That darn burning taste

[jdrancor]

So we've been talking about the burning taste for awhile.

I'm currently smoking a rn4081 or Super Cigarette, but this burning taste has eventually led me to ditch every atomizer, whether I use it exclusively with a cartridge or I exclusively drip. I've got 6 atomizers, 2 pen-style and 4 rn4081's that produce smoke, but along with it, they produce a NASTY burning taste. My short term solution is to buy a bunch of rn4081 atomizers (if you look around, you can get them for $7 a pop) and just replace them when they start tasting burnt. No amount of cleaning will get rid of the nasty burnt taste.

SO then. Why the burnt taste? As Jarvis has explained and diagrammed for us here in this post, there is a wick inside the filament that soaks up the liquid, which is then heated to create the vapor.

Here's a crude diagram:

This wick starts to burn after awhile, presumably because it dries out. And, from my experience, it dries out fairly easily. No amount of coddling seems to save it from drying out and tasting terrible in a week or two.

Additionally, there is the problem of the e-liquid itself leaving a residue behind. Perhaps this is also accountable for the taste: the liquid gets left behind, heats, burns, eventually it is a solid that is burning and that also could create a nasty taste. Here is a demonstration of the solids left behind (translated from Dutch)

So, what are the solutions? Well, I think, because of the solids left behind, that it is necessary to have a disposable atomizer. If there were no solids, or a dependable way of removing solids, we could have a permanent atomizer, but as there is no liquid that doesn't leave one solid or another behind, then we are best served going with a disposable atomizer.

There are two disposable atomizers on the market today. The LoongTotem and the GreenCig. I have read no reviews of the GreenCig, but the LoongTotem reviews have been negative, across the board. It has some sort of paper in the cart that burns and creates a bad taste. (I searched for the image, but couldn't find it. Can somebody help me out here?) So, there are no good disposables out right now.

Here's what I'm coming to. How about a longer thicker wick that goes into a cartridge that is FULL of nicotine liquid. This instead of the absorbent wool that is currently used to suspend the liquid. The cart would last longer, and the wick would remain wet constantly. By the time the solids from the liquid start to accumulate on the filament, the cart would be empty, and we could put in a fresh one. Here's another crude illustration:

Anyhow. It's a thought. Aside from convenience, I think that, because of the inevitable solid accumulation on the atomizer, that a disposable cart will be the only way to go.

 

[CaSHMeRe]

Drawings are great ... LOL ... some massive paint skills going on there.

Good idea though. So many good ideas, just no funds behind them to back them up and get them produced. hmmm....

 

[RatInDaHat]

man either you have a tablet, or your mouse skills are better than mine.

 

[TropicalBob]

Looks ingenious to me. You eliminate the "roll cage" over the heater element, assure a more consistent flow of fluid, and -- important to me -- get rid of the core material (polyester in some cases) that ends up as stray fibers in your atomizer or, worse, burned areas in your cartridge. Not sure why someone hasn't tried your idea. And it shouldn't be more expensive than the present setup, unlike making an ultrasonic mister, for instance.

Zippo lighter = inspiration.

 

[RatInDaHat]

hell, if someone makes a good ultrasonic one, i'd pay the price.

With that being said, i would have no problem with disposable ones either.

 

[jarvis]

Yes I like these ideas. Here's a sloppy manip of an earlier cross section I posted of a possible solution to the burning fiber. Incorporate a new coil/fiber, the steel wool bridge, and a bit of the ceramic into the cartridges. Would save a bit more material than the whole atomizer being thrown out.

 

[MNZ]

Let's consider for a moment what the atomiser does and the way it does it.

The device consists of a pot made of metal, ceramic, or a combination of those materials. In the centre of the pot is a heating coil with a material core centre. Surrounding the pot is a basket of steel wool. Rising above the pot is a bridge made of steel wool.

So that is the basic mechanical design, next what happens when we "smoke" it.

Before I talk about how the device works it's a good idea to talk a bit about what each of the core components function is.

Steel wool bridge.
The bridge directly contacts the wool in the cartridge and by capillary action wicks the juice into the wool basket that surrounds the core pot.

