KR200259456Y1 - Low Energy Electric Heat Drying Type Paint Booth - Google Patents

Abstract

This design is applied to painting facilities such as automobile painting booths that work alternately in an enclosed space that has been painted and dried. Previously, only the booths, air supply facilities, exhaust facilities, and dry heat supply facilities by diesel burners were used. (Figure 1).

However, recently, as regulations on volatile organic compound vapors (VOCs) evaporated and released from paints during painting and drying operations have been tightened, an adsorption tower was installed as a VOC removal facility (Figure 2).

However, the activated carbon filled in the adsorption column is saturated and cannot be adsorbed when a certain amount is adsorbed to remove the VOC, so the activated carbon needs to be replaced every certain period and there has been a problem of excessive consumption cost.

In order to solve this problem, a separate activated carbon regeneration device has been installed, and a catalytic combustion device has been installed and used as an economical and efficient desorption device (FIG. 3).

However, the driving method of the existing car paint booth itself is a method of high energy loss, and additional energy is required for the operation of the desorption device.

In other words, the energy loss is that when the first burner is operated, the hot gas generated by combustion heats the air blown from the air supply fan by heat exchange and heats it.In this process, the burner combustion gas is discharged into the atmosphere after heat exchange. It is emitted at a high temperature above ℃ containing a large amount of heat, which means a large energy loss.

Second, in order to prevent quality deterioration during painting, the temperature inside the booth is maintained at 25 ~ 35 ℃. In winter, when the outside air temperature is low and ventilation is performed, the temperature inside the booth cannot be maintained at the proper temperature. It activates and heats up. However, due to the nature of the painting work, all the air supplied is exhausted, which means that all the heated heat is released into the atmosphere.

Third, the catalytic combustion device used for desorption is heated with a heater to catalytically decompose the VOC generated during desorption. In this process, a large amount of VOC decomposition heat is generated, and the air exiting the catalytic combustion device has a high temperature of 300 to 500 ° C. Although it recovers some heat through the heat exchanger, the temperature emitted to the atmosphere after heat exchange is also 200 ~ 400 ℃, which contains a lot of heat, which means energy loss.

Therefore, the present invention is a facility that basically saves about 75% energy compared to the conventional method by essentially reconstructing the system to recover the three heat losses.

The feature of the present invention is to save energy by using the direct heat supply method using the clean energy electricity to prevent the first heat loss and using both the heat of decomposition of the desorbed VOC as dry heat.

In order to minimize energy consumption during winter painting, which is the second energy consumption factor, the VOC is continuously removed with high efficiency to return air to the stack.

In order to prevent energy loss due to the discharge of the high-temperature exhaust gas into the atmosphere of the catalytic combustion apparatus, which is a desorption apparatus, which is the third energy loss factor, the exhaust gas is configured in a completely circulating manner. As a result, it also increases the air pollution prevention effect by eliminating VOCs emitted to the atmosphere.

In order to satisfy these characteristics, the core concept was to supply the heat source of drying heat as a catalytic combustion device heater so that the hot gas of 400-500 ° C. at the outlet was used as the drying heat and activated carbon desorption heat with the heating of the heater and the decomposition heat of VOC.

The optimum system was devised by installing the adsorption tower exit exhaust air return facility and various control devices.

Description

Low Energy Electric Heat Drying Type Paint Booth

The present invention is applied to an automobile paint booth facility where painting and drying work is carried out in a booth. The main purpose of the invention is to dramatically improve energy consumption than conventional automobile paint booths and to evaporate during drying (Volertile Oraganic Compound: VOC) Is effectively removed.

In addition, the conventional paint booth and VOC treatment facilities have been developed and developed, respectively, but the present invention combines the two facilities to develop and develop an optimal method.

In order to effectively explain and easily understand the present invention in the future, the following three categories will be described.

(1) Car paint booth driving method

The automobile paint booth currently used has the structure shown in FIG.

In painting work, a car is placed in the booth 1, and a worker works with a spray paint machine for about 20 to 30 minutes.

At this time, the air supply fan inlet damper 201 is opened and the air supply fan 2 is operated to blow air into the upper part of the booth while the dry air circulation damper 202 is closed in order to protect workers' health, improve paint efficiency, and promote natural drying. At the same time, run the exhaust fan (3) and exhaust it through the lower pit.

At this time, the paint mist discharged by scattering is first removed from the filter laid on the bottom of the booth and secondly removed from the filter 101 installed in the middle of the exhaust duct, and then discharged to the outside air.

When the painting work is completed, the worker comes out of the booth and dries it while sleeping for about 10 minutes in the same state as above.

