How automatic self cleaning screen filters work.


VAF's flagship product is their line of automatic self cleaning filters, the V-Series. 

The V-Series design is the most recent, state-of-the-art self-cleaning screen filtration technology available today. The complexity and cleaning efficiency of any self-cleaning screen filter is in the mechanical system that drives the cleaning process.

The V-Series patented Bi-directional Hydrodynamic Drive (BHD) mechanism is the simplest and most efficient in design resulting in the following:


The V-series self cleaning filter has fewer moving parts and up to 70% less parts than competitive designs. The state-of-the-art BHD mechanism also removes troublesome vessel penetrations that are typically handled with shaft seals. This simplistic design results in lower maintenance costs and less requirements for proper training. 


The V-series cleaning cycle is bi-directional and therefore cleans in two directions (forward and backward). Competitive products only clean in one direction. Because of this the V-Series' flush cycle is only 12 to 15 seconds resulting in approximately half of the water usage of competitive designs. This cycle is automatically initiated when the pressure differential across the screen increases to 0.5 bar (7 psi) so that the filter only flushes when it's required. The filter remains on line and the filtration process remains uninterrupted during the cleaning process. 


The V-Series filters can be designed to ASME code and are manufactured in an ASME facility. Standard construction materials are reinforced nylon (for smaller applications) and 316L stainless steel (for larger, more robust applications). Due to rust susceptibility, VAF does not provide coated carbon steel body construction. The filters are available in a broad range of pressure, and temperature ratings to suit any need. 


Self cleaning filters appeal to many applications from domestic water to condenser water filtration. With an available micron range of 10-1500 micron, VAF self cleaning filters can be custom suited to almost any application.  Additionally, these filters carry NSF 61 certification, so engineers and owners can rest assured that they are safe for use in domestic water systems. VAF custom manufactures filters and skids that simplify installation and meet specific requirements.

Submicron sand Filtration

The Vortisand technology uses a tangential inlet to introduce water in the filter vessel with a kinetic energy that creates a unique swirling action. Using this vortex effect to provide a crossflow filtration condition, the Vortisand allows the water to flow parallel to the top layer, producing a sustained cleaning action that forces the suspended solids to accumulate on the inside wall of the vessel and in the water above the media.


Thanks to the vortex effect, microsand can be used to filter out the fine particles without clogging rapidly. Thus, contaminants are trapped above the sand and are easily removed using an automatic backwash cycle, which requires less water and a shorter backwash sequence than traditional sand or multi-media filters, especially since most of the solids are not captured in the media. The end result is a technology that can remove down to submicron levels at 4 to 5 times the flow rate of other media filters, while requiring 50% less water for backwash.


The Vortisand sand filter combines centrifugal separation and sand filtration into a single vessel. This reduces footprint while maintaining industry leading performance.


Typically ~85% of suspended solids in water systems are smaller than 5 microns. While filtering out larger particles is important to maintaining equipment life, these microscopic particles are primarly responsible for equipment fouling and efficiency degradation. Vortisand's sand filter ensures that the other equipment on the system is capable of operating at peak efficiency by providing submicron filtration that is 10 to 20 times finer than other media filters.