KR102251117B1 - Apparatus for collecting solvent contained in exhaust gas - Google Patents

Abstract

The present invention relates to a solvent collection apparatus for collecting toluene and dimethylformamide contained in exhaust gas resulting from textile dyeing and manufacturing. The apparatus includes: a cooling unit liquefying toluene and dimethylformamide in exhaust gas by cooling the exhaust gas; a mixing and dissolving unit supplied with the exhaust gas containing the toluene and dimethylformamide liquefied by the cooling unit, turning the liquefied dimethylformamide into mist, and dissolving the mist in water; a gas-liquid separation unit performing gas-liquid separation after receiving the exhaust gas that has passed through the mixing and dissolving unit; an oil-water separation unit receiving an aqueous solution and the toluene liquefied at the mixing and dissolving unit and the gas-liquid separation unit and separating the aqueous solution and the liquefied toluene from each other based on specific gravity; and a solution circulation unit receiving the aqueous solution from the oil-water separation unit and causing the solution to circulate to the mixing and dissolving unit.

Description

Apparatus for collecting solvent contained in exhaust gas}

The present invention relates to a solvent recovery device for recovering toluene and dimethylformamide (hereinafter referred to as'DMF') contained in exhaust gases generated during the dyeing process of textiles.

In general, volatile organic compounds (VOCs) are hydrocarbon compounds that are easily volatilized into the atmosphere. The main emission source of volatile organic compounds accounts for more than 60% of the total emission from facilities using organic solvents. Organic solvents typically used in the workplace include benzene, toluene, and xylene.

These volatile organic compounds are easily evaporated into the atmosphere, causing a photochemical reaction with nitrogen oxides, and generating photochemical oxidizing substances such as ozone, causing photochemical smog. In addition, since volatile organic compounds adversely affect the climate environment and human health due to tropospheric ozone pollution, the cause of the stratospheric ozone layer destruction, and global warming, regulations on emission are being strengthened. In general, there are adsorption method and incineration method as technologies for controlling volatile organic compounds.

Adsorption method is widely used because of its wide application range, low cost, and easy operation management. However, this adsorption method has a problem in that it is difficult to immediately convert the adsorbed volatile organic compounds into energy. The incineration method has the advantage of being able to convert it into energy by processing it on the spot, but it has a disadvantage that an auxiliary fuel must be used.

Existing organic compound separation and recovery devices need to sufficiently recover and reuse toluene and DMF, solvents contained in the exhaust gases generated during the dyeing process of textiles, and to prevent environmental pollution. There is a problem that cannot be done.

Accordingly, the present invention has been proposed in order to solve the above problems, and an object of the present invention is to provide a solvent recovery device capable of recovering and reusing toluene and DMF contained in exhaust gases generated during the fabric dyeing process. It is in providing.

Another object of the present invention is to separate the toluene and DMF solution contained in the exhaust gas generated during the manufacturing process of textile dyeing, and discharge only the gas harmless to the human body to the outside, satisfying environmental regulations, and contained in the exhaust gas to prevent air pollution. It is to provide a solvent recovery device.

In order to achieve the object of the present invention as described above, the present invention provides a cooling unit for liquefying toluene and DMF contained in the exhaust gas by cooling the exhaust gas, and an exhaust gas containing toluene and DMF liquefied in the cooling unit. A mixing and dissolving unit that mistizes and dissolves DMF in water while being supplied and mixed, a gas-liquid separation unit that receives the exhaust gas passing through the mixing and dissolving unit and separates it into a gas and a liquid, and the mixed and dissolving unit and the gas-liquid separation Exhaust gas including an oil-water separation unit receiving liquefied toluene and an aqueous solution from the unit and separating the aqueous solution and liquefied toluene by specific gravity, and a solution circulation unit receiving the aqueous solution from the oil-water separation unit and circulating it to the mixed and dissolving unit It provides a recovery device for the solvent contained in the.

The cooling unit includes a cooling case through which the exhaust gas passes, and a heat exchanger that is accommodated in the cooling case and cools toluene and DMF contained in the exhaust gas passing through the cooling case.

The mixed and dissolving part is a dissolution case, an aqueous solution spraying part disposed inside the dissolution case and receiving and spraying water or an aqueous solution from the solution circulation part, and water or aqueous solution sprayed from the aqueous solution spraying part installed inside the dissolution case A venturi part for misting, and a liquid separation plate installed in the melting case to separate gas and liquid by colliding with the mist passing through the venturi part.

