KR100426973B1 - One Tower Adsorb. Desorb Type Adsorption Tower - Google Patents

Abstract

The present invention proposes to construct a system with excellent economic efficiency in removing volatile organic compound vapor (VOC) evaporated from paint during paint painting and drying process with high efficiency. First, the application of the present invention alternates painting and drying operations in one place. It is applied to all the facilities consisting of the facility and the second VOC generating facility that performs the discontinuous work. For example, the painting booth that only paints works 8 hours a day or 24 hours a day, 6 days a week and then rests on Sunday. Applies to facilities with discontinuous work.

The VOC removal method generated in the facility has a number of methods, but the adsorption method suitable for large capacity, low concentration and the catalytic combustion method suitable for small capacity and high concentration are applied, but the economical system was devised by supplementing the problems of the conventional method in the treatment system application. .

In the case of facilities that alternate the painting and drying operations, which are the first application facilities, the activated carbon non-regeneration adsorption method (the third method), which is the most used as a conventional method, consumes activated carbon due to the continuous adsorption of VOC, resulting in tens of millions of annual activated carbon replacement costs. There is a problem that the economy falls due to the won.

In order to compensate for this, the main problem of the third degree method is to adopt the method of treatment by the adsorption method during the painting work and the catalytic combustion method using the small capacity and the high concentration during the drying work. By reducing the replacement cost of activated carbon to about 1/4, it has better economic efficiency than the third degree method.

However, even though this method has significantly reduced the cost of replacing activated carbon, it is still burdensome and is not seen as the most economical way.

By adopting a system that can regenerate and use activated carbon every day by adopting a method that can adsorb and desorb, the method of using low activated carbon consumption is applied.However, the existing adsorption and desorption method uses two units. Part 5 desorption method (figure 6 method) during the adsorption using the rotary cylinder (figure 5 method) is more expensive than the method of FIG. 4 by offsetting the operation cost reduction effect by reducing the consumption of activated carbon due to the high equipment cost. Can not be seen.

Therefore, the present invention is focused on the fact that even if the temperature is 150 ℃ or more, even if it contains a large amount of VOC is not adsorbed at all in the activated carbon layer, but rather desorbed VOC that is adsorbed by vaporizing the exhaust gas during drying to 150 ℃ or more desorption After the process, the VOC generated during drying and the VOC generated during desorption were simultaneously treated in a catalytic combustion device to design a system that can be treated with one general adsorption tower. Thus, the cost of equipment is significantly lower than that of the 5th and 6th methods, and the operating cost almost eliminates the consumption of activated carbon, which is an advantage of the adsorption and desorption method. This solves the problem of the conventional method.

Second, the method of FIG. 8 is applied to a facility that is operated after stopping for a certain period of time. Part of the method of FIG. 8 is modified to adsorb and operate during operation, and to desorb during operation. The VOC generated during desorption is a catalytic combustion processing facility. .

Therefore, the application of this method is widely applicable.

For example, it is applied when working 8 hours a day in a painting booth.

Description

One tower adsorption and desorption system adsorption tower Desorb Type Adsorption Tower}

Exhaust gases emitted from various facilities such as paint booths and drying furnaces, laundry facilities, and printing facilities contain volatile organic compound gases such as toluene and xylene (hereinafter referred to as VOC). It is causing air pollution.

In order to prevent air pollution due to such VOCs, various types of purification facilities are used, but most of them use the most economical and efficient activated carbon adsorption method.

However, activated charcoal is saturated when VOC is adsorbed to a certain amount and can not be adsorbed anymore, so it can be replaced at regular intervals or used again after desorption and regeneration using hot air.

In this case, if there are several production processes that can produce the same quality when producing a certain product, the production equipment cost will be low and the operation cost in production will be reduced. Moreover, even if the unit machine method is the old method, it would be highly desirable if the new system could reconstruct the system configuration and drastically reduce the production cost compared to the old system. The present invention is designed to cover all the facilities where painting and drying is performed in one place regardless of partial operation, such as 24 hours a day, 365 days a day continuous operation, or 8 hours a day, such as automobile paint booth, which is a part of VOC discharge facility. As a facility to be applied for VOC removal, by inventing the system with new ideas by using the activated carbon adsorption method and catalytic combustion method that have been used so far, economical method with low equipment cost and operation cost while maintaining high efficiency of VOC removal (Fig. 7) Method 8, which is a slightly modified version of the proposed method, can be applied to all VOC-generating facilities, which can be applied to facilities that work 8 hours a day, or work that takes a rest on Sunday after working 24 hours a week, 6 days a day. This is the case, for example, a painting booth that only paints is discontinuous.

This method is activated carbon adsorption treatment during operation, desorption by hot air during operation, and catalytic decomposition treatment of VOC generated during desorption by catalytic combustion device.

