Page 181 - Centrifugal Pumps Design and Application

156 Centrifugal Pumps: Design and Application

Slurry Pipelines

It would seem appropriate when discussing pipeline pumps to comment
on future slurry pipeline operations. A review of existing slurry pipelines
shows the most common pumps are positive displacement (PD). These
are limited in capacity and normally operate up to 2,(XX) GPM with
larger pumps currently being developed to achieve 4,000 GPM. To ac-
commodate the high-capacity pipelines being planned with pipe size up to
42 in. and throughput rates of 500,000 BPD to 1,000,000 BPD, high-
capacity centrifugal pumps will be a viable alternative. As installation
costs and problems are directly related to the number of pumps required
for the service and as centrifugal pump efficiency increases with specific
speed, it is expected that centrifugals will become economically competi-
tive at capacities starting at 20,000 GPM (Figure 10-22). As slurry pipe-
line capacity increases, the benefits of large-capacity centrifugal pumps
operating in series as an alternative to multiple PD pumps operating in
parallel become obvious. It is reasonable to assume that the principles
and guidelines outlined in this chapter will be used on future slurry pipe-
lines,

Figure 10-22. Suggested economic range for centrifugal pumps in slurry pipe-
line applications.