liquid tank 5 as a cleaning liquid that was liquefied and purified by the condenser 12 of the purified cleaning liquid tank 5.
By such a method, the fats and oils and the water | moisture content which adhered to the aluminum scrap before the said process were able to be removed.

Dispose of scraps and other waste generated as a useful resource in order to use the water-soluble processing oil for machining and coating processing, or for cutting with water-soluble processing oil. It is necessary to remove the water-soluble processing oil adhering to the workpiece and the water-soluble processing oil adhering to the cutting waste so that it can be used in the melting process of the cutting waste for reuse. However, according to the cleaning method of the present invention, various problems that occur when water-soluble processing oil is cleaned and removed by conventional methods can be solved.
In addition, since the cleaning method of the present invention can be a closed system, energy consumption is greatly reduced, generation of CO ₂ , NO _x , and SO _x that cause environmental pollution is further suppressed. The risk of dust explosion can be reduced and removed efficiently.
Further, according to the present invention, the floor area of the equipment required for removing the adhering liquid, the equipment cost, and the adhering liquid removing cost can be reduced, which is excellent in both environmental measures and economy. As described above, the present invention is useful as a cleaning method for a processed product processed with a water-soluble processing oil, and as a cleaning method for cutting waste generated by cutting with a water-soluble processing oil and adhering to the water-soluble processing oil. It is.

1: cleaning tank, 2: cleaning liquid tank,
3: Liquid tank heater, 4: Cleaning liquid pump,
5: Purified cleaning liquid tank, 6: Purified cleaning liquid pump,
7: Purifier, 8: Purifier heater,
9: Purifier generated solvent gas 10: Vacuum pump
11: Gas holder, 12: Condenser,
13: Cleaning liquid supply line, 14: Purified cleaning liquid supply line,
15: heater, 16: washing tank liquid extraction line,
17: Cleaning tank generated gas extraction line, 18: Condensate separator,
19: Cleaning liquid heat exchange circulation line, 20: Condensed water,
21: Air or nitrogen gas introduction line,
22: Cleaning line, vacuum-dried aluminum scrap extraction line,
23: Generated gas condenser, 24: Heating heater for washing tank,
25: Heating heater for purified cleaning solution tank, 26: Packed bed in cleaning tank,
27: Purifier bottom liquid discharge line. 28: Cleaning tank rinse liquid extraction line.
29: Air release line

Claims (9)

