JPH02169762A - Dry cleaning process - Google Patents

Abstract

PURPOSE:To accomplish cleaning of a variety of clothing using a single dry cleaner by making cleanings using a mixture of 1,1-dichloro-2,2,2-trifluoroethane, perfluorocarbon and tetrachlorodifluoroethane at desired proportions. CONSTITUTION:1,1-dichloro-2,2,2-trifluoroethane (CFC 123) is held into an exclusive solvent tank 3a, while perfluorocarbon and tetrachlorodifluoroethane (CFC 112) are mixed at a specified ratio and the resulting mixture is held into a second solvent tank 3, and furthermore, exclusive valves 5a, 5 are provided. Thence, the respective solvents are pumped into a treatment tank 10, a treatment drum 11 is rotated to circulate the resulting mixed solvent to clean a clothing 2. After the cleaning, the solvent is discharged into a still 15, while the solvent gas evaporated from the clothing 2 is condensed through an air cooler 17 and allowed to flow into the still 15. The solvent thus collected in said still 15 is then distilled via a condenser 27 through water separator 22, 22a into a low-boiling solvent 4a and a high-boiling solvent 4, which are then recovered into the tanks 3a and 3, respectively.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention uses 1,1-dichloro-2,2゜2-trifluoroethane (Freon 123), perfluorocarbon and tetrachlorodifluoroethane (Freon 112) as cleaning solvents. ) in one apparatus.

(Prior art) In conventional dry cleaners, Ll, 1-lychloroethane, perchlorethylene, Freon 113, Freon 11
Five types of organic solvents are used as cleaning agents: , turpentine (petroleum-based).

A system diagram of a conventional dry cleaner is shown in FIG.

Using the same figure, the dry cleaning process other than the turpentine will be outlined. First, put clothing 2 through door 1, and then put clothing 2 through door 1.
After closing and starting operation, the steps generally proceed in the following order.

(2) Pump up the solvent 4 from the solvent tank 3 through the valve 5 with the pump 6, and send the necessary amount of the solvent 4 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.
0. Clothes 2 are washed by circulation through a circuit consisting of button trap 12, valve 13, pump 6, valve 7, filter 8, or 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 centrifugally separate the solvent 4 in the clothing 2. Drain in the same way.

■Repeat the steps of ■ and ■ above.

(3) The liquid is drained into the solvent tank 3 through the path of the processing tank 10, button trap 12, valve 13, and valve 5, and then the processing drum 11 rotates at high speed to centrifuge the solvent 4 in the clothing 2 and drain it. .

■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, and fresh air is taken in from the damper 25, and uncondensed solvent gas that cannot be recovered by the air cooler 17 is exhausted from the damper 26, eliminating the solvent odor in the clothing 2. Deodorize.

(2) The solvent 4 that entered the distiller 15 in the step (2) evaporates, is condensed and recovered in the condenser 27, passes through the water separator 22 and the solvent pipe 23, enters the Tallinn tank 24, and passes through 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 are usually divided into a cleaning/deliquency tank 100 shown in FIG. 4, which is similar to the processing tank shown in FIG. 3, and a drying tank 200 (called a tumbler) shown in FIG. There is. In the cleaning/deliquid tank 100, the same steps as (1), (2), and (2) above, which are the cleaning steps using other solvents described above, are carried out 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, remove the dehydrated clothing 2 from the door 1, and
It is poured into the processing tank 10a through the door 1a of the tumbler shown in the figure.

In the tumbler, outside air 20a is taken in through an inlet duct 19a by a fan 16, heated by an 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.
Drying is completed.

Although general dry cleaning processes using various solvents have been outlined above, dry cleaners that use these solvents currently employ a cleaning and drying method using a single solvent.

Table 1 compares the typical physical properties of currently widely used solvents. Furthermore, Table 2 compares the dry cleaning characteristics, restrictions, drawbacks, etc. caused by typical physical properties of the solvents shown in Table 1.

In order to respond to the recent diversification of clothing materials, processing, and forms, we have added, for example, two types of dry cleaners: perchlorethylene dry cleaner and Freon 113 dry cleaner, and furthermore, 1,1.1 trichloroethane dry cleaner. This required three types of dry cleaners, which placed an extremely heavy burden on cleaning companies, as it required increased purchasing funds, space, equipment capacity, etc., and complicated maintenance work.

Table 1 Table 2 In order to solve these problems, the present inventors previously proposed in JP-A-61-154698 that they used the solvents listed in Table 1 that are currently commercially available as dry cleaning solvents. On the premise that at least two types of mutually soluble solvents can be stored separately, tanks are provided, and each solvent can be supplied to the processing tank.
Furthermore, it has the ability to purify each solvent alone or a mixture of each solvent, and uses one dry cleaner to use different solvents depending on the type of clothing, or to obtain intermediate physical properties of each solvent. For this purpose, we proposed a method of cleaning by mixing two or more types of solvents in arbitrary proportions.

