Splitter Box

Try a dual adjustable V weir. Of course, if this is a lumpy flow you can get damming.

This shows some broad weirs. These are broad river weirs and you can adjust the height to adjust the flow.

http://en.wikipedia.org/wiki/Weir

A V-weir is similar, but has a v shaped notch in it. as the level rises flow increases and you can adjust the V angle to change the flow equation. In addition, you can raise and lower weirs to tune them to 50:50 flow ratios etc.

I have 2 weirs in my box. One v notch and one straight. The plant right now has a v-notch weir and a monitor and they constantly have to unclog the V to get accurate readings. And with solids thats going to happen. I have a v notch weir in the chlorine contact tank and am thinking that is a much better application for one than a splitter box. like you said I might get damming no matter what kind of weir I use.

But alas my problem is not just splitting the flow evenly. It is splitting it evenly while turning the direction of the water in one side of the box. (to eliminate an extra manhole.) Here is what I need. A way to split the flow and run it into 2 septic tanks while changing directions 90 degrees and not have to install a splitter box and 2 manholes.

Thank you so much for your comments!

dmarie

You create a partition in the middle of the splitter box, at half the height of the splitter box. This creates two sections at the lower part of the splitter box. You coonect a pipe from each section to the septic tank concerned. The arrival pipe carrying the wastewater arrives in the splitter box at a height above the partition.

When the wastewater arrives in the splitter box the level of waste water is above the level of the partition. The liquid then drains out of the splitter box. As long as the back-pressure from the two pipes to the two septic tanks is equal, the liquid leaves the box in equal quantities from each section and goes to the septic tank connected to that section.

You have described my splitter box! and it would absolutely be perfect if it ran in a straight line into the septic tanks. My problem is the change in directions. At first I had the water running straight out of the box and turning both pipes 90 degrees into the tanks. (big problem with solids) theoretically I need a manhole everytime I change directions, but with such a low budget and such a tiny plant I am hoping to avoid a splitter box and 2 manholes. Now my problem is turning the direction of the flow inside the splitter box and still getting an even split. (I also have elevation restrictions) I am going to bench the inside of the box to carry the water the direction I want but I still have a bad feeling about it!

I want to thank you for your comments. Lets me know I'm on the right track.

dana marie

I don't see the problem of assymetry downstream of the splitter. Provided there is a free fall over the weirs, flow is unaffected by downstream conditions. You just need to make weirs high enough so there is a free fall at maximum flow (calculate hydraulics of downstream system).

I can envisage a blockage problem with flat or V-notch weirs. Just need to clean regularly.

You might look at the Flout as a flow divider. I know Patterson NY installed several at the WWPT, including one that split the effluent flow 5 ways at once.

Check this link and fire off questions to me or the site. I have used the Flout in places where I needed to measure trickle flows.

www.rissyplastics.com/flout/

I looked at the flouts and on the website didn't see a flout for my kind of application. Maybe I don't know what I'm looking at. I need to split a flow w/solids and turn 90 degrees into septic tanks. Hopefully eliminate the need for 2 manholes. Will a flout handle solids and not clog up on all those 90's?

These will be for the most part very small flows and I am using weirs to measure and of course a partition in the middle of the box. I am trying to envision a flout but like I said measuring is not the big problem. The problem is a very low budget. Like I said I want to split the flows and run it directly in the tanks without the danger of the lines clogging up because of the 90 degree turns.

Thank you for your comment, I am now trying to educate myself on flouts!

dmarie

flout should work as long as you get a diameter larger than the size the system is fed with. As for 90 degree bends downstream from the flout the full pressure will be felt as the flout quickly sinks to the bottom and this should flush the solids out to the arms of the system..

You want the flout to reach as low as possible to scavenge the bottom of the system.

At Patterson, the effluent flow came from a very large septic tank and was split into 5 seperate tanks to dose sand filters. The effluent was clarified water, solids remained back in the septic tank.

You have a different problem; the effluent is not yet clarified. Although a Flout will split flows evenly, I don't think it will work well with anything thicker than say heavy cream. In this case, I would use a grinder pump to break up the solids and then force everything into the bottom of the splitter box. The increased velocity would make the box you have divide the flow evenly to each tank. That's about the only way I can think to make this work without a differance in height to power the flow division in the splitter box.

I have used the Flout to turn a trickle flow into a flood strong enough to run a cheap paddle wheel flow meter on pH neutrailization systems. It has worked well and is very dependable.