The Mechanical Handling and Storing of Material

ELEVATORS FOR MATERIAL IN BULK 21 small consequence when dealing with whole grain, but when elevating flour or finer light material this draught of air is most objectionable, as the dust blows out through all the crevices of the elevator casing, and if any door in the elevator is opened a blast of dust will issue from the opening. If, however, the discharge spout be placed about level with, or, better, a few inches below the under side of the pulley, the discharge will be a perfect one, provided the elevator is running at the correct speed, and the buckets of proper form. Usually these elevators are cased in a wooden box or pair of boxes or trunks which enclose the elevator legs. A space of to 2 in. should be allowed between the buckets and the trunk in order to obviate any possibility of the ouckets touching the trunk; and further, if the buckets are fitting too close, they are also apt to act as a fan and create a draught, which means dust. The elevator top which covers the pulley, and which also carries the bearings for the top spindle, may be made either of wood or iron. For ordinary use in flour mills and other factories dealing with light material wood is preferable, as it is easier to attach to the woodwork of the roof or the floor of the building. Iron elevator tops are used in cases where the trunking is also made of iron, in order that it may be fireproof. This particularly applies to the wheat-cleaning department of flour mills, to provender mills, or to fireproof factory buildings. It is advisable to vary the shape of the buckets for the different products they have to handle. A shallow bucket is best for soft and clinging material such as flour, cement, fine or moist sugar, etc., whilst for harder material, such as cereals, etc., a deeper bucket