Numerical investigation of stress–strain and deformation characteristics imposed upon automatic screener rakes

Automatic bar type screeners are used as a primary filtration device in water flowing channels to remove unwanted solid materials from the influent. To reduce manpower, automatic mechanisms are used to clean screeners that are clogged with debris of various sizes. The rake experiences fatigue loading when water passes through the gate during the cleaning process. Therefore, the components must be designed to withstand the induced stresses. The teeth or pin is the crucial component in completing the function of the rake. However, it may rupture under periodic loadings. Replacing the pin requires a considerable amount of time and immense manpower. To solve this problem, this study first performs a structural analysis to predict stress distribution and total deformation on the individual pins under various types of loadings. A rake pin design with a rib is analyzed for the same loadings; the design demonstrated improved stress distribution with significantly small deformation. The results show that the mid-section of the rake, which is the most stress intensive region, must be carefully loaded to avoid fracture.