JPH034898A - Method and device for cleaning - Google Patents

Abstract

PURPOSE:To allow the optimum cleaning of various materials such as fashion clothings, metallic parts and IC boards having much fat and oil deposition and delicate plastic materials stuck with very slight contaminations by pulverizing and dispersing an insoluble org. solvent into perfluorocarbons which are inert liquids to form a cleaning bath. CONSTITUTION:The insoluble org. solvent, such as perchloroethylene, 1.1.1 trichloroethane or methylene chloride, is pulverized and dispersed into the perfluorocarbons, such as perfluorohexane, which are the inert liquids to form the cleaning bath. The novel cleaning method to control the detergency for clothing or metallic parts, IC boards, etc., by this cleaning bath is adopted, by which the detergency equiv. to the conventional fluorocarbon solvent is assured and the problem of the breakdown of the ozonosphere which is the vital problem of the fluorocarbon solvent is solved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cleaning method and apparatus for cleaning various items such as clothing, metal parts, and RC boards using an organic solvent.

(Prior Art) First, a conventional so-called dry cleaning process in which clothes are washed using an organic solvent will be described below.

Conventional dry cleaners use 1.1.1 trichloroethane, perchlorethylene, Freon 113, Freon 11,
Five types of organic solvents, including turpentine (petroleum-based), are used as cleaning agents. Here, a dry cleaning process other than a turpentine will be outlined using FIG. 3 showing a conventional dry cleaning system.

First, the clothing 2 is put in through the door 1, and the door 1 is closed to start operation. Generally, the steps proceed in the following order.

(2) Pump up the solvent 4 from the solvent tank 3 through the pulp 5 with the pump 6, and feed the necessary amount of the solvent 4 into the processing tank 10 through the path consisting of the pulp 7 and the filter 8 or the path consisting of the pulp 9.

■, Slowly rotate the processing drum 11 and pour the solvent 4 into the processing tank 1.
Clothes 2 are washed by circulation through a circuit consisting of a button trap 12, a valve 13, a pump 6, a valve 7, a filter 8, or a valve 9.

(2) The liquid is drained through the processing tank 10, button trap 12, valve 13, pump 6, valve 14, and distiller 15, and then the processing drum 11 rotates at high speed to centrifuge the solvent 4 in the clothing 2. Drain in the same way.

(2) Repeat the steps in (2) and (2) above.

(2) The liquid is drained into the solvent tank 3 through the path of the processing tank IO, the button trap 12, the valve 13, and the valve 5, and then the processing drum 11 rotates at high speed to centrifugally separate the solvent 4 in the clothing 2.
Drain.

■Slowly rotate the processing drum 11 again, and the fan 16,
Air is circulated in the direction of arrow 20 between a recovery air duct 19 consisting of an air cooler 17 and an air heater 18 and a processing tank 10 to dry the clothes 2. The solvent gas evaporated from the clothing 2 is condensed in the air cooler 17, enters the water separator 22 through the recovery path 21, and enters the Tallinn tank 24 through the solvent pipe 23.

② When drying is completed, the dampers 25 and 26 open as shown by the broken lines, taking in fresh air from the damper 25, and exhausting uncondensed solvent gas that cannot be recovered by the air cooler 17 from the damper 26, eliminating the solvent odor in the clothing 2. Deodorize.

The solvent 4 that entered the distiller 15 in the process of (2) and (2) evaporates and is condensed and recovered in the condenser 27, passes through the water separator 22 and solvent piping 23, enters the Tallinn tank 24, and flows from the overflow partition plate 28. , return to solvent tank 3. In addition,
The water separated by the water separator 22 is discharged to the outside of the system through a water pipe 29.

Next, the dry cleaning process using turpentine (petroleum solvent) will be outlined using FIGS. 4 and 5.

Turpendry cleaners usually have a treatment tank 1 shown in Figure 3.
A cleaning and deliquing tank 100 shown in FIG. 4 similar to the part 0,
It is divided into a drying tank 200 (called a tumbler) shown in FIG.

In the cleaning and deliquing tank 100, the cleaning process using another solvent described above and the same processes as the above-mentioned (1), (2) and (2) are performed to complete the entire process. Incidentally, in turpentine dry cleaning, distillation is usually not performed, but in many cases, the filter 8a is filled with a fatty acid adsorbent such as porous alumina or a decolorizing agent such as activated carbon to purify the solvent 4.

Next, the clothing 2 after the liquid removal is taken out from the door 1 and placed into the processing tank 10a through the tumbler door 1a shown in FIG. In the tumbler, outside air 20a is taken in through the entrance hole 9a by the fan 16, heated by the air heater 18, and sent into the processing tank 10a.

