roots rotary lobe blower

A Roots rotary lobe blower, also known as a Roots blower or a rotary lobe pump, is a type of positive displacement machine that moves a fixed volume of gas or fluid with each rotation of its impellers. It works by trapping a fixed amount of fluid between the impellers and the casing and then pushing it out the discharge port. These blowers are often used in applications requiring relatively constant flow rates at varying discharge pressures.

Here’s a more detailed explanation:

Positive Displacement:

Unlike centrifugal compressors, which rely on impeller speed to generate pressure, Roots blowers use a positive displacement principle. This means they trap a specific volume of gas or fluid and physically move it from the inlet to the outlet.
Lobe Design:

The key component is a pair of rotating lobes (or impellers) that are typically shaped like figure-8s or have a similar profile.
Operation:

As the lobes rotate, they trap pockets of gas or fluid between the lobes and the blower’s casing. Each rotation moves a fixed amount of the trapped material from the inlet to the outlet, regardless of the discharge pressure.
Applications:
Roots blowers are commonly used in various applications, including:

Industrial Processes: Providing air or gas for processes that require a relatively constant flow, like wastewater treatment or pneumatic conveying.

Superchargers: Found in some engines as a supercharger to boost engine performance by forcing more air into the cylinders.

Vacuum Systems: Can be used in vacuum systems to remove gases from a space.
Advantages:
Constant Flow: Delivers a relatively consistent flow rate, regardless of pressure changes.

Simplicity: Relatively simple design and construction.

Versatility: Can be used for both positive pressure and vacuum applications.