Esbit burner testing

Adam, you've got an interesting occupation :)

A quote from Jason Quick, notice height set for esbit:

So, what have I now got now?…. a dedicated Esbit burning mug/pot that nests inside a custom caldera cone from TD, set to the height of 1.25 inches above my MYOG Brian Green Esbit Tray stove. Happy as a pig in ____!

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=72925

From Jason's description, he isn't getting as good fuel economy. He says he managed to get a cup to boil on 7 grams. I wonder why?

Yep, my job is very interesting :-)

Jason's cone may be taking the flame off the center of the pot and dumping it out through the hole where the pot handles are. Maybe it's because of the pot being titanium. Maybe the beer band was not set at the proper height.

The heat discoloration on the cones tell a lot about air flow within.

I created a alcohol burner with a height of .005 inches to match the BGET. Will test it today.

edited to say .005 should read: .500 or 1/2"

"I created a alcohol burner with a height of .005 inches…"
:0 Surely this is a typo?

Thank you William, 1/2" in height. Sometimes I'm a little bass akwards :) Bob would have caught that one also:)

Bob would have picked up "bass awkwards" faster than I did…took me a few seconds to get it :-)

Bob would also have continued to contribute to this thread. Threads like this are where real new groundbreaking stuff gets generated…in a few years time what is in this thread standard practise, but for now, we need people like Bob around to help drive things forward.

[There is a good reason why Professors get tenured, and Universities are pretty hesitant to get rid of them even if they are cranky cows and awful for many people to work with. They have that particular something that is sometimes needed to get things done and innovate…Universities try to find a balance of people, not just having that balance entirely within every one person!]

Anyway, back to topic!

The Jason Quick Set up, hmmm. I had a thought that maybe as its a fairly square pot, the total surface area of water per unit volume, that is exposed to the heat (not just the flame) within the cone isn't high enough. The beer can pots, despite conventional wisdom that they are too tall, in the cone situation might actually work out a lot better as heat is trapped inside the cone for longer.

I agree, the large flat bottom could channel that heat straight out. Handle holes on cone might not be a good thing-counter productive.

A test for this, would be two cones with identical pots, one with handle hole, one without.

Did three tests with new tray that holds two 4 gram tablets side by side. One of them boiled 2 cups and burned for an additional 1 min. The other two got up to 205 degrees.

Looks like 2-1/2 tablets will easily boil 2 cups in the field.

I'll do some tests with a Caldera Cone later.

In a thread, Eric Lundquist linked us to a page at trail Designs that showed a Evernew 400ml Sidewinder Bundle that had a modified Gram Cracker that sat flat on the ground. Has anyone used that bundle from TD?

http://www.traildesigns.com/stoves/evernew-400ml-cup-sidewinder-ti-tri-bundle

This is the Modified Gram Cracker furnished with the 400ml bundle:

Last night I did 3 tests with a cone. The first got only a 200 degree temp. I watched the flame pattern under the cone and could see the flame going off center so for the next 2 tests I blocked off the opening under the locking mechanism of the cone. Low and behold, for the next 2 tests I got the boil without a problem. Starting water temps were around 75 degrees, using an aluminum Foster pot, 2.5 cup capacity. Used two 4 gram esbits side by side in a new stainless steel esbit tray. Will do more tests today.

Windscreen design and closeness to the pot matters :) The 1.25" seems to be the sweetness we've been looking for.

Eric, have you been watching the water boil?

Do Trail designs alter the number of inlet/outlet ports on their different cones?

Burning only two 4g tablets, with relatively low water volume (thermal mass) and going for efficiency over outright speed, I'm guessing that we'd prefer a caldera cone with below average area of vents and ports here…

Adam, I took a look at all the photos on google and I get the impression the opening do vary. Seems like the upper holes remain the same and the bottom ones vary.

https://www.google.com/search?q=caldera+titanium+cones&biw=1366&bih=624&
source=lnms&tbm=isch&sa=X&ei=FR2GVZWWCYaiyQS_goDgDQ&ved=0CAcQ_AUoAg

I'm sure Trail Designs will have something interesting within the next month after reading all this info on esbit :-))

I had to suspend testing today, high humidity and low barometric pressure is here with storms passing thru.

I may have some photos tomorrow of my cone and windscreen that I've been using and also the tray.

I've had good success with just 2 four gram tablets. Add 2 more grams and a boil out in the field is highly possible. For some, 200 degree water temps will be just fine.

Hey Dan

so this cone and can is what you were working with for those tests?

https://www.youtube.com/watch?t=78&v=akHDTbepNNE

Excepting a different main ridgeline placement in order to get the 1.25" height above the Esbit on your custom tray?

The bottom hole is huge on that cone. Don't really know why they bother punching the two other bottom breather holes, no point in them at all with a join hole that big. Really, I would have thought that the exhaust hole area should be approximately equal to the inlet hole area (assuming exhaust gases are of the same volume as the inlet air after the chemical reaction). By my count in your video, there are 8 exhaust outlets, two normal inlets plus the gaping hole.

