AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Ash Loading Behavior on Sintered Metal Fiber Filter Media at Elevated Temperature
QISHENG OU, Matti Maricq, David Y. H. Pui, University of Minnesota
Abstract Number: 377 Working Group: Control and Mitigation Technology
Abstract Filtration is considered as the most economical control technique to effectively remove airborne particles in nanometer size range. Many filtration systems are operated at high temperature, such as in advanced coal power plants, engine exhaust after-treatment, and chemical and petrochemical processes. Besides the conventional fabric bag and ceramic filter media, metallic filter media is seeing more applications because of its high porosity and strength, good thermal resistance, and good optimization between efficiency and back pressure. Besides post cleaning, pulse or backflush cleaning, some of filter media can be thermally cleaned by high temperature, such as engine exhaust filters. However, unburned ash cannot be removed by this method and can accumulate and cause a rise of back pressure.
In this study, laboratory-generated ash nano-particles are loaded onto flat sheet sintered metal fiber media, and its pressure drop evolution over ash loading are characterized under constant and varied temperature profiles. The sintering behavior of ash particles within metal fiber matrix is characterized by scanning electron microscopy, and its effect on filter backpressure and efficiency are evaluated using aerosol methods. Factors affecting the sintering and loading process are studied, including ash particle composition, primary particle size, loading rate, media characterization, test temperature and temperature evolution profile. A semi-empirical model is developed to predict the backpressure and efficiency of an ash-loaded filter media undergoing sintering at different temperatures. Good agreement is found to our measurements. The applicability of the model and the implication of the test results on ash accumulation on metal fiber based automobile engine exhaust filter will be discussed.