The dissolution case is installed inside the dissolution case and includes a partition wall that divides the dissolution case into a first chamber and a second chamber, and the aqueous solution injection unit, the venturi unit, and the liquid separation plate may be installed in the first chamber. have.

The gas-liquid separation unit is installed in the gas-liquid separation case, the gas-liquid separation case, and a mist separator for separating residual toluene and residual DMF mist from the gas by passing the gas supplied from the mixing and dissolving unit, and the gas-liquid separation case is installed in the mist. It includes an adsorption unit for adsorbing residual toluene and DMF mist that has passed through the separator.

The oil-water separation unit is installed inside the oil-water separation case and the oil-water separation case to maintain a constant water surface while discharging the aqueous solution to the solution circulation unit, and is installed on the upper side of the water surface holding unit to be separated by a difference in specific gravity. And a toluene recovery unit for recovering toluene.

The present invention collects and reuses toluene while passing the exhaust gas generated during the fabric dyeing process manufacturing process through the cooling unit, the mixing and dissolving unit, the gas-liquid separation unit, and the oil-water separation unit to reduce the manufacturing cost of the fiber dyeing process, It has the effect of preventing air pollution by discharging it.

In addition, if the DMF solution is repeatedly reused to obtain an aqueous solution having a sufficient DMF concentration, the DMF is recovered using a separate DMF separation device, thereby reducing the cost incurred in the fiber dyeing process.

1 is a view showing the overall configuration of a solvent recovery device contained in exhaust gas to explain an embodiment of the present invention.
2 is a view showing a main part of a cooling unit for explaining an embodiment of the present invention.
3 is a cross-sectional view taken along AA of FIG. 2.
4 is a view showing the main configuration of the absorber to explain the embodiment of the present invention.
5 is a view showing the main configuration of a gas-liquid separation unit to describe an embodiment of the present invention.
6 is an enlarged view illustrating a main part of FIG. 5.
7 is a view showing the main configuration of the oil-water separation unit to explain an embodiment of the present invention.
8 is a configuration diagram of a sensor and a control valve applied to an apparatus for recovering a solvent contained in exhaust gas to illustrate an embodiment of the present invention.
9 is a flowchart illustrating a process of recovering a solvent contained in exhaust gas to illustrate an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and the same reference numerals are assigned to the same or similar components throughout the specification.

1 is a view for explaining an embodiment of the present invention, showing an apparatus for recovering a solvent contained in exhaust gas.

The solvent recovery device included in the exhaust gas of the present invention includes a cooling unit 100, a mixed and dissolving unit 200, a gas-liquid separation unit 300, an oil-water separation unit 400, and a solution circulation unit 500. .

The cooling unit 100 includes a cooling case 101 through which exhaust gas passes, a heat exchanger 103, and a cooler 105. The exhaust gas includes toluene and dimethylformamide (hereinafter referred to as'DMF') used as solvents in the manufacturing process of textile dyeing. These exhaust gases are discharged at temperatures of approximately 90 to 110 degrees Celsius. The concentration of toluene contained in the exhaust gas is about 700~1500ppm. And the concentration of DMF contained in the exhaust gas is about 200 ~ 300ppm. In addition, toluene mixed in the exhaust gas is not soluble in water, and DMF can be dissolved in water to become an aqueous solution.

As shown in FIG. 2, the cooling case 101 has a heat exchanger 103 disposed therein. The heat exchanger 103 is connected to a cooler 105 (see FIG. 1) disposed outside the cooling case 101 to lower the temperature inside the cooling case 101. The heat exchanger 103 and the cooler 105 may use a device using a refrigeration cycle that lowers the temperature inside the cooling case 101 by using a refrigerant. The cooler 105 is installed at a location away from the cooling case 101 like a cooling tower, so that the internal temperature of the cooling case 101 can be efficiently lowered.

