Charring vs combustion

[Prof77]

I have used my Solo for ages and never ever had more than a slight dark brown color of herb at opening of stem where it contacts Solo's heater no matter the temp or how much is packed into stem, however I get black top with my Air most every time I use it and on most temp settings. Is my new Air working improperly or am I the bad robot here?

 

[olivianewtonjohn]

I find it hard to believe that any arizer product is turning your herb black. Are you sure it's not just really, really dark brown? Black = combustion. If it really is blackening then it needs returning under warranty.

As @VANVAS already said, it may be due to less air flow with your arizer air meaning the load doesn't cool so much when you take a hit.

Black=combustion? I thought ash=combustion. On 7 my solo would turn it black but definitely not combustion

 

[salivape]

Black=combustion? I thought ash=combustion. On 7 my solo would turn it black but definitely not combustion

That's what I was always led to believe. I'll gladly eat my hat though...

If you burn your dinner it smokes and goes black before it catches fire and turns to white ash so I'd imagine the same would apply for cannabis?

 

[MeditativeMind]

I'd be more interested in any units they didn't approve, at this point.

Uh... okay.....

That's what I was always led to believe. I'll gladly eat my hat though...

If you burn your dinner it smokes and goes black before it catches fire and turns to white ash so I'd imagine the same would apply for cannabis?

Black = charred = combustion occurred.

 

[salivape]

Black = charred = combustion occurred.

That's what I figured. I've never had black bud in any arizer vape, but it does go REALLY dark brown by the heater.

 

[olivianewtonjohn]

That's what I was always led to believe. I'll gladly eat my hat though...

If you burn your dinner it smokes and goes black before it catches fire and turns to white ash so I'd imagine the same would apply for cannabis?

But "burning" your dinner is not equivalent to combustion. It would take a lot of heat to make your steak combust compared to browning it. Or compared to making bread combust. This is due to the bonds of the food. With MJ there is a narrower range, it combusts at a lower temperature. Ash is a byproduct of combustion. If you are not getting ash then I don't believe combustion is occurring.

 

[salivape]

But "burning" your dinner is not equivalent to combustion. It would take a lot of heat to make your steak combust compared to browning it. Or compared to making bread combust.

It still produces smoke though right? I'm not sure what the scientific definition of combustion is but in the vaping sense anything that smokes is something we don't want to be inhaling.

 

[olivianewtonjohn]

It still produces smoke though right?

Smoke and steam are two very different things. Smoke implies co2 formation ie combustion. there is a lot of water in steaks so you will have a lot of steam. As far as browning,I just googled and it turns brown as myoglobin reacts to the heat (oxydation of iron)

 

[salivape]

Yeah I know that, give me some credit . There's no way in hell that the thick grey "smoke" that comes from burnt/charred food is steam. There's just no way. Charring happens after any moisture in the food/weed is gone.

Steam doesn't make a fire alarm go off....

 

[olivianewtonjohn]

Yeah I know that, give me some credit . There's no way in hell that the thick grey "smoke" that comes from burnt/charred food is steam. There's just no way. Charring happens after any moisture in the food/weed is gone.

Steam doesn't make a fire alarm go off....

Good point.....lots of googling around turned up maillard reaction which is browning of food. But food and MJ are different animals, made up of different compounds which likely lies the answer.

Going back to the main point, if your MJ was getting hot enough to combust, what are the chances that it would not catch on fire producing a ton of smoke and ash? Seems extremely unlikely or impossible to me

Edit: if I'm wrong about black material=/=combustion, then could someone please correct me.

 

[WoodVillain]

I've never had black bud in any arizer vape, but it does go REALLY dark brown by the heater.

I get black "tops" where the herb is closest to the heater when i go a while on red temp setting. I dont mind... But then again im no stranger to, or hater of, combustion anyways.

But with the Arizer EQ.... I have had the herb combust, turn glowing red and BURN the herb to ash... On the highest heat setting and on fan 3.. It was just a test to see if it would do it, and it did... Had to throw that bag away LOL

Edit... Dont take that the wrong way though, i love the EQ. No reason to ever NEED to run it to 260°C.... Its cool they give you the option... But im not sure why anyone would need to go that high.