Steel wool pot
This performs two functions,
i) it acts as the storage reservoir holding an amount of juice for use
ii) it performs the first stage of the atomisation process, more details below.

Heating coil
When heated to the correct temperature the coil creates mist from the droplets of PG and nicotine.

Heating coil wick
The wick seems to perform two actions,
i) it absorbs an amount of juice to provide it with direct contact to the heater coil
ii) providing thermal shock protection and heat caused deformation protection to the coil as it rapidly heats and cools.

Now we understand what each of the parts is doing, lets describe what happens

When we inhale on the device, the airflow is detected and the electronics kick in and connect the power from the battery to the heater coil and the timer circuit, after there has a continuous air flow of 3-5 seconds the timer circuit cuts the power to the heater coil.

When we inhale the liquid held in the wool basket is drawn into the central core of the atomiser in fine droplets, it's these fine droplets as well as the small amount of liquid held in suspension in the heater coil wick core that is turned into the vapour we inhale into our lungs.

The amount of mist produced is reliant on a number of factors
a. the amount of juice held in the basket
b. the amount of fine droplets created by inhalation
c. the surface area of the heater coil
d. the internal airflow design funnelling the droplets correctly onto the heater coil

From this it would seem logical to assume that provided sufficient juice is available in the wool basket that a smaller sized atomiser will produce greater smoke volumes than a larger device. Think of water flowing through a pipe, a large pipe gives a slower flow, a small pipe gives a faster flow. This is rather borne out by the reviews we have all seen of cigar sized unit and the much smaller DSE901 based devices, the smaller DSE901 wins hands down. This is purely due to the volume of air being drawn through a smaller surface area of mesh at higher velocity than the larger device and being able to draw more fine droplets onto the heating coil. The viscosity of the juice is an important consideration here, too thick and it wont form the initial fine droplets as it is sucked from the wool basket, too thin and it will not be held in the wool basket, but instead flow through it.

I'm only assuming the wick in the centre of the heating coil performs the actions I've attributed to it, it would seem to be the most reasonable suggestions for it's existence.

Is this what we can taste as a burnt taste in some atomisers ?
Yes I believe it is one of the providers of the burnt taste and quite probably the largest contributor. I think there are two other contributors.
The first is stray fibres from the cartridge coming into contact with the heater coil, note that it will need to be in contact with the coil directly not merely the wool bridge wick, although this will become heated it's large surface area will rapidly dissipate the heat away.

The second is evaporated juice burning off the surfaces of the atomiser. Think of the oven in your stove at home, cooking in the oven causes the walls of the oven to become dirty, this is from spatter or the condensing of vapours from the cooking. If the dirt is allowed to build up, eventually it begins to burn each time we use the oven, this is usually obvious by the amount of smoke that is produced, clean the oven and the smoke goes away. On a much smaller scale the same thing is happening inside our atomisers. It may also be happening on the wick in the centre of the coil, that would account of the blackened lumps we have seen in pictures. So regular cleaning to dissolve and remove crystallised or dried up juice residue is vital.

Would a different heater coil design help ?
Perhaps.
The coil of relatively fine wire is a highly effective method of producing the highest surface area of a material given a specific volume of material available. I do feel the linear shape of the coil is not the best configuration and that a circular or preferably a spiral shape may prove to be a better design to use.

I have also given some considerable thought to different shapes and materials, for example, a ceramic heater platform in a variety of different shapes, cubic, thin square, orb, ring, multi-faceted, etc but I continue to come back to the coil of wire as the most reasonably efficient method.

That will do for my ramblings so far, I hope this gives you something to think about and consider and offers up a view of what's going on inside your little device.

BTW, how the hell they can charge what they do for them is beyond me, they is nothing complex about the design, there are no exotic materials in the build, even the finish on them is really nothing out of the ordinary ... If the build cost including packaging in China was much more than US$1.00 I'd be surprised.