The heat exchanger 103 includes a plurality of refrigerant pipe passages 107 through which refrigerant passes. In addition, a plurality of cooling fins 109 are connected to the outside of the refrigerant pipe 107 to improve the heat absorbing function of the refrigerant. In addition, the refrigerant pipe 107 circulates the cooler 105 while being supplied to the bottom side of the cooling case 101 and exiting the upper side of the cooling case 103 (indicated by solid arrows in Figs. 2 and 3). . As described above, while the refrigerant circulates through the refrigerant pipe line 107, heat inside the cooling case 101 is taken away, so that the temperature inside the cooling case 101 can be drastically lowered.

This structure is advantageous in lowering the temperature inside the cooling case 101 because it circulates while always maintaining a state filled with the refrigerant in the plurality of refrigerant pipes 107.

The cooling unit 100 can rapidly lower the temperature of the exhaust gas while the above-described exhaust gas passes through the interior of the cooling case 101 and comes into contact with the refrigerant line 107 and the cooling fins 109 of the heat exchanger 103. Yes (indicated by dotted arrows in Figs. 2 and 3). When the temperature of the exhaust gas is lowered, toluene and DMF contained in the exhaust gas may change into a particulate liquid phase. In this way, DMF can be easily dissolved while in contact with water when it changes to a liquid phase in a particulate state. In addition, when the temperature of toluene is lowered, the toluene is changed to a liquid state, and thus toluene is easily recovered.

The mixing and dissolving unit 200 dissolves DMF in water or aqueous solution while the exhaust gas is cooled in the cooling unit 100 to pass a gas containing toluene liquefied and liquefied DMF particles in the form of particles. At this time, liquefied toluene is mixed with water or an aqueous solution.

The mixing and dissolving part 200 includes a dissolution case 201, an aqueous solution spraying part 203, a venturi part 205, a liquid separation plate 207, and a partition wall 209, as shown in FIG. 4. .

The melting case 201 is connected to the cooling case 101 of the cooling unit 100 through a pipe line P1 to supply the exhaust gas passing through the cooling case 101.

The dissolution case 201 has a first reservoir 211 formed in a funnel shape or a groove shape so that the DMF aqueous solution and the liquid toluene can be collected at the lower portion of the dissolution case 201. The melting case 201 is partitioned by a partition wall 209 at a center portion in the vertical direction (based on FIG. 4). The partition wall 209 divides the melting case 201 into a first chamber 213 and a second chamber 215. The first chamber 213 and the second chamber 215 communicate with each other at the lower end of the first chamber 213 and the second chamber 215, so that exhaust gas can freely pass through it. That is, the partition wall 209 separates the melting case 201 into two spaces only up to the upper portion of the first reservoir 211 side.

It is preferable that the dissolution case 201 is disposed on the upper side of the first reservoir 211 where the exhaust gas passing through the cooling case 101 is introduced and discharged. In the melting case 201, an inlet and an outlet through which the exhaust gas passing through the cooling case 101 is introduced are disposed at the top, the inlet is disposed in the first chamber 213, and the outlet is disposed in the second chamber 215. It is preferred to be arranged.

An aqueous solution spraying part 203 is installed at the upper end of the first chamber 213. It is preferable that the aqueous solution injection unit 203 is installed at the upper end of the first chamber 213. The aqueous solution spraying unit 203 may spray or spray water or an aqueous solution supplied from the solution circulation unit 500. Water or aqueous solution sprayed from the aqueous solution injection unit 203 may dissolve DMF contained in the exhaust gas.

In addition, a venturi part 205 is installed in the middle part of the first chamber 213, which is the lower end of the aqueous solution injection part 203. The venturi unit 205 may be configured by arranging a plurality of members such as a square pipe so that the corner portions are adjacent to each other and horizontally spaced at random intervals. The venturi unit 205 may increase a flow rate while passing water or an aqueous solution sprayed from the aqueous solution injection unit 203 to make droplets finer. When the water or aqueous solution refined through the venturi unit 205 is refined, the contact area between the DMF contained in the exhaust gas and the water or aqueous solution may be increased, thereby improving the solubility of DMF.

Liquid separation plates 207a and 207b are installed in the first chamber 213 of the dissolution case 201. The liquid separation plates 207a and 207b may be installed in a downwardly inclined shape on the dissolution case 201 and the partition wall 209, respectively. The liquid separation plates 207a and 207b are respectively installed on the dissolution case 201 and the partition wall 209, and are preferably disposed at different heights. The different heights of the plurality of liquid separation plates 207a and 207b are installed to maximize separation of gas and liquid while water or aqueous solution and toluene sequentially collide with the liquid separation plates 207a and 207b.

