(293d) A Predictive Pressure Drop Model For A Multi-Filter Array Filtration System

Sothen, R. A. - Presenter, Auburn University

Adsorbent or catalyst entrapped media, such as microfibrous materials engineered at Auburn University, provides a novel method to efficiently entrap particles as small as ten microns within a sinter-locked matrix of fibers. The small adsorbent diameters greatly increase the contacting efficiency of the media; however, the particles also increase the pressure drop across the media due to additional drag. The increase in pressure drop is a limiting factor of the media's capacities. If a thick media is designed to increase adsorbent loading, the resulting rise in pressure resistance will drastically increase energy consumption and could potentially overload the air handler.

Pleating the media is a simple approach to increase the capacity and reduce the pressure drop of the filter. A second technique to greatly increase the capacity and further reduce the pressure drop is to employ a filtration array composed of multiple pleated filters. To fully utilize the potential of the filter array, a comprehensive model of pressure drop factors is constructed. By employing various fundamental fluid dynamics equations and empirical data, the research establishes a predictive model capable of estimating pressure resistance for flow through a multi-filter array. The contributions of filter count, pleat count, filter depth, and media type on total pressure drop across the system is assessed.

Using this model, the capacity and contacting performance of a multi-filter array is compared to a packed bed at a fixed pressure drop and volumetric flows. Through the use of novel material and packaging techniques, the amount of adsorbent present in a filtration unit can dramatically increase while maintaining a lower pressure drop than commercially available adsorbent units.