MHP preference is always for an underbelt scraper where possible, as, by definition, this is fail safe in the event of unforeseen impact. The disposal of tailings is also important and provision must be made for their collection or, ideally, return to the material stream.
The difficulty with belt scrapers is in maintaining performance with minimal maintenance over and extended period, both in accommodating wear and material build-up.
To work effectively blades must exert pressure on the belt. To do this they must be thin and therefore made from highly wear resistant material such as tungsten carbide. Softer materials may appear to offer safety however will not maintain performance owing to wear. Also, with modern designs, the blade support can deal with the likely conditions so tungsten carbide is the preferred material.
All blades will wear and this can be accommodated in one of two ways, a segmental blade, or a flexible blade which is controlled to move in such a way as to maintain scraping pressure. MHP offer both alternatives, in a range of designs to suit every application and budget.
Sometimes, despite extremely compact designs, there is insufficient space to install an underbelt scraper, or deal with the tailings, in which case a drum scraper is the best option. Modern designs have developed a long way in recent years and equipment for effective, long term scraping of abrasive materials is now readily available.
Vee or diagonal plough scrapers are used on the inside surface of the return strand of the belt to ensure that tramp material is removed before becoming trapped between tail drum and belt causing puncture damage.
MHP can supply spare blades and components for many popular scrapers.