433A Conveyor Systems 1 — Questions and Answers
Question 1: What is the function of a take-up system on a belt conveyor?
- To speed up the belt
- To maintain proper belt tension for adequate friction between the belt and drive pulley, and to remove belt slack (Correct answer)
- To guide material onto the belt
- To clean the belt surface
Correct answer: To maintain proper belt tension for adequate friction between the belt and drive pulley, and to remove belt slack
A take-up system maintains the correct belt tension required for the drive pulley to transmit force to the belt without slipping. It also removes slack that develops from belt stretch over time. Types include screw, gravity, and automatic hydraulic take-ups.
Question 2: What causes belt mistracking (belt running off to one side) on a conveyor?
- Belt moving too fast
- Misaligned idlers, uneven loading, damaged belt edge, misaligned structure, or material buildup on pulleys (Correct answer)
- Belt color fading
- Using the correct belt type
Correct answer: Misaligned idlers, uneven loading, damaged belt edge, misaligned structure, or material buildup on pulleys
Belt mistracking is caused by any force imbalance across the belt width: misaligned idlers or pulleys, off-center material loading, uneven belt tension, material buildup on one side of a pulley, damaged or uneven belt edges, or structural misalignment.
Question 3: What is the purpose of a belt scraper (cleaner) on a conveyor?
- To sharpen the belt edge
- To remove material adhering to the belt after discharge to prevent carryback, belt damage, and idler fouling (Correct answer)
- To slow the belt speed
- To straighten the belt
Correct answer: To remove material adhering to the belt after discharge to prevent carryback, belt damage, and idler fouling
Belt scrapers remove residual material (carryback) clinging to the belt after the discharge point. Carryback that falls off under the return strand fouls idlers, builds up on pulleys causing mistracking, and creates housekeeping problems.
Question 4: What is a troughing idler on a belt conveyor?
- An idler that creates problems
- A set of rollers arranged in a trough shape (typically three rollers at angles) to carry the loaded belt and contain the material (Correct answer)
- A single flat roller
- An idler used only on the return run
Correct answer: A set of rollers arranged in a trough shape (typically three rollers at angles) to carry the loaded belt and contain the material
A troughing idler consists of three (or five) rollers arranged in a trough configuration — the center roller is horizontal and the wing rollers are angled upward (typically 20, 35, or 45 degrees). This shape increases the belt's material carrying capacity and prevents spillage.
Question 5: What is the function of an impact idler at the loading zone of a conveyor?
- To increase belt speed at the loading point
- To absorb the impact energy of material falling onto the belt, protecting the belt from damage and reducing wear (Correct answer)
- To direct material flow off the belt
- To measure the weight of material being loaded
Correct answer: To absorb the impact energy of material falling onto the belt, protecting the belt from damage and reducing wear
Impact idlers have rubber disc or cushion rollers that absorb the impact energy when heavy or lumpy material falls onto the belt at the loading point. They protect the belt from impact damage, punctures, and premature wear.
Question 6: What is the purpose of a skirt board on a belt conveyor?
- To decorate the conveyor frame
- To contain material on the belt at the loading zone, preventing spillage as material settles onto the moving belt (Correct answer)
- To support the return belt run
- To clean the pulleys
Correct answer: To contain material on the belt at the loading zone, preventing spillage as material settles onto the moving belt
Skirt boards are plates mounted along both sides of the belt at the loading zone with rubber skirt seals that contact the belt edge. They contain material on the belt until it settles and centers, preventing spillage during the turbulent loading process.
433A Conveyor Systems 1
What is the function of a take-up system on a belt conveyor?