Effect of particle loading on hte collectin performance of an electret cabin air filter for submicron aerosols

摘要

Electret filters are composed of permanently charged electret fibers and are widely used in applications requiring high collection eficiency and low-pressure drop.We tested electret filter media used in manufacturing cabin air filters by aplying two different charging states to the test particles.These charging states were achieved by spray electrification through the atomization process nad by bipolar ionization with an aerosol neutralizder,respectively.Polydisperse solid NaCl particles with 0.1%,and 1% solutions or liquid dicotyl sebacate (DOS)particles were generated from and atomizer,and they wedre laded on the filter media.The amount of charge,the mean particle size,nad the particle material significantly affected the collection performance of the electret filter media for submicron particles.The collection efficiency of hte electret filter media degraded as more particles were loaded,and showed minimum efficiency at steady state.The electret filter media captured the gighly charged particles more effciently during the transient state.At steady state,the filter media laded with smaller NaCl particles showed lower collection efficiency.The filter media loaded with liquid DOS particles showed collection efficiency much lower than those loaded with solid NaCl particles.