Tennessee Wastewater Operator Practice Exam

Which type of blower produces a fairly wide range of airflow rates over varying pressure conditions?

1. Positive displacement

2. Centrifugal

3. Roots

4. Diaphragm

The correct answer is: Centrifugal

The centrifugal blower is recognized for its ability to produce a wide range of airflow rates while adapting to varying pressure conditions. This is due to its design, which utilizes the principles of centrifugal force. As air is drawn into the blower, it is accelerated outward by rotating blades or impellers, converting rotational energy into fluid kinetic energy. This process allows centrifugal blowers to maintain a high volume of airflow even when system pressures fluctuate. Their performance curve is characterized by a relatively stable flow rate across different pressure levels, making them particularly effective in applications where airflow needs to be consistent despite changes in system resistance. In contrast, positive displacement, Roots, and diaphragm blowers generally deliver a more fixed volume based on their design and may not adjust as efficiently to significant variations in pressure, thus making them less versatile in applications requiring a wide range of airflow.