In what type of pump is the movement of liquid controlled by closely meshed vanes?

The type of pump where the movement of liquid is controlled by closely meshed vanes is a rotary pump. In a rotary pump, the vanes are designed to fit snugly into a circular chamber, where their movement creates a vacuum that draws liquid into the pump and subsequently pushes it out. The close meshing of the vanes allows for a more efficient transfer of fluid as it minimizes any potential backflow and maintains a consistent flow rate.

This design is particularly effective because it can handle various viscosities of liquids and is often used in applications requiring a steady and controlled flow. Rotary pumps are widely utilized in various industries for their reliability and versatility, including in water treatment processes where maintaining precise flow rates is crucial for operational efficiency and safety.

The other pump types mentioned have different operational mechanisms. For example, diaphragm pumps primarily use a flexible diaphragm to create suction and displacement, while piston pumps utilize a reciprocating mechanism to move liquid through chambers. Pneumatic pumps function using compressed air to move fluids, rather than being directly dependent on the interaction of closely meshed components like a rotary pump. Each of these pumps has its specific applications and benefits, but the characteristic of closely meshed vanes distinctly defines the operation of rotary pumps.