(Problem to be solved by the invention) By the way, dry cleaners using these solvents are
Both types of solvents pose pollution problems, both large and small. Among them, CFC-113, which is said to be the least toxic and has been rapidly increasing in recent years, has very stable properties, so the gas that escapes into the atmosphere does not decompose easily, and ultimately ends up on the earth. Gradual production restrictions on an international scale are to be implemented starting in 1988, as the ozone layer that surrounds the world is destroyed.

In addition, the issue of groundwater contamination with perchlorethylene and 1,1.1-1-lichloroethane, and the problem of air pollution with turpentine are becoming more serious. The surrounding environment is becoming increasingly harsh.

The present invention has been made based on these circumstances,
We found a low-pollution solvent to replace the above solvent, and at the same time
The purpose is to provide a dry cleaning method that can be used for a variety of clothing materials using a stand-alone dry cleaner.

(Means and effects for solving the problem) That is, the present invention includes a processing tank that stores clothing, a plurality of storage tanks that store mutually soluble solvents individually or as a mixed solution,
A first dry cleaning apparatus is used, which has a solvent supply selection device that selects the solvent to be supplied from the same tank to the processing tank, and a solvent recovery device that leads the used solvent from the processing tank and returns it to the respective storage tank. 1,1-dichloro-2,2,2-trifluoroethane as a solvent, a perfluorocarbon known as an inert liquid as a second solvent, and tetrachlorodifluoroethane as a third solvent in arbitrary proportions. Mix and wash as a composition.

This is a means of solving the above problems.

Before the above structure was established, the present inventors first studied the basic characteristics of a laundry cleaning agent in order to select a new laundry cleaning solvent that would less likely destroy the ozone layer. The scope of the investigation was expanded to include organic solvents that are produced as cleaning agents for clothing, but which had not previously been considered as detergents for clothing. As a result, Freon 123 (1,1-dichloro-2,2°2
-trifluoroethane) and perfluorocarbons (for example, perfluoroalkanes, etc.) in an arbitrary ratio.

Although the purpose of pollution prevention can be achieved by employing this, perfluorocarbons are expensive and it is not economical to use them in large quantities. Also,
Since perfluorocarbons are inert, it is extremely difficult to disperse detergents and finishing agents essential for washing clothes into a solvent solution, and it has been found that most detergents cannot be used. In this case, the items to be washed are limited to certain types of clothing that do not require detergent or finishing agents.

Therefore, in the present invention, Freon 1, which has been confirmed to be easily decomposed in the atmosphere and has high cleaning power, is used.
23 (1,1-dichloro-2,2,2-trifluoroethane) and Perfluorocarbon (1,1-dichloro-2,2,2-trifluoroethane), which is known as an inert heating medium and has low toxicity and does not cause ozone layer depletion, is used as a cleaning power modifier for Freon 123. As a result of further research on the premise of adopting perfluoroalkanes, perfluorocycloalkanes, perfluoroaromatics, etc., we found that the price of perfluorocarbons has been adjusted and that fluorocarbons are being used as dissolving and dispersing agents for detergents and finishing agents. 112 (tetrachlorodifluoroethane) was found to be suitable.

Therefore, the present invention employs a mixture of these champions as a laundry detergent, and thereby attempts to significantly reduce the problems of ozone layer depletion and groundwater contamination caused by perchlorethylene, which are problems associated with conventional fluorocarbon solvents. It is something.

Note that the ozone depletion power of Freon 123 is said to be 0.05 or less, that is, 1720 or less, when Freon 11 is taken as 1.

(Example) Embodiments of the present invention will be described below based on the drawings.

A typical embodiment of the present invention is shown in FIGS. 1 and 2. FIG. First, the basic embodiment of the present invention will be explained with reference to FIG. 1. The first difference between this figure and FIG. 3 showing the conventional method is that the first solvent storage tank The second solvent storage tanks 3a are provided independently from each other, and each is provided with a dedicated valve 5, 5a.

The second point is the water separator 2, which can be used depending on the specific boiling point of the solvent or by program control.
2.22a, valves 32.32a, solvent pipes 23, 23a, and water pipes 2 are installed in the condensed solvent inflow pipe 34, respectively.
9.29a is attached, and a safety valve 33 is additionally installed on the capacitor 27.

The third point is that the recovery path 21 connected to the air cooler 17 is connected to the water separator 22 through the valve 30 or 30a.
or 22a, and connected to the distiller 15 via the check valve 31.

