Boiling Points

[Caterpiller]

I've just done a little reading on PG and VG.

I was surprised to find that PG has a boiling point of 188c, and VG of 290c.

Considering the short distance between the coil and the end of the dip tip on most clearomisers, I'm struggling to understand where the vapour has a chance to cool down before being inhaled.

I'm no scientist and probably missing something here, but how can we be inhaling a vapour that is 200+ degrees c, without burning our mouths, throats and lungs?

 

[Izan]

Perhaps the same way we could inhale 500 degree cigarette smoke...

"Temperatures reach 900°C during a puff and fall to about 400°C between puffs (Guerin 1987). Puffing burns the tobacco on the periphery of the cigarette, and tobacco in the core burns between puffs (Johnson 1977; Hoffmann et al. 1979a).

You are correct.

Cheers


The science:

 

[Dave2603]

What Izan said..... plus, keep in mind that the vapor is being mixed with ambient air as you draw on it. You are therefore not inhaling the pure vapor from the coil, you re mixing it with cooler air as you draw on it.

 

[Spencer87]

We are not inhaling the boiling liquid. We are inhaling the steam that is produced from the liquid. This is in a constant state of cooling from the moment it comes off the coil and is mixed with the cool air.

 

[Ryedan]

I've just done a little reading on PG and VG.

I was surprised to find that PG has a boiling point of 188c, and VG of 290c.

Considering the short distance between the coil and the end of the dip tip on most clearomisers, I'm struggling to understand where the vapour has a chance to cool down before being inhaled.

I'm no scientist and probably missing something here, but how can we be inhaling a vapour that is 200+ degrees c, without burning our mouths, throats and lungs?

Izan made a very good point. Just wanted to add my opinion to that

The amount of VG/PG in our vape is nowhere near 100% of what we inhale or it would be a liquid and that would be really hot. In the process of atomizing juice a lot of air gets mixed in as we take a drag. Vapor droplets are really small and have very little heat energy in them, regardless of their temperature at the beginning of this process. That heat transfers really quickly to the air in the drag cooling the droplets quite fast.

I can say for a fact that I've vaped at quite high wattage and that did not burn me. I've also experienced some really burnt hits over the years and though they were inhales from hell, they did not actually burn me.

 

[Caterpiller]

So it's the air being pulled in through the air holes at room ambient tempurature that cools the vapour before reaching your mouth.

Got it.

Thanks.

 

[Spencer87]

So it's the air being pulled in through the air holes at room ambient tempurature that cools the vapour before reaching your mouth.

Got it.

Thanks.

That and the air already inside the RDA, All of it cools the vapor down, Any air...
Here. Think about this. Go boil a pot of water. Imagine putting your hand in to the water. your hand would start to cook, and would burn instantly. But putting your hand a few inches above the pot, while still being really hot, would not burn as instantly. now a foot above that pot, and while steam still touches your hand, its cooled to a point of warmth, not burning heat.
Now imagine that pot is 200 times smaller, as is your stove coil. because the size of the liquid is 200 times smaller, you can put your hand 200 times closer while still only getting the warmth, not getting burnt. I would suggest most people have between a centimeter to an inch in between the coil and the mouth, which is a lot comparitive to the size and amount of the liquid being vaped. More Steam only because it is a different type of liquid.

 

[Bunnykiller]

I thought steam had 540 calories per gram as compared to 100 calories for 1g of water at 100C

 

[sonicbomb]

Perhaps the same way we could inhale 500 degree cigarette smoke...

"Temperatures reach 900°C during a puff and fall to about 400°C between puffs (Guerin 1987). Puffing burns the tobacco on the periphery of the cigarette, and tobacco in the core burns between puffs (Johnson 1977; Hoffmann et al. 1979a).

You are correct.

Cheers


The science:

Thats a beautiful equation

sent from my G3 using Tapatalk

 

[rolygate]

The atomiser runs at around 70 degrees C in cigalike and ego-type heads. It goes higher in VV devices, and will go to around 200 C in hard-driven RBAs.

So there is no steam from basic devices. There's none even from high-power devices because there are so many factors that act to cool the vapour: water added to the PG/VG mix changes the boiling point, as does any ethanol (and there's usually some from flavourings); the size of the atomiser chamber (smaller = cooler), the air throughflow, the negative pressure, and more. The vapor point is too low for steam to be created.

One of the jobs that PG and glycerine do is to aerosolise water and make water vapour visible when it is way below boiling point. To be accurate it is a liquid aerosol, a suspension, not vapour (there is water vapour in there but you can't see it). There is a droplet size point where below it is invisible vapour and above it is aerosol.

The aerosols we inhale are liquid aerosols comprising a visible suspension of liquid particles ('droplets') plus invisible water vapour. Smoke is a visible suspension of solid particulates plus invisible pyrolytic gases. Liquid aerosols and solid particulate aerosols behave differently in the lungs: liquid droplets are absorbed fully and disperse, which is why breathing in the air above a kettle, in a sauna, below a waterfall or in a sea wave splash zone are of no consequence, whereas breathing in smoke has consequences due to the solid particulates.

When you see exhaled breath on an icy cold morning, it's not steam.

 

[hardadi]

Steam and vapour are two different thing. Steam produced when liquid boils. Vapour are substance in gaseus phase. Vapour can co-exist with liquid. That means even at temperature in which a liquid remains largely as liquid, vapourizing still could happen.
When you put a bowl of soup in your refrigerator for a long period of time, say one month, water in your soup will vaporize and disappear. Even at low temperature!

Temperature and pressure play important thing in vapourizing. In this vaping world, all that matter to us is vapour. We do not always have to put Glycerol to it's boiling point to make a decent vapor, i.e. vapourizing it. So, carefully set up your gear to do better vapourizing. Not making it as a steam boiler.