JP2744878B2 - Solvent recovery device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic solvent generated from a solvent vapor generating portion such as dry cleaning, metal washing, fiber washing, etc., and particularly insoluble in water, for example, trichlorethylene, perchlor ethylene, trichlorethane, and the like.
The present invention relates to an apparatus suitable for recovering a solvent such as Freon 113, toluene, and xylene .

[0002]

2. Description of the Related Art A conventional solvent recovery apparatus of this type is disclosed in Japanese Patent Application No. Hei 4-57933 proposed by the applicant of the present invention. In this conventional apparatus, a solvent and water are separated by a specific gravity separator, and the separated water is directly sent to a steam generator via a pipe, and the separated water is heated and evaporated in the steam generator to form a solvent as steam. The solvent is sent to the adsorption tower to recover the solvent from the adsorbent again, and is used repeatedly. Specific gravity separators are used when the specific gravity of the solvent is lighter than water (such as aromatic toluene and xylene) and when the specific gravity is heavier than water (such as chlorine-based trichloroethylene, pachlorethylene, trichloroethane, and fluorine-based freon). The position at which the separated water is taken out changes.

[0003]

However, a small amount of solvent may be mixed in the separated water separated by the specific gravity separator, and the water to be used may cause chlorine ions or scales which promote metal corrosion. Calcium, silicon, magnesium and the like. For this reason, there has been a problem that the heating tube and the electric heater of the steam generator are overheated to shorten their life, and the heating tube and the protection tube of the electric heater are corroded.

Accordingly, the present invention solves the above-mentioned conventional problems, and does not degrade the performance of the steam generator even if the used water is poor water. It is an object of the present invention to provide a solvent recovery apparatus which can extend the life of the protective tube, and does not cause corrosion of the protection tube and causes less trouble.

[0005]

In order to achieve the above object, according to the present invention, there is provided a solvent recovery apparatus as described above, wherein an aeration tank, a cation exchange resin and an anion exchange resin are filled in a pipe. A resin tank is provided in series so that the aeration tank is closer to the specific gravity separator than the ion exchange resin tank. According to the invention of claim 2, in claim 1, the ion exchange resin tank is a cation exchange resin tank (hereinafter, referred to as a cation exchange resin tank)
A cation tank) and an anion exchange resin tank (hereinafter referred to as an anion tank).

[0006]

The separated water from the specific gravity separator comes into contact with the air bubbles sent from below in the aeration tank to remove a small amount of solvent (generally volatile), and then passes through the ion exchange resin tank. Sometimes ions are removed. That is, first, various ions causing scale are removed when passing through the cation exchange resin (or cation tank), and then chlorine ions causing metal corrosion when passing through the anion exchange resin (or anion tank) are removed. Removed. In this way, harmless separated water from which various ions causing scale and metal rot are removed is sent to the steam generator.

[0007]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention. Reference numeral 1 denotes an adsorption tower which contains an adsorbent a such as activated carbon and is installed on a leg 2. Reference numeral 3 denotes a dust filter, 4 denotes a fan connected to the dust filter 3, and the fan 4 is installed in communication with an upper space of the adsorbent a housed in the adsorption tower 1.

Reference numeral 5 denotes a steam generator directly connected to a lower portion of the adsorption tower 1. The steam generator 5 has a housing 6, and an overheating electric heating coil 7 is provided in an upper space in the housing 6. An electric heating coil 8 for generating water vapor is provided in the water.

A condenser 10 composed of an inner and outer double tube is wound around the upper outer periphery of the adsorption tower 1. The inner pipe of the condenser 10 is provided with an inlet 11 for supplying cooling water and an outlet 12 for draining water. One end of the outer pipe is connected to an inlet pipe 13 opened to the upper space of the adsorbent a housed in the adsorption tower 1, and the other end is a drain pipe.
Connected to 14. 16 is connected to the drain pipe 14 to connect the adsorption tower 1
Is a pipe having one end connected to the separator 16. 19 is a valve 20 disposed below the separator 16
One end of this pipe 19 is connected to a makeup water pipe 21 connected to the casing 6 of the steam generator 5. Also,
In FIG. 1, 25 is a damper for introducing gas, 26 is a damper for discharging air,
Reference numerals 27 and 28 denote temperature controllers. The temperature controller 27 is used to switch off the water vapor generating electric heating coil 8 which is always in the water when the power is turned on in a state of being exposed to the water surface due to an accident. The temperature controller 28 is provided so that when the heating coil 7 for heating becomes lower than or higher than a set temperature, the coil is turned on or off. Reference numeral 30 denotes a water level gauge for maintaining the water level in the housing 6 at a constant level, 31 denotes a solenoid valve, 32
Denotes an exhaust pipe, and 33 denotes a solvent extraction pipe.

