OHST Practice Exam

In the design of a ventilation system, which of the following operations would require the greatest capture velocity?

1. Evaporation from open surface tanks

2. Spray booths

3. Welding

4. Grinding

The correct answer is: Grinding

The correct answer is that grinding would require the greatest capture velocity in the design of a ventilation system. This is primarily due to the nature of the dust and particulates generated during grinding processes. Grinding operations often produce fine particles that can become airborne quickly and disperse over a wide area. To ensure the effective capture of these particles before they can settle or be inhaled, a higher velocity is needed to draw them into the ventilation system. When designing the ventilation system, it is crucial to account for the particle size, weight, and the rate at which they can become suspended in the air. The higher the particle velocity required, the more powerful the ventilation system must be to maintain adequate air flow and ensure worker safety. In contrast, while evaporation from open surface tanks, spray booths, and welding also require appropriate capture velocities, the particulate generation in these operations is typically less severe compared to grinding. For example, welding generates fumes and gases which may require efficient ventilation but do not produce the same volume of fine particulates as grinding. Similarly, spray booths produce mists that can be captured with lower velocities than required to manage the dust from grinding activities. Therefore, the requirement for the greatest capture velocity is associated with the efficient removal of airborne particulates generated