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Finding the “Right” Screen for Your Application

The Bridge Street Pump Station in Omaha, NE was built in the 1940’s and never had a mechanical bar screen.  Manual bar racks for the subdivision pump station have to be cleaned a couple times a week during normal dry weather flows and every day when a storm occurs.  Occasional pump plugging and channel overflow occur if the cleaning schedules are interrupted.   Additionally, the pump station is expected to be removed from the collection system in the next 10 years as part of the City’s CSO program.  So when you don’t want to spend a lot of money but still want a rugged low flow screen that can operate 24/7 flawlessly, who do you go to?  Vulcan Industries, Inc. of course!  Vulcan installed its newest low flow screen offering – the Vulcan Knuckle Rake (VKR) multiple rake bar screen – in one of two existing channels within the pump station.  Immediately, it was noticed that the amount of screenings removed was significantly higher than that of the manual bar rack, but more importantly, pump cycles were improved with the consistent flow entering the wet well and pump plugging / channel overflows have been eliminated.   All without worrying if manpower is available to clean the manual bar racks.

So what’s different about the VKR design?  First, the VKR is a multiple rake bar screen, but does not use conventional roller chains for driving the rakes.  The VKR is fitted with a unique knuckle chain link that only bends in one direction.  This allows the engagement of the rake teeth into the bar rack by forming its own lower turn-around without a sprocket or guide rail system.  Additionally, the formed return feature at the drive end provides for engagement of the “quad-pin” drive sprocket that is keyed to the drive shaft.  Another difference is the rake shape.  Competitor’s designs use a stiffening angle pointing towards the channel invert on the upward travel of the rake.  Vulcan reversed this stiffening angle and points toward the drive end on the upward travel of the rake.  The stiffening angle also acts as a “scoop shovel” to contain screenings collected from the bar rack and significantly reduce the amount of screenings falling off the rake.

Vulcan screens are known for their robust durability without requiring overwhelming preventive maintenance to keep the equipment running.  The VKR Multiple Rake Screen takes that legendary experience to the low flow applications where options for good screening equipment have been limited.  Come see what might be the answer to your needs.