Purging device in polypropylene production system

The utility model discloses a purging device in a polypropylene production system, which is characterized in that when the purging device is used, a polyacrylamide solution can be fed into a main cylinder through a liquid inlet pipe, a tooth-shaped scraper is moved to the leftmost end of the main cylinder at the moment, and an air blower is started after the main cylinder is filled with the solution; the air blown out by the air blower can blow away polyacrylamide formed on the upper surface of the solution and enable the polyacrylamide to move rightwards, the positive and negative rotation motor is started to control the screw to rotate and drive the tooth-shaped scraper to scrape the polyacrylamide formed on the surface rightwards, and finally the polyacrylamide formed on the surface flows out of the main cylinder through the water outlet. Meanwhile, gas blown out by the air blower can keep the surface of the liquid in an unstable state all the time, the liquid can be prevented from forming a film again, so