Why is a belt scraper important?
A belt scraper is a vitally important component of a conveyor belt system that is often overlooked and neglected.
The primary purpose of a belt scraper is to prevent material carry-back on the conveyor belt. By reducing material carry-back, conveyors can run more efficiently, with fewer breakdowns and lower running costs. Efficient and correctly adjusted belt scrapers save the plant operator money.
Missing or inefficient belt scrapers can cause safety hazards on site
Material carry-back results in spillage beneath conveyors and material build-up along structures and moving parts. These conditions can lead to more serious operational and safety issues.
Problems associated with poorly maintained belt scrapers include:
- Excessive build-up on rollers and pulleys
- Excessive wear on rollers and pulleys
- Misalignment of the conveyor belt due to artificial crowning on rollers
- Mis-tracking of the conveyor belt
- Damage to the conveyor belt top cover
Above image indicates excessive build-up.
There are several safety hazards associated with material spillage and build-up on conveyors. These include material falling onto people or vehicles, the inherent dangers involved in cleaning excessive build-up on conveyor structures, and the risk of fire caused by belt mis-tracking and misalignment.
A well-designed belt scraper will clean effectively, have a long wear life, and require minimal maintenance.
The efficiency of a belt scraper is affected by several factors:
- The condition of the belt scraper blade
- The condition of the conveyor belt surface
- The belt scraper tension and adjustment
- The belt scraper material
- The type and condition of the belt splice
- The speed of the conveyor belt
This image shows an efficient belt scraper.
The above image shows an excessively worn scraper blade.
The efficiency of belt scrapers should be monitored daily by the machine operator. Signs of excessive build-up, spillage, or material carry-back on the conveyor belt should be investigated and corrected. Typically, the operator will check wear on the scraper blade as well as scraper tension.
Belt scrapers with insufficient tension allow fine material to carry back and increase scraper wear. Excessive scraper tension can damage the conveyor belt cover, rapidly wear the scraper blade, and in some cases cause heat build-up.
Not every belt scraper design works with all materials. In particular, very wet or sticky materials may require specialised belt scrapers. In extreme cases, it may be necessary to install a primary belt scraper followed by a secondary belt scraper. Most belt scrapers feature adjustable mounting mechanisms that provide constant pressure on the belt and automatic compensation for wear and variations in belt thickness.
