Hot Air Desorption Type Adsorption Tower with Condensing Water Absorber

Abstract

The present invention relates to a volatile organic compound (VOC) removal device, wherein Activated carbon adsorption towers are currently widely used devices for removing volatile organic compounds (VOCs) contained in exhaust gases. However, activated carbon adsorption towers have the problem of incurring excessive activated carbon replacement costs due to the characteristic that they become saturated and can no longer adsorb once a certain amount of adsorbent is adsorbed. To address this problem, the industrial sector has used a method of applying steam heat to desorb and regenerate the adsorbed material when the activated carbon reaches a saturated state. However, this method requires separate utilities such as steam, and the equipment costs are high due to the use of expensive materials such as stainless steel caused by corrosion from moisture. Furthermore, it has several problems, such as the generation of a large amount of residual moisture in the activated carbon after desorption, so it is rarely used in recent years. As an alternative, a desorption and regeneration method using hot air heating instead of steam heat has been adopted. Initially, the hot air heating desorption regeneration method of Fig. 3 was developed and used, but it was found that there were problems with excessive power costs and that the desorption regeneration time was long when actually used, and also that there were problems with fires of unknown cause occurring occasionally. Accordingly, the present invention aims to solve such problems. The following solutions were applied. The problem of excessive power costs was resolved by applying a method that recovers and utilizes the heat contained in the exhaust gas of the catalytic cracking device for desorption heat, and a method that enables an optimized amount of desorption exhaust gas. The problem of the long detachment and regeneration time was solved by increasing the detachment performance, and as a solution, a method was applied to increase the detachment airflow without increasing power costs. Upon tracing the cause of the occasional fires, it was discovered that they occur due to the reaction heat generated when ketones, such as methyl ethyl ketone, react with activated carbon during heating for desorption. As a solution, a steam condensate film absorption device was installed upstream of the adsorption tower to remove fire-causing substances like methyl ethyl ketone. Furthermore, to ensure automatic fire suppression even after the removal of these substances, a fire safety device was installed that sprays water onto the activated carbon when its temperature rises above a certain level. The present invention aims to provide a hot air desorption regenerative type adsorption tower equipped with a condensate film absorption device according to the method of Fig. 4 to which the solution is applied. [Keywords] VOC removal device, hot air desorption regenerative adsorption tower,

Description

Technology Field

[0001] The present invention relates to a volatile organic compound (VOC) removal device. Background Technology

[0002] Organic compound solutions are used as solvents and cleaning agents in various facilities such as painting facilities, printing facilities, and washing facilities. During this process, large amounts of volatile organic compound (VOC) vapors, such as toluene, xylene, and methyl ethyl ketone, are released into the atmosphere, causing air pollution, and thus it is necessary to remove them.

[0003] Devices currently widely used as volatile organic compound (VOC) removal devices include

[0004] The activated carbon adsorption tower shown in Fig. 1 is used because the technology is widely available, the structure is simple, and the installation cost is low.

[0005] However, as shown in Fig. 2, the activated carbon adsorption tower has the problem of incurring excessive activated carbon replacement costs due to the characteristic that it becomes saturated (C4 state) and can no longer adsorb VOCs once a certain amount is adsorbed.

[0006] For example, if you calculate the annual cost of replacing activated carbon...

[0007] When exhaust gas volume is 300 m³ / min @ 0℃ and methyl ethyl ketone (MEK) is emitted at 300 ppm (ml / Nm³)

[0008] Methyl ethyl ketone discharge = 300 m³ / min x 300 ml / m³ x (72.1 mg / 22.4 ml) x 10 -6 kg / mg x 60 = 5.4kg-MEK / hr

[0009] Methyl ethyl ketone (MEK) adsorption capacity per 1 kg of activated carbon = Max 0.3 kg - MFK / kg - activated carbon

[0010] Therefore, activated carbon consumption

[0011] = (5.4kg-MEK / hr) / (0.3kg-MFK / kg-activated carbon) = 18kg-activated carbon / hr

[0012] If discharged for 8 hours a day for 300 days a year

[0013] Annual activated carbon consumption = 18 kg - activated carbon / hr x 8 hr / day x 300 days / year = 43,200 kg / year

