JPH0567318U - Solvent recovery device - Google Patents

Abstract

(57) [Abstract] [Objective] The fibrous activated carbon as an adsorbent in an organic solvent gas recovery device is divided into cartridges to facilitate handling and downsize the device. [Structure] The fibrous activated carbon is divided into several pieces in a cartridge type, and two or more pieces of which are arranged in tandem are arranged in parallel.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a solvent recovery device that uses a cartridge-type fibrous activated carbon.

[0002]

[Conventional technology and problems to be solved]

 CFC-113, trichloroethane, and other halogenated hydrocarbon organic solvents used in the cleaning of electronic parts and precision parts are regulated as substances that are directly attributable to ozone depletion, and the international environment Due to the above-mentioned problems, it is desired to collect them for reuse without discharging them outside the system. Therefore, various organic solvent gas recovery devices have been developed to recover these organic solvent gases that have been diffused into the atmosphere, and many manufacturers that use organic solvents have introduced or are studying their introduction. . An organic solvent recovery system is generally well known as a solvent gas adsorption system that uses an activated carbon tower system that incorporates fibrous or granular activated carbon, and in recent years, the need to recover and reuse the solvent has increased. As a result, many recovery devices have started to use fibrous activated carbon, which has a high adsorption / desorption rate and causes less deterioration of the recovered solvent than granular activated carbon.

As a basic design method of a fibrous activated carbon tower in an organic solvent gas recovery apparatus, the amount of activated carbon that corresponds to the amount of the solvent in the adsorption cycle is targeted from the concentration of the evaporated solvent gas and the gas flow rate. The operating adsorption capacity of the solvent to be used (the amount of solvent not detected from the outlet side of the activated carbon tower in the adsorption cycle) is used. Based on the amount, the final superficial linear velocity LV (Superficial Li near Velocity: value obtained by dividing the treated air volume by the cross-sectional area of the fibrous activated carbon layer) when the solvent-containing gas passes through the fibrous activated carbon is finally determined. Determine details of activated carbon and activated carbon tower dimensions. The designed fibrous activated carbon is one per activated carbon tower, and two of these towers are installed and recovered by alternate operation of adsorption and desorption. At this time, the solvent gas concentration is 1000 to 4000 ppm, which is a treatmentable concentration because the adsorption efficiency is high.

When the amount of solvent evaporated exceeds 4000 ppm, in order to adjust to a preferable gas concentration-generally, the amount of treated air is increased (diluted) to deal with it. The size is increased and the amount of fibrous activated carbon is also increased. Therefore, the fibrous activated carbon cannot be easily lifted by hand, and a heavy machine or the like is required to lift the fibrous activated carbon from the activated carbon tower when exchanging the activated carbon. In addition, if the height of the fibrous activated carbon is high and the ceiling in the room where the solvent gas recovery device is installed is low, it may come into contact with the ceiling during extraction from the tower and it may not be extracted smoothly. If there are restrictions, it will be installed outdoors and a separate building etc. will be required and incidental work will be required. Further, in the conventional method, there is a problem that the production of activated carbon towers is batch production of one tower and the cost is high, because the activated carbon towers are often made to be custom-made to design the activated carbon tower according to the amount of treated air.

[0005]

[Means for Solving the Problems]

 The present invention is an apparatus for recovering an organic solvent gas filled with fibrous activated carbon as an adsorbent, characterized by arranging two or more cartridge type fibrous activated carbons in tandem in parallel. is there.

[0006]

[Action]

In the present invention, after determining the treatment air volume from the solvent gas evaporation amount so as to reach the target gas concentration, what was conventionally treated with one fibrous activated carbon was divided into, for example, two fibrous activated carbons (treatment air volume). == 20 m ³ / min, 10 m ³ / min is processed per piece). That is, in the past, one activated carbon was designed after the target treatment air volume was determined, but in the present invention, since several cartridges are arranged in a column and the fibrous activated carbon is divided into many, Weight reduction per cartridge can be achieved. Therefore, the fibrous activated carbon cartridge can be set to a weight that can be easily replaced by hand, which simplifies the replacement work and reduces the work cost.

Further, it is possible to reduce the size of a large air flow rate recovery device due to an increase in solvent evaporation amount. Furthermore, by standardizing the cartridges, it is sufficient to mount the number of cartridges that corresponds to the amount of air to be treated, the conventional design of one activated carbon is not required, and mass production is possible, so the manufacturing cost can be reduced.

[0008]

【Example】

An embodiment of the present invention will be described below with reference to the drawings. CFC-113 (1,1,2-trichloro-1,2,2-trifluoroethane) gas transpiration amount = 20 kg / Hr, general processing gas concentration = 2000 ppm, active coal tower height = 1000 mm, adsorption cycle A description will be given of an example of collecting under the condition of 12 min. The fibrous activated carbon having a specific surface area of 1500 to 2000 m ² / g and a height of 4 to 500 mm can be preferably used, but the fibrous activated carbon is not limited thereto.