When the natural drying is finished, the drying work is performed. The drying time is about 20 minutes in summer and about 40 minutes in winter.

In the drying operation, when the air supply fan inlet damper 201 is closed, the dry air circulation damper 202 is opened, and the air supply fan 2 and the burner 4 are operated, the air is heated by burner combustion heat while the exhaust fan 3 is stopped. Will descend from the top of the booth and continue to circulate through the circulation duct.

When the circulating dry air temperature reaches the upper limit temperature (typically 60 to 80 ° C.) set by the temperature controller 102 in the booth, the burner 4 stops operating, and when the set lower limit temperature is reached, the burner 4 is operated. It is configured to dry at a range of dry air temperatures.

When the drying work is finished, the process goes into the cooling process. Like the painting work, the cooling is performed by supplying and exhausting air to cool the heated material in the booth, and the cooling time is usually 15 minutes.

Like this, the painting booth of an automobile is performed through painting, natural drying, heating drying, and cooling.

However, there is one thing different from the above-described working method in winter, which is to operate the burner 4 to maintain the temperature inside the booth at 15 ° C. or more even at the temperature of sub-zero air temperature even during painting.

The reason why the temperature inside the booth is maintained during painting in winter is that when the temperature in the booth is low, the paint does not adhere to the surface of the car paint and the part flows down, resulting in poor painting condition.

(2) VOC treatment method of automobile booth discharge

Until recently, the painting booths of automobiles have been installed and operated in the manner shown in FIG. 1, but the VOC removal device has been implemented in accordance with the emission control of Volatile Organic Compounds (hereinafter referred to as VOCs) evaporated from paint solvents. It became necessary.

As the VOC removal device, as shown in FIG. 2, the structure is simple and the equipment cost is low by filling the activated carbon 501 in the simple container 5 in the simplest manner and then passing the VOC thereon to remove the adsorption. It has been used the most until recently.

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 3000kg of organic solvent is used and evaporates a year, the amount of activated carbon used is 8500-10000kg and the replacement cost is 8,500,000-10,000,000 won.

In order to solve this problem, we started to apply desorption and regeneration of activated charcoal. In the past, a method of condensing VOC and steam desorbed in the cooler after desorption by applying heat with steam has been used. In addition to the need for equipment, the use of corrosion-resistant materials such as stainless steel was very limited due to the high cost of equipment. Therefore, recently, in the case of a drying operation in which the activated carbon adsorption tower 5 does not operate like in FIG. 3 or when the operation is finished, a separate desorption device is installed and desorption and regeneration is used. The desorbed VOC after desorption is used in a catalytic combustion device using platinum or palladium as a catalyst and then discharged into the atmosphere after combustion decomposition as in the following reaction formula.

200 to 350 ℃

(Figure 3 is the state that the inventor of the present invention has acquired the utility model as the “1 tower type adsorption / desorption type adsorption tower” which is a VOC removal facility for automobile paint booth)

Since this method is closely related to the description of the present invention, it will be described in more detail as follows.

The concept of the desorption method is that the activated carbon is desorbed by the hot air heat-exchanged in the heat exchanger 8 by the air heated by the heater 701, and the VOC generated during the desorption is catalytically combustion-decomposed in the catalytic combustion device 7 to the atmosphere. This is how it is discharged. At this time, the capacity of the desorption device, which is the amount of desorption hot air fan, is 5-10 of the weight of the exhaust fan (3) in consideration of the installation cost, operation cost, desorption effect, desorption time, and explosion prevention of activated carbon and desorption device which are closely related to desorption heat amount. Select and use about%.

For example, if the adsorption tower treatment capacity is 300 m 3 / min, the desorption device capacity is about 15 to 30 m 3 / min.

The reason for selecting and using 5 ~ 10% of the exhaust fan weight is that if the capacity of the desorption device is excessively large, the desorption equipment cost and operation cost are expensive, and if it is too small, the desorption time becomes long and the desorption time is severe. This is because the amount of heat supplied is so small that the desorption is hardly performed due to the heat loss.

Next, the driving method of this method will be described in detail.

Adsorption tower mouth. When the outlet dampers 502 and 503 are closed, and the desorption unit is operated while the exhaust fan 3 is stopped, the desorption hot air open / close valve 601 opens to open the hot air supply fan 6 and the heater 701 of the catalytic combustion device. It is operational.

At the initial stage of operation, outside air flows into the adsorption tower 5 as it is through the heat exchanger 8, passes through the activated carbon bed, and then exits and is heated to a predetermined temperature (usually 300 ° C.) by the heater 701 of the catalytic combustion device, followed by a catalyst bed ( 702 and the heat exchanger (8) is exhausted.

