Tennessee Wastewater Operator Practice Exam

Which term describes a blower condition where the discharge airflow rate is very high but the discharge pressure is very low?

1. Surge

2. Choke

3. Stall

4. Backflow

The correct answer is: Choke

The correct term for a blower condition characterized by a high discharge airflow rate and very low discharge pressure is "choke." Choking occurs when the flow of gas through the blower reaches a point where the flow cannot increase even though the speed of the blower is increasing or maintaining a high output. This situation typically leads to a decrease in pressure because the blower is unable to generate enough pressure to maintain a corresponding increase in airflow. In this state, the blower is essentially operating beyond its optimal capacity for that specific gas flow condition, resulting in a mismatch where the demand for airflow exceeds the discharge pressure capabilities of the system. Understanding this principle is crucial for wastewater operators as it helps to identify performance limitations of blowers and optimize operation to maintain efficiency and system integrity. Other terms like surge, stall, and backflow involve different phenomena. Surge refers to oscillations in flow and pressure, stall typically involves a drop in airflow and pressure due to operational instability, and backflow indicates the reverse flow of air, none of which accurately describe the condition of having high airflow and low pressure.