KR200385826Y1 - Circulation & Fire Safety Type Catalistic Cleaning Desorber - Google Patents

Abstract

The present invention is an apparatus applied to a facility for desorption and regeneration of activated carbon in the activated carbon adsorption tower.

Adsorption towers (Fig. 1), which have been mainly used in the past, have been widely used as VOC removal facilities because of their simple structure and low equipment cost, but there is a problem that excessive activated carbon replacement cost is required due to the characteristics of activated carbon adsorption. Installation has solved the problem. The desorption method that has been generally used has been used to desorption and condensation by applying steam heat (Fig. 2), but the desorption device itself is expensive and the equipment cost is high due to the use of corrosion resistant materials by using steam. There was a need for a separate utility such as cooling water.

In recent years, by applying a catalytic combustion system, a desorption hot fan, a catalytic combustion device, and a heat exchanger are installed, and the hot air is exchanged by heat exchanged by a heater mounted on the catalytic combustion device to generate and remove hot air. Injecting into the catalytic combustion device was used to discharge to the atmosphere after the catalytic combustion decomposition (FIG. 3 method).

However, this method has the disadvantage that the heat recovery is less than 50% due to the heat recovery by the indirect heat exchange method by the heat exchanger, and the initial low hot air temperature must be raised above 250 ° C., which is necessary for catalytic decomposition. The capacity has to be large and a heat exchanger 8 or the like is required, resulting in an increase in equipment cost.

So, in order to solve the drawbacks of the method of FIG. 3, by adopting a circulating method using direct hot air discharged after catalytic decomposition as a desorption hot air, the heat recovery rate is increased by 80-90% or more, and the catalyst bed inlet temperature control method is not used as a heater calorific value. By reducing the heater capacity by controlling the removable hot air flow rate has led to the development of the Figure 4 method to reduce the equipment cost and operating costs.

However, this method has a fatal problem with a high risk of fire due to the continuous hot air temperature is increased to 250-450 ℃.

Therefore, the present invention adopts the basic method of FIG. 4 but uses a desorption hot fan of twice the capacity of the removable hot fan used in FIG. 4 in order to devise a fire-safe method while maintaining the advantages of the method of FIG. 4. After dividing the heater into primary and secondary heaters, 70% of the primary heating air at about 100 ° C. heated at the primary heater and the remaining 30% were reheated to 250 ° C., which is catalytically decomposable temperature, and passed through the catalyst. After the catalytic decomposition, a part of the catalyzed high temperature hot air at 250-450 ° C. is discharged to the outside, and the rest is mixed with the air heated in the primary heater through a hot air purification pipe to enter the adsorption tower to 145-205 ° C. By doing so, the fire hazard was fundamentally prevented.

Description

Circulation & Fire Safety Type Catalistic Cleaning Desorber

Many facilities, such as painting, printing, and washing facilities, use polymer organic compounds, and in the process, they contain a large amount of high molecular volatile organic compounds (VOCs) such as toluene and xylene. Emissions in the air cause air pollution.

In order to prevent air pollution caused by VOCs, various types of purification facilities are used, but most of them use activated carbon adsorption.

Until now, VOC removal technology using activated carbon adsorption method has been developed to improve the disadvantages of the method used in the past, and some of them are described as follows. Before describing each method, briefly describe the activated carbon adsorption method and catalytic combustion method, which are the basic technologies of the present method.

1) Activated carbon adsorption method

Activated carbon has many micropores and large surface area. When VOCs with high molecular weight such as benzene, toluene and xylene gas pass through activated carbon layer, organic gas molecules are introduced into the micropores by van der Waals forces, and the pressure is very high in the micropores. It is easily supersaturated, so it is adsorbed on the surface of micropores in a condensed state. 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 is performed by applying hot air or steam of 100 ° C. or higher because the activated carbon micropores are restored to their original state by the evaporation and desorption of VOC adsorbed on the surface of the activated carbon in the liquid phase.

2) Catalytic Combustion Method

The catalyst is composed of platinum, palladium, etc. It does not directly participate in the reaction, but it lowers the activation energy of the reactants to promote the reaction, so it is burned at 250 ~ 350 ℃, much lower than the combustion oxidation temperature of VOC 600 ~ 800 ℃ It is a substance that enables oxidation and saves energy. Catalytic combustion is a method using such a catalyst is heated to 250 ~ 350 ℃ capable of combustion decomposition by passing through the catalyst bed to remove the combustion by the reaction scheme is as follows.

