Air Distribution Screens
Over many decades HEPA/ULPA/PTFE filters have been asked for with shapes requiring “other than 90 degree corners”. Such filters have been attempted by various filter vendors, without much success, as the filters are hard to consistently seal. At present no top drawer HEPA/ULPA/PTFE manufacturer will agree to build a filter that does not have 4 ea equal 90 degree angle corners, meaning all filters can only be square or rectangular.
So, what do you do when the clean zone is non-rectangular, or possibly larger than the FFUs filter?
Simple. Add to the design an air distribution screen, which provides a secondary plenum that allows clean air to “spread out” uniformly to match your clean areas shape and size.
The following presentations show you how they work conceptually, how they are constructed, and some test results using the screens with varying secondary plenum depths and different screen materials.