BHOgart Extractor Thread

[OG_TGR]

Sorry, I should have been more specific. I wasn't picturing a literal overhead hood but rather an overall extraction intake as well as an articulating leg of a venturi driven (explosion proof) evacuation system.
So essentially it's a 10' tall, walk-in, grounded laminar flow hood, with an articulating, separately powered, venturi intake to directly vent line blow off into.
Overall ventilation is provided by a 2200cfm, 12" Mixed flow fan, mounted before the main venturi, and drawing from the outside, far from any exhaust point.
Second exhaust is powered by a 1000cfm mixed flow fan, also with a separate intake and venturi configuration.


Besides this, I'm reading here and there about propane as a pre-charge? Can anyone elaborate on this concept?

..things became very interesting once i switched to the research grade tane ...

View Image


..i charged the system with .2# of research grade propane ..did a second run and still no high side pressure during recovery ..@0Hg the recovery tank had 1.5# back in ..@-16Hg the entire 3.5#'s is back in the tank ..and a bit more gas was left in the lines ..i'm guessing that was the propane...

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[Gray Wolf]

Got my BHOgart #1, G5 Appion and #30 N-Butane tank on the way!

One question I have that I haven't seen directly addressed is the restrictions to process indoors. I understand the precaution defaults here but I wonder if it would be possible to process indoors if you are in a very large volume.
For example, would it be feasible to maintain a safe environment if you were in an area of approximately 10kft^3 with an active air exchange rate of about 12xhr?

It is possible to extract indoors with a closed loop system, if it is a commercial building set up for the purpose with proper ventilation and other safe guards.

Those safeguards include explosion proof ventilation to keep any leaks below 1.8% concentration, a NEMA 7, Div II electrical and spark free room, hydrocarbon alarms, and a fire suppression system.

 

[OG_TGR]

It is possible to extract indoors with a closed loop system, if it is a commercial building set up for the purpose with proper ventilation and other safe guards.

Those safeguards include explosion proof ventilation to keep any leaks below 1.8% concentration, a NEMA 7, Div II electrical and spark free room, hydrocarbon alarms, and a fire suppression system.

Excellent, thank you for clearing that up.
Is there by chance a hydrocarbon detector that you may recommend? Of course, something sensitive enough to detect well below the 1.8% concentration but still (hopefully) realistically affordable for a small scale production?
I see there are several available quite reasonably priced ($100-200) but I wonder if these are truly effective?
I would assume they would have to be of the catalytic or IR type sensors, as it seems to me that electrochemical sensors could pose an explosion risk due to their particular method of detection.
Would you have preference as to catalytic/IR type sensors?

Also, can anyone confirm my suggestion that nomenclature "N-butane" simply stands for the purity of the butane itself, differentiating it from the isomer of butane (thus Isobutane), which can contain butane and/or the propane isomer?

If so, what is the major difference in the end product, especially if there are suggestions of using propane as a solvent, and/or "pre-charging" a system with (2-methyl-propane?) propane?

 

[Rotel]

Excellent, thank you for clearing that up.
Is there by chance a hydrocarbon detector that you may recommend? Of course, something sensitive enough to detect well below the 1.8% concentration but still (hopefully) realistically affordable for a small scale production?
I see there are several available quite reasonably priced ($100-200) but I wonder if these are truly effective?
I would assume they would have to be of the catalytic or IR type sensors, as it seems that the nature of electrochemical sensors could pose an explosion risk by their particular nature.
Would you have preference as to catalytic/IR type sensors?

Also, can anyone confirm my suggestion that nomenclature "N-butane" simply stands for the purity of the butane itself, differentiating it from the isomer of butane (thus Isobutane), which can contain butane and/or the propane isomer?

If so, what is the major difference in the end product, especially if there are suggestions of using propane as a solvent, and/or "pre-charging" a system with (2-methyl-propane?) propane?

As to the n-butane / isobutane question, they are different molecules but both are c4h10 with isobutane having a lower boiling point. I'm sure gw can further elaborate.

 

[OG_TGR]

As to the n-butane / isobutane question, they are different molecules but both are c4h10 with isobutane having a lower boiling point. I'm sure gw can further elaborate.

I see. So N-butane is simply a structural isomer of butane? Would it possibly be the presence of 2-methyl-propane (also, apparently a structural isomer of butane) that allows for a lower boiling point?
It seems that isobutane would be more effective in extraction, allowing for more agitation at lower vacuum/higher ambient temperatures?
I assumed it was due to some sort of additional HCs in isobutane as opposed to N-butane, but I don't know if the structural difference in the isomers would be substantial enough to cause a significant health risk.

 

[OG_TGR]

Maybe this is going beyond the scope of this thread. Should I move these particular questions, possibly? I don't want to add fluff that isn't necessarily directly related to the BOHgart extractors.

 

[Rotel]

I'm on a phone so posting urls and stuff is a pain, simply google or wiki "isobutane" & "n-butane"

R-600 is n-butane
R-600a is isobutane

 

[OG_TGR]

(i-butane top, n-butane bottom)
Yes, I am aware of the chemical differences and descriptions but I cannot distinguish the qualities that makes one more applicable here, than the other.
I'd accept a realistic explanation from anyone, no need to feel obligated to answer directly.