Of course, at this time, the activated carbon bed inlet temperature is low, so no desorption occurs, and therefore, there is no VOC combustion decomposition in the catalyst bed.

Next, since the heated air of 300 ° C. has already passed through the heat exchanger 8, the outside air entering the heat exchanger 8 is increased to about 100 ° C. and enters the adsorption tower 1. At this time, since the inlet temperature of the activated carbon layer is increased to 100 ° C., VOC desorption starts to occur at a small amount, and the air containing a small amount of VOC is heated to 300 ° C. again in the heater 701 to enter the catalyst 702 layer. A small amount of VOC is burned and decomposed to generate heat of decomposition, and the air passing through the catalyst layer 702 is discharged through the heat exchanger 8 while the temperature is slightly increased (350 ° C.).

If this process is repeated, the temperature flowing into the activated carbon 101 layer gradually increases, and thus the amount of VOC desorption increases, and the heat of VOC decomposition in the catalyst layer gradually increases, so that the air temperature passing through the catalyst layer through the heat exchanger also increases to 200-300 ° C. It enters the desorption hot air.

As a result, when a certain time has elapsed since the initial operation, it is operated in a state of equilibrium and the equilibrium temperature is operated to the phase shown in FIG.

Here, the capacity of the heater 701 is required to increase the amount of desorption air from the initial temperature to the temperature (200 to 400 ° C.) required for catalytic combustion, and based on the temperature 300 ° C. required for catalytic combustion, about 4 kW per 1 Nm 3 / min. For example, considering that the exhaust fan capacity of automobile paint booth is 300 ~ 400㎥ / min and the amount of activated carbon is relatively small, the capacity of desorption device is 5% of the minimum capacity exhaust fan, 15 ㎥ / m at 150 ℃. Minutes (10 Nm3 / min) are required, in which case a heater of about 40 kW is required.

However, a heater capacity of 40 kw does not continuously operate at 40 kw calories throughout the desorption time, and when the temperature flowing into the heater is gradually increased, the heating calories are gradually reduced by the heating calorie control by the automatic temperature control 703.

That is, the heater heating is automatically adjusted to be always maintained at 300 ° C. by setting the preset catalytic combustion temperature, for example, 300 ° C., so that the air introduced at room temperature operates at a maximum heat of 40 kw but gradually increases. When the temperature of the desorption air rises, the heat amount gradually decreases, and when the equilibrium temperature (about 150 ° C.) is reached, it is operated while heating with a heat amount of about 20 kw.

What should be noted here is why 20 kW of additional heat is required even in equilibrium when the amount of heat generated by the decomposition of VOC in the catalyst layer is used as heat for desorption.

This is because the exhaust gas which has passed through the catalyst bed is discharged with a large amount of heat, which is discharged to the atmosphere after heat exchange, so that a lot of heat loss occurs.

(3) Calculation of fuel consumption and dry heat loss

As described above in (1), the supply of dry heat during the drying operation is supplied by burning fuel (light oil or LNG) in the burner 4.

Burner capacities typically use 150,000 kcal / hour.

The burner operation time differs depending on the warmth of the booth and the winter and summer, ie the outside temperature.In the case of the relatively warm booth used recently, the winter operation starts for about 10 minutes for a total drying time of 40 minutes and then starts every 3 minutes. The actual run time is about 25 minutes, and during the summer the initial run time is about 6 minutes for 20 minutes, followed by 3 minutes, then the actual run time is about 14 minutes.

If you calculate the calories based on the burner capacity and the actual operating time when you build one car, it takes about 60,000 kcal in winter, about 34,000 kcal in summer, and converts it via diesel to about 7 L in winter and about 7 L in summer. It takes 4L.

However, in the winter, as described above, the burner is operated even during the painting operation to maintain the temperature in the booth, and thus requires about 75,000 kcal of heat and about 8 L of heat required to operate the painting for 30 minutes.

Normally, the number of automobile paints is about 100 flat roots per month, so it takes about 1,500 L in winter, about 400 L in summer, and about 500-600 L in spring and autumn.

However, in the drying operation, all of the supplied heat supply of dry heat is not used for actual paint drying, and heat loss of about 30% occurs.

The heat loss occurs when the burner flue gas is heated through the flue-gas stack after heating the dry air in the combustion chamber and heat exchanger.

In other words, the exhaust gas temperature to the atmosphere is 260-300 ℃, and the exhaust gas of burner 150,000 kcal / hour is about 400 Nm3 / hour (excess air ratio 2), so the heat containing exhaust gas is as follows.