The above configuration is the same as that of the apparatus described in Japanese Patent Application No. 4-57933. Reference numeral 41 denotes an aeration tank connected to the other end of the pipe 17, and the aeration tank 41 is a closed tank body 42.
A box body having a number of small holes formed in the bottom of the body.
43 is provided, and an external blower 44 is connected to the box. Reference numerals 46 and 47 denote a cation tank and an anion tank as ion exchange resin tanks. The bottom of the cation tank 46 is connected to the middle part of the tank body 42 of the aeration tank 41 by a pipe 48, and the bottom of the anion tank 47 is a cation tank 46. It is connected to the upper part by a pipe 49. The upper part of the anion tank 47 is connected to the other end of the pipe 19 via a pipe 50. A pipe 52 has one end connected to the top of the tank body 42 of the aeration tank 41, and the other end of the pipe 52 is connected to a pipe 53 connecting the dust filter 3 and the fan 4.

The operation of the above embodiment will be described. Damper 25,
When the fan 26 is opened and the raw gas containing the solvent vapor is introduced into the dust filter 3 by the activation of the fan 4, the raw gas is supplied to the adsorption tower 1 by applying a static wind pressure by the fan 4, and the adsorbent a The solvent vapor in the gas is adsorbed by the adsorbent a while passing through the air, and the air thus cleaned is released to the atmosphere via the exhaust pipe 32.

After a predetermined amount of the adsorbent a has been adsorbed, the dampers 25 and 26 are closed, and the water vapor generated in the casing 6 of the steam generator 5 is sent to the adsorbent a, thereby adsorbing the adsorbent a. The solvent used is desorbed.

The desorbed solvent vapor and water vapor are supplied to the introduction pipe 13
Through the passage in the outer tube constituting the condenser, condenses while passing in countercurrent with the cooling water, becomes a liquid, and flows into the specific gravity separator 16 through the drain pipe 14. , Where they are separated by a specific gravity difference. At this time, the cooling water flows in from the inlet 11 to cool the solvent vapor and steam, and is discharged from the outlet 12.

The solvent separated by the specific gravity separator 16 is taken out from the solvent take-out pipe 33 and collected. Separated water (drainage) flows into the aeration tank 41 via the pipe 17 and is blown by the lower blower. A small amount (20 to 200 ppm) of a solvent (generally volatile) is promoted and evaporated by fine bubbles stirred in the tank by air sent from 44, and the evaporated small amount of solvent is blown through a pipe 52 through a blower. 4 is sent to the pipe 53 side. The separated water from which a small amount of solvent has been removed as described above further flows into the cation tank 46 via the pipe 48, and when passing through the tank, various ions that cause scale are removed.
Next, it flows into the anion tank 47 via the pipe 49, and chlorine ions which cause metal corrosion when passing through the tank are removed. In this way, while passing through the two tanks 46 and 47, chlorine ions, calcium, silicon, magnesium and the like contained in the water are removed, and the harmless separated water is passed through the pipe 50 from the valve 20 to the pipe 20. 19, and further flows into the steam generator 5 through the makeup water pipe 21.

When the desorption is completed, the dampers 25 and 26 are opened, the fan 4 is started, a cooling gas (generally air) is introduced, and the adsorbent a is dried and cooled.

FIG. 2 shows an example in which two adsorption towers 1 having the same configuration are installed in parallel, and one specific gravity separator 16 and one steam generator 51 are installed in common with these adsorption towers. It is. That is, the specific gravity separator 16 is provided so as to be connected to the condensers 10 of the first and second adsorption towers 1 and 1 by the pipes 54 and 55 . In addition, each condenser 10 can be independent from each adsorption tower 1, and one can be commonly used for each adsorption tower. Further, a steam generator 51 is provided so as to be connected to lower portions of the first adsorption tower 1 and the second adsorption tower 1 by pipes 56 and 57, and the pipes 56 and 57 are provided.
The three-way valve 58 is installed at the connection part of the. Specific gravity separator 16
The pipe 61 the aeration tank 41 is connected to, the該曝gas tank are sequentially connected cations tank 46 and an anion chamber 47, an anion
The tank 62 is connected to a pipe 62 of the steam generator 51. A blower 44 is connected to the aeration tank 41. A pipe 52 connects between the aeration tank 41 and a pipe 53 of the fan 4. 64
Is the pump installed in the pipe 62, 65 in the steam generator 51
Denotes a steam generation chamber, in which a steam superheating coil 66 and a steam generation heating coil 67 as electric heaters are vertically arranged. 68 is a liquid level gauge (controller), 70 is a thermometer for preventing emptying, and 71 is a thermometer for preventing overheating.

