Spray painting exhaust gas purifier is an "environmental barrier" in the automotive manufacturing, furniture painting, and metal surface treatment industries, specifically used to treat organic exhaust gases (such as VOCs such as benzene, esters, ketones, etc.) and paint mist particles (paint particles that are not attached to the workpiece) generated during the spray painting process. Its purification effect directly affects the air quality of the workshop and the surrounding environment, and regular calibration and scientific maintenance are key to ensuring the long-term efficient operation of the equipment. The following is a detailed explanation of the calibration method and daily maintenance skills for paint exhaust purifiers.

1、 Calibration method:

　　Spray paint exhaust purifierThe combination process of "filtration+adsorption/catalytic combustion" is usually used, and calibration needs to be adjusted for the core parameters of different modules:

Paint mist filtration module: The primary filter cotton (or honeycomb activated carbon filter) is used to intercept large particles of paint mist (diameter>5 μ m), and the calibration focuses on filtration efficiency (requirement>95%) and resistance (pressure difference<100Pa). Measure the concentration of particulate matter in the air before and after filtration using a dust particle counter (as per ISO 14644 standard). If the efficiency is insufficient (paint mist penetration rate>5%), replace the filter cotton (or clean the honeycomb activated carbon pores); Use a differential pressure gauge to monitor the pressure difference between the inlet and outlet (when it exceeds 150Pa, the filter module needs to be cleaned or replaced if it is clogged).

Adsorption module (activated carbon): used for adsorbing small molecule VOCs (such as toluene and xylene), the calibration key is the adsorption capacity (usually the adsorption capacity of activated carbon for VOCs is>100mg/g) and saturation state monitoring. Measure the concentration of VOCs at the inlet and outlet using a gas detector (such as benzene derivatives with an inlet concentration<500mg/m ³ and an outlet concentration<50mg/m ³). If the outlet concentration exceeds the standard (>100mg/m ³), it indicates that the activated carbon is close to saturation (requiring regeneration or replacement); Use the weighing method (regularly taking out a small amount of activated carbon to measure weight gain, and the mass increases after adsorbing VOCs) to assist in determining the saturation level (weight gain>20% needs to be treated).

Catalytic combustion module (if available): VOCs are decomposed into CO ₂ and H ₂ O at 200-400 ℃ using precious metal catalysts such as platinum and palladium. Calibration focuses on catalytic temperature (catalyst ignition temperature<250 ℃), airspeed (gas flow rate through the catalyst layer, typically 3000-10000 h ⁻¹), and conversion rate (requirement>95%). Use an infrared thermometer to monitor the temperature of the catalyst bed (if the deviation is>± 20 ℃, adjust the heating power), and use a gas analyzer to detect the concentration of VOCs at the inlet and outlet (when the conversion rate is insufficient, check whether the catalyst is poisoned (such as sulfur or phosphorus compounds covering the active sites) or aged (after more than 3 years of use)).

2、 Daily maintenance skills:

• Filter module maintenance: The initial filter cotton should be checked every 1-2 weeks (in workshops with high spray paint volume) or 3-4 weeks (low load). If there is obvious accumulation of paint mist on the surface (darkening color, decreased breathability), compressed air (0.2-0.3MPa) should be used to blow in the opposite direction (clean surface particles). If it is damaged or blocked severely (pressure difference>150Pa), it should be replaced; Honeycomb activated carbon filters should be checked every 3-6 months (based on VOCs concentration). If the adsorption capacity decreases (outlet concentration increases), use hot nitrogen gas (120-150 ℃) to blow and regenerate (restore partial activity), or directly replace the filter element with a new one.

• Adsorption/catalytic module maintenance: The activated carbon adsorption bed should be checked every six months. If the activated carbon particles are found to be broken (affecting the uniformity of the airflow), they should be screened with a sieve and refilled; The catalyst of the catalytic combustion module is tested every 2-3 years (or when the conversion rate significantly decreases). If it is poisoned (such as detecting sulfur content>10ppm), the catalyst carrier is soaked in dilute sulfuric acid (1%) solution (to remove sulfides), and then calcined at high temperature (400 ℃, 3 hours) to restore activity; Regularly clean the carbon deposits on the catalytic bed layer (using a vacuum cleaner to remove surface dust).

• Overall equipment inspection: Check the operating current of the fan (such as a centrifugal fan) every week (if the deviation is greater than ± 10%, check for impeller wear or bearing faults), and the tension of the belt (press the belt with your fingers, and a sinking of 10-15mm is normal, too loose will cause a decrease in speed); Monthly inspection of pipeline sealing (using soapy water to test the interface, with no bubbles considered qualified) to avoid air leakage and reduce purification efficiency; Clean the accumulated paint inside the equipment every quarter (gently brush with a soft bristled brush, avoid scratching with steel wire balls) to prevent paint residue from blocking the airflow channel.

　　Spray paint exhaust purifierCalibration and maintenance are a combination of science and experience. By precisely adjusting core parameters (filtration efficiency, adsorption capacity, catalytic temperature) and scientific daily operations (filter cotton replacement, activated carbon regeneration, catalyst detection), not only can the equipment ensure long-term stable operation (purification efficiency>95%), but it can also provide solid guarantees for occupational health and environmental protection in the paint spraying workshop, which is an important skill for enterprises to practice green production.