SS reflux - cooling pipes mod.

[MrCat]

Just picked up a bit of new 8mm tube, two 'y' joints http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=390192885949and a mini ball valve http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=390162027975 for less than a fiver.
This will allow me finer control on the water to the reflux cooling jacket and the water for the jacket will come straight from the tap so it will be cooler than the water it normally gets that's already been heated by the condenser. It also means that I can run in pot still mode without removing/changing any of the water lines.
Didn't have to cut any of the existing lines so I can put the head back to stock when I get my T500.
Took all of 5 minutes (I could have done it in less but I decided to do a proper job)
It looks like this


newlines by Mister_Cat, on Flickr

[Opus 27]

Notice you have insulated your boiler. I gave this some thought but then realised I was hoping for a bit of reflux off of the top end of my boiler so decided against it. What advantage have you gained with this?
Opus 27

[MrCat]

That\'s actually it left in the box!! I did run it with some radiator insulation around it the body of the boiler and didn\'t really notice an appreciable difference. I guess now the colder weather is here I might notice more of a difference with draughts etc
You get one HETP plate for the boiler, then a further one for the mesh in the column then multiple plates for the packing in the column, then of course more plates for the reflux jacket etc etc.
If you are getting 93%+ then in effect you have 7 or 8 HETP plates anyway.
I think we\'ve got these down to pretty much as good as we are likely to get them - I had an idea to pack the column totally with copper mesh disks which should in theory give me the maximum possible number of plates and surface area but I then asked \"why should I bother\" - why isn\'t 93% good enough? which was pretty much when I set about making it easier to run.

[marc83]

Have been meaning to do this to my cooling lines also,did you get a noticeable improvement on the finished product?or was it more of an easier control thing?either way i guess its good.

I wrap my boiler with 1/4inch thick foam,and hold it in place with a pin,was a suggestion made when i was having issues with unstable temps,i started doing this the same time as i modified my cooling inlet,made a huge difference to the temps,so dont know which one was to thank,haha.
I will be picking up a couple of y-fittings this weekend,have 2x25L washes to run through the still.

[MrCat]

One thing not shown is the that you need two valves as I found out the first time I ran it. You need a second valve on the output from the condenser to create back pressure or all the water goes that way instead of splitting and going through the reflux jacket.
There was little difference in the finished product, it\'s just easier to control the temperature as the ball valve gives more accurate control than the tap. You can just wind the tap on and allow a trickle through to the reflux jacket.
I split the cooling output lines and put a thermometer in the output from the reflux jacket as it seemed to indicate a rise in temp before the temp gauge at the top of the column did.
I\'d say it was a mod that made life easier rather than improving the output.
I only ran three washes this way before I went computer controlled though.

[Phantom]

One thing not shown is the that you need two valves as I found out the first time I ran it. You need a second valve on the output from the condenser to create back pressure or all the water goes that way instead of splitting and going through the reflux jacket.
There was little difference in the finished product, it\'s just easier to control the temperature as the ball valve gives more accurate control than the tap. You can just wind the tap on and allow a trickle through to the reflux jacket.
I split the cooling output lines and put a thermometer in the output from the reflux jacket as it seemed to indicate a rise in temp before the temp gauge at the top of the column did.
I\'d say it was a mod that made life easier rather than improving the output.
I only ran three washes this way before I went computer controlled though.

When I\'ve got 5 minutes over the weekend, I\'m gonna order the Y pieces and valves. Not sure that I follow the bit about splitting the output lines or how I could put a thermometer inline for the output of the reflux jacket though....
As for computer controlling ? Nah! that\'s a step too far for me. I\'ve been stuck in idiot mode with a truck strapped to my arse too long......
Where did the nice reinforced tubing come from ? As "he\'s" only got the normal clear stuff down the local HBS......

[MrCat]

I got the 8mm hose from the same seller on ebay
http://cgi.ebay.co.uk/8mm-Clear-Braided-PVC-Airline-Hose-Koi-Pond-5-Metre-/280465219234?pt=UK_HomeGarden_Garden_PondsWaterFeatures_UK&hash=item414d079ea2
It\'s just used for the cooling water so it doesn\'t have to be food grade.
By splitting the output I mean\'t instead of joining the hoses back up and having one hose running to the drain I kept the two hoses seperate and had two going to the drain.
To monitor the reflux output water temperature I just stuck the probe from a kitchen digital temperature sensor in the drain end of the tube so it told me how hot (or not) the water was - I was just watching for a change in temperature.
My temp sensor is kind of like this

Does that make sense ?

[Phantom]

Yes, it does. My digitherm is rather more basic than that, plus I probably couldn\'t get an accurate record of the temp changes as I have to run quite a long piece of hose to the drain - so I suspect that any accuracy would be lost - plus I\'d have to get another thermometer as at the moment, it\'s got PTFE wound round the probe and sits in the reflux chamber thermometer bung......

