Sewage Treatment Plant - Pre Screening (Bar Screen Chamber and Oil & Grease/Grit Trap: Functions, Operation, and Maintenance)
BAR SCREEN CHAMBER The function of the bar screen is to prevent entry of solid particles above a certain size; such as plastic cups, paper dishes, polythene bags into the STP. The screening is achieved by placing a screen made out of vertical bars, placed across the sewage flow. The gaps between the bars may vary between 10 and 25 mm. Larger STPs may have two screens: A coarse bar screen with larger gaps between bars, followed by a fine bar screen with smaller gaps between bars. In smaller STPs, a single fine bar screen may be adequate. 1 Inlet pipe for the STP. 2 Debris 3 Muck accumulates 4 Grill. Must be cleaned regularly to avoid a build-up of debris (2) and muck (3). 5 Screened sewage. 6 Outlet pipe (goes to the Equalization Tank) 7 Platform with weep holes. The STP operator stands here to rake the debris (2). Operation And Maintenance Considerations Check and clean the bar screen at frequent intervals Do not allow solids to overflow/ escape from ...