FM Techie

FILTER FEED PUMPS Filter Feed Pumps are used to draw water from the clarified water sump and pass it through the Pressure Sand Filter (PSF) and Activated Carbon Filter (ACF), which are installed in series to improve water quality. PRESSURE SAND FILTER (PSF) Working Principle: The upper layers of sand perform the actual filtration function, while gravel layers provide physical support. Specialized sand with a specific particle size is used to trap solid impurities present in water. The particles get entrapped in the spaces between sand grains, eventually blocking water flow. When the pressure drops beyond a set limit, the sand is cleaned by backwashing with water. Backwashing reverses the flow, fluidizing the sand bed and removing lighter solid particles as waste. Operation And Maintenance Considerations Filtration is followed by a short backwash sequence. The filter requires backwashing when the pressure drop across the filter reaches 0.5 kg/cm². Best practice: Backwash once per shift,...

CLARIFIER/ SETTLING TANK 1 The sewage inlet pipe brings sewage from the aeration tank. 2 The center-feed well takes this incoming sewage and gently releases it in the settling tank, without causing any disturbance or turbulence. 3 The sludge is only slightly heavier than water; so it takes time to sink. It slides down the steeply sloped walls of the tank toward the center of the bottom. 4 The bacterial flocs7 collect here in high concentration. 5 The sludge delivery pipe delivers the slurry to the pumps (6). 6 There are two identical pumps. Since the flow rate of these pumps is fixed, they need to be turned off periodically to bring down the net flow rate to achieve the desired MLSS ratio. This is a critical operation, because if flocs remain in the settling tank for more than 30 minutes, the microorganisms die due to lack of oxygen. 7 The T-shaped header assemble joins the outlet pipes of both pumps, and delivers the sludge to the aeration tank. 8 The clear water rises to the top of t...