The filling layer in the spray tower serves as a mass transfer device for the gas-liquid two-phase contact member. The bottom of the packing column is equipped with a packing support plate, and the packing is placed on the supporting plate in a random manner. The top of the packing is fitted with a packing pressure plate to prevent it from being blown by the updraft. The spray from the top of the tower is sprayed on the filler by a liquid distributor and flows down the filler surface. The gas is sent from the bottom of the tower and distributed by the gas distribution device. After the gas distribution device is distributed, the liquid continuously passes through the gap of the packing layer in a countercurrent manner. On the surface of the filling, the gas and liquid are in close contact with each other for mass transfer. When the liquid flows down along the packing layer, wall flow sometimes occurs. The wall flow effect causes the gas and liquid phases to be unevenly distributed in the packing layer, thereby reducing the mass transfer efficiency. Therefore, the packing layer in the spray tower is divided into two sections, and a redistribution device is set in the middle. After redistribution, it is sprayed on the lower packing.
The exhaust gas is introduced into the purification tower by the air duct. After passing through the packing layer, the exhaust gas and the sodium hydroxide absorption liquid are fully contacted and absorbed by the air and liquid. After the acid mist exhaust gas is purified, it is dehydrated and removed by the fog removal board and discharged by the fan into the atmosphere.. The absorbent is pumped at the bottom of the tower and sprayed on the top of the tower before returning to the bottom of the tower for recycling.