JP2971127B2 - Dry cleaning method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a dry cleaner in which a solvent gas by dry cleaning is prevented from being discharged outside the apparatus.

(Prior Art) A conventional dry cleaning apparatus is configured as shown in FIG. 3, and a cleaning step includes a cleaning step, a liquid removing step, a drying step, and a deodorizing step.

First, in the washing step, the article 1 to be washed is perchlorethylene,
1.1.1-Soak in highly volatile solvents such as trichloroethane, R11 and R113 to remove dirt. Further, in the liquid removing step, the washing drum 02 is rotated at a high speed to centrifuge the solvent. In the drying process, the air in the cleaning device is circulated by a fan 03.
Thereby, the water is passed through the water-cooled cooler 04 and the heater 05 and circulated into the washing drum 02.

That is, the temperature of the air is raised by the heater 05 to evaporate the solvent adhering to the article 01 to be washed, and the evaporated solvent gas is guided to the water-cooled cooler 04 to be cooled to about 32 to 35 ° C. Thus, the solvent gas is condensed and liquefied and recovered. However, the solvent gas contained in the air is better removed as the cooling temperature is lower due to the saturation concentration. Therefore, for example, when the solvent is perchlorethylene, the concentration of the solvent contained in the air is reduced at a cooling temperature of about 35 ° C.
It cannot be reduced to 250 g / m ³ or less.
Strong odor remains in 1. Therefore, in the deodorizing step, the fresh air damper 06 is opened to take in the outside air to remove the odor and cool the object 01, and the outside air is brought into contact with the object 01 to dilute the solvent gas concentration, and the exhaust gas is exhausted. It is discharged out of the machine from the damper 07.

Although this exhaust gas was diluted, it was initially tens of thousands of ppm.
Solvent gas is discharged through the duct 08 through a duct 08 for the purpose of countermeasures and resource saving by solvent recovery. The activated carbon tank 010 adsorbs only clean air to the atmosphere. When the activated carbon reaches saturation with the adsorbed solvent gas, the solvent adsorption tank 09 sprays water vapor on the activated carbon from the steam pipe 01 to evaporate the solvent and perform so-called desorption. The evaporated solvent gas is led to the water-cooled condenser 012 to be condensed and liquefied, and is separated and recovered by the water separator 013 into a recovered solvent and water. After the desorption step, the drying fan 014 is operated to start a drying step of drying the activated carbon tank 010, and the activated carbon tank 010 is regenerated to prepare for the next adsorption step.

(Problems to be Solved by the Invention) In recent years, social needs for pollution problems have increased, and the regulations have been increasingly strengthened. Exhaust gas regulations for perchlor ethylene are 50 ppm or less (Kanagawa Prefecture). On the other hand, the solvent content in wastewater is the world's strictest regulation of 0.1 ppm or less according to the Water Pollution Control Law.

On the other hand, in the conventional steam desorption type solvent recovery device, the gas exhausted via the activated carbon can be reduced to 50 ppm or less at the time of desorption at the time of deodorization of the dry cleaner. That is, it is difficult to take measures against the initial breakthrough. In addition, the steam used for steam desorption becomes wastewater, and since about 200 ppm of perchlorethylene is present in the wastewater, it is necessary to purify the wastewater. This is the amount of waste water generated in dry cleaning is 20cc
The wastewater from steam desorption is about four times as large as that of clothing / kg of clothing, and the cost is high.

The present invention seeks to solve the above-mentioned conventional problems,
The aim is to provide a dry cleaner that eliminates exhaust air and reduces the amount of wastewater.

(Means for Solving the Problems) For this reason, the present invention combines a dry cleaner having a circulation fan, a cooler, a heater, a processing drum and the like, and a pressure fluctuation adsorption type adsorption device having an adsorption device, a vacuum pump and the like,
The exhaust outlet of the dry cleaner and the solvent gas suction side of the adsorber are connected by a duct, and the fresh air inlet of the dry cleaner and the gas discharge side of the adsorber are connected by a duct to perform cleaning, drying, deodorization, etc. In the dry cleaner, when deodorizing the dry cleaner, the pressurized gas can be circulated to the processing drum via the adsorber, and when desorbing, the pressure is reduced by the vacuum pump connected to the gas suction side of the adsorber. The solvent gas by dry cleaning is prevented from coming out of the apparatus by conducting the desorption to the condenser located downstream of the apparatus, and this is used as a means for solving the problem.

(Function) A solvent recovery device having an adsorption tank for activated carbon etc. is installed to adsorb and collect the solvent gas generated in the deodorization step, which is the final step of dry cleaning, while using the low concentration gas passed through the adsorption tank as deodorizing gas for clothing. use. In addition, water vapor is not used at the time of desorption of the adsorption and recovery device for activated carbon or the like, and the solvent is desorbed from the adsorption tank by depressurizing using a vacuum pump and desorbed, and then condensed and liquefied by a condenser and collected. That is, the drainage tank is eliminated by desorption by the pressure swing method.