Therefore, water or aqueous solution that has passed through the venturi part 205, and toluene in a droplet state sequentially collide with the liquid separating plate 207, so that the fluid collects in the first reservoir 211, and the gas is in the second chamber 215. Go to. The gas that has moved to the second chamber 215 is delivered to the gas-liquid separation unit 300 through an outlet disposed on the upper side.

The gas-liquid separation unit 300 includes a gas-liquid separation case 301, a mist separator 303, and an adsorption unit 305, as shown in FIG. 5. The gas-liquid separation unit 300 serves to re-separate the residual toluene and residual DMF aqueous solution that may remain in the exhaust gas by receiving the exhaust gas that has passed through the mixing and dissolving unit 200.

The gas-liquid separation case 301 is connected to the dissolution case 201 through a pipe line P2 to receive the exhaust gas processed by the dissolution case 201. The gas-liquid separation case 301 includes a mist separator 303 and an adsorption unit 305 therein. The gas-liquid separation case 301 has a structure in which a second reservoir 307 in a concave shape is provided at the lower side to collect residual toluene and residual DMF aqueous solution separated from the exhaust gas. It is preferable that the mist separator 303 and the adsorption unit 305 are disposed at an arbitrary distance on both sides of the second reservoir 307 as a reference.

The mist separator 303 includes a first separation unit 309, a second separation unit 311, and a third separation unit 313. In the embodiment of the present invention, the mist separator 303 is described by showing three separate parts for convenience, but it is also possible to include one or three or more separation parts.

The first separation unit 309, the second separation unit 311, and the third separation unit 313 are each coupled to a plurality of gas separation plates 315, respectively. The gas separation plate 315 has the same structure, but it is preferable to install the first separation unit 309, the second separation unit 311, and the third separation unit 313 in different inclination directions, respectively. That is, the first separating unit 309 has a structure in which the gas separating plate 315 is continuously arranged in a downward slope, and the second separating unit 311 is a gas separating plate 315 in a direction opposite to the first separating unit 309. ) Is arranged to be inclined upward, and the third separation unit 313 may arrange the gas separation plate 315 to be inclined downward again in a direction opposite to the second separation unit 311. As shown in FIG. 6, the gas separation plate 315 is bent at the inclined surface portion 315a and the first extension portion 315b that is bent and extended from the inclined surface portion 315a, and the first extension portion 315b. It includes a second extension portion 315c extended and extended, and a third extension portion 315d bent and extended from the second extension portion 315c. The first extension part 315b, the second extension part 315c, and the third extension part 315d have three surfaces and are concave.

In addition, the inclined surface portion 315a is disposed in different directions on the first separating portion 309, the second separating portion 311, and the third separating portion 313, as shown in FIG. 5.

Therefore, the exhaust gas flowing into the gas-liquid separation case 301 first hits the inclined surface portion 315a, and is formed by the first extension part 315b, the second extension part 315c, and the third extension part 315d. As the gas and liquid are separated by flowing into the concave portion and colliding, the liquid is collected in the second reservoir 307 by gravity. And the gas passes through the adsorption unit 305. In this process, the residual toluene and residual DMF aqueous solution contained in the exhaust gas are sufficiently separated from the gas.

It is preferable that the adsorption unit 305 is made of activated carbon. Therefore, a trace amount of toluene and a trace amount of DMF aqueous solution contained in the exhaust gas pass through the adsorption unit 305. In this process, the toluene and DMF aqueous solution are adsorbed on the activated carbon, and only clean gas from which the pollutant has been removed is discharged to the outside.

The oil-water separation unit 400 receives liquefied toluene and a DMF aqueous solution from the mixing and dissolving unit 200 and the gas-liquid separation unit 300 and separates the DMF aqueous solution and the liquefied toluene by specific gravity.

The oil-water separation unit 400 includes an oil-water separation case 401, a sleep holding unit 403, and a toluene recovery unit 405, as shown in FIG. 7.

