A Review of Models for the Prediction of Air Velocities in the Vicinity of Local Exhaust Ventilation Hoods in Bulk Solids Handling Systems

Due to continuing increases in the stringency of environmental legislation, both in respect of the workplace and the external environment, the control of dust generated during bulk handling operations by the use of local exhaust ventilation (LEV) systems continues to grow in importance. This combines with the increasing awareness of energy conservation in industry to require the design of ever more efficient LEV systems. In many cases, the most critical part of any LEV system is the interface between the dust generating operation and the LEV system i.e. the hood. With this in mind, this paper reviews the work of the major workers of the last 40-50 years in this area. The paper presents a qualitative and quantitative analysis of the works of the various authors. It also details possible routes forward in improving such models, including the application of finite element computational fluid dynamics (CFD) techniques, the use of which are currently under investigation at The Wolfson Centre.