Hi, I’m making a very small smoke generator and I’ll be using a 5v 3010 Turbine Blower Fan on its own power supply. I intend to use 2x 1.2v 2200mah 4/5 sub C batteries and 0.2mm nichrome wire. To create smoke using cotton soaked in a mixture of 50% Vegetable Glycerine and 50% distilled water I need to heat the wire to around 50c. My question is what length wire do I need?
As always any help is very much appreciated.
Regards Peter

 

I need to heat the wire to around 50c.

That's only hand hot. Seems far too low for smoke generation.
Without knowing what/how much material contacts the heating element, the thermal coupling efficiency, the element shape (coiled or straight?) and ambient conditions (temperature/insulation) it's impossible to say what wire length you'll need. You'll just have to experiment.

 

That's only hand hot. Seems far too low for smoke generation.
Without knowing what/how much material contacts the heating element, the thermal coupling efficiency, the element shape (coiled or straight?) and ambient conditions (temperature/insulation) it's impossible to say what wire length you'll need. You'll just have to experiment.

Hi Alec, thank you for your interest. Yes, I was expecting to have to experiment but hoped I might get a bit of an idea or the equation to some calculations.
I was working on 50c as I read this: Glycerine smokes at about 50-60°C - on a very informative website here:https://www.smokemachines.net/concept-smoke-fluid.shtml
Peter

 

That's only hand hot. Seems far too low for smoke generation.
Without knowing what/how much material contacts the heating element, the thermal coupling efficiency, the element shape (coiled or straight?) and ambient conditions (temperature/insulation) it's impossible to say what wire length you'll need. You'll just have to experiment.

Hi Alec, thank you for your interest. Yes, I was expecting to have to experiment but hoped I might get a bit of an ide or the equation to some calculations.
I was working on 50c as I read this:Glycol smokes begin to layer noticeably at 35-45°C, Glycerine smokes at about 50-60°C on a very informative website here:

 

From what I read in that link ("Artificial smoke is produced by heating a chemical above its boiling point within a heat exchanger.") I think the 50-60C refers to the temperature glycerine vapour has to cool down to before it becomes visible as a fog. N.b the boiling point of glycerine is 290C.

Edit:
Found a description of an e-cig which says "The e-liquid reaches a temperature of roughly 100–250 °C (212–482 °F) within a chamber to create an aerosolized vapor."

 

From what I read in that link ("Artificial smoke is produced by heating a chemical above its boiling point within a heat exchanger.") I think the 50-60C refers to the temperature glycerine vapour has to cool down to before it becomes visible as a fog. N.b the boiling point of glycerine is 290C.

Edit:
Found a description of an e-cig which says "The e-liquid reaches a temperature of roughly 100–250 °C (212–482 °F) within a chamber to create an aerosolized vapor."

Thank you Alec, sorry I didn’t read it properly. Yes I’ve tried to use information on vaping to get a better understanding on producing smoke. I’ll go back to experimenting, I think starting with a slightly longer wire and shorten until I start getting results.
Peter

 

Thank you Alec, sorry I didn’t read it properly. Yes I’ve tried to use information on vaping to get a better understanding on producing smoke. I’ll go back to experimenting, I think starting with a slightly longer wire and shorten until I start getting results.
Peter

In a nutshell a wire will be able to get hot enough for your purposes if it is thick enough. Think of the wires on a stove top or in a toaster.

Provided you follow safe chemistry practices and knowing what I know about your formula from your description, you could simply buy a portable stove top and drop some of your solution on it. Since these tops can boil water, we know that the surface reaches at least 100C. More heat will accelerate the evaporation reaction. Ideally you'll just get a lot of smoke if your solution is pure.

Make sure your not making a bomb or toxic molecules and be responsible with disposal. Also note that many "legal" chemicals related to this project and vaping are actually highly reactive and harm wildlife.

 

You need to know the resistance of the wire and calculate the total power from the formula Power (P) = I² * R.

 

In a nutshell a wire will be able to get hot enough for your purposes if it is thick enough. Think of the wires on a stove top or in a toaster.

Provided you follow safe chemistry practices and knowing what I know about your formula from your description, you could simply buy a portable stove top and drop some of your solution on it. Since these tops can boil water, we know that the surface reaches at least 100C. More heat will accelerate the evaporation reaction. Ideally you'll just get a lot of smoke if your solution is pure.

Make sure your not making a bomb or toxic molecules and be responsible with disposal. Also note that many "legal" chemicals related to this project and vaping are actually highly reactive and harm wildlife.

Very good and useful points, my project has no health or other danger as the only liquids being used are Vegetable Glycerine and water and they won’t be inhaled.
Peter

You need to know the resistance of the wire and calculate the total power from the formula Power (P) = I² * R.

thank you, Peter

 

Thank you all for your comments.
The good news is that nobody's said it wont work!
Peter.

 

Thank you all for your comments.
The good news is that nobody's said it wont work!
Peter.

The wiki page for vegetable glycerin (Glycerol) says it boils at 290C which is a big step up from your planned 50C. You said you wanted to know how long the wire would have to be in order to reach this temperature. The answer is it depends how much current is being passed though the wire over time to achieve your desired temperature.

Remember atoms change state when they reach a certain energy threshold. For the conducting wire doing the boiling, this is directly proportional to the current passing through it. In order then to determine the specifics of the wire to make sure it gets hot enough without melting, we need to know what the power supply is doing. Any power supply capable of delivering a high current at a low voltage should theoretically boil your liquid but it wont be efficient and you may generate byproducts. Have fun and be safe.

 

The wiki page for vegetable glycerin (Glycerol) says it boils at 290C which is a big step up from your planned 50C. You said you wanted to know how long the wire would have to be in order to reach this temperature. The answer is it depends how much current is being passed though the wire over time to achieve your desired temperature.

Remember atoms change state when they reach a certain energy threshold. For the conducting wire doing the boiling, this is directly proportional to the current passing through it. In order then to determine the specifics of the wire to make sure it gets hot enough without melting, we need to know what the power supply is doing. Any power supply capable of delivering a high current at a low voltage should theoretically boil your liquid but it wont be efficient and you may generate byproducts. Have fun and be safe.

Than you, lots of experimenting to be done!

 

a little late to the party, and I don't know how much this helps, but I found this link
https://simplyfog.com/wp-content/uploads/2018/05/Glycols-vs-Glycerin-Fog-Fluids.pdf
That says fog machines work between 310f(154c) and 450f(232c) (380f(midpoint) is about 193c).

If you've created anything and come up with some actual numbers, please let us know

 

Casual, yesterday I stumbled on a video (I did not open) to make a smoke machine to test automotive vacuum leaks. Not steam; not fog, not other but somehow, smoke. For sure youtube has material on it.

 

a little late to the party, and I don't know how much this helps, but I found this link
https://simplyfog.com/wp-content/uploads/2018/05/Glycols-vs-Glycerin-Fog-Fluids.pdf
That says fog machines work between 310f(154c) and 450f(232c) (380f(midpoint) is about 193c).

If you've created anything and come up with some actual numbers, please let us know

Thank you for the information.
I’m still working on the design, other parts of my project have taken precedent, but about to start. I'll now be working with 7.4v and better amperage, possibly using a vaping coil.
I’ll report on my progress.
Peter