As shown in the above reaction, when decomposing VOC in the catalyst layer, the gas temperature is increased by self-heating oxidation and the degree of increase is proportional to the VOC concentration.In case of the catalyst bed inlet temperature of 250 ℃ and VOC concentration of about 2000ppm, the hot air temperature after catalytic decomposition is about 400 ℃. To rise. This is because VOC self-decomposition heat passes through the catalyst bed, and the decomposition efficiency becomes higher due to the increase in gas temperature, so that high efficiency treatment of more than 99% is possible.

Then, each method that has been used so far for the activated carbon adsorption method is described as follows.

1) Non-removable adsorption tower (Fig. 1 method)

As shown in FIG. 1, the activated carbon 101 is charged into a simple container in the simplest manner, and then the VOC is passed through the adsorption to remove the adsorption.

However, this method has the following big problem

Since it is a simple device without a desorption and regeneration device, activated carbon must be replaced when saturated by continuous adsorption of VOC, so there is an excessive problem of replacing activated carbon.

For example, in a facility where about 2000kg of organic solvent is used and evaporates a year, the activated carbon amount is about 10000kg and the replacement cost is about 15,000,000 won.

2) Steam heat desorption and desorption VOC's cooling condensation type desorption device

This method is a method that has been used until recently as a device for regenerating activated carbon by installing a desorption device in a way to improve the problem of the method of FIG. The operation of the desorption apparatus of the present method is performed during operation. The desorption and regeneration of the activated carbon 101 using steam heat is performed after condensation of the VOC and steam discharged after desorption in the condenser 4 and the solvent condensed in the oil / water separation tank 5. It is separated by water and treated.

This will be described in detail as follows.

The system is configured as shown in FIG. 2 to close the adsorption tower inlet damper 102 and the outlet damper 103 and open the inlet steam open / close valve 104 and the outlet steam open / close valve 105 in a state where the exhaust fan 2 is stopped. When steam of 140 ~ 180 ℃ is blown, heat is applied to the VOC adsorbed on the activated carbon. As a result, the adsorbed VOC is evaporated and desorbed to enter the cooling water condenser (4) together with steam. Mainly condensed with organic solvent) and the condensed liquid is separated into the oil-water separation tank (5) at the bottom, and the wastewater is treated with wastewater and the organic solvent is treated separately.

This method requires a separate utility such as steam and cooling water, and the use of water and steam, using a corrosion-resistant material such as stainless has a disadvantage of expensive equipment.

3) Hot air and temperature controlled catalytic combustion desorption apparatus (FIG. 3 method)

This method has been used in recent years to improve the equipment cost and utility problems of the method of Figure 2 is a method of using a small capacity of the system used in the general catalytic combustion device as a desorption device.

Like this method, the desorption device is operated at the same time as in FIG. 2, and the desorption heat supply method uses hot air instead of the steam heat of FIG. 2, and the VOC generated during desorption is condensed and removed from the condenser using cooling water in the case of FIG. 2. Instead, it is heated by a heater heat to increase the catalytic decomposition temperature to catalyze the treatment.

Desorption method is the adsorption tower mouth. With the outlet dampers 102 and 103 closed and the exhaust fan 2 stopped, the air heated by the heater 701 is discharged to the exhaust hot air pipe and the hot air of 250-450 deg. By supplying hot air of 120-200 ℃ into the adsorption tower (1) by heating and desorption of activated carbon 101, the air containing the VOC generated during the desorption again enters the catalytic combustion device (7) 250 in the catalytic decomposition temperature of the heater 701 After heating up to ℃, it is catalyzed by carbon dioxide and water vapor in the catalyst 703 to be discharged to the atmosphere in a purified state.

Here, the capacity of the desorption apparatus, that is, the air volume of the desorption hot air fan 6, is 3 to 10% of the air volume of the exhaust fan 2, and uses a small capacity.

However, the heat recovery is performed by the indirect heat exchange method by the heat exchanger (8), which has the disadvantage of lowering the heat recovery rate, and the heater capacity must be large because the initial low hot air temperature must be raised to 250 ° C or more, which is required for catalytic decomposition. And there is a disadvantage in that the equipment cost is increased because the heat exchanger (8) is required separately.