This method also has the same advantages as the seventh method.

In order to explain the system of the present invention, the activated carbon adsorption method and the catalytic combustion method are described as follows.

(1) Activated carbon adsorption method

Activated carbon has many fine pores and a large surface area. When VOCs with high molecular weight such as benzene, toluene, and xylene gas pass through the activated carbon layer, organic gas molecules flow into the micropores by van der Waals forces, and the saturated vapor pressure above It is adsorbed in a condensed state by maintaining a high concentration. This adsorption characteristic means that the VOC is continuously adsorbed and has a limited characteristic that can not be adsorbed anymore. This means that the activated carbon introduced into the adsorption column is no longer able to remove the VOC when the activated carbon is saturated. It must be replaced or removed and reused.

The desorption process for desorption and reuse of activated carbon may be performed by applying hot air or steam of 100 ° C. or higher because the VOC adsorbed on the surface of the activated carbon in the liquid phase is evaporated and desorbed by the boiling point of the boiling point to restore the activated carbon micropores to their original state.

1 shows the relationship between the adsorption concept and the adsorption efficiency of the activated carbon non-regeneration adsorption tower, which replaces the activated carbon when it is saturated, and FIG. 2 shows the relationship between the adsorption concept and the adsorption efficiency of the adsorption / desorption system.

In FIG. 1, adsorption is carried out in the Z _i layer at the initial stage of the adsorption, and then gradually becomes saturated, the adsorption zone moves upwards, and when the replacement cycle is reached (usually 3 to 6 months), the adsorption efficiency begins to decrease, and the activated carbon is replaced. .

In the second adsorption / desorption method, an adsorption zone Z that can maintain a constant efficiency in addition to the activated carbon layer Z _o required by VOC adsorption during the adsorption cycle is required.

Initial Z _i layer mainly consisting of the absorption is reached in the elapsed period adsorbed to move up while (usually 10 hours) time Z _i layer is moved to the Z _o and is changed this time to the desorption process.

(2) catalytic combustion method

The catalyst is composed of platinum, palladium, etc. It does not directly participate in the reaction, but lowers the activation energy of the reactant to promote the reaction, which is much lower than the combustion oxidation temperature of VOCs such as toluene and xylene at 600 ~ 800 ℃. It is a material that enables energy saving by enabling combustion oxidation at 150 ~ 350 ℃. The catalytic combustion method is a method of using such a catalyst to raise the temperature to 150 ~ 350 ℃ capable of combustion decomposition through the catalytic layer to remove the combustion by the reaction scheme is as follows.

Oxidative decomposition efficiency depends on VOC type, gas temperature, catalyst type and amount. Toluene and xylene, which are the main VOCs of paint, are decomposed at 150 ℃ and decompose more than 90% at 250 ℃.

As shown in the above reaction, when the inlet temperature of the catalyst bed passes at about 180 ° C, the gas temperature rises due to VOC's own heat of oxidation, and the degree of increase is proportional to the VOC concentration. Toluene + xylene concentration is 2000 ppm (based on C ₆ H ₆ and CH ₄ ) In case of 10,000ppm), it is possible to process more than 98% because it is upper layer up to about 350 ℃ and up to 350 ℃.

(3) Operation condition

In order to select a treatment plan for a facility for painting and drying work in a booth related to the present invention and to examine the economic feasibility of each method, some criteria are required. Same as

Automotive coating booths are used for the top coat, top coat and clear painting and drying after painting in the closed coating booth as shown in Fig. 3. The painting work is performed by the operator using a spray gun. In consideration of the configuration, the air supply fan 2 and the exhaust fan 3 are operated to provide ventilation.

At this time, the amount of exhaust gas increases as the size of the booth becomes larger due to the working environment, but the amount of exhaust gas of about 400 m 3 / min is required in the case of an automobile booth.

Air pollutants include paint mist that is scattered during spray painting and VOCs from the evaporation of paint solvents during the painting process are exhausted.

After painting, the painted paint drying process is carried out. The drying temperature is dried at 80 ℃.

During drying, the room temperature must be kept high, so the exhaust volume is minimized in consideration of heat loss, but the exhaust volume is exhausted to the extent that the drying effect is not reduced due to the high indoor VOC concentration. ㎥) is usually maintained at about 10 ㎥ / min.

The operation method during drying supplies heat to the drying heat supply pipe 13 through the operation of the burner in FIG. 3 while the circulation opening / closing damper 24 is completely opened while the air supply fan inlet opening / closing damper 22 is closed. When the air supply fan 2 is operated while the exhaust fan 3 is stopped, the air supply fan 2 is configured to dry while circulating indoor air.

As air pollutants during drying, VOCs evaporated during drying are contained in the exhaust gas and discharged.