400 Nm3 / hr × 1.3 kg / Nm3 × 0.26 kcal / kg- ℃ × 300 ° C ≒ 41,000 kcal / hr (41,000 kcal / hr) / (150,000 kcal / hr) × 100 ≒ 30%

Here, despite the large amount of heat loss, the reason for adopting the indirect heat exchange method is to prevent the unaffected dust such as unburned carbon and toxic gases such as nitrogen oxides from diesel ignition and combustion. For sake.

The present invention considered the following technical problem.

(1) Maximize energy efficiency by eliminating heat loss of combustion exhaust gas during drying operation. This reduces the heat loss corresponding to 30% of the dry feed heat.

(2) To save energy as much as possible by circulating and recovering the heat energy operated for maintaining the temperature inside the booth during winter painting work. This is greater than the heat used for drying in winter, and the energy saving effect is great when recovering it.

(3) The use of thermal energy, along with the supply of dry heat, also uses the treatment of VOC generated during desorption and desorption at the same time.

This method solves the problem of low efficiency by utilizing only about 50% of VOC decomposition heat of 25000kcal as well as a large amount of heat loss of 20kw which is discharged into the atmosphere after heat exchanger after catalytic combustion. It is.

(4) The basic unit of diesel oil and electric energy is about 65 won per kilowatt of heat energy for 680 won per liter of diesel, and 65 won per kilowatt for electricity. However, the electrical energy is clean energy, easy to control, and when considering the advantages associated with the above three items, the system change to the electric method is considered.

In particular, the price of diesel is lower than that of developed countries in relation to the government's energy policy. So, the price of quasi-energy is expected to increase to some extent in the coming years, but the price of diesel is expected to rise to 70-80% in the past few years. It is expected to change the heat supply more advantageously because it is expected.

(5) The VOC treatment performance during desorption should be highly efficient.

1 is a flow chart of a conventional general automotive paint booth

2 is a flowchart of an automobile paint booth with a simple activated carbon adsorption tower.

3 is a flowchart of an automobile paint booth with a catalytic combustion detachable adsorption tower.

4 is a flowchart of a low energy electric dry car painting booth with a catalytic combustion desorption tower.

* Explanation of symbols for main parts of the drawings

1.painting booth

101 ... filter

102.Drying temperature thermostat

103.The painting temperature automatic temperature controller

2.Air supply fan

201 ... Air supply fan opening and closing damper

202 ... Dry air circulation opening and shutting damper

3.exhaust fan

4 ... Burner

5.Adsorption tower

501 ... activated carbon

502.Adsorption Tower Entrance Damper

503.Adsorption tower exit opening and closing damper

504 ... exhaust air circulation duct opening and shutting damper

6.Hot air supply fan

7.catalyst combustion device

701 ... heater

702 ... Catalyst

703 ... Catalyst Inlet Temperature Thermostat

704 ... Catalyst layer temperature difference thermostat

8 ... heat exchanger

9.Hot drying hot air sprayer

901 ... Drying Hot Air Flow Control Valve

902.Hot drying hot air supply pipe

903 ... Timer to shut off hot hot air flow control valves

10 ... Detachable high temperature hot air supply piping

The basic system of the present invention is shown in FIG.

The basic concept was devised as follows considering the technical problem.

(1) Dry heat and activated carbon regeneration desorption heat are supplied to electric energy (heater 701) in one place.

(2) VOCs generated during drying and desorption generated VOCs are burned and decomposed by a catalyst in a heating furnace of the heater 701 which supplies drying heat and desorption heat, and completely supplies dry heat and desorption heat to the purified hot air. Configure in a cyclic manner.

Therefore, the efficiency of heat use is maximized and the evaporated VOC is continuously circulated while drying, and the desorbed VOC is treated in a circulating manner with no external discharge after high efficiency removal, so that the high efficiency removal close to perfect in VOC removal performance is possible. .

Particularly during this process, the VOC decomposition heat is very large, and this system saves energy because it recycles all of the decomposition heat and uses it as drying and desorption heat.

(3) To cope with the regulation of VOC and to use circulation of winter exhaust air, it is possible to remove more than 90% of VOC from activated carbon adsorption tower at the time of painting by continuous desorption and regeneration of activated carbon in the drying operation.