[MrCat]

watching the output water temp isn\'t important so I wouldn\'t worry about it

[Phantom]

watching the output water temp isn\'t important so I wouldn\'t worry about it

Ok, I\'ll just order the requisite parts and see how I get on......
TVM MrCat
regards
P.

[Phantom]

Ok, so here's what mine looks like at the moment picture here, as I can't, for the bleeding life of me, work out how to show it within the bloody text.....
Now the input to the reflux jacket is split from the input to the condenser, then outputs from both are joined again (unless they should have separate outputs direct to drain ). The valve in the picture is on the output of the condenser as I wanted to create the back pressure mentioned MrCat above.
I haven't put a tap on the input to the reflux jacket yet, as I want to see how it all works with the reflux mods.
The power controller is inline as well. The only thing I can't do as yet, is to monitor the wattage at the plug, as they're out of stock at Maplins and I've ordered one but they're on back order.
I'll probably get some of the stainless scrubbers from Tescos later this week, so I can compare the amount of mesh from 3 or 4 scrubbers to how much copper mesh I've put in the reflux head (hell if need be, I'll just cut copper mesh the same length as the unrolled scrubbers. I don't get how you might get copper separators into the reflux head as surely the hole is too small
I've just fired it up at the moment so it's heating up now. I'll just have to have a bit of a play with the power controller i.e. it's on "full" (as far as I can tell - turned all the way to the right) at the moment, once it's up to temperature, I'll turn it down to about the "half" setting (only guide being the shaft position as I haven't bought a knob for it, and the power/wattage meter as above).
As for the current amount of packing, well I had 1 longish piece and 2 short pieces in the reflux chamber last time, but just one long and one short at the moment, just pushed down so the top is in line with the position of the reflux jacket.
I'll post again when I know how it's performing....
p.s. Oh and as you can see from the pic, my thermometer is rather more basic than the one that MrCat was explaining about earlier.....

[Phantom]

Bugger! It\'s sitting nicely at 78.4 degrees C but theres next to nothing coming out the still at the moment. So I presume that the mesh is giving the reflux chamber to higher a reflux ratio ?
So I\'ll give it a half hour, and if still nothing shows, i\'ll remove the mesh and change it to just the longer piece less firmly pressed in.

[Phantom]

Ok, so now I\'m completely stumped......
I\'ve had to remove the shorter of the two pieces of copper mesh, then put the longest piece back in, packing it in to approximately the level of the reflux collar.
Which has sort of worked i.e. it\'s improved the reflux ratio so that the still is running. The pipe mod and power controller (I think, mainly the power controller) seem to have given me a finer control so I\'ll be happy when the power meter eventually turns up from Maplins.
Now where I\'m stumped, is that while this is a \"spirit\" run, so the still contains about 20 litres at about 40% ABV, the output is still only measuring up at about 82/83% ABV, so I\'m not entirely sure what it is, that others are doing and achieving 92/93% ABV - maybe I should put the shortest piece of copper mesh back in (so the reflux chamber has the shortest and longest pieces in it).
Or do others have more mesh in the reflux chamber so that the output to the condenser is actually coming from within the mesh ?
Or possibly that the 3 (or was it 4) unravelled scrubbers is \"accidentally\" the right amount of mesh to use to get a perfect reflux ratio and the mythical number of \"plates\" ?
So, what am I doing wrong I wonder

[Opus 27]

Hi Phantom,

I use three scrubbers and I don\'t bother unravelling them. I just stuffed them in with the handle of a wooden spoon untill the top surface was about 18-20mm below the feed tube to the condenser. I let the temperature hover around the mid to high 70s for about 45 mins with little or no output this I assume is the reflux sorting out it\'s stacking as eventually it gets to settle out around the 78-79 degrees and starts producing. I start saving when it stays consistently above 79 and below 82. Before and after these temps is either heads or tails which I throw. My wash averages 14.8 ABV. Just started a run this morning and had a slight drop in ABV to 92% not sure why. But as long as I can stay around the 90% mark I\'m happy.
Opus 27

[Phantom]

Ok Opus, I\'ll have to go to tescos and get a pack of the scrubbers as well, then I can work out roughly how much I need to shove in the reflux chamber. It maybe that I\'ve never used enough and/or waited long enough for it to equalise, but then again, I\'ve also had it where it still comes out at about 85% or so but takes all bleedin\' day i.e. 12 hours or so just to get 4 litres of spirit.
We\'ve just got back from lunch, and there\'s about 4 litres now (which isn\'t surprising as the still charge was about 40% ABV anyway i.e. a distillation run). I just measured the stuff in the receiver and it\'s about 80%, so I\'m guessing that it might be that I\'ve gone from one extreme to another....
I might switch it off and put the small piece in then see what it measures up at......
regards
a still confused P......