The paint mist generated at the time of painting is removed by the filter 11 provided in the bottom exhaust port of the paint booth, and the filter 12 behind the exhaust fan 3.

Currently, most VOC removal facilities are not installed, and in order to quantify equipment costs and operation costs by system and to examine the advantages and disadvantages in detail, the above detailed driving conditions and VOC emission characteristics are summarized. Table 1 is attached.

(4) Outline of VOC treatment method

The method that can be treated by the prior art in the treatment of this VOC discharge facility is shown as follows.

(A) Non-removable adsorption method (figure 3)

As shown in FIG. 3, the activated carbon is charged in a simple container in the simplest manner, and the adsorption is removed by passing the VOC therein.

The problem with this method is that the activated carbon is consumed continuously, so the biggest problem is that the activated carbon replacement cost is excessive.

(B) Adsorption method and catalytic combustion method by work (figure 4)

As shown in FIG. 4, the coating is treated with activated carbon adsorption and the drying is carried out with catalytic combustion.

In other words, it selects an appropriate treatment method according to the discharge characteristics. It is discharged at low temperature, large capacity, and low concentration in the case of painting work. Therefore, it is discharged at high temperature, small capacity and high concentration in the case of drying work. This is how you handle it.

This method is superior to that of FIG. 1 in terms of efficiency by separately treating high efficiency during drying, but there is no problem of excessive replacement cost of activated carbon because there is no desorption and regeneration device as in FIG.

However, since activated carbon replacement costs only adsorb VOCs generated during painting, the activated carbon replacement costs are as low as 40-60% of the third degree method.

(C) 2 vessel type adsorption / desorption method (figure 5)

5 is adsorption that has been used before. It is composed of two adsorption towers and one desorption system while one adsorption system is used as a desorption method, which allows continuous operation with less activated carbon by desorption and regeneration after VOC adsorption. In more detail, the system opens the inlet opening / closing damper 42 and the outlet opening / closing damper 43 of the single adsorption tower during the painting operation in FIG. 5 to exhaust the exhaust gas through the activated carbon layer to the stack 5 to form the VOC. At the same time, the other one is the high concentration of VOC discharged by desorption after desorption by introducing steam through the inlet inlet valve 44 when desorption in the state in which the inlet opening and closing damper 42 and the outlet opening and closing damper 43 is closed. After the condensation is removed from the cooling condenser 402, the condensed liquid in the oil / water separator 403 is configured to be separated into a VOC condensate and water.

This method requires less activated carbon due to desorption, but the structure of system and equipment is complicated, and the cost of equipment is criticized due to the use of corrosion-resistant materials such as stainless steel by the use of steam. It also has the disadvantage of requiring separate utilities for steam and coolant.

Because of this problem, sub-types have been used only when the generated VOCs are high in concentration and have economic value in recovery.

(D) Rotary cylinder type adsorption / desorption and catalytic combustion (figure 6)

This method was developed in a foreign country recently to solve some of the disadvantages of the method of FIG. 5, and 6 compartments in the rotating cylinder 411 filled with activated carbon divided into 8 compartments in the coating process of FIG. When the desorption is made in one compartment, it is desorbed by hot air heat exchanged through the exhaust line, and the other one is configured to cool by outside air.

When operating in such a state and reaching a certain time, the rotating cylinder is rotated and the desorption-cooled compartment is adsorbed, and the last adsorbed compartment is desorbed.

The high concentration of VOC desorbed by the hot air is configured to be exhausted to the stack 10 after being removed by the catalytic combustion device through the exhaust line during the desorption.

In the drying operation, the gas heated after being treated by the catalytic combustion device through the drying exhaust line is used as drying heat and exhausted to the stack 11.

This method has the advantage that the activated carbon consumption cost is low because the adsorption and desorption and regeneration can be performed simultaneously in the facility which is continuously operated for more than 24 months continuously, but the disadvantage of the expensive equipment cost is high because the rotating cylinder and the accessory facility are expensive.

(5) Economic review by each method

(A) Non-removable adsorption method (figure 3)

① Equipment cost

㉮ Adsorption tower body and auxiliary facilities

The equipment cost is largely shown in FIG. 3 in the adsorption tower body 4, activated carbon 41, adsorption tower exhaust fan 401 (additional exhaustion is necessary due to increased pressure loss due to the adsorption tower installation), electric panel and wire construction for fan operation, etc. Air intake fan (6), connecting duct and damper, foundation work, general management costs, etc.).

The main body of the adsorption tower is about 20,000,000 won for the 400 ㎥ / mim capacity in the design standard Table 1, and about 4,000,000 won for the exhaust fan (400 ㎥ / min × 150 mmAq × 19 kw), electric facilities, and about 6,000,000 won.

