Flocculating agent adding device

The utility model discloses a flocculating agent adding device. The powder spraying device comprises a sewage tank, a feeding pipe, a powder spraying head, a vertical pipe, a pneumatic conveying bin,a discharging hopper, a star-shaped discharging valve and an air pump. High-speed airflow is pumped into the bottom of the pneumatic conveying bin from the air inlet through an air pump; the flocculating agent transferred to the bottom of the pneumatic conveying bin is taken up; the air flow is pumped out from the air outlet; high-pressure air flow which is pumped out from an air outlet of the pneumatic conveying bin and contains flocculating agent powder is pumped into the feeding pipe through a vertical pipe; powder is sprayed out dispersedly through a powder spraying head at the bottom of the feeding pipe; according to the sewage treatment device, the flocculating agent is uniformly sprayed into sewage, stirred and mixed through airflow, dispersed through airflow and uniformly sprayed into the sewage, the sewag