Vertical turbine pumps and motors
Vertical turbine pumps were chosen for this application based on a desire to
alleviate problems with priming and air entrainment. These problems are
completely eliminated since, by definition, the impeller on a vertical turbine
pump is located below the mean water level.
Figure 16 provides an oblique view of the 20 vertical turbine pumps, drive
motors, and discharge pipes immediately after the installation was complete.
Each vertical turbine pump consists of a single-stage impeller and bowl
assembly, a vertical column assembly, a discharge head, and an electric drive
motor. Closed-type Francis-Vane impellers were used to eliminate the
requirement of having to adjust the clearance beneath the impellers to maintain
optimum hydraulic efficiency. The impellers are constructed of high-strength
silicon bronze and the suction bowls have vitra glass-lined waterways for
maximize abrasion resistance. Minimizing long-term abrasion in the pumps was
an important design criterion, because it was anticipated that small quantities of
sand would pass through the systems during moveable-bed experiments.
Figure 16. Oblique view of 20 vertical turbine pumps and motors
Longshore Current Recirculation System