Abstract
The distribution of the void fraction in the powder layer is one of the most fundamental properties in the estimation of pressure loss through the powder layer formed by filter dust collection. In this report, the void fraction of the fly ash powder layer collected on a filter paper is discussed. It was confirmed that the powder layer formed by air flow loaded dust has a distribution of the void fraction in the direction of air flow. The void fraction was 0.8 at the surface and was 0.6 at the bottom of the powder layer. The relationship between the average void fraction and the thickness of the powder layer could satisfactorily be estimated by using Kawakita's or our experimental correlations as the compression equation, and Carman's equation as the permeation equation. The effect of Knudsen flow on the permeation increased as the void fraction decreased.
