Pump Selection for Non-Viscous Liquids

Centrifugal pumps are widely used for fluid transfer. The type of impeller used significantly affects their performance with different fluid types.

Closed Impeller Suitability

For handling non-viscous liquids, oils, and chemicals, a closed type impeller centrifugal pump is generally preferred.

• Closed Impellers: These impellers have shrouds (top and bottom plates) that enclose the vanes. This design creates a more defined flow path.
• Efficiency: The enclosed design reduces internal leakage between the impeller and the pump casing, leading to higher efficiency, especially with low-viscosity fluids like oils and many chemicals.
• Chemical Resistance: The sealed nature helps contain the fluid and can be beneficial when handling corrosive chemicals, provided the pump materials are compatible.
• Smooth Flow: The smooth, confined passages minimize shear and turbulence, suitable for oils and chemicals where maintaining fluid integrity is important.

Comparison with Other Options

• Open type impeller: Better suited for liquids with solids or slurries, as the impeller is more exposed. Less efficient for non-viscous liquids due to leakage.
• Axial flow and Mixed flow pumps: These are typically used for high flow rate, low head applications and differ fundamentally in their mechanism compared to radial flow centrifugal pumps.

Therefore, the closed type impeller centrifugal pump is the most appropriate choice among the given options for the specified applications.