The Filtrex System  Depending on the application, the Filtrex candles are grouped into vessels, varying in number from a single candle to as many as several hundred. Each Filtrex candle is held in suspension from a support plate, referred to as a tube sheet. The candle assemblies are lowered and secured in place into the filter vessels, usually consisting of an upper and lower chamber. The dirty fluid enters the filter vessel from the lower chamber flowing radially across the filter elements where filtration will occur. The fluid will then be transported, via the element integral conduits, to the upper chamber, now as clean filtrate. The upper chamber also functions as the self-contained reservoir where a residual volume of the clean fluid is used to backwash and clean the filter elements.

Service Cycle - No Precoat  Dirty fluid will enter the lower filter vessel chamber flowing radially across the filter elements. It enters the Micro-Grooves at the outer diameter of the element arcs and exits through cavities which are integrally formed into the filter elements. Contaminants are intercepted either directly or through bridging across the filter pores. The clean fluid is transported through the cavities into the upper chamber and out to the service connections. The service cycle will continue until a predetermined differential pressure across the filter is reached. At this point the Backwash Cycle will be initiated. Please download the interactive disc for an animated description of this cycle.

Service Cycle With Precoat Precoating is accomplished by circulating a slurry of filter aid, [such as diatomite, cellulose fibres, pearlites, carbon powder, deionizer chemicals, filtered or clean liquid] between the filter and a precoat tank. The filter aid particles create a coat over the filter candle. This coat now virtually becomes the filtering media, supported by the filter elements. This action is greatly enhanced in the Filtrex units due to the unique support feature offered by ledges created as a result of stacking the Filtrex wafers. The precoat cycle time takes 3 to 4 minutes to complete and forms an evenly distributed cake along the length of the filter candle. Various grades of precoat material are used to achieve the desired clarity and flow characteristics. Precoat body feeds are normally injected during services in order to enhance the service cycle time.

Backwash Cycle When backwashing is initiated, the self-contained reservoir is pressurized, (usually by air or any other pressurized media) to pressure ranges between 80-120 p.s.i. The drain valve is quickly opened, causing the fluid in the filter vessel to flow in a reverse direction at extremely high velocities. The produced kinetic energy force acts to impact the compression plate, which further compresses the spring causing the filter wafers to loosen and momentarily separate. This action coupled with the vaccuming effect produced from the vessel emptying out in only a fraction of a second, cleans the candle elements and the vessel with extreme efficiency. The Backwash cycle takes less than 15 seconds to complete. If a rinse cycle is deemed necessary, an additional 15 seconds will be needed.