JPH0586240B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vacuum distillation method for dry cleaning using a solvent such as tetrachloroethylene (commercially traded perchlorethylene).

[Conventional technology]

FIG. 3 shows a conventional dry cleaning apparatus, and each process of conventional dry cleaning by atmospheric distillation will be explained based on this figure.

First, open the door of basket A, put the items to be washed into the basket, and start operation.

First, the pre-washing process begins.

That is, tetrachlorethylene (hereinafter referred to as solvent) is transferred from base tank 1 or 2 to valve S ₁ or S ₂
and _S4 , the required amount is pumped by pump P into basket A via pumping valve _S5 . Further, at the same time as the operation starts, the basket A is rotated forward and backward at low speed to mechanically remove dirt from the items to be washed. Dirt can be dissolved by the mechanical impact described above or by solvents, soaps, etc. When the required amount of solvent reaches the basket, pump P is temporarily stopped, and then the solvent is transferred from basket A to button trap 3 to valve S _10.
→ Pump P → Valve S ₅ → Circulate to basket A, and the button trap 3 collects the buttons, lint, etc. that have come loose from the items to be washed, and the shower cleaning process is performed.

After the above-mentioned shower cleaning process, the liquid removal process begins.

That is, after the shower cleaning process is completed, the solvent is drained into the distiller 4 via basket A→button trap 3→valve _S10 →pump P→valve _S6 . The liquid may be drained from basket A at low speed or at high speed.

The dirty solvent in distiller 4 is indirectly heated with a steam heat source of 4 to 5 kg/ ^cm2 , and the inside of the distiller is at normal pressure (atmospheric pressure 0).
Kg/cm ² gauge) and boils at 121℃. distiller 4
The solvent vapor evaporated in the tank enters the condenser 6 via the standpipe 5, where it is liquefied and sent to the water separator 7.
A deliquification process is performed in which the solvent and water are separated by specific gravity and the solvent is recovered into the base tank 18. Also, at this time, water is discharged outside the machine.

Next, the items to be washed in basket A enter a circulation washing process through a filter.

That is, the solvent is transferred from the base tank 18 to the valve S ₃ ,
The required amount is sent to pump P → valve S ₅ → basket A via S ₄ . When the required amount of solvent is reached, the pump P is temporarily stopped in the same way as in the washing process, and the solvent is passed through the basket A → button trap 3 → valve S ₁₀ → pump P → valve S ₇ , and the centrifugal filter 8 captures the dirt particles. The filter is circulated and cleaned by returning to the basket A via the collection valve _S7 '. At this time, soap is introduced via the hopper 14 and valve _S8 . After the filter circulation cleaning process is completed, the liquid removal process begins.

In this process, the solvent is pumped into basket A → button trap 3 → valve S ₁₀ → pump P → valve S ₉ and valve S ₁ or
The liquid is drained to the base tank 1 or 2 via _S2 . Drain the liquid by changing basket A from low speed to high speed.

Once the above washing process is completed, the next drying process begins.

In the drying process, a fan 10 in the air duct 9,
Drying is carried out in a hot air circulation system using an air cooler 11, an air heater 12, and a lint filter 13, and the solvent vapor liquefied in the air cooler 11 is guided to the water separator 7 through a pipe 15 as in the distillation operation.

After that, the deodorization process begins.

That is, in the above-mentioned washing process, since the items to be washed in the basket A contain solvent saturated vapor at the drying temperature, the fan 10 is driven and the valves S ₁₁ ,
By opening _S11 ', fresh steam is introduced into basket A from outside the machine, and residual solvent vapor in the items to be washed is discharged outside the machine.

[Problem that the invention seeks to solve]

In the case of the conventional method described above, the dehydration process after shower cleaning requires a distiller, condenser, water separator,
Since distillation is carried out at normal pressure in the base tank, etc., the distillation time is longer, the heat source steam needs to be at high pressure, and a large amount of cooling water must be passed through the condenser, which may cause bumping during distillation. There were some problems.

