Design of Grit Chamber
Design a grit chamber of rectangular cross-section. Following information is provided: Design Flow (Q): 50 MLD; Settling velocity of the smallest particle to be removed completely is 0.0236 m/s; Specific Gravity of particles (Ss): 2.65; Horizontal mean flow velocity (V): 0.30 m/s; Theoretical depth (D): 1.4 m; Calculate the dimensions and slope (mm/m) of the grit chamber. While designing the actual grit chamber, add 25 percent to the depth for grit collection, and 0.25m freeboard. Also add 50 percent to the theoretically calculated length. Value of Manning’s ‘n’ is 0.020. Assuming that the volume of grit in the wastewater is 0.15 m3/ML, and 100 percent grit removal in the grit chamber, calculate the total mass and mass of dry grit produced per day. The collected grit has a porosity of 0.5.