The main differences from the conventional one are the above three points, and the other components are almost the same as in FIG. 3. Although it is of course conceivable to dedicate the pump 6 for each type of solvent, here it is shared in order to use an hour wheel.

FIG. 2 shows an example of the configuration of a condenser that allows more complete fractional recovery of two types of solvents. The riser pipe 36 of the distiller 15 (FIG. 1) is connected to a first condenser 27a, and the condenser 27a has two solvents at boiling points.
A cooling coil 41 is installed, which is adjusted to a temperature equal to or 2 to 3° C. higher than the lower value by a control system (not shown). Further, the lower part of the condenser 27a is branched into a gas pipe 37 and a liquid pipe 38, and the liquid pipe 38 is immersed in a tank 35 filled with cooling water 40a in a low-temperature cooling coil 40, and then passed through a water separator. 22a (FIG. 1).

Further, the gas pipe 37 is connected to a second condenser 27b, and the condenser 27b is equipped with a low-temperature cooling coil 40 cooled to a temperature that can sufficiently condense a low-boiling point solvent. Furthermore, the liquid pipe 39 at the bottom of the condenser 27b is connected to the water separator 22a (FIG. 1).

Next, in the dry cleaner configured as above,
Regarding the effect when a mixture of perfluorohexane and Freon 112 is used as the first high boiling point solvent 4, and Freon 123 is used as the second low boiling point solvent 4a, and both are mixed and used in an arbitrary ratio. explain in detail.

(2) A required amount of the first solvent 4 is pumped up from the tank 3 via the valve 5 and the pump 6 via the valve 7, the filter 8, or the valve 9 into the processing tank 10. Subsequently, the second solvent 4a is similarly pumped up from the tank 3a via the valve 5a.

■, Slowly rotate the processing drum 11 and use the mixed solvent (4+4
a) processing tank 10, button trap 12, valve 13,
Clothes 2 are washed by circulation through a circuit consisting of pump 6, valve 7, filter 8 or valve 9.

■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 mixed solvent (4+4a) in the clothing 2. Separate and drain as well.

■, Repeat the above steps ■, ■, and 0. Or, after repeating steps ① and ② above, transfer the treatment tank 11, button trap 12, valve 13, and pump 6 to the third tank (not shown).
The liquid is drained via piping (not shown).

■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 and collected in the recovery path 21.
and flows into the distiller 15 via the check valve 31.

■When the drying is finished, the dampers 25 and 26 will move as shown by the broken lines (
It is opened, fresh air is taken in from the damper 25, and uncondensed solvent gas that cannot be recovered by the air cooler 17 is exhausted from the damper 26, thereby deodorizing the solvent odor in the clothing 2.

The mixed solvent (4+4a) that entered the distiller 15 in the steps of ■, above ■, ■, and 0 is first distilled at the boiling point determined by the low boiling point solvent (solvent 4a in the example), and then distilled via the condenser 27. controlled by a temperature sensor (not shown);
It flows into the water separator 22a through the opened valve 32a, and returns to the tank 3a through the solvent pipe 23a.

Next, as the low boiling point solvent 4a in the distiller 15 decreases, the boiling point gradually approaches the boiling point of the high boiling point solvent 4, and the distillation of the high boiling point solvent 4 starts, but as described above. The distillation temperature sensor (not shown) is activated to open the valve 32 (the valve 32a is closed), and the high boiling point solvent 4 is recovered into the tank 3 in the same manner as described above (the high boiling point solvent is higher than the low boiling point solvent). The intermediate component solvent when switching to a solvent is actually a very small amount and poses no practical problem, so it is treated as any solvent.

).

Here, to briefly explain the fractional distillation method shown in FIG. 2, the low boiling point solvent 4a evaporated from the distiller 15 (FIG. 1)
first enters the first condenser 27a, but the cooling coil 4
Since the cooling water temperature of No. 1 is higher than the boiling point of the low boiling point solvent 4a, it does not condense, enters the second condenser 27b through the gas pipe 37, is condensed by the low temperature cooling coil 40, and passes through the liquid pipe 39 to the water separator. 22a. Next, when the high boiling point solvent 4 begins to evaporate, it can be recovered in the first condenser 27a and flows into the water separator 22 through the liquid pipe 38. The tank 35 filled with the cooling water 40a of the low-temperature cooling coil 40 has the function of cooling the liquid pipe 38 immersed in the cooling water 40a.

In the embodiment shown in FIGS. 1 and 2, in order to simplify the expression, perfluorocarbon and Freon 112 are mixed at a fixed ratio as the first solvent 4a and stored in the dedicated solvent tank 3a, and the second solvent is Freon 123 as the solvent 4 is stored separately in the dedicated solvent tank 3, and two types of solvents 4, 4
Although a configuration example corresponding to a is shown, it goes without saying that each solvent can be handled individually and three types of solvents can be handled in the same manner.