[0014] Annual activated carbon replacement cost = 43,200 kg / year x minimum 3,000 won / kg - activated carbon = approximately 130 million won

[0015] As such, the problem of excessive activated carbon consumption in activated carbon adsorption towers must be resolved, and as a solution to this problem, recently,

[0016] As shown in Fig. 3, the problem of excessive activated carbon consumption has been solved by adopting a method of desorbing and regenerating the adsorbed VOCs by applying steam heat to the activated carbon saturated with activated carbon, thereby repeatedly reusing the activated carbon by desorbing and regenerating it to the C1 state when it is saturated in the C4 state.

[0017] However, this method is rarely used these days due to various problems, such as the need for separate utilities like steam, high equipment costs resulting from the use of expensive materials like stainless steel due to corrosion caused by steam condensation on the activated carbon, and the requirement to dry the large amount of moisture remaining on the activated carbon after desorption.

[0018] For reference, activated carbon is rarely used due to issues such as the formation of a water film on its surface if condensed water is present, which blocks the micropores and causes a loss of adsorption capacity, thus requiring drying. The problem to be solved

[0019] The present invention aims to solve the problem of excessive activated carbon consumption in a general adsorption tower (Fig. 1) by using an adsorption method that involves desorption and regeneration, but instead of using a method using steam heat which is problematic, it applies a method of desorption and regeneration using hot air heat.

[0020] The method of desorption and regeneration using hot air is as shown in Fig. 3, and the specific processing method is as follows.

[0021] The basic treatment method is a process of adsorption during operation and desorption regeneration during idle operation. During operation, the adsorption process is performed with the inlet opening / closing damper (102) and the outlet opening / closing damper (103) open, and VOC-containing exhaust gas passes through the activated carbon (101) to be adsorbed and removed, and then discharged into the atmosphere. When the activated carbon reaches a saturated state due to continuous adsorption, the desorption regeneration process during idle operation (usually at night or on weekends) is performed with the inlet opening / closing damper (102) and the outlet opening / closing damper (103) closed, and hot air generated by the hot air supply fan (3) and the heater (301) is applied to the activated carbon to desorb the adsorbed VOC. The high concentration of VOC that is desorbed flows into the catalytic combustion device (4), is heated to a catalytic decomposition temperature (250~350℃) by the heater (403), and then decomposed into CO2 and H2O by an oxidation catalyst (usually a platinum catalyst) and discharged into the atmosphere.

[0022]

[0023] However, when applying the basic hot air detachment method as shown in Fig. 3, it has the following three problems.

[0024] 1. The first problem concerns activated carbon fires during desorption regeneration. When ketones such as methyl ethyl ketone are present in the exhaust gas, there is a problem where a fire occurs due to the reaction heat generated when the adsorbed ketones react with the activated carbon due to the heat of desorption during desorption regeneration.

[0025] 2. The second problem concerns excessive operating costs due to high power costs; for example, if we calculate the power costs using the method in Fig. 3,

[0026] When the exhaust fan (2) airflow is 300 m³ / min and the desorption hot airflow (hot air supply fan airflow) is 30 m³ / min, which is 10% of the exhaust fan airflow.

[0027] (1) When calculating the power of the hot air heater (301)

[0028] When heating the desorption hot air temperature to 100℃

[0029] H = m Cp △t

[0030] Hot air flow rate m = 30 m³ / min x 1.2 kg / m³ @ 20℃ = 36 kg / min

[0031] Specific heat of air at constant pressure = Cp = 0.23 kcal / kg-℃

[0032] Heating temperature difference △t = (100℃-20℃) = 80℃

[0033] Therefore, H = 36 kg / min x 0.23 x 80℃ = 662.4 kcal / min = approximately 50 kW

[0034] (2) When calculating the power of the catalytic device heater (403)

[0035] When heating to 300°C to catalytically decompose the VOCs that are desorbed, the power of the catalytic device heater (403) is

[0036] H = 36 kg / min x 0.23 x (300℃ - 100℃) = 1656 kcal / min = approx. 110 kW

[0037] Therefore, it can be seen that high heater power is required, with total heater power = 50kw + 110kw = 160kw.

