1 Hydroflow Filtration Systems F I L T R A T I O N S Y S T E M S HYDROFLOW SURFACE FILTRATION Versus DEPTH FILTRATION In Metalworking Fluids SURFACE FILTRATION, refers to a method which traps particulate on the surface of a disposable or permanent filter media. The solids in the fluid need to stack up on each other and build a filter cake to increase the effectiveness and efficiency of the system. In flat bed vacuum or pressure filters, the performance depends on the nature of the solids, the distribution of the particle sizes and the velocity thought the media. Generally, Micron is the best level of filtration on flat bed, surface filters – ROLL MEDIA OR PERMANENT MEDIA VACUUM AND PRESSURE FILTERS DEPTH FILTRATION, refers to a method which traps particles throughout the cross-section of the filter medium. These are also referred to as Pre-Coat Filters. In the case of the Star Filter, the medium is the cellulose “filter aid” which provides a wide distribution of particles, establishes an effective filter cake and provides great dirty holding capacity. Because of the many types and grades of available filter-aids, Pre-Coat Filters can provide filtration to 1 Micron. PRECOATED PRESSURE FILTERS, STAR FILTER
2 Hydroflow Filtration Systems F I L T R A T I O N S Y S T E M S HYDROFLOW A Wide Distribution Of Particle Size And Shape Creates The Best Filter Cake And Yields High Filter Efficiency Coarse Grinding, Aluminum Oxide Wheels Conventional and Creep Feed Grinding, Where A Mix Of Material And Wheel Brake Down Is Present BUILDING A FILTER CAKE Filter Cake Filter Media Or Septum
3 Hydroflow Filtration Systems F I L T R A T I O N S Y S T E M S HYDROFLOW A Narrow Distribution Of Particle Size And Shape Seals Off The Filter Media Which Results In Less Dirt Holding And Increase Operation Cost Fine Grinding, Honing Diamond & CBN Wheels Cast Iron, Carbide, Glass & Ceramics SURFACE BLINDING Surface Blinding Filter Media Or Septum
4 Hydroflow Filtration Systems F I L T R A T I O N S Y S T E M S HYDROFLOW A Filter Aid Can Be Used To “Precoat” The Filter Septum Creating A Filter Cake For Trapping The Fine Particulate FILTER AIDS - PRECOAT Precoat Filter Filter Media Or Septum
5 Hydroflow Filtration Systems F I L T R A T I O N S Y S T E M S HYDROFLOW THE KEY INGREDIENTS TO BUILDING A CAKE: Good Distribution Of Solids Large Amount Of Filter Area
6 Hydroflow Filtration Systems F I L T R A T I O N S Y S T E M S HYDROFLOW In Cake Building applications, The amount of dirt a given area can hold is based on the flow rate or velocity through the media FILTER AREA Low Flow Allows The Cake To Build, Keeping The Paths Open For Additional Flow To Pass and Dirt to be captured 10 Square Feet Of Filter Area. High Flow Causes The Cake To Compress, Restricting The Paths, Leading To Premature Loading 1 Square Foot Of Filter Area.
7 Hydroflow Filtration Systems F I L T R A T I O N S Y S T E M S HYDROFLOW Permanent Or Disposable Roll Media Reduces The Ability To Build A Cake And Leads To Surface Blinding And Reduced Efficiency Heavy Dirt Load And / Or A Poor Distribution Of Particle Shape & Size FLAT BED SURFACE FILTRATION
8 Hydroflow Filtration Systems F I L T R A T I O N S Y S T E M S HYDROFLOW Contaminates Are Trapped Within The Cake Cellulose Filter Aid Creates A True Depth Cake Which Increases Dirt Holding Capacity And Filtration Efficiency STAR FILTER DEPTH FILTRATION MICROSCREEN SEPTUM
9 Hydroflow Filtration Systems F I L T R A T I O N S Y S T E M S HYDROFLOW The New Media Quickly “Blinds Off” Resulting In Rapid Regenerations Regeneration Cycle Introduces Small Section Of New Media Flow Takes The Path Of Least Resistance, Quickly Coating The New Section FLAT BED FILTER REGENERATION Permanent Or Disposable Roll Media
10 Hydroflow Filtration Systems F I L T R A T I O N S Y S T E M S HYDROFLOW The Entire Filter Area Is Renewed And Recoated So The Velocity Stays Low Resulting In Long Efficient Filter Cycles Increase In Vacuum Compress The Filter Cake, Restricting Flow A Gentile Backwash Of Clean Fluid Releases The Compact Filter Cake The Dense Filter Cake, Laden With Solids Quickly Settles To The Conveyor STAR FILTER REGENERATION CYCLE