Transferring "trickles" via pumps during fly sparge?

I am in the early stages of planning out a single-tier system and I want to fly sparge like I currently do. I am trying to conceptualize how to transfer around the controlled flow to the sparge arm and the trickle from the MLT to the boil kettle. I currently only use the pump for transferring at a good flow from the brew kettle through the plate chiller to the carboy. I haven't even tried it yet but is there any special type of trick that you all recommend to get the pumps to transfer at the extremely low flow of a sparge?

I keep the "in" side of the pump wide open (important) but the "out" side has a ballvalve that I can slow to get the flow that I want.

Ok, I have that type of setup. When I think about it further I guess it's really the flow in and out of the pump from the MLT to the boil kettle is the one that stumps me. Do you let the trickle backup from the MLT to the pump inlet and then have it controlled flow into the kettle? Or does it not matter and the pump will handle the tiny amount of liquid going to the intake regardless?

worldzfree said:

Ok, I have that type of setup. When I think about it further I guess it's really the flow in and out of the pump from the MLT to the boil kettle is the one that stumps me. Do you let the trickle backup from the MLT to the pump inlet and then have it controlled flow into the kettle? Or does it not matter and the pump will handle the tiny amount of liquid going to the intake regardless?

Click to expand...

You want full volume into the pump, and just throttle the output down. The pump HAS to run in liquid, or it will fry.

If your MLT output is too small, you might have to look at building a "Lauter Grant", which is a container with a float switch that sits between the MLT and the pump. When the Grant fills enough, the float switch activates the pump. When the level drops too low to keep the pump full, the float drops and switches off the pump, until the volume trickles back up.

Cpt_Kirks said:

You want full volume into the pump, and just throttle the output down. The pump HAS to run in liquid, or it will fry.

If your MLT output is too small, you might have to look at building a "Lauter Grant", which is a container with a float switch that sits between the MLT and the pump. When the Grant fills enough, the float switch activates the pump. When the level drops too low to keep the pump full, the float drops and switches off the pump, until the volume trickles back up.

Click to expand...

Right. That's why I gravity drain my MLT, because the output would be too slow. Or batch sparge, with it wide open.

If you are trying to fly sparge on a single tier, you would need two pumps.

Ball valves should be in place on all inputs and outputs of your vessels. The HLT valve would be open all the way to flow into the pump. The input to your sparge arm would be restricted to match the flow out of the MLT.

The output of the MLT would be open all the way into the second pump. The input to the BK would be restricted to obtain the flow rate you want.

A grant would not be needed. Adjust the flow into the kettle to hit however many minutes per gallon you feel works best for your system. The flow into the MLT is adjusted to try to maintain 1-2" of water above the grain bed.

Once the flow is established, minor adjustments may have to be made to account for a small bit of grain clogging a valve, but it should be pretty much hands off.

This is using a perforated false bottom in a Gott cooler.

I batch sparge, but still reduce the output from the MLT connected pump to about a third full stream. Even though I recirculated it, that gives the sparge a little extra time for good rinsing, and makes sure I don't overrun the pump.

Jacks up my efficiency, too.

I gravity feed sparge water to the MT and pump directly from the MT drain valve to the BK. I use gate valves on both the HLT and the output side of the pump. IMO, the gate valves provide much more precise flow control than the ball valves. I've never found it necessary to use a grant. Been doing it this way for years with no problems at all.

Thanks everyone. I appreciate the insights.