4. Results and discussion
4.1. Measurement results of average thickness of cake, pressure drop, and
collection efficiency
Figs. 3 and 4 show the measurement results for pressure drop and
collection efficiency which vary with the cake thickness. The inlet dust
concentration was fixed at 200 g/m3. At constant filtration superficial
velocity, the cake growth caused an increase in the pressure drop and
collection efficiency. Kvetoslav [25] and Neiva and Goldstein Jr. [26]
reported that the minimum value of cake porosity caused the
maximum level of pressure drop. From Fig. 3, the increase of cake
thickness caused the decrease of cake porosity which resulted in the
increase of pressure drop. Due to the effects of the cake thickness and
the compact structure of cake, the maximum level of pressure drop
was reached. Höflinger et al. [27] examined the effect of shear force on
dust cakes. They reported that cake thicknesswould decrease with the
movement of the dust particulates due to the large shear force.
Jeon and Jung [28] stated that the compressive stress acting on
dust particulates in a certain layer of a dust cake could be divided
into normal and shear components. They found a decrease of cake
Fig. 3. Average cake thickness versus pressure drop in different filtration superficial
velocities at fixed dust concentration of 200 g/m3.
Fig. 4. Collection efficiency versus average cake thickness for different filtration
superficial velocities at a fixed dust concentration of 200 g/m