Testing of Recleanable and Sustainable Metal Media Filters

摘要

Many types of filter media, ranging from single use (deposable) to semi-permanent, are utilized today forrnseparation of particular matter in industrial filtration applications. Semi-permanent media are usuallyrncleanable, either on or off-line, and are intended for sustainable, often multi-year, operating life. Sinteredrnmetal powder media are semi-permanent media that provide excellent performance for demandingrnsolids/liquid separation and gas/solid separation processes found in the chemical process, petrochemicalrnand power generation industries. Applications require particulate removal to protect downstreamrnequipment, for product separation, or to meet environmental regulations. Sintered metal media haverndemonstrated high particle efficiency removal, reliable filtration performance, effective backwashrncapability, and long on-stream service where other media often are not a cost-effective solution. Alongrnwith the filtration efficiency consideration, equally important criteria include corrosion resistance,rnmechanical strength at service temperature, cake release (blowback cleanability), and long on-streamrnservice life. These issues are critical to achieving successful, cost effective operations.rnThis paper will discuss the basic approaches used for media selection and testing to ensure successfulrnimplementation of porous metal media in sustainable (cleanable) filter operation. Selection of thernappropriate filter media starts with an evaluation of the process requirements. Proper media selectionrnrequires appropriate knowledge of the media, fluid, and particle properties. Fluid properties include fluidrnvelocity through the filter media, viscosity, temperature and pressure, and corrosive nature. Selection ofrnspecific media grade requires an understanding of the particle properties such as particle size, shape,rndensity and stickiness. For example, catalyst particulate matter of the same type can produce totallyrndifferent filtration results. Attrition of the catalyst will also affect overall filter performance. Media testingrnbegins with a simple disc test to qualify media and determine filtration characteristics. More advancedrnbench-scale and pilot scale testing is then used to verify filter-operating parameters for scale-up design ofrna commercial filter system. Experimental data will demonstrate the effect of particle size on filterrnperformance. Also included are guidelines for filter scale-up design regarding operating parameters andrnrecommended filter housing configuration using different particulate materials.