Adventures in Closed Loop

Finally got set up last night to test the vacuum connectors and the two glass flasks together. Works great. I've been wondering if I need vacuum grease on the ground glass connectors.

Nope. It pulls down to nothing in a hurry, no leaks.


Do you know how much you lose? Do you weigh your butane tank or how do you tell when you lost some?

I'm just getting set up to run the first time.
Yes, I always weigh my tank so I know when it'empty, how much I get in return, and then when it's all topped off and full.
I get an average of 75% return.
My tank holds a case of tane and I only need 3-4 cans to top it off again.
 
For the record. Sight glasses have their uses, but their limitations as well. The Chinese manufacturers say they will withstand 150 psi, but not in any of their official brochures. Accepting that at face value, the ANSI rating would be around a third of that, or 50 psi.

While a system will normally operate under 50 psi, it is possible to hit over 100 psi with heat and the right combined screw ups, and a system should tolerate worst case scenario.

A butane storage tank is limited to an 80% to keep thermal expansion pressures under the 350/450 psi limits on the tanks, so consider if you have your sight glasses on the columns between two closed valves, and the column is full to the brim, that you have hydralic pressures greater than 150 psi. I know of two instances of someone loosing track of what they were doing and exploding their top of column sight glass.

All of WolfWurx, Inc commercial units use high pressure sight glasses in all applications, rated from 720 psi at 250F, and available to 3000 psi.
Yeah, these rigs can be dangerous. ALWAYS pay attention!
My rig runs at 40psi... 50-60psi max.
My storage tank full is 80 psi... 100 max when pressurised to blast..
 

Doer

Well-Known Member
Hmmm.......So, you are not running a passive system, obi? I intend to run in cold vacuum. I expect to get a lot more than 75% recovery.

Am I wrong about that, do you think? I don't think there can be much pressure at all in a passive setup.
 

Doer

Well-Known Member
IAC, just to document the steps. Liquid n-butane has a density of .573 grams per milliliter

- load material in 3 x 6 inch column
- put all the gear with material, in the freezer over night
- place LP5 tank in 100 degree water
- vacuum gear to 200 microns with 3/8" line (I can pull even lower, but don't want to risk it)
- place 2 liter butane jug in salt ice bath to keep it below 30 degrees
- hook 1/4 inch line between tank and jug
- put cold jug on scale
- open valves and put in 900 grams (1600 ml) of liquid n-butane through tank's liquid siphon.

So, where is the pressure? There isn't any. Jug might be at atmospheric pressure from it's vapor. The receiver and material are cold in vacuum.

- hook 1/4" line between jug and receiver
- open valves
- pour in butane
- close valves

And I missing something about this?
 
Hmmm.......So, you are not running a passive system, obi? I intend to run in cold vacuum. I expect to get a lot more than 75% recovery.

Am I wrong about that, do you think? I don't think there can be much pressure at all in a passive setup.
I can get more return but I'm going for a good clean pour out of my catch chamber. I've gotten a 85+% return but the concentrate comes out really gooey and makes it much harder to scrape all out.

My rig runs at @40psi. Very low pressure..
 

Fadedawg

Well-Known Member
IAC, just to document the steps. Liquid n-butane has a density of .573 grams per milliliter

- load material in 3 x 6 inch column
- put all the gear with material, in the freezer over night
- place LP5 tank in 100 degree water
- vacuum gear to 200 microns with 3/8" line (I can pull even lower, but don't want to risk it)
- place 2 liter butane jug in salt ice bath to keep it below 30 degrees
- hook 1/4 inch line between tank and jug
- put cold jug on scale
- open valves and put in 900 grams (1600 ml) of liquid n-butane through tank's liquid siphon.

So, where is the pressure? There isn't any. Jug might be at atmospheric pressure from it's vapor. The receiver and material are cold in vacuum.

- hook 1/4" line between jug and receiver
- open valves
- pour in butane
- close valves

And I missing something about this?
Here is a n-Butane pressure/temperature chart. At 100F (310.928K), n-Butane is at about 50.76psi (3.5 Bar).

Looks like at 20F (266.483K), vapor pressure is about half a bar or around 7.25 psia.
 

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Doer

Well-Known Member
The pressure is in the butane...?...
Does your rig have a pressure gauge?
I let temperature push the tane through the system and recover.
Yes, I have pressure gauge ports available and a couple of gauges.. I am just setting up for the first run now.

I just wanted to understand your pressure comments first. ;)

Just waiting for the scales to get here. So, I'm doing cleaning and final set up now.
 

Doer

Well-Known Member
I just finished the first trial run, tonight and I think I need more practice. Well, I know I need a lot more Ice.

What didn't go so well?
- the transfer hose is too long
- the hose swivel fittings are difficult to get a good seal
- I really didn't know a good way to see if I was finished and all the Butane was back
- I lost some Butane, in various ways

What did go well?
- freezing all the parts and material over night
- the gram scale worked fine
- 15 min of soak time seemed productive
- the initial transfer of Butane from tank to Jug was easy
- only lost 300 grams of Butane (out of 900)
- jug holds pressure at room temp, no loss, so far
- a dream to work with Sanitary fittings, easy clean
- I recovered 2 more grams after winterizing from 3 ounces of tailing already tube run once

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Doer

Well-Known Member
It is totally green. I was not running any good stuff or even shake. This, Primo bud, already had 6 cans of Butane thru a tube. So just tailings for testing with. I used a coffee grinder to fine grind it.

So, I'm surprised it yielded anything. But, after winterized, filtered and fan evaporated I set the glass plate in the sun for 2 hours, until it was nicely golden.

The UV destroys the chlorophyll. I got 2 grams I didn't know I had, bro! I forget to take pictures of that.

Oh, btw, I found a very good glass plate.

It is my microwave platter turned upside down. Completely flat but with a 1/4" high saucer edge. That would be the turned down edge when the glass plate is right side up and twirling food around for even cooking..
 
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