Automatic Systems: Getting Inside Water Reuse Filtration

What qualities should a filtration system possess? The three keys to success at one wastewater treatment plant are simplicity of design, cleaning efficiency, and reliability due to few moving parts

Filter products from Amiad Filtration Systems were selected and installed for the expanded 20.25 MGD water reuse system at the City of St. Cloud’s Michigan Avenue wastewater treatment plant in Florida. The self-cleaning automatic system uses six model EBS-10,000 units with a filtration degree of 200 microns. The cleaning mechanism relies on a suction scanner “focus back-flush” technology, which takes advantage of simple physics for cleaning. In fact, this “focus back-flush” concept exhibits 100 percent cleaning.

The cleaning nozzle is designed within close tolerances to cylindrical screen for high efficiency of back-flushing. During a back-flush cycle, water moves both tangentially and directly into the orifice of the nozzle due to the large difference between operating and atmospheric pressures. The high velocity (50 ft/sec²) and spiral movement of the nozzle across every square inch of screen area combine to remove the entire filter cake effectively without any interruption of flow through the filter units. Typically, back-flushing wastewater is less than 1 percent of total flow.

Installation of the filter products at the plant was commissioned last September. The decision to use these products was based on the experience of a smaller and successfully operating system installed in 2003.

Amiad Filtration Systems, Oxnard, CA; 800-969-4055; www.amaidusa.com