Components and characteristics of exhaust gas from electronic factory spraying process

The rapid development of the electronics industry has not only brought convenience to mankind, but also intensified environmental pollution. During the spraying process, organic waste gases such as toluene, xylene, and ethylbenzene will be produced.

Characteristics of exhaust gas from electronic factory painting operations

Characteristic 1: The main harmful substances include toluene, xylene, ethylbenzene, and butyl acetate. It is mainly used as a solvent or diluent for paints.

Feature 2: During the spraying process, the coating does not adhere to the surface of the product.

Characteristic 3: The concentration is generally between 100 and 500 mg/m3, but it has a high flow rate when used as a solvent. It is a typical example of an organic pollutant with low concentration and high flow rate.

Feature 4: Electronic products generate fine dust particles during the manufacturing process.

What are the methods for treating exhaust gas from the spraying process in an electronics factory?

Specifically, after the waste is sprayed, it first passes through an atomizing scrubber composed of multiple layers of porous fibers. The number of pores per unit area increases from the first layer. As the exhaust gas passes through the scrubber, fine particles, paint droplets and a small portion of organic matter in the exhaust gas constantly collide with the micropores and glue. The fine particles gradually become smaller and adhere together, eventually forming a complete bond.

The purified organic waste gas enters the adsorption chamber through the atomizer and the scrubber. Unlike ordinary activated carbon, the activated carbon adsorption chamber uses a new type of activated carbon clusters instead of channels, which have a larger surface area and more active adsorption sites. When low-concentration organic waste gas continuously passes through the activated carbon beam, substances such as toluene, xylene, and ethylbenzene are adsorbed onto the activated carbon, and the rest is discharged directly.

The active sites of the activated carbon in the adsorption chamber are occupied by organic waste, thus the activated carbon reaches a saturated state.

The organic substances are brought to the combustion chamber. The combustion chamber has multiple layers of catalytic combustion beds. The catalyst used in the catalytic combustion beds is made of precious metals such as palladium, which is widely used in the production of electronic products and is all made of metal catalysts. Because the production line of the electronics factory is easier to operate. It makes full use of the existing resources of the factory and reduces costs.

Organic waste gas is generated in a multi-layer catalytic bed. All the waste gas is burned to produce harmless carbon dioxide and water for the environment, as well as residual heat. The residual heat generated by the catalytic reaction is recovered and reused in the desorption chamber for further utilization. The desorption regeneration of the activated carbon enables the rational utilization of CO2 and H2O directly emitted into the entire spray waste gas.

The production characteristics of the electronics factory and the characteristics of waste gas emission have been fully considered. Combined with the actual production situation and process flow of the electronics factory. The existing resources of the electronics factory have been fully utilized. The entire process is interlocked, which can effectively handle waste gas and make full use of residual heat. This is feasible in the engineering design process. Moreover, it has high operational efficiency, low operating costs, and is in line with the concept of sustainable development.