The solvent 4 in the clothing 2 evaporates and is discharged outside the system (outdoors) from the exit duct 19b, completing the drying.

The dry cleaning process using various solvents has been outlined above, but the current dry cleaners that use these solvents are capable of cleaning with a single solvent, cleaning with a single solvent,
A dry method is used.

Table 1 compares typical physical properties of currently widely used solvents. Table 2 also shows the dry cleaning characteristics caused by the typical physical properties of the solvents shown in Table 1.
This is a comparison of restrictions, drawbacks, etc. Now, due to the above-mentioned physical properties, in order to respond to the recent diversification of clothing materials, processing, and forms, there are two types of dry cleaners: perchlorethylene dry cleaner and Freon 113 dry cleaner, and 1.1.1 trichloroethane dry cleaner. 3 with cleaner added
Different types of dry cleaners will be required, and for cleaning companies, it will require an increase in purchasing funds, space, equipment capacity, etc.
This created an extremely heavy burden, as maintenance work became more complicated.

Table 1 As a means to solve these problems, the present inventors have proposed in Japanese Unexamined Patent Publication No. 154698/1983 a tank capable of storing at least two mutually soluble solvents, respectively. By providing a single dry cleaner with the functions of supplying each solvent to the processing tank and the function of purifying each solvent alone or a mixture of each solvent, it is possible to supply different solvents depending on the type of clothing. A proposal is made for the solvents listed in Table 1 that are currently commercially available as dry cleaning solvents, regarding the method of cleaning by using different types of solvents or by mixing two or more solvents in arbitrary proportions in order to obtain intermediate physical properties of each solvent. did.

The above is a conventional cleaning method using an organic solvent for clothing.

Next, a conventional cleaning method using an organic solvent for cleaning objects other than clothing, such as metal parts or IC boards, will be outlined using FIG. 6. In FIG. 6, the cleaning tank 101 consists of an ultrasonic tank 102 and a steam tank 1.03, and a cooling coil 105 made of cooling water is wound in the upper part of the cleaning tank 101 in a coil shape to condense and recover the solvent vapor 104'. It's dark. Further, a cleaning solvent 104 is stored in the ultrasonic bath 102, and an ultrasonic vibrator 106 is placed at the bottom of the bath. The cleaning solvent 104 in the ultrasonic tank 102 is circulated through a circuit including a valve 107 , a pump 108 , a filter 109 , and the ultrasonic tank 102 .
It is designed to flow down to 03.

The cleaning solvent 104 in the evaporation tank 103 is heated by the heater 111 and boils, becoming solvent vapor 104' and flowing into the cleaning tank 1.
After reaching the height of the cooling coil 105 of No. 01, it is cooled and re-condensed by the same cooling coil 105, and the cleaning tank 101 is
The water flows into the water separator 113 via the tray 112 of the water.

In the water separator 113, the cleaning solvent 104 and water 114 are separated due to the difference in specific gravity, and the water 114 is discharged to the outside of the system through a drain pipe 115. Meanwhile, the cleaning solvent 104 is returned to the ultrasonic bath 102 through a solvent return pipe 116. In addition, in the figure, 117 is a liquid supply valve, and 118 and 119 are liquid drain valves.

Next, a cleaning procedure for the cleaning tank 101 having the above configuration will be outlined.

The object 131 to be cleaned, such as a metal part or an IC board, is normally stored in a wire mesh section 133 attached to a lifting fitting 132, and is first immersed in a cleaning solvent 104 in an ultrasonic bath 102 to undergo so-called ultrasonic cleaning. It will be done for the required time.

Next, the wire mesh section 133 that accommodates the items to be washed 131 is placed in the ultrasonic bath 1.
02 and the solvent 104 in the adjacent thin air tank 103
While suspended in the gas phase between the liquid level and the cooling coil 105, cleaning is performed for a required period of time by utilizing the fact that the solvent vapor 104' is cooled and recondensed on the surface of the object 131 to be washed.

When the above steps are completed, the wire mesh portion 133 containing the object to be washed 131 is pulled up to the outside of the washing tank LotO, and the washing is completed. In this case, the solvent 104 slightly attached to the object 131 to be washed quickly evaporates into the atmosphere, and the drying of the object 131 to be washed is completed.

The above is an overview of cleaning methods for metal parts or RC boards, etc., but the a-containing solvents used for these include trichlorethylene, 1.1.1 trichloroethane, methylene chloride, and Freon 113. The amount of Freon 113 used in delicate parts such as circuit boards is rapidly increasing.