[Means for solving problems]

In order to solve the above problems, this invention shortens the distillation time by reducing the pressure in the stand pipe, condenser, and water separator using a vacuum pump during the deliquoring process after shower cleaning in dry cleaning. .

[Effect]

Since this invention is as described above, in the dry cleaning process, when the liquid removal process after shower cleaning is started, the lower part of the condenser is connected to the vacuum pump, and the vacuum pump is started to connect the distiller, standpipe, and condenser. By reducing the pressure inside each device of the water separator, deliquid treatment is performed in a reduced pressure state.

〔Example〕

FIG. 1 shows a dry cleaning apparatus employing the vacuum distillation method of the present invention.

Since the deodorizing steps explained in detail in FIG. 3 are the same in this invention, only the different points will be explained below.

In the case of this invention, at the same time as the solvent in the basket A starts draining into the distiller 4 in the deliquid process after shower cleaning, the valve S ₁₃ . S ₁₇ opens and vacuum pump 16 connects distiller 4, condenser 6, water separator 7,
The base tank 18 is evacuated and becomes depressurized. During the process, when the inside of the exhaust system reaches a predetermined degree of vacuum, the vacuum pump 16 is stopped and the valve _S13 is closed. However, the longest driving time of the pump 16 is until the end of the process.

The timing of opening and closing of each valve S ₁₃ to _{S 20} is shown in the time chart of FIG. 2. Moreover, each of the above-mentioned valves S ₁ to _{S 20} are all automatic valves.

〔effect〕

In this invention, as mentioned above, in the dehydration process after shower cleaning, the distiller, condenser, water separator, and base tank are brought to a reduced pressure state using a vacuum pump, so the distillation time is reduced to 1/3 of the conventional normal pressure method. In the conventional method, the heat source steam was 4 to 4.5 Kg/ ^cm2 ,
In the case of this invention, a low pressure of 1.5 to 20 kg/cm ² is sufficient;
Distillation can be performed at a low temperature of 85℃ or less (previously 121℃)
Therefore, there is no bumping during distillation, and the amount of cooling water for the condenser can be reduced, resulting in water savings.

[Brief explanation of the drawing]

FIG. 1 is a piping system diagram of an apparatus for carrying out the method of the present invention, FIG. 2 is a time chart showing the opening and closing of each valve, and FIG. 3 is a piping system diagram for an apparatus for carrying out the conventional method. 1, 2, 18... Base tank, 3... Button trap, 4... Distiller, 5... Stand pipe, 6... Condenser, 7... Water separator, 8...
Centrifugal filter, A...basket.

Claims (1)

[Claims] 1. A pre-washing process in which solvent is supplied from a base tank into a basket that accommodates the items to be washed and is repeatedly rotated forward and reverse; a shower cleaning process in which the solvent discharged from the basket is returned to the basket via a button trap after the pre-washing process; and a shower cleaning process in which the solvent is returned to the basket via a button trap After the cleaning process is completed,
The solvent that has passed through the button trap from the basket flows into the distiller as waste liquid, where the waste liquid is indirectly heated by a steam heat source, and the evaporated solvent vapor is introduced into the condenser and water separator via the stand pipe, where water is removed. There is a deliquification process in which the separated solvent is returned to the base tank, a circulation cleaning process in which the solvent collected in the base tank is sent to a basket that rotates forward and backward, and the solvent that has passed through the basket is returned to the basket via a button lamp and filter. There is a deliquification process in which the solvent after the cleaning process is returned to the base tank via the basket or button trap, a drying process in which hot air is circulated inside the basket after deliquification, and a residual solvent vapor in the basket etc. after the drying process is removed from the machine. In dry cleaning, which consists of a deodorizing process in which deodorizing air is released and replaced with fresh air, the distillation time is shortened by reducing the pressure in the stand pipe, condenser, and water separator using a vacuum pump in the dehydration process after the shower cleaning process. A vacuum distillation method for dry cleaning, characterized by: