NIRE-170-1-6
3
(1) Shape of Element
The membrane element is a flat sheet type as shown in Fig.I-4. At the normal filtration
operation, the sludge accumulated on the membrane surface is cleaned up effectively with
upward water stream generated with the scouring air supplied from the air diffusers installed
at the bottom side (Fig.I-5). This mechanism ensures stable filtration, since the membrane
does not easily admit of sludge adherence to its surface.
In addition, thin membrane element makes it possible to have higher membrane packing
density in the module similar to that of hollow fiber membrane, and also to improve
membrane cleaning efficiency thanks to vibration of elements by scouring air.
Fig. I-4 Structure of Element
Fig. I-5 Filtration Principle of Activated Sludge
Air
diffuser
Element
Filtrated water
Activated sludge particle
Membrane
Air
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