Deep bed filtration of liquid suspensions in the multilayer fibrous structures

The time dependencies of filtration efficiency and pressure drop of a model fibrous multilayer filter in which either packing density of fibres or fib re diameter change with the distance from the inlet were studied. Theoretic al analysis of a nonsteady-state filtration in fibrous filters indicated th at the highest dust capacity of filter, for assumed filtration efficiency a nd pressure drop, was obtained at constant porosity for all filters' layers and for decreasing fibre diameter along the suspension flow through the fi lter. Tubular filter with such a structure was produced in a melt-blown tec hnology. Experimental measurements of filtration efficiency, pressure drop and dust capacity confirmed the theoretical prediction.