What is slurry pumps
s described below, there are several types of pumps that are suitable for pumping slurries. However, we must address a couple of critical considerations before considering which technology to use.
- The size and nature of the solids in the liquid: the size and nature will affect the amount of physical wear on the pump and its components and if the solids will pass through the pump without being damaged.
A concern for centrifugal pumps is the speed and shear inside the pump may damage the slurry/solids. In general, twin screw pumps allow for the least damage to solids in a slurry.
- The corrosiveness of the liquid or slurry mixture: more corrosive slurries will wear pump components more quickly and may dictate the selection of the material from which the pump is constructed.
Pumps designed for pumping slurries will be heavier duty than those designed for less viscous liquids since slurries are heavy and difficult to pump.
Slurry pumps are typically larger in size than standard pumps, with more horsepower, and built with more rugged bearings and shafts. The most common type of slurry pump is the centrifugal pump. These pumps use a rotating impeller to move the slurry, similar to how a water-like liquid would move through a standard centrifugal pump.
Centrifugal pumps optimized for slurry pumping will generally feature the following in comparison to standard centrifugal pumps:
- Larger impellers made with more material. This is to compensate for wear caused by abrasive slurries.
- Fewer, thicker vanes on the impeller. This allows the passage of solids more readily — typically 2-5 vanes, compared to 5-9 vanes on a standard centrifugal pump.
For pumping abrasive slurries, these types of pumps may also be made from specialized high wear alloys such as AL-6XN® or Hastelloy® C-22®. Hardening stainless steel is also a common option for abrasive slurries, with Expanite and Armoly being two hardening processes.
For certain types of slurry pumping conditions, positive displacement pumps may be a more appropriate choice than a centrifugal-style pump.