[0038] 3. The third problem concerns the long re-attachment time due to limited attachment / detachment performance.

[0039] The desorption performance of adsorbed VOCs is proportional to the amount of desorption heat applied to the activated carbon, and the amount of desorption heat is proportional to the desorption hot air temperature and the desorption hot air flow rate.

[0040] Here, regarding the desorption hot air temperature, if heated to 180°C or higher, the activated carbon oxidizes rapidly and ignites, leading to a fire. Therefore, for safety reasons, there is a limiting condition that the temperature must be heated to 150°C or lower. Regarding the desorption hot air flow rate, as the flow rate increases, the power of the hot air heater (301) and the catalytic combustion device heater (403) must be increased, and the catalytic combustion device (4) also becomes larger, which causes problems such as increased power costs and equipment costs. Therefore, the desorption hot air flow rate is also generally limited to 10% or less of the exhaust fan (2) air volume.

[0041] In conclusion, the limited hot air temperature and desorption hot air flow rate result in low desorption performance, which requires a long desorption time and causes various problems in actual operation. (See Fig. 8)

[0042] The main problem to be solved by the present invention is the solution of the three problems mentioned above.

[0043] 1. Solution to the first problem, the activated carbon fire issue

[0044] a. Use of non-flammable adsorbents such as zeolites

[0045] Generally, activated carbon is widely used as an adsorbent because it is relatively inexpensive; however, as described above, the desorption and regeneration method involving the application of heat, as in the present invention, has a problem of being vulnerable to activated carbon fire.

[0046] Therefore, the use of zeolite, a non-flammable adsorbent that does not cause fires, can be considered.

[0047] However, natural zeolites extracted from mines or general-purpose zeolites used in detergents are highly hydrophilic materials; therefore, if used, they first adsorb water vapor contained in exhaust gases, making them unable to adsorb VOCs and thus unsuitable for use.

[0048] Accordingly, it is possible to use a general-purpose zeolite by changing its hydrophilicity to hydrophobicity through various modification processes such as dialumina, but since the modification process requires advanced technology and there is almost no demand, there is no domestic production, and although there are some imported products, they are expensive, costing tens of times more than activated carbon, so they are excluded from consideration in this invention.

[0049] B. Installation of removal devices for fire-causing substances such as methyl ethyl ketone and fire safety devices

[0050] 1) Installation of fire-causing substance removal devices

[0051] Taking into account that ketones such as methyl ethyl ketone are water-soluble substances, a device that absorbs and removes them with water is installed as a fire-causing substance removal device to prevent fire.

[0052] As for the absorption device serving as a removal device for fire-causing substances, instead of the widely used packed tower type absorption device, the absorption device is installed on the condensation film generated by cooling and condensing the water vapor contained in the exhaust gas; the reason and detailed contents thereof are to be described in the specific details for implementing the invention.

[0053] 2) Installation of fire safety devices

[0054] The reason for installing additional fire safety devices despite the installation of fire-causing substance removal devices is to prevent fires caused by unknown factors, such as problems with the removal devices.

[0055] The fire safety device (6) is configured to prevent fire by installing a temperature sensor and a temperature controller in the activated carbon layer as shown in FIG. 4, and when the set temperature of the temperature controller reaches a fire hazard temperature (e.g., 180°C) due to the reaction heat of ketones, opening the water pipe Solenoid Valve (601) installed in the activated carbon layer to spray water onto the activated carbon layer (101) for a certain period of time to lower the temperature of the activated carbon layer.

[0056] For reference, while it is possible to consider installing only a fire safety device without a fire-causing substance removal device, if the concentration of fire-causing substances is high, the reaction heat of a large amount of such substances can cause a rapid rise in temperature; in this case, a fire may occur even if the fire safety device is activated.

[0057] Accordingly, the present invention adopts a method of installing both a fire-causing substance removal device and a fire safety device.

[0058] In addition, the fire-causing substance removal device can remove other water-soluble substances, such as alcohols, along with fire-causing substances, thereby reducing the amount of activated carbon. This also yields the secondary effect of increasing economic efficiency by reducing the capacity of the desorption and regeneration device.

