A large carrot processor near Bakersfield, California was unsatisfied with the performance of their existing disc filter system.
The effluent from the disc filters was fed to a spray system to be reused to irrigate crops used for animal feed. The solids concentration in the recycled water that entered their irrigation system determined how large an area the spray could cover; the higher the solids content, the lower the area - and the lower the efficiency.
Despite having 75-micron screens, the existing disc filters were allowing too many solids through, reducing the amount of water recycling that the plant could achieve.
In addition, the captured solids coming from the disc filters also had to go to a separate dewatering system. This dewatering system was nearing the end of its usable life and produced a very wet product that was difficult to handle and expensive to haul.
The plant selected a Hydro MicroScreen™ ultrafine rotating belt screening system, and tested it on the same flows that the disc filter system treated.
Output from both systems was sent to a laboratory for independent analysis of solids removal performance.
Under representative operating conditions the Hydro MicroScreen™ system removed 100% more solids than the disc filter for a given volume of flows - this meant that the plant could double the area reached by the recycled water irrigation sprays and drastically increase efficiency.
Additionally, output from the Hydro MicroScreen™ with integral dewatering was 30% lighter by volumetric weight.
As a result of the side-by-side trial the plant discovered that the disc filter system was missing 240 cubic feet (6.7 m3) of solids during every 8-hour shift of operation.