Discover What¡¯s Inside a Submerged Pump
Slurry pumps feature relatively wide flow passages to accommodate the passage of large particles, ensuring strong flow capacity. The wetted parts have thicker walls for extended service life. The impeller typically uses cylindrical blades and is designed with front and back shroud blades to reduce leakage and balance axial forces. For pumps handling highly abrasive slurries, the impeller outlet and volute outlet section are designed with inwardly curved arc exits to account for slurry flow characteristics.
The impeller is a key component of a submerged pump. Based on mechanical structure, impellers can be classified into three types: closed, semi-open, and open. Closed impellers are suitable for conveying clean liquids, while semi-open and open impellers are used for suspensions containing solid particles, though these types generally have lower efficiency. According to the suction method, impellers are divided into single-suction and double-suction types. A single-suction impeller has a simple structure with liquid entering from one side only. A double-suction impeller draws liquid symmetrically from both sides simultaneously, offering greater suction capacity and essentially eliminating axial thrust.
The shaft seal assembly is necessary because the pump shaft rotates while the pump casing remains stationary, inevitably creating a gap between them. To prevent high-pressure liquid inside the pump from leaking out through this gap, or to prevent outside air from entering the pump in the opposite direction, a shaft seal must be installed. Submerged pumps commonly use two types of shaft seals: packing glands and mechanical (face) seals. A packing gland forms a seal ring in the annular gap where the shaft passes through the casing, packed with soft sealing material. A mechanical seal consists of a rotating ring mounted on the shaft and a stationary ring fixed to the casing; the two ring faces are pressed together by spring force and rotate relative to each other, achieving an effective seal.