[0059] 2. Solution to the second problem: excessive operating costs caused by high heater power

[0060] 1) Use recovered waste heat to replace the heat required for detachment.

[0061] Power costs are reduced by supplying desorption heat without a separate heating device by recovering the high-temperature gas heat (waste heat) discharged after desorption VOC catalytic decomposition and using it as desorption heat for the heat required for VOC desorption (desorption hot air heat). (A method without a separate hot air heater (301) is applied)

[0062] 2) Introduction of a device capable of optimized desorption exhaust gas volume

[0063] By minimizing the amount of desorption exhaust gas with an optimized amount of desorption exhaust gas, the amount of heat used for catalytic decomposition is reduced, thereby reducing power costs (reducing power costs by lowering the capacity of the catalytic device heater (403)).

[0064] 3. Solution to the third problem, the issue caused by limited detachment performance

[0065] Methods to improve desorption performance require raising the desorption temperature or increasing the volume of hot air for desorption, but the desorption temperature is limited to 180℃ or lower due to fire hazards.

[0066] It has been stated that the amount of hot air for removal is limited to 10% or less of the exhaust fan airflow due to economic issues, and consequently, problems caused by limited removal performance are inevitable.

[0067] Therefore, in the present invention, a method to increase the amount of air to remove without increasing power costs was sought by applying the second problem-solving method above, and as a result, this problem was solved by adopting the method shown in Fig. 4.

[0068] That is, in the case of detachment regeneration in FIG. 4, the exhaust gas discharge blocking damper (103) is closed and the detachment hot air blocking damper (401) is opened to heat with the maximum amount of detachment hot air equal to the airflow of the exhaust fan (2), thereby dramatically increasing the detachment performance compared to the method in FIG. 3 and solving the problem of the long detachment time required. (See FIG. 8)

[0069] Further detailed and additional explanations are to be described in the "Specific Details for Implementing the Invention" set forth below. means of solving the problem

[0070] As the problems of the conventional method and solutions have been presented so far, in order to complete the task to be solved, the present invention introduces a method such as that shown in Fig. 4, and intends to solve the task by installing the following device in Fig. 4.

[0071] An adsorption device equipped with an adsorption tower (1) filled with activated carbon (101) and an exhaust fan (2) for exhausting exhaust gas, which is a device for adsorbing and removing volatile organic compounds emitted during operation in Fig. 4.

[0072] A device for desorbing and regenerating adsorbed activated carbon during downtime

[0073] An inlet opening / closing damper (102) that opens when adsorbing and closes when desorbing / regenerating at the inlet of the adsorption tower

[0074] A device for heating to desorb and regenerate volatile organic compounds adsorbed on activated carbon during idle operation, a desorption hot air duct (401) through which desorption hot air moves, a desorption hot air opening / closing damper (4011) that closes upon adsorption and opens upon desorption, and conversely, an outlet opening / closing damper (1041) that opens upon adsorption and closes upon desorption.

[0075] A device that catalytically decomposes volatile organic compounds that are desorbed into harmless carbon dioxide and water vapor, and a catalytic device heater (403) that heats the desorbed volatile organic compounds to the catalytic decomposition temperature set in the catalytic decomposition temperature controller.

[0076] A catalytic decomposition device (4) equipped with a catalyst (404) (typically a platinum catalyst) that decomposes volatile organic compounds,

[0077] A desorption hot air heating gas duct (405) that supplies desorption heat and introduces high-temperature exhaust gas discharged from a catalytic decomposition device, and a desorption hot air heating gas control damper (4051) that heats the desorption hot air to the desorption hot air temperature set by a desorption hot air temperature controller.

[0078] A device that discharges the minimum amount of desorption exhaust gas while ensuring explosion safety, comprising a desorption exhaust gas duct (402) and a desorption exhaust gas amount control damper (4021) that controls the amount of desorption exhaust gas based on the set temperature after catalytic decomposition by a temperature controller after catalytic decomposition.

[0079] To prevent activated carbon fires, a heat transfer plate (501) composed of many thin plates that form a condensation film as a fire-causing substance removal device is installed upstream of the adsorption tower (1).

