The city of Plymouth processes 150,000 gal of raw sewage a day. Before 2009, the plant had no headworks installed at all. The raw sewage was being dumped into a pond. Because of this, the plant suffered major ongoing sludge and BOD problems. A city engineer recommended a new system be installed to combat these problems. After doing research, the engineer found a Franklin Miller system that proved to be a solution.
In 2009, the city installed a system consisting of a Spiralift S and Spiralift SC. The system screens the raw sewage, removes solids that do not break down, and washes and conditions them. Greg Wood, chief wastewater operator, reports the plant is very happy with the Spiralift System. “It works well and really does its job! It never goes down or offline,” said Wood.
The Spiralift screens both use augers to process the solids. The Spiralift S channel screen has a shaftless auger design. Solids captured on its semicircular screen are swept from the screen by brushes affixed to the perimeter of the auger, washed and transported up to a discharge. The screenings then fall into the SC Screenings Conditioner.
The Spiralift SC employs two technologies for optimal washing. First, a Taskmaster grinder reduces the solids to uniform particles exposing multiple surfaces to the washing action. Next, the Spiralift SC intensively washes organics and flushes them back into the system. The unit’s auger then conveys the solids into the unit’s press zone. The output is deposited into a bin, bag or conveyor — washed, grinded and reduced in weight. The grinder and press technology, along with highly rugged construction, makes the SC uniquely effective.
Wood performs very basic maintenance, oiling and cleaning the machines once a year. “In addition, the city has had to replace the brushes only once in all these years,” Wood said.
Before installing the Franklin Miller system, the sludge and BOD problems caused a lot of headaches at the plant on a regular basis. The Spiralift system has eliminated them all. “Now, we have no problems,” Wood said.