-
Uninterrupted flow of filtrate
-
Outstanding particulate removal
-
Prevention of solids breakthrough
-
A reject rate as low as 3 to 5 percent
-
No moving parts
-
No costly pumps (backwash, sediment, high-pressure, drain)
-
No electrically operated valves (influent, spray systems, drain)
-
No high pressure spray wash (unit taken off-line)
Sand filter technology has long offered great promise, but problems such as interrupted flow of filtrate, frequent solids breakthrough, high rejects rate, and high capital and media costs have traditionally proved a drawback. Today, however, water treatment experts nationwide are recognizing the proven advantages provided by Ashbrook’s Strata-Sand™ Continuous Operation Downflow Sandfilters, the first sand filter technology to offer continuous, steady-state operation in a multigrade, deep bed, downflow design. Strata-Sand Sand filters eliminate the problems associated with sand filter technology typically used in the past. The benefits of the Strata-Sand are proven and far-reaching.
HOW IT WORKS
Strata-Sand™ operation is straightforward and efficient. Strata-Sand™ includes no moving parts, so once operational levels are established with the effluent weir, only simple periodic maintenance is required. Influent is introduced to the top of the filter bed. It enters the filtrate screens, moving first through the outer coarse sand and progressing inwardly through increasingly finer and denser sand to achieve maximum filtration. Captured solids are drawn downward with the sand to the bottom of the cone through suction of an air lift. Both solids and sand then are transported upward and are separated in a washbox. The cleaned sand falls back to the filter bed to begin the process anew, with coarse-to-fine sand gradation naturally occurring. Throughout this ongoing process, the water level in the filter is maintained constant by the effluent weir. The entire process of filtration and sand cleaning is thus automatic and without interruption.
STRATA-SAND™ FILTER IN STAINLESS STEEL
STRATA-SAND™ FILTER IN CONCRETE BASIN