--- In email@example.com
, "rye_junkie1" <rye_junkie@...> wrote:
> --- In firstname.lastname@example.org, "mavnkaf" <mavnkaf@> wrote:
> > Mason, can I ask what is the size of your VM side arm tube and gate valve? I can't remember. Also do you open your gate valve wide open? Or open a little bit until you get the rate you want?
> > I've been doing the later, opening a little bit until I like the take off rate but I'm starting to think I might be holding it back no good reason and that's why I'm getting a slower rate.
> > Next time I do another run I'll try a WOT (Wide Open Throttle), I mean valve wide open, for a bottle or two to see what happens. I should mention my VM side arm tube is 1 inch and so is my ball valve.
> > Cheers
> > Marc
> I am running a 1" Gate valve on the VM side. I do not run it wide open as the take off rate gets pretty fast and Purity drops. I did do another run yesterday and was able to pull 1L/hour at 95%. 1.25L/hour dropped it to 94% That was with the valve about 2.5-3 turns open. I had to shut it down before I went to bed and was still in the hearts. I plan on firing it back up today after work and finishing the run. I may try the "WOT" just to see what the max take off would be. Also I would be interested in what your max take off is. Reason being i use a gate valve and you use a ball valve. A gate valve allows for a direct vapor path whereas the ball valve makes the vapor go through a couple of Hoop T Doos(Technical Jargon) to get through it. That may hinder take off rates. I also put in a couple of extras in my head to create turbulence. One being the thermometer tube even with the VM tube. In my mind, this placement splits the vapor helping to push it to the VM take off and helps achieve higher rates. Weather it works or not is another story. I am also running 1440 watts.
> I took some pictures yesterday and put them in my album a little while ago. Knowing that the rig has the potential for 1.5L/hour take off It makes the 60" column even more enticing.
Thanks for that Mason, I think I can see whats happening, (just guessing though), I think I'm running my still just a tad bit slow and with a 1100 watt element, and you have about 340 watts more power going into your still than me, hence the faster take off rate.
According to Tony Ackland `s site, the more power you use in a fractionating still, (providing the column can handle it), it will create a higher reflux ratio, which will let you a have a higher take off rate, providing there is enough separation going on.
To get the liter per hour and still keep the 95% , you must collect about 16 milliliters per minute, (with your 1440 watt element) and you would have reflux ratio of 7.3.
On the hand, if I collect at 16 milliliters per minute, (with my 1100 watt element), my reflux ratio would be 5.6.
This is what Tony say's about it, also the calculator for this is just below this paragraph on the Home Distillers site.
"To get a fractionating still to work at its best also requires quite a high reflux ratio - returning 8-12 times back to the column vs that which is kept. To do this means knowing what the total rate is, then trimming the offtake valve to only take a portion of it. Do this by opening the valve fully and measuring how fast it is coming out, then closing down to only take what you should. Once you know this setting (say 1 drip per second), it will be the same for future runs."
So I think I'm a bit under powered and, or maybe taking off product too slow as well. In that calculator I used, it takes no notice of the height of the column? According to Tony's HETP calculator it tells me that I have HETP value of 20.8, that's got to help some, right?
I think I'll just keep doing what I have been doing, well, maybe a bit faster next time to see if the purity remains the same.
Ps I will run it at WOT to see what the flow rate is, to compare.