Help Bho Vacuum Chamber Questions

[Graywolf]

Won't that burn the pump up..wouldn't it be just the same if it was under pressure and could stay that way

A vacuum oven requires a 100% duty cycle pump.

It doesn't stay under pressure when you stop the pump, it slowly decays as the volatiles vaporize.

 

[207north]

So by leaving the vac on it will suck the butane out without having to keep opening the chamber...should I be opening every so often ...and there isn't a time frame for how long you vecuum purge just until there is no more activity right? Thank you guys again it awesome to have ppl answer my question

 

[CelticEBE]

Won't that burn the pump up..wouldn't it be just the same if it was under pressure and could stay that way

While you are still holding a vacuum, you aren't actively pulling on it unless you keep the pump running.

I used to shut my pump off, and now my purge times have shortened a great deal by keeping it running.

Make sure your oil levels are good and you will be fine.

 

[Graywolf]

So by leaving the vac on it will suck the butane out without having to keep opening the chamber...should I be opening every so often ...and there isn't a time frame for how long you vecuum purge just until there is no more activity right? Thank you guys again it awesome to have ppl answer my question

I bring the material up to temperature in the chamber/oven and then start the vacuum. I hold at a vacuum level that causes furious boiling until it subsides and then continue pulling down until I reach -29.5 without furious boiling and then back fill with nitrogen, remove and flip, before repeating until I reach -29.5 Hg and there are no solvent bubbles left, only occasional small fizzy CO2 bubbles.

 

[TwisTer46290]

A vacuum oven requires a 100% duty cycle pump.

It doesn't stay under pressure when you stop the pump, it slowly decays as the volatiles vaporize.

A decent vacuum chamber will hold it's pressure and slowly decrees, in which a pump can be turned on again. What' the reasoning ( scientifically), besides speeding up the process, as to why one should leave a pump on 24/7 vs not?

 

[EugeneOregon]

A decent vacuum chamber will hold it's pressure and slowly decrees, in which a pump can be turned on again. What' the reasoning ( scientifically), besides speeding up the process, as to why one should leave a pump on 24/7 vs not?

I have some of the best vacuum chambers there are in a multitude of forms. In a sense any short path head is also a vacuum chamber. I have viton sealed sublimator units that hold deep vacuum to less than one micron and I also have a Scientific bell jar vacuum chamber mounted on a thick steel plate and sealed with polymer rubber. I use a Pirani based graphing vacuum gauge to monitor.

In every case once the vacuum pump ceases to continue evacuating gas molecules any configuration I mentioned above immediately begins to climb irregardless of whether anything is in it or not. This is of course called a leak down phase and monitoring it can indicate problems if they exist. All chambers typically leak down within three minutes or so from one micron to hundreds. Several more minutes and normally they tend to plateau somewhere around 1500 microns. My Pirani based sensor begins losing accuracy up in that range and above but normally a tight scientific chamber will hold at 2000 microns overnight. This is with nothing in them as a sample.

The reason is pretty simple. We cannot prevent the really small gas molecules present in our atmosphere from penetrating the permeable seals used in the polymers at the system joints. Greased joints might be great but at some point in the vacuum system there are polymer seals and hoses used out of necessity. The key is mitigation and limiting the length of polymer hose to just what is necessary and limit joints also to only the minimum needed helps mitigate the problem. Polymers themselves also outgas and all polymers are permeable.

Now when you place anything that by itself evolves gas into a chamber then the laws of physics are what they are. More gas equals more pressure. More pressure over time equals less vacuum unless you are removing on a continuous basis at least the exact amount of gas being evolved plus the inherent leakage present as mentioned above. So why leave the pump on instead of on and off as the pressure cycles up far enough once the pump is off?

Simple. The vast majority of wear and tear under normal usage in an electric motor is the start up cycle. When you fire up a big motor normally you will notice lights on the same circuit will dim a bit. Sometimes a UPS power supply on the same circuit will beep. This is because until the motor spins up to 3450 rpm at 60 hertz the motor windings draw far more current than they do when up to speed. This extra current is converted to heat and also dims your room lights momentarily if they are on the same circuit. While you see that momentary dimming of lights when the pump comes on, what is happening inside the motor windings is that they are getting VERY hot during that time. So they go from cool then to very hot during start up. Metals all expand and contract as they cool and heat and metal windings are simply very, very long metal wires. They expand and contract too with heat changes and they rub against each other slightly as they change dimensions because of the thermal change. This mechanically wears them out over time whereas if they stay at the same temperature then there is no mechanical wear this way. Other parts of the motor also suffer from this heating cycle but you get the idea.