  A processed product that is cut with water-soluble processing oil and to which water-soluble processing oil adheres, or cutting waste that is generated by cutting with water-soluble processing oil and to which water-soluble processing oil adheres is used as a cleaning method. In addition, the object to be cleaned is brought into contact with the hydrophobic cleaning liquid, and at the same time, the object to be cleaned is cleaned by heating under conditions of temperature and pressure at which water in the water-soluble processing oil is gasified. Processing method.   It is a method of cleaning processed products that are cut by water-soluble processing oil and to which water-soluble processing oil adheres, or cutting waste that is generated by cutting with water-soluble processing oil and to which water-soluble processing oil adheres, as an object to be cleaned. The temperature of the water-soluble processing oil adhering to the object to be cleaned is gasified, and has the ability to dissolve or disperse at least the oil and / or surfactant contained in the water-soluble processing oil. Heated in contact with a hydrophobic cleaning liquid having a partial pressure lower than the partial pressure of water at the temperature, and gasified water of the water-soluble processing oil adhering to the object to be cleaned and at the same time adhering to the object to be cleaned A cleaning method comprising: removing or washing at least an oil component and / or a surfactant of a water-soluble processing oil by dissolving or dispersing in a hydrophobic cleaning solution.   A processed product that is cut with water-soluble processing oil and to which water-soluble processing oil adheres, or cutting waste that is generated by cutting with water-soluble processing oil and to which water-soluble processing oil adheres, is treated as a cleaning object. A water-soluble processing oil adhering to the object to be cleaned, which is brought into contact with the hydrophobic cleaning liquid and heated under temperature conditions not lower than the temperature at which moisture is gasified and not higher than the boiling point of the hydrophobic cleaning liquid. Water is removed by evaporation, and at least part of the oil and / or surfactant contained in the water-soluble processing oil adhering to the object to be cleaned is dissolved or dispersed in the hydrophobic cleaning liquid, and then the oil is removed. The hydrophobic cleaning liquid obtained by removing the surfactant from the hydrophobic cleaning liquid out of the system can be reused as a rinse liquid for the object to be cleaned. Cleaning method.   The above-described method of contacting the object to be cleaned with the hydrophobic cleaning liquid is a method of immersing the object to be cleaned with water-soluble processing oil in the hydrophobic cleaning liquid, a method of spraying the hydrophobic cleaning liquid onto the object to be cleaned, The cleaning method according to any one of claims 1 to 3, wherein a hydrophobic cleaning liquid is allowed to flow through the cleaning object.   At the same time that the object to be cleaned is brought into contact with the hydrophobic cleaning liquid and heated under conditions of temperature and pressure at which moisture is gasified, the temperature at which the moisture is gasified in the cleaning tank into which the object to be cleaned is charged. A water-soluble processing oil is supplied by feeding a hydrophobic cleaning liquid heated below the boiling point of the hydrophobic cleaning liquid and heating the object to be cleaned to gasify and remove water from the water-soluble processing oil adhering to the object to be cleaned. 5. The cleaning treatment method according to claim 1, wherein at least the oil and / or surfactant contained in is dissolved or dispersed in a hydrophobic cleaning solution. A processed product that is cut with water-soluble processing oil and to which water-soluble processing oil adheres, or cutting waste that is generated by cutting with water-soluble processing oil and to which water-soluble processing oil adheres, is treated as a cleaning object. There,
(B) A process of putting an object to be cleaned into a cleaning tank,
(B) The hydrophobic cleaning liquid heated to the boiling point of the hydrophobic cleaning liquid at a temperature at which the moisture is gasified is introduced into the cleaning tank into which the target cleaning object has been charged, and the target object is heated to be cleaned. Gasifying the water in the water-soluble processing oil adhering to the washed product, and at the same time dissolving or dispersing at least a part of the contained oil and / or surfactant in the hydrophobic cleaning liquid;
(C) A purified hydrophobic cleaning liquid obtained by removing at least a part of the oil and / or surfactant in the water-soluble processing oil taken in the hydrophobic cleaning liquid is used in the cleaning process of the object to be cleaned. Process,
The cleaning treatment method according to claim 1, comprising: The cleaning method of the object to be cleaned is a cleaning method performed in a sealed system including a cleaning tank and a gas holder,
(A) A step of putting an object to be cleaned into a cleaning tank,
(B) Depressurizing the inside of the cleaning tank with a vacuum pump, discharging the air in the cleaning tank out of the system with the vacuum pump, and then introducing the system gas contained in the gas holder into the cleaning tank;
(C) A temperature at which the water is gasified in the cleaning tank into which the object to be cleaned is charged, and has the ability to dissolve or disperse at least the oil and / or surfactant contained in the water-soluble processing oil. Heated in contact with a hydrophobic cleaning liquid having a partial pressure lower than the partial pressure of water at that temperature, gasifies water-soluble processing oil adhering to the object to be cleaned, and simultaneously adheres to the object to be cleaned A step of dissolving or dispersing at least a portion of the water-soluble processing oil and / or surfactant in a hydrophobic cleaning liquid,
(D) Vaporized moisture vapor is discharged from the cleaning tank, condensed and separated through the generated gas condenser and discharged out of the system as condensed water, and the hydrophobic cleaning liquid is recovered in the cleaning liquid tank and the non-condensed gas is recovered in the gas holder. The process of
(E) a step of drying the liquid adhering to the object to be cleaned from which water and / or oil content of the water-soluble processing oil has been removed under reduced pressure by sensible heat of the object to be cleaned;
(F) The residual component dissolved in the hydrophobic cleaning liquid removed by gasifying and removing the water content of the water-soluble processing oil, or the residual component dispersed or remaining as a suspended matter is removed. Obtaining a purified hydrophobic cleaning solution;
(G) a step of drying the hydrophobic cleaning liquid adhering to the object to be cleaned with sensible heat under reduced pressure,
The cleaning treatment method according to claim 1, comprising:   The hydrophobic cleaning liquid has a partial pressure lower than the partial pressure of water, and dissolves at least a part of the remaining components in which water in the water-soluble processing oil has evaporated. The cleaning treatment method according to any one of the above.   The cleaning method according to any one of claims 1 to 8, wherein the hydrophobic cleaning liquid contains a paraffin-based hydrocarbon solvent or a halogenated hydrocarbon-based solvent having a boiling point of 120 ° C or higher.

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