Impeller single suction

Fig. 16. Gaps A (between impeller shrouds and diffusor wall) and B (between impeller and diffusor vane tips) corrective option where D = diameter and is diameter reduction (a) overall diameter reduction (b) vane diameter reduction (c) angle-cut, single-suction impeller and (d) angle-cut,...

Howe er, most conventional pump impellers receive the fluid into the impeller eye, at the center or inside diameter of the impeller. There are single suction impellers, and dual or double suction impellers with two eyes, one on each side. Dual suction impellers are mostly specified for low NPSH applications because the eye area is doubled (it ean reeeive twice as much fluid at a lower velocity head). Dual suction impellers arc mostly found on split case pumps where the shaft passes completely through the impeller. But they can afso be found mounted onto the end of the shaft in some special pump designs. 

Dual Suction Impeller, Single Stage, NFPA Code/ Firewater... 

VALUES OF SPECIFIC SPEEDS SINGLE SUCTION IMPELLER... 

Enclosed single-suction impeller with sealing on suction and back sides. (Courtesy The Deming Co.)... 

Coarse abrasives Single suction. Not available for full range of ratings, that is, small capacities not too easily obtained. Often have very large impellers operated at slow speeds for use when solids larger than 1" diameter are the standard diet. This would be of the type called dredge pumps handling sizeable rocks. Closed. 

Pulpy solids such as paper stock Single suction. Double suction only used on very slight solids concentrations and then with special end clearance wearing fits. Closed. Open type used to be standard but change to end clearance wearing fits made closed impellers better suited. 

Figure 3-48. Upper limits of specific speeds for single suction overhung impeller pumps handling dear water at 85°F at sea level. (By permission, Hydraulic Institute Standards for Centrifugal, Rotary, and Reciprocating Pumps, Hydrauiic Institute, 13th ed., 1975.)...

Pump impellers are further classified as to the inlet flow arrangement such as single suction (which has a single inlet on one side) and double suction (which has a double inlet on each side of the impeller). 

SPECIFIC SPEED, N. = RPM VGFM FOR SINGLE SUCTION OVERHUNG IMPELLER PUMPS... 

Straight-vane, single-suction closed impeller. (Worthington Pump, Inc.)... 

Figure 7.3. Performance curves of single-suction impellers corresponding to two values of the specific speed, (a) Ns - 1550, centrifugal pump, (b) Ns = 10,000, mixed and axial flow pumps.

Figure 7.9. Some types of centrifugal pumps, (a) Single-stage, single suction volute pump, (b) Flow path in a volute pump, (c) Double suction for minimizing axial thrust, (d) Horizontally split casing for ease of maintenance, (e) Diffuser pump vanes V are fixed, impellers P rotate, (f) A related type, Ihe turbine pump.

Single suction the liquid enters on one side at the eye of the impeller most pumps are of this lower cost style [Fig. 7.2(c)],... 

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