Pressure drop evolution during dust loading of hollow-fiber membranes

Pressure drop evolution during dust loading of hollow-fiber membranes

en

This work focuses on the pressure drop evolution during particle loading of polypropylene HFMs. We used two types of dust to simulate a particle laden environment. Pressure drop, permeate velocity, and accumulated mass of particles until reaching the final pressure drop were recorded. Dust-holding capacity was measured after each experiment. The pressure drop increased slowly when loaded with high dust concentrations. The membrane was easily cleanable simply by shaking, with a minimal residual pressure drop. The loading profile (pressure drop/dust load curve) varied with the inner diameter of hollow fibers and permeate velocity. The loading profile of a new HFM was independent of dust concentration, which is similar to the behavior of planar fabric-based filters. However, when a cleaned membrane was used, the dependence on the dust concentration was obvious. The same was true for the fouling rate, which was higher for the cleaned membrane than for the pristine one. Based on the results, it can be concluded that the HFMs can be repeatedly cleaned and reused, which is not possible in commercially available HEPA filters. At the same time, however, they are limited to a very specific low volume, or short-term high volume applications due to the higher pressure drops caused by the hollow-fiber geometry.

This work focuses on the pressure drop evolution during particle loading of polypropylene HFMs. We used two types of dust to simulate a particle laden environment. Pressure drop, permeate velocity, and accumulated mass of particles until reaching the final pressure drop were recorded. Dust-holding capacity was measured after each experiment. The pressure drop increased slowly when loaded with high dust concentrations. The membrane was easily cleanable simply by shaking, with a minimal residual pressure drop. The loading profile (pressure drop/dust load curve) varied with the inner diameter of hollow fibers and permeate velocity. The loading profile of a new HFM was independent of dust concentration, which is similar to the behavior of planar fabric-based filters. However, when a cleaned membrane was used, the dependence on the dust concentration was obvious. The same was true for the fouling rate, which was higher for the cleaned membrane than for the pristine one. Based on the results, it can be concluded that the HFMs can be repeatedly cleaned and reused, which is not possible in commercially available HEPA filters. At the same time, however, they are limited to a very specific low volume, or short-term high volume applications due to the higher pressure drops caused by the hollow-fiber geometry.