㉯ activated carbon value

Activated carbon varies depending on the replacement cycle.

Q _AC : Initial activated carbon input, kg

q _v : VOC emissions in one painting work + VOC emissions in one drying work

1.35 + 3.15 = 4.5 kg / time in Table 1

n: Number of tasks per day, 5 times / day from Table 1

N: replacement cycle, 3 months × 25 days / month = 75 days

q _AC : VOC adsorption per kg of activated carbon, 0.3 kg / kg-AC

C _AC : Input activated carbon value

C: activated carbon unit price, 1,500 won / kg

∴ CAC = 5,625 kg × 1,500 won / kg

≒ 8,400,000KRW

② annual operating cost

Annual operating costs can be largely divided into annual activated carbon consumption costs, power costs, and other (activated carbon replacement labor costs).

㉮ Activated carbon consumption

Activated charcoal consumption can be applied to the annual operating days of 300 days instead of the replacement cycle N in the formula

Here, the initial unit cost of activated carbon when using fresh charcoal and reconstructing 3 times from outside company is as follows.

Activated carbon unit price C = 1,500 won × 1/4 + 800 won (recycling cost) × 3/4

≒ 1,000 won / kg

In the formula

C _AC = 22,500 kg × 1,000 won / kg

= KRW 22,500,000

㉯ Power cost

Exhaust fan 401 operating power ratio during painting

19 kw × 100 minutes / day (from Table 1) × 1/60 × 300 days / year × 50 won / kwh

≒ 500,000 won

Operation ratio of operation of drying exhaust fan (6) during drying operation

6 kw × 300 minutes / day (from Table 1) × 1/60 × 300 days / year × 50 won / kwh

≒ 500,000 won

TOTAL power cost = 500,000 + 500,000 = 1,000,000 won

㉰ Activated carbon replacement cost Others 1,000,000 won

The above summary is shown in Table 2.

(B) Adsorption method and catalytic combustion method by work (figure 4)

① Equipment cost

㉮ adsorption tower body

The main body of the adsorption tower is 18,000,000 won, which is somewhat lower than the third degree method because the amount of activated carbon is reduced compared to the third degree method.

㉯ activated carbon value

Initial activated carbon input ratio: ① In the formula, qv is adsorbed only during painting work. Qv: VOC emissions per painting, 1.35 kg / time in Table 1

The other coefficients are the same as in the method of Figure 3 (calculation omitted), so Q _AC = 1,687 kg

In the formula

_AC C _AC = 1,687 kg × 1,500 won / kg

≒ 2,500,000 KRW

㉰ Absorption fan exhaust fan and electric facility

Method 3 and Daedongso: 4,000,000 won

㉱ catalytic combustion tower

Catalytic combustion tower has a capacity of 10 ㎥ / min and a catalyst value of 7,000,000 won.

㉲ other

Much the same as the third degree method.

② annual operating cost

㉮ Activated carbon consumption

q _v = 1.35 kg / time to calculate the same way

Q _AC = 6,750 kg

_AC C _AC = 6,750 kg × 1,000 won / kg (using 3 regenerations)

≒ 6,700,000KRW

㉯ Power cost

Same as the third method for painting work: 500,000 won

Drying Exhaust Fan (6) 1 kw

TOTAL 600,000 won

㉰ Catalyst replacement ratio

Since there is no catalyst poison, it is 7,000,000 won / 4 years ≒ 1,700,000 once per 4 years

㉱ Additional fuel costs

The amount of heat to be input for system operation in the material and heat balance of FIG.

h ₁ = stack exhaust heat "g"-VOC decomposition heat "d"

= Burner supply heat "b"

= 250 kcal / min

In this case, even if there is no VOC treatment facility, dry heat must be supplied through the boiler.

h ₂ = h ₁ -drying heat "f"

= 250 kcal / min-241 kcal / min

=-9 kcal / min (ignored)

In other words, the burner operating heat and the drying heat are almost the same, so that the heat required for the operation of the catalytic combustion device is recovered as the drying heat and offset, so there is no additional supply heat.

㉲ other

Other costs such as activated carbon replacement labor cost 500,000 won, which is 1/2 of the third degree method since the amount of activated carbon replacement is smaller than that of the third degree method.

The above summary is shown in Table 2.

(C) 2 vessel type adsorption / desorption method (figure 5)

① Equipment cost

㉮ adsorption tower body

The adsorption tower main body has a small amount of activated carbon, which reduces the main body size.

15,000,000 won / unit × 2 units = 30,000,000 won

㉯ activated carbon value

In Figure 2, the amount of activated carbon (Z _o )

q _v : average VOC emissions per coat, 0.0675 kg / min from Table 1

Na: adsorption cycle = 1 day coating time, 100 minutes from Table 1

q _AC : VOC adsorption amount per kg of activated carbon, 0.3 kg / kg-AC

In addition, it depends on the adsorption zone Z necessary for the adsorption efficiency. The adsorption zone required for 90% of VOC requires 0.1 second of residence time.

