Spray painting technology is widely used in industries such as machinery, electrical equipment, household appliances, automobiles, ships, furniture, etc. Spray paint raw materials - Coatings are composed of non-volatile matter and volatile matter. Non volatile matter includes film-forming substances and auxiliary film-forming substances, while volatile matter refers to solvents and diluents (mainly xylene). The organic gases in the spray paint exhaust come from the volatilization of solvents and diluents. Organic solvents will not adhere to the surface of the spray paint and will be completely released during the spray paint and curing process to form organic exhaust gas. The amount of xylene waste gas evaporated during the painting process accounts for about 30% of the diluent usage, and another 70% evaporates during the drying process.

1、 Principles of Process Design

1. Governance measures

The exhaust gas from paint spraying mainly consists of two parts: liquid paint mist and gaseous VOC. For liquid paint mist, a paint mist filter should be used, but for VOCs that are insoluble in water, a mature activated carbon filtration device should be used.

2、 Equipment features

1. Paint mist filter

The paint mist filter tower body is a cylindrical tower body wrapped with fiberglass as a whole, without segmented connecting flanges. The specific structure consists of a pressure chamber, a liquid storage tank, packing, a spray device, a foam removal device, etc. The structure of this purification tower adopts (1) saturated contact of exhaust gas directly entering water, with sufficient chemical reaction and high purification efficiency; (2) Adopting a new type of filler with a large specific surface area, high porosity, and uniform arrangement; (3) Adopting two absorption processes of spraying and bubbling, the absorption is sufficient and the purification effect is good.

2. Activated carbon filter

Activated carbon filters utilize the advantages of high-efficiency adsorbent materials (activated carbon fibers), such as strong adsorption capacity and fast adsorption and desorption rates, to purify organic waste gases. The exhaust gas from the outside of the tower is evenly distributed through the guide hood and sent into the tower. The incoming airflow passes through the adsorption bed of the tower's internal packing, and harmful chemical components in the airflow are adsorbed by the adsorbent. Clean air is discharged through the air outlet, and condensed water generated inside the tower is discharged outside the tower through the collection tank and discharge pipe.

3、 Technical parameters and selection

Due to different technical parameters such as gas concentration and temperature, this treatment equipment should be designed and selected according to actual conditions. Our company has a specialized design program that can design specific technical parameters that meet the standards according to the actual situation.

The design conditions that users need to provide include:

1. Provide a usable site for equipment operation;

2. Provide the amount and concentration of exhaust gas, temperature, and the standards required for treatment;

3. Provide whether the control mode is manual or automatic, and the degree of control achieved;

4. Provide us with the equipment and supporting facilities, pipelines, and accessories that we need to supply.