Trouble with T500 & cold water

[bjurcina]

I'm running a T500 for the first time and having a lot of difficulty controlling temperature. We have used it before with no problems but its the first time I've used it myself. I set it up and started using it with water flow set at 450ml/min as per instructions for cooler climate. After 2 hours and nothing coming out I slowed down water flow and temperature began to climb until it started producing. Water flow was reduced to a very small trickle. I'm guessing our ambient water temperature is extremely low. <10c. What seems to be happening now is that in order to get column temperature up to 78c I have to let the outlet temp rise to 65c and higher. I get good flow then but I'm worried about quality. On the other hand if I bring outlet temperature down to 60c then the column temperature starts to fall and that seems to cause outlet temp to drop even lower and then it just keeps falling. This is all within just a hair of movement on the control valve. I've resorted to wrapping the column in tinfoil to keep the heat in and I've soaked the water feed in a tub of warm water from the outlet pipe to help heat up the inlet water. My theory is that when water flow is too slow through the tower it doesn't cool properly and when inlet temp is too cold it over cools and can't be adjusted properly. Any thoughts? Or am I just out in left field on this?

[i dont drink]

noop that sounds about right. the outside water is about 7ºc here and in the summer it can be as high as 17! so you need less cold water to cool the t500.

the needle valve is a known cow to use and not the best of control devises and almost everyone moans about the lack of control but thats how they are. they tell you to look for the 450ml as a guide but i never use that due to the water being so cold just now and all i do is adjust for the temp and not the water flow.

as long as your temp is between 55 and 65ºc, you should be ok.

hth
al.

[Admiral Toad]

Totally agree with al mate needle alve is v sensitive

Personally I stuck a 21/2 Inch nail on the top to turn it into a 'lever valve' and this makes it easier to control small movements

[Capt-Cudellez]

bjurcina, a few things to consider.

1. could there be air in the cooling system, I found that could cause problems, on warm up, blast the water to purge the air, before turning back to a trickle.

2. the thermometer might be gubbed, the ones that come with the T500 are cheap and cheerful, this is not an issue as long as they are repeatable. I would measure the output rate of the spirit - when its 600-800ml (please someone jump in if I'm off with that take off rate - its been 10 months since I ran my T500 and I'm too lazy to go out to the garage to get my notebook)
When the take off rate is right, see what the temp is and aim for that for the next run.

3. how old are the battery's in the thermometer? they can start reading off when low.

[bjurcina]

Thanks guys.

Admiral Toad - I was thinking the same thing. A lever valve would make it easier to judge movement in the valve.

Capt-Cudellez - Next time I will purge the lines and verify the thermometer readings with a digital meter.

The strange thing was that no matter what I set the flow rate at the temperature in the gauges would constantly swing from a low reading to a high reading and then back. Each time it did that it would discharge a bit of alcohol. It never had a steady flow rate. It's like the vapour would build up in the tower and then suddenly condense and drain off, pulling heat out with it. I was in the garage doing it which was cold as well and next time it will be doing it in the furnace room.

If the temperature is below 55 then I'm guessing it will just not produce any flow and above 65 you will have lots of flow but too much of it will be actual wash liquid and not pure alcohol.

[Admiral Toad]

Could be your local environment sometimes I get wierd fluctuations that can only be to do with the folks around me maybe running baths etc. When you see how tiny the movments of the needle valve alter outlet temp its little wonder ! Hopefully you're not next to a Chinese laundry or car wash

[i dont drink]

i actually dont turn the tap on full!.. i turn it on just enough and then alter the flow with the needle valve and iv found that to help with fluctuations.

al.

[YHB]

I do not have a T500 and this is an untried solution but a solution that I believe would help.

Pressure reducing valves are used to control outlet pressure and take care of fluctuations.

I believe that installing a valve such as the one shown on the link below would;

a) Smooth the flow and reduce the effect of other users on the water system.

b) reduce the pressure to the cooling supply and therefore make it more controllable.

http://www.mathewsonandrosemond.co.uk/d0434a-34-honeywell-pressure-reducing-valve-p-2770.html.

Anyone experience of these?

[Admiral Toad]

Yes very good idea just ordered one with pressure gauge off EBay for £18.50 all excited now !

[Jimmy]

Yes very good idea just ordered one with pressure gauge off EBay for £18.50 all excited now !

Let us know how you get on with it, I could do with one but I'll let you test it before I splash out! (pardon the pun)

[Admiral Toad]

Wow got pressure relief valve today having paid extra £2 for first class excellent service looks spot on.company I used through E bay were called Team Supplies.
And sparkleloid here as well ! Happy days !

[Admiral Toad]

Should get valve fitted in time for next run in a day or two so will report back .(Inc sparkaloid performance) fingers crossed !

[Admiral Toad]

Well managed to fit a T off the kitchen sink water supply pipe with an isolater valve then the pressure controller more copper pipe then soldered to the T500 needle valve from which the clear pipe flows to the still so you can simply pop the clear pipe into the cupboard when not in use
First tests look good set it at 1and a half bar, set needle valve to trickle at about stilling rate and it took EXACTLY the same time to fill a jar even if sink tap just 18 inches further downstream or the loo was flushed while it was running. Most encouraging hurry up washes !

[Jimmy]

Sounds great! Sorry for being thick, but are you saying that it doesn't fit to the standard plumbing fittings, i.e. if you already have a T500 which connects to a water supply under the sink, you need to buy some more pieces to be able to use this as well?

[Admiral Toad]

Hi Jimmy no the needle valve fitting supplied fitted the end of my mixer tap but like many was getting pressure fluctuation and temperature instability
So have put a branch off the sink feed to put the pressure regulator on then needle valve then pipe to still, the idea being it does not restrict the pressure to the sink tap which can now be used when doing a run = happier missus