(Problems to be Solved by the Invention) By the way, dry cleaners and equipment for cleaning metals, etc., which use these solvents have various pollution problems regardless of the solvent used. Among them, CFC-113, which has been rapidly increasing in recent years due to its least toxicity, has very stable properties, so the gas that escapes into the atmosphere does not decompose easily, and ultimately it can destroy the earth. Gradual production restrictions will be implemented on an international scale starting in 1989, as it will destroy the surrounding ozone tank.

Under these circumstances, DuPont briefly considered Freon 132b as an alternative to Freon 113, but it can no longer be considered a substitute due to its excessive dissolving power and high toxicity. Against this background, the dry cleaning industry, IC industry association, etc. are currently considering measures to improve the recovery rate of Freon 113 and reduce its consumption, since there is virtually no easily decomposable, low-boiling solvent that can replace Freon 113. This is the current situation.

Therefore, in order to select a new cleaning solvent that does not destroy the ozone layer, the present inventors conducted intensive research on the basic characteristics of cleaning agents, and investigated the organic solvents currently produced for industrial or in-house use. By expanding the scope of our research to include solvents that have not been considered as cleaning agents in the past, and by discovering and adopting new cleaning agents, we have developed a useful cleaning method that is thought to cause almost no pollution. developed.

(Means for Solving the Problems) That is, the present invention provides an insoluble organic solvent such as perchloroethylene, 1.1.1 trichloroethane, methylene chloride, etc. in perfluorocarbons such as perfluorohexane, which is an inert liquid. The cleaning bath is formed by dispersing the liquid into fine particles, and this is used as a means to solve the problem.

The present invention also provides a liquid stirring and dispersion device having at least one of an ultrasonic vibrator, a stirring blade, and a centrifugal pump, and a cleaning bath formed by finely dispersing an insoluble organic solvent in an inert liquid using the same device. It is equipped with a washing tank that is supplied to the washing tank to wash clothing, metal parts, RC boards, etc., and is used as a means to solve the problem.

(Function) In the present invention, perfluorocarbons that are known as inert liquids and have low toxicity and do not cause ozone layer depletion, such as perfluorohexane, are mixed with organic solvents that are insoluble therein, such as perchloroethylene, 1.1・By micronizing and dispersing 1-trichloroethane, methylene chloride, etc., and changing the density of the microparticles (specifically, by changing the mixing ratio of perfluorocarbons and organic solvents), it can be used for clothing, metal parts, and RC boards. By adopting a new cleaning method that controls the cleaning power of fluorocarbons, it ensures the same cleaning power as conventional fluorocarbon solvents, and at the same time fundamentally solves the problem of ozone layer destruction, which is a fatal problem with fluorocarbon solvents. It is.

(Example) Hereinafter, the present invention will be explained with reference to embodiments on the field.

First, the embodiment device which is the basis of the present invention will be explained with reference to FIG. 1. The main differences between FIG. 1 and FIG. 3 (conventional method) are: 3 are combined into one solvent tank 3, which is equipped with an ultrasonic vibrator 30 and a solvent stirring blade 31;
■ In Figure 3, the washed solvent is transferred to the distiller 15 in the processing tank 10,
Button trap 12, valve 13, pump 6, valve 1
In Fig. 1, the washed solvent is first sent to the solvent specific gravity separation tank 32, where it is separated by specific gravity into an inert liquid 4'' and a cleaning solvent 4'. At the same time, the active liquid 4'' is returned to the solvent tank 3 as is.
Since the cleaning solvent 4' needs to remove dirt components, it is sent to the distiller 15, and the solvent evaporated by distillation is returned to the solvent tank 3 via the condenser 27 and the water separator 22. In more detail, the processing tank 10 and filter 8
The difference from FIG. 1 is that an ultrasonic transducer 30 is also attached to the tank.

The main differences between the present invention and the conventional method have been described above; however,
To make the content of the present invention clearer, typical cleaning,
The drying and solvent regeneration process will be explained step by step.

As mentioned above, the feature of the present invention is that the cleaning solvent insoluble in the inert liquid is made into fine particles and uniformly dispersed, and the density of the fine particles (specifically, the mixing ratio of the inert liquid and the cleaning solvent) is controlled. One of the main objectives is to control the cleaning power by changing the cleaning power, and thereby to obtain the same cleaning power as the conventional Freon 113.

Here, a case will be described in which perchloroethylene is used as a cleaning solvent for making perfluorohexane into fine particles, which is a representative inert liquid and has the physical properties shown in Table 3.

Table 3■ First, before operation, add perfluorohexane/perchlorethylene two-phase liquid (80/20vol.
%) are stirred and mixed by a solvent stirring blade 31 and an ultrasonic vibrator 30, and perchloroethylene is made into fine particles and uniformly dispersed in perfluorohexane to form a solvent 4.

