Tennessee Wastewater Operator Practice Exam

In a multistage centrifugal blower, what happens to the pressure as the air travels through each stage?

1. It decreases

2. It remains constant

3. It increases

4. It fluctuates

The correct answer is: It increases

In a multistage centrifugal blower, the pressure of the air increases as it travels through each stage. Each stage in the blower consists of an impeller and a diffuser. The impeller is responsible for adding energy to the air, converting kinetic energy into pressure energy. As the air moves through the impeller, it gains velocity and, as it exits the impeller into the diffuser, this velocity is converted into static pressure, resulting in an increase in pressure. As the air continues on to the next stage, it goes through another impeller and diffuser, further raising the pressure with each successive stage. This design allows multistage centrifugal blowers to efficiently handle higher pressure requirements by systematically increasing the pressure rather than relying on a single stage. Therefore, throughout the operation of a multistage centrifugal blower, the cumulative effect of multiple stages results in a continual increase in air pressure.