Q: Exhaust gas amount during painting, 400 ㎥ / min in Table 1

v: flow rate through activated carbon layer, m / sec

d: activated carbon layer thickness, m

t _o : residence time of activated carbon layer, 0.1 sec

Activated carbon input Q _AC = Q _AC-Zo + Q _AC-Z = 22 + 350 = 370 kg

C _AC = 370 kg × C

C: Unit price per kg of activated carbon, 1,500 won / kg

∴ CAC = 550,000 won × 2 units (2 adsorption towers) = 1,100,000 won

㉰ Absorption fan exhaust fan and electric facility

Increasing costs due to complex electrical system: 6,000,000 won

㉱ Cooling condenser and oil separator

Material stainless steel standard: about 20,000,000 won

㉲ other

There are many pipes and connecting ducts, and so on.

② annual operating cost

㉮ Activated carbon consumption

Replacement when efficiency decreases due to repeated repeated use of adsorption and desorption

C _AC = KRW 1,100,000

㉯ Power cost

4th Method and Daedong Soi: 600,000 won

㉰ Steam and coolant consumption

3,000,000 KRW

㉱ other

Method 4 and Daedongso: 500,000 won

(D) Rotary cylinder type adsorption / desorption and catalytic combustion (figure 6)

① Equipment cost

㉮ adsorption tower body

The structure of the revolving cylinder is difficult and the cost of the main body is rather expensive due to the revolving cylinder driving device: 26,000,000 won

㉯ activated carbon value

Same as Method 5: 1,100,000 won / unit × 1 unit = 1,100,000 won

㉰ Absorption fan exhaust fan and electric facility

Method 5 and Daedongso: 5,000,000 won

㉱ catalytic combustion tower

Same as the way in Fig. 5: 10,000,000 won

㉲ other

8,000,000KRW

② annual operating cost

Same as the fifth way

However, the replacement cost of activated carbon is more expensive than the method of FIG. 5 due to the difficulty in replacing activated carbon.

In Table 2, the third method is simple, but because the VOC generated during coating and drying are all treated in the adsorption tower, and the non-desorbing method, the consumption ratio of activated carbon is 22,500,000 won per year, which is the least economical. In the fourth degree system, the annual activated carbon consumption cost is significantly reduced to 30% of the third degree method by treating only VOC generated during painting, but also a burden of 6,700,000 won per year.

5 and 6 are both desorption systems, which are similar in economical efficiency and have a significant reduction in the cost of activated carbon.

However, the method of FIG. 5 is more expensive than the method of FIG. 6 and consists of two systems, so the installation space is large and the system is complicated, which is likely to fail.

The method of FIG. 6 is a one-piece system, which is smaller in size and relatively simpler than the system of FIG. 5, but has no installation experience in Korea, is difficult to replace activated carbon, and is more difficult to maintain and maintain such as a rotary cylinder drive system.

As mentioned above, the economics of each method have been reviewed. Of course, it should be noted that since the economics are calculated based on the operating conditions of Table 1, the economic conditions also vary when the operating conditions are different.

Nevertheless, the third-degree method is disadvantageous compared to other methods due to the consumption of activated carbon, unless the amount of paint or operation time is drastically reduced and the VOC emissions are reduced to less than 1/5 of the conditions in Table 1. In addition, if the VOC emissions are reduced due to less paint usage or operating time than Table 1 conditions, the fourth degree method is more advantageous than the fifth and sixth method, while the VOC and sixth method are increased when the VOC emissions are increased. It is necessary to consider this even more advantageous.

In conclusion, though, depending on the conditions, there may be some way or disadvantage in economics, but there is no way that any one method emerges remarkably.

In other words, when comprehensively examined, it means that there is no superior method compared to other methods at present.

The present invention considered the following technical problems in the VOC treatment method of the installation and painting work in a booth.

(1) The design of a method that has excellent economic efficiency by drastically lowering in terms of equipment cost and annual operating cost of treatment method

[Table 2] Economic Comparison by Method

(2) devising a way to maximize the economic benefits by saving energy by applying the utilization of heat energy to the maximum.

(3) The design of installation method that can be installed in limited space is 50% smaller than existing method

(4) The design of a method of easy maintenance and repair, such as the possibility of failure due to the simple processing system and the ease of replacement of activated carbon

(5) VOC removal facilities that perform discontinuous work in addition to the facility where painting and drying work alternately in one booth. For example, the VOC treatment method of the coating booth facility that only discontinuous work is economical, installation area, maintenance and repair. Devising the optimal way

1 is a conceptual diagram of adsorption concept and adsorption efficiency of the non-removable adsorption method.