[0080] A refrigerant pipe (502) installed on a heat transfer plate so that the heat transfer plate is cooled by the heat of vaporization of the refrigerant,

[0081] A water vapor condensation film absorption device that connects an outdoor unit (503), which is a device for liquefying vaporized refrigerant to enable continuous cooling, and a refrigerant compressor (504).

[0082] A hot air desorption regenerative adsorption tower equipped with a condensate film absorption device, characterized by being composed of a device having a water pipe (6) for supplying firefighting water to activated carbon as a fire safety device, and a firefighting water supply shut-off valve 601) that is opened by an activated carbon temperature controller to spray water onto the activated carbon when the activated carbon temperature reaches a fire-inducing temperature. Effects of the invention

[0083] The effect of the present invention as shown in the manner of Fig. 4 is

[0084] First, it effectively solves the problem of excessive activated carbon consumption caused by replacing activated carbon whenever it becomes saturated in conventional adsorption towers by performing desorption regeneration whenever the activated carbon becomes saturated.

[0085] Secondly, by introducing a hot air heat desorption regeneration method instead of the steam heat desorption regeneration method (method in Fig. 2), which has poor economic feasibility and issues with activated carbon moisture generation, it is possible to improve economic feasibility and install a desorption regeneration adsorption tower that does not generate activated carbon moisture.

[0086] Third, the basic hot air desorption regeneration adsorption tower of Fig. 3 has problems such as the fire of activated carbon during desorption regeneration when ketones such as methyl ethyl ketone are adsorbed by activated carbon, excessive power costs required for desorption regeneration, unstable desorption due to low desorption performance, and long desorption regeneration time, but the hot air desorption regeneration type adsorption tower equipped with a condensate film absorption device of Fig. 4 has the effect of solving these problems. Brief explanation of the drawing

[0087] Figure 1 is an adsorption tower flowchart Figure 2 is a flowchart of a steam desorption regeneration type adsorption tower. Figure 3 is a flowchart of a basic hot air desorption-regeneration type adsorption tower. Figure 4 is a flowchart of a hot air desorption-regenerating adsorption tower equipped with a condensate film absorption device. Figure 5 is a flowchart of a packed tower type absorption device. Figure 6 is the adsorption characteristics of the activated carbon adsorption tower. Figure 7 is a conceptual diagram of the absorption device. Figure 8 is the desorption VOC concentration curve of the methods in Figure 3 and Figure 4. * Explanation of symbols for major parts of the drawing 1 ....... Adsorption tower 2 ....... Exhaust fan 101 ...... Activated carbon 102.... Inlet opening / closing damper 103....... Outlet opening / closing damper 104.... Discharge port 1041....... exhaust opening / closing damper 3......... hot air supply fan 301 ...... Hot air heater 4..... Catalytic decomposition device 401 .........Removable hot air duct 4011 ..... Removable hot air opening / closing damper 402 ........ Detachment exhaust gas duct 4021 ..... Detachment exhaust gas volume control damper 403 ...... Catalytic converter heater 404 ..... Catalytic converter 405 ......Desorption hot air heating gas duct 4051 .....Desorption hot air heating gas control damper 5 ......... Condensation film type absorption device 501 ....... Heat transfer plate 502 ...... Refrigerant pipe 503 ....... Outdoor unit 5031 ..... Cooling fan for outdoor unit 504 ....... Refrigerant compressor 6 ...... Water piping for fire water supply 601 ....... Fire water supply shut-off valve 7 ........ Packed tower type absorption device 701 ....... Packing material 702 ..... Absorbent liquid supply pump Specific details for implementing the invention

[0088] The additional explanation regarding the solution to the problem and the functions and roles of the device in the task to be solved is as follows.

[0089] 1. Additional explanation regarding solutions to the problem

[0090] A. Explanation of the absorption device for removing fire-causing substances among the solutions to the first problem, activated carbon fires during desorption and regeneration

[0091] The reason the steam condensation film method was adopted as the absorption device for removing fire-causing substances in this invention is that continuous removal is possible even with a small amount of wastewater, whereas packed tower type absorption devices have the problem of generating a large amount of wastewater.

