JPH0425119Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a solvent recovery device applied to dry cleaning machines and the like.

(Prior Art) First, a general dry cleaning process will be outlined using FIG.

When the clothing 2 is put in through the door 1, the door 1 is closed, and the operation is started, the steps generally proceed in the following order.

The solvent 4 is pumped up from the solvent tank 3 through the valve 5 by 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.

Gently rotate the processing drum 11 and pour the solvent 4 into the 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.

Processing tank 10, button trap 12, valve 1
3, the liquid is drained through the path of the pump 6, the valve 14, and the distiller 15, and then the processing drum 11 rotates at high speed to centrifugally separate the solvent 4 in the clothing 2, and the liquid is drained in the same way.

Repeat the steps in section and section.

Processing tank 10, button trap 12, valve 1
3. Drain the solvent 4 through the path of the valve 5, then rotate the processing drum 11 at high speed to centrifugally separate the solvent 4 in the clothing 2, and drain it in the same way.

The processing drum 11 is slowly rotated again, and air is circulated in the direction of the arrow 20 between the recovery air duct 19 consisting of the fan 16, the air cooler 17, and the air heater 18 and the processing tank 10, thereby drying 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 clean tank 24 through the solvent pipe 23.

When drying is completed, dampers 25 and 26 open as shown by broken lines, 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 solvent 4 that entered the distiller 15 in the step 2 evaporates and is condensed and recovered in the condenser 27, enters the clean tank 24 through the water separator 22 and solvent piping 23, and is transferred to the solvent tank 3 from the overflow partition plate 28. Return. Note that the water separated by the water separator 22 is discharged to the outside of the system through a water pipe 29.

Next, the solvent recovery device will be described. The solvent gas evaporated from the clothing 2 during the drying process is cooled by the air cooler 17 and condensed and recovered. air cooler 1
7 is usually water-cooled and uses well water to cool the solvent gas to about 32 to 35 degrees Celsius. Therefore, the solvent gas is condensed and liquefied and recovered, but the lower the cooling temperature, the better the solvent gas contained in the air is removed due to the saturation concentration. For this reason, for example, if the solvent is perchlorethylene, the concentration of the solvent in the air cannot be reduced to less than 250 g/m ³ if the cooling temperature is around 35°C, and if this continues, a strong odor will remain on the clothing 2. become. Therefore, in the deodorizing process, in order to remove odors, the damper 25 is opened to take in outside air, which is brought into contact with the clothing 2 to dilute the solvent gas concentration, and is then discharged from the damper 26 to the outside of the machine.
However, although the exhaust gas is diluted, it initially releases solvent gas that reaches tens of thousands of ppm, causing air pollution.

In order to counter this problem and to save resources through solvent recovery, conventionally, the solvent gas is passed from the damper 26 through the duct 30 to the solvent recovery device 31 shown in FIG. Only clean air is released into the atmosphere.
When the activated carbon reaches saturation with solvent gas, the solvent recovery device 31 blows high-pressure steam generated in a boiler (not shown) through a steam pipe 33 to evaporate the solvent. So-called detachment is performed. The evaporated solvent gas is led to a water-cooled condenser 34 where it is condensed and liquefied, and is separated into a recovered solvent and water by a water separator 35 and recovered. Following the desorption process, a drying process is generally performed in which the drying fan 36 is operated to dry the activated carbon layer 32, and the activated carbon layer 32 is regenerated in preparation for the next adsorption process.

By the way, in order for the activated carbon layer 32 to completely adsorb the solvent gas, a contact time of a certain length or more is required, and although it depends on the flow rate of the solvent gas, it is usually 300 to 300 seconds.
The layer thickness is usually 500mm. In the desorption process, high-pressure steam is sprayed from the top of the activated carbon layer 32 to heat it and evaporate the solvent, but as the layer is thick as described above, it takes a considerable amount of time to heat the bottom layer. The reality is that this is getting in the way.

(Problems to be solved by the invention) As described above, in the conventional recovery equipment for this type of solvent, the activated carbon layer must be made thick in order to completely adsorb the solvent gas in the air. In the desorption process, it takes a long time for the heating with high-pressure steam to reach the lower layer, which poses a major problem in terms of processing efficiency.

The present invention has been made to solve these problems, and aims to provide a solvent recovery device in which the adsorption of solvent gas is as complete as before, and the desorption time is greatly reduced. It is something.

(Means for solving the problem) Therefore, the present invention uses a thin activated carbon layer that is made by dividing an activated carbon layer with a thickness of 300 to 500 mm according to the number of stages, to divide the internal space into upstream and downstream sides. At least two or more stages of partitioned solvent treatment tanks are provided in series in the flow direction of the solvent gas via on-off valves, and
A liquefied solvent outlet is provided in parallel on the upstream side of each treatment tank, and a desorption steam inlet is provided on the downstream side in parallel, and this is used as a means to solve the problem.

