Book Description

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1919 edition. Excerpt: ...conditions for long life and high efliciency. The conveyor used in transporting clay from the pit, storage bins or cars to the crusher has severe abrasion to contend with. This abrasion is brought about by the varying sizes of the clay and the often incorrect method of delivering it to the belt with the resultant shifting of the load as it is conveyed along on its course. Clay is often damp, or even wet, especially in the winter months and the conveyor to the crusher should be belting capable of withstanding these adverse conditions. No cheap belting can do this and a low initial first cost is only false economy. Many conveyors distributing clay to various bins do so by means of mechanical trippers subjecting the belt to a reverse flexing strain. The installation of these conveyors is often made without proper regard to the fundamentals of good practice. The material carried should be fed in such a way_that when it strikes the belt, it is traveling in the same direction and at the same velocity as the belt. When the material handled is both coarse and fine, it should be fed over a grating for a short distance before striking the belt. This will let the fine material through to form a bed and protect the belt from the impact of the larger lumps. A carrying roller should be. placed a few inches back of the point where the material strikes the belt, and another about 2 ft. ahead. This provides the necessary support at the point of greatest impact, and at the same time takes advantage of the elasticity of the belt. The material should never be fed to the belt directly over a roller, as the impact of the material is apt to break the roller and is sure to wear the belt excessively. Imperfect alinement, particularly of the return rollers...