GridBLOK - Gas-Phase Air Filtration Brochure

| | | | | | | | | | | | | | | | | | | | | | | |ADVANCED CHEMICALAIR F ILTRATION I I I I I I I I I I I I IC L E A N A I R S O L U T I O N S 4 A D VA N C E D C H E M I C A L A I R F I LT R AT I O N For over 40 years, Purafil has been the world leader in the designing, engineering, and manufacturinggas-phase air filtration media, filters, systems and air monitoring instrumentation. Historically, the premise ofgas-phase filtration revolved around various sized and shaped pellets. Purafil, the industry leader, created arevolutionary delivery system – the GridBLOKTM technology. The Purafil GridBLOKTM delivery system is thefoundation for the next generation of gas-phase air filtration products.The GridBLOK™ is a new gas-phase air filtration medium in the form ofan extruded monolithic block consisting of a large number of smallstraight and parallel cells or channels. The GridBLOK™ is composed ofessentially 100% adsorbent materials allowing the entire compositestructure to function as a gas filter.Due to the large number of cells in each GridBLOK™, the contact areabetween the adsorbent layer and the airstream that travels inside thecells is very large. Furthermore, the cells are straight and parallel so thatthe flow is not obstructed and the pressure drop across the GridBLOK™is extremely low.The cellular geometry of the extruded GridBLOK™ provides a high surfacearea per unit volume important for proper impregnation of adsorptivematerials. The size of the cells leads to turbulent flow and forcescontaminated air into and through the gas-permeable cell walls of theGridBLOK™. It also provides the residence time necessary to assureoptimum contact efficiency and the associated high initial and averageremoval efficiencies. As the air is forced through the GridBLOK™, removalof chemical contaminants takes place.NbNOBYPASSlPdLOW PRESSUREDROPSsSELFSUPPORTING1 2 3A primary role of Purafil’s R&D program is to continually develop new delivery systems for our dry-scrubbing air filtration media and products. The Purafil patent protected GridBLOK™ delivery systemis the foundation for the next generation of gas-phase air filtration products. The innovative GridBLOK™delivery system will successfully integrate into Purafil’s Family of Products.Features and Benefits:• No bypass – all of the air goes through the filter• Low pressure drop – provides for energy savings• Turbulent flow – cell geometry provides high contact efficiency with contaminant gases• Composite structure – fully available for adsorption with impregnations for specific gases• Full utilization of the media – removal efficiences and capacties comparable to granular media• Self supporting – provides structural stabilityG r i d B L O K ™ O V E R V I E WThe size and shape of the cells in the GridBLOK™ lead to turbulent flow assuring a constant velocity profile in all internal parts of the cells. Theexception is the thin layer of gas at the cell wall, in which the flow velocity sharply increases from an almost zero value. As the gas velocity increases,it is in this region where the flow begins to change to turbulent flow. It is this turbulent flow that ensures the GridBLOK™’s superior performance.T U R B U L E N T F L O WThe flow of air through a self-supporting grid structure can be either laminar or turbulent (Figure 1). Laminar flow of gases can only be maintainedup to a critical mean velocity, because at higher velocities turbulent flow begins. Monolithic structures have straight flow paths with very small celldimensions and, in many instances, the flow through the channels is laminar, which offers advantages such as low pressure drop. However, laminarflow also means that there is very little mixing of the airstream during the flow through the grid structure. As a result, the contact efficiency betweenthe grid’s surface and the contaminant(s) to be removed may be very low with a corresponding low removal efficiency.The turbulent flow of gases is the most widespread and also the most complex form of fluid movement through a monolithic structure. The flowof gases and air through the GridBLOK™ delivery system is distributed in such a way that there is great friction between the wall and the flowinggases. This enhances gas filtration performance due to the turbulence causing extensive and continual mixing across the airstream. More of thegas molecules contact the walls of the channels and more efficient gas removal is the result.Figure 1M AG N I F I E D V I E W O F T H E G r i d B L O K ™ C E L L U L A R S T R U C T U R EGridBLOK VERSUS GRANULAR MEDIAVarious gas-phase air filter designs using granular adsorbents in commercial applications strive to make the large internal surface area (porosity) of themedia accessible to a moving airstream, or more accurately to the undesireable gaseous contaminants in the airstream, so they may be removed. Thebetter the efficiency of the design in doing so, the better the adsorbent will be utilized.In packed beds of granular media all of the surface area may not be accessible due to airflow patterns that develop because of non-uniform sized particles,settling of the media bed, etc. Also, the adsorbent particles have to be of a sufficiently large diameter to provide a manageable pressure drop which canalso prevent full utilization of the adsorbent. When these same adsorbent materials are made available in the GridBLOK structure, the adsorption capacitycan be better utilized and a more efficient filter design is the result. Further, the velocity profile through the GridBLOK is almost constant in all parts ofthe cell which provides for a pressure drop significantly lower than a 1” bed of granular media (Figure 2).Of the parameters that Purafil can control during the GridBLOK™ manufacturing processes, cell