2 is a conceptual diagram of adsorption concept and adsorption efficiency of adsorption / desorption adsorption method.

3 is a flow chart of the non-removable adsorption method

4 is a flow chart of non-desorbable adsorption method and catalytic combustion method for each job.

5 is a flow chart of a two tower type adsorption / desorption method

6 is a flow chart of the rotary cylinder type adsorption / desorption method and catalytic combustion method.

7 is a one-top adsorption. Flow chart of desorption method (booth that alternates painting and drying)

8 is a one-top adsorption. Desorption flow chart (facility stops after a certain time)

9 is the balance of materials and heat balance during the drying process (Figs. 4 and 6).

10 is the balance of materials and heat balance during the painting process (figure 5 and 6).

Figure 11 shows the balance of materials and heat balance during the drying process (Figure 7).

* Explanation of symbols for main parts of the drawings

One … Paint booth 11. Mist elimination primary filter

12... Mist removal secondary filter 13 .... Dry heat supply piping

2 … Booth air supply fan 21. Air supply flow control damper

22. Air supply fan opening and closing damper 23. Supply fan inlet filter

3…. Booth exhaust fan 31. Exhaust Fan Inlet Damper

4 … Adsorption tower 401... Adsorption tower exhaust fan

402 .. Cooling condenser 403 ... oil-water separator

41…. Activated carbon 411... Tumbler

412. Rotary cylinder drive 42. Adsorption tower inlet opening and closing damper

43. Adsorption tower outlet switch damper 44. Removable Hot Air Inlet Opening and Closing Valve

45.. Removable hot air outlet open / close valve 5. Adsorption tower stack

6. Dry gas exhaust fan 61. Dry gas exhaust fan inlet valve

(Removable Hot Air Fan) (Removable Hot Air Fan Inlet Valve)

7. Catalytic combustion apparatus 71. Burner or electric heater

72. Catalyst 8. heat transmitter

91. Detachable hot air supply switch valve 92. Catalytic Combustion Gas Opening Valve

100... Catalytic Combustion Gas Exhaust Pipe

The present invention was reconstructed using the conversion of ideas using activated carbon adsorption principle. In other words, if it is possible to use the gas released during the drying process as desorption heat, the adsorption is carried out during the coating and the activated carbon desorption process is carried out at the same time as the drying process.

In general, activated carbon adsorption lowers the temperature of the VOC gas introduced into the micropores by van der Waals force from the micropores easily condensed and adheres to the surface of the activated carbon. That is, the lower the gas temperature, the better the adsorption.

However, if the gas temperature rises above 40 ℃, the VOC saturation vapor pressure in the micropores rises and the VOC condensation is not well achieved, so the adsorption efficiency starts to drop sharply and no adsorption occurs at the gas temperature above the VOC boiling point. In addition, if there is a VOC adsorbed on the activated carbon layer, the VOC of the microporous surface is evaporated to desorption.

Taking advantage of this, when constructing the system as shown in FIG. 7, when the dry gas containing a large amount of VOC dried and exhausted from the paint booth is heated up to 200 ° C. and passed through the activated carbon layer, the VOC contained in the dry gas is not adsorbed at all. Rather, the adsorption of VOC adsorbed at the time of coating, the VOC generated at this time and the VOC contained in the air dry gas are treated together in the combustion catalyst device, it is possible to complete the treatment with one adsorption tower.

Hereinafter, with reference to the accompanying drawings, Figure 7 described in detail the technical configuration for achieving the object of the present invention.

In FIG. 7, during the painting operation, the air supply fan inlet / opening damper 22, outlet damper 21, and adsorption tower inlet opening / closing damper are closed in a state in which the circulation opening and closing damper 24 of the circulation duct 9 is closed during drying. When the air supply fan 2, the booth exhaust fan 3, and the adsorption tower exhaust fan 401 are operated with the 42 and outlet opening and closing dampers 43 open and the drying exhaust fan inlet damper 61 closed, the air supply fan filter ( 23, the outside air is introduced to ventilate the interior of the paint booth, and is exhausted to the stack 5 through the adsorption tower (4).

At this time, the paint mist generated during the coating is removed from the primary filter 11 and the secondary filter 12, and the VOC generated during the coating is removed from the adsorption tower (4).