In the present invention, by combining the adsorption device based on the pressure fluctuation type adsorption method with the dry cleaner, the exhaust gas at the time of deodorization is returned to the treatment tank via the adsorption tank, so that there is no exhaust gas. In addition, since water vapor is not used for desorption, the generation of water due to the recovery is only a slight amount of water evaporated from the clothing. Therefore, it is not necessary to increase the cost for drainage purification. Further, since heat desorption with steam is not performed, one of the effects is that the recovered solvent is less deteriorated.

(Embodiments) The present invention will be described below with reference to the embodiments in the drawings.
The figure shows an embodiment of the present invention. In the drying process of the dry cleaner, a processing tank with a built-in washing drum 1 and a circulation fan
2, the gas is circulated through the water-cooled cooler 3, the switching damper 5, the air heater 4, and the fresh air inlet 19 for drying.

In the next deodorization step, the gas flow is passed through the treatment tank 1, the circulation fan 2, the water-cooled cooler 3, the switching damper 5, the duct 20, and the valve 14, and the gas pressurized is led to the adsorption tank 7, It is adsorbed by an adsorption tank (not shown) in the adsorption tank. This adsorbent may be an adsorbent used in a pressure fluctuation type adsorption method (pressure, swing, adsorption method) in which the pressure is reduced and desorbed during desorption, and preferably, zeolite, silica, activated carbon, or the like is used. The gas whose concentration has been reduced by this adsorption reaches the fresh air inlet 19 through the valve 13 and the duct 21 and returns to the processing tank 1. This flow is circulated for a predetermined time. At this time, valves 12, 15, 16
Is closed.

On the other hand, the adsorption tank 6 is used to desorb the adsorbed solvent.
The valve 17 is opened, and the pressure is reduced by the vacuum pump 10. The adsorbed solvent evaporates due to this reduced pressure, and the gas is discharged to the condenser 11
Sent to In addition, in order to facilitate this barrel wearing, the adsorption tank 6
Is provided with a heating device 8. The heating device 8 does not heat during adsorption, but heats during desorption, and the same applies to the heating device 9. The solvent sent to the condenser 11 as described above is condensed in the condenser 11 and liquefied and recovered. The liquefied solvent is led to a solvent tank (not shown) of the dry cleaner via the pipe 18 and reused. The whole dry cleaning process takes 20 to 30 minutes, and the deodorization takes 2 to 3 minutes.

As shown in FIG. 1, when two adsorption tanks are used, desorption can be performed for the entire process time. However, when one adsorption tank is used, the steps other than the deodorization step can be desorbed. The above-mentioned adsorption tank 7 is on the adsorption side, and the adsorption tank 6 is on the desorption side. However, the opposite will occur during the next dry cleaning, and since the adsorption tank 6 becomes on the adsorption side, the valves 16 and 12 are opened and the valves 14 and 13 are opened. , 17 are closed, and the adsorption tank 7 is on the desorption side. Here, when the valve 15 is opened and the vacuum pump 10 is turned on, it is desorbed from the adsorption tank 17. Second
The figure shows the dry cleaning process and the operation of each adsorption tank.

(Effects of the Invention) As described above in detail, the present invention can reduce the heating temperature and reduce the deterioration of the solvent because it is desorbed by reducing the pressure with a vacuum pump. Further, the exhaust gas at the time of deodorization is returned to the treatment tank via the adsorption device, so that there is no exhaust gas. In addition, since water vapor is not used for desorption, the generation of water due to recovery is only a small amount of water evaporated from clothing. Therefore, it is not necessary to increase the cost for drainage purification. One of the effects is that since the solvent is not desorbed by heating with steam, the recovered solvent is less deteriorated.

[Brief description of the drawings]

FIG. 1 is a system diagram of a dry cleaner according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a relationship between a dry cleaning process and a process of an adsorption tank, and FIG. 3 is a system diagram of a conventional dry cleaner. Description of main parts in the drawing 1 ... treatment tank, 2 ... circulation fan 3 ... water-cooled cooler, 4 ... air heater 6, 7 ... adsorption tank, 8, 9 ... heating device 10 ... vacuum pump, 11 …… Condenser 5,12,13,14,15,16,17 …… Valve

Claims (1)

(57) [Claims] A combination of a dry cleaner having a circulation fan, a cooler, a heater, a processing drum, and the like, and a pressure fluctuation adsorption type adsorption device having an adsorption device, a vacuum pump, etc., and an exhaust outlet of the dry cleaner and a solvent of the adsorption device. The gas suction side is connected by a duct, and the fresh air inlet of the dry cleaner and the gas discharge side of the adsorption device are connected by a duct, respectively, to perform cleaning, drying, deodorization, etc. The pressurized gas can be circulated to the processing drum via the device, and at the time of desorption, the pressure is reduced by the vacuum pump connected to the gas suction side of the adsorption device, and the pressure is led to the condenser downstream of the vacuum pump for desorption and collection. A dry cleaning method, wherein the solvent gas by dry cleaning is prevented from being discharged outside the apparatus.