Wire/coil gauge efficiency testing
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Have you calculated the surface area of the radiator coils vs thicker wire coils? Define surface area. Total wire surface area or wick contact area?
It is true that if you radiate 100J of heat off a 1cm^2 surface vs 2cm^2 surface, that the smaller surface will reach a higher temperature. He gets it
However, the boiling point of your juice will limit the temperature the surface reaches, provided the surface does not run dry. There are some limitations to this, as a yellow hot piece of steel quenched in water will not cool to 100C instantly, but that involves very large amounts of heat transfer and massive amounts of vapour production. It is unlikely that your coil will exceed the BP temp of your juice unless you're working for a stage production. I doubt it would do this during normal operation with a well-wet wick.
The "wind shadow" you refer to is not a term I am familiar with but you seem to mean the region of eddgy currents that form on the other side of an object in a fluid stream where the flow regime (eg reynolds number) is turbulent. This wind shadow scales with object size and flow regime but again I dont think its going to make enough of a difference to be worth researching. The coil in that dead zone over heats because of lack of air flow cooling.
Glycerol is not a sugar. By the same logic, methanol is a sugar because it contains hydroxy groups and the same could be said for ethylene glycol. If the juices contained sugar, your coil and wick would fowl up within minutes with caramel and char. Decomposition and fouling are a function of juice flow from the wick to the coil surface, duration of each vape, temperature of the coil and VG content (and flavours to a lesser extent). Fluids higher in VG will produce thicker clouds, but as VG content exceeds 70% the boiling point gets closer to 290C, where large amounts of decomposition of the VG will occur. It's not the pg or vg that gunks coils but the flavorings and sweeteners.
The oxide layer on the coil wont significantly effect heat transfer unless it is very thick and visible, like the oxide layer on a dry fired Ti coil. It may however react with the juice (e.g. nickel oxide on nickel coils combined with a tart/sour juice), it will significantly increase the porosity of the coil surface.
Lets use another example. Spongebob is lying on a hot element, face down. Water close to the surface of his back being heated will vapourize and create a local pressure increase. Water will continue to evaporate at a rate that cannot be replaced by simple capillary action through the sponge. Eventually spongebob will burn, even if water is applied to the side facing up. Poor spongebob.
Drier regions will begin to heat up above the juice BP as they dry out thus facilitating greater decomposition of juice.
The reason your juice is going brown and your coil is fouling is because of high temperatures decomposing the juice. Decomposition products of e-juice are primarily formed from flavouring esters and glycerin as PG boils well below its decomposition point. The hotter you run your coils and the more immediate the vapour production, the more decomposition will be occuring, producing yummy goodies like formaldehyde, acetaldehyde, dihydroxyacetone and a number of other components. Again it's the flavorings and sweeteners.
The resistance is relevant. If you want to compare the efficiency of using different coils, you need to have coils with similar resistances and wetted surface area. Yes, they will all run the same power (W) but a coil with half the surface area of another will deplete juice in contact with the coil more rapidly. This effectively imposes a greater mass transfer limit for juice to move through the wick and to the coil. You could have 1 wire the same length as 2 smaller wires with the same collective surface area and see how that performs. Im sure it will perform better, like claptons do. Resistance is not relevant. I'm comparing contact coils of the same inner circumference and width run at the same wattage.
However, your radiator coils, while having greater surface area, are not without drawbacks. As mentioned before, same with claptons, tighter nooks and crannies on your coils will produce more hot spots and possibly lead to significantly more juice decomposition and fouling. On the other hand, provided the wick is kept well wet and you arent overpowering the coil, the additional nooks and crannies will retain more fluid and improve the capillary action.
@MacTechVpr This one is all yours
Depending on the type of metal on the coil, hydroxides may form in addition to oxides. These hydroxy groups on the surface will form hydrogen bonds with the Pg and VG in the e-juice and improve wetting of the coil. If you want to test this knock yourself out.
It is true that if you radiate 100J of heat off a 1cm^2 surface vs 2cm^2 surface, that the smaller surface will reach a higher temperature. He gets it
However, the boiling point of your juice will limit the temperature the surface reaches, provided the surface does not run dry. There are some limitations to this, as a yellow hot piece of steel quenched in water will not cool to 100C instantly, but that involves very large amounts of heat transfer and massive amounts of vapour production. It is unlikely that your coil will exceed the BP temp of your juice unless you're working for a stage production. I doubt it would do this during normal operation with a well-wet wick.
