Stripping on the shoulders of giants
Posted: Tue Feb 20, 2024 2:19 pm
Stripping stills have been interesting to me for some time. I did my first experiments with them 2 summers ago, and have been reading and scheming since then.
Over the last couple of days I have been putting together my first attempts at a serious stripping still, and learned a bit, which I'd like to share here. I don't have good photos at the moment as I was running it outside in the evening after work, with low light.
I'd ordered some modular parts from OakStills for most of this. At the moment, I am just testing the capabilities of everything, and am not consuming anything from this still.
The basic idea is somewhat like the continuous still that the Russian Dr. Gradus shows in his youtube videos. If you look at Yummy's thread - there is a lot in common, except that there is a dephlegmator above the wash infeed. I thought about whether this was necessary - as we are not looking for high abvs, and so sending vapors back down the column was not really necessary.
In the end, I decided it didn't make too much difference, since incoming wash would do the same job of sending vapors back, and decided to put the defleg in. This was my first mock-up of how the still would go together. It's based on a 4" column, and I have about 3800w to drive it. I took this a couple of evenings ago.
Rather than having a boiler, the element sits directly at the bottom of the column. This design is seen on the stilldragon forum a few times I think.
There's about 75cm of packed section, and I have packed the column with expanded clay balls as they are abundant and cheap. I have a couple more 12" (30cm) long 4" sections and I could add these to the column if I feel I need more height.
I was using a Kamoer speed controllable peristaltic pump to feed the column. I bought this from Aliexpress, it does up to 1.6L/Minute apparently. Unfortunately, the display on the pump never worked. I am in contact with them to get a replacement/refund, but it means I can't really measure/track the rate I feed wash into the column
.
First attempts at running this configuration:
Yesterday, I was running an all grain wash, (Barley, Wheat and a bit of oat), and it was foaming like a M********. I could drive the column with about 70v, I think that the element is about 16ohm resistance, so that's about 300w. If I did more than that, the foam would just overwhelm the column. I just gave up, after having no luck.
Today, I picked up some anti-foam, and added it to my barrel of wash (about 150L), and stirred (by hand). This helped a lot.
I added a 12" unpacked section of 6" spool underneath the packed section of the column. The idea being that any foam up would not rise up as much or as readily in this wider, unpacked section.
I had to play around a lot with the airlock/u-bend section where the wash exits. If there was too much power, for some reason, fluid was surging out of this.
The modifications I made were to make it deeper - therefore adding more fluid to it, and having a heat exchanger on each side of the 'U'. I recall the improvements that YummyRum saw in his setup with adding more heat exchange to the fluid outlet.
Whilst we're on the topic of heat exchangers - the route of the wash is currently -
Product condensor ->Ubend closest to column,->Ubend furthest from column (exit side) -> defleg in column above feed point ->column.
My thinking here is that the vapour temp should be less than the overflow temp - vapor having higher abv, and overflow hopefully having very little alcohol, so be close to boiling point of water.
When running the column - vapor temp was about 95c, - indicating 45%abv I think. Tomorrow, I will try running the wash first through the column outflow, and next through the product condensor. I have an additional condensor running from mains water, so it is not essential to use wash to knock-down vapors.
To overcome the surging exit from the overflow- I added a section of 4" tee, so that there was a lot of fluid in there. Aside from foaming, this surging out through the ubend was a major headache and one of the challenges to overcome in getting this to run properly.
This was the setup that I got working. Here is the detail of the bottom section - with the 6" spool,
and here is the U-Bend (again, really sorry about the **** photos - I will take some better ones tomorrow in the light!). To run the column - i used the following technique -
1) Pump wash into the column until it flows out of the overflow - and then stop pumping.
2) Switch on heat. Heat up slowly, so that foam doesn't rise up the column.
3) Use the vapor to heat everything in the column. This needed patience. I kept switching on the wash too early, and it never worked. In the end, I realised that I needed close to boiling point in ever spot for heat exchange, to help heat the incoming wash.
4). When vapor is exiting the column, switch on water to the auxilary condensor (without wash in it). Let the wash in the product condensor heat up.
5). when I was happy that everything in the column was hot, i slowly switched on the wash feed. Very slow.
6). Slowly increase the power in the column. - I had been to cautious about this. In the end the column ran better the more power I pumped into it. It seemed that the antifoam was working now, or the 6" spool section - and I could run the column with more power. Additionally, I think that the falling product and recondensed vapors helped to manage foam up; whereas during heat up, it seemed that all vapors, liquid, and everything was only moving 'up' the column, and the foam went that way.
7)slowly increase the feed rate. In the end, I was getting about 1L of output every 14 minutes - so about 4.3L of low wines per hour. I was running very cautiously and am pretty sure that I could up this a bit. I did play around with wash feed speed a bit, and got a bit of foaming at the feed point if I increased it too much, so backed it off again.
When the column was running - it was actually pretty stable, and just kind of ticked along.