In the drying operation, the circulation duct opening and closing damper 24 is opened during drying, the air supply fan inlet opening and closing damper 22 is closed, the adsorption tower inlet opening and closing damper 42 and the outlet opening and closing damper 43 are closed, and the drying exhaust fan inlet damper 61 is closed. Open (exhaust fan (3) is inactive),

If the air supply fan 2, the dry gas exhaust fan 6 and the burner 71 of the catalytic combustion device 7 are operated with the adsorption tower desorption hot air inlet open / close valve 44 and the outlet open / close valve 45 opened, the burner 71 is dried. A large amount of hot air containing heat circulates in a line consisting of a circulating duct and an air supply fan during drying and flows in as much as an exhaust amount of the dry exhaust fan (10 m 3 / min) by suction of the drying exhaust fan 6 so that the heat exchanger 8 , Adsorption tower hot air inlet valve (44), activated carbon in the adsorption tower (41), adsorption tower hot air outlet valve (45), catalytic combustion device (7), dry heat supply piping in the booth, heat exchanger (8), stack 10 Exhausted.

At this time, when air at room temperature contains VOC remaining in the paint booth and flows through the drying exhaust fan to the adsorption tower, it is adsorbed there and then the gas temperature is rapidly increased by the burner heat of the catalytic combustion device. At the same time as supplying the temperature of the hot air flows into the hot air inlet valve 44 through the heat exchanger is heated and the desorption occurs in the adsorption layer.

After a certain period of time, the VOCs generated by drying in the booth and VOCs generated by desorption of activated carbon are decomposed and operated at the temperature shown in FIG. 7 while supplying drying heat and desorption heat without burner supply heat. .

Like this, the facility where painting and drying are repeated on treatment flow is a facility that can handle all facilities, such as a facility that operates continuously for 24 hours and 365 days, as well as a partial operation facility after a certain time of operation.

Since the facilities that do not distinguish between painting and drying work cannot be handled by the system, the painting and drying processes are not distinguished, such as facilities that keep painting only or facilities with multiple small facilities among those that repeat painting and drying. The facility cannot be handled in the manner of FIG. 7.

However, it is difficult to apply to the facility that operates continuously for more than two hours for 24 hours, but the facility that operates for a certain time per day or the partial operation facility that operates for 24 hours a day for six days a day can be treated with the method of FIG. In addition, the scheme of FIG. 8 along with the scheme of FIG. 7 is also proposed.

The core of the method of FIG. 8 is that the adsorption process is carried out during operation and the VOC treatment is continuously possible through the desorption process during operation.The heat recovery rate is lower than that of FIG. Although it is somewhat inconvenient to operate and maintain because it needs to be detached, it is an advantage over other methods (3rd, 4th, 5th, 6th).

Hereinafter, the technical configuration for achieving the object of the present invention with reference to the accompanying drawings, Figure 8 drawings in detail as follows.

In FIG. 8, the adsorption tower exhaust fan 402 is operated while the adsorption tower inlet opening and closing damper 42 and the outlet opening and closing damper 43 are opened and the removable hot air inlet opening and closing valve 44 and the outlet opening and closing valve 45 are closed. Thus, the VOC generated during the booth operation is adsorbed and removed by the adsorption tower 4.

After the booth operation is completed, the activated carbon 41 is regenerated by desorbing the VOC adsorbed on the activated carbon during operation. In this case, the booth air supply fan 2, the exhaust fan 3, and the adsorption tower exhaust fan 402 are stopped. Close the adsorption tower inlet opening and closing damper (42) and outlet opening and closing damper (43), open and remove the hot air inlet opening and closing valve (44) and outlet opening and closing valve (45), and remove the desorption line related valves (91) and (92) in the The VOC generated during desorption by operating the hot air supply fan 6 and the catalytic combustion device 7 is burned and removed by the catalytic combustion device 7, and the activated carbon 41 in the adsorption tower 4 is generated by the high temperature exhaust gas generated at this time. It is a facility consisting of a circulation structure that desorbs.

In case of installing the device of this invention (Fig. 7 method, Fig. 8 method) to treat VOCs generated at the facilities where painting and drying are done in one place, existing methods (Fig. 3, 4, 5, Compared with Fig. 6), it is much improved in terms of economy, device size, and maintenance.

First, in terms of economic efficiency, the annual operating cost is lower than other methods because activated carbon consumption cost, which is an advantage of adsorption and desorption method, is lower, and heat recovery is performed simultaneously with dry heat recovery and desorption heat compared with other methods of FIGS. It can reduce operating cost by heat recovery.

Second, in terms of equipment costs, the two systems of FIG.

Third, in terms of maintenance and repair, the system is simpler than the method of FIG. 5, the amount of activated carbon replacement is small, and the structure is easy to replace, which is advantageous over other methods.

Fourth, the installation space of the device is also reduced to 1/2 because it is one unit compared to FIG. 5, and the size of the adsorption tower is smaller because the activated carbon is smaller than that of FIG. .

Then, in order to show how much the economic efficiency of the method of Figure 7 compared to other methods numerically based on the operating conditions Table 1 as follows.

