JPH027995A - Method for draining solvent to distiller - Google Patents

Abstract

PURPOSE:To reduce abrupt rise of pressure in a distiller tank in draining solvent by previously pouring a portion of cleaning solvent into the distiller several times prior to the draining when the used solvent is drained to the distiller. CONSTITUTION:In dry cleaning using organic solvent (for example, perchloroethylene and CFC-R113) for fractional distillation and recovery of used solvent through a distiller 15 in a process tank 10, a portion of cleaning solvent in the process tank 10 is previously poured into the distiller 15 several times prior to the draining of used solvent to the distiller 15. Air remaining in the distiller is expelled separately. To be brief, temperature of a heater portion of the distiller 15 is reduced to reduce the abrupt rise of pressure in the distiller tank in draining solvent. Thus, the life of strength of the distiller tank is elongated remarkably while abnormal sounds due to the strain of plate portions can be avoided, the apparatus may be built light in weight and in simple construction.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is a fluorine-based dry cleaner that uses a low boiling point solvent such as Freon R113 or Freon R11, or a combination of perchlorethylene and Freon R113 in one machine. The present invention relates to a method for draining a solvent into a still installed in a dry cleaner that uses a plurality of solvents.

(Prior Art) FIG. 4 shows an example of a dry cleaner using two types of solvents, perchlorethylene and Freon R113.

First, its configuration will be explained.

(1) The solvent tank 3 that stores the fluorocarbon R113 solvent 4 containing around 5 vol % of perchlorethylene and the solvent tank 3a that stores the perchloroethylene solvent 4a that contains around 50 vol 1 % of fluorocarbon R113 are installed independently from each other. A dedicated pulp 5, 5a is provided for each solvent tank 3, 3a.

The mixed solvent may be prepared in advance, but in reality, if pure solvents are initially stored and operated, the mixing ratio will be stabilized at a constant mixing ratio by the fractional distillation operation described below.

(2) The distiller 15 has a built-in sensor 30 that detects changes in boiling point during distillation, and is linked to a valve 32.

When the distillation starts, the arbitrary mixed liquid drained into the distiller 15 starts to evaporate from the solvent containing Freon R113, which has a low boiling point, and is liquefied, cooled, and recovered in the path of the condenser 27 and the solvent cooler 31. It's coming. During this time, the boiling point gradually rises. For example, if the sensor 30 is set at 70°C and the valve 32 is opened until this set value is reached (at this time, the valve 32a is closed), it will be around 5vo1%. Freon R113 containing perchlorethylene is returned to the solvent tank 3 through the water separator 22 and the solvent pipe 23.

Thereafter, the valve 32 is closed until the distillation is completed. If the valve 32a is left open during this time, perchlorethylene containing Freon R113 is transferred to the water separator 22a and the solvent pipe 23a.
and is returned to the solvent tank 3a.

In order to ensure the target mixing ratio, a capacitor 27,
It is necessary to eliminate the solvent retention part from the recovery route consisting of the solvent cooler 31 and to make the route as short as possible.

(3) The filter is provided with a filter 8 for perchlorethylene and a filter 8a for Freon R113 independently of each other, and valves 7 and 7 for each are provided so that they do not mix during circulation of the solvent.
．． 7a is provided.

(4) The recovery duct 19 is arranged on the side surface of the processing tank 10, and the air cooler 17 and preheater 18 housed inside the recovery duct 19 are connected to the refrigerator 42, respectively.

When drying, slowly rotate the processing drum 11 and turn on the fan 16.
The air is circulated in the direction of arrow 20. The solvent gas evaporated from the clothing 2 passes through a lint filter 40 built into the button trap 12, and is condensed and liquefied by the air cooler 17. The air is then heated again by the preheater 18 using the exhaust heat of the refrigerator 42, and further heated by the auxiliary heater 41 to a predetermined temperature specified by the thermostat 43 to dry the clothes 2.

When drying is completed, the cooling temperature of the air cooler 17 can be lowered by turning off the heating source, and the solvent gas concentration can be reduced to the minimum, so there is no need to take in fresh air and deodorize as with previous devices. Become.

The airbag 50 is connected to the suction side of the fan 16 via piping, and stores a mixture of air and solvent gas that volatilizes and expands during cleaning, and prevents pressure rise inside the device and also prevents the solvent gas from rising. It is glued to prevent leakage.

Next, its effect will be explained.

■ If the clothing 2 is heavily soiled, the perchlorethylene solvent 4a is pumped up by the pump 6 through the valve 5a, and the route passes through the valve 7 and the perchlorethylene filter 8, or the perchlorethylene solvent 4a is pumped up through the valve 5a. The required amount is sent to the processing tank 10 via a route.

■ If the clothing 2 is delicate clothing, it is pumped up by the pump 6 through the valve 5, and the fluorocarbon R11 is pumped up through the valve 5.
The fluorocarbon R113 solvent 4 is sent into the pumping treatment tank 10 through the route passing through the filter 8a for 3 or the route through the valve 9.

■ When pumping is completed, the processing drum 11 rotates slowly, and the solvent 4 or 4a is pumped through the button trap 12 and the valve 1.
3. The clothes 2 are washed by circulating through the pump 6 and the treatment tank 10 through the valve 7, 7a, or 9.

(2) When the washing is completed, the solvent 4 or 4a is drained into the distiller 15 via the valve 14, and then the processing drum 11 is rotated at high speed to centrifugally separate the solvent in the clothing 2, and the solvent is drained in the same manner.

When the steps from item 0 to item 0 above are repeated, the solvent 4 or 4a remaining in the pump 6 or the route, or the solvent 4 or 4a remaining in the clothing 2 when the solvents are used before and after the process, mix with each other to some extent. However, by keeping the proportion to a minimum, the solvent properties of each other will not be inhibited.

