Pump size for hermes system

[philelmes]

Hey guys. Ive had a quick look on the forum but couldnt find anything relevant. Im looking at building a hermes system but just wondered what size pumps people are using. I currently have 3 x 50ltr kegs which im going to adapt for the system. plan on making 9gallon(uk) batches.
Also, for the resurculation pump on the mash tun, do i need to install a filter/quaze on the exit?

Any advise would be appreciated

 

[BrunDog]

Standard March or Chugger. Some use DC food grade pumps or solar water pumps.

-BD

 

[rudylyon57]

Hey guys. Ive had a quick look on the forum but couldnt find anything relevant. Im looking at building a hermes system but just wondered what size pumps people are using. I currently have 3 x 50ltr kegs which im going to adapt for the system. plan on making 9gallon(uk) batches.
Also, for the resurculation pump on the mash tun, do i need to install a filter/quaze on the exit?

Any advise would be appreciated

Chugger or March pumps are normally restricted at their outlet during mash recirculation to prevent hydraulic compacting and clogging of the grain bed. The smaller Chugger, common in home-brew size setups, is rated for 7 gpm at low head. That high flow is great when transferring wort, cleaning pipes & hoses or just moving liquids around. However, I estimate that while mashing you only need 10-20% of that flowrate and too much flow will cause the problems mentioned. Setting the grain bed slowly will give you the filter needed.

 

[BrunDog]

rudy: not sure what point you are making, but most of the home brewing community uses these pumps with ball valves on the outlet, and there are very few, if any, problems with this setup. It is how the manufacturers design them even - they are magnetically coupled and handle deadheading and clogging very well.

I can also attest that nearly any flow range can be achieved with this arrangement, as I have used flowmeters to measure flow.

-BD

 

[rudylyon57]

rudy: not sure what point you are making, but most of the home brewing community uses these pumps with ball valves on the outlet, and there are very few, if any, problems with this setup. It is how the manufacturers design them even - they are magnetically coupled and handle deadheading and clogging very well.

I can also attest that nearly any flow range can be achieved with this arrangement, as I have used flowmeters to measure flow.

-BD

Hey BD- Just illustrating a min and max flow range based on use and what brewer wants to do. Minimum flow is recirculating during mash and max while transferring (except sparge). So, if OP is just interested in mash circulation maybe 2 gpm pump will suffice, otherwise a larger pump with an outlet restriction (ball valve) might suit. Might give the OP a broader choice.

Not sure if "any flow range" is true as I have clogged and even bent a false bottom with excessive mash circulation flows. I qualify that with that is with RIMS. I assume HERMS also passes circulation flow across a grain bed?

 

[BrunDog]

Oh, I see. You make a good point that the OP was asking about recirc for mashing only. I read it as what people normally use. My bad for jumpin' on ya!

-BD

 

[MusicalBrewer]

Sorry for digging up an older thread....

I am in the process of designing an electric HERMS build and I have a question similar to OP (which doesn't appear to be answered).

When recirculating for the mash, does pump size (in gallons per minute) matter?

Asked another way...is it better to have a 7 gpm pump throttled 50% (random number only for example) over a 14 gpm pump throttled 25%? I've read a little about pumps getting warm when they are throttled down for an extended period of time.

 

[jeffmeh]

Size based upon your maximum desired flow rates. Magnetic drive pumps can be throttled down on the output side without problems.