[0092] To explain this in detail, the structure of the packed tower type absorption device is as shown in FIG. 5. The absorption process involves a flow in which exhaust gas containing ketones (hereinafter referred to as "absorbent material"), such as methyl ethyl ketone, which are substances to be absorbed and removed, passes through a layer of packing material (102) and is discharged into the atmosphere. During this process, the absorbent material is absorbed into the absorbent liquid (usually water) in the layer of packing material (701), and the absorbed water falls down to the bottom of the packed tower and is then circulated to the pump (502) to absorb and remove it.

[0093] Here, the absorption principle in the packing layer of the packed tower type absorption device is that absorption occurs through mass transfer caused by the difference in concentration of the absorbent substance in the exhaust gas and the absorbent substance in the absorbent liquid in the water film formed on the surface of the packing, as shown in Fig. 7.

[0094] Therefore, the absorption and removal performance of a packed tower is proportional to the transport speed of the absorbed substance, which is proportional to the concentration difference.

[0095] However, as shown in Fig. 7, initially, the concentration of the absorbent substance in the absorbent solution is very low, so the concentration difference is large and the absorption efficiency is high. Subsequently, as absorption continues through circulation, the concentration of the absorbent substance in the absorbent solution gradually increases, causing the concentration difference to decrease until it reaches the gas-liquid equilibrium concentration, at which point no absorption occurs.

[0096] Therefore, to maintain continuous absorption performance, the concentration of the absorbent substance in the absorption solution must not increase, and a method is used to continuously remove the absorbed substance using chemicals or the like.

[0097] For example, if the absorbent substance is an acid gas (hydrogen sulfide, methyl mercaptan, etc.), it is removed by adding a chemical such as a caustic soda solution, and if it is a basic substance such as trimethylamine or ammonia, a method is used to remove it by adding a chemical such as sulfuric acid.

[0098] However, in the case of ketones such as methyl ethyl ketone, it is difficult to apply methods of removal using chemicals, such as neutralization removal like with acids and basic gases.

[0099] In other words, since removing organic compounds absorbed into the absorption solution requires separate wastewater treatment devices, such as microbial treatment, it incurs enormous costs, making it difficult to apply packed tower absorption systems.

[0100] Accordingly, in this invention, as shown in FIG. 4, a method is adopted in which water vapor contained in the exhaust gas is absorbed and removed by a large-area condensate film generated by cooling and condensing it at the front of the activated carbon adsorption tower. Since only a small amount of discharged condensate is generated as wastewater, continuous removal is possible with minimal wastewater generation, and this method was applied.

[0101] B. Explanation of solutions for the second problem, excessive power costs

[0102] 1) Regarding the recovery and use of desorption heat required for desorption

[0103] The recovery of desorption heat is achieved through the following process.

[0104] The heat required for desorption (hereinafter referred to as "desorption heat") is the sum of the heat required to heat the adsorbed activated carbon to the temperature at which desorption occurs (typically 80 to 120°C), the heat of vaporization of the adsorbed VOC, and the heat loss generated during the desorption process. By heating a portion of the high-temperature exhaust gas of 300 to 500°C through the desorption heating gas duct (405) and the desorption hot air duct (401) to the activated carbon, the heat consumed as desorption heat is replenished.

[0105] The amount of high-temperature heating gas to be replenished is automatically controlled by the control damper (4051) based on the temperature signal set in the desorption hot air temperature controller.

[0106] 2) Regarding the selection of an appropriate desorption exhaust gas volume

[0107] In FIG. 4, to catalytically decompose the desorbed VOC contained in the desorbed exhaust gas, the catalytic decomposition temperature is heated to 250~350℃, and since the heating heat of the catalytic device heater (403) is proportional to the amount of desorbed exhaust gas, it not only has a direct effect on the power cost

[0108] Since this corresponds to the processing capacity of the catalytic decomposition device (4) and is directly related to the equipment cost of the catalytic decomposition device, it is important to select an appropriate amount of desorption exhaust gas. In other words, the smaller the amount of desorption exhaust gas, the more advantageous it is in terms of power and equipment costs, but if it is too small, there is a possibility of explosion due to the accumulation of desorption VOCs.