Overall - really pleased to have got it running.
Need to do some more testing, and get some better photos (maybe video!) of it all working in daylight.
Over the last couple of days I have been putting together my first attempts at a serious stripping still, and learned a bit, which I'd like to share here. I don't have good photos at the moment as I was running it outside in the evening after work, with low light.
I'd ordered some modular parts from OakStills for most of this. At the moment, I am just testing the capabilities of everything, and am not consuming anything from this still.
The basic idea is somewhat like the continuous still that the Russian Dr. Gradus shows in his youtube videos. If you look at Yummy's thread - there is a lot in common, except that there is a dephlegmator above the wash infeed. I thought about whether this was necessary - as we are not looking for high abvs, and so sending vapors back down the column was not really necessary.
In the end, I decided it didn't make too much difference, since incoming wash would do the same job of sending vapors back, and decided to put the defleg in. This was my first mock-up of how the still would go together. It's based on a 4" column, and I have about 3800w to drive it. I took this a couple of evenings ago.
Rather than having a boiler, the element sits directly at the bottom of the column. This design is seen on the stilldragon forum a few times I think.
There's about 75cm of packed section, and I have packed the column with expanded clay balls as they are abundant and cheap. I have a couple more 12" (30cm) long 4" sections and I could add these to the column if I feel I need more height.
I was using a Kamoer speed controllable peristaltic pump to feed the column. I bought this from Aliexpress, it does up to 1.6L/Minute apparently. Unfortunately, the display on the pump never worked. I am in contact with them to get a replacement/refund, but it means I can't really measure/track the rate I feed wash into the column
.First attempts at running this configuration:
Yesterday, I was running an all grain wash, (Barley, Wheat and a bit of oat), and it was foaming like a M********. I could drive the column with about 70v, I think that the element is about 16ohm resistance, so that's about 300w. If I did more than that, the foam would just overwhelm the column. I just gave up, after having no luck.
Today, I picked up some anti-foam, and added it to my barrel of wash (about 150L), and stirred (by hand). This helped a lot.
I added a 12" unpacked section of 6" spool underneath the packed section of the column. The idea being that any foam up would not rise up as much or as readily in this wider, unpacked section.
I had to play around a lot with the airlock/u-bend section where the wash exits. If there was too much power, for some reason, fluid was surging out of this.
The modifications I made were to make it deeper - therefore adding more fluid to it, and having a heat exchanger on each side of the 'U'. I recall the improvements that YummyRum saw in his setup with adding more heat exchange to the fluid outlet.
Whilst we're on the topic of heat exchangers - the route of the wash is currently -
Product condensor ->Ubend closest to column,->Ubend furthest from column (exit side) -> defleg in column above feed point ->column.
My thinking here is that the vapour temp should be less than the overflow temp - vapor having higher abv, and overflow hopefully having very little alcohol, so be close to boiling point of water.
When running the column - vapor temp was about 95c, - indicating 45%abv I think. Tomorrow, I will try running the wash first through the column outflow, and next through the product condensor. I have an additional condensor running from mains water, so it is not essential to use wash to knock-down vapors.
To overcome the surging exit from the overflow- I added a section of 4" tee, so that there was a lot of fluid in there. Aside from foaming, this surging out through the ubend was a major headache and one of the challenges to overcome in getting this to run properly.
This was the setup that I got working. Here is the detail of the bottom section - with the 6" spool,
and here is the U-Bend (again, really sorry about the **** photos - I will take some better ones tomorrow in the light!). To run the column - i used the following technique -
1) Pump wash into the column until it flows out of the overflow - and then stop pumping.
2) Switch on heat. Heat up slowly, so that foam doesn't rise up the column.
3) Use the vapor to heat everything in the column. This needed patience. I kept switching on the wash too early, and it never worked. In the end, I realised that I needed close to boiling point in ever spot for heat exchange, to help heat the incoming wash.
4). When vapor is exiting the column, switch on water to the auxilary condensor (without wash in it). Let the wash in the product condensor heat up.
5). when I was happy that everything in the column was hot, i slowly switched on the wash feed. Very slow.
6). Slowly increase the power in the column. - I had been to cautious about this. In the end the column ran better the more power I pumped into it. It seemed that the antifoam was working now, or the 6" spool section - and I could run the column with more power. Additionally, I think that the falling product and recondensed vapors helped to manage foam up; whereas during heat up, it seemed that all vapors, liquid, and everything was only moving 'up' the column, and the foam went that way.
7)slowly increase the feed rate. In the end, I was getting about 1L of output every 14 minutes - so about 4.3L of low wines per hour. I was running very cautiously and am pretty sure that I could up this a bit. I did play around with wash feed speed a bit, and got a bit of foaming at the feed point if I increased it too much, so backed it off again.
When the column was running - it was actually pretty stable, and just kind of ticked along.
Overall - really pleased to have got it running.
Need to do some more testing, and get some better photos (maybe video!) of it all working in daylight.