(4) During the winter painting work, in the energy supply heating for maintaining the temperature inside the booth for smooth painting, the exhaust air that has passed through the activated carbon was circulated about 80 to 90%, and then heated again by putting it back into the booth. Most of the heat is recovered to save energy. However, this energy saving needs to continuously remove high-efficiency VOC during painting, and if VOC removal is insufficient, a large amount of VOC is contained in the circulating air, which may worsen the workplace environment.

However, the present invention can be applied to this energy saving method because it is configured in such a way that the continuous high efficiency activated carbon adsorption removal by the effective desorption method.

(5) Maximize energy use efficiency by configuring all systems by automatic control method such as applying automatic control method in dry heat supply method.

The operation method of FIG. 4 constituted by the above system configuration basic concept is as follows.

During painting, open the air supply fan inlet damper 201 with the dry air circulation damper 202 closed, operate the air supply fan 2 to blow air into the upper part of the booth, and operate the exhaust fan 3 at the same time. Exhaust through the pit.

At this time, the paint mist discharged by scattering is first removed from the filter laid on the bottom of the booth and secondly removed from the filter 101 installed in the middle of the exhaust duct, and then the VOC discharged during coating is removed from the activated carbon adsorption tower 5 and then to the outside air. Discharged.

Here, in the winter season, the exhaust air circulation duct and the opening / closing damper 504 are provided to reduce the energy supplied to maintain the temperature in the booth, and the adsorption tower outlet opening / closing damper 503 is closed simultaneously with the operation of the heater 701 and simultaneously discharged into the stack. Opening the exhaust air circulation opening and closing damper 504 installed in the air circulation duct is introduced most of the exhaust air back to the air supply fan chamber, and part is discharged to the atmosphere through the branch pipe. At this time, the heater is not operated continuously but is operated by the temperature controller 103 installed in the booth 1 and then turned off while maximizing efficiency.

In the drying operation, the catalyst combustion device (7), the hot air supply fan (6), and a connecting pipe are provided for supplying drying heat and desorption of activated carbon. The air supply fan inlet damper (201) is operated with the exhaust fan (3) stopped. Close the air and open the dry air circulation damper 202 and operate the heater 701 and the hot air supply fan 6 installed in the air supply fan 2 and the catalytic combustion device 7, and the heated air is heated to 300 ° C. or higher by the heater heat. The hot air is blown through the hot air injector (9) through the high temperature hot air supply pipe (902) for drying and supplied with the circulating air blown from the air supply fan to the upper part of the booth to supply dry hot air. After the painted paint is dried down to the booth and operated in a circulation manner entering the air supply fan 2 through the damper 202 of the circulation duct.

The amount of heat supplied by the circulating drying hot air closes the drying hot hot air flow control valve 901 for a predetermined time (about 3 minutes) set in the operation initial timer 903, so that most hot hot air is used for detachment. After generating the desorption VOC to generate a large amount of heat of decomposition, it is configured to be adjusted by the temperature set by the automatic temperature controller 102 in the booth (typically 80 ° C.). The drying temperature is dried by a signal sent from the automatic temperature controller 102. The flow rate is adjusted so that the high temperature hot wind flow rate control valve 901 is dried at the set temperature.

Therefore, since the temperature flowing into the booth is lower than the set temperature after 3 minutes of the initial operation, the valve is completely opened and most of the high temperature hot air is used as dry heat, and sufficient heat is supplied, and when the temperature difference gradually decreases and approaches, the valve 901 Is gradually closed to gradually reduce the flow rate so that the supply calorie control can be achieved.

The reason for using the high temperature hot air as the desorption heat for several minutes during the initial operation is to increase the desorption efficiency and to put the drying heat together with a large amount of desorption VOC decomposition heat to relatively lower the heater 701 supply heat and lower the heater capacity.

On the other hand, after the hot air passing through the catalytic combustion device for desorption of activated carbon is sent to the high temperature hot air for desorption for the first few minutes of operation, the hot air is sent to the dry heat supply air, and the remaining part is sent to the activated carbon. Desorbed VOC after desorption of activated carbon 501 by desorbing activated carbon 501 through the high temperature hot air supply pipe 10 for desorption and the air sent to the inlet of the adsorption tower 5 and discharged by the amount of hot air put for drying Containing air enters into the catalytic combustion device 7 again by suction of the hot air supply fan 6, and the incoming air passes through the catalyst layer 702 in a heated state by the heater 701 and then removes catalytic combustion decomposition and then again. It consists of an outgoing circulation structure.

Here, the amount of desorption hot air is initially used mostly as desorption hot air, but a relatively small amount flows in. However, as the amount of dry hot air decreases, the amount of desorption hot air increases in inverse proportion to the amount of desorption. Raised. .