[0109] Accordingly, the amount of desorption exhaust gas is selected to maintain the concentration of desorption VOCs at 1 / 10 or less of the lower explosive limit concentration. Since the lower explosive limit concentration is typically tens of thousands of ppm, a safety factor of 10 times is applied to the concentration of desorption VOCs, so a minimum concentration of around 1,000 ppm, which is 1 / 10 or less of the lower explosive limit concentration, is desirable.

[0110] The device is designed to operate with a minimum amount of desorption exhaust gas while maintaining the desorption VOC concentration, utilizing the temperature difference between before and after catalytic decomposition caused by the decomposition heat of the desorption VOC. That is, since the temperature rise after catalytic decomposition due to decomposition heat is approximately 1°C per 10 ppm of desorption VOC concentration, the device is configured to discharge an amount of desorption exhaust gas that maintains a temperature difference of about 100°C between before and after catalytic decomposition. The device is configured so that the amount of desorption exhaust gas is automatically controlled by a desorption exhaust gas volume control damper (4021) based on a temperature signal set in the post-catalytic temperature controller.

[0111] C. Explanation of the application of a large-capacity detachment airflow to maximize detachment performance, proposed as a solution to the problem of limited detachment performance.

[0112] Regarding the problem to be solved above, the cause of the limited detachment performance is the limited detachment airflow due to power cost issues, and a solution to increase the detachment airflow without increasing power costs has been proposed.

[0113] The reason for the increased detachment airflow is

[0114] This is because the issue of power costs associated with increased desorption airflow has been resolved by minimizing the heat required for desorption through a circulation structure and simultaneously recovering and utilizing the minimized desorption heat as waste heat. As this makes it possible to increase the desorption airflow, the maximum desorption airflow has been applied, taking into account that desorption performance and stability increase as the airflow increases.

[0115] Figure 8 presents the desorption concentration characteristics (laboratory test) of the conventional method (Figure 3) and the method of the present invention (Figure 4). It can be seen that the desorption performance and stability of the method in Figure 4 are significantly improved compared to the method in Figure 3.

[0116] Here, as a device to enable the application of the maximum desorption airflow, the exhaust gas discharge blocking damper (103) is closed and the desorption hot air blocking damper (401) is opened during desorption regeneration in FIG. 4, so that desorption is circulated with the maximum desorption hot airflow equal to the airflow of the exhaust fan (2).

[0117] 2. Additional explanation of the device's functions and roles

[0118] In describing the embodiments of the device presented in the present invention, regarding the description of the device's configuration, function, operation, etc., if several features requiring understanding are explained separately, in the manner of Fig. 4

[0119] 1) Activated carbon fire prevention device upon detachment

[0120] a) Fire-causing substance removal device

[0121] A water vapor condensation film type absorption device (5) equipped with a heat transfer plate (501) composed of several thin plates that form a condensation film by cooling of water vapor at the front of an adsorption tower (1) as a fire-causing substance removal device, a refrigerant pipe (502) installed on the heat transfer plate so that the heat transfer plate is cooled by the heat of vaporization of the refrigerant, and a water vapor condensation film type absorption device that connects an outdoor unit (503), which is a device for liquefying the vaporized refrigerant to enable continuous cooling, and a refrigerant compressor (504).

[0122] b) Fire safety device

[0123] A device equipped with a fire-causing substance removal device, which can prevent fires, but is a safety device that sprays water onto the activated carbon when the activated carbon temperature rises above the fire hazard temperature (e.g., 180℃) due to unexpected variables, and a water pipe (6) that supplies firefighting water to the activated carbon and a firefighting water supply shut-off valve 601) that opens the water pipe to spray firefighting water onto the activated carbon layer by means of an activated carbon temperature controller.

[0124] 2) Activated carbon desorption and regeneration device

[0125] Activated carbon desorption regeneration takes place during downtime after adsorption on the activated carbon during operation.

[0126] Desorption and regeneration devices can be broadly divided into an activated carbon heating device that heats activated carbon for desorption and a catalytic decomposition device that decomposes VOCs desorbed by heating into CO2 and H2O.

