With the continuous improvement of industrial waste gas emission requirements, PP spray towers are gradually used in chemical industry, electroplating, pickling, electronics, mechanical processing and other industries. This equipment mainly uses spray absorption, filler contact and gas-liquid separation to pretreat or purify acid and alkali components, dust and some water-soluble pollutants in the exhaust gas.

1. Main uses of PP spray tower

PP spray tower is mainly used for the pretreatment of harmful waste gases, corrosive gases, dust-containing gases and some adhesive gases. By fully contacting the spray liquid with the exhaust gas, the concentration of particulate matter in the gas can be reduced, and some pollutants that are easily soluble in water or can react with the chemical liquid can be absorbed.

Depending on the exhaust gas composition and treatment requirements, the equipment can be used alone or in conjunction with activated carbon adsorption towers, biological deodorization equipment, mist eliminators or other exhaust gas treatment devices.

2. Main components of PP spray tower

PP spray tower usually consists of tower body, air inlet, air outlet, circulating water tank, circulating water pump, spray pipeline, nozzle, packing layer, liquid distributor, demister layer, maintenance port and sewage device.

1. Tower body: Often made of PP material, it has good acid and alkali resistance and corrosion resistance.

2. Spray system: Spray the absorbing liquid evenly into fine droplets to improve the gas-liquid contact efficiency.

3. Filling layer: Increase the air-liquid contact area to fully mix the exhaust gas and the absorption liquid.

4. Circulation system: The absorption liquid is recycled through the water tank and water pump.

5. Demist layer: removes water droplets entrained in the purified gas and reduces the discharge of liquid mist.

3. Working principle of PP spray tower

After the waste gas containing dust or acid and alkali components enters the tower body, it comes into contact with the absorption liquid sprayed from the nozzle. Pollutants are captured by the absorption liquid through collision, interception, dissolution or chemical reaction, thereby reducing the concentration of harmful components in the exhaust gas.

In the packing layer, the gas flow and liquid flow are further dispersed, the gas-liquid contact area increases, and the mass transfer process becomes more complete. After the purified gas passes through the demister layer to remove entrained droplets, it enters the subsequent treatment equipment or discharge pipe through the air outlet.

IV. Common gas-liquid flow forms

1. Counter-flow type: waste gas flows from bottom to top, and the absorption liquid is sprayed from top to bottom. The gas-liquid contact time is long and is a common structural form in spray towers.

2. Down-flow type: exhaust gas and absorption liquid flow in the same direction. The structure is relatively simple and can be used for partial cooling, humidification or preliminary washing conditions.

3. Cross-flow type: the exhaust gas flows horizontally and the absorbent is sprayed from top to bottom. It is suitable for horizontal scrubbers or situations where the installation height is limited.

Different gas-liquid flow forms have their own characteristics, and the equipment structure should be selected based on the treatment air volume, exhaust gas concentration, site conditions and emission requirements.

5. How to reduce equipment operation and maintenance costs

1. Carry out preventive maintenance: According to the equipment operating time, frequency of use and exhaust gas conditions, formulate plans for nozzle cleaning, packing inspection, water pump maintenance and circulating fluid replacement.

2. Strengthen status inspection: Through daily inspections, problems such as nozzle blockage, pipeline leakage, abnormal noise of water pumps, fan vibration and filler scaling can be discovered in a timely manner to avoid the expansion of minor faults.

3. Control the status of the circulating fluid: regularly detect the pH value, chemical concentration and sediment conditions of the circulating fluid, and replenish water, medicine or sewage in a timely manner.

4. Reasonable selection of equipment specifications: Spray towers, water pumps and fans should be selected based on actual air volume, lift, resistance and corrosiveness to avoid wasting energy consumption caused by too large equipment, or affecting the treatment effect due to too small equipment.

5. Reduce air flow short circuits: Reasonably arrange packing, nozzles and air flow distribution devices to allow waste gas to pass evenly through the tower body and improve equipment utilization.

6. Circulating water pump selection considerations

The circulating water pump should be selected based on the corrosiveness, temperature, solid particle content, circulation flow rate and system head of the absorbing liquid. For circulating fluids with strong acidity and alkalinity, priority can be given to corrosion-resistant engineering plastic pumps or other corrosion-resistant pump types suitable for working conditions.

The water pump installation form can be selected according to the water tank structure, site space and maintenance requirements: vertical pump in the tank, vertical pump outside the tank or horizontal corrosion-resistant pump. The specific configuration should not be based solely on motor power, but should be comprehensively determined based on actual operating parameters.

When the water pump is running, avoid idling due to lack of fluid, and regularly check the sealing status of the impeller, bearings, connecting parts and pipelines to reduce the risk of equipment damage and shutdown.

7. Equipment usage suggestions

The treatment effect of the PP spray tower not only depends on the equipment structure and material, but is also closely related to the spray fluid formula, circulating fluid management, air volume control and daily maintenance. Standardized operations and regular inspections will help maintain stable operation of the equipment and extend its service life.

In actual selection, the tower size, spray levels, filler height, water pump parameters and chemical type should be determined based on the exhaust gas composition, temperature, concentration, treatment air volume and emission requirements.