FIG. 1 is a schematic view of a conventional collecting device, FIG. 1 (A) is a plan sectional view, and FIG. 1 (B) is a longitudinal side view. FIG. 2 shows an example of the present invention. FIG. 2 (A) is a plan sectional view and FIG. 2 (B) is a vertical side view. The method of solvent recovery is the same as in FIG. 1 and FIG.

First, the fibrous activated carbons 2a and 2b are wound and fixed on the cylindrical tubes 3a and 3b whose upper portions are closed. Next, the automatic valves 4a, 4b, 5a, 5b are opened (at this time, the automatic valves 6a, 6b, 7a, 7b are closed), the gas containing the solvent is blown from the upper part of the activated carbon towers 1a, 1b, and the gas is The fibrous activated carbon 2a, 2b flows into the cylindrical tubes 3a, 3b from the outside. At this time, the solvent is adsorbed by the fibrous activated carbons 2a and 2b, and the cleaned gas passes through the lower portions of the cylindrical tubes 3a and 3b and is discharged from the clean gas outlet to the outside of the system. When the adsorption cycle = 12 minutes has passed, the automatic valves 4a, 4b, 5a, 5b are closed and the automatic valves 6a, 6b, 7a, 7b are opened to desorb the solvent. High-temperature steam is introduced from the lower part of the activated carbon towers 1a and 1b to desorb the solvent adsorbed on the fibrous activated carbons 2a and 2b and discharged from the desorption gas outlet to a post-treatment step outside the system. By installing two activated carbon towers in parallel, the adsorption and desorption of the solvent can be carried out continuously.

In the present embodiment, the air flow rate for treating the gas transpiration amount = 20 kg / Hr at the target gas concentration = 2000 ppm is 20 m ³ / min. From the amount of gas transpiration = 20 kg / Hr and the adsorption cycle = 12 min, the amount of the solvent introduced into the activated carbon tower during this period is 4 kg (= 20 × 12/60). Further, when the operation adsorption capacity of the fibrous activated carbon is 10%, the required amount of activated carbon is 40 kg. From the height of activated carbon tower = 1000 mm, the height of the activated carbon tower is set to 900 mm, and the dimension of the activated carbon tower is as shown in the embodiment of Table 1 when designed by the conventional method based on LV.

[0012]

[Table 1]

Next, in the cartridge method of the present invention, four fibrous activated carbon cartridges having a height of 450 mm are prepared, and each of them is made into one cartridge independently, and two fibrous activated carbon cartridges are connected in series and the activated carbon height is 900 mm. And Two sets of this are prepared. The amount of air flow = 10 m ³ / min, that is, 5 m ³ / min per one can be processed by one set. The design results in this case are shown in the examples of Table 1.

Another embodiment is shown in Table 1. In Table 1, the examples show the conventional method and the examples show the cartridge method of the present invention. According to the present embodiment having such a configuration, the conventional method has a weight of activated carbon of 40 kg / piece, which makes replacement by hand difficult, while the cartridge method can reduce the weight to 10 kg / piece, so that the replacement can be easily performed. In addition, the cartridge method can make the activated carbon tower size more compact than the conventional method.

The target solvent is not limited to CFC-113, but may be trichloroethane (1,1,1-trichloroethane), HCFC-141b (1,1-dichloro-1-fluoroethane), trichloroethylene, tetrachloroethylene, methylene chloride, or the like. Of course, it can be applied.

[0016]

[Effect of the device]

 As described above, according to the present invention, by arranging two or more cartridge type fibrous activated carbons in a column, the recovery device can be made compact and the weight per cartridge can be reduced. Since the weight can be easily replaced even by hand, the replacement work can be simplified and the work cost can be reduced, and the standardization of the cartridge eliminates the need for the conventional single activated carbon design. Since mass production is possible, the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 shows a plan sectional view (A) and a vertical side view (B) of a conventional recovery device.

FIG. 2 shows a plan sectional view (A) and a vertical side view (B) of the recovery device of the present invention.

[Explanation of symbols]

 1a, 1b Activated carbon tower 2a, 2b Fibrous activated carbon 3a, 3b Inner cylinder pipe 4a, 4b, 5a, 5b Automatic valve 6a, 6b, 7a, 7b Automatic valve

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Kenji Isoyama 3-7-1 Kanda Nishikicho, Chiyoda-ku, Tokyo Central Glass Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A solvent recovery device for recovering an organic solvent gas filled with fibrous activated carbon as an adsorbent, characterized in that two or more cartridge type fibrous activated carbons are arranged in tandem. .