The shut-off fan is used at the discharge port of the unloader that operates under negative pressure. The upper part receives the material discharged by the shut-off fan and relies on the rotating impeller to transport the material, while also serving as a seal to prevent air from being sucked in from the discharge port during pneumatic conveying, ensuring the normal discharge of the shut-off fan. As a discharge equipment, it plays a significant role in cleaning and cleaning work. The shutdown fan is the main equipment for dust removal, ash discharge, air supply, and other equipment feeding. The shutdown fan is suitable for powdered and granular materials. Widely applied in industrial sectors such as environmental protection, metallurgy, chemical industry, grain, and food.