Abstract
M.Tech. (Mechanical Engineering)
Material wear formation on centrifugal fan impeller has been a major problem to many process plants in the whole world and this has been regarded as a grey area to many of OEM of extraction fans. TLT ACTOM has designed and manufactured an ID centrifugal fan for Sugar plant situated in Swaziland. The ID fan after a few months of operation the impeller was found to be subjected to wear. Wear initially took place such that the impeller could not last a season which is made of 9 months. The research was conducted to study the behaviour of wear taking place on the impeller material used in sugar mill plant. Establish the uncertainty of what type of wear is taking place and what cause this wear. The study focused on the formation particle flow pattern and minimization of wear to give a solution to fan manufacturers and end-user of the extraction fans. A visit to the plant in Swaziland was organized and during that site visit, bagasse and coal ash samples together with water samples were collected from inside of the venturi wet scrubber after the scrubber has been switched off for over a month for maintenance purposes. These samples were sent to a laboratory to analyse chemical compositions. The test aimed to determine particles sizes, a composition of mass in percentage, elements and mass of a chemical or contaminate per unit volume of water. A physical inspection has been performed on the wet scrubber to inspect if there were any trace that can lead to wear resulting from wet scrubber failing to perform what is expected from it. A correlation on how wear might have taken place on the impeller was conducted by using a CFD simulation. CFD simulation was conducted by using SolidWorks CAD software. Before conducting the simulation, calculations were made to determine parameters to be used as boundary conditions in the simulation software. Calculations were based on the actual centrifugal fan duties provided by the consultant company that was responsible for designing the entire plant system...