Thus, in the present invention, Freon 123, which is highly decomposable in the atmosphere, is used as a cleaning solvent, and perfluorocarbons (for example, perfluoroalkanes, perfluorocycloalkanes, perfluorobenzenes, etc.) are used as a cleaning power modifier. These are known as inert liquids, and do not show any dissolving power for most oils, resins, and considerable organic solvents, and only slightly dissolve fluorocarbon-based cutting at a given rate. . Therefore, in the present invention, in addition to the above two types of solvents, Freon 112, which has low cleaning power as a detergent essential for dry cleaning and a dissolving agent for finishing agents, is used in combination with each of the above solvents. The combination is unique.

That is, as already mentioned, in the present invention, low-pollution fluorocarbon 123 is selected as a cleaning agent, and this cleaning power is achieved by mixing fluorocarbon 112, which is also a low-pollution perfluorocarbon, and fluorocarbon 112 as a dissolving agent for detergents and finishing agents. It is unique in that it can be adjusted depending on the situation.

The present inventors conducted a detergent dissolution test on solutions by changing the mixing ratio of the three solvents mentioned above. As a result, the mixed solution of Freon 123 and perfluorohexane could hardly dissolve detergent; It was found that detergent can be easily dissolved by adding . The results are shown in Table 3.

We have found that it can be equivalent to the third table force (particularly paying attention to the influence on delicate clothing).

Table 4 In addition, when we conducted a cleaning performance evaluation test with different mixing ratios of the three solvents, as shown in Table 4, when the mixing ratios were appropriately selected, the cleaning performance was as high as that of conventional Freon 113 and perchlorethylene, respectively. Cleaning Also, Table 5 shows the change in cleaning rate of carbon-contaminated cloth (Japanese, Kitomari Chemical Society standard contaminated cloth) when the mixing ratio of Freon 123, perfluorohexane, and Freon 112 was changed to 1p, the same as in Table 4. The figure shows the pigment Jlt [1X (magnified 40 times and the total area of falling off with an image processing device n) of the printed fabric (product name: imitation sequins) on which the pigment is fixed with acrylic resin glue, but the same It can be seen from the table that by adjusting the mixing ratio of solvents, the cleaning characteristics and the dissolution characteristics of resin, etc. can be adjusted as desired.

Table 5 The cleaning rate mentioned here is calculated by the following formula.

Wa - Wl Wo: whiteness of carbon-contaminated cloth before contamination W1: whiteness of carbon-contaminated cloth before cleaning w8: whiteness of carbon-contaminated cloth after cleaning Although it has been explained above, the same effect can be obtained using other substances such as perfluorocyclohexane which is a perfluorocycloalkane, or perfluorobenzene which is a benzene type.

(Effects of the Invention) As described above in detail, according to the present invention, one dry cleaner can use three solvents, Freon 123, perfluorocarbon, and Freon 112, in any mixing ratio, and can be used for most clothing materials. It is now possible to wash clothes using the most suitable washing method for the processing and shape, reducing the number of washing-related accidents (inappropriate washing,
Wrinkling, shrinkage, decarburized color, stiffness, adhesive material falling off, etc.) can be significantly reduced, and it also eliminates social problems on a global scale, such as when using conventional solvents, such as Freon 113. This can significantly reduce ozone layer depletion and groundwater pollution caused by the use of perchlorethylene solvents.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a typical dry cleaner for implementing the present invention, Fig. 2 is a circuit diagram of the fractional distillation method in the same dry cleaner, Fig. 3 is a system diagram of a conventional dry cleaner, and Fig. 4 and FIG. 5 is a system diagram for explaining a conventional dry cleaning process using a turpentine. Description of main parts of the figure 2 - Clothing 3.3a - Storage tank for solvents 4.4
a... Solvent 5, 5a-- Dedicated valve 22.
22a...-Water separator 23,23a--Solvent piping 2
7...Condenser 29.29a--Water piping 32.
32a・-Pulp 1st circle 2nd figure Patent Applicant: Mitsubishi Heavy Industries, Ltd. ÷ 40, ni＼-ノ

Claims (1)

[Claims] A processing tank that stores clothing; a plurality of storage tanks that store mutually soluble solvents individually or as a mixed solution;
A first dry cleaning apparatus is used, which has a solvent supply selection device that selects the solvent to be supplied from the same tank to the processing tank, and a solvent recovery device that leads the used solvent from the processing tank and returns it to the respective storage tank. 1,1-dichloro-2,2,2-trifluoroethane as a solvent, a perfluorocarbon known as an inert liquid as a second solvent, and tetrachlorodifluoroethane as a third solvent in arbitrary proportions. A dry cleaning method characterized by mixing and cleaning.