Eriez says that it works continuously with minimal operator attention and provides consistent solids separation, maximum coolant life and increased productivity for the metalworking industry. The design provides positive filtration levels to 10 microns because of a method that seals the filter media to prevent solids bypass. The system also has the capacity to effectively handle flow rates up to 2,000 gallons per minute (7,570 litres per minute).According to Eriez, Hydroflow Vacuum Filters have a number of advantages over conventional flat bed pressure filters, cyclonic and pre-coat pressure filters. These include that the vacuum filtration design replaces costly and complex hydraulic or air closure systems that typically seal flat bed pressure filters. The vacuum pump handles clean coolant only, as it draws the dirty fluid through the media, eliminating the wear associated with pumping dirty coolant. In addition, the conveyorised dirty tank and filter section is in one assembly eliminating the settling, backflow and balance problems associated with pressure filters. The system provides for the complete removal of solids from the dirty tank and removes settled solids. Automatic regeneration uses a small clean tank to provide an uninterrupted flow of clean fluid to the point of use. By introducing only a small section of new media into the filter section, the Vacuum Filter eliminates the filtration spikes caused by pressure filters that index the entire filter bed. Finally, the Hydroflow Vacuum Systems do not use air for backwash or to dry the solids discharge, eliminating the need for additional air compressors, accumulators or mist collectors.Eriez also offers the Hydroflow CBN Series Vacuum Filters, specifically designed to handle heavy oils, aerated by very high pressure (up to 1,000 PSI) and the blinding and short cycling associated with CBN machining. The CBN Series features high flow rates (up to 100 gallons per minute or 378 litres per minute) at high pressures (up to 1,000 PSI). One advantage of this system is the positive displacement air-operated filter pumps, which are extremely effective on highly-aerated heavy oils. Special filters are available with refrigeration systems mounted on top of the filter.