Combustion or Ignition---thoughts anyone?

[BckYrdBBQr]

combustion??? ----- ignition??

an interesting exchange was happening in "legislation and news" ....I have moved it here since this is probably a more appropriate place.

let's have it......

 

[Uncle Screwtape]

more like Percolation.

 

[Zal42]

Well, to continue the discussion from the other thread, which was about whether or not vaping involves combustion.

Combustion is an exothermic (heat-producing) process that results from a chemical reacting with an oxidizer. Ignition is what starts the combustion process.

vaping does not involve either combustion or ignition. No combustion, as there is no exothermic chemical reaction going on. No ignition, because there's no combustion.

vaping is using heat externally applied by our atomizers to boil the juice and cause it to evaporate, in other words, to change from a liquid to a gas. No oxidization, no exothermic reaction, no combustion. It is the same process as boiling water to create steam, which is also not combustion.

 

[BckYrdBBQr]

Joule heating, also known as ohmic heating and resistive heating, is the process by which the passage of an electric current through a conductor releases heat. It was first studied by James Prescott Joule in 1841. Joule immersed a length of wire in a fixed mass of water and measured the temperature rise due to a known current flowing through the wire for a 30 minute period. By varying the current and the length of the wire he deduced that the heat produced was proportional to the square of the current multiplied by the electrical resistance of the wire
It is now known that Joule heating is caused by interactions between the moving particles that form the current (usually, but not always, electrons) and the atomic ions that make up the body of the conductor. Charged particles in an electric circuit are accelerated by an electric field but give up some of their kinetic energy each time they collide with an ion. The increase in the kinetic or vibrational energy of the ions manifests itself as heat and a rise in the temperature of the conductor. Hence energy is transferred from the electrical power supply to the conductor and any materials with which it is in thermal contact.

Joule heating is referred to as ohmic heating or resistive heating because of its relationship to Ohm's Law. It forms the basis for the myriad of practical applications involving electric heating.

 

[Scootypuff]

Dude, heat is not the same thing as fire.

 

[Chornbro]

Well, to continue the discussion from the other thread, which was about whether or not vaping involves combustion.

Combustion is an exothermic (heat-producing) process that results from a chemical reacting with an oxidizer. Ignition is what starts the combustion process.

Vaping does not involve either combustion or ignition. No combustion, as there is no exothermic chemical reaction going on. No ignition, because there's no combustion.

Vaping is using heat externally applied by our atomizers to boil the juice and cause it to evaporate, in other words, to change from a liquid to a gas. No oxidization, no exothermic reaction, no combustion. It is the same process as boiling water to create steam, which is also not combustion.

ding ding ding!! /thread

 

[IOU]

Okay subscribed! This could be a really interesting thread!

 

[Chornbro]

Okay subscribed! This could be a really interesting thread!

Unfortunately theres not a whole lot to discuss... at least I dont think? Well... that I think about it... it's possible that the coils get so red hot that they burn certain parts of your juice... some juices have sugar-based flavorings in them which definitely burn at a relatively low temperature. Hell, I'm in too

 

[Scootypuff]

Does this guy seriously not know why every electrically wired home in existence does not spontaneously combust?

 

[BckYrdBBQr]

combustion does not always mean fire.

 

[Zal42]

combustion does not always mean fire.

Conversely, the application of heat (even extreme heat) does not always mean combustion.

Very slow combustion can happen and there is no flame, but it is still a heat-producing chemical reaction and the chemicals reacting with the oxidizer still become other chemicals as a result of the combustion. This is simply not what's going on in our vaporizers.

Now, it's possible to make it happen. If you run an atty dry, I suppose that a small amount of combustion could take place, but that's a degenerate condition, and one that vapers quickly learn to avoid.

 

[jlarsen]

I agree, there is, or at least should not be any combustion or ignition going on in a PV. However, what about endothermic reactions? Could there be endothermic reactions going on? Possibly. There could also be slow combustion with sweeteners, maybe even flavors, especially when attys are dry burned or not wicking properly. I wouldn't use a high voltage PV, because I hear so many getting a burnt taste. I've never gotten a burnt taste with a 3.7 volt battery. I've seen pictures of burnt wicking material, but I've never seen any in my components.

The PG and VG in a regular voltage PV are neither combusting or igniting, it would take temps around 700F, and a properly wicked atty isn't reaching those temps. Ejuice is not a fuel, the battery is the energy source, PG and VG only ignite at very high temps. Much like water boiling on a stove, vaping is a simple physical reaction, not a chemical one.

 

[Zal42]

I agree, there is, or at least should not be any combustion or ignition going on in a PV. However, what about endothermic reactions?

Perhaps, I don't know, but that is not combustion.

There could also be slow combustion with sweeteners, maybe even flavors, especially when attys are dry burned or not wicking properly.

This is possible, I suppose, but the amount of combustion would be so tiny as to be insignificant. Also, I wonder how much oxidizer is present in the juice? I can't see that there's much, if any. pg & vg contain no oxidizer, or at least far below 1%. Without an oxidizer there can be no combustion regardless of what the composition is. Dry burning is different, as the coil is exposed to the air, which contains plenty of oxidizer.

 

[jlarsen]

Perhaps, I don't know, but that is not combustion.



This is possible, I suppose, but the amount of combustion would be so tiny as to be insignificant. Also, I wonder how much oxidizer is present in the juice? I can't see that there's much, if any. pg & vg contain no oxidizer, or at least far below 1%. Without an oxidizer there can be no combustion regardless of what the composition is. Dry burning is different, as the coil is exposed to the air, which contains plenty of oxidizer.

Isn't the coil exposed to air as you inhale?

 

[Zal42]

Isn't the coil exposed to air as you inhale?

It shouldn't be, unless you have wicking problems. The coils should always be wet, emitting vapor which then flows to the air channel.

 

[jlarsen]

It shouldn't be, unless you have wicking problems. The coils should always be wet, emitting vapor which then flows to the air channel.

Right, the coil is wet, but it is in the opening of the air chamber, so you have fresh 02 flowing past it as it is releasing vapor. It shouldn't be a problem, but technically there is plenty of air, plenty of oxygen getting to the coil, though maybe not touching it directly.

 

[SteveMacc]

Don't vape where there are inflammable materials. You e-cig could start a fire. PG and VG are inflammable. Try heating some on a teaspoon over a gas flame. Same effect as heating brandy, which is not surprising as PG and VGare both types of alcohol.

Here is a you tube video illustrating the effect. I've done this too.

YouTube - Bulli-A1 Atomizer on Fire !

 

[Higbe33]

fire - a chemical chain reaction with the evolution of heat and light. At least that's what they taught us in fire science. Steam will turn back into water. Will our vapor still be VG/PG, nicotine and flavoring? If yes, then I go with it just reached its boiling point and would not be combustion.

 

[fuzznut]

If our e-cigs operated with 100% physical reaction, our attys and cartos would last forever. So where does that buildup of crud on the coil come from that makes us toss our cartos and dry burn our attys?

 

[Wuzznt Me]