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"I was thinking of using only the two middle tubes on my PSII HC column condenser (leaving the top and bottom tubes open). The two middle tubes are adjacent and at 90 degrees to each other so they seem like a logical choice. Has anyone experimented with this? If so, what did you observe?
When I do my spirit runs I always use low wines (30% - 40% abv) and low volume (12 L - 16 L) and I insulate my boiler. This lets me use a lot less power once things are up to temp. One of the covenient side effects is this places the power setting on the RSC in the vicinity of mid-scale (not to be confused with half power) so it's easy to trim the power ... it's not very sensitive to small changes. However, the flow of water through the column condenser is a mere trickle. Just a slight twitch of the valve can make a big difference (in terms of heat exchange). The valve is nowhere near ""mid-scale."" It's barely opened so it's just too sensitive. Based on the way I run my rig, using all four tubes seems to be a bit like using a backhoe where a garden spade would do.
Anyway, I was planning on giving this a try the next time I do a reflux run and wanted to know if anyone has tried this.
Regards,
--JB"
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Rank: Senior Member Groups: Registered, Moderator
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"souns like you are feeding the tower either separately or before you feed the liebig. perhaps just feeding the liebig first and then the tower would allow you to have better control because the cooling water would be a bit warmer. also feed the tower water through the bottom tube first---
(((( just a perhaps)))"
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Rank: Senior Member Groups: Registered
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"Scotty, As usual, yoiu are correct. I split the flow: one to the leibig, the other to the column condenser. I only use a single valve as that's all that is needed. I dropped a nice ball valve in there which performs much better than the stock plastic one. I also feed bottom to top ... but that's doesn't make much of a difference. There are really only three things I can do: (1) increase the temperature of the cooling water (which just isn't practical or even very manageable); (2) reduce the water flow (which is the problem in the first place); (3) decrease the heat exchange surface area. NOTE: please keep in mind my performance in thermo class  ... but #3 seems the only practical option ... I don't see any other way. I actually want to increase the water flow so I can get better ""fine tuning"" control, so I have to reduce the efficiency. I have plenty of water as I have a 45 gallon container. I've never had any issues keeping the water cool enough. Now, as the run continues the water will warm up since I'm recirculating -- that will bring the efficiency down -- that's good. But most of the fine tuning is early in the run. I can get close to what I want as it is now, but I really don't like those tiny little movements of the valve. If using only two tubes doesn't cut it, I may have to find myself a suitable needle valve or something. --JB"
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Rank: Senior Member Groups: Registered, Moderator
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"i really dont understand the problem because i havent modified my cooling system yet-- i alwys used tap water which is a constant 65 degrees f.-- i could always get the slow drip feeding the water through the leinig and into the tubes from the bottom. i would test for luke warm output from time to time. I time allows, we can convert a refrigerator into an air or water cooling system
i question wheather we are nuts/fanatics or what-- i took thermo 2 times--it was my weakest subjet"
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Rank: Senior Member Groups: Registered
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It's not really a problem ... maybe more of an annoyance. I use so little water through the column condenser that a tiny movement of the valve can change the collection rate from say 1 - 2 drops per second to a string of beads. Trying to get to say 3 - 4 drops per second is a real PITA. Regardless, I'd say we're nuts/fanatics and what!  I'd love to take thermo again ... now that I have the motivation, I just might do well in that class!
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Hey JB why are you going to use the middle tubes? If I were going to use limited cooling I would have thought useing the top tubes would have been the ones to use.
I like your idea as I find adjusting the flow a PITA even with a brass valve instead of the plastic one. Let us know how it works out.
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Rank: Senior Member Groups: Registered
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On my rig the middle tubes are the only two adjacent tubes that are at right angles to each other ... so I figured that would cover the area best. I always stuff some copper mesh around the tubes ... I'll continue to do so.
I have a brass ball valve as well ... it's MUCH better than the plastic one. But based on your comment, I guessing that you have just a small trickle running through your column condenser as well.
Unfortunately, I won't get to test this for a while. I'm in the middle of a rice whiskey project so I'll be doing pot runs until I get that wrapped up ... provided it doesn't end up as a complete disaster.
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Rank: Senior Member Groups: Registered, Moderator
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it seems to me that you just need to reduce the efficiency John, why not eliminate the elaborate dual input cooling system and go bact to the old standard. We all may have created the problem by trying too hard to improve on the old cooling method of water in through the bottom of the liebig and then from there into the lowest of rhe 4 tubes and then through all 4.