 

[jdrancor]

I like Jarvis's idea. I don't really see the necessity of having the steel wool bridge, however. I've been straight dripping, and I'm not trying for any degree of accuracy. So, plenty of my drips get into the ceramic pot, and directly on the coil itself, saturating the wick. I've found that when I put too much juice in, it doesn't smoke. So then I tip the cig upwards to let the juice run away from the coil, draw, and get smoke. So, I'm imagining that it would function fine if I dripped without the bridge - the only thing here is that the bridge absorbs a little liquid and keeps me from having to drip so often.

So I'm proposing that the primary function of the bridge is not to draw liquid but to keep the cartridge wool away from direct contact with the coil. Only this and nothing (not much) more. It's secondary function is just as MNZ says - it serves as a conveyance for the liquid from the cartridge down to the level of the filament. In fact, I just confirmed this - I pulled a bridge out of one of my nasty tasting atomizers, and it still produces smoke when I drip on it (still tastes nasty.) All that's missing is a reliable conveyance.

Anyhow, here's an iteration on MNZ's idea, sans wire bridge and with a redesigned battery that works more like an audio jack or a pen cap. My concern with this is that the liquid would wick too fast and be used up too quickly, but this could be remedied with the wick material, I suppose. Also, I like MNZ's idea of a spiral-shaped coil, rather than the current linear design. AND, I feel like the wick and coil would see the most action closest to the liquid reservoir, and I don't have an answer for this at the moment.

 

[jarvis]

Looks good jdrancor, with your wick design you could get rid of the steel wool bridge altogether, and perhaps even the ceramic reservoir part.

BTW, how the hell they can charge what they do for them is beyond me, they is nothing complex about the design, there are no exotic materials in the build, even the finish on them is really nothing out of the ordinary ... If the build cost including packaging in China was much more than US$1.00 I'd be surprised.

I've been wondering the same thing. I guess if they had stuck to the original patent design it could've been the advanced electrical device that they still claim it to be. for example:

(high frequency generator arranged on a control circuit board and used for generating a high frequency signal, nicotine solution storage container for storing nicotine solution, a control circuit further comprising a plurality of inputs and outputs arranged on the control circuit board and used for controlling the operation of the non-smokable electronic spray cigarette, an airflow sensor, a body sensitive sensor, an atomizer for atomizing the nicotine solution, a high temperature vaporization nozzle, wherein the vaporization nozzle is arranged in an air suction end of the shell and is coupled to the nicotine solution storage container, the nicotine storage container further comprising a liquid injection valve wherein the liquid injection valve is coupled to an electronic pump or a valve connected with a metering cavity, the atomizer is coupled to the high frequency generator, the plurality of outputs of the control circuit are coupled to the high frequency generator, an electric heater, and the electronic pump or valve respectively, the body sensitive sensor and the airflow sensor are coupled to inputs of the control circuit.)

But the companies cranking these things out have misleadingly retained some of the terms to make the devices sound expensive, and some people charge 100 bucks for something that is about as primitive as electrical devices get. I think people are wising up though, and I am seeing less and less websites attempting to resell these 30 dollar e-cigs for 70-90 dollars.

p.s. Are there any models that actually have the high frequency generators and vaporization nozzle/pump setup? I thought maybe the original ruyan and that's why it cost 180 bucks, but it's probably just like the low tech ones.

 

[MNZ]

jarvis,

Yes I'm afraid the ruyan products are the same as everyone else's all your paying for there is the name.

And I couldn't agree with you more ... If we were buying the device described in the original patent documents we certainly wouldn't be having this conversation now. The described beast is about as far removed from what's available as a Formula One car is to a lawn mower.

I think it's all down to price, the whizzo beast that is in the patent would be hugely more expensive to manufacture and would exponentially raise the price.
Would I buy one if it was ... say $500-$1000, I'm not sure.

 

[leaford]

Guys, the thing to remember about patents is, they don't have to work, and they don't have to ever be actually built. They just have to be an original idea sketched out in enough detail to describe the idea and it's implementation. Most patents are junk which doesn't actually work, but it secures the IDEA.

Also, I've seen several sites that claim to have patents. There are probably dozens of different patents involved here. Some of them maybe for something as simple as adding one more airhole to the existing design.

