Project Design and Construction Scheme of Automobile Spray/Bake Booth

Project Design and Construction Scheme of Automobile Spray/Bake Booth

Exhaust Gas Emission Pollution Control (Activated carbon and light oxygen treatment)



Tel:  020-86378972

Fax:  020-86569629

Contact person: Jimmy.Wu

Pollution Control Scheme of Exhaust Gas Emission from Automobile Spray/Bake Booth

Part One Pofile

The mainly pollution in the work process of car spraying/baking is:Volatile Organic Compounds (VOC) produced in the process of painting

The car spray bake room is a fully enclosed type of equipment,  and are mainly used for the outside  damage of cars. Its working time is intermittent.Exhaust emissions time after work is less than 1

hour, the gas displacement is generally 18000m3 / h, the main pollutants are benzene, toluene, xylene.

According to the requirements of the “car spray paint room” (the People’s Republic of China Transport Industry Standards, JT / T324 / 2008), benzenes and other gas emissions of the car spray bake room should be consistent with the “Integrated Emission Standards for Air Pollutants”(the People’s Republic of China National Standard GB16297-1996),the emission requirements are shown in Table 1.

Table 1: “Integrated Emission Standards for Air Pollutants” Benzene Emission Concentration Limits (New sources of pollution)

Pollutant name Benzene Toluene xylene
Maximum allowable discharge concentration (mg / m3) 12 40 70

※ This form applies to enterprises established after January 1, 1997.

Part Two :Treatment of Spray/Bake Booth Organic Waste Gas

First, The design basis, principles, scope and objectives

1.1 Design Basis

1.1.1 “Car Spray Bake room” (People’s Republic of China Transport Industry Standard JT / T324-2008)

1.1.2 “Integrated Emission Standard for Air Pollutants” GB16297-1996

1.2 Design Principles

1.2.1 Reliable, flexible, health, energy saving, low costs of integrated operating,Easy operation and management, save investment, and can ensure long-term stable operation principle.

1.2.2 Electrical semi-automatic control as much as possible to reduce the labor intensity of workers.

1.2.3To ensure that discharge standards,and not to produce secondary pollution.

1.3 Design Scope

1.3.1 Selection and design of process flow

1.3.2 Non-standard equipment manufacturing and standard equipment selection;

1.3.3 Installation and commissioning of engineering equipment;

1.3.4 Electrical design and construction

1.4 Design Goals

On the basis of the function of the existing spray booth, after treating the organic pollutants produced by each pollution sources,they will meet the national standard “Integrated Emission Standard for Air Pollutants” GB16297-1996 and the local standard “Air Pollutant Emission Limits”.

The maximum allowable discharge concentration for the second period.

Benzene: <12mg / m3

Toluene: <40 mg / m3

Xylene: <70 mg / m3

Second ,The amount of waste gas and pollutant concentration

2.1 The amount of waste gas

According to the current standard paint room, the total discharge of waste gas during work is about

18000m3 / h.

2.2 Emissions of organic pollutants

According to the relevant practice data, we initially determine the concentration of pollutants in the waste gas is roughly:

Benzene: 25mg / m3

Toluene: 100 mg / m3

Xylene: 150mg / m3

Third, the treatment process selection and description

3.1 Selection of treatment process

The main pollutants in the painting and baking process are the organic gases produced by the organic solvents and diluents in the paint.

According to our company experience in dealing with painting exhausting gas, the most effective methods are the adsorption and light

Oxygen-catalyzed comprehensive management. Taking into account the various factors, especially the actual situation of maintenance factories, our company find out the following measurements:

Dry filter + activated carbon adsorption + light oxygen catalyst:

First:Dry filter

Second:activated carbon adsorption

Third:light oxygen catalyst

(1)Dry filter:

Gas containing dust and a small amount of easily adhesive material,  dry filter device will filtrate these duct and material.

(2) Activated carbon adsorption:

The benzene in organic waste gas is purified by activated carbon adsorption.

Activated carbon with multi-layers drawer structure, it is suitable for high flow with  low concentration of organic waste gas adsorption.

TF efficient activated carbon adsorb goes up to 500-1500 ㎡ / g;

Larger surface area has a high surface activity and adsorption capacity.

The discharged low concentration of organic gas is adsorbed on its active surface for purification purposes

(3)Light oxygen catalyst

The molecular chain of volatile harmful emissions is purified by an ultraviolet light source.

First, use 253.7 nm light cutting, breaking chain, burning, cracking exhaust gas chain to change the molecular structure;

Second, take the 185-nanometer light on the exhaust gas to catalyst and oxidation, connecting the destruction of molecules or neutrons, atoms to O3 ,so that organic or inorganic macromolecule chain of odor compounds change into low molecular weight compounds CO2, H2O, etc .in the catalytic oxidation process;

Third, according to different waste gas composition of , especially more than 7 kinds,  corresponding inert catalyst, The catalyst uses honeycomb metal mesh as carrier, all contact with the light source, inert catalyst will occur catalytic reaction below 338 nm light source, amplification 10-30 times the light source effect, so that it can be sufficient response with exhaust gas, which will shorten the exposure time of the exhaust gas and light source, improving the exhaust gas purification efficiency. The catalyst also has a similar function like photosynthesis to purify the exhaust gas.