4) Circulation and flow rate change type catalytic combustion desorption apparatus (FIG. 4 method)

[This method is a method in which the inventors registered a utility model, Registration No. 0259453]

In FIG. 4, unlike the method of FIG. 3, the first heat recovery method is operated by a full circulation method in which a hot gas is directly circulated without a heat exchanger, rather than by a conventional heat exchanger 8, and oxygen required for catalytic combustion after a certain time elapses. In order to prevent shortage of water and to accumulate moisture generated by catalytic decomposition, and to inject a certain amount of external air and exhaust the air as much as the injected air. It is controlled by desorption hot wind flow rate, so that it is possible to sufficiently catalytic combustion with small heater capacity.

(Please refer to Utility Model No. 0259453 already registered for details)

Operation of the desorption device is made in the same manner as in Fig. 3 when the operation is described in detail as follows.

Adsorption tower mouth. When the outlet dampers 102 and 103 are closed and the exhaust fan 2 is stopped and the desorption device, which is the catalytic combustion device 7, is operated, the first hot air fan 6 and the heater 701 are operated to generate hot air. The generated hot air is desorbed by heating activated carbon 101 in the adsorption tower 1, and the air containing the desorbed VOC is introduced into the catalytic combustion device 7 again by suction of the hot air fan 6, thereby heating the heater 701. The heated air is re-heated by the catalyst 703 while it is combusted and decomposed and then operated in a circulating state to enter the adsorption tower 1 again. Here, initially, the hot air flow rate control valve 901 is almost closed by a temperature (eg, 250 ° C.) set in an automatic temperature controller located at the rear of the heater and is kept slightly open, so that the amount of desorption air is part of the maximum air flow rate of the desorption hot air fan (about 1/5) is controlled to flow only a small amount of air is passed through the heater 701 is heated to a set temperature (for example, 250 ℃), and the heated air is burned and decomposed in the catalyst bed (703) again after the adsorption tower It operates in a circulating state entering (1).

If it continues to operate in such a circulation state, the circulating hot air temperature gradually increases, and the amount of VOC desorbed from the activated carbon 101 layer gradually begins to increase.

Increasing the amount of desorbed VOC inevitably increases the temperature of the circulating air passing through the catalyst bed by the heat of decomposition while passing through the catalyst 703, which desorbs more of the amount of VOC and raises the temperature further.

In addition, by continuously circulating, the desorption hot air temperature rises to prevent the accumulation of moisture generated during the decomposition of the catalyst, thereby opening the air inlet / opening valve 902 and the exhaust air opening / closing valve 903 so that a predetermined amount of catalytically decomposed high-temperature purified air is released to the outside. As it was discharged and introduced to the outside air inflow through the open air inlet and out valve 902.

In this way, since this system is operated in a circulating manner for a predetermined time (about 30 minutes to 1 hour) from the beginning, the VOC discharged by the low catalytic decomposition rate is not discharged to the outside due to the delay of heating due to the characteristics of the heater heating. Since the total amount of air from hot gas is directly introduced into the desorption hot air by heating and catalytic decomposition heat, there is an advantage that the heat contained in the hot gas can be used as 100% desorption hot air, unlike the indirect heat exchange method. There is an advantage that can be used as a heater of a small capacity because the small amount of air is heated by 901.

However, this method is likely to cause a fire due to overheating of activated carbon because the desorption hot air temperature supplied by the heat of catalytic decomposition increases from 250 ° C to 450 ° C by the VOC decomposition heat over time. The risk of fire is particularly high when flammable substances such as paint dust are on the activated carbon.

Therefore, the present invention was devised by applying several improved methods in order to eliminate the risk of fire, which is the most problematic as shown in FIG. 5, while maintaining a heater heating temperature of 250 ° C. for catalytic decomposition.

In order to economically operate the activated carbon adsorption system, the present invention adopts the method of desorption by hot air and catalytic combustion of desorbed VOC, but considers the following technical problems to be safe from fire.

1) The basic method adopts the circulation and flow rate change type catalytic combustion desorption apparatus registered by the inventor (Fig. 4 method: Registration No. 0259453)

By operating the circulation method, VOC minimizes the discharge to the outside to enhance the VOC purification performance when desorption, and the majority of the air coming from the hot gas from the catalytic device to heater heating and catalytic cracking heat flows directly into the desorption hot air. Otherwise, the heat contained in the hot gas can be used as a desorption hot wind of more than 80-90%, and since a small amount of air is initially heated by the flow control valve 901, it can be used as a heater having a small capacity. that.