 

[TropicalBob]

That was a terrific explanation of the mechanics of e-smoking, MNZ. I enjoyed reading it -- and it should be a newbie stickie.

I, of course, agree most with your statement on the price of these! I've been furious from my introduction to e-smoking in January about the cost of our "toys" - and that's what they are, no more sophisticated than a cheap Chinese toy. The Ruyan pricing, particularly, is insane. I expect cost to have a relationship to expense to make and value received. That's not true of $45 disposable e-cigars. Or KISSBoxes, it seems.

Everything I've learned since I began e-smoking points to disposable units. And my hope now is that GreenCig doesn't go insane with $200 "starter kits". What should a battery cost? $10? $20? What about a dinky atomizer? $10? How about a cartridge attached to that atomizer so the thing lasts ONE WEEK? $5. So I should be able to buy an e-cig that is used one week, then replaced, for $25 or less (I'll recharge the battery, as I do my cell phone). Why, then, would the entry price be $100 or more? That's insane!

Arrrrgh. Of course, the "law" might catch up to these before they get out of their Yves ST. Laurent diapers. Can you say, "Bad baby!"

 

[leaford]

That's the thing, Bob. It'll never last a whole week unless it's Vegas e-cigar sized. The liquid only lasts so long, and you can only fit so much in a cartridge. I could deal with disposable atomizers if they were still refillable. But one atomizer per mini-sized cartridge is a stupid waste.

 

[MNZ]

Lets talk a little bit more about the inhalation process and what's going on inside a device when you inhale. For this lets consider a pen stlye as that's the device we are probably most familiar with.

The pen style draws in air from two locations, right at the end of the battery and also through the collar where the battery screws into the atomizer section.

The bulk of the air is drawn in through the collar area with only a small flow coming into the device from the end of the battery. The small air flow in from the battery end is used primarily to activate the air flow sensor and therefore the battery power to the heater coil and the timer circuit and LED.

Now lets consider this in some more detail.

When you inhale the bulk of the air arrives at the atomizer from the collar input. This appears to perform two distinct functions.

1. the indrawn air passes through the metal wool basket that surrounds the atomizer capsule. As the air passes through and out of the wool basket it carries with it tiny droplets of the juice that has soaked into the metal wool, into the heating chamber where the droplets are, by rapid high temperature heating, converted into the mist that we see and inhale.

2. When we inhale the resistance we feel to the draw is reducing the internal air pressure, this "pulls" the juice contained in the cartridge downwards towards the open end of the cartridge and onto the metal wool bridge thereby increasing the amount available by capillary action to be drawn into the metal wool basket from the bridge.

There may well be some atomization occuring with any juice that is present in the fibres we see in the centre core of the heating coil. It is however my belief that the bulk of the mist is created by the tiny droplets drawn from the metal wool basket by the relatively high velocity air flow we create when we inhale. I believe the primary functions of the fibres in the centre of the coil are to, help the coil retain it's shape as it rapidly heats and cools, therefore expanding and contracting. Also it may act as a thermal coupling and assists in conducting heat away more smoothly by retaining some heat so the coil cools slowly instead of rapidly. This is borne out by reports of rapid failures if the fibres are removed or once the burnt taste has stopped, therefore all the fibres have been reduced to a molten mess / ashes. In fact the very action of melting or burning these fibres will reduce the coil life by creating hot and cold spots on the metal of the coil so the heating and cooling processes are no longer even. This will setup stress fatigue in the metal and hasten it's breakage.

What I think is needed is a rethink on the design of the heater coil, that's why I suggested a spiral or circular design. Similar if you will, to the filament in a light bulb, and yes the light bulb has been changed !

Of course a light bulb works in a slightly different manner in that the delicate filament is active (hot) for a longer continuous time and is also working in an inert gas to protect it from rapid oxidation, burn out. The difficulty will be in creating suitable supports for the coil if the fibre interior is removed, which is what I'd like to see happen as I feel that is the weak link in the chain.

