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Making matters worse for Graterford Prison, the trash and debris often included full sheets, blankets, clothing, shoes, and plastics, which the prisoners stuffed into the toilets in their cells and flushed. The ensuing sewage clogs, backups and flooding created headaches for the maintenance staff and interfered with the institution's functioning.
The crushing load of debris adversely affected downstream equipment. Pumps would often clog and jam, requiring endless maintenance and emergency repairs. Pump bearings and seals would be damaged and need to be replaced, causing frequent system downtime.
According to Stan Pace, utility supervisor, the main problem was the equipment. "The equipment worked too slowly," said Pace. "We were running 650,000 gallons per day. Our obsolete units could not handle the flow."
A solution was urgently needed and that's when the prison called on Franklin Miller for help.
"Franklin Miller engineers evaluated the problems associated with the plant's wastewater discharge and equipment problems. They suggested one of their Spiralift auger screening and grinding systems," said Pace.
The Spiralift SLX system, specifically designed for screening of heavy prison and institutional effluent, was selected and installed for each channel, which was design to process a maximum flow of 1.5 mgd each.
The screening systems provide screening, washing, conveying, and compacting of wastewater solids in one integrated, easy to install system. The SLX features a heavy Taskmaster TM1630 shredder with a 10 HP motor and drive coupled with an oversized auger style channel screen, which removes the solids.
Once installed, the Taskmaster TM1600 shredder quickly went to work finely shredding all the heavy solids in the flow. The "confetti sized" particles were captured on the screen and intensively washed.
As the solids were conveyed up the transport, free water drained back into the channel and the solids were discharged into a bin with moisture reduced by over 50%.
"The Spiralift worked," commented Rusty Brown, maintenance operator. "None of us wanted to believe it until we saw it in action."
After only a few weeks in operation, the results were dramatic. Problems with the pumps were eliminated, as were maintenance calls in the middle of the night.
"Spiralift technology has made our plant run 98% more efficient," said Pace. "It's our first line of defense."