■ Load clothing 2 through door 1, close door 1, and start operation.

(2) The solvent 4 is pumped up from the solvent tank 3 through the valve 5 with the pump 6, and the required amount of the solvent 4 is sent into the processing tank 10 through the path consisting of the valve 7 and the filter 8, or the path consisting of the valve 9.

■ Slowly rotate the processing drum 11 and pour the solvent 4 into the processing tank 1.
Clothes 2 are washed by circulation through a circuit consisting of a button trap 12, a valve 13, a pump 6, a valve 7, a filter 8, or a valve 9. During this time, the treatment tank 10 and filter 8
The ultrasonic transducer 30 attached to the is activated.

■ The liquid is drained through the processing tank 10, button trap 12, valve 13, pump 6, valve 14, and solvent specific gravity separation tank 32, and then the processing drum 11 rotates at high speed to centrifugally separate the solvent 4 in the clothing 2. , drain as well.

■ Repeat the above steps ■, ■, and ■ as necessary.

■ Slowly rotate the processing drum 11 again and turn the fan 16,
Air is circulated in the direction of arrow 20 between a recovery air duct 19 consisting of an air cooler 17 and an air heater 18 and a processing tank 10 to dry the clothes 2. The solvent gas (mixed gas of perfluorohexane and perchloroethylene) evaporated from the clothing 2 is condensed in the air cooler 17, enters the water separator 22 through the recovery path 21, and enters the solvent tank 3 through the solvent piping 23. .

■ When drying is completed, dampers 25 and 26 open as shown by the broken lines, fresh air is taken in from damper 25, and damper 2
The uncondensed solvent gas that cannot be recovered by the air cooler 17 is exhausted from the air cooler 17, and the solvent odor in the clothing 2 is deodorized.

■ The solvent 4 that entered the solvent separation tank 32 in the process of item 0 is converted into the original inert liquid (perfluorohexane) 4'' and the cleaning solvent (perchlorethylene) 4' while passing between the partition walls 35. The former is separated by specific gravity, and the former goes directly to the solvent tank 3, and the latter goes to the distiller 15, where it is distilled and goes to the solvent tank 3 via the condenser 27 and the water separator 22.

Note that the water separated by the water separator 22 is discharged to the outside of the system through a water pipe 29.

Although typical examples of the present invention have been described in detail above,
This is an example in which a tank dedicated to perfluorohexane and perchloroethylene was used as the sole solvent to replace Freon 113. However, this new cleaning method using perfluorohexane and perchloroethylene was developed by the present inventors in ``2'' disclosed in JP-A-61-154698.
types of solvents, such as perchlorethylene and Freon 113
It can also be applied to a method in which the machine is built into one machine and used depending on the type of clothing.

FIG. 2 is based on the assumption that a cleaning solvent (perchlorethylene) 4' as a first solvent is made into fine particles and uniformly dispersed in perfluorohexane as a second solvent. After introducing the washed solvent 4 from the treatment tank 10 to the solvent specific gravity separation tank 32, if necessary, perchlorethylene is made into fine particles and uniformly dispersed in a cleaning solvent (perchlorethylene) 4' or perfluorohexane. This figure shows the flow up to the point where the solvent 4 is arbitrarily sent to the processing tank 10.

Now, in Fig. 2, the solvent 4 after washing is sent to a solvent specific gravity separation tank 32, and after being separated by specific gravity, an inert liquid (perfluorohexane) 4'' is produced in a tank 3 exclusively for perfluorohexane.
6, the cleaning solvent (perchloroethylene) 4' is vaporized Wh
15, capacitor 27, moisture M,? It enters the perchlorethylene exclusive tank 37 via S22. Further, 40 is a storage tank for a solvent 4 in which perfluoroethylene is made into fine particles and uniformly dispersed in perfluorohexane, and a solvent stirring blade 41 and an ultrasonic vibrator 3 are used at all times during operation of the dry cleaner main body.
Mix solvent 4 by stirring. When the solvent 4 is consumed, the valves 38, 39 are each opened for a preset time to replenish the depleted bone.

Therefore, when a program for cleaning with perchlorethylene is selected, the cleaning solvent (perchlorethylene) 4' is supplied from the perchlorethylene dedicated tank 37 to the processing tank 10 via the valve 45, pump 46, and check valve 47. Ru. On the other hand, when cleaning with the solvent 4 in which perfluoroethylene is made into fine particles and uniformly dispersed in perfluorohexane, the valve 42, pump 43, and check valve 44 are used.