Finally, with triple-treated exhaust gas is vented into the atmosphere through fan.

3.2 Technical Process:

3.3 Process description

The exhaust gas passes through the cotton filter, the air inlet M-type filter filter and the adsorption tower inner glass

Glass fiber cotton filter, into the activated carbon adsorption tower for adsorption, and then into the light oxygen reminder

The reaction tank for catalytic treatment, and finally by the fan to the outdoor, organic emissions

Meet or exceed the national standard requirements.

Note: activated carbon adsorption can be saturated in the activated carbon adsorption bed regeneration (regeneration equipment needs

Optional) or replaced.

3.4  Plan. layout and physical map

3.4.1 Layout of exhaust gas treatment device and air drawing device

3.4.2 Layout of exhaust gas treatment equipment

Fourth, the design parameters

4.1 pipe diameter of the duct

Take the wind speed in the main duct 10m / s

S = Q / V = 18000m3 / h ÷ (3600s / h × 10m / s) = 0.5 ㎡

Duct size : 740 × 740 (mm).

4.2 Activated carbon filter device

Using multi-layer drawer design, to increase the filter area, reduce the wind resistance and wind speed, which is easily to replace the filter.  Filter gas speed of 1.2m / s, filter area of 18000÷ (3600 × 1.2) = 4.17 ㎡.  single drawer filter size :1225 × 500 × 1009(mm),  total 7 layer drawer.

4.2.1 The advantages and replacement or clear cycle of filter and adsorption material

  • Purification rate;
  • Flame retardant, do not need to worry about dust explosion and catch fire;
  • Low resistance; material can be used recycling many times ;
  • Using simply, convenient and easy to maintain
  • No corrosion, no secondary pollution, low operating cost
  • Replacement or clear cycle: every 20 sets cars replace filter, every 200 sets cars replace activated carbon

Specific parameters selected of the activated carbon adsorption device  Choose the high quality activated carbon

Activated carbon have large ratio of surface area, microporous structure, high capacity, high surface activated carbon products widely used in the fields of controlling pollution, select activated carbon adsorption method, the waste gas meet the large surface and porosity of activated carbon, the pollutions in the exhaust gas  is adsorption, make its separation from gas mixture and purification effect.

Iodine adsorption valve  900mg/g      adsorption rate: η≥30%

Packing density: 600g/L     Surface rate: 1000m2/g Activated carbon saturation period

According to the experience, the saturation period of activated carbon is every 200 cars or total 200 hours for painting operation The volume of activated carbon in the activated carbon adsorption device

The activated carbon device have 7 layer

The volume of activated carbon: (1225×500×100)×7 layer=0.429(m3)

4.3 Light oxygen catalytic device

Light oxygen catalytic device use Uv light source and more than 7 kinds inert corresponding catalyst, using honeycomb metal mesh as catalyst carriers, the catalytic processing device have three layer and four interval structure,

The catalytic processing device power:  3.5KW ( not include fan power)

Light oxygen catalytic device no need artificial maintenance, but have to clear on schedule and replace dry filter

4.4 The calculation of system resistance

According to the calculation and practical experience: the resistance loss of duct、 dry filter device、 activated carbon adsorption device and light oxygen catalytic device is about 800pa.

4.5 Wind centrifugal fan selection

The wind flow is about 18000m3/h when spray booth working, but the duct and relevant device will add resistance, so the spray booth must be equipped fan device which is equal to air volumes to meet spray booth operating requirement. According to the work requirement of spray booth, through the theoretical calculation and empirical collection, the fan flow: 20000m3/h, the fan pressure head choose 800pa

五、A set 18000m3/h emissions of environmental protection facilities offer

Dry filter+ activated carbon adsorption+ UV light oxygen catalytic price sheet

No      Item     Spec(m)      Unit price(RMB/SET)            Amount

1 Dry filter

2 Activated carbon adsorption device

3 UV light oxygen catalytic device

4 Fan and Fan frame

5 Fan duct and fasteners

6 Electric control

7 Installation accessories and activated carbon material

8 Replacement floor filter

9 Replacement air door filter

10 Maintenance

11 Transportation

12 Installation

13 Tax


六、The operating cost every facilities

The main operating cost of equipment is electric charge and artificial cost

First confirm the operating system: arrange 1 person to operate

6.1 Artificial: part-time (operating the spray booth simultaneously)

6.2Electric charge: fan operation rate: 80%   Total 14.5 KW, 1.0 RMB per KWH, the electric charge is 0.8×14.5×1.0=11.6 RMB/H

七、The project schedule

The early stage of the plan and organization    7 working days

7.2 Equipment installation:  2 working days

7.3 System test

1 working day, total 10 working days (not include the transportation time)


(1)During the period of construction, in case of special circumstances or force majeure, affect the normal construction, the working time postpone

(2)The environmental governance project does not include unplanned extension part of the pipeline, such as extensions to lengthen, to be agreed upon between the charges.

PART THREE  Appendix

Spray Booth 《Organic Waste Gas Emission Monitoring Analysis Report》


April 20, 2017

This entry was posted in Automotive Paint Spray Booths and tagged , , . Bookmark the permalink.

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