Page 46 - Centrifugal Pumps 2E

32 Centrifugal Pumps: Design and Application

Figure 3*5. Impeller eye diameter/outside diameter ratio.

Step 5: Determine eye diameter,
From Figure 3-5:

D,/D 2 = .47
D, = 11.66 X .47 = 5.5 in.

Step 6: Determine shaft diameter under impeller eye.

Methods for calculating shaft diameter are discussed in detail under
shaft design. For this exercise, the shaft diameter under the impeller
eye is assumed to be 2 in.

Step 7: Estimate impeller eye area.

Eye area = Area at impeller eye — shaft area

= 23.76 - 3.1 = 20.66 sq in.