You might also notice circuit breaker problems with repeated restarts for the same reason. Most circuit breakers operate on heat flexing a metal strip. When too much current flows the metal heats up and at a point it trips like a mouse trap because it expands enough as designed to do this. On the first start up the breaker will get hot but not trip. If however it is still hot when the next startup of the motor happens then it might well start to trip. This protects house wiring but would certainly be a real issue to solve.

 

[TwisTer46290]

I have some of the best vacuum chambers there are in a multitude of forms. In a sense any short path head is also a vacuum chamber. I have viton sealed sublimator units that hold deep vacuum to less than one micron and I also have a Scientific bell jar vacuum chamber mounted on a thick steel plate and sealed with polymer rubber. I use a Pirani based graphing vacuum gauge to monitor.

In every case once the vacuum pump ceases to continue evacuating gas molecules any configuration I mentioned above immediately begins to climb irregardless of whether anything is in it or not. This is of course called a leak down phase and monitoring it can indicate problems if they exist. All chambers typically leak down within three minutes or so from one micron to hundreds. Several more minutes and normally they tend to plateau somewhere around 1500 microns. My Pirani based sensor begins losing accuracy up in that range and above but normally a tight scientific chamber will hold at 2000 microns overnight. This is with nothing in them as a sample.

The reason is pretty simple. We cannot prevent the really small gas molecules present in our atmosphere from penetrating the permeable seals used in the polymers at the system joints. Greased joints might be great but at some point in the vacuum system there are polymer seals and hoses used out of necessity. The key is mitigation and limiting the length of polymer hose to just what is necessary and limit joints also to only the minimum needed helps mitigate the problem. Polymers themselves also outgas and all polymers are permeable.

Now when you place anything that by itself evolves gas into a chamber then the laws of physics are what they are. More gas equals more pressure. More pressure over time equals less vacuum unless you are removing on a continuous basis at least the exact amount of gas being evolved plus the inherent leakage present as mentioned above. So why leave the pump on instead of on and off as the pressure cycles up far enough once the pump is off?

Simple. The vast majority of wear and tear under normal usage in an electric motor is the start up cycle. When you fire up a big motor normally you will notice lights on the same circuit will dim a bit. Sometimes a UPS power supply on the same circuit will beep. This is because until the motor spins up to 3450 rpm at 60 hertz the motor windings draw far more current than they do when up to speed. This extra current is converted to heat and also dims your room lights momentarily if they are on the same circuit. While you see that momentary dimming of lights when the pump comes on, what is happening inside the motor windings is that they are getting VERY hot during that time. So they go from cool then to very hot during start up. Metals all expand and contract as they cool and heat and metal windings are simply very, very long metal wires. They expand and contract too with heat changes and they rub against each other slightly as they change dimensions because of the thermal change. This mechanically wears them out over time whereas if they stay at the same temperature then there is no mechanical wear this way. Other parts of the motor also suffer from this heating cycle but you get the idea.

You might also notice circuit breaker problems with repeated restarts for the same reason. Most circuit breakers operate on heat flexing a metal strip. When too much current flows the metal heats up and at a point it trips like a mouse trap because it expands enough as designed to do this. On the first start up the breaker will get hot but not trip. If however it is still hot when the next startup of the motor happens then it might well start to trip. This protects house wiring but would certainly be a real issue to solve.

So to quickly sum up everything in your very nice detailed comment

✔All chambers loose vac, till they even out, unless under constant vac

✔Chambers, while loosing vac, can bring in airborne contaminatents

✔Seals of chambers can off gas into contents within chamber

✔Continuing to vac will stop all the newly purged gas from taking away from chamber pressure

✔Help prevent wear and tear on pump

✔Be a little easier on the circuit breaker

I'm sure I over looked or didn't mention a couple things, I'll surely reread it a few more times, lol.

I'm left with a few more questions if you don't mind

1. Will that gas that was purged from the concentrate somehow re-combined with the concentrate if left in the chamber with out vac over time?

2. Chambers can off gas into are concentrate!?

3. Is it really easier on the pump to leave it on for 3 days, then to turn in on and off twice a day?
If this is so I really screwed up when I returned my oiless Rocker 500 ( Which I could only almost get to -28) for a Yellow Jacket 8cfm 2stage, which is really loud in comparison ( but can get to 29.5, kinda taking a while)

 

[EugeneOregon]

So to quickly sum up everything in your very nice detailed comment

✔All chambers loose vac, till they even out, unless under constant vac

✔Chambers, while loosing vac, can bring in airborne contaminatents

✔Seals of chambers can off gas into contents within chamber

✔Continuing to vac will stop all the newly purged gas from taking away from chamber pressure

✔Help prevent wear and tear on pump

✔Be a little easier on the circuit breaker

I'm sure I over looked or didn't mention a couple things, I'll surely reread it a few more times, lol.

