Optimising flow rated from Mash tun

[Brewberosa]

I am helping break in a new mash tun. I want the run off to be fast as possible to speed up the brew day but slow enough not to collapse the mash.

How has anyone in the past found the sweet spots? Trial and error can get a lot of stuck mashes or needlessly long brew days.

[Brewberosa]

I was hoping for something along the lines of a practical use for Darcy's Law...

[cpelz]

I've been giving some thought to this myself recently. I found Dave Miller's article particularly informative (and I've been reading a lot of different sources.) He's writing for homebrewers, but references his experience on pro systems. He says: "Years ago Prof. Narziss of Weihenstephan suggested that initial wort velocity should be no higher than 7.3 mm/min. (.29 in./min.)" This figure and your mash tun area will give you a gpm which Miller considers a "best-case maximum".

I also found this article by Van Havig helpful when setting mill gap.