Which side the March pump?

[jjbuck]

Have upgraded to a Therminator.On which side should I put the pump?; Wort in or on the wort out side (cooled wort). I have planned on using 1/2" tubing going in and 3/8 going out (mostly because the in line thermometer is 3/8" ). I don't need the pump to get the wort to the chiller, gravity should do that nicely but I need the pump to send the chilled wort to the primary. I was guessing that hot wort thru the pump was a better idea than cooled to help keep down contamination, but I've never worked with a plate chiller before. Am I going to have problems with bubbles and clogging with the pump upstream of the chiller?

[JimF]

I use my pump on the cool side mostly because that is where it fit best. I don’t worry about contamination so much because when cleaning up, I use the pump to recirculate cleaner solution through my therminator and hoses and finally starsan solution through them.


From: jjbuck [mailto:brew-equipment@crbeernuts.org]
Sent: Saturday, February 02, 2013 5:30 PM
To: brew-equipment@crbeernuts.org
Subject: Which side the March pump?



Have upgraded to a Therminator.On which side should I put the pump?; Wort in or on the wort out side (cooled wort). I have planned on using 1/2" tubing going in and 3/8" going out (mostly because the in line thermometer is 3/. I don't need the pump to get the wort to the chiller, gravity should do that nicely but I need the pump to send the chilled wort to the primary. I was guessing that hot wort thru the pump was a better idea than cooled to help keep down contamination, but I've never worked with a plate chiller before. Am I going to have problems with bubbles and clogging with the pump upstream of the chiller?




Brother John Brewing
The Monk at the Marion Monastary

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[Steven P]

I'm going to be doing the same thing later this spring. My intent is to have the pump between the boil kettle outlet and the plate chiller.

I plan on recirculating back to the boil kettle until I hit pitching temp, then after everything settles I'll move to the fermenter.

[JimF]

If you are using a therminator you won't need to recirculate, one pass and you'll be down to pitching temp.
On Feb 2, 2013 6:48 PM, "Steven P" <brew-equipment@crbeernuts.org (brew-equipment@crbeernuts.org)> wrote:

I'm going to be doing the same thing later this spring. My intent is to have the pump between the boil kettle outlet and the plate chiller.

I plan on recirculating back to the boil kettle until I hit pitching temp, then after everything settles I'll move to the fermenter.



"Payday came and with it beer"
- Rudyard Kipling

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[Steven P]

So would you then suggest doing the whirlpool hot?

[DrPaulsen]

I put my pump on the hot side of the chiller to minimize restrictions between the boil kettle and the pump.  I want as much force as possible on the pumping path to minimize the opportunity for clogs.  I've seen my pump grind up and pass things that seem like they would have just created a clog in the chiller.  Plus, it's relatively easy to disassemble a pump in the middle of a brew session and remove a clog, in the rare event that it does happen.  It's unpleasant, but at least it's possible.


On Sun, Feb 3, 2013 at 8:24 AM, Steven P <brew-equipment@crbeernuts.org (brew-equipment@crbeernuts.org)> wrote:

So would you then suggest doing the whirlpool hot?



"Payday came and with it beer"
- Rudyard Kipling

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[-MG-]

I put my pump on the hot side of the chiller to minimize restrictions between the boil kettle and the pump.  I want as much force as possible on the pumping path to minimize the opportunity for clogs.  I've seen my pump grind up and pass things that seem like they would have just created a clog in the chiller.  Plus, it's relatively easy to disassemble a pump in the middle of a brew session and remove a clog, in the rare event that it does happen.  It's unpleasant, but at least it's possible.

I do the same thing.

[Matt F]

I second that. Pump pushes much better than it pulls. The plate chillers go to a small interior diameter. It is best to push through a restricted area than pull. That said, it works either way as people are doing both.

You can go boil kettle, to chiller, back to boil kettle to do a whirlpool at the same time you chill. That is how the infamous Brutus 10 does it. Then you are whirlpooling and cooling the entire volume similar to what I do with my whirlpool immersion chiller. Then when you have chilled the wort, turn the pump off and let the kettle sit for 20 minutes or more. That allows the whirlpool to do its thing and your wort is already chilled. Then pump very clean wort to the fermentor.

[tony b]

For once a mechanical engineering question (vice the normal electrical ones on this site!).

Pump pushes much better than it pulls. The plate chillers go to a small interior diameter. It is best to push through a restricted area than pull.

That would be your Net Positive Suction Head (NPSH) requirement on the pump. If the pump can't adequately draw in fluid faster than its discharging it out, it will cavitate, which leads to major pump internal damage or motor burn up. So, like Matt said, make sure that the hose going into the pump suction is always bigger or the same size as the line going out the discharge side.

It will also cavitate if the fluid is near its boiling point in temperature, because as the fluid pressure drops inside the pump, the fluid will flash to gas phase (steam if it's water) and bind up the pump, because steam is a compressible fluid and the pump can't push it out. It just ends up compressing it, which the pump motor doesn't like either. It also creates vortexing issues at the end of the pump vanes and erodes them, shortening the life of your pump.

Last good rule of NPSH is to have the suction tank elevation higher than the pump inlet to build up static pressure head. If you want to move fluid from a lower to higher elevation, it takes a special kind of pump (lift pumps), or pump motors with lots of torque. Even with a high torque motor, you still run the risk of cavitation by drawing a vacuum on the suction side and burning up the pump motor.

Tricky stuff, that's why it takes Engineers to design this stuff. Blickmann is a Mechanical Engineer!