I'm left with a few more questions if you don't mind

1. Will that gas that was purged from the concentrate somehow re-combined with the concentrate if left in the chamber with out vac over time?

2. Chambers can off gas into are concentrate!?

3. Is it really easier on the pump to leave it on for 3 days, then to turn in on and off twice a day?
If this is so I really screwed up when I returned my oiless Rocker 500 ( Which I could only almost get to -28) for a Yellow Jacket 8cfm 2stage, which is really loud in comparison ( but can get to 29.5, kinda taking a while)

1. I suppose it would leave a terp taste of sorts that would stand out if trying to make pure isolate but I doubt it would matter much otherwise.

2. My bell chamber which shipped to me with a soft polymer matt as a seal to the metal plate absolutely outgassed enough the first two or three days of continuous vacuum, pumping down twice a day to one micron then sealing the valve, to contaminate a sample. It made the sample in the chamber smell and taste slightly like..... rubber. Hehe. I ran the isolate again in a sublimator to remove the odor. After long time use though the out gassing of that rubber matt is no longer noticeable or a problem.

3. There is no way two cycles a day will hurt the unit at all in contrast to continuous running in my opinion. I was speaking more towards several cycles per hour. Here is a link
I found that explains it pretty well.

 

[TwisTer46290]

1. I suppose it would leave a terp taste of sorts that would stand out if trying to make pure isolate but I doubt it would matter much otherwise.

2. My bell chamber which shipped to me with a soft polymer matt as a seal to the metal plate absolutely outgassed enough the first two or three days of continuous vacuum, pumping down twice a day to one micron then sealing the valve, to contaminate a sample. It made the sample in the chamber smell and taste slightly like..... rubber. Hehe. I ran the isolate again in a sublimator to remove the odor. After long time use though the out gassing of that rubber matt is no longer noticeable or a problem.

3. There is no way two cycles a day will hurt the unit at all in contrast to continuous running in my opinion. I was speaking more towards several cycles per hour. Here is a link
I found that explains it pretty well.

Thank you very much for your replies!

I did not mean to disregard your mouse trap example by re-asking the question. Just in my mind, if I continue to pull back on a mouse trap, both sides like breaking a stick, it would snap, I guess that would be an example of over heating that I've been concerned of.
Truthfully, I will take the best care of my tools that I can, but eventually they'll break. My main concern is my health, this is something that I cannot replace. Due to concentrates being so expensive and flower is starting to catch up in my lungs more quickly due to needing a higher potency, I've had to revert to making my own medicine. I just want to be sure I'm able to make my personal as clean as the pros!

I also used one of those non stick pads that came with my first chamber. Rubbed it down with alcohol and then hot soap and water. Still made the inside of the chamber smell funky. I'm going to have to stick to organic parchment paper just to stay safe, plus I feel it hasn't stuck to it as much!
Much peace and respect!

 

[EugeneOregon]

Thank you very much for your replies!

I did not mean to disregard your mouse trap example by re-asking the question. Just in my mind, if I continue to pull back on a mouse trap, both sides like breaking a stick, it would snap, I guess that would be an example of over heating that I've been concerned of.
Truthfully, I will take the best care of my tools that I can, but eventually they'll break. My main concern is my health, this is something that I cannot replace. Due to concentrates being so expensive and flower is starting to catch up in my lungs more quickly due to needing a higher potency, I've had to revert to making my own medicine. I just want to be sure I'm able to make my personal as clean as the pros!

I also used one of those non stick pads that came with my first chamber. Rubbed it down with alcohol and then hot soap and water. Still made the inside of the chamber smell funky. I'm going to have to stick to organic parchment paper just to stay safe, plus I feel it hasn't stuck to it as much!
Much peace and respect!

Here is my latest art for you lolz. The compound is Delta 9 THC isolated to near absolute. This is just off the cold finger out of deep vacuum. I used the art app to highlight the compound and darken areas around it and it really pulled out the cool colors. The light really plays on the stuff. Deep vacuum and absolutely molecularly clean environment produce this compound. Knowing your vac system is everything. I hope you like it. I vaped nearly all of it and today is the last bit loaded just now as posting. Life is good.

 

[TwisTer46290]

Here is my latest art for you lolz. The compound is Delta 9 THC isolated to near absolute. This is just off the cold finger out of deep vacuum. I used the art app to highlight the compound and darken areas around it and it really pulled out the cool colors. The light really plays on the stuff. Deep vacuum and absolutely molecularly clean environment produce this compound. Knowing your vac system is everything. I hope you like it. I vaped nearly all of it and today is the last bit loaded just now as posting. Life is good. View attachment 795886

Nice, I have some ChemDawg prepin I'm extremely excited for over here!