New VM Build...Can't get product out. Help?

[WithOrWithoutU2]

I have built a 3" copper column with tri clamps. I have a 36", 24" and 12" sections of column. I also have a sight glass. This will give me the ability to use various heights/configuration. I also created 3"x2"x3" Tee. I have a 2" 90 degree elbow into a 2" shotgun (24" length) to condense in Pot Still mode. I also built a CSST coil condenser for reflux. I have a 1" gate valve that I connect off the 2" part of the tee with a 2" to 1" reducer. I connect the gate valve to the shotgun condenser via 1" to 2" reducer into my 2" elbow/shotgun condenser.

All that said, I cannot get product to go through the valve and condense when using the CSST in reflux mode.

I've been just doing cleaning runs. I first did a cleaning run with 36" of height with the top of the Tee capped but did use the gate valve just to see how it would do fully open. Product came through great with no issues. Given the 3" column to 2" Tee into a 1" gate valve, the reflux ratio I read should be 10:1. I had a 23% ABV charge in the boiler and the product was coming off initially at about 90% ABV. The temp just off the tee started at 178F and when I stopped it was around 208F. While I have a 6500W element, I wanted to run it for awhile to get a good cleaning so I only ran it at about 1500W after getting to temp. It ran fast and great.

After cooling it off, I then recharged the boiler, uncapped the TEE and connected the CSST Reflux Condenser to give these parts a good cleaning. I also added a sight glass to watch the reflux. I did not add any packing as I wanted to ensure the vapor had every opportunity to clean the column. At first, I had the valve 1/3 open. I could not get any vapor to cross the gate. I could also not get the temp off the Tee to get higher than 161. So I decided to open the valve completely and increased power to 6500W. The temp off the Tee would not get over 165F and the vapor would not cross the gate valve. I was puzzled.

So I decided to remove the valve and just connect the Tee directly to the 2" elbow/shotgun. In essence, I was running it as a CCVM mode. The temp off the tee did increase to 168 but still no product making it's way across and out the shotgun. I figured the reflux distillate coming back down was causing the issue with the vapor crossed out through the Tee. So I decided to raise the coil back up the column as far as I could without letting vapor escape. The temp off the Tee did climb to 171F and very slow drips started to come out. But that was it and far from the rate that I was expecting by moving up to a 3" column with 6500W. So am baffled. I am hoping it is a simple thing that someone can point out to me.

I do wonder if the distance off the Tee to the gate is an issue. It is 5" from the edge of the Tee to the front end of the gate value. But again, I did try removing the gate and just run as a CCVM. In my mind, the issue has to be something to do with the Reflux from the CSST, because when I ran in pot still mode by capping the Tee vapor crossed through the gate valve with no issue.

(Sorry for the wall of text. I just wanted to provide as much info as I could).

Thanks in advance.

[still_stirrin]

Does your CSST reflux condenser coil block the branch line on the Tee? Does it partially cover it?
How fast is the water flow through the CSST? Is the water discharge from the CSST cold, warm, or hot?

To me, it sounds like the CSST reflux condenser is so effective at knockdown that no product can sneak by. Try slowing the water flow. Also, you can try to raise the coil, effectively opening the “valve”.

A photo of your system would help.
ss

[WithOrWithoutU2]

SS,
I had coil less than an inch above the tee branch.

After I removed the gate valve and ran as CCVM, I did raise the coil as high as I could before vapor escaped through the top. That is when I started to get drips but very slow drips. I did try turning the water flow down, but I did not test the temp of the water coming out. But I am certain it was not hot like it is when I run my boka.

I will be retesting tomorrow. I will pay more attention to the temp coming out of the RC. I will also try to take pics.

Anyone else have suggestion on what else I could check/try? I think I am going to start by just testing in CCVM first to eliminate any variables from the gate. (Anyone think the 3" column to 2" tee to 1" gate value is the issue. I have read many others doing it this way successfully).

[kimbodious]

Carefully feel on the outside of your column where the boundary between hot and cold is. That zone should be above the offtake. It is the zone where the majority of vapour has condensed.

[silverbean]

A picture is worth a thousand words.
I'm thinking running a reflux condenser without packing will cause unexpected results. Your results are unexpected.

[Tummydoc]

Is the sight glass just below the Tee and do you see reflux? How long is your CSST reflux column and how long is the spool above the Tee? I'd still suspect your RC is in the path of the Tee, but should be easy to confirm by removing the elbow to the PC and looking at the Tee.

[OtisT]

Sounds possibly like an issue with RC placement. Is your RC coil extending below the 2” takeoff point? When using your rig as a Valved VM the entire RC coil should be above the 2” takeoff point of that tee. How much column do you have above the tee?

A pic would be helpful. Otis

[WithOrWithoutU2]

[/img]

[/img]Here is a pic of the pieces and how they go together. I included rulers so you can see dimensions.

I can report I really paid attention to the temp of the return water from the RC. I made sure I kept the water flow a low as possible. I am basically keeping it on the brink of vapor escaping. The return water is HOT. While I was about 2" above the branch, I have also backed the condenser back a little more. This all has helped. My temp right off the branch was 180. The most I could collect was 118ml in 5 minutes. That is just at 1416ml an hour max. If I had it all tuned in for quality collection I would be happy with that. But that is with no packing, a wide open valve and throwing 6500w at it. When I power down to 3500W, which is what I've read is a good cruising speed for a 3" column while using VM Reflux, the collection slows.

I am getting ready to pack the column now. My SPP I used in my 2" is too small for 3"column so I am going to use bio ceramic rings (for aquariums). I'll report how that does.

If anyone sees something from the pics, let me know.

Thanks

PS. Don't judge my solder skills. They are bad. I use way to much and half of it isn't where it should be. I'll clean it up later.

[RC Al]

Your valve is much smaller than the column, so it's setting a high automatic reflux ratio.

If the top condenser was in the same diameter tube as the valve, that would set it to 1:1, the best possible with a vm, currently the 3 inch to 1 inch is a 9:1 by area. So your 118ml in 5 mins meant that just over a litre went back down as reflux in the same time

Loose the valve, shorten the top bit to drop the condenser below the level of the tee and turn it into a ccvm or cm if fixed in place, the 3:2 that tee will have a 2.5:1 ratio which isn't ideal, but more usable than you have now.

I have seen it written that a large open area below that bend (ie back up to 3" for a fair distance) will mitigate that issue somewhat, but I havent seen anyone a/b test that to refute it