Thread: Off topic need to build a Recirculating water system for my still ideas and opinions?

I have just brought a still cheap to add to my home brew gear
If you are un aware stills need a Constant water flow to keep the condenser cool while running
For arround 4-5 hours you are running arround 60leters per hour of water
Im on tank water so this is an issue also at this relatively slow rate the pump will keep turning off and on makeing for inconsistent water flow Makeing for fluctuating condenser temperature also an issue

So what I need to make is a recirculateing system with a pump that pumps water into the still and the outlet pipe drains back into the reservoir for the water to be pumped back into the still again
The water coming out of the still is warm so will warm up the water so I will use large blocks of ice in the reservoir to keep
the water cool

I also need to be able to control the amount of water being pumped into the still to adjust the condenser temperature
This is normally done with a small tap on the inlet hose and I geuss i can stick with that to adjust the amount of water flow
into the still

Any ideas ? Pump types what to use as a reservoir (im thinking a old chilly bin)
Cheers

I have some experience with the process having worked in the industry for a while, I would say that 4-5 hours does seem a long time to run a pot still unless your heating is quite poor. If you like pm me.

Originally Posted by berg243

split output line of your pump with a ball valve on each with one running directly back into reservoir the other into still adjust flow by closing off each valve to get required amount.i would think a 200 litre plastic drum with a small bilge pump or aquarium pump would be the go.if you need cooling for your outflow a 60 litre drum with your out let pipe running through it in a couple of coils in the drum filled with iced water or a heat exchanger pipe with water from your house supply running back to your house tank so not losing water.you can make a heat exchange unit out of pvc pipe and fittings but drum would be cheaper but you will need ice.

Interesting you say 200lts why do you think it needs to be so big?
I was thinking 60 would be plenty myself
That’s one full reCirculation per hour
With 2 or 3 ice cream container size blocks of ice floating arround in there should keep it cool enough?
I like the idea of haveing it running back to the water tank but sounds complicated and I don’t have room to permanently set anything up
ether so will have to stick with a Reservoir idea

flow through the condenser should have the distillate coming out at the same temp as the water is going in. Over 5 hours to get 2 litres of absolute alcohol from a reflux still you will have boiled off and condensed near 10 litres in total.
Starting with 60 l of water at 15deg it will be nearly 30 when you finish far too warm to be efficent,so bergs 200l for a closed system is a pretty good estimate. But his idea of running hoses to and from your house tank is pure genius, you wouldnt even need ice as the thermal mass of water in the tank
wouldnt even notice.

Originally Posted by berg243

recirculating water back to tank is a couple garden hoses kept solely for this ends sealed when not in use.if you go with reservoir more water in reserve better heat reduction in holding tank plus you can use a bigger pump if more economic to purchase.slower you recirc total water better heat dissipation ,also depends on water temp leaving still as a high temp will melt your ice quickly and lift temp in your reservoir.you could also wrap a pipe around the pipe exiting still and pump water through it back to your house tank using house pump as a pre cooler to keep temp lower in your reservoir.

That makes sense mate

Water coming out will be arround 60c give or take so it will warm things up quite quick
At 1 ltr per minute give or take
So I can understand how a bigger tank would work better

Want to stay away from useing the house pump as much as possible as at that rate the pump will turn on and off every few seconds creating pressure fluctuations and wear and tear

Would a solar garden fountain pump be any good

Maybe the still will be inside though so solar may struggle
They are pretty cheep on trademe mate
Range from $10–40 for something that will do the job
The issue is all the small ones are 12volt not really an issue but 240v is just one less thing

Most have rectifiers to take 240 down to 12 volt so that should be no problem. Is 60 deg out important? The stillhead temp determines yield and purity

Yeah a 12volt pump would be easy as to sort out so not worried about that
And yes you are correct the temperature of the water exiting the still has nothing to do with the function as long as the condenser temperature is correct as you know
But in this case the out water will go into the Reservoir and will warm up the water in the Reservoir and eventually increase the temperature of the still head easy to sort with ice
But im trying to work out how big tank needs to be so the water has time to cool before being pumped back into the still

Originally Posted by rambo-6mmrem

Yeah a 12volt pump would be easy as to sort out so not worried about that
And yes you are correct the temperature of the water exiting the still has nothing to do with the function as long as the condenser temperature is correct as you know
But in this case the out water will go into the Reservoir and will warm up the water in the Reservoir and eventually increase the temperature of the still head easy to sort with ice
But im trying to work out how big tank needs to be so the water has time to cool before being pumped back into the still

Assuming your water comes on at 15C and if you are 60C outlet temp there is 3.14kW heat to remove.
Latent heat of freezing for ice is 334kJ/kg.
That’s around 35kg of ice over an hour. To get your surface area up your going to want to add ice in smaller amounts over time.
Servo bag of ice is 3kg and $5 a pop. So you need 12 bags of ice or spend $60.
Fill a tank. Drain to waste. Forget the ice. Forget the pump. Do it simple.

Go back to bergs excellent idea of running hoses from your house tank and use the fishtank pump to circulate it. 32000 l isnt going to notice a few kw

Consider really old cars did not use to have a water pump for their coolant systems. Worked by natural convection currents, warmer water rising, etc. Just need sufficiently thick hoses to minimise flow resistance.

Drew the hooch red to warn of its potential effects on liver, family life, blood pressure, etc. Enjoy.

Your drawing represent some water into a beer handle glass: heretic! :-)

Originally Posted by Friwi

Your drawing represent some water into a beer handle glass: heretic! :-)

@Friwi

Hahaha! How come I did not step back and see that!?! (-:

Serious, about the drawing - I was asking myself afterwards, why not make it even simpler by running the coiled tube through the top and bottom sides of the main tank.

Successfully run a wash through the still today
Just run a small pump out of a 100ltr drum through a Needle value to control flow rate to the still
The intention was to top the drum up from the hose when it got low
I wasn’t worried about wasting water this time i just wanted a simple set up less to go worng
Turns out though that the still only used 200-300ml per minute and the hole run only used maybe 50 more like 30-40 ltrs
So not worth my time with a complicated set up
So that’s awesome