① Equipment cost

㉮ adsorption tower body

Equipment cost per unit of Method 5: KRW 15,000,000

㉯ activated carbon value

Value equivalent to one of the 5th system: 550,000 won

㉰ Exhaust Fan and Electric Facility

5,000 won

㉱ catalytic combustion tower

Same as the way in Fig. 5: 10,000,000 won

㉲ Other: 6,000,000 won

② annual operating cost

㉮ Activated carbon consumption

Same as the way of way 5: 1,100,000 won (twice a year)

㉯ Power cost

Same as the 5th way: 600,000 won

㉰ Catalyst replacement ratio

Same as the way in Fig. 5: KRW 1,700,000

㉱ Additional fuel costs

As shown in the figure 11, the amount of heat is supplied until the initial dry exhaust gas is heated up to the temperature required for catalytic decomposition. After that, the drying and desorption heats are simultaneously recovered using VOC decomposition heat. Reduction.

Energy saving heat = drying heat ⑧ × total drying time per year

= 241 kcal / min × 300 min / day × 300 day / year

= 21,690,000 kcal

발열 When 10,000 calories are applied per 1 m3 of LNG

Energy recovery cost = 2,711 ㎥ / year × 400 won / ㎥ ≒ 1,000,000 won

㉳ other

Same as the way in Fig. 5: 500,000 won

In addition, the economic feasibility of the method of FIG. 8 applied to a painting-only facility or a facility that cannot be distinguished from the painting process is similar to that of the method of FIG. This is summarized in Table 3 below.

In conclusion, in the Tables 2 and 3, the present invention shown in FIG. 7 and FIG. 8 method is 30 ~ in economical aspect compared to other methods (3, 4, 5, 6). There is a 60% reduction, and the operating conditions are different from Table 1, which reduces paint usage and operating time, resulting in a decrease in VOC emissions or vice versa. Even if it saves at least 30% compared to the existing method. In addition to the economic feasibility, the installation space is the smallest in Tables 2 and 3, and in terms of energy recovery, it is more advantageous in terms of energy saving, simple maintenance and repair system, and convenient replacement of activated carbon. The effect of the design will be very large.

[Table 3] Comparison of Economics by Method

Claims (2)

It is a facility applied to remove volatile organic compound vapors discharged from painting facilities that alternately paint and dry in one place. It is equipped with one adsorption tower and catalytic combustion device. An air supply fan for introducing external air to adsorb and remove volatile organic compound vapors discharged during the painting operation from the adsorption tower during the painting operation; A booth exhaust fan configured to guide air introduced through the air supply fan to the adsorption tower after ventilating the paint booth; An adsorption tower exhaust fan configured to exhaust air guided by the booth exhaust fan to the stack through activated carbon of the adsorption tower; In the drying operation, the volatile organic compound vapor discharged during the drying operation is heat-exchanged with the hot air heated by the heater heat of the catalytic combustion device and the decomposition heat of the volatile organic compound generated in the catalyst layer at the previous stage, and thus contains the volatile organic compound vapor discharged during the drying operation. Heat the air to desorb and regenerate the organic compounds adsorbed on the activated carbon with the heated air, and exhaust air from the booth to remove the volatile organic compound vapor discharged from the catalytic combustion device together with the organic compound vapor discharged during the drying operation. A drying exhaust fan leading to the heat exchanger and passing through the activated carbon layer to the catalytic combustion device; Mouth to be guided to the catalytic combustion device via the air heated through the heat exchanger. Outlet valve; And A dry heat supply pipe configured to circulate the hot air into the dry heat supply pipe of the paint booth to use waste heat of the heated air after the catalytic combustion, and then exhaust it to the stack through a heat exchanger; 1 tower adsorption, characterized in that configured to include. Desorption type adsorption tower. It is applied to a facility that discharges volatile organic compound vapors that are discontinuous work such as a paint booth that stops work after a certain time of work after one day of work and is equipped with one adsorption tower and a catalytic combustion device. An air supply fan for introducing external air to adsorb and remove the volatile organic compound vapor discharged during operation in the adsorption tower; A booth exhaust fan configured to guide air introduced by the air supply fan to the adsorption tower after ventilating the booth workplace; An adsorption tower exhaust fan configured to exhaust the air guided by the booth exhaust fan to the stack through the coal briquettes of the adsorption tower; A desorption hot fan for putting hot air heated by the heat of the catalytic combustion device and the heat of decomposition of the volatile organic compounds generated in the catalyst layer to desorption and regenerate the organic compound adsorbed to the active adsorption tower during operation; A desorption hot air is sent through the adsorption tower activated carbon bed to the catalytic combustion device. Outlet valve; And Desorption hot air pipe installed so that the desorption hot air flows; 1 tower adsorption, characterized in that configured to include. Desorption type adsorption tower.