Spinning sparge arm. What do I do with it?

cnelsonplumber said:

When you are circulating your wort through your HERMS, I suggest you dont use a sparge arm or spreader. The reason for this is that you don't want to aerate the hot wort.

I used to do this and got some undesirable flavours and I definitely get better results by returning the wort to the MT just below the level of the wort.

I remove my 8mm sparge pipe from the connector it spins on and use a piece of 8mm tube with a bend in so that it doesn't drill a hole in the mash and place the free end just below the surface the wort.

Introducing air to the wort is good for the yeast but only after is cooled to below 26C or there abouts.

Click to expand...

Do you use sparge arm/wort spreader once you start sparging? I was thinking it would be fine as it's only water at that stage - but then thought, does it create too much splashing leading to aeration of hot wort, and therefore would be better to avoid? :hmm: :wha:

Dennis

I think the holes in mine are slightly to big and maybe to many, i can get it to spin quite fast on full tilt but it is sparging to quickly..if i slow down the flow then it just stops and dribbles...how many holes did you drill and what size, i think i used a 1mm drill and have about 6 on either arm.

How do you lot so accurately measure your flow rates? :wha:

evanvine said:

How do you lot so accurately measure your flow rates? :wha:

Click to expand...

Low flow rate and spin has been like the holy grail quest, but I did achieve 3/4 ltr per min after about 20 variations on the spinny sparge arm theme. Funnily enough I now batch sparge.

To measure accurately the easy way is to put a measured quantity of liquid (at the right temperature and viscosity as it makes a big difference) into a graduated vessel and use this as a reservoir to draw from. Say 10 ltrs or more.
Get everything warmed up and settled down then make a note of how much is in your graduated vessel (ltrs.) and start the stop watch.
Let it run for as long as possible then stop the watch and note the finish volume in the vessel.

Now for the maths:

Subtract the finish vol. from the start vol. Then divide the result my the number of minutes to get the average
If you want to make the maths easy stop the watch and measure the finish vol on whole minutes

I am betting that it will be a struggle to get below 1.25 ltr per min.

Thanks CNP, but was rather hoping you had some natty little device.
OK then, back to basics, an old friend of mine!

evanvine said:

Thanks CNP, but was rather hoping you had some natty little device.
OK then, back to basics, an old friend of mine!

Click to expand...

It took me months of different materials and hole sizes to get mine to work

Friction is the killer on the bearing, so I went for the lightest material I could find which was thin wall 8mm stainless tube and used 8mm end feed copper fittings, with the pivot as an 8mm brass coupler which I modified painstakingly with a swiss file to give the narrowest possible bearing surface.
Balance is the next area too look at, if the arm is not well balanced it will not spin true and pull the bearing.

Hole size is the biggest issue possiby as you want to achieve just enough inertia to spin the arm and no more.

I found that the size of the holes and the spacing between them increases as distance increases from the centre. Dont want to get too deep into thermodynamics here but basically you get less useful turning effect close to the centre.

The holes further from the centre also tend to throw the sparge water to the outside of the MT so you need to angle them back in.
Just whem you think you have got it then you find that you need to have the inner holes angled further down than the outer ones.
Hence why I batch sparge.

If you are going to experiment try using plastic straws as the ends can be tied with cotton and blue tacked into an 8mm tee. This will save a fortune and get you in the ball park.

Ebay sell a set of model makers twist drills from 0.25mm to 1.0mm or something like that which are invaluable.

I could produce a commercial sparge arm with ease, but at sparge volumes around 18 ltrs it is a challenge for home brew.

Good luck

Think I may look to batch sparging. With my spinny I seem to just keep stopping and starting it whilst maintaining an inch of water on top of the grain bed and standing by it to keep an eye on it. I always seem to have to liquor back my brews as well. Mind you I have not for some reason been able to grt my head around batch sparging.

This isnt a spinning sparge arm but might be an idea for forum members
http://www.ebay.co.uk/itm/Sparge-Ar...755?pt=LH_DefaultDomain_0&hash=item1e822ccbf3

I have seen diy sparge arms that use a tube in a tube, then O rings to a third tube, and I also have a Phils sparge arm, that cannot possibly have all that junk inside it!
I need a bigger sparge arm, like Phils, as it has worked without fail for decades. Has anyone taken one apart to see what that tiny little bit of wire with the blob of silver solder does?
Hoping someone has already let curiosity get the better of them!
Rog,

Try a full cone nozzle . I got mine from PNR, they'll ask you all sorts of technical questions but opt for wide (120') and spiral if you recirculate. Brilliant so far.