The operation of the heater 701 in the catalytic combustion device 7 controls the amount of heat of the heater so as to enter the temperature (usually 300 ° C.) set at all times by the automatic temperature controller 703 provided in front of the catalyst 702.

A thermostat 704 is also provided at the rear end of the catalyst bed and turns off the heater when the set temperature (usually 600 ° C.) or more is reached. The role of this device is to prevent overheating (over 600 ℃) by the large amount of combustion heat caused by excessive VOC inflow, preventing the damage of catalyst by high temperature and preventing explosion by blocking the inflow of high concentration (VOC 5000ppm or less) in advance. And the role of the state.

In conclusion, the present invention is a device composed and operated in a series of systems shown in FIG. 4 to achieve the basic concept.

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

1 is a method that has been used so far, there is no separate VOC treatment device has not been able to cope with the recent VOC regulation, and the system itself has a lot of energy loss due to the heat loss of combustion exhaust gas.

Figure 2 is the installation of activated carbon adsorption tower (5) to remove VOC, the problem of VOC regulation can be solved, but this method is only the adsorption tower, the operation cost excessive to replace activated carbon due to the consumption of activated carbon due to the continuous adsorption of VOC (About 5,000,000 ~ 15,000,000 won per year) is a problem that takes.

Therefore, the problem of excessive activated carbon consumption was solved by using the method of regenerating activated carbon by installing the desorption apparatus shown in FIG.

The present invention achieves the simplification and energy saving of the system by changing the dry heat supply method from diesel to electricity and combining VOC treatment and dry heat supply simultaneously with the complete treatment of VOC by the method of adsorption and desorption of VOC in the fourth degree method. In particular, by using the decomposition heat of VOC as 100% drying heat, energy consumption can be further reduced. In addition, the energy consumption required to maintain the temperature inside the winter booth was circulated to exhaust air, assuming the high efficiency of VOC removal, and energy was saved.

In summary, it can be said that the purpose of the present invention is to reduce the operating cost through energy saving compared to the conventional method, especially the third method.

Although the effects of the above inventions have been described, they are rather abstract, for example, to present them quantitatively.

Here, since FIG. 1 and FIG. 2 are not appropriate methods, a comparison between FIG. 3 and FIG.

[Design Criteria]

Exhaust Facilities: Automobile Paint Booth

1 day car paint quantity: average 4 (100 per month)

Operating time: painting; 20 to 30 minutes (air supply and exhaust)

Natural drying; 10 minutes (air supply and exhaust)

dry ; Summer season, 20 minutes (air circulation)

Spring and Autumn season, 25-30 minutes (air supply circulation)

Winter, 40 minutes (air circulation)

Cooling ; 15 minutes (air supply and exhaust)

Exhaust fan capacity: 350㎥ / min

VOC Type: Toluene, Xylene, etc.

VOC emissions: 10 Kg / day (2.5 kg / set)

VOC removal performance: over 90%

(1) third way

(A) Dry heat supply device

※ Burner Capacity: 150,000 kcal / hour

※ Fuel used: diesel

※ Air supply fan air flow: 350㎥ / min

※ Dry heat supply method: Indirect heat exchange

※ Calorie supply for one drying

-Summer: 34,000 kcal

-Spring and Autumn: 40,000 ~ 50,000 kcal

-Winter season, drying time: 60,000 kcal

When painting: 75,000 kcal

※ Actual supply calories (70% of calorific value) excluding lost calories taken by combustion exhaust gas in one drying unit

-Summer: 24,000 kcal

-Spring and Autumn: 28,000 ~ 35,000 kcal

-Winter season, drying time: 42,000 kcal

When painting: 52,000 kcal

※ Light oil usage

-Summer: 4 L x 100 sets / month = 400 L

-Spring and Autumn: 5 ~ 6 L × 100 units / month = 500 ~ 600 L

-Winter season, drying time: 7 L × 100 units / month = 700 L

When painting: 8 L × 100 units / month = 800 L

(B) VOC removal facility

* Processing way:

-VOC generated during painting; Activated carbon adsorption treatment

-VOC generated on drying and VOC generated on desorption; Catalytic combustion cracking treatment

※ Capacity: 10N㎥ / min

※ Heater capacity: 40kw (20N ℃ of 10N㎥ / min air rises to 300 ℃)

※ The amount of heat required for catalytic combustion during drying (based on 50% heat exchange efficiency)

-Summer: 6,000 kcal (40kw × 0.5 × 20 minutes × 60 × 0.252kcal / kw)

-Spring and Autumn: 9,000 kcal (40kw × 0.5 × 30 minutes × 60 × 0.252kcal / kw)

