Mechanical conveyors that push material along a trough or through a tube are often called “scrapers.” Which of the following equipment types fall under this pushing/scraper category?

Introduction / Context:Conveyors may carry material on belts/buckets or push it along using blades/flights or a rotating screw. The latter operate by displacement within a trough or tube and are grouped as “scraper” types in many texts.

Given Data / Assumptions:

• Focus on push/drag action rather than carrying on a surface.
• Common industrial conveyor types listed.

Concept / Approach:Flight conveyors use moving flights to drag material along a trough. Screw conveyors use a rotating helical flight to push bulk solids through a U-trough or pipe. Both displace/push material rather than carry it externally like belts or buckets.

Step-by-Step Solution:Identify push-type conveyors among options.Exclude carry-type conveyors (belt/bucket).Select flight and screw conveyors together.

Verification / Alternative check:Plant handling references classify flight/drag and screw conveyors as displacement/pusher types.

Why Other Options Are Wrong:Bucket/Belt: carry material on containers/surfaces; not “scrapers.”

Common Pitfalls:Using “scraper” only for chain-drag flights and overlooking screws, which also push.

Final Answer:Both (b) and (c)