The scraper types adopted in universal design are shown in the figure. T-shaped and U-shaped scrapers are used in MS buried scraper conveyors; V-shaped and O-shaped scrapers are used in MC buried scraper conveyors; MZ buried scraper conveyors only use V-shaped scrapers. U-shaped and O-shaped scrapers are often used with double-row chains.
The selection of scraper types is mainly based on the properties of the conveyed materials and is also limited by the structure of the conveyor itself. The general methods for selection are as follows:
(1) For materials with good conveying performance or not too large particle size, simple scraper types such as T-shaped, V-shaped, and O-shaped can be selected;
(2) For materials with high suspensibility and fluidity, to ensure that sufficient internal friction can be generated between materials to overcome external resistance and self-weight, more complex scraper types such as U-shaped or O-shaped should be selected;
(3) For materials with high adhesiveness, simple scraper types should be selected to reduce the difficulty of unloading and cleaning caused by adhesion on the scraper surface;
(4) When conveying materials with high density and large trough width, to ensure the strength and rigidity of the scraper and prevent deformation or fracture, scraper types with diagonal braces, such as O-shaped, should be selected;
(5) When using MZ buried scraper conveyors or MC buried scraper conveyors with B-type heads with idlers, due to specific structural requirements, only V-shaped open scrapers can be used;
(6) When conveying materials prone to floating chains, the scraper can be welded onto the chain at a 70° angle to generate a vertical downward force from the motion resistance. At this time, the normal meshing of the scraper chain with the head wheel should be verified for die-forged chains and double-row chains.