■ Any mixed liquid drained into the distiller 15 is
The solvent is fractionated again to a fixed mixing ratio by the method described in section 2) and returned to each solvent tank 3 or 3a.

(2) When the cleaning process is completed, the clothing 2 is dried by the method described in item (4) above, and the entire cleaning process is completed.

Although the combination of two types of solvents has been described above, three or more types of solvents can be handled in the same manner.

(Problems to be Solved by the Invention) As mentioned above, the solvent used for cleaning must be regenerated through a distiller in order to separate and remove dirt components, especially dirt dissolved in the solvent such as oils and fats. I use it repeatedly. In addition, when using multiple solvents with different physical properties such as perchlorethylene and Freon R113 in one machine, it is necessary to keep the composition of each solvent constant at all times.
The solvents mixed during washing are always distilled and fractionated.

However, as shown in Figure 5, the vapor pressure of the solvent varies greatly depending on the type of solvent, especially Freon R113 and Freon R
The vapor pressure of a low boiling point solvent such as No. 11 is extremely high.

For this reason, in conventional distillers, in order to reduce the pressure of the heated steam in the distiller to about 1 to 1.5 kg/cd, or to prevent overheating after distillation is completed, a thermostat is placed inside the tank. Once the distillation has finished and the temperature has risen to a predetermined level, methods have been used to reduce the pressure increase when the liquid is drained to the distiller, such as by stopping the supply of steam, but none of these methods are effective. In the end, the current solution is to design the tank more strongly or expand the evaporative gas recovery path to disperse the pressure.

The present invention has been made in order to solve this problem, and its object is to reduce the sudden pressure rise in the distiller tank when the solvent is drained as described above.

(Means and Effects for Solving the Problems) Therefore, in dry cleaning, when used solvent is distilled and recovered by fractional distillation, a portion of the solvent being washed is collected prior to draining the solvent into the distiller. is injected into the distiller in advance in several batches, the air remaining inside is divided and expelled, and if necessary, the temperature of the heated part of the distiller is lowered to prevent the rapid increase in the temperature in the distiller tank that occurs when the liquid is drained. Prevent pressure build-up.

As a result, the strength life of the +11 distiller tank is significantly extended, abnormal noise due to distortion of the plate can be avoided, and the device can be made lighter and simpler.

(2) It evaporates at near atmospheric pressure, making it possible to purify the solvent by stable distillation.

(Example) Hereinafter, a typical example of the present invention will be described based on FIG. 1 while referring to FIG. 4.

FIG. 1 is a time chart showing the operating states of each valve and pump. In the cleaning process, in order to pump up the Freon R113 solvent 4 to a certain level in the processing tank 10, the valve 13 is closed and the valves 5 and 9 are opened to form a circuit, and then the pump 6 is turned.

The pumping continues until a level switch (not shown) installed in the button trap 12 is activated, after which the pulp 5 is closed and the valve 13 is opened, allowing the solvent to circulate through the circuit and wash the clothes 2 in the processing drum 11. Wash.

Meanwhile, during this time, the valve 14 of the pipe leading to the circuit and the distiller 15 can be opened several times (twice at 20 second intervals in the illustrated example) for a short period of time (in the illustrated example, 2 times at 20 second intervals). of the solvent is injected into the distiller 15 in advance.

The amount of liquid injected into this distiller 15 is about 1 to 21,
The amount of cleaning liquid is less than the total amount of cleaning liquid, and there is no adverse effect on the cleaning effect. Note that the amount of injection liquid and the number of injections can be set arbitrarily.

Next, in the draining step, valve 9 is closed, valve 14 is opened, and all the solvent is sent to distiller 15.

During this time, the processing drum 11 rotates at high speed, and the solvent in the clothing 2 is also centrifuged and drained in the same way.

(Effects of the Invention) The effects of the present invention will be explained below with reference to FIGS. 2 and 3.

In Figure 2, the heating water vapor pressure of the distiller is lowered at the front.
This is data on the pressure inside the distiller when draining the liquid using the conventional method, and the pressure rises rapidly when draining, reaching a maximum of 0.3 kg/cIi.
reach.

On the other hand, Figure 3 shows data on the pressure inside the distiller when liquid is drained according to the present invention under the same conditions as in Figure 2. Although the pressure increases to 0.1 kg/cnl each during partial injection during cleaning, , up to 0.2 kg/c at the stage where a large amount of liquid is drained.
It only rose to around d.

Therefore, according to the present invention, there is no need to design a strong distiller tank, and the apparatus can be simplified, so that a dry cleaner can be provided at a low price.

[Brief explanation of the drawing]

Fig. 1 is a time chart showing a typical embodiment of the present invention, Fig. 2 is a data diagram of the pressure inside the distiller during draining according to the conventional method, and Fig. 3 is a data diagram of the pressure inside the distiller according to the present invention. , Figure 4 shows perchlorethylene and Freon R11 in one machine.
3 is a block diagram of a dry cleaner using a plurality of solvents, and FIG. 5 is a vapor pressure diagram of various solvents used in the dry cleaner. Explanation of main parts of the diagram 3.3a - Solvent tank 4 - Freon R113 solvent 4a - Perchlorethylene solvent 5.5a - Dedicated valve 6 - Pump 1〇 - Processing tank 15 - Distiller 27- Capacitor

Claims (1)

[Claims] In dry cleaning that uses organic solvents and collects the used solvent through fractional distillation through a distillation device, how many times is a portion of the solvent being washed prior to draining the used solvent to the distillation device? A method for draining a solvent into a distiller, characterized by dividing the solvent into portions and injecting the solvent into the distiller in advance.