2 inch Boka to CCVM. DAD300 was right.
Posted: Thu Jun 03, 2021 1:28 pm
Well, after about five years, I finally bit the bullet and re-did my 2" Boka still into a CCVM. It was originally built as a modular still, which made the conversion easy. I re-used my 3/8 copper reflux condenser and used a bunch of new stainless parts and tri-clamps bought off of eBay. I built the product condenser from parts purchased there as well. It's 3/4 over 1/2 copper and only had one leak when I pressured it up. It was a small water leak on the outside, so instead of dismantling the entire thing and re-doing the joints, I just brazed over the offending joint with sil-fos brazing wire usually used in HVAC work. The column is 48" of SPP (bought on eBay from that guy in Poland) over a 13 gallon milk can boiler powered by a 5500 watt water heater element.
I just did my cleaning run. Some observations:
1. This thing is fast. I have easily doubled my product make over the Boka. I have a stream now instead of a fast drip.
2. The vapor temperature seems locked in. It stayed at the same temperature until very late in the run. I know exactly how much 96% I put in the boiler (three liters) and I didn't see any increase until I was well into the last liter. The vapor temperature reacted immediately to any change in the condenser height. There's a K thermocouple in the vapor takeoff elbow, routed through an Omaga temp indicator to an old laptop that allows me to set alarms, graph the results, etc. Some folks have varying ideas about vapor temperature monitoring, but I have 34 years of commercial petroleum distillation experience, so it's information that I'm used to working with.
3. The reflux condenser let a small amount come out the product line - even with the condenser stuck in as much as I could - I've since cut 2" off of the top spool, which will allow me to push my condenser lower into the tee piece. Hopefully. we'll get it all next time. It was only a drip, but I'd like to condense everything at the start of a run.
4. The new Liebig product condenser does knock down all of the vapor, but the output temperature runs about 92F instead of the 65F that I used to get from the very low flow through my Boka's old product cooler (1/2 over 1/4). I'm going to have to use a table to adjust my hydrometer readings because they're calibrated for 60F.
5. As I approached the end of the run, the flow dropped way off and then the vapor temperature began to increase. This is going to be much easier to operate than the Boka, which didn't give me such obvious feedback.
All in all, I'm going to have to learn how to operate this new setup, but as of now, it seems a lot less finicky and much easier to operate than my old LM still. We'll see how I feel about it after a few more runs, but right now, I'm excited.
I'll be starting a new UJSSM batch up tomorrow after I run out for some sugar.
Thanks to DAD300's excellent posts and explanations. It made it easy.
I just did my cleaning run. Some observations:
1. This thing is fast. I have easily doubled my product make over the Boka. I have a stream now instead of a fast drip.
2. The vapor temperature seems locked in. It stayed at the same temperature until very late in the run. I know exactly how much 96% I put in the boiler (three liters) and I didn't see any increase until I was well into the last liter. The vapor temperature reacted immediately to any change in the condenser height. There's a K thermocouple in the vapor takeoff elbow, routed through an Omaga temp indicator to an old laptop that allows me to set alarms, graph the results, etc. Some folks have varying ideas about vapor temperature monitoring, but I have 34 years of commercial petroleum distillation experience, so it's information that I'm used to working with.
3. The reflux condenser let a small amount come out the product line - even with the condenser stuck in as much as I could - I've since cut 2" off of the top spool, which will allow me to push my condenser lower into the tee piece. Hopefully. we'll get it all next time. It was only a drip, but I'd like to condense everything at the start of a run.
4. The new Liebig product condenser does knock down all of the vapor, but the output temperature runs about 92F instead of the 65F that I used to get from the very low flow through my Boka's old product cooler (1/2 over 1/4). I'm going to have to use a table to adjust my hydrometer readings because they're calibrated for 60F.
5. As I approached the end of the run, the flow dropped way off and then the vapor temperature began to increase. This is going to be much easier to operate than the Boka, which didn't give me such obvious feedback.
All in all, I'm going to have to learn how to operate this new setup, but as of now, it seems a lot less finicky and much easier to operate than my old LM still. We'll see how I feel about it after a few more runs, but right now, I'm excited.
I'll be starting a new UJSSM batch up tomorrow after I run out for some sugar.
Thanks to DAD300's excellent posts and explanations. It made it easy.