Pumps performance, specific gravity

FIG. 10-31 Typical pump performance curve. The curve is shown for water at 85 F. If the specific gravity of the fluid is other than unity, BHP must he corrected. 

Debris particles that are heavier than water migrate to the outer wall area and slither down into a collection bowl that is periodically blown down. Very little water is lost. Typical performance is 97.8% of solids with specific gravity exceeding 1.2 down to 45 microns. Side stream filtration is more common in cooling tower applications. The scheme uses a small dedicated pump to draw dirty water from the sump, direct it through a filtration device and sent it back to the basin. 

To perform experiments at a constant pressure, a flow-type supercritical biomass conversion system was used. Major sections of the flow-type system consisted of pump stations, preheaters, supercritical treatment tube, cooling system, and separatory tank. The reaction time was calculated by dividing the volume of the treatment tube by the volumetric flow rate at the given conditions. Knowledge of the thermodynamic properties of the solvent, particularly correlation among temperature, pressure, and specific gravity, is important in order to accurately calculate the reaction treatment. Detailed information of the treatment with this equipment can... 

System performance and power requirement are therefore normally graphically presented and calculated in the same way as for clear liquids. Subject to some minor corrections, a centrifugal pump will pump the same volumetric flowrate of slurry as for water through a given flow system. The pump discharge pressure and its power draw will be increased in proportion to the slurry specific gravity, as for any clear fluid of increased density. 

Heavy metal oxide slurry is to be pumped at a volumeUic concentration of 18%. The specific gravity of the solids is 5.0 and the rfso is 400 pim. The calculated head on slurry is 35 m. Determine the head ratio and the equivalent water head on the pump performance curve. 

Burgess, K. E. and ). A. Reizes. 1976. The effect of sizing, specific gravity and concentration on the performance of centrifugal slurry pumps. Proc. Inst Mech. Eng., 190, 36. 

In the present study, experiments were conducted to determine the individual effects of solid properties (particle size, solids specific gravity) and solids concentration by weight, as well as tip clearance effects on an open impeller centrifugal pump characteristics. Tip clearance is varied from 1.25 mm to 8 mm over the experiments and maximum particle size was approximately 2.4 mm. Test results have shown that, slurry characteristics and running tip clearance have a considerable impact on the pump performance. These effects, therefore, must be taken into account for piunp design considerations and selection. 

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