Quantitative dosing device and gas purification system comprising same

The utility model provides a quantitative dosing device which comprises a cylinder body, a dosing device and a dosing device, wherein an accommodating cavity for accommodating alkali liquor is formed in the cylinder body; an outlet of the liquid inlet pipe is communicated with the accommodating cavity; an inlet of the liquid outlet pipe is communicated with the accommodating cavity; the overflow pipe is communicated with the containing cavity, and an inlet of the overflow pipe is formed in the position, at the set height, in the containing cavity. The alkali adding device adopting the structure can ensure that the pressure at the inlet of the liquid outlet pipe is stable, so that the flow speed of alkali liquor in the liquid outlet pipe is constant, the alkali adding is stable, and meanwhile, the alkali adding device also has the advantages of simple structure, convenience in processing and manufacturing and low cost. 本实用新型提供一种定量加药装置，包括：筒体，所述筒体内设置有用于容纳碱液的容纳腔；进液管，所述进液管的出口连通于容纳腔；出液管，所述出液管的入口连通容纳腔；溢流管，所述溢流管连通容纳腔