dimension, wall thickness, and cell shape have beenoptimized for high gas filtration performance. Due to this manufacturing flexibility and the ability to independently manipulate these geometric parameters,the opportunity also exists to further optimize the design for more specific applications. Design flexibility is much more limited with granular materialsdue to the requirement for a separate delivery system (e.g., trays, modules) and having to balance pressure drop versus particle size.It is desirable to obtain high gas removal efficiencies from small bed volumes. In the GridBLOK™, the structure of the cell walls optimize the open areafor air flow thereby increasing residence time, while increasing the contact efficiency between the contaminant(s) to be removed and cell walls. Due tothe high rate of contaminant diffusion to the interior of the cell wall and empty sites being continuously available for adsorption, the GridBLOK™ providesbetter adsorption efficiencies and capacities than prior attempts with monolithic structures.Adsorption efficiency will depend on how efficiently the molecules come in contact with the cell walls, which is determined by wall thickness, gas flowrate and concentration as well as by the size of the pores relative to the contaminant molecules. Initially, all the available adsorption sites are vacant andso all the gas molecules are being adsorbed. At the same time, these molecules begin to diffuse inside the cell wall. As more surface sites become availabledue to diffusion to the interior, more adsorption can take place. The walls of the GridBLOK™ structure allow rapid diffusion of gases through the walls totake advantage of the large internal surface area and provide the maximum removal capacity possible.Figure 2AIR SCRUBBING:There are currently four types of GridBLOK™ available: The Purakol® GridBLOKTM, the Puracarb® GridBLOKTM, Puracarb® AM GridBLOKTM, and theChlorosorb® GridBLOKTM. Just as their granular namesakes, they are effective against a number of gaseous contaminants and can be combined toprovide the best performance in a wide range of applications. The performance of the GridBLOK™’s monolithic structure-based system is comparableto, and in some cases superior to, traditional packed-bed media systems. Combine these media choices with low pressure drop, and performancecharacteristics and you now have a superior option for controlling gaseous contamination.The GridBLOK i s ava i lab le in the fo l lowing MEDIA compos i t ions :PURACARB® -Manufacturedspecifically forcorrosiveenvironments andremoval of acidgases, includinghydrogen sulfideand sulfur dioxide,in industrialsettings. PURACARB® AM -Used specifically forthe control ofammonia andamines.PURAKOL® -Used in combinationwith other Purafilmedia to ensurebroad-spectrumremoval ofpollutants.1 2 3 CHLOROSORB® -Manufactured withenhanced capacityfor removal ofchlorine.4I N D E P E N D E N T T E S T I N GIn spite of the open structure of the GridBLOK™, it has been proven to exhibit breakthrough curves similar to packed beds. This behavior can beexplained in terms of dynamic equilibrium between adsorption and diffusion of the adsorbate molecules into the cell walls.The GridBLOK™ was submitted to an internationally recognized independent research institute to evaluate its performance relative to traditional 1”packed beds of granular dry-scrubbing media and experimental data have been obtained using dynamic flow apparatus (Figure 3).Figure 3© Purafil 2009 Tech Brchr--GridBLOK-01ISO 9001:2008 2654 Weaver Way Doraville, Georgia, 30340, U.S.A. tel: (770) 662-8545 (800)-222-6367 www.purafil.comM AG N I F I E D C E L L U L A RS T R U C T U R E V I E W O FT H E G r i d B L O K ™ I N S I D ET H E P u r a G R I D ™ F I LT E RPuraGRID™ Filters (IP units)Filter Type Filter Size, in.PuraGRID 2”PuraGRID 2”PuraGRID 2”PuraGRID 2”PuraGRID 2”PuraGRID 4”PuraGRID 4”PuraGRID 4”PuraGRID 4”PuraGRID 4”24202016122420201612Exact Size, in. GridBLOKDensity27.5427.5427.5427.5427.5427.5427.5427.5427.5427.54Media Amountper Filter53344437029626613531127940752676Frame Material Airflow PressureDropGalvanizedGalvanizedGalvanizedGalvanizedGalvanizedGalvanizedGalvanizedGalvanizedGalvanizedGalvanized5005005005005005005005005005000.290.290.290.290.290.580.580.580.580.58242520202424252020242222244444w h d w h d23 3/819 1/219 1/215 1/211 3/823 3/819 1/219 1/215 1/211 3/823 3/824 1/219 1/219 1/223 3/823 3/824 1/219 1/219 1/223 3/81 3/41 3/41 3/41 3/41 3/43 3/43 3/43 3/43 3/43 3/48.57.15.94.74.221.618.015.012.010.82000173613891111100020001736138911111000The PuraGRID™ is a revolutionary new filter that is designed to supply a largeamount of chemical filtration with minimal amount of pressure drop. Ournewly developed media delivery system offers increased operationalperformance and energy savings. The new PuraGRID™ bridges the gapbetween Purafil’s existing line of filtration products, enabling a clean airsolution for every application and market.lb/ft3 in3 lb fpm cfm i.w.g.PuraGRID™ Filters (metric units)Filter Type Filter Size, in.PuraGRID 2”PuraGRID 2”PuraGRID 2”PuraGRID 2”PuraGRID 2”PuraGRID 4”PuraGRID 4”PuraGRID 4”PuraGRID 4”PuraGRID 4”610508508406305610508508406305Exact Size, mm GridBLOKDensity0.44110.44110.44110.44110.44110.44110.44110.44110.44110.4411Media Amountper Filter873072756063485043652217018475153961231711085Frame Material Airflow PressureDropGalvanizedGalvanizedGalvanizedGalvanizedGalvanizedGalvanizedGalvanizedGalvanizedGalvanizedGalvanized2.52.52.52.52.52.52.52.52.52.573737373731461461461461466106355085086106106355085086105151515151102102102102102w h d w h d594495495394289594495495394289594622495495594594622495495594444444444495959595953.93.22.72.11.99.88.26.85.44.93398295023601888169933982950236018881699g/cc cm3 kg m/s m3/h Pa| | | | | | | | | | | | | | | | | | | | | | | |