What is water ring vacuum pump?

A water ring vacuum pump, also known as a liquid ring vacuum pump, is a type of positive displacement pump that uses a liquid (typically water) to create a vacuum. It works by rotating an impeller eccentrically within a cylindrical casing partially filled with liquid, creating a rotating “liquid ring” that traps and compresses gases or vapors. This liquid ring acts as a sealant, preventing gas leakage and ensuring efficient pumping action.

This video demonstrates the working principle of a liquid ring vacuum pump, showing how the impeller and liquid ring create a vacuum:

Here’s a more detailed explanation:

Structure:
The pump consists of a cylindrical casing, an impeller with vanes, and a liquid (usually water).
Working Principle:
The impeller is positioned off-center within the casing. When the impeller rotates, the liquid is forced against the casing walls due to centrifugal force, forming a rotating liquid ring.
As the impeller rotates, the space between the vanes and the liquid ring changes, creating alternating suction and compression chambers.
Gases are drawn into the pump through the suction port, trapped within the changing chamber volumes, and then compressed as the impeller rotates further.
Finally, the compressed gases are expelled through the discharge port.
Key Features:
Liquid Seal: The liquid ring acts as a dynamic seal, preventing gas leakage and enabling the pump to handle wet or even slightly dirty gases.
Self-Priming: Water ring vacuum pumps are self-priming, meaning they can handle some liquid carryover without damaging the pump.
Versatile: They are used in various industries, including chemical, food and beverage, and wastewater treatment.