Coarse Screen for Stp

stp plant

GENERAL

PRELIMINARY TREATMENT UNIT

Coarse Screen Chamber

There shall be two coarse screen chambers of RCC, one for installation of mechanical screen and one for installation of manual screen. The manual screen shall be ahead in the flow direction and the screen will be elevated above the side wall levels such that the RCC platform level matches the belt conveyor level to facilitate the least manual transfer of screenings on to the moving conveyor.

Necessary hand operated sluice gates shall be provided both in the upstream and down stream of the chamber to sluice either of the screens when it is taken out of service. A straight section, minimum of 3 times the width of the chamber, shall be ensured in the straight section upstream of the manual and mechanical screens. A belt conveyor system of suitable width shall be provided which shall be common to both mechanical screen and manual screen. This conveyor shall collect, transport and deliver the screenings through a FRP/SS chute at an elevation of 1.75 m above the level of adjacent service road such that the screenings drop automatically into a parked trailer / wheel barrow and hauled away for disposal without requiring manual handling. For inspection and maintenance of the screens & conveyor a RCC platform with handrails of 0.9 m height on both sides shall be constructed along the screen chamber with perpendicularly aligned access platforms to reach to screens for closer inspection of both screens and conveyor system. For off-situ repairs to be carried out to the screen, lifting of the screen assembly by mobile crane is contemplated. Isolation of the screens from the flow during either repairs or due to low flow conditions or due to rotational duty shall be through manually operated sluice gates as described earlier. The sluice gates shall conform to IS: 13349. The raw sewage shall enter the Inlet chamber by gravity through open channel. The operation of Screen & Belt Conveyer shall be...