Pump sealing options are largely influenced by long-standing industry conventions. Slurry pump manufacturers recommend expellers, mechanical packing, or single mechanical seals on slurry pumps. If you are looking for the best sealing, then you can check out expeller seal pump on https://www.schurcoslurry.com/slurry-pumps/severe-duty-slurry-pumps/s-series-lined-slurry-pump/.

Whenever any of these three arrangements are used to seal the process pumps in the mine’s scrubber and floatation circuits, the manufacturer requires a clean-water external water flush to be injected into the pump stuffing box.

Pump manufacturers specify the seal water to be injected at 10 psi above the discharge pressure of the pump. The water enters the volute casing in the stuffing box, directly behind the impeller. About one third (or more) of the flush water enters into the process stream because it is entering at a higher pressure.

The remaining two-thirds of the flush water leaks to the floor area surrounding the pump. If there is little outward leakage, a greater portion of the flush water enters the process fluid. This inward leakage dissolves the potash and reduces potash production yield, as outlined above.

Expellers force fluid back into the pump volute during operation. The expeller is limited by the pump inlet pressure. One manufacture recommends the maximum inlet pressure on a 1,500 GPM application should not exceed 9 psi to achieve leak-free performance. This means the expeller option is not suitable for high pressure tailings pumps, for example, and leads to the mechanical seal selection option.