Is there a better atomizer design?

[jarvis]

Nomex and kevlar are both variations of heat resistant aromatic polyamide fibers, which is the thing that ludo said are in janty's atomizers so probably all the other ones as well. There hasn't been any kind of testing of this material in the application we are using it for. I found some data sheets from DOW chemical on these materials and they said:
" BURNING NOMEX & KEVLAR PRODUCE HAZARDOUS GASES SIMILAR
TO THOSE FROM WOOL; MOSTLY CARBON MONOXIDE, CARBON DIOXIDE, NITROGEN OXIDES
& SMALL AMOU NTS OF HYDROGEN CYANIDE, AMMONIA, ALDEHYDES, ALIPHTIC
HYDROCARBONS & OTHER TOXIC GASES DEPENDING ON BURN CONDITIONS."

So who knows how dangerous inhaling this stuff is in small amounts while the atomizer we are puffing on is gradually degrading. It'd be nice if a manufacturer would address this, but none will, as having a potentially harmful substance at the center of the thing they're selling as safe is not good for buisness.

 

[jigtg]

Nomex and kevlar are both variations of heat resistant aromatic polyamide fibers, which is the thing that ludo said are in janty's atomizers so probably all the other ones as well. There hasn't been any kind of testing of this material in the application we are using it for. I found some data sheets from DOW chemical on these materials and they said:
" BURNING NOMEX & KEVLAR PRODUCE HAZARDOUS GASES SIMILAR
TO THOSE FROM WOOL; MOSTLY CARBON MONOXIDE, CARBON DIOXIDE, NITROGEN OXIDES
& SMALL AMOU NTS OF HYDROGEN CYANIDE, AMMONIA, ALDEHYDES, ALIPHTIC
HYDROCARBONS & OTHER TOXIC GASES DEPENDING ON BURN CONDITIONS."

So who knows how dangerous inhaling this stuff is in small amounts while the atomizer we are puffing on is gradually degrading. It'd be nice if a manufacturer would address this, but none will, as having a potentially harmful substance at the center of the thing they're selling as safe is not good for buisness.

http://www.e-cigarette-forum.com/fo...-suppliers-whats-my-atomizer-3.html#post43348

All devices I've tested had silica judging by the fact that lighters ~1300C temperature didn't burn or cause any other visible damage. I also doubt there ever were "aromatic polyamide fibers" on janty atomizers. Shame that kate did not burn test it.
Fiberglass fibers are not pure silica unfortunately as I found out so finding silica can prove to be difficult.

 

[jarvis]

Then do you suppose that the repeated exposure to direct contact with heat caused them to char or perhaps the atomizer you tested has a better material inside it?

 

[Austintatious]

Here is my attempt. The sizes are not truly representative, only intention is to show design.

As you can see, air draws the liquid towards the atomizer which is a flat coil (like a car cig lighter) Current is provided from the battery through a metal "Filter housing" with inner and outer parts insulated from one another.

The Wick material rest on the atomizer bringing liquid to be vaporized by means of capillary action and assisted with the airflow and thus element stays wet. If the material Does burn it is easily replaced with new material.

Cons, If sufficient wick does not occur, there is no way to "drip" or put liquid directly onto the atomizer.

Pros, Provides much more area for capillary action to occur vs the traditional element setup

 

[Trumpybloke]

I am currently engaged in experimentation with nichrome and hightemp fibreglass silica wicking ( such as is used in heatseals in fireplaces) ......... looking promising ... There will surely be the naysayers about inhaling fibreglass, but as the wicking is wet with fluid there should be little if any loose fibre particles inhaled, I think you are experiencing greater exposure having ceiling batts and rodents lol !!!
I like your layout Austin , I might have to pinch it

 

[Austintatious]

Thanks. For some reason my post disappeared.