The "wind shadow" you refer to is not a term I am familiar with but you seem to mean the region of eddgy currents that form on the other side of an object in a fluid stream where the flow regime (eg reynolds number) is turbulent. This wind shadow scales with object size and flow regime but again I dont think its going to make enough of a difference to be worth researching. The coil in that dead zone over heats because of lack of air flow cooling.
Glycerol is not a sugar. By the same logic, methanol is a sugar because it contains hydroxy groups and the same could be said for ethylene glycol. If the juices contained sugar, your coil and wick would fowl up within minutes with caramel and char. Decomposition and fouling are a function of juice flow from the wick to the coil surface, duration of each vape, temperature of the coil and VG content (and flavours to a lesser extent). Fluids higher in VG will produce thicker clouds, but as VG content exceeds 70% the boiling point gets closer to 290C, where large amounts of decomposition of the VG will occur. It's not the pg or vg that gunks coils but the flavorings and sweeteners.
The oxide layer on the coil wont significantly effect heat transfer unless it is very thick and visible, like the oxide layer on a dry fired Ti coil. It may however react with the juice (e.g. nickel oxide on nickel coils combined with a tart/sour juice), it will significantly increase the porosity of the coil surface.
Lets use another example. Spongebob is lying on a hot element, face down. Water close to the surface of his back being heated will vapourize and create a local pressure increase. Water will continue to evaporate at a rate that cannot be replaced by simple capillary action through the sponge. Eventually spongebob will burn, even if water is applied to the side facing up. Poor spongebob.
Drier regions will begin to heat up above the juice BP as they dry out thus facilitating greater decomposition of juice.
The reason your juice is going brown and your coil is fouling is because of high temperatures decomposing the juice. Decomposition products of e-juice are primarily formed from flavouring esters and glycerin as PG boils well below its decomposition point. The hotter you run your coils and the more immediate the vapour production, the more decomposition will be occuring, producing yummy goodies like formaldehyde, acetaldehyde, dihydroxyacetone and a number of other components. Again it's the flavorings and sweeteners.
The resistance is relevant. If you want to compare the efficiency of using different coils, you need to have coils with similar resistances and wetted surface area. Yes, they will all run the same power (W) but a coil with half the surface area of another will deplete juice in contact with the coil more rapidly. This effectively imposes a greater mass transfer limit for juice to move through the wick and to the coil. You could have 1 wire the same length as 2 smaller wires with the same collective surface area and see how that performs. Im sure it will perform better, like claptons do. Resistance is not relevant. I'm comparing contact coils of the same inner circumference and width run at the same wattage.
However, your radiator coils, while having greater surface area, are not without drawbacks. As mentioned before, same with claptons, tighter nooks and crannies on your coils will produce more hot spots and possibly lead to significantly more juice decomposition and fouling. On the other hand, provided the wick is kept well wet and you arent overpowering the coil, the additional nooks and crannies will retain more fluid and improve the capillary action.
@MacTechVpr This one is all yours
Depending on the type of metal on the coil, hydroxides may form in addition to oxides. These hydroxy groups on the surface will form hydrogen bonds with the Pg and VG in the e-juice and improve wetting of the coil. If you want to test this knock yourself out.
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But amusing.
My work here is done. Waiting to see that PhD thesis you wrote Boden
btw, the electromagnetic field generated by the electric flux travelling through your groundbreaking radiator coil is going to give you cancer.
Plus, the hexavalent chromium forming on your coils will leech into your juice and cause oral/oesophageal cancer. Only for you though Boden
but you already know this, right
**This post is satire**
btw, the electromagnetic field generated by the electric flux travelling through your groundbreaking radiator coil is going to give you cancer.
Plus, the hexavalent chromium forming on your coils will leech into your juice and cause oral/oesophageal cancer. Only for you though Boden
but you already know this, right
**This post is satire**
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Of course. Did you take into account any of the aforementioned fluxes? I thought not.