The oil-water separation case 401 is connected to the first reservoir 211 of the dissolution case 201 through a conduit P3 to receive the toluene and DMF aqueous solution collected in the first reservoir 211. A first control valve v1 may be installed in the pipeline P3 connecting the oil-water separation case 401 and the dissolution case 201. In addition, a first sensor S1 (refer to FIG. 8) may be installed in the first reservoir 211. When a certain amount of toluene and DMF aqueous solution are collected in the first reservoir 211, the first sensor S1 detects and transmits it to the controller C. That is, the controller C may transfer the toluene and DMF aqueous solution to the oil-water separation case 401 by controlling to open the first control valve v1.

In addition, the oil-water separation case 401 is connected to the second reservoir 307 of the gas-liquid separation case 301 through another conduit P4 to receive the toluene and DMF aqueous solution collected in the second reservoir 307. A second control valve v2 is installed in the pipeline P4 connecting the oil-water separation case 401 and the second reservoir 307 of the gas-liquid separation case 301. In addition, a second sensor S2 (refer to FIG. 8) may be installed in the second reservoir 307. When a certain amount of toluene and DMF aqueous solution are collected in the second reservoir 307, the second sensor S2 senses this and transmits it to the controller C. That is, the controller C may transfer the toluene and DMF aqueous solution to the oil-water separation case 401 by controlling to open the second control valve v2.

The water surface holding part 403 may be installed in the middle of the oil-water separation case 401. The water surface maintenance unit 403 maintains a constant height of the water surface of the DMF aqueous solution, and transfers the DMF aqueous solution to the solution circulation unit 500 when it exceeds the predetermined height. The water surface maintaining unit 403 includes a pipe line P5 through which the DMF aqueous solution can be moved to the solution circulation unit 500, and a control valve v3 may be installed in the pipe line p5. In addition, the oil-water separation case 401 may be provided with a third sensor S3 capable of detecting the height of the DMF aqueous solution. In addition, the sensing value of the third sensor S3 may be transmitted to the controller C. The controller C may always maintain a constant height of the DMF aqueous solution by controlling the third control valve v3 in response to the sensing value of the third sensor S3.

On the other hand, the pipe (P5) used for the water surface maintenance unit 403 may be formed of an overline type pipe that moves to the solution circulation unit 500 only if the DMF aqueous solution is more than a certain amount.

The toluene recovery unit 405 is installed above the water level of the DMF aqueous solution layer (H, see FIG. 7) held by the water surface holding unit 403. That is, the toluene recovery unit 405 is installed in the toluene layer. The toluene recovery unit 405 may be formed of a recovery pipe (P6) to extract toluene from the toluene layer (T, see FIG. 7) of the oil-water separation case 401. The specific gravity of toluene is about 0.87, and DMF is dissolved in water, so that the specific gravity of the DMF aqueous solution is higher than 1. Therefore, toluene can be easily recovered from an aqueous solution of DMF dissolved in water due to the difference in specific gravity. The recovered toluene can be reused, thereby reducing the cost of the dyeing process of the fiber.

The solution circulation unit 500 includes a solution circulation case 501. The solution circulation case 501 receives the DMF aqueous solution from the oil-water separation case 401 through the pipe P5, and the DMF aqueous solution is supplied to the aqueous solution spraying unit 203 installed in the dissolution case 201 of the mixing and dissolving unit 200 described above. Is supplied through another conduit (P7).

That is, the solution circulation unit 500 receives the DMF aqueous solution from the oil-water separation case 401 and supplies it to the aqueous solution injection unit 203. The aqueous solution contained in the solution circulation case 501 of the solution circulation unit 500 is a solution in which DMF is dissolved, and the concentration of DMF is increased according to the number of uses. Therefore, if the concentration of DMF in the DMF aqueous solution is more than 12%, the DMF aqueous solution can be recovered through a separate pipe and entrusted to an external purification company to use the purified DMF as a recycled raw material.

A DMF concentration detection sensor (S4, see FIG. 8) is installed in the solution circulation case 501. In addition, the DMF concentration detection sensor S4 may transmit the sensed value to the controller C. Then, the controller C compares the value sensed by the DMF concentration detection sensor S4 with the reference value (for example, 12%) of the DMF concentration, and displays it on the display (not shown) or a buzzer (not shown) when the condition is satisfied. ) Can sound.

A process of recovering toluene and DMF contained in the exhaust gas by using the solvent recovery device of the exhaust gas according to the embodiment of the present invention will be described as follows.

