The treatment principle of the spray tower: Acid mist waste gas is introduced into the purification tower through the air duct, where it comes into full contact with the absorbent sodium hydride and the gas and liquid after passing through the filling layer, to absorb and neutralize the gas. After purification, the acid mist waste gas is dehydrated through the dust board and then discharged into the atmosphere by the fan. The absorbent is sprayed from the top of the tower after being pressurized by the pump at the bottom, and then recirculated back to the bottom. The purified acid mist waste gas meets the emission standards.