Atomizer temperatures unreasonably high

[Chriskarr]

Hello all,

I know this probably isn't the best place to post this, but I am currently limited as to my options.

I have been doing research on nicotine delivery and the efficiency of our devices, lately, and I've come up with some questions as to why we do the things we do.

It appears that 300ºC is about the floor temperature for nicotine's thermal decay in open, oxygenated air.

"In general, these studies indicate that nicotine is stable in inert atmospheres up to temperatures in excess of 600°C.31-33 In an oxidizing atmosphere, i.e., in air, nicotine begins to decompose at ca. 300°C"

Thermal Properties of Nonprotonated and Protonated Nicotine. The Contrast of Nicotine's Transfer to Smoke with the Mechanism of ....... 'freebasing'

Wikipedia lists the vaporization (boiling) point of nicotine at 247ºC.

As such, shouldn't the target temperature for our *dry* coils be ~320ºC?

Our silica wicks burn and break due to the heat of our coils. Since we know they truly burn, that means they must at times achieve temperatures in excess of 1,800ºF. Nichrome's temperature stability extends to 2,000ºF+, so this isn't unreasonable. If we were to lower the temperature of our coils we could greatly extend atomizer life and prevent excessive decay of the nicotine in our e-cigs.

Any comments or thoughts are welcome.

 

[Robino1]

Hello all,

I know this probably isn't the best place to post this, but I am currently limited as to my options.

I have been doing research on nicotine delivery and the efficiency of our devices, lately, and I've come up with some questions as to why we do the things we do.

It appears that 300ºC is about the floor temperature for nicotine's thermal decay in open, oxygenated air.

"In general, these studies indicate that nicotine is stable in inert atmospheres up to temperatures in excess of 600°C.31-33 In an oxidizing atmosphere, i.e., in air, nicotine begins to decompose at ca. 300°C"

Thermal Properties of Nonprotonated and Protonated Nicotine. The Contrast of Nicotine's Transfer to Smoke with the Mechanism of ....... 'freebasing'

Wikipedia lists the vaporization (boiling) point of nicotine at 247ºC.

As such, shouldn't the target temperature for our *dry* coils be ~320ºC?

Our silica wicks burn and break due to the heat of our coils. Since we know they truly burn, that means they must at times achieve temperatures in excess of 1,800ºF. Nichrome's temperature stability extends to 2,000ºF+, so this isn't unreasonable. If we were to lower the temperature of our coils we could greatly extend atomizer life and prevent excessive decay of the nicotine in our e-cigs.

Any comments or thoughts are welcome.

Sorry I can't help you with any of that.....my brain hurts now LOL

Hope you find your answers.

 

[DC2]

Our silica wicks burn and break due to the heat of our coils. Since we know they truly burn, that means they must at times achieve temperatures in excess of 1,800ºF.

I know many people believe it does, but the silica wick does not burn.

It does get caked up with burnt juice components, but you can burn all that off at high temperatures.
That is known as dry burning, and it is basically the same concept as a self-cleaning oven.

Or if you take your atomizer apart, you can flake little gunk pieces off of the wick.
I think this is where a lot of people get the idea that the wick burns.

As far as I'm concerned, the idea that the silica wick material burns is one of the biggest vaping myths.

 

[DC2]

Oh, and there are a lot of people who do know what temperature our coils operate at.
I'm sure one of them will be by shortly with an answer.


EDIT: I personally do not remember the temperature.
EDIT: But I do know it is generally UNDER the temperature needed to produce acrolein.

 

[KuroCz]

Weeelll....

I'm not concerned with the melting point of nichrome wire or it's temp stability threshold or what it likes for dinner on wednesday nights All I know is that on a boge 2.9ohm carto @4.6volts, this juice tastes awsome to me. And as a 18mg juice, if I want more , I'll take another hit. I have 24mg juice coming tomorrow

 

[Chriskarr]

@DC2

Yes, but that's during proper, general use with a wet wick. If it couldn't produce acrolein, then why do we get black deposits in the first place?

Do vapers get black deposits with unflavored liquid?

 

[DC2]

@DC2

Yes, but that's during proper, general use with a wet wick. If it couldn't produce acrolein, then why do we get black deposits in the first place?

Do vapers get black deposits with unflavored liquid?

I believe the vast majority of the deposits (baked on gunk) comes from flavoring and coloring components.
And I'm really glad you posted this thread and I'm looking forward to seeing where it goes.

 

[AttyPops]

It's a good point... and so is boiling water in a paper cup in physics/chem class. Keep the wick wet is all I know.