-Winter: 12,000 kcal (40kw × 0.5 × 40 minutes × 60 × 0.252kcal / kw)

※ Hot air supply fan: 15㎥/min＠150℃×100mmAq×1.5kw

※ Catalyst: 14L (Based on 40000 / h space velocity)

※ Catalyst inlet temperature: 300 ℃

※ VOC removal efficiency when desorption: more than 95%

※ VOC outlet discharge: 2.5kg × (1-0.95) = 0.125kg

(2) fourth way

(A) Dry heat and desorption heat supply system and VOC removal facility

※ Heater: 60kw

※ Fuel used: electricity

※ Air supply fan air flow: 350㎥ / min

※ Dry heat supply method: Direct hot air supply by electric heating

※ Supply calories when drying 1 unit (actual calorific value of the 3rd system)

-Summer: 24,000 kcal

-Spring and Autumn: 28,000 ~ 35,000 kcal

-Winter season, drying time: 42,000 kcal

When coating: 10,000 kcal (Based on 80% heat recovery by exhaust return)

※ The amount of heat required for desorption

-Summer: 6,000 kcal

-Spring and Autumn: 9,000 kcal

-Winter: 12,000 kcal

※ The amount of heat generated by catalytic combustion decomposition of VOC:

25,000 kcal (2.5kg-VOC × 10,000 kcal / kg)

※ Calories to be supplied purely

Supply calories during drying + Desorption calories-Catalytic combustion cracking heat of VOC

-Summer: 24,000 + 6,000-25,000 = 5,000kcal

-Spring and Autumn: 32,000 + 9,000-25,000 = 16,000 kcal

-Winter season, dry season: 42,000 + 12,000-25,000 = 29,000kcal

When coating: 10,000 kcal (Based on 80% heat recovery by exhaust return)

※ Average calorie supply (pure calorie supply / drying time)

Summer: 5,000 / 20 = 250 kcal / min (16kw)

-Spring and Autumn: 16,000 / 30 = 530 kcal / min (34kw)

-Winter, Drying: 29,000 / 40 = 725 kcal / min (48kw)

When painting: 10,000 / 20 = 500 kcal / min (32kw)

※ Processing Method:

-VOC generated during painting; Activated carbon adsorption treatment

-Catalytic combustion decomposition of VOC generated during drying and VOC generated during desorption at the same time as supplying dry heat

※ Capacity: 15N㎥ / min

※ Heater capacity: 60kw (20 ℃ rise of l5N㎥ / min air 300 ℃)

* 20% margin applied

※ Hot air supply fan: 23㎥/min＠150℃×100mmAq×2.2kw

※ Catalyst amount: 20L (Based on 40000 / h space velocity)

※ Catalyst inlet temperature: 300 ℃

※ VOC removal efficiency when desorption: more than 95%

※ VOC outlet discharge: 2.5kg × (1-0.95) = 0.125kg

<Economy Review>

(1) Equipment cost

The part of the facility cost of the fourth degree method is lower than that of the third degree method but the unnecessary part of the fourth degree method is an unnecessary facility of the fourth degree method. The burner 4 and the heat exchanger located in the combustion chamber and the heat exchanger and the catalytic combustion device 8) the cost of equipment is reduced due to the disappearance.

On the contrary, the fourth degree system increases the installation cost by adding the exhaust air return duct facility which is about twice as large as the third degree method and the winter operation.

Overall, the fourth degree method is somewhat cheaper than the third degree method, but the difference is not large.

(2) annual running cost

The core of the present invention is the reduction of operating costs due to energy saving.

The operating costs of the exhaust fan and the supply fan are the same, but the operating cost is the difference in energy consumption due to the difference in energy consumption and the energy saving through the improvement of the dry heat supply system and the energy recovery through the exhaust air return in winter.

(A) Annual energy expenditure of the third degree system

The energy costs of FIG. 3 can be obtained from the diesel costs and the electricity charges for desorption.

In the above embodiment

※ Light oil usage

-Summer: 4 L × 100 sets / month = 400 L

-Spring and Autumn: 5 ~ 6 L × 100 units / month = 500 ~ 600 L

-Winter season, drying time: 7 L × 100 units / month = 700 L

When painting: 8 L × 100 units / month = 800 L

Summer Consumption: 400 L × 3 months = 1,200 L

Spring and Summer consumption: 550 L × 6 months = 3,300 L

Winter Consumption: 1,500 L × 3 months = 4,500 L

Annual diesel usage = 1,200 + 3,300 + 4,500 = 9,000 L

Annual diesel consumption = 9,000 L × 680 won / L = 6,120,000 won

※ electric charge for removal

Average desorption heat 20kw × Annual total desorption time (total drying time) × 65 won / kwh = 20 kw × Average 30 minutes-dry / large × 1 hour / 60 minutes × 100 units / month × December / year × 65 yuan / kwh ≒ 800,000 won

(B) Annual energy expenditure of the fourth degree system

The energy costs of FIG. 4 can be obtained from electricity bills.

