Page 253 - Centrifugal Pumps Design and Application

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Slurry Pumps
by George Wilson
Goulds Pumps, Inc.

There are various types of centrifugal slurry pumps, which are identi-
fied by their capability to handle solids ranging in size, hardness, concen-
tration, and velocity. An understanding of these important factors will
lead to an optimum choice of pump design where the materials of con-
struction and rotational speed are ideally matched to the process system,

Slurry Abrasivity

The abrasiveness of slurries is difficult to define due to the number of
variables involved. It is dependent on the nature of the slurry being
pumped and the materials of construction of the pump liquid end compo-
nents.
Wear increases with increasing particle size. For example, the rate of
erosion wear when pumping a silica sand slurry is approximately propor-
tional to the average particle size raised to the power of 1.4.
Wear increases with concentration; the relationship is linear up to about
10% by volume. At higher concentrations, the rate of wear will level out
due to the cushioning effect of the particles as they collide.
Wear increases rapidly when the particle hardness exceeds that of the
metal surface being abraded. The effective wear resistance of a metal
will depend on the relative hardness of the metal to that of the particle.

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