2) Since the desorption hot air temperature supplied is 250-450 ° C. as the biggest problem while utilizing the advantages of the circulation and flow rate catalytic combustion desorption apparatus of FIG. It should be a way of solving high-risk problems.

In order to achieve such a technical problem, as shown in FIG. 5, the apparatus is configured as follows.

Activated carbon adsorption tower (1) having inlet and outlet opening and closing dampers (102, 103) and exhaust fan (2) and stack (3) for inducing air when the adsorption tower is operated,

Small capacity catalytic combustion device incorporating inlet primary heater 704 and secondary heater 705, pre-catalyst automatic temperature controller 702, and catalyst 703 at the inlet part. 7) and the removable hot air fan (6).

Desorption hot air pipe (9) through which desorption hot air flows, hot air flow rate control valve (901) for adjusting the flow rate by means of a pre-catalyst thermostat signal, and a desorption hot air temperature at a temperature without danger of fire. Open air open / close valve that is opened when the outside air is put in after a certain period of time after being placed in front of the primary heating air engine 10 for mixing the primary heating air with high temperature VOC decomposition hot air to maintain the temperature below 250 ° C). 902 and an exhaust air open / close valve 903 are installed at the rear end of the small-capacity catalytic combustion device and open when some hot air is discharged to the outside.

The present invention shown in Figure 5 has the following other features as compared to the conventional method.

First, as shown in FIG. 4, most of the heating heat and the decomposition heat generated during catalytic decomposition are immediately circulated and reused as desorption heat, thereby maximizing heat use efficiency.

Secondly, the circulation method used in FIG. 4 has the advantage of maximizing the desorption heat recovery effect such as catalytic heat of decomposition, but as desorption is accelerated by continuous circulation, the desorption hot air temperature of the rear end of the catalyst is overheated to 250-450 ° C. In the present invention, the desorption hot air fan 6 having a capacity twice as large as that of the desorption hot air fan 6 used in FIG. 4 is used. The risk of fire was prevented by maintaining the temperature of desorption hot air entering the adsorption tower by mixing primary heating air at ℃ 145-205 ℃.

When here and 4 how the description, for example, to concrete understanding of the present design is the difference between Fig. 5 method 4 scheme When removable hot-air fan (6) capacity selected 5 Nm ³ / min 5 Nm ³ / The capacity of the heater 701 required to raise the minute air from 50 ° C to 250 ° C is 20 kw. In this case, the desorption hot air entering the adsorption tower 1 after catalytic decomposition after a predetermined time is 4.0 Nm ³ / min at 80% circulation. The hot air is initially entered at a temperature of 250 ° C, and VOC increases in the hot air to enter a high temperature of 450 ° C by decomposition heat, and the remaining 20% of the hot air is 1.0 Nm ³ / min of air is discharged to the outside.

In contrast, the present design of Fig. 5 method removable hot-air fan (6) twice in FIG. 4 based capacity 10 Nm ³ / shunt assuming primary heater of 10kw capacity air of 10 Nm ³ / min with a 50 ℃ temperature in a hot-air fan 704 gives to rise to 100 ℃ the first 70% of the hot air of the quantity of rise 100 ℃ 7 Nm ³ / min passing through a primary heating air pipes 10 and 30% of ³ Nm 3 / min is 10kw [ The combined heater capacity of the primary and the secondary is 20 kw, which is the same capacity as that of FIG. 4], and is further heated by a secondary heater 705 having a capacity, and is raised from 100 ° C. to 250 ° C., which is a catalytic decomposition temperature. The hot air ³ Nm 3 / min increase to 250 ℃ is bunhaeyeol while passing through the catalyst bed is made an additional temperature increase by bunhaeyeol initially is desorbed VOC is almost not shown VOC is gradually increased while maintaining the 250 ℃ such as a catalyst before the temperature By rising to 450 ℃ by the hot air is partially discharged to the outside and the rest is passed through the hot air circulation pipe and combined with the primary heated air is sent to the desorption hot air.

