Originally Posted by Bobby_M
The weirdest thing is that I kept meaning to post a request for MLT sparge ring/ RIMS return method examples. The requirements I have are height adjustability for various grainbed heights and it being able to deal with particulates and not get clogged. I want it to be installed while mashing obviously and need it to be easily removable.
What I eventually came up with (in my head so far) is to put a weldless bulkhead in just under the top skirt of the keg and put a male QD on both the inside and outside. The female QD on the inside would be an elbow with hose barb and I'd put about 3' of silicone tubing on there. The tubing would have a bunch of 1/2" long slits cut all down the length and the end would be plugged.
That is vaguely like mine, but I think your's sounds a bit better.
I drilled a hole through the top skirt of my MLT and put a copper tube through it. On the out side is a male QD, and on the inside is a three-way valve. One output of the valve routes to a fixed copper ring manifold that I installed just under the curved upper rim of the 12 inch diameter opening in the top of the keg. The copper recirculation return ring has 9/64ths inch holes drilled in it every inch or so.
The other output of the 3-way valve goes to a short length of pipe that terminates in a 1/2 inch hose barb. I connect a short length of silicone hose to the barb, then to a similar barb mounted via a compression fitting to the top of one of those stainless rotating sparge arms that I mounted through the middle of my MLT lid. I cut a window in my MLT lid so I can monitor flow and water level for either the recirculation return manifold or the sparge arm.
I used it for the first time this past weekend and I learned some things. First, my sparge arm has about 7 inches of height adjustment, but it doesn't really need it. The sparge water is so fine coming out of it that it doesn't disturb the grain no matter how far it falls, especially since I kept 1 to 2 inch of water above the grain. Second, my fixed copper manifold goes all the way around the keg just under the top opening. I could go six or eight inches and it would do as well at the low recirculation flow rates I'm using. I didn't notice any significant grain bed disturbance caused by the fixed recirculation manifold, even though it is a fair distance above the grain. The 9/64th holes I drilled are a little small. Grain that got through my false bottom tended to clog them. I need to drill them out to 5/32nd or turn them into slits instead of holes, and maybe shore up my false bottom. It seems like a lot of grain was getting through.