 

[jigtg]

I am currently engaged in experimentation with nichrome and hightemp fibreglass silica wicking ( such as is used in heatseals in fireplaces) ......... looking promising ... There will surely be the naysayers about inhaling fibreglass, but as the wicking is wet with fluid there should be little if any loose fibre particles inhaled, I think you are experiencing greater exposure having ceiling batts and rodents lol !!!
I like your layout Austin , I might have to pinch it

You probably want to burn test it with a lighter to see if it is really silica. Fibreglass I had fused together when heated. As far as I can see, there aren't many materials that can withstand 1650 celsius temperature and not conduct electricity... As far as inhaling silica goes, people have probably inhaled hefty doses of sand during sand storms and lived to tell the story. All forms of sand contain silica as far as I can tell. Fibers I've seen are not strong enough to cause any physical damage. Then again, people working at construction yards wearing inadequate protection handling glass wool have lived to tell the story. Glass wool particles penetrate skin causing akward tingling sensation as some of you might of noticed... Or actually, wiki/Silica says it is safe so I'm wasting my time here. "dust becomes lodged in the lungs and continuously irritates them" part does not really apply here as they are fibers and will remain as such. No way could you inhale enough fibers to cover your lungs and not notice fibers coming out of your lungs when you cough.

Yarns ? (KLEVERS - Glasgewebe) lists some materials.

 

[Trumpybloke]

Jigtg, I think a lot of the problems with source materials are simply we are looking for properties that aren't really necessary ?
I am not exactly sure of the real temps involved in practical vaping , but in theoretical vaping , the filament and wicking should energise just enough to produce a good vapour??
this would be in the 300 odd C mark and as such fibreglass should be more than adequate.
I could be totally wrong ( awaiting arrival of a IR thermometer for testing purposes) but I think actually "driving " the nichrome filament with a regulated Amperage might be the key for a long lasting design, we want to vaporise the fluid , not burn the crap out of it so it produces a cloud LOL supplying the correct amount of power to vaporise the liquid, but not degrade the materials used is the key I think....

 

[jigtg]

Jigtg, I think a lot of the problems with source materials are simply we are looking for properties that aren't really necessary ?
I am not exactly sure of the real temps involved in practical vaping , but in theoretical vaping , the filament and wicking should energise just enough to produce a good vapour??
this would be in the 300 odd C mark and as such fibreglass should be more than adequate.
I could be totally wrong ( awaiting arrival of a IR thermometer for testing purposes) but I think actually "driving " the nichrome filament with a regulated Amperage might be the key for a long lasting design, we want to vaporise the fluid , not burn the crap out of it so it produces a cloud LOL supplying the correct amount of power to vaporise the liquid, but not degrade the materials used is the key I think....

I do not really see what other properties could you possibly want.
It is unlikely you will be able to get a correct readout with IR thermometer since it probably relies on amount of IR radiation not intensity. Reaouts with thermocouple[1] I got on my mini were around 400-450 celsius. Agreed, I was pushing it to the limit but that's the readout I got. Someone also compaired the color of wire and said something like 350-400 celsius.
As long as the fiberglass does not burn(non of the fibers get cut) in any way and doesn't dissolve in e-liquid, it should be ok. You could heat some fibers for couple of hours and see if it survives...
There will always be slight impurities and flavors that cannot take the heat so you cannot completely eliminate the problem without using ultrasonics or something. Lowering temperature will lower burning and vapor production. If you want to lower temperature, you need to increase surface area made in contact with e-liquid to make enough vapor. Unfortunatelly, lowering temperature, say 50 celsius, might mean you need to increase surface area 4 times to produce same amount of vapor. See File:Water vapor pressure graph.jpg - Wikipedia, the free encyclopedia to get the idea.

[1] See http://www.e-cigarette-forum.com/fo...tine-calculation-juice-mixer-3.html#post29079 if interested. That specific thermocouple is rated 250 celsius max but you can push it way beyond that if you don't mind insulation melting. I don't use cold water anymore but assume 21 celsius room temperature - give or take, resolution is "only" +-5 celsius. Pressing strand ends against nichrome wire should give you fairly accurate readings though there are things such as thermocouple wire conducting heat and contact not being perfect to consider. Great toys to say the least.