Here, for convenience of comparison, assuming that the post-catalyst hot air temperature is 400 ° C., 1.0 Nm ³ / min, which is 1/3 [90% circulation, that is, 10% of the hot air fan capacity] of the high temperature hot air passed through the catalyst [2.5 m ³ / min @ and through the catalyst outlet to 400 ℃] discharged to the outside [flows] at the same time the outside air by the exhaust hot air remaining 2.0 Nm ³ / min - 5.0m ³ / min @ 400 ℃] is a hot air circulation line (9 ) is go out on a first heating primary air 7.0 Nm ³ / min of 100 ℃ coming from the primary heating-air ducts (10) [= 9.6m ³ / min @ 100 ℃] and desorption with a mixture of hot air temperature of 190 ℃ 9.0Nm ³ / min [= 15.3m ³ / min] enters the adsorption tower (1).

In summary, when the two methods are compared, the external emissions corresponding to heat loss are equal to 1.0 Nm ³ / min [= 2.5m ³ / min ＠ 400 ℃], and the desorption hot air related to the desorption efficiency is 400 in FIG. It is 9.9m ＾ 3 / min [= 4.0 Nm ＾ 3 / min] at ℃, while the method of FIG. 5 operates at 15.3m ³ / min [= 9.0 Nm ³ / min] at 190 ° C compared to FIG. The temperature decreased 2.1 times from 400 ℃ to 190 ℃, but the air flow increased from 4.0 Nm ³ / min to 9.0 Nm ³ / min by 2.2 times, so the desorption heat flowed into activated carbon is the same.

As a result, the heat recovery rate and the desorption efficiency have the same effect, and the present design method lowers the desorption hot air temperature to 190 ° C (minimum 145 ° C to maximum 205 ° C), so that the fire safety temperature is lower than 250 ° C [possibility of fire above 300 ° C]. By driving, the fire risk is fundamentally prevented.

The operation of the method of FIG. 5 having the two features discussed above is similar to FIGS. 3 and 4, and the operation of the detachable device is performed at rest.

Exhaust air opening and closing valve (903) located in the exhaust hot air pipe at the rear of the inlet / outlet opening / closing dampers (102, 103) and the exhaust fan (2) is stopped and the exhaust gas inlet after the catalytic combustion device (7). ), And the desorption hot air fan 6, the inlet primary 704 and the rear secondary heater 705 are operated so that the desorption hot air temperature is set to the set temperature of the pre-catalyst automatic temperature controller 702 (for example, 250 ° C.). Until the temperature reaches 250 ° C., the temperature is increased until the temperature of the catalyst reaches 250 ° C., and all flows normally flow from the hot air fan (6). ) Enters the catalytic combustion device (7) and all rises to 100 ° C. in the inlet primary heater (704), 70% of which goes out through the primary heating air engine (10) and the remaining 30% of the rear secondary heater (705). ) And the pre-catalyst temperature rises to 250 ℃ to catalyze VOCs before hot air circulation Out through (9) is combined with the hot air from the primary heating air engine (10).

The combined desorption hot air enters the adsorption tower (1) and heats and desorbs the activated carbon 101. The air containing the desorbed VOC flows back into the catalytic combustion device (7) by suction of the hot air fan (6), and the primary (704) ) And the secondary heater 705 is reheated, and the heated primary heating air and the hot air passing through the catalyst 703 are combined to operate in a circulation state that enters the adsorption tower 1 again.

As it continues to operate in this 100% circulation state, the circulating hot air temperature gradually increases, and the amount of VOC desorbed from the activated carbon 101 layer gradually begins to increase.

Increasing the amount of desorbed VOC inevitably increases the temperature of the circulating air passing through the catalyst bed by the heat of decomposition while passing through the catalyst 703, which desorbs more of the amount of VOC and raises the temperature further.

After a certain period of time while continuing to circulate in this state, a timer signal is received and the exhaust air open / close valve 903 located at the exhaust hot air pipe at the rear end of the inlet / outlet valve 902 and the catalytic combustion device 7 is opened for a predetermined amount (about 10%). As the outside air enters, it goes out to the exhaust pipe after the catalyst, and the remaining air (about 90% of the total amount of hot air fan air) not circulated from the outside is circulated to the desorption hot air.

The present invention has been improved as follows compared to the previous method.

First of all, the most problematic problem in adsorption method is that if a certain amount of VOC is adsorbed, it becomes saturated and VOC is not removed, so the activated carbon must be replaced. It can save tens of millions of won in activated carbon replacement costs.

