Design of ship loading chutes to reduce dust emissions



This article presents an industrial case study to reduce dust emissions from a grain handling ship loader. The primary objective of the study was to reduce dust emissions to within acceptable environmental levels during ship loading. Several constraints were imposed on the solution as the result of time and budgetary restrictions, and the inability to add a dust suppression agent to the grain for quality reasons. Although this article specifically deals with grain, application of this technology is also equally suitable for reducing dust emissions while handling other particulate commodities.

A number of alternative loading chute configurations and delivery spoon (a discharge device) profiles were examined in a pilot-scale test facility. This article discusses a number of alternative solutions that were investigated during the course of the study and the critical parameters of the final design. Tests showed that it was not beneficial to decelerate the product stream to keep the relative velocity of the air stream over the grain below the minimum pickup velocity. Instead, it was found that concentrating the product stream and keeping the product velocity high proved to be more beneficial in reducing dust emissions. A reduction of 50% in dust emission was achieved through the use of specifically designed constant-radius and parabolic-profile loading spoons. The product stream exiting the curved spoons was found to be concentrated and streamlined, resulting in the dust being contained within the product stream. © 2006 American Institute of Chemical Engineers Process Saf Prog 26: 229–234, 2007