Bolverk wrote: ↑Fri Jun 23, 2023 8:01 pm
How far down are your stripping to?
Whatever they need.
My sugar washes seldom produce a foreshot, but my rums sometimes produce a foreshot and a pint before they go into the main boiler, that is why I had to give the preheater it's own Leibig.
My triple distilled whiskeys are stripped so low that well before the end of a strip there is more ethanol coming from the preheater than is being produced by the main boiler.
Even though my pot and preheater are insulated, I get more from the preheater in summer than in winter.
Thanks, I was trying to get an idea of how long it was taking for the preheater to get up to temp. It takes me 1.5h (minus heat up time) to strip 5g of 6% wash down to about 15-20%. Would the preheated 5g be ready as soon as the first charge is done?
You guys ever think about putting a dimroth or Ccvm reflux condenser on the preheater pot to keep it open, but also knock down the alcohol from coming off until you're ready to transfer it over to the pot (instead of having a second stream of distillate)? Im thinking that depending on how fast the preheating charge takes to get up to temp, it could sit and reflux for a while... kind of early Fischer Esterification chamber.
There are two types of people in this world.
1. Those that can extrapolate from incomplete information.
That is one of the drawings I found when I was designing mine. In the interests of self preservation and not wanting to make the 6 o'clock news, I didn't copy the lack of a vent.
That is the classic pic that circulates.
If you were to take it at face value , it’s a one and done going straight into a barrel . It could be argued that the tails cut was well before the charge in the pre-heater got up to temp .
But I’d agree fully with NZChris . The detail of a pressure relief of some kind is not obvious , but only a fool would not include one .
Perhaps its the pointy thing atbthe top
Yummyrum wrote: ↑Sat Jun 24, 2023 2:37 am
That is the classic pic that circulates.
If you were to take it at face value , it’s a one and done going straight into a barrel . It could be argued that the tails cut was well before the charge in the pre-heater got up to temp .
But I’d agree fully with NZChris . The detail of a pressure relief of some kind is not obvious , but only a fool would not include one .
Perhaps its the pointy thing atbthe top
What would you expect to need pressure wise if a PRV was installed?
Or are you talking old school, weighted cap or ball bearing in a tube jobby?
Yummyrum wrote: ↑Sat Jun 24, 2023 2:37 am
That is the classic pic that circulates.
If you were to take it at face value , it’s a one and done going straight into a barrel . It could be argued that the tails cut was well before the charge in the pre-heater got up to temp .
But I’d agree fully with NZChris . The detail of a pressure relief of some kind is not obvious , but only a fool would not include one .
Perhaps its the pointy thing at the top
What would you expect to need pressure wise if a PRV was installed?
Or are you talking old school, weighted cap or ball bearing in a tube jobby?
I have no idea what was the norm when that pic was drawn Moose , but if I was to do it , I’d want to either , have a reflux condenser ( open to the atmosphere) that returned any vapours alcohol back to the pre-heater ….. or …. A condenser that ( again open to the atmosphere) might take off any fore-shots that would start to present .
Thats just me . As I said , I have no idea what the pointy thing is . Maybe its nothing other than an artist impersonation of something they didn’t understand …. Or maybe they just liked to place a pointy thing at the top of a thing .
I guess my point is , it’s nothing more than a basic sketch and as NZChris mentioned , one should not take it at face value , but analyse it and fully understand what it represents before blindly following it .
The lack of a vent of some sort made me question the design.
When I first started looking at these I was really new I didn't exactly understand what I was looking at.
Maybe that pointy cap thing is loosely fitted? Maybe the charge didn't get so hot that the contents started to vaporize, I didn't know...
Here's a pic of one with a lyne arm on the preheater that intercepts the main lyne arm.
Attachments
There are two types of people in this world.
1. Those that can extrapolate from incomplete information.
Thanks Bolverk
That pretty much clarifies it . Any vapours that start to occur in the pre-heater are fed to the PC .
Now ain't that funny . So around when late hearts to tails transition is likely to be coming out the spout from the main boiler charge , in comes the foreshots from the next pre-heated batch .
You gotta wonder if thats about where they pull the pin and do a change over
Ive never had charentais but that's how I'd drive this still, monitor the temp on the preheater charge and just before it hits 150f/65c I'd bypass it so nothing contaminated my pot charge. That or not connect them at all and use a ccvm type condenser so it's open to the atmosphere but knocks down any vapor.
There are two types of people in this world.
1. Those that can extrapolate from incomplete information.
If one day I have the time to do something like this, I'll definitely be using an open port on top with a condenser coil to knock down anything it produces.
That way, unless I'm missing something, you have total control of the pre heated charge until it goes into the main still.
For avoiding stratification, would a slanted, false bottom in the pre heater work?
By this I mean the vapour from the main vessel would enter the false bottom at the high end, and be continuously pushed to the low end exit, heating the wash above it. The underside of the pre heater vessel would be well insulated to push all the heat upwards.
Instead of multiple turns/coils inside the preheater maybe the reason for the single pass through pipe is to not heat up the charge so much it start to give off vapor, but just enough to keep the warm up time for the next charge low.
For instance if I could get the preheated charge up to around 145f/62c nothing should be vaporizing yet and when its transferred over to the boiler it would only take about 15 mins to start producing vapor again.
There are two types of people in this world.
1. Those that can extrapolate from incomplete information.
Bolverk wrote: ↑Sat Jun 24, 2023 5:28 amHere's a pic of one with a lyne arm on the preheater that intercepts the main lyne arm.
Man, these chinese designs... I've even seen one like that made of Red Copper!!
On many of the traditional designs that are in service today, the preheater looks to have a sight glass/manometer. It is certainly not a system I'd endorse, as a sleepy still operator could easily be venting vapour to atmosphere if he has dozed off before opening the two-way valve to bypass the preheater.
Bolverk wrote: ↑Sat Jun 24, 2023 11:13 am
Instead of multiple turns/coils inside the preheater maybe the reason for the single pass through pipe is to not heat up the charge so much it start to give off vapor, but just enough to keep the warm up time for the next charge low.
I think this is a basic illustration and not a set of build plans. You can be overly efficient by having too many coils and you can be inefficient by having none. I doubt anyone wants to use an inefficient design on purpose. Especially if they are in it to make money.
Look at the designs, use common sense, don't ignore the relevant physics, don't copy bad designs.
If they want to produce, let them, but keep the vapors separate, as the higher proof from the preheater raises the ABV at the spout and will have you facepalming yourself the first time it happens.
If they produce, you may get the foreshot before it goes into the still. You might even get some strip.
There is no good reason for going to the trouble of refluxing it or adding a worm bypass, as letting it produce saves you time and money, which is the point of building one.
Heat rises, so the worm should enter and exit as low as possible. It is very gentle heating, so don't expect turbulence to help it heat much below the worm.
Plumb it so that you can dump and recharge quickly, without dismantling anything.