+1 on DC2's comment about not producing acrolein so also not melting wicks and/or resistance coil.

It is an interesting concern... particularly with vv devices. I hope we get more testing on various devices and coils.

 

[Chriskarr]

Great. A google search's first result for 'unflavored liquid black deposit' is this thread..

Looks like we're blazing trails, here, gentlemen.

Here's a thread I found which analyzes the black gunk: http://www.e-cigarette-forum.com/fo...12335-analysis-black-gunk-atomizer-coils.html

The charts in exogenesis's post show a large amount of carbon and a small amount of nitrogen, both of which exist in nicotine molecules. It's not proof positive that nicotine decay on the coil is an issue, but it's sufficient grounds for further research, in my opinion.

 

[DC2]

Any posts by DVap or exogenesis are worth reading.

 

[AttyPops]

Sure it is. I hope testing continues as vaping progresses. That said, I used to burn chemical laden leaves in paper and inhale that. Not to detract from your point... however we have to remember that "It's gotta be better". Cigs contained VG BTW. Maybe PG too. And definitely nic and various flavorings. Not to mention a lot of other stuff.

Betting this thread is about to get moved to "safety" anyway....So Bookmark/subscript to it.

 

[DC2]

I don't think he is so much looking at safety issues here.

I think he is trying to understand how much nicotine we are inhaling.
And what happens to the rest if we are not inhaling all of it.

 

[Chriskarr]

You're exactly right, DC2. I want to figure out if we're all spending time developing mods and using products which just burn up all the precious juice we're working to deliver. After all, if we could get the same experience from a smaller amount of fluid, I imagine we'd all be happier for it. I don't know about any other modders out there, but I like to do enough research to make sure that my work is going to be top-notch.

For example, I'm currently working on a glass-coil interface which provides a seal to all but capillary action. I'm doing this in order to *attempt* to better moderate temperatures and have experienced a notable improvement in the quality of the vapor, even if the rate of juice-feed hasn't been perfected. Dang viscosity changes...

I'm not claiming to know anything more than anyone else here, I'm just trying to get everyone aware of a major issue and everyone who's concerned working to solve it. Personally, my KGO's atty gets red-hot when dripping after only one puff, unless it's so full of liquid that it leaks, and I find this to be unacceptable. I'd rather have something that's repairable and reliably going to remain that temperature. SS wick is the best around, but even with tanks it can dry out with certain vaping habits and certain liquid viscosity.

The potential issue being that we may be feeding so much energy into making our delicious liquid into a vapor that we destroy the wonderful little molecules we want most.

 

[greyv]

ten characters

 

[AttyPops]

Oh. I've had that discussion before. I don't know of a full study for that one yet. Good luck! (looks for door. zooms out).

 

[conflator]

Perhaps unsurprisingly, google brought me right back to ECF. These threads might be interesting:

A Somewhat Scientific Test of the electrial properties of different MODS

Propylene Glycol Vaporization/Atomizer Temp??

One thing I'm not quite getting is that the boiling point of PG (according to Wikipedia) is 188.2 °C (370.8 °F), and from what I found in those two threads, the atomizer seems to be hitting in the neighbourhood of 50 °C. Obviously there are other things in the juice, but I don't think it should make that much difference. Does PG not need to be heated to boiling to form vapour?

 

[conflator]

Should have read more before demonstrating my ignorance

MSD Sheet for PG at DOW

This lists the heat of evaporation (which I think is what we want?) at 25 °C (77 °F)

 

[Cloud Wizard]

I just looked for some references I had found a while ago and there was (as expected) a huge variation in temp produced by coils dry/wet (as someone posted earlier). I seem to remember dry coils hitting ~1300 and wet coils staying in the 300-500 range (temp checked with IR). I'll keep looking through old links and see if I can find it for you.

EDIT: found this: http://www.e-cigarette-forum.com/fo...pylene-glycol-vaporization-atomizer-temp.html - duh same you had posted

 

[Chriskarr]

Conflator, we don't want the heat at which it's able to evaporate. What we're looking for is the boiling point. It's to that temperature which we heat our liquid before it begins regulating the coil's temperature.

PG boils at 187.4ºC.
Nicotine boils at 247ºC.
Glycerol boils at 290ºC.

 

[conflator]

Chriskarr, what you say makes sense. I'm having trouble reconciling the temperatures reported in the above linked thread (especially the one where the temperature was measured directly via probe rather than infrared). Those don't seem near high enough to reach boiling.

Entirely possible I'm missing something obvious though - not exactly my area of expertise! Very interested in the answer to your question, though.