Sure batteries die, what can you expect from something that costs cents. The electronics fail, inherent problem with all micro-electronics, plus they are working in a potentially wet environment. But the primary failures seem to be the atomizers and without confirming research I'd suspect if the failed units were examined the majority of failures would be in the heating coil itself. And further more I'd suggest that the core fibres were either gone or severely damaged.

Another few cents worth from me.

Next time I think I might talk a bit about cartridge design and how they function and also give my thoughts on dripping, dry smoking and topping off of cartridges.

If anyone has anything they'd like me to discuss please feel free to offer it up ... instead of filling up this thread with that sort of stuff pm me with your suggestions. lets try and keep this thread going with good discussion and commentary.

 

[TropicalBob]

Again, nice post. Don't feel the need to pull back. This forum has room for "I'm new. What e-cig should I buy?" and threads like this one. Keep sharing your knowledge, Michael.

 

[TheEmperorOfIceCream]

The ultrasonic vaporiser that keeps being mentioned - did that ever get off the patent sheet and into existence (any application, even a tabletop model)?

 

[MNZ]

Not that I'm aware of emp, and I've been hunting around for it believe me.

I think two things might have scotched it, the cost of actually making the thing, it is a complicated beast, and also the final weight of the device, that's a sizable load of metal contraption and electronics to cart around, I'd estimate it would be in the region of 4-5 times the weight of current designs, perhaps more.

Janty call their latest bits of kit, kissboxes as in Keep It Simple Stupid, LCD indicators, pressure release valves, ultrasonic atomizer heads, extensive electronic control systems etc don't really fall into the K.I.S.S. design principal.

If it ever got built as designed we could end up sucking on something the size of a toilet roll, connected to an over the shoulder power supply that's needed to power up all the flashing lights and computer control systems !

 

[TheEmperorOfIceCream]

Yeah I know it. I also know that I'd wheel the damn thing around in a golf cart if it delivered the hit.

We are fools, ya know?

 

[jdrancor]

I see what you're saying about the air pulling a mist from the steel wool, which is then turned to vapor by the coil.

Here's what I tested. I pulled the steel wool bridge out of an old, burnt tasting but still functioning atomizer. I placed one drop of liquid directly on the coil/fibre. This yeilded two big healthy puffs of vapor, and then nothing at all. THEN, I placed some of the steel wool in the chamber and put one drop on the coil/fibre to wet it, and one drop on the steel wool. This yeilded about 24 good puffs, which then began to taper gradually. Also, there was the familiar gurgling sound. Oddly enough, the burnt taste has vanished - was it contained in the wire bridge? This doesn't seem possible. Anyhow, no burnt taste

SO. It appears, as MNZ says, that the liquid is not going straight from liquid to vapor, but from liquid to mist to vapor. Thus, the steel wool is a neccesary part of the design, creating a medium through which air can travel rapidly through tiny, liquid filled holes creating the mist prior to vaporization. SO, the wick idea would not be the best solution.

Additionally, I noted, at the center of the steel wool bridge, there is a solid bit of bent metal to retain the shape of the steel wool bridge, so that the cartridge, when pushed against it will not deform it. If this metal were eliminated, then there would be greater airflow through the wool, creating more mist, and more vapor.

So, maybe we start simply by replacing the fiber at the center of the coil with ceramic or glass or another non-conductive material? Micro perforations in it, if possible, would increase airflow. Then, changing the coil shape to spiral or horseshoe would increase the heated surface area. This would also drain battery life though, so maybe not. Removing the wide metal bar at the center of the bridge would increase airflow through the tiny holes too. for stiffness, perhaps replace with a wire rather than a bar. As far as getting the liquid to the wire mesh, this might be the problem to solve. I think the airflow could be a boon here.. or capillary action through a wick.. I don't have an answer to this at the moment.

But anyhow, replacing the fiber with glass or ceramic would probably take care of at least some of the burnt taste.

 

[RatInDaHat]

The only ultra sonic device similar, that i've seen, has been the portable ultra-sonic nebulizers. They are used for medication and not available without a prescription.

-Dusty-