 

[al bundy]

Same here with the EQ.

A 5/8in screen in the Solo/Air bowl will help that.
Ive had that before too.
Its black but didnt combust,just well done ABV,

 

[OF]

I also feel that , i think can be the very good seal with the 4 o rings from the air, makes no loss of temp. Can be an option...
Can anyone tell something about?
Another thing running in my head is ( sorry if is answered ) AA temperature osillates? I mean like the solo , always checking temp. with sensors...
Anyone knows ?

Yes. Air and Solo work basically the same. Four leads to the oven, two for power, two to sense temperature. This way losses from making vapor and heating air can be compensated for. The sensor is inside the assembly, most likely bonded to the SS cup.

Yes, the seal is excellent. However no o-rings. First is a molded flat seal, then 3 ribs in a plastic body.....bumps on the wall if you will?

Black = charred = combustion occurred.

No, that's not true. Black doesn't mean combustion. Black means black, usually by charring, but ironically often it's actually proof combustion didn't happen. Charcoal would be an example. Once wood products, charred and pressed, awaiting combustion on your command. Black and charred, but not yet combusted. When it is, it'll be much lighter and gray ash.

Combustion is a chemical process, not a physics issue. It means chemical reaction(s) happening and different molecules than were there before. And it liberates heat, which is how we get into trouble with it, once stated as long as there's air there, it makes it's own heat to keep going (and grow if it can). Very different than using physics to separate out the good stuff by evaporation (vaping).

Black material in your ABV is proof you got it hotter than you probably wanted to (at least at that point). But a little or a lot isn't proof of combustion. Ash would be since it didn't exist before the adventure.

Or so they taught me when the world was new.

OF

 

[stark1]

"Combustion"?

What is that.

 

[olivianewtonjohn]

@OF and @steama

But isn't charring a type of combustion? Wiki is saying it's incomplete combustion, which from my understanding almost every combustion reaction is incomplete

 

[olivianewtonjohn]

Combustion is a chain reaction. If there is no chain reaction there is not combustion. Incomplete combustion means a chain reaction of combustion never occurred.

I look at combustion as a barrier in the art of vaping. Combustion is not when I open a vape and see dark charring — that is too much heat. Combustion is when I have started the chain reaction for fire. I have actual burning and smoke and a chain reaction has begun. In vaping this is usually manifest by a burning, smoking, ember, in your once favorite vape's bowl.

Incomplete combustion means we are left with something like coal or ash. Perhaps less reactions but given the charing name still combustion. Honestly confusing for me since its exothermic reaction once started shouldn't stop until there is no more oxygen As OF Said.

 

[OF]

Combustion has two factors of interest I think. First is it's chemical reactions, atoms changing partners, usually "exothermic", that is giving up heat. In some combustions individual reactions can be "endothermic" as I recall, but they are short lived. The major reactions involve oxygen combining with carbon and hydrogen in the end, making water and CO2.

Not all such oxidations are combustion. It depends on the rate. A bit like trying to get a damp campfire going, once you get the point heat is getting trapped and starting more reactions faster than it's escaping you're off to the races. As Steama's colorful chart above shows it's chain reaction time, take away the heat and it still runs. Like in you car, once that spark hits, the gasoline and air in the cylinder are going to burn (combust) without further control/input.

Or so was taught.

Once the bong is lit, the cherry keeps it going.

That I had to learn on my own......

OF

 

[olivianewtonjohn]

@steama

"However, complete combustion is almost impossible to achieve, since the chemical equilibrium is not necessarily reached, or may contain unburnt products such as carbon monoxide, hydrogen and even carbon (soot or ash). "

http://en.wikipedia.org/wiki/Combustion

"To reduce to carbonorcharcoal by incomplete combustion.See Synonyms at burn1."

http://www.thefreedictionary.com/charring

And

"Charring is a chemical process of incomplete combustion of certain solids when subjected to high heat."
http://en.wikipedia.org/wiki/Charring

Now when I search for incomplete combustion, many sources give a definition exactly like what you are saying, limited resources=incomplete combustion. So in this case we have plenty of fuel and plenty of oxygen but not enough heat.

I think what you are saying makes a lot of sense compared to what these definitions seem to imply. Thank you for the discussion very interesting, and @OF thanks for the informative post (as usual).

 

[Prof77]

Blackened top update: I have the black air and was using it with the black sleeve. I removed the sleeve yesterday and the unit now feels substantially cooler when operating[maybe cause black retains heat and the sleeve covers the slits at the top] and the herb at top now has only a tiny black spot in center of dark brown spot - this was on the green and next lower settings.

This is a substantial improvement over the completely black and charred appearance of the whole top of the herb in the stem.

 

[rebelxd]

I sometimes get some almost black herb nearest the heater on the air, didn't think much of it

 

[stark1]

Okay. If I read any more combustion vs charring heat, I am gonna combust!

Luckily, I lack oxygen, so, I haven't got a leg to stand on.

I do have some spliff.....

 

[KeroZen]

Besides agreeing on the exact term, I think that some people here are worried that incomplete combustion is a sign that pyrolisis happened (ie heat broke chemical compounds appart, possibly creating new byproducts in the process, said byproducts are often "free radicals" and they try to combine with everything they touch because they shouldn't exist in this state... and most often they are carcinogens)

So while it might not be a real combustion, I still think we want to avoid charring for health safety reasons.

 

[max]

Black = charred = combustion occurred.

Sorry. That's wrong. I've 'high temped' many a vape bowl over the last 10 years, and dumped out blackened ABV many times, but only combusted a few times. My throat and lungs know the difference between even high temp vapor and smoke.

Charring does not mean combustion. Incomplete combustion does not mean combustion. Incomplete means all the factors (of the fire triangle) were not present to produce combustion or fire.

Combustion means fire has started.

 

[olivianewtonjohn]

Besides agreeing on the exact term, I think that some people here are worried that incomplete combustion is a sign that pyrolisis happened (ie heat broke chemical compounds appart, possibly creating new byproducts in the process, said byproducts are often "free radicals" and they try to combine with everything they touch because they shouldn't exist in this state... and most often they are carcinogens)

So while it might not be a real combustion, I still think we want to avoid charring for health safety reasons.

Thats what I was thinking about last night actually. If charring is actually incomplete combustion then bonds are still being broken and reformed:

But the thing is even if some radicals are released; the amount would be alot less than complete combustion. And given the fact that even combustion of weed seems pretty harmless when compared to tobacco; ill continue to vape my bowls very thoroughly

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1277837/

 

[olivianewtonjohn]

Help! This water's getting deep!

Its funny everytime I think it starts to make sense it doesnt LOL.

Here is what I was thinking based on what you posted:

So we have fuel and we have oxygen but not enough heat. If we increase heat, combustion occurs (shocker). Now the chemical equation I posted above seems like its for situations with lower amounts of oxygen (smothered and hot), thats one way to make coal; heating and smothering the wood to char it. Now I cant really find anything about the chemistry of low temp charring, I am curious if the equation would be different and if so how. Here is what I found though; perhaps charring is the beginning stages of this:

Smouldering/Slow[edit]
Smouldering is the slow, low-temperature, flameless form of combustion, sustained by the heat evolved when oxygen directly attacks the surface of a condensed-phase fuel. It is a typically incomplete combustion reaction. Solid materials that can sustain a smouldering reaction include coal, cellulose, wood, cotton, tobacco, peat, duff, humus, synthetic foams, charring polymers (including polyurethane foam), and dust. Common examples of smouldering phenomena are the initiation of residential fires on upholstered furniture by weak heat sources (e.g., a cigarette, a short-circuited wire) and the persistent combustion of biomass behind the flaming fronts of wildfires.

http://en.wikipedia.org/wiki/Combustion