In the above embodiment

※ Average calorie supply (pure calorie supply / drying time)

Summer: 5,000 / 20 = 250 kcal / min (16kw)

-Spring and Autumn: 16,000 / 30 = 530 kcal / min (34kw)

-Winter, Drying: 29,000 / 40 = 725 kcal / min (48kw)

When painting: 10,000 / 20 = 500 kcal / min (32kw)

Summer electricity fee: 16kw × 20 minutes-drying / large × 1 hour / 60 minutes × 100 units / month × 3 months × 65 won / kwh = 104,000 won

Spring and Autumn Consumption: 34kw × 30min-Dry / Land × 1hr / 60min × 100set / Month × 6month × 65won / kwh = 663,000won

Winter Consumption, Drying Time: 48kw × 40 minutes-Dry / Land × 1 hour / 60 minutes × 100 units / month × 3 months × 65 won / kwh = 624,000 won

Painting time: 32kw × 20 minutes-Painting / large × 1 hour / 60 minutes × 100 units / month × 3 months × 65 won / kwh = 208,000 won

Annual electricity bill = 104,000 + 663,000 + 624,000 + 208,000 ≒ 1,600,000

As a result of this study, the annual energy cost is about 6,920,000 won for the third degree method and 1,600,000 won for the fourth degree method, which saves about 75%.

In conclusion, although the difference in energy consumption is equal to 65 won per 1 kwh of both diesel and electricity, in case of the third degree method, the heat loss is 30% due to the first burner combustion flue gas emitted to the atmosphere, and the second VOC itself in the catalytic combustion device. The heat of decomposition is very high at 25,000kcal per unit, of which more than 50% of heat loss is caused by the heat exchanged to the atmosphere after heat exchange, and the difference in heat is 15% because there is no exhaust air return device during the winter coating.

Claims (1)

It is a facility to be applied to painting facilities such as automobile painting booths that work alternately in a closed space that has been painted and dried, and has one adsorption tower 5 and a catalytic combustion device 7, During painting work, outside air is put in and exhausted to protect workers and improve the quality of painting. An air supply fan (2) for introducing the outside air to blow the paint particles and the volatile organic compound vapors scattered during the painting operation from the top to the bottom to blow them out; An exhaust fan (3) through which the air introduced through the air supply fan ventilates the coating booth and guides the adsorption tower and then blows through the adsorption tower to be discharged to the atmosphere; A filter 101 installed before the exhaust fan to remove paint mist generated during painting; Automatic temperature controller for painting temperature to keep the temperature in the winter booth constant by being electrically connected to the exhaust air return duct and return duct opening / closing damper 504 and a heater to recover the heat contained in the air in the winter booth. 103; In the drying operation, the air supply fan inlet damper 201 is closed in order to circulate and supply the dry air, and the open air damper 202 located in the dry air circulation duct is opened to operate the air supply fan (the exhaust fan is stopped). Work is performed while air is circulated, and the supply of dry heat is performed by heated high temperature hot air. A hot air supply fan 6 which sucks the volatile organic compound vapor generated during drying and blows the heated air of the heater 701 located in the catalytic combustion device into a high temperature hot air for drying and a high temperature hot air for desorption; A drying hot hot air supply pipe 902 and a hot air injector 9 for connecting the hot hot air heated by the heater to the dry air mixing chamber; A high temperature hot air flow control valve 901 for controlling a high temperature hot air flow rate in electrical connection with the drying temperature thermostat 102 installed to maintain the dry air temperature in the booth; A desorption hot hot air supply pipe 10 connected to send a part of the high temperature hot air heated by the heater to the adsorption tower for desorption of the activated carbon; A high temperature heat flow control valve shutoff timer 903 which closes the valve by sending an electrical signal to the high temperature hot air flow control valve for drying so as to be used for desorption of the heated hot air heated in the catalytic combustion device for a predetermined time during the initial operation; An adsorption tower outlet opening / closing damper 503 located at the stack to block inflow of outside air from the stack at the time of the suction of the hot air supply fan during the desorption; Low energy electric dry car paint booth, characterized in that configured to include.