Flow Resistance in Filter Cakes Due to Air

The objective of this work is to show that air bubbles can adversely effect the performance of pressure filtrations. The effect of air on liquid flow resistance is measured in a well-characterized filter cake of Lucite particles. Air is introduced into the cake by allowing air bubbles to become entrained with the particles in the slurry at the start of filtration. Filtration with entrained air bubbles is compared to filtration without air bubbles. Experimental measurements show a significant increase in flow resistance due to the presence of air in a pressurized cake filtration. The presence of air bubbles in the filter cake can result in misinterpretation of experimental data. This in turn can increase operating and experimental testing costs and complicate efforts to predict filtration performance.