The exhaust gas discharged from the fiber dyeing process flows into the cooling case 101 of the cooling unit 100. At this time, the temperature of the exhaust gas drops sharply as it collides with the refrigerant pipe 107 and the cooling fins 109. Then, the toluene and DMF contained in the exhaust gas are changed into a liquid substance in a mist-like state. When DMF becomes a mist, it dissolves well in water or aqueous solution to increase solubility. In addition, it is advantageous to recover liquefied toluene in water or aqueous solution by a difference in specific gravity.

The exhaust gas passing through the cooling unit 100 flows into the first chamber 213 of the melting case 201 of the mixing and melting unit 200. At this time, water or aqueous solution is sprayed from the aqueous solution spraying unit 203, and the water or aqueous solution passes through the venturi unit 205, and droplets are refined. In this process, DMF contained in the exhaust gas is dissolved in water or aqueous solution. Since the water or aqueous solution that has passed through the venturi unit 205 is refined, the solubility of DMF contained in the exhaust gas is maximized. In addition, water or aqueous solution refined together with the exhaust gas sequentially collides with the liquid separation plates 207a and 207b, while the toluene and DMF aqueous solution become droplets and are collected in the first reservoir 211. Then, the remaining gaseous exhaust gas passes through the second chamber 215 and moves to the gas-liquid separation unit 300.

The exhaust gas that has moved to the gas-liquid separation case 301 of the gas-liquid separation unit 300 is separated from the first separation unit 309, the second separation unit 311, and the third separation unit 313 of the mist separator 303. As it passes, it hits each gas separation plate 315. These exhaust gases collide with the inclined surface portions 315a of the plurality of gas separation plates 315, and collide with the grooves formed by the first extension portion 315b, the second extension portion 315c, and the third extension portion 315d. Separation of the liquid takes place. The liquid separated from the gas is collected in the second reservoir 307 by gravity. Separation of gas and liquid is maximized as the exhaust gas passes through the first separation unit 309, the second separation unit 311, and the third separation unit 313 in which the direction of the inclined surface portion 315a is changed. The residual toluene and DMF aqueous solution contained in the exhaust gas are sufficiently collected in the second reservoir 307.

In addition, the gas that has passed through the mist separator 303 passes through the adsorption unit 305, while the remaining toluene and the remaining DMF are filtered by the activated carbon, and only the purified gas is discharged to the outside. Therefore, it is possible to prevent environmental pollution by completely purifying and discharging the exhaust gas.

The toluene and DMF aqueous solution collected in the first reservoir 211 of the dissolution case 201 and the second reservoir 307 of the gas-liquid separation case 301 flow into the oil-water separation case 401 of the oil-water separation unit 400 do. The toluene and DMF aqueous solution collected in the first and second reservoirs 211 and 307 may be supplied to the oil-water separation case 400 as soon as they are collected. When a certain amount is collected, the first sensor S1 and the second The controller C may control the first control valve v1 and the second control valve v2 according to the sensing value of the sensor S2 and supply them to the oil-water separation case 401.

The toluene and DMF aqueous solution collected in the oil-water separation case 401 of the oil-water separation unit 400 are kept separated from each other due to the difference in specific gravity. The DMF aqueous solution maintains a constant DMF aqueous solution layer (H) by the sleep holding unit 403. And a toluene layer (T) is formed on the upper portion of the DMF aqueous solution layer (H). The DMF aqueous solution layer (H) senses the change value of the water surface by the third sensor (S3), and the controller (C) controls the third control valve (v3) by this value to maintain a constant water surface. Is transferred to the solution circulation case 501 of the solution circulation unit 500. In addition, the toluene recovery unit 405 is separated from the DMF aqueous solution by specific gravity, and thus toluene can be recovered. Therefore, toluene contained in the exhaust gas is recovered and reused, so that the cost can be reduced during the textile dyeing process.

The DMF aqueous solution introduced into the solution circulation case 501 of the solution circulation unit 500 is supplied to the aqueous solution spraying unit 203 of the mixing and dissolving unit 200 using a pump. In this way, the DMF aqueous solution is repeatedly used until the concentration set by the DMF concentration detection sensor S4 is reached. And when the concentration of DMF exceeds 12% in the DMF aqueous solution, it is discharged to the outside and reprocessing is performed to recover DMF.

