Filter underdrain system

Abstract From the Canadian patent

Conventional filter underdrain apparatuses present many problems including non-uniform distribution of backwash water during cleaning of the filter media inability to cope, with explosive air release designs that tend to cause, channelling jetting through the media designs that are prone, to structural failure designs that are expensive and difficult to install, designs that have no flexibility in terms of capability to operate with air scour assisted backwash or simultaneous air scour\water backwash, designs that require expensive, difficult to build, false bottom structures or, require tedious grouting procedures; designs not sufficiently corrosion resistant, designs that use relatively …