The above is the case where the present invention is applied to a dry cleaner.

Next, a case where the present invention is applied to the conventional cleaning tank 101 using an organic solvent for cleaning metal parts or IC boards, etc. shown in FIG. 6 will be described. First, a cleaning solution in which fine particles of perchlorethylene are uniformly dispersed in perfluorohexane, which is one of the embodiments of the present invention, is used in a conventional cleaning tank 101 shown in FIG. 6 using a conventionally used solvent. be,
For example, you can completely replace Freon 113,
The cleaning process in this case is completely the same as the conventional one.

That is, in the cleaning tank 101, the built-in ultrasonic transducer 1
By stirring and mixing the cleaning liquid 104 by the cleaning liquid 104 and the pump 108, it is possible to maintain the uniform dispersion effect of perchlorethylene into fine particles in perchlorohexane, which is a feature of the present invention. In addition, in the sudden tank 103, the completely uniformly mixed perfluorohexane and perchlorethylene vapor condense on the surface of the object to be washed 131 at the micron level, so that there is no perfluorohexane in the liquid phase.

Furthermore, in the above embodiments, for convenience of explanation, perfluorohexane was used as an example of perfluorocarbons, and perchloroethylene was used as an organic solvent insoluble therein, but the present invention is not limited to these, and e.g. Examples of the former include perfluoroalkanes, perfluorocycloalkanes, aromatic perfluorocarbons, etc., and examples of the latter include chlorinated hydrocarbon solvents such as 1.1.1 trichloroethane, methylene chloride, trichloroethylene, etc. A wide range of combinations can be considered, including alcohol solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and butyl alcohol, and ketones such as acetone and methyl ethyl ketone (MEK).

That is, the feature of the present invention is that a solvent insoluble in the inert liquid is made into fine particles and uniformly dispersed, and the cleaning power is increased by changing the density of the fine particles (specifically, the mixing ratio of the two liquids). It's about trying to control it. Although the example in which a single solvent was used as the organic solvent insoluble in the inert liquid was not explained, for example, perchlorethylene and 1.1.
1. The mixed solution of trichloroethane may be made into fine particles and dispersed. Similarly, two or more types of inert liquids may be mixed and used, and it is within the scope of the present invention to mix a plurality of liquids in each group, that is, an inert liquid and an organic solvent insoluble therein. belongs to

(Effects of the Invention) As explained in detail above, the present invention forms a cleaning bath by finely dispersing an insoluble organic solvent in perfluorocarbons, which is an inert liquid. Because the dissolving power (dissolving power) can be adjusted, it can be used for cleaning clothes ranging from practical clothes to fashion clothes that use a lot of recent delicate materials, and for cleaning metal parts and IC boards, from items with a large amount of attached oil and fat. It is possible to optimally clean even delicate plastic materials that are contaminated with dirt. In addition, the inert liquid that disperses organic solvent particles and is equivalent to the sea does not dissolve dirt due to its characteristics (and is easily separated from the cleaning solvent by gravity separation method, so it cannot be recycled by distillation or other means. Significant energy savings can be achieved without the need.

[Brief explanation of the drawing]

Fig. 1 is a flow sheet of a dry cleaner showing a first embodiment of the present invention, Fig. 2 is a flow sheet of a solvent regeneration section in a dry cleaner showing a second embodiment of the present invention, and Fig. 3 is a flow sheet of a conventional dry cleaner. Flow sheet showing an example of
The figure shows a piping diagram showing the cleaning and deliquifying equipment of a conventional petroleum-based dry cleaner. Figure 5 is a sectional view showing the drying equipment of a conventional petroleum-based dry cleaner. Figure 6 shows a conventional oil-based dry cleaner. It is a flow sheet showing a cleaning device for cleaning. Explanation of the main parts of the diagram 3-? Container tank 4 - Solvent 4' - Cleaning solvent 4'' - Inert liquid 6 - Pump 10 - Processing tank 3〇 - Ultrasonic vibrator 31 - Solvent stirring blade 32 - - Solvent specific gravity separation tank

Claims (2)

[Claims] (1) Add perfluorocarbons such as perfluorohexane, which is an inert liquid, to perchloroethylene, 1.1.
A cleaning method characterized by forming a cleaning bath by dispersing an insoluble organic solvent such as 1-trichloroethane or methylene chloride into fine particles. (2) A liquid stirring and dispersing device having at least one of an ultrasonic vibrator, a stirring blade, and a centrifugal pump, and a cleaning bath formed by finely dispersing an insoluble organic solvent in an inert liquid is supplied by the device. 1. A cleaning device comprising a cleaning tank for cleaning clothes, metal parts, IC boards, etc.