Conveyor Systems Flashcards

What is a screw conveyor and what materials is it typically used for?

Answer: A conveyor using a helical screw (auger) rotating inside a trough to move bulk materials such as grain, cement, and powders

A screw conveyor consists of a helical screw (flight) rotating inside a U-shaped trough or enclosed tube. It efficiently moves bulk granular, powdery, and semi-solid materials horizontally or at slight inclines. Common applications include grain, cement, chemicals, and sludge.

What is the purpose of a gravity take-up on a long belt conveyor?

Answer: To automatically maintain constant belt tension using a weighted carriage that moves to compensate for belt stretch and thermal changes

A gravity take-up uses a weighted pulley carriage that rides on tracks. The weight applies constant tension to the belt, automatically compensating for belt stretch, thermal expansion/contraction, and load variations without manual adjustment.

What is a bucket elevator and what is it used for?

Answer: A vertical conveyor using buckets attached to a belt or chain to lift bulk materials to a higher elevation

A bucket elevator uses a series of buckets attached to a belt or chain loop running vertically between a head (top) pulley and a boot (bottom) pulley. Buckets scoop material at the bottom and discharge it at the top, providing efficient vertical transport of bulk materials.

What causes belt slippage on the drive pulley of a conveyor?

Answer: Insufficient belt tension, wet or worn pulley surface, or insufficient contact arc (wrap angle) between belt and drive pulley

Belt slippage occurs when the friction force between the belt and drive pulley is insufficient to transmit the required driving force. Causes include low belt tension, wet/smooth pulley surface reducing friction coefficient, and insufficient wrap angle around the drive pulley.

What is the purpose of a belt conveyor training idler?

Answer: To automatically correct belt mistracking by pivoting in response to belt drift and steering the belt back to center

Training idlers (self-aligning idlers) have a pivot mechanism that allows them to swivel when contacted by a drifting belt edge. The swiveling action creates a corrective steering force that guides the belt back toward center.

What maintenance check is critical on a chain conveyor?

Answer: Measuring chain elongation (stretch) to determine wear and verifying proper tension and lubrication

Chain elongation due to wear on pins and bushings is the primary wear indicator for chain conveyors. Regular measurement of chain pitch against original specifications indicates when the chain should be replaced. Proper tension and lubrication are also critical to chain life.