How has UV disinfection changed since its humble beginnings nearly 100 years ago? Well I’ve just found out so I’ll be happy to pass on my newly found wealth of knowledge.
From the empty cylindrical chambers (excepting the UV lamp) that have been around from Ye Olde Times, the newest addition to UV flow technology is the flow plate. Basically, as far as I can tell it’s a cross sectional barrier with tons of tiny holes in. Because the surface area of the holes add up to equal the input/output holes sizes, pressure and flow rate are unaffected. There is still a hole in the centre of the plate for the lamp to fit through but the water passing through this hole will get the full brunt of the UV lamp so it’s ok.
What would happen without a flow plate is that water will try taking the fastest route through the chamber. The ‘faster’ water is what is measured for treatment, not a bad thing. It just means that water that falls out of this fast stream will get over treated, a lot. With a flow plate, because the whole stream is interrupted, a lower power lamp can be used because the vast majority of water will be exposed to an equal amount of UV light.
On this picture, tracked water molecules are shown as lines. They have been followed and their routes plotted to show exposure levels to the UV. I don’t have a picture to show what it would look like without a flow plate installed but I know it would have a big thick dark blue line (Low exposure) running right down the middle that would show the fast water. Very light blue/turquoise (High exposure) light would be everywhere else just hanging around.
I think this is a good thing but to date only a few manufacturers that use flow plates, why? It’s probably a bit more fiddly and expensive to install a flow plate and a certain amount of research needs to go into knowing what the water will do with one installed, something that’s patented. On top of that, the old design works, so why bother with a new one? I would argue that innovation is what makes us human, don’t fight it man.