 

[Lithium1330]

What we do need for the wick? well, it needs to have capilarity, it must to be not electrical conductive, and it needs to be heat resistant, lets make a list of material, my fovorite candidate is porous ceramic, it has capilarity, it is heat resistant and it is not conductive.

Also a good design could be take off the metalic mesh, its only function is to make a permanent contact between the liquid and the coil, the liquid pass from the mesh to the coil by capilarity and wets the wick, lets say we put the coil vertically, then we make a deposit for the liquid upside the device (cart) with a porous ceramic stick attatched down the deposit, the stick will fit inside the vertical coil and then the liquid will flow from the deposit through the coil directly, the deposit could be filled with a lot more liquid and the size of the atomizer could be reduced dramaticly due to this way we don't need room for the mesh.

 

[Trumpybloke]

Porous ceramic sounds great , but I am a little worried about it blocking over time, all liquids will have some sedimentary matter in them unless they are of laboratory purity ?? There is also the matter of heat,vapour, blocked pores,expansion, and explosive ( minor I am sure ) deconstruction if liquid is trapped in a pocket ( that's being very alarmist I know )
Actually the further I delve into it , the more I am convinced a method of dropping straight liquid into a carefully designed conical nichrome coil where it can flash vaporise might be the go ? no wicks , nothing to get clogged, just a drip and PHWOOF !! lol

 

[Lithium1330]

But there is alredy a ceramic pieace in the atomizers maybe it dosnt need to be porous, just regular ceramic just to transfer liquid from the deposit to the coil via capilarity, whatever we use, it must be something easily replaceable, so when it gets a little burned we can just put a new wick on it, if we use a wick a good idea is to make this wick external and coupled with the coil just when it is going to be used.

 

[Vageorge]

Ceramic Wick
www DOT hung-hsin DOT com DOT tw/images/E_B10 DOT htm

Flexible foil heating element
www DOT minco DOT com/

 

[Vageorge]

I should add that these are purpose built ceramic wicks, 4mm diameter if i remember correctly. Just wrap the wire around it and away you go.

 

[kinabaloo]

Trumpy - perhaps best way to do what you suggest is with a simple zozzle to fire a mist towards an open coil, perhaps by some kind of mini electrical pump. Or the mist could be created by a miniature piezo transducer as you find in some battery operated air fresheners that periodically fire out a mist. Some kind of hot plate rather than coil would be more robust and long-lasting - perhaps ceramic or graphite.

Vageorge - have you tried this out (ceramic wick as atomiser coil core) ?

 

[Lithium1330]

Ceramic Wick
www DOT hung-hsin DOT com DOT tw/images/E_B10 DOT htm

Flexible foil heating element
www DOT minco DOT com/

Ohh! this is exactly what we need, look at the flexible heaters!

A round heater with a ceramic wick in it might do the job!

Thanks Vageorge

Ceramic Wick:

Ceramic Wick for Liquid Mosquito Repellent & Essential Oil

Flexible Heaters:

Minco - Flexible Heaters; Flex Circuits; Temperature Sensors and Temperature Instruments

 

[Toby]

I personally think there ought to be some more development in better functioning wadding in the carts...

 

[Vageorge]

Sealed refillable fluid cartridge with wick protruding into fluid. Wick is porous ceramic tube. The heating coil is inside the ceramic wick and heats the inside wall releasing vapour which is sucked up the top and out the bottom. A filter membrane sits on top of ceramic/element to only allow gases to pass through, preventing unvaporised fluid from getting into mouth. Damaged coils easily slip out for replacement.

 

[katink]

Is that one of those flexible heaters in there Vageorge?
Wow, you might be on to a great way to build the e-cigs ourselves, including atomizers! I will be very interested indeed to see you actualy build this and telling us how it goes.

 

[Vince1]

That looks like it has potential Vageorge. I like the fluid resoviour from the picture but can't get the links to work for some reason.

Edit- nevermind.... THANKS Lithium!