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Rank: Senior Member Groups: Registered
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Originally Posted by: John Barleycorn  Scotty, As usual, yoiu are correct. I split the flow: one to the leibig, the other to the column condenser. I only use a single valve as that's all that is needed. I dropped a nice ball valve in there which performs much better than the stock plastic one. I also feed bottom to top ... but that's doesn't make much of a difference. There are really only three things I can do: (1) increase the temperature of the cooling water (which just isn't practical or even very manageable); (2) reduce the water flow (which is the problem in the first place); (3) decrease the heat exchange surface area. NOTE: please keep in mind my performance in thermo class ... but #3 seems the only practical option ... I don't see any other way. I actually want to increase the water flow so I can get better "fine tuning" control, so I have to reduce the efficiency. I have plenty of water as I have a 45 gallon container. I've never had any issues keeping the water cool enough. Now, as the run continues the water will warm up since I'm recirculating -- that will bring the efficiency down -- that's good. But most of the fine tuning is early in the run. I can get close to what I want as it is now, but I really don't like those tiny little movements of the valve. If using only two tubes doesn't cut it, I may have to find myself a suitable needle valve or something. --JB Hi JB, I use the almost the same cooling set up that you do. My liebig is flow in at the bottom and out the top, my column is in at the top and out the bottom. This keeps the coolest water the farthest from the heat source. Liebig flow is set to full thru the entire run. The column flow is set to trickle thru the entire run. On my one good run the only times I adjusted (increased) the column flow were to induce reflux and then back down to trickle. On the few times I got a stream I adjusted the rsc down until I got back to 2-3 drips per second. Towards the end of my run the rsc is at the low end of low. I think the solutiom may be a lower wattage rsc controlled element. I may go from a 2000w to a 1500 watt next. Kind of like the way the turkey fryer setups just use a small almost non existant flame setting. I'm still very much a newbie so I could have it all wrong but I'm staying with the heat management system for now. Maddawgs
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" Quote:I think the solutiom may be a lower wattage rsc controlled element. This gets confusing ... so I'll clarify a bit. It is precisely because I use such low power that I need so very little cooling water to my column condenser. There's so little water trickling through the condenser that even tiny changes in water flow result in big changes in collection rate. I know you're one of the folks who understand how I run my rig so I'm confident you know what I'm talking about. After warm up, I bring my power way down ... just enough to collect a few drops/second. For me, going from two to six drops each second is a big change. What I'd like to be able to do is to swing that valve open/close a few more degrees without seeing such big changes, so the plan is to try using less surface area in the condenser to see if that makes my adjustments easier ... an experiment. I'm trying to find out if anyone has already tried that. Or to see if anyone wants to give it a try and tell us what they observe. I will definitely try this the next time I do a reflux run. My current project will be strictly pot stilling, so I doubt I'll get around to this for a while. Regards, --JB"
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Rank: Senior Member Groups: Registered
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Originally Posted by: John Barleycorn This gets confusing ... so I'll clarify a bit. It is precisely because I use such low power that I need so very little cooling water to my column condenser. There's so little water trickling through the condenser that even tiny changes in water flow result in big changes in collection rate. I know you're one of the folks who understand how I run my rig so I'm confident you know what I'm talking about. After warm up, I bring my power way down ... just enough to collect a few drops/second. For me, going from two to six drops each second is a big change. What I'd like to be able to do is to swing that valve open/close a few more degrees without seeing such big changes, so the plan is to try using less surface area in the condenser to see if that makes my adjustments easier ... an experiment.
I'm trying to find out if anyone has already tried that. Or to see if anyone wants to give it a try and tell us what they observe.
I will definitely try this the next time I do a reflux run. My current project will be strictly pot stilling, so I doubt I'll get around to this for a while.
Regards,
--JB Hi JB, I know what you mean about the trickle. I made almost no adjustment because I really couldn't. Even a degree of valve movement cauesed a big change. Mayby on my next run after my column temp monitiring experiment I'll try a variation on the cross flow tube set up by taking one or 2 out of the loop to see what happens. Maddawgs
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 Rank: Newbie Groups: Registered
Joined: 12/29/2012(UTC)
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" Originally Posted by: John Barleycorn This gets confusing ... so I'll clarify a bit. It is precisely because I use such low power that I need so very little cooling water to my column condenser. There's so little water trickling through the condenser that even tiny changes in water flow result in big changes in collection rate. I know you're one of the folks who understand how I run my rig so I'm confident you know what I'm talking about. After warm up, I bring my power way down ... just enough to collect a few drops/second. For me, going from two to six drops each second is a big change. [COLOR=""#FF0000""]What I'd like to be able to do is to swing that valve open/close a few more degrees without seeing such big changes[/COLOR], so the plan is to try using less surface area in the condenser to see if that makes my adjustments easier ... an experiment.
I'm trying to find out if anyone has already tried that. Or to see if anyone wants to give it a try and tell us what they observe.
I will definitely try this the next time I do a reflux run. My current project will be strictly pot stilling, so I doubt I'll get around to this for a while.
Regards,
--JB Hi JB I am new to this hobby, but I set my rig up with brass ball valves, as an upgrade from the plastic valve. After a few hours of just making steam & playing with controlling it in the column & condenser, I changed both Valves to cheep 3/8"" gate Valves, super easy for me to control now. Vapor 1"
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Rank: Senior Member Groups: Registered, Moderator
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the gate valve desigh allows for finer tuning- i still dont understand why you are having soo much trouble-- i continue to get the feeling that your cooling system is yards too efficient???? i theeeenk
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Rank: Senior Member Groups: Registered
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Vapor, thanks for the heads up about the gate valves. I'll have to see if I can find one a the local hardware store.
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