Slurry Pump: What is it, and how does it work

08 Sep.,2022

 

high pressure slurry pump

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.

    These conditions include:

    • A low slurry flow rate
    • A high head (i.e., the height to which the pump can move liquid)
    • A desire for greater efficiency than that afforded by centrifugal pumps
    • Improved flow control

    Common types of positive displacement pumps used in slurry pumping applications include:


    Rotary Lobe pumps

    These pumps use two meshing lobes rotating within a pump's housing to move fluids from the pump's inlet to its outlet.


      Twin-screw pumps

      These pumps employ rotating screws to move liquids and solids from one end of the pump to another. The screws' turning action creates a spinning motion that pumps material.


        Diaphragm pumps

        These pumps use a flexible membrane that expands the volume of the pumping chamber, bringing in fluid from an inlet valve and then discharging it through an outlet valve.


        Selecting and operating a slurry pump

        Choosing the right pump for your slurry application can be a complex task due to the balance of many factors including flow, pressure, viscosity, abrasiveness, particle size, and particle type. An applications engineer, who knows how to take all of these factors into account, can be a great help in navigating the many pump options available.

        ~ Matthew Sato, Applied Products Sales Manager, Ampco Pumps

        In determining which type of slurry pump is best suited for your particular application, follow these four simple steps.