Cfc And Pumps

[bonk]

ok,

quick question time. i've finally got around to use my new ag setup and was pretty happy with the how everything worked.

i've built myself a cfc and it seems to be doing a good job, however its gravity fed at the moment and has a small height for the drop from kettle to the cfc.

i'm thinking about using the pump to get it through faster, however:

which side of the chiller do i put the pump????

do i put the pump before the chiller and 'push' the wort

or

do i put it after the chiller and 'suck' the wort through??

thanks,

 

[Batz]

Before

Batz

 

[pint of lager]

Wort flow rate through your cfc will have a huge effect as to how well the system chills down. Faster is not better, unless you have a very long cfc.

If the wort is gravity feeding with your setup, you may find it will be more effective to let gravity do the work rather than pumping..

 

[Doc]

I have a 1/2" ball valve on my kettle and only have it half open to gravity feed through my convoluted counter flow chiller, which is serviced with a pre-chiller (my old immersion chiller in an esky of ice).
Any more than half open and the temp of the wort exiting the CFWC his over 25 degC.
I have an inline aearator after the CFWC with a temp gauge on it so I can tune the wort out speed and water in speed through the CFWC to get the cooling right.

Beers,
Doc

 

[dicko]

Hi Bonk,
You dont mention what type of pump you are using but you also need to consider sanitation of the pump.
If you are using a March pump then it is important that it goes BEFORE the chiller so that you can restrict the outlet and control the flow.
Any pump you use would be easier to sanitise if fitted before the CFWC as you can run boiling water through it and the CFWC from the HLT to sanitise this part of your system at the end of the boil.
I cant comment if it is some other brand of pump as you may not be able to adjust the flow by restricting the outlet and it may not handle the high temps for sanitation with boiling water.
I think it was Batz who said
" you are not a brewer if you dont have a March Pump" :lol: :lol: h34r:
Cheers

 

[JasonY]

I think it was Batz who said
" you are not a brewer if you dont have a March Pump" :lol: :lol: h34r:

I think Batz should make that his signature

 

[Batz]

I think Batz should make that his signature

:lol: can get in enough trouble already without adding a signature like that :lol:

Batz

 

[bonk]

Dicko,

nah i'm only a 'wanna be' and use one of the pond type pumps :lol:. so i'll need to mod it if i want to restrict the flow.

i might try it again (no pump) and try varying the flow of the hot wort (using water) and tap water flow rate to see what gives the best results.

thanks,

 

[user 384]

Bonk

I drain my kettle through a CFC using only gravity, and like many others I don't open the ball valve completely in order to get a good balance between the flow of hot wort and cooling water. So I would say that as long as there is a big enough drop to start a syphon, you will be OK. In this situation a pump is primarily useful for moving the hot wort when the outlet of the kettle is at the same level or below the fermenter and a syphon can't be used.

On my own set up, the inlet for the CFC is at the exact same height as the outlet of the kettle, so there is no drop here. However I have a long piece of tubing that extends all the way from the CFC to the bottom of the fermenter. There for I have a drop that equals the height of the fermenter, plus the height of the CFC and this is plenty for a good syphon.

Cheers
MAH

 

[Andrew]

Hi Bonk,
For what it's worth, I have a 1/2" ball valve between the kettle and a pump and then to the CFWC. You contol the temp of the wort to the fermenter with the ball valve. Easy.

Cheers

 

[sosman]

FWIW I have heard multiple times that it is important to throttle march pumps on the only. I am only repeating that here - maybe someone has an authoratitive reference.

 

[dicko]

Hi Sosman.

I dont have an authorative reference for these pumps but -
The March pump is not a self priming pump and therefore has to work with a flooded inlet.
If you restrict the inlet you may find that the pump will eventually overheat and cause damage. Having said this, I believe that these pumps can run dry for a short time without a problem.
By restricting the outlet, the pump remains fully primed and hence, no damage and a slower flow.
Maybe someone has all this written in text on the pumps or a Google might reveal more info.

Cheers

 

[Justin]

I have read also that the pump MUST be throttled on the output side. Throttling on the input can cause you to run your pump dry, and cause cavitation. I think I read on the march website or instruction sheet that the maximium amount of time that you'd want to run your pump dry was about 30sec, after this your running the risk of burning the impeller onto the shaft (or at least damaging it).

JD

 

[user 384]

On the March website it clearly states:

"Flow rates should be controlled by the discharge valve only, never by the suction valve."

A full copy of installation instructions is available under the section Pump Documents CAD and PDF Files from http://www.marchpump.com/

Cheers
MAH

 

[Batz]

Perhaps it is my trade but restricting the suction side of any pump is not allowed , to me this is obvious.
Be it water, hydraulic or what ever this is a no no , even the suction line feeding the pump should by rights be of the same diameter of that of the pump , with a March pump this is 1/2" , although I am sure our ball values in a fully open state do restrict the flow too a minor amount.

Your not a true brewer till you own a March pump <_<

Batz

 

[Guest Lurker]

Maybe not authoritative, but I occasionally have to spec pumps in my day job.

Short answer, what Batz said. Pump before CFC.

Long answer
Not just a March pump, but for any similar pump like a fountain pump, it is designed to operate with unimpeded flow on the inlet, and is quite happy to push hard against the outlet (although most pumps have a minimum flow rate you shouldnt reduce below). If you impede the inlet you risk cavitation and pump damage. Cavitation is basically bubbles in the fluid going through the pump. The bubbles can come from a number of sources. If you restrict the inlet you reduce the pressure in the fluid coming in, so either gas dissolved in the fluid returns to vapour form (gaseous cavitation), or if the pressure drop is enough or the fluid is warm some of the actual fluid can vaporise (vaporous cavitation, the fluid essentially boils below the usual boiling point). Most pumps can handle a little gas going through, but once it gets to around 6% of the volume in the pump you will get cavitation, flow will be unsteady and you will hear nasty knocking noises from your pump.

Mind you March pumps are a waste of time when you have a Hydraulic Boiler Liftovator.

 

[Batz]

Mind you March pumps are a waste of time when you have a Hydraulic Boiler Liftovator.

Your not a true brewer unless you own a March pump

Or a Hydraulic Boiler Liftovator :lol:

Batz h34r:

 

[big d]

oh well looks like im not a real brewer.ive neither march pump or liftovator.

 

[Andrew]

Bonk, I'll probably get in trouble/shot down in flames with the others saying this, but if you are only using a fountain pump not a Batz errr, I mean March pump then my guess its a magnetic impellar type pump? If so, no moving parts (other than the rotating impellar) and therefore no real hassle to restrict the flow on the inlet side, like I do and recommended earlier.

This is no real hassle. Why?

There is a major upside to this:
1. If I am right in the long term you save a few quid doing it this way.
2. If I am wrong its even BETTER - eventually thing blows up and you tell the missus that the only way NOT to waste money in the long-term is to replace it with a Bats err March pump. Thus you get to be a real brewer.

Cheers!
:chug:

 

[Jazman]

Bugger it so i aint a real brewer with a bloody pond pump must get a Batz pump