(558f) Utilization of Microfibrous-Supported Sorbent Materials and Novel Packaging Designs for Improved Indoor Air Quality at Reduced Energy Consumption

The demand for improved air filtration due to poor indoor air quality (IAQ), potential threat of biological outbreaks, and increasing control standards in industrial applications has created a need for medium efficiency particulate air filters combined with a gas phase sorbent/catalyst scrubber. These dual-functioning materials excel at removing airborne pollutants such as dust, formaldehyde, and volatile organic compounds (VOC's) that are commonly sited to cause and aggravate asthma, allergic reaction, cancer and other respiratory diseases. The increased filtration performance, however, comes at a price. Dual-functioning materials have substantially higher flow resistances than traditional filtration media due to the decreased fiber diameters, tighter packing densities, and presence of adsorbent/catalyst particles. The utilization of these filters results in a significantly higher energy consumption; thus, these materials can become price prohibitive due to their considerable pressure drops.

Improvements to current filter designs must be made in order to successfully employ a dual-functioning media at a reasonable cost. High resistance media are commonly housed in a pleated filter. By folding the media into a corrugated arrangement, the face velocity and subsequently the pressure drop across the material is reduced. Multi-Element Structured Arrays (MESA's) represent a new approach that expanses on the pleated filter's premise. MESA's consist of numerous pleated filters mounted into a single, corrugated arrangement to further reduce the face velocity and pressure drop across the system. This unique arrangement has been demonstrated to incorporate four times the available media area into a filtration unit while operating at one-third the initial flow resistance of a traditional pleated filter.

The current study investigates the utilization of microfibrous-supported sorbent materials (MSSM) for use as a dual-functioning media. MSSM achieve high adsorptive rates and sorbent utilization by entrapping small (< 200 microns) activated carbon particles within a matrix of polymeric fibers. The fibers double as a particle filter capable of removing 50% of airborne particles as small as 0.5 microns. The filtration performance of the MSSM media were evaluated and compared to traditional filtration materials by investigating the following parameters: initial permeability, removal efficiency, aging characteristics, and breakthrough time. Based on these measurements, a MESA filter unit composed of MSSM media could be modeled for lifetime energy consumption and useful working time.