The working principle of the spray tower is mainly based on the contact and chemical reaction between liquid and gas, and the waste gas is purified through spraying, adsorption and neutralization reactions. The spray tower disperses the liquid into fine droplets through the nozzle. These droplets form a layer of water film in the process of mixing with the air flow, which absorbs and removes harmful substances in the waste gas. In addition, the spray tower is equipped with fillers inside, which further absorb and filter tiny particles and harmful substances in the waste gas. Finally, a water collector is set at the bottom of the spray tower to collect the treated wastewater.