Lauter Grant
One
problem I was having was compaction of the grainbed due to pump suction.
What I did to eliminate this was build a Lauter Grant to go in between
the mashtun and the pump. The LG has a float switch on it to cycle the
pump off if the level gets low, and now the wort flow is completely by
gravity flow with the pump returning the wort to the top of the mash.
The LG is made out of a 2 gallon stainless stockpot.
You can see that I've added a high limit float switch. When the wort hits the float, it closes the solenoid and stops the
wort flow. The solenoid used for the grant is a Granger #3A434, which has the same body as the others,
but a slightly different diaphragm that allows it to open under zero flow. The grant is then pumped down until the low limit is reached, after which the solenoid
is opened to wort flow again. The pump only runs when pumping down the grant. The "Y" strainer you see
inline with the valve is used to bypass the solenoid for the first few cycles to eliminate grits in the piping.
The screen element has been removed, and I just take the cap off of the bottom and run the wort through a screen
that fits over the grant.
Pump Selection
I originally used a Teel pump rated for 180F, but I've sinced switched to a March pump
rated for 250F which was purchased from McMaster-Carr
I originally used the #5C203 speed control from Grainger, which works like a
charm as long as you leave the pump on. I had problems with it stalling on startup,
so I have a ball valve controlling the flow now. Most of the time I leave it wide open anyway.
Concept