Nah, it was a Boka reflux column. I had the takeoff valve closed so that it could reach equilibrium, which is why the pressure started building. It also probably started building because I had the condenser water just barely trickling and the burner on high. Thinking back, it was definitely a series of dumb mistakes I made while learning to run the still properly. But I figure on top of eliminating ignition sources in the unlikely event of a leak, a hot water bath would also prevent scorching the extract.
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Helps even more if youāre using vac.
Or so is the tell 
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Even heating with steam there is a fine line between āfinishedā and ānot coming outā. With direct it would be pretty easy to over cook those very valuable cannabinoids
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Was it the BVV disk? I was looking at it the other day while cleaning and I can definitely see that happening. Iām wondering if they used some kind of epoxy to glue it in. And I have done hot scrubs in the past in both ethanol and heptane but didnāt notice any significant difference over a room temp scrub. Iām a bit worried about doing a dry scrub with hemp oil for fear of isomerization, but it might be worth experimenting with a small batch.
Yep it sure was bvv those cock suckers it broke quick. I was think not room temp but like 60-90c. Whatās you opinion on keeping my etho solution around 5:1 and then scrub or do I bring to oil then scrub and bring back to 5:1 for filter or use the the heptane and scrub with that?
Yea, my plate is kinda loose but Iām still not getting any fines through yet. Thanks for the heads up though, Iāll have to get a welded one as a backup for when it finally does fail. Iād give dry scrubbing a shot then adding the ethanol or heptane just to filter. I didnāt get any better results scrubbing in solution than I ever got by simply running it through a filter cake. Though I will say, I got much better results filtering through a stack of media with heptane rather than filtering with ethanol. The crude remained about the same color with both solvents, but the distillate quality was WAY better after the heptane filtration.
Why was the heptane so much better? Do you extract with just plain heptane?
No, I extract with ethanol. I think the heptane was better because itās non-polar, leaving the more polar contaminants on the filtration media. I used a stack of B80, magsil, silica, AC and activated alumina. From bottom to top in that order. What confuses me is how the crude looked about the same as the ethanol filtered crude, but the distillate results were so dramatically different.
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Whatās your definition of crude ? I do a qwet and my ācrudeā is my dist a full spec oil. No short path just distilling the etho off my product. If thatās the route Iām taking would it make a difference in using the heptane or not?
I broadly define ācrudeā as anything not distilled. Though I realize thatās a pretty big range from warm 2-day iso soak to super refined and filtered cold solvent extract. For some reason though Iāve never been able to get my hemp crude as pristine as I got MJ crude, but I think the age and storage of the hemp Iāve been processing has had a lot to do with that.
That still is trash, you will fight it non stop I know this because I own one.
if you really want one like that Iāll give it to you for free.
Otherwise I can help you design a still using triclamp parts that will blow that thing outta the water
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I had my boka head go up in flames too.
Those things are dangerous, I honestly hate how it can just boil over the top like that- terrible design, efficient sure but dangerous.
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I can order just about any size condenserā¦ what do you mean?
If I wanted to build a vac still out of a keg Iām wondering what size condenser Iād need for it to make it run efficiently
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How cold can you get your condenser is a big part of that question
-20 auto chiller 5 ton ac hack plus a 2.5 ac hack or a keg full of dry ice and iso -76
Budget: run a copper coil through a bucket of dry ice and iso
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I wonder what the condenser surface area of a 50L rotovap is? That would be a good place to start for sizing a condenser. Though you can really never go too big, so Iād probably just go as big as I could afford so I can use it on a larger still later. Now that weāre talking about it, Iām wondering if I should just use the 5k I was going to put toward a 20L roto and just build my own Bain-Marie vacuum pot still. Iāll have to do some digging, but Iāve seen quite a few folks getting at least as fast of recovery as a roto if not faster with custom rigs. The hardest part seems to be agitation/stirring.
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I did a good bit of research and talked to a couple still producers (Mile High & ADE) before building my still. both of their vacuum still designs are basically the same, they use large jacketed reactors and short path style column with a 45-60* bend right at the top of the pot.
their stills are designed to be run in batch mode, they have a small water heater and a pump recirculating the water through the jacket portion.
The condenser size is related to the surface area of the evaporating liquid, vacuum level, heat input, and condenser temperature.
On the condenser I went overkill to a small degree in hopes of preventing the need for a cold trap and I got lucky. I use a dip tube in the collection vessel, the tubes in the condenser are packed with stainless steel wool. I run the condenser @ 0F without a cold trap, I have tested with a cold trap before my pump and had maybe a shot glass worth of ethanol over an eight hour recovery cycle.
There are definitely some things I would change on the evaporation side if I built my still a second time.
I built my still to run in a batch style, to me this is a lot of wasted energy, if I were to do it over I would have it run continuously. heating a smaller jacketed chamber, a 12" jacketed spool with one of @Rowan wiper setups & ferro fluid rotary feedthrough plumbed through the bottom endcap would be a good starting design. The feed could be introduced through the top endcap via small stainless tube with small orifice holes angled to spray a fine stream on the walls of the spool.
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