In semiconductor fabrication facilities, laminar flow hoods maintain contamination-free work zones by forcing filtered air downward across benches at a calibrated velocity. If the airflow velocity drops below the required minimum, ambient room drafts overcome the stream and introduce airborne particles into the critical area. Conversely, if the velocity exceeds the specified maximum, the high-speed air generates turbulent eddies at the perimeter of the bench that draw surrounding unfiltered air back onto the work surface.
Based on this passage, which of the following is a logical conclusion regarding laminar airflow management?
- AHigher airflow velocities are always preferable because stronger downward air currents prevent drafts from entering the clean zone.
- Maintaining a contamination-free workspace requires operating airflow within a defined speed range because both insufficient and excessive velocities introduce impurities.Answer
- CHEPA filtration systems must be supplemented with chemical scrubbers whenever ambient cleanroom temperatures fluctuate.
- DExcessive fan speeds cause turbulent eddies that push contaminated air entirely out of the surrounding facility.
Answer
Maintaining a contamination-free workspace requires operating airflow within a defined speed range because both insufficient and excessive velocities introduce impurities.
The passage outlines two distinct failure modes: velocities below the minimum permit ambient drafts to carry in particles, while velocities above the maximum generate turbulent eddies that draw unfiltered air inward. Combining these two facts leads to the direct logical conclusion that airflow must remain strictly within a calibrated window to preserve contamination-free conditions.
Step-by-Step Solution
Key Concept
Synthesizing dual-boundary constraints to draw a logical deduction
Estimated Time:1m 5s