DIY flow guage for sparging

Just been dabbling around with the brewery and and made a flow measuring device out of a few copper fittings and a bit clear tube thought I would share.



The basic idea is a simple manometer connected to the sparge line so that I can monitor the sparge rate without taking the lid off the Mash tun.

I borrowed this idea from Bernoulli who was a mathematician in the 1700s. :thumb: Basically he said that "In fluid dynamics, for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy."

What that means is that if you reduce the diameter of a pipe, for example through a nozzle, a change of pressure can be recorded corresponding to the pressure and hence flow. He actually says lots more but lets not get bogged down in fluid thermodynamics :nono:

The easiest way to build a DIY nozzle is with a few copper fittings these are 15mm and 8mm



Solder them together.



and there you have a home made nozzle with tubes for the manometer, which looks like this when you put it together:



The tube is extended vertically so that the pump doesn't simply fill your manometer tube up.

The scale is horizontal lines 1cm part used for reference only.

All you need now is a measuring jug and a watch with a second hand. Simply set the pump flow rate using whatever control you have, (I use a bypass valve and speed controller) and note the difference in the manometer levels in cm then measure the flow into a jug over 1 minute.



Repeat this for various flow rates and plot a graph if you like. I have just made a note on the side of the manometer.

My sparge arm stalls at around 0.85 litres/min due to friction in the make shiftbearing but that is low enough to satisfy the rate I am looking for.

Looks good, but a simpler (ok smaller) system could be set up using a liquid flow meter and an Arduino, which would give you a digital readout. Ok you need to have/get an Arduino unit, but they have lots of other uses, and the flow meter costs about £13, so probably not too much more than all your plumbing bits. Have a look HERE And the forum thread: HERE Which gives you the code.

That's £13 plus more than the manometer cost! : I think the flow meter route is the way to go, although I am not sure I have the measure of the Arduino. Is anyone using the arrangement? :thumb:

Hi.

Nice sparge arm, I was thinking of making myslf another to take over from my "Phils Sparge Arm" and was wondering how you had designed and managed to keep the joint free to spin ok.
It looks in the photo like a straight compression connector, does it spin ok just left slack or is it more techie than that?

The sparge arm is made of three pieces of 8mm copper tube soldered into an 8mm end feed tee. Two of the pieces are blanked with 8mm end feed caps and the third is used to take the provide the pivot via an 8mm compression connector. :thumb:

The trick seems to be tighten the coupler fully so that the olive is secure on the sparge pipe end (bottom) of the coupler, then undo the nut from the bottom end and wind 10 or so turns of PTFE tape around the thread so that when you replace it you don't have to tighten it fully and it will spin freely on the olive. If you want to get really clever with it drill the holes so that the sparge arm spins anit-clockwise and it won'ttend to unscrew itself and fall into the mash like my first one did :lol:

I can get a flow rate as low as 0.8 Ltr/min before the sparge arm stalls due to friction but I start off with a greater flow to overcome the inertia and then slow it down. :thumb:

I confess to a lot of messing about with hole sizes and spacings before I got it to work well and distribute the sparge water evenly. You will find that you need more holes closer to the tee as centrifugal force tends to play a part. The holes closer to the end of the arms provide most of the turning force (torque), so its a bit of a balancing act.

There are 7 holes in my sparge arm about 1.8 mm in diameter but I don't have an exact hole size as they are made with a ground down 1/8" bit. :grin:

Good luck :drink: