Knowledge about sewage pump impellers’ categories

Sewage pump categories

Sewage pump can be divided into under fluids sewage pump, inline sewage pump, submersible sewage pump, vertical sewage pump, anti-corrosive sewage pump, acid-resisting sewage pump and self-prime sewage pump.

Sewage pump is a kind of non-clog pump. Same as other pumps, impellers and pumping chamber are two main parts of sewage pump. The quality of these two parts represents the quality of the pump. The anti-clog performance, efficiency, anti-cavitation performance and anti-resistance performance of sewage pump are primarily decided by its impellers and pumping chamber. Sewage pump is mainly used to deliver fluids containing fibers, paper scraps, solid particles and other suspending solid materials, widely used in environmental protection industry, municipal projects, water conservancy projects, sewage treatment projects and other industries. The structure of impellers is of great importance to the anti-clog performance of sewage pump. Impellers have four different structures: blade type (open or closed), rotational flow type, flow channel type (single channel or dual channel), spiral centrifugal type.

Rotational flow type impeller

A pump with this type of impeller will have good anti-clogging performance, as the impellers are almost all kept away from the flow channel in pumping chamber. It can let solid particles and long fibers pass through much easier. The solid particles depend on the drive of whirlpool generated by rotating impellers to flow in pumping chamber. Suspending solid particles does not generate energy by itself. They only acquire energy from fluids in flow channel. When flowing, the suspending particles and long fibers don’t contact with the blades, so the blades won’t wear severely and the situation that clearance is enlarged because of wearing won’t happen. Its efficiency will not drop down sharply when it runs for a long time. Pumps with this type of impellers are suitable to pump fluids containing large particles and long fibers.

From the view of performance, this impeller has low efficiency, only about 70% of common closed impellers. Its lift curve is relatively flat.