(Function) A plurality of activated carbon layers having a thickness of one-half to one-several times are connected in series so that the flow of solvent gas passes through each layer during solvent adsorption, thereby completely adsorbing the solvent. In addition, during desorption, high-pressure steam is blown into each activated carbon tank, so that each layer is desorbed in parallel, so it is possible to
Enables desorption in one to several fractions of the time.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is an explanatory diagram showing the configuration of a solvent recovery device according to an embodiment of the present invention.

The difference from the conventional device shown in FIG. 3 is that the conventional one solvent recovery device 31 is divided into two to several (the illustrated example shows a case of four), and each solvent recovery tank 31a to 31d is are connected in series via valves 41a to 41c, and each is provided with an activated carbon layer 32, 32, . Each of them is provided with a pressure steam supply port, and a steam discharge port is provided below the pressure steam supply port, and each of them communicates with one water-cooled condenser 34 via piping. The solvent gas discharged during the deodorizing process is passed from the duct 30 to the valve 3.
9 enters the lowest stage solvent recovery tank 31a, the solvent gas is adsorbed on the first stage activated carbon layer 32, and then passes through the valve 41a to the next stage solvent recovery tank 31.
In the same way, the solvent gas is adsorbed on the activated carbon layer 32 in the second stage, and in this way, it passes through the solvent recovery tanks 31c and 31d in the subsequent stages, gradually becomes clean air, and is released into the atmosphere from the valve 40. Ru. The adsorption function of activated carbon is determined by the layer thickness, and even if the layer thickness of each stage is thin, the same adsorption performance can be obtained if the total layer thickness is the same as that of the conventional device.

Since the activated carbon reaches saturation from the lower stage, when the uppermost stage reaches saturation, high pressure steam is blown from the steam pipe 33 onto each activated carbon one after another to evaporate the solvent, so-called desorption. The evaporated solvent gas passes through each pipe to a water-cooled condenser 34.
The solvent is condensed and liquefied as in the conventional method, separated into solvent and water in a water separator, and recovered.

In this embodiment as well, following the desorption step, a drying step is started in which the drying fan 36 is operated to dry the activated carbon layer 32 of each solvent recovery tank via the valve 38.
The same method as the conventional method is used to regenerate the activated carbon layer 32 and prepare it for the next adsorption step.

In addition, since the required amount of high-pressure steam to be blown onto each activated carbon layer 32, 32, etc. generally increases the lower the layer is, it is an energy-saving measure to adjust the flow rate of high-pressure steam to the activated carbon to the optimum value for each layer. This is an effective means.

(Effects of the invention) As explained in detail above, the present invention provides at least two or more stages of solvent treatment tanks containing a thin activated carbon layer in series in the flow direction of the solvent gas via on-off valves, and A liquefied solvent outlet is provided on the upstream side.
Desorption steam inlets are provided in parallel on the downstream side.

In general, solvent recovery equipment adsorbs solvent gas onto an activated carbon layer for the purpose of pollution prevention and resource conservation, and releases only clean air into the atmosphere.It requires a certain contact time and is dependent on the flow rate of the solvent gas. It depends, but
The layer thickness is usually 300 to 500 mm. On the other hand, in the desorption process, high-pressure steam is sprayed from the top of the adsorption tank to heat it and evaporate the solvent, but in the conventional case, the layer is thick, so it takes a considerable amount of time to heat up to the bottom layer, which shortens the time. It was getting in the way.

The present invention solves this conventional problem by using multiple activated carbon layers that are one-half to a few times thinner than conventional ones. The activated carbon layers are connected in series to completely adsorb the solvent, and during desorption, high-pressure steam is blown into each adsorption tank, so that each activated carbon layer is desorbed in parallel. This has the effect of making desorption possible in a fraction of the desorption time and providing an efficient solvent recovery device.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram of a solvent recovery device showing an embodiment of the present invention, Fig. 2 is a side sectional view showing the schematic configuration of a conventional dry cleaner, and Fig. 3 is a schematic explanatory diagram of a conventional solvent recovery device. be. Explanation of the main parts of the figure, 31...Solvent recovery device,
31a to 31d...Solvent recovery tank, 32...Activated carbon layer, 34...Condenser, 35...Water separator, 3
6...Drying fan.

Claims (1)

[Scope of utility model registration request] A thin activated carbon layer with a thickness of 300 to 500 mm is divided according to the number of stages, and the internal space is divided into an upstream side and a downstream side. At least 2 in the flow direction
What is claimed is: 1. A solvent recovery device characterized in that more than one stage is provided in series, and a liquefied solvent outlet is provided in parallel on the upstream side of each treatment tank, and a desorption vapor inlet is provided on the downstream side in parallel.