AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Filtration of Ultrafine Dust Emitted by Biomass Combustion with a Baghouse Filter Using Precoat Materials
SASCHA SCHILLER, Hans-Joachim Schmid, University of Paderborn, Germany
Abstract Number: 13 Working Group: Combustion
Abstract To comply with the legal requirements in Germany a baghouse filter has been developed. It combines excellent separation efficiency with convenience in operation for wood-fired heaters (e.g. pellet heaters). In order to prevent clogging of the filter cloth by sticky and ultrafine particles, it is necessary to use a precoat. For this purpose different precoat materials have been analyzed (e.g. limestone powder). With this very efficient technology, extremely high separation efficiencies > 99 % could be reached in a long-term stable process. The costs of the material are negligible when it comes to the calculation of the needed mass of a private household. However, due to the large-scale quantities in the industrial sector the reuse of the precoat material can generate significant savings. Therefor, different tests were performed to reuse and mix the precoat materials several times. During these tests the filtration behavior was detected by measuring the total collection efficiency, the grade efficiency, and the pressure drop curve of the filter. In addition to that different characteristics (porosity, bulk flow properties, particle size distribution) of the precoat materials have been analyzed after every step of reusing or mixing to detect the influence of the reuse. After that the experiences made with the laboratory build-up (pellet heater, nominal output: 15kW) were used to do a scale-up for a real application (pellet heater, nominal output: 320kW). Because of the operating method of the two plants (single-line-dedusting-mode) the resulting pressure drop curves show an inhomogeneous filtration behavior. This behavior can be described with a known model from the literature. To get a better understanding of the agglomeration and the adhesion of the ultrafine dust particles and the precoat particles optical test were made with a scanning electron microscope (SEM) after separating single particles.