Short-distance conveying of loose, non-abrasive materials (e.g., garbage, grain, food waste): which conveyor is most suitable?
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AFlight conveyor
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BScrew conveyor
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CDrag conveyor
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DBelt conveyor
Answer
Correct Answer: Screw conveyor
Explanation
Introduction / Context:For localized transfers inside plants—like under-hopper discharge, short horizontal lifts, or inclined feeds—compact conveyors with simple containment are preferred for loose, non-abrasive materials.
Given Data / Assumptions:
- Materials: garbage, grain, food wastes (non-abrasive, moderate moisture).
- Distance: short (typically < 30 m per flight).
Concept / Approach:Screw conveyors are enclosed, compact, and cost-effective for short runs. They meter and convey simultaneously, tolerate variable feed, and prevent spillage and dusting. Belts excel at long distances; flights/drag conveyors are for heavier, abrasive, or sticky service.
Step-by-Step Solution:Match application (short, enclosed, metered) → screw conveyor.Eliminate alternatives based on distance and material abrasiveness.Select “Screw conveyor.”
Verification / Alternative check:Facility layouts in grain and food plants commonly use screws under bins, mixers, and for short transfers.
Why Other Options Are Wrong:Belt: better for long runs.Flight/drag: robust but higher wear and power for this gentle service.
Common Pitfalls:Using screws for very long distances (inefficient) or very abrasive solids (rapid wear).
Final Answer:Screw conveyor