Inquisition : 1
Oliver Cromwell : 0
Inquisition : 1
Oliver Cromwell : 0
oliver cromwell. Did he have a son? Maybe a robert? im not sure. I guess I dont care
capacitance flux doesnt exist because a flux implies movement. Once capacitance builds between two surfaces, it doesnt "move" unless the circuit is broken. Hence the word "influx"
A diffusive flux, like acetone vapour coming from an open bottle, is a constant flow until all the acetone is gone.
You might want to check out capacitive flux density sensors.
If you don't care why the Oliver?
If you don't care why the Oliver?
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I know who oliver cromwell is but i dont know why your name is robert when it looks like oliver
The sensors are capactive. They measure flux density. Not capacitive flux. Your earlier response was better but you deleted it. Ill give you half a point, cromwell. But the royalists are not so easily defeated.
The sensors are capactive. They measure flux density. Not capacitive flux. Your earlier response was better but you deleted it. Ill give you half a point, cromwell. But the royalists are not so easily defeated.
Ohh you mean that capacitors have leakage and therefore flux?
Was just trying to make a flux capacitor
Ohh and Robert Cromwell:
Robert Cromwell, "Baron Cromwell of Carleton" (c.1390 - 1461) - Genealogy
Was just trying to make a flux capacitor
Ohh and Robert Cromwell:
Robert Cromwell, "Baron Cromwell of Carleton" (c.1390 - 1461) - Genealogy
Your name must be robert, because ive never heard of this guy. Im not the only one, google seems pretty indifferent too
Hey look i found that silly smiley bog was using
They have a flux of charge, not capacitance. I actually got my definition of flux wrong, but that doesnt validate your argument unfortunately
Here is the wiki page. Can you find capacitive flux for me
Even a scientific paper talking about it would be fine. I am genuinely interested. No really I am
My definition of flux was for mass transfer, not for electromagnetic flux. Your capacitance field is not moving anywhere. It is getting smaller though as it leaks.
Inquisitor Templar : 1
Robert Baratheon : 0.5
Hey look i found that silly smiley bog was using
They have a flux of charge, not capacitance. I actually got my definition of flux wrong, but that doesnt validate your argument unfortunately
Here is the wiki page. Can you find capacitive flux for me
Even a scientific paper talking about it would be fine. I am genuinely interested. No really I am
My definition of flux was for mass transfer, not for electromagnetic flux. Your capacitance field is not moving anywhere. It is getting smaller though as it leaks.
Inquisitor Templar : 1
Robert Baratheon : 0.5
Your taste in jokes needs work. Somebody less educated might read this and think you are serious. Fear mongers love this kind of stuff.
I have 8oz of 24 gauge SS316L, low carbon content and high resistance to carbide formation at the crystalline grain boundary means its great for building resistance heating coils. Would you like me to send you some boden?
Theres a sheet below talking about the differences of 316L vs standard 316. Its in the carbon content. Since we arent making stainless steel blades, its best to go for a stainless steel with low carbon content. More carbon means a harder, but more brittle steel which will succumb to creep and mechanical attrition faster when used for e-cig coils.
http://www.aksteel.com/pdf/markets_products/stainless/austenitic/316_316l_data_sheet.pdf
PS are you thinking of doing 24 gauge radiators? That will be super sub ohm I think
Theres a sheet below talking about the differences of 316L vs standard 316. Its in the carbon content. Since we arent making stainless steel blades, its best to go for a stainless steel with low carbon content. More carbon means a harder, but more brittle steel which will succumb to creep and mechanical attrition faster when used for e-cig coils.
http://www.aksteel.com/pdf/markets_products/stainless/austenitic/316_316l_data_sheet.pdf
PS are you thinking of doing 24 gauge radiators? That will be super sub ohm I think
Thank you but I have some on the way. I've been working with SS for a long time in my businesses. Suffice to say I'm quite fimilar with it. My fabrication experience and the safety protocols in my shop are the reason I spent all that money to have several grades of SS mesh in eliquid lab tested for Hexavalent Chromium contamination all those years ago. Money well spent I'd say.
I'm mostly retired now but prototype doohickeys and one off race engine parts was our main focus, that's how I learned about ceramics. Now I mostly design speakers for the stupid rich. Home theater installations that make a IMAX sound system seem tame. Is fun though.
A 17/16 wrap 4mm single wire 24ga 316L coil comes out to 0.77 ohms. Two in parallel comes out to 0.385 ohms. Not quite super sub-ohm.
I don't know if I'll make them round or oval.
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