The design of storage bins and hoppers

Abstract

The storage bin, silo or hopper is one of the most important items of equipment in any bulk solids handling installation, since a poorly flowing hopper can have repercussions extending throughout the plant. All too often hoppers are ‘squeezed in’ after the remainder of the system has been designed, and this can result in various flow problems, such as those described generally as ‘arching’ or ‘rat-holing’ (section 2.3.4). Obviously, if this occurs, even the most sophisticated and expensive equipment downstream of the hopper will be unlikely to perform effectively because of the erratic supply of material. Part of the problem is often a lack of appreciation by designers and operators that, for a system to operate satisfactorily, bulk solid must flow from the hopper when required and in a predictable manner. Thus, as with any other part of the handling system, gravity-flow storage hoppers should be designed or selected to handle the actual product under consideration.