Why do dentists' drills commonly use pneumatic (air-driven) power rather than hydraulic or electric?
ACompressed air is stronger than hydraulics
BAir is clean, lightweight, and allows very high rotation speeds in a small tool
CPneumatic drills are quieter
DThere is no particular reason -- any power source would work equally well
Dental drills require very high speeds (up to 400,000 RPM) in a tiny, lightweight handpiece. Air turbines achieve this easily. Air is also clean -- a hydraulic leak in a patient's mouth would be disastrous. The air exhaust is harmless.
Question 2 True / False
A pneumatic cylinder can hold a heavy load in a fixed position as precisely as a hydraulic cylinder.
TTrue
FFalse
Answer: False
Air is compressible, so a pneumatic cylinder under load acts like a spring -- the piston can shift as the load changes. A hydraulic cylinder with incompressible oil locks the piston rigidly in place. This is why hydraulics are preferred for heavy lifting and precise positioning.
Question 3 Short Answer
What is the main advantage of pneumatic systems over hydraulic systems in food processing plants?
Think about your answer, then reveal below.
Model answer: Pneumatic systems use air, so leaks do not contaminate food products. A hydraulic leak would release oil onto food, creating contamination and safety hazards. Air leaks are harmless and do not require cleanup.
Cleanliness is critical in food processing. Pneumatic systems also avoid the need for hydraulic fluid reservoirs, filters, and return lines near food handling areas. The trade-off is lower force capability, which is acceptable for most food packaging and sorting tasks.