Influence of the surface roughness of grit-blasted steel on the wall friction angle of limestone powder
C. Lanzerstorfer, B. Huber - Influence of the surface roughness of grit-blasted steel on the wall friction angle of limestone powder - 14th Minisymposium Chemical and Process Engineering , Linz, Österreich, 2018, pp. 1-4
In the engineering of powder storage, handling and conveying equipment friction between the powder and the wall material always has to be considered. In this paper the influence of the surface roughness of structural steel on wall friction is investigated. Different values of the surface roughness of the wall material were obtained by applying different grit blasting procedures. The wall friction with four different types of limestone powder was measured using a ring shear tester. Correlating the parameters of the wall material and the powder with the measured wall friction angle the influence of the various parameters was investigated. The results obtained for the wall friction angle measured by shear tests show a clear influence of the parameters of both the wall material and the powder on wall friction. Generally, the wall friction angle is smaller at higher values of the wall normal stress. Also a higher value of the mass median diameter of the powder leads to a smaller wall friction angle. In contrast, higher values of the average surface roughness, the gradient angle of the surface roughness and the spread of the particle size distribution result in increased wall friction.