Secondly, as the desorption and regeneration device that has been used mainly in the past, as shown in FIG. 2, the desorption and desorption by steam heat during operation has been used by the method of removing condensation by cooling condensation, but the equipment cost is high and cooling water and steam, etc. There is a problem that a separate utility is required. By using a small catalytic combustion device, the catalytic decomposition of VOC generated during desorption and desorption by hot air is eliminated. The effect can be obtained.

Third, as shown in FIG. 3, the method using the hot air and the small catalytic combustion device is a simple control method based on the temperature before the catalyst, and the heater capacity is increased, and the heat recovery rate is low by the indirect heat exchange by the heat exchanger. The temperature control is the desorption hot air flow rate control method to lower the heater capacity, and the desorption hot air catalytically decomposed without the heat exchanger is configured in an 80-90% circulating manner to achieve a significant increase in the heat recovery rate.

Fourth, the present invention is gradually heated by the continuous circulation of the desorption hot air as shown in Figure 4, the hot air of 400 ℃ or more hot water flows directly into the activated carbon there is a risk of fire according to the present invention increases the capacity of the desorption hot air fan, and the primary heating by the increased capacity By mixing with the low temperature air through the air pipe (10) by spraying the heated desorption hot air temperature to the activated carbon at 145-205 ℃ it is possible to obtain the effect of preventing the fire hazard due to the high temperature desorption hot air.

As a result, the present invention not only reduces the cost of replacing excessive activated carbon and is inexpensive, but also adopts the desorption hot air circulation system to increase the heat recovery rate by 80-90% with the use of desorption heat of decomposed heat, and achieve various comprehensive effects without risk of fire without deterioration of thermal efficiency. That's how it is.

1 is a flow chart of a non-removable general adsorption tower

2 is a flow chart of a cooling condensation type desorption apparatus for steam heat desorption and desorption VOC.

Figure 3 is a flow chart of the hot air and temperature controlled catalytic combustion desorption apparatus

Figure 4 is a flow diagram of the circulation and flow rate type catalytic combustion desorption apparatus

5 is a flow chart of the circulation and fire safety type catalytic combustion desorption apparatus

* Explanation of symbols for main parts of the drawings

1 ...... Adsorption Tower 101 ...... Activated Carbon

102..Adsorption tower entrance damper 103 ... Adsorption tower exit damper

104.Inlet steam open / close valve 105 ... Outlet steam open / close valve

2 ...... Exhaust fan

4 ....... Condenser 5 ......... Oil Separator

6 ..... Desorption hot air fan 7 ....... Catalyst combustion device

701 Heater 702 Thermostat

703 ... catalyst 704 ... primary heater

705 ... Secondary Heater 8 ...... Heat Exchanger

9 ...... Hot air circulation piping 901 .... Hot air flow control valve

902 Exhaust air open / close valve 903 Exhaust air open / close valve

10 ...... Primary heating air engine

Claims (1)

In constructing the system as a facility that is applied to a device for desorption and regeneration of activated carbon in the activated carbon adsorption column Activated carbon adsorption tower (1) equipped with adsorption tower inlet and outlet opening and closing damper, exhaust fan (2) and stack (3) to induce air during painting A device for desorbing and regenerating activated carbon during idle operation. The catalytic combustion device 7 and the catalytic combustion device having a primary heater 704 at the inlet part, a secondary heater 705 at the rear part, and an oxidation catalyst in series at the rear part of the secondary heater. It is equipped with a desorption hot air fan (6), which is located in front and draws desorption hot air and passes it through the catalytic combustion device to the desorption hot air. Adsorption column desorption hot air from the catalyst layer outlet of the catalytic combustion device and the inlet connection pipe with a hot air flow rate control valve 901 that gradually increases and adjusts the initial flow of hot air in the catalytic combustion device inlet to the pipe connecting each device. Hot air circulating pipe connected to the inlet and hot air flow control valve, connected to the timer and connected with a timer Piping Section A primary heating air pipe (10) connected from the hot air outlet to the hot air circulation pipe between the catalytic combustion device primary heater and secondary heater; Circulation and fire safety catalytic combustion desorption device comprising a system having a series of systems in which an automatic temperature controller 702 located at the front of the catalyst layer is installed in conjunction with a flow control valve as a control device.