Accordingly, the present invention can sufficiently recover the DMF contained in the exhaust gas while repeatedly reusing the DMF aqueous solution until it reaches a certain concentration or higher.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and it is possible to implement various modifications within the scope of the claims, the detailed description of the invention, and the accompanying drawings. It is natural to fall within the range of.

100. Cooling unit
101. Cooling case, 103. Heat exchanger,
105. Cooler, 107. Refrigerant pipe,
109. Cooling fins,
200. Mixed dissolution,
201. Dissolution case, 203. Aqueous solution spray part,
205. Venturibu, 207a, 207b. Liquid separator,
209. Bulkhead, 211. No. 1 pool,
213. first chamber, 215. second chamber,
300. Gas-liquid separation unit,
301. Gas-liquid separation case, 303. Mist separator,
305. Adsorption section, 307. Second reservoir section,
309. first separation, 311. second separation,
313. The third separation unit, 315. Gas separation plate,
315a. Inclined section, 315b. First extension,
315c. Second extension, 315d. 3rd extension,
400. Oil-water separation unit,
401. Oil-water separation case, 403. Sleep maintenance part,
405. Toluene recovery unit,
500. Solution circulation unit,
501. Solution circulation case,

Claims (6)

A cooling unit that cools the exhaust gas to liquefy toluene and DMF contained in the exhaust gas,
A mixing and dissolving unit that receives the exhaust gas containing liquefied toluene and DMF from the cooling unit and dissolves the liquefied DMF in water by misting it in a mixed state,
A gas-liquid separation unit that receives the exhaust gas passing through the mixing and dissolving unit and separates it into a gas and a liquid,
An oil-water separation unit receiving liquefied toluene and DMF aqueous solution from the mixing and dissolving unit and the gas-liquid separation unit and separating the DMF aqueous solution and liquefied toluene by specific gravity, and
A solution circulation unit that receives the DMF aqueous solution from the oil-water separation unit and circulates it to the mixing and dissolving unit
Including,
The mixing and melting part
Melting case,
An aqueous solution spraying unit disposed inside the dissolution case and receiving and spraying water or an aqueous DMF solution from the solution circulation unit,
A venturi part installed inside the dissolution case to mist the water or DMF aqueous solution sprayed from the aqueous solution spraying part, and
A liquid separating plate installed inside the melting case and separating gas and liquid by colliding with the mist passing through the venturi part
Including,
The melting case is
It is installed inside and includes a partition wall partitioning the melting case into a first chamber and a second chamber,
The aqueous solution spraying part, the venturi part, and the liquid separating plate are installed in the first chamber,
The oil-water separation unit
Oil-water separation case,
A water surface maintenance unit installed inside the oil-water separation case to discharge a DMF aqueous solution to the solution circulation unit and maintain a constant water surface, and
A toluene recovery unit installed on the upper side of the sleep holding unit to recover toluene separated by a difference in specific gravity
Including,
The solution circulation part
The DMF aqueous solution supplied from the oil-water separation unit is continuously supplied to the aqueous solution spraying unit, and the DMF concentration of the circulating DMF aqueous solution is detected, and the detected DMF concentration is repeatedly circulated until the concentration reference value is set,
The sleep maintenance unit
It includes a pipe for moving the DMF aqueous solution to the solution circulation part, a control valve is installed in the pipe, and a sensor for sensing the height of the DMF aqueous solution and transmitting a sensing value to the controller is installed in the oil-water separation case,
The controller is
A device for recovering a solvent contained in exhaust gas for maintaining a constant height of the DMF aqueous solution by controlling the control valve to correspond to the sensing value of the sensor. The method according to claim 1,
The cooling unit
A cooling case through which the exhaust gas passes, and
A heat exchanger that is accommodated in the cooling case and cools toluene and DMF contained in the exhaust gas passing through the cooling case
A device for recovering the solvent contained in the exhaust gas comprising a. delete delete The method according to claim 1,
The gas-liquid separation unit
Gas-liquid separation case,
A mist separator installed in the gas-liquid separation case and for separating residual toluene and residual DMF mist from the gas by passing the gas supplied from the mixing and dissolving unit, and
Adsorption unit installed in the gas-liquid separation case and adsorbing residual toluene and DMF mist that has passed through the mist separator
A device for recovering the solvent contained in the exhaust gas comprising a. delete

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