What is the advantage of the gear or lobes design in rotary pumps?

• A. It allows for higher energy efficiency
• B. It maintains a constant flow rate
• C. It creates suction by trapping liquid
• D. It reduces operational noise

Answer: (C)

The gear or lobes design in rotary pumps is especially effective because it operates by trapping liquid between the rotating elements, creating a vacuum that facilitates the movement of fluid through the system. This mechanism allows for efficient suction, drawing the liquid into the pump and subsequently displacing it to the discharge side.

This design is beneficial in a variety of applications where a gentle and consistent flow of fluid is required, as the trapping action ensures that the liquid is moved without significant turbulence. The ability to create a vacuum effectively makes this design an asset in managing fluids that could potentially be sensitive to shear or pressure changes.

Other designs may not harness the same trapping capability, which can lead to fluctuations in flow or may require more complex methods to achieve the necessary suction. While energy efficiency, flow rate consistency, and operational noise are important factors, the primary advantage of the gear or lobes design is its inherent function of creating suction by efficiently trapping the liquid.