Reference numeral 73 denotes a solvent recovery tank connected to the specific gravity separator 16 by a pipe 74, and reference numerals 76 and 77 denote the first adsorption tower 1 and the second adsorption tower 1.
An exhaust pipe 78 connected to the exhaust pipe 32 is a supply pipe for cooling water, and valves 80 and 81 are provided near each adsorption tower 1. 83 is a return pipe for cooling water. The operation and stop of the first adsorption tower 1 and the second adsorption tower 1 can be alternately switched by a control member (not shown).

An example of the operation of this embodiment will be described below. In this example, the raw gas containing the solvent is supplied into the first adsorption tower 1 through the duct filter (not shown) by opening the dampers 25 and 26 of the first adsorption tower 1 and starting the fan 4. Only the solvent is adsorbed by the adsorbent a in 1 and the clean air is discharged to the atmosphere via the exhaust pipes 32 and 76. And 1
When the adsorption time by the adsorption tower 1 becomes longer, the amount of solvent in the adsorbent a increases, and the solvent is gradually exhausted from the outlet of the adsorption tower. Before the breakthrough time, the control member stopped the operation of the No. 1 adsorption tower 1,
The operation is switched to the second adsorption tower 1. When the adsorption by the first adsorption tower 1 is completed, the solvent is desorbed from the adsorbent a. Sent to The water vapor and the solvent desorbed by the water vapor are cooled in the condenser 10 and liquefied. The liquefied mixture (solvent and water) is sent to the separator 16 via the pipe 54 , separated into a solvent and separated water by specific gravity separation, and the solvent is collected in the recovery tank 73 and reused. On the other hand, the separated water is sent to the aeration tank 41 via the pipe 61. This separated water contains a trace amount of dissolved solvent.

A small amount of solvent is removed from the separated water flowing into the aeration tank 41 by the fine bubbles stirred in the tank as described above, and the separated water from which the solvent has been removed is further added to the cation tank 46.
When passing through the anion tank 47, various ions causing scale are removed, and when passing through the anion tank 47, chloride ions causing metal corrosion are removed. Then, the harmless separated water flows into the steam generator 51.

In each of the above embodiments, the cation tank 46 and the union tank 47 are described as the ion exchange resin tanks. However, this is only a preferred example, and may be replaced with other equivalent members. Further, it is not always necessary to use a plurality of tanks as in the embodiment.

[0021]

According to the first and second aspects of the present invention, even if the water used in the apparatus is inferior, the performance of the steam generator is not degraded, and therefore the solvent is recovered. The effect is not diminished. In addition, the life of the heating tube of the steam generator, etc. can be extended, and the protection tube is not corroded and there are few failures. There is an excellent effect that can be.

[Brief description of the drawings]

FIG. 1 is a partially broken front view showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part showing another example of the steam generator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Adsorption tower 3 Dust filter 4 Fan 5 Steam generator 7 Electric heating coil for superheating 8 Electric heating coil for steam generation 10 Condenser 16 Specific gravity separator 17, 19, 48, 49, 50 Piping 41 Aeration tank 46 Cation tank 47 Anion tank

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI B01D 53/81

Claims (2)

(57) [Claims] 1. A steam generator is provided at a lower portion of a solvent adsorption tower,
And a condenser is provided in the adsorption tower, a specific gravity separator connected to the condenser is provided, and a pipe for supplying water separated from the specific gravity separator to the steam generator is provided. The aeration tank and an ion exchange resin tank filled with a cation exchange resin and an anion exchange resin are provided in series such that the aeration tank is closer to the specific gravity separator than the ion exchange resin tank. Solvent recovery device. 2. The solvent recovery apparatus according to claim 1, wherein the ion exchange resin tank comprises a cation exchange resin tank and an anion exchange resin tank.