Contra-Shear Wastewater Screening Products.pdf - Johnson Screens

contra-shear ®InclinedRotary ScreenInclined rotary screen forcombined screening andcompactionThe Contra-Shear inclined rotary screen(IRS) is used for fine screening of sewageand industrial effluent where screeningand solid extraction capability is desiredwithin a single unit. Installed at an angleof 35 degrees, the screen drum isconstructed out of Vee-Wire ® screen,however perforated plate and meshdesigns are also offered.The influent enters into the feed end ofthe screen drum and exits through theVee-Wire slots or holes, as the case maybe. Solids larger than the slots or holesare retained and build up on the screensurface. This buildup increases the headloss across the screen, which initiatesthe rotation of the screen drum.The cycle and frequency of operationdepends on the application and theamount of solids captured. The solids aredropped into a central trough by a seriesof baffles welded inside the screen drum.A screw press, located inside the trough,transports and dewaters the solids as ittravels upwards towards the dischargeend.An automatic sparge system, comprisedof two sparge pipes with nozzles,operates when the screen drum rotatesand keeps the drum clean.The IRS is capable of handling flow ratesfrom 1,188 to 20,253 gpm (270 to 4,600m³/hr) through a single unit.Features and Benefits• Slot sizes from 0.02 to 0.24 in. (0.5 to 6.0 mm) with Vee-Wire models• Slot sizes from 0.08 in. (2 mm) and up with perforated plate and mesh models• 304SS or 316SS construction• Single motor drives the drum and the screw press• Compact, fully enclosed in-channel design• Low and consistent head loss• Self-cleaning operation• Low power consumption and operating costs• Heavy-duty construction• High solids capture