missing link said:
I just tried using a rotating sparge arm for the first time. The bottom of my HLT was about a foot above the top of my MT. In order to get the arm to spin I had to flow so much water that I used all my sparge water in 10 minutes instead of 60. How do you guys get a 60 min sparge using the roatating arm? I was sparging almost 6 gallons of water.
Linc
Don't get too hung up on the sparge arm spray when conducting fly sparging.
It seems experts agree that a level of about 2 inches of water above the grain bed is most important.
Think about what fly sparging is trying to accomplish; slow perculation of sparge water down through the grain bed. It's REALLY slow; most sources indicate about a 1 QUART per MINUTE. (That's freakin' slow.) Like about a pencil-sized diameter out of your kitchen sink water faucet, probably less.
Sparge spray arms are attempting to enusre that the sparge water heat is evenly distributed in a vertical fashion as it flows down through the grain bed.
You would have to create an extreme situation in fly sparging at the above rate (1 qt./min.) for this NOT to occur. Kinda' like peeing in one small spot in a toilet bowl. Just don't concentrate the sparge water out of a hose at too great a rate into one small location in the mash tun, and fly sparging will work well without the sprayer.
Measure the fly sparge rate; go ahead ! Shoot for about 1 qt./min. and use a piece of heavy aluminum foil on top of the mash (with many holes) to distribute the sparge water over the top surface of the grain. Just get that 2 inch depth on top of the grain, even out the inflow and outflow to the mash tun, and fly sparging will help you achieve better efficiencies.