[0127] a) Activated carbon heating device

[0128] A desorption hot air device that heats to desorb and regenerate volatile organic compounds adsorbed on activated carbon during idle operation, a desorption hot air duct (401) that supplies desorption hot air through an exhaust fan (2), a desorption hot air opening / closing damper (4011) that closes when adsorbed and opens when desorbed, and conversely, an outlet opening / closing damper (1031) that opens when adsorbed and closes when desorbed.

[0129] The device that supplies desorption heat using the high-temperature exhaust gas heat of the catalytic device consists of a high-temperature hot air duct (405) that supplies the high-temperature exhaust gas discharged from the catalytic decomposition device as desorption hot air, and a high-temperature heating flow rate control damper (4051) that heats the desorption hot air to the desorption hot air temperature set by the desorption hot air temperature controller.

[0130] b) Catalytic decomposition device

[0131] A device that catalytically decomposes volatile organic compounds into harmless carbon dioxide and water vapor, and a catalytic device heater (403) that heats the decomposed organic compounds to the catalytic decomposition temperature set in the temperature controller.

[0132] It consists of a catalytic decomposition device (4) equipped with a catalyst (404) (typically a platinum catalyst) that decomposes volatile organic compounds.

[0133] c) Desorption exhaust gas volume control device

[0134] The device is configured to maintain a minimum discharge amount while preventing explosion of the adsorption tower (1) and the catalytic decomposition device (4), and consists of a desorption exhaust gas duct (402) and a desorption exhaust gas amount control damper (4021) that controls the amount of desorption exhaust gas by controlling the amount of desorption exhaust gas according to the temperature after catalytic decomposition set by the catalytic decomposition temperature controller.

Claims

Claim 1 In FIG. 4, an adsorption device equipped with an adsorption tower (1) filled with activated carbon (101) and an exhaust fan (2) for exhausting exhaust gas, which adsorbs and removes volatile organic compounds emitted during operation; an inlet opening / closing damper (102) at the inlet of the adsorption tower that opens upon adsorption and closes upon desorption / regeneration, which is a device for desorbing and regenerating the adsorbed activated carbon during idle operation; a desorption hot air duct (401) through which desorption hot air moves, which is a device for heating to desorb and regenerate the volatile organic compounds adsorbed on the activated carbon during idle operation, which closes upon adsorption and opens upon desorption, and a desorption hot air opening / closing damper (4011) that closes upon adsorption and opens upon desorption, and conversely, an outlet opening / closing damper (1041) that opens upon adsorption and closes upon desorption; and a device for catalytically decomposing the desorbed volatile organic compounds into harmless carbon dioxide and water vapor, which heats the desorbed volatile organic compounds to a catalytic decomposition temperature set in a catalytic decomposition temperature controller. A catalytic decomposition device (4) equipped with a catalytic device heater (403) and a catalyst (404) (typically a platinum catalyst) that decomposes volatile organic compounds; a desorption hot air heating gas duct (405) that supplies desorption heat and introduces high-temperature exhaust gas discharged from the catalytic decomposition device; a desorption hot air heating gas control damper (4051) that heats the desorption hot air to the desorption hot air temperature set by a desorption hot air temperature controller; a desorption exhaust gas duct (402) that discharges the minimum amount of desorption exhaust gas while ensuring explosion safety and a desorption exhaust gas volume control damper (4021) that controls the amount of desorption exhaust gas by the desorption exhaust gas volume set by a catalytic decomposition post-temperature controller; a heat transfer plate (501) composed of many thin plates that form a condensate film as a fire-causing substance removal device at the front of the adsorption tower (1) to prevent activated carbon fire; and a device installed on the heat transfer plate to cool the heat transfer plate by the heat of vaporization of the refrigerant. A refrigerant pipe (502), a water vapor condensation film absorption device that connects an outdoor unit (503) and a refrigerant compressor (504) which are devices for liquefying vaporized refrigerant to enable continuous cooling, and a water pipe (6) for supplying fire extinguishing water to activated carbon as a fire safety device,A hot air desorption regenerative adsorption tower equipped with a condensate film absorption device, characterized by being composed of a device having a fire water supply shut-off valve 601) that is opened by an activated carbon temperature controller to spray water onto the activated carbon when the activated carbon temperature reaches a fire-inducing temperature.

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