Chopping Away At Solids

By Glenn Dorsch and Kent Keeran, Vaughan Company Inc., Washington, U.S.A.

Chopper pumps utilize a chopping action between the impeller and the suction plate to break down solids that pass through the pump into smaller pieces. Vaughan Company, an established pump manufacturer in Washington, U.S.A., designs and manufactures a line of centrifugal chopper pumps.

These pumps originally were designed in the 1960s for use in the local dairy industry to transport manure to and from storage tanks. Since then, Vaughan chopper pumps have been refined continually and awarded a number of patents; the company has earned wide acceptance for many applications that require solids handling. Today, Vaughan chopper pumps are used in various phases of municipal and industrial sewage treatment, food processing, and pulp and paper industries, in which the pumped liquid contains solids that need to pass through the pump without clogging or plugging.

The benefit of a Vaughan chopper pump over a typical non-clog or slurry pump is that it reduces the solids size of material passing through the pump. The unique chopping requirements and suction arrangement of these pumps make it difficult to apply standard impeller design practices in order to evaluate hydraulic performance. As energy costs continue to rise, developing more efficient pumps becomes increasingly critical for all pump manufacturers. Vaughan Company found that simulation was an effective and efficient way to approach the optimization of pump design.