 

[OG_TGR]

Found this:
https://www.icmag.com/ic/showthread.php?t=254417

(Iso vs N)

 

[GratefulOne]

Sorry, I should have been more specific. I wasn't picturing a literal overhead hood but rather an overall extraction intake as well as an articulating leg of a venturi driven (explosion proof) evacuation system.
So essentially it's a 10' tall, walk-in, grounded laminar flow hood, with an articulating, separately powered, venturi intake to directly vent line blow off into.
Overall ventilation is provided by a 2200cfm, 12" Mixed flow fan, mounted before the main venturi, and drawing from the outside, far from any exhaust point.
Second exhaust is powered by a 1000cfm mixed flow fan, also with a separate intake and venturi configuration.


Besides this, I'm reading here and there about propane as a pre-charge? Can anyone elaborate on this concept?

Check out a spray booth with a rear filter wall. If designed properly it will have full air flow from floor to ceiling.

You don't always have to use "explosion proof" blowers. Often a "hazardous location" blower will work depending on how you set it up. This saves some money.

Spray booths give a great first line of defense. You have a metal box everything is mostly contained in. The air flow keeps flumes out. You have a small simple space to install a fire suppression system.

 

[Breakover]

Excellent, thank you for clearing that up.
Is there by chance a hydrocarbon detector that you may recommend? Of course, something sensitive enough to detect well below the 1.8% concentration but still (hopefully) realistically affordable for a small scale production?
I see there are several available quite reasonably priced ($100-200) but I wonder if these are truly effective?
I would assume they would have to be of the catalytic or IR type sensors, as it seems to me that electrochemical sensors could pose an explosion risk due to their particular method of detection.
Would you have preference as to catalytic/IR type sensors?

Also, can anyone confirm my suggestion that nomenclature "N-butane" simply stands for the purity of the butane itself, differentiating it from the isomer of butane (thus Isobutane), which can contain butane and/or the propane isomer?

If so, what is the major difference in the end product, especially if there are suggestions of using propane as a solvent, and/or "pre-charging" a system with (2-methyl-propane?) propane?

Snap On combustible gas detector. On the most sensitive setting, it pegs out the detector on a bic lighter.

I think they run about $400, but they have a great warranty and are worth every penny, IMO.

http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=740545&group_ID=675544

 

[OG_TGR]

Check out a spray booth with a rear filter wall. If designed properly it will have full air flow from floor to ceiling.

You don't always have to use "explosion proof" blowers. Often a "hazardous location" blower will work depending on how you set it up. This saves some money.

Spray booths give a great first line of defense. You have a metal box everything is mostly contained in. The air flow keeps flumes out. You have a small simple space to install a fire suppression system.

Yep, that's pretty much the design I am building. I've already got the fans, just ordered static conductive duct (hopefully they will compensate for sticker shock!!, lol) and should have everything else on hand.

Snap On combustible gas detector. On the most sensitive setting, it pegs out the detector on a bic lighter.

I think they run about $400, but they have a great warranty and are worth every penny, IMO.

http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=740545&group_ID=675544

View Image

Awesome, thanks. I believe I saw you mention that on another thread, and I've had it in mind.

 

[vividavis]

I picked one up off of amazon for around $35. It is incredibly sensitive.

http://www.amazon.com/Eathtek-Portable-Refrigerant-Sensitivity-Assistant/dp/B00K9QLTP0/ref=sr_1_5?ie=UTF8&qid=1423768173&sr=8-5&keywords=halogen+leak+detector

 

[Lyfespan]

Look the blowing in a spray booth idea, perfect.

 

[GratefulOne]

If you are setting up an indoor location it requires an alarmed hydrocarbon sensor installed. The sensor will have to be rated explosion proof. You may be able to remove the alarm bell/siren from the immediate area (20 feet) and use non explosion proof. I have done this before and made the fire marshal happy while saving a ton of money.

The hand held units are nice for spot checks but to pass fire codes/insurance inspections you will need an installed unit.

 

[OG_TGR]

Hello everyone.
I received everything today and all looks good except that I seem to be having trouble getting all the way down to -30.
I can get to -26 without much issue but that seems to be about it. From there, I had it hold stead for an hour.
I went back and re-tightened to about two good squeaks, and it seems to be about the same thing.
I did not pressure test, as I have read, and think that I may need to try that.
How is it that I connect the compressor to the unit? I have a substantial compressor, but it's all quick connects.

Thanks!

Edit: I got it all figured out...first run done and it looks great!!!! Some weird things I came across, that I'll post tomorrow, after I get rest and go back through the thread again!

 

[GratefulOne]

Your elevation effects the vacuum reading. The higher you are the less atmosphere there is above you so the readings are lower.

Pressure test to at least 100 psi. Might check with GW on this one. I am sure he has the exact numbers calculated based on AMSE standards.

 

[OG_TGR]

Thanks! I think part of it was that I was pulling vacuum on the whole system, as opposed to just the chamber. With such volume, it's understandable that it would take longer, I think?

When I did it "right", it seemed much more inline where it should be.

I just did my first -10 "pour method", it's nice to be able to pour it out but that is just shady as hell, to me. I don't like being in that close of a proximity to that volume, that flammable/explosive.

 

[Gray Wolf]

Your elevation effects the vacuum reading. The higher you are the less atmosphere there is above you so the readings are lower.

Pressure test to at least 100 psi. Might check with GW on this one. I am sure he has the exact numbers calculated based on AMSE standards.

ASME requires actual failure at least 3X the maximum operational load, but we test for leaks at 100 psi.

 

[Fazer1HashTrees]

I'm only getting to -24.5hg but I'm a mile high above sea level so that seems right for my elevation. Gonna try the first run after all this snow melts.