Design Issues With Materials Handling
Abstract
Traditional design techniques for bulk solids conveying equipment have been developed around large scale operations (rates of 1000 tonnes/hour upward).
This paper provides design practice notes for applications where transfer rates are much smaller (often 1 to 2 orders of magnitude less) using the fertiliser industry as an example. This large difference in capacity generally means the use of scale up/down techniques cannot be successfully applied.
For smaller industries where solids conveying is required, using traditional documented design approaches will often result in over designed and specified plant. Furthermore, it is typical for smaller industries to handle a wide variety of materials with different physical properties requiring additional considerations by the designer. The use of complex computer aided design programs will often provide an incorrect result and add costs to the equipment. As such there is a requirement for specialist inputs by the designer to ensure an appropriate solution for these applications.
This level of design input can result in the design cost increasing as a proportion of the capital cost, compared to typical (industrial) ratios, which is more a function of the lower capital cost of the plant rather than an increased design effort. Hence, there is a need to make use of specialist techniques, standardised designs, and uniform components (without unnecessarily oversizing and so defeating the purpose of application of appropriate design) for each installation.
This paper briefly summarises some techniques employed to minimise overall costs yet ensure the equipment is fit for purpose.
Authors
Richard Greenwood & John Wheadon
Sinclair Knight Merz