High-pressure discharge online cleaning device system and process applied to SPG polypropylene process

The invention discloses a high-pressure discharge online cleaning device system applied to an SPG polypropylene process. The system comprises a high-pressure discharge tank and a powder recovery tank, wherein the high-pressure discharge tank is provided with a feeding pipe for introducing polypropylene slurry, the bottom outlet of the high-pressure discharge tank is connected with the top inlet of the powder recovery tank through a discharge valve by a pipeline, the bottom of the high-pressure discharge tank is also connected with a CO pipeline, the bottom of the powder recovery tank is connected with a gas replacement pipeline, a gas outlet in the top of the powder recovery tank is connected to a torch through a propylene discharge pipeline, control valves are arranged on the corresponding pipelines, and a first pressure gauge and a second pressure gauge are arranged on the high-pressure relief tank and the powder recovery tank respectively. According to the invention, by means of the device system, online c