Out of interest, what weight do your aluminium can lids normally come to? Ruta Locura's CF lids for that size are 5g.

Cheers

Adam, my recent tests were with a prototype titanium cone and a stainless steel straight wall windscreen using a stainless steel mesh pot support.

I recently sent out a foster pot made to fit 3/4″ lower in the caldera cone you see in the video you linked to. I had a special sale here on BPL a while ago offering the special pot for members only. It lowers the pot so it sits 1 inch above the StarLyte burners, no shim needed. I’ll include a photo of the pot side by side to show the difference in ridgeline locations.

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/mb_post_form.html?po=edit&note_id=653006&forum_thread_id=76459

The weight of the lid in the video is approximately 5 grams. The lid I recently used in my tests weighs between 3 and 4 grams. My electronic postal scale bounces back and forth between 3 and 4 grams. The weight loss comes from removing the pull tab and adding a new found tape that resists heat from the boiling water. The adhesive on the tape is special heat resistant stuff.

Dan a couple things,

What were the results in your setup in this video?
https://youtu.be/qVqTYQDd_eI

As far as the modified graham cracker, I don't have that setup and never used one, I would assume though that it would not work as well as a BGET tray style stove because it doesn't contain the liquid which we know is key. I would think if you need a tray to sit on the ground you'd have better performance with something like a legless BGET or just a tray in the link below that Stick made.
http://sticksblog.com/2012/06/09/sul-cook-kit/

The other questions I have are how did you attach the carbon felt to your pots? I like it.

And approximately what is the distance of your straight windscreen from your pot? Does having a windscreen tighter to the pot work better with esbit?

Jameson, that video was made to demo the Ti cone made special for the stainless pot with ridgeline. The kit was really nice, made only 6 because of TD’s policies for resale type of thing. Never did any real testing with that esbit burner shown in the video using the 4 gram tablets.

You’re right about the esbit tray needing to be closed on the ends to prevent loss of the liquefied esbit. It’s interesting how change occurs during a testing period such as we are experiencing here. Info coming in from all directions. Because of it I am making changes. I’ve cut off the legs of the BGET’s and adhered it to a disc of carbon felt. I have found that the metal disc conducted heat away from the tray and caused incomplete burn of the liquid, small amount but noticeable. My tests with the 2 four gram tabs led me to discover that so I cut the legs off to be sure of increased efficiency. Little things add up ;)

I created a shallow tray for the 2 side by side 4 gram tablets. I didn’t want to modify/widen the BGET so the 2 fours could be side by side. The 2 fours need to have oxygen all around their sides to burn efficiently. The 14 gram tablet needs 2 sides to be denied oxygen to burn efficiently.

The carbon felt is adhered to the pot with high heat resistant double sided adhesive that comes on a roll. The entire surface of the felt is covered with it. I’m in the process of testing a pot with double layer of felt to see if it will withstand the weight of the pot when it has 2 cups of water in it while being supported by the stainless steel EZ-Fold windscreen.

The windscreen was 1/4″ distance from the sides of the pot during testing when I got the boils. I was using a stainless steel hardware cloth pot support that is 3″ in diameter. The bottom of the pot nestles nicely into the support.

The two trays in the photo fit into the small plastic storage container. Total weight of trays adhered to carbon felt discs and storage container is 7 grams.

I really like your new lid Dan, that's a nifty solution.

I figured that you could quite easily adjust the exact placement of the main ridgeline depending on what height you wanted, for what stove, and you've already done that in spades. I think this is a much nicer solution, and, advantage to beverage can pots over pots that are dependent on either a rolled lip or a beer band or fibreglass wick to set the height with a CCone. Less additional gear, less points of failure. Win.

Hi Adam, thanks. From this day forward the Foster pot lids will have the tape lifting design. 4 grams per lid….now that is uberlight :) The BGET's will be without legs and attached to a carbon felt disc.

When I get a set of those off you in the near future, I'll put them on some scientific scales here in the lab and give you a more precise (for that individual) measurement ;-)

You got access to all the fun stuff. Someday create a thread about the wallaby that's on the endangered list and how you track/locate with thermal imaging.

Sure. We have an honours student whose project that is. At the moment its simple testing (eg, can we see Wallaby, what time of day/temp, etc), but hopefully sometime in the next few weeks we'll head up to the Flinders Ranges (also a great bushwalking stomping ground…) to find an isolated colony of them to test some flying methods on.

I need to dig up a lazy susan from somewhere so I can do some thermal stove videos.

One thing we've noticed flying the thermal camera around in preliminary trials, is that water tanks show up well…we can see the level of the water perfectly. Me thinks it might be interesting to get thermal video of the water within a pot while it boils, to see how heat moves through it. I'm guessing it will be different with/without windscreen/caldera cone…whether its different enough to tell I'm not sure. The hottest temperature we've recorded so far with the thermal camera is mid 70C range (exposed soil on a warm, 30C day). The camera does some kind of regular, internal calibration of its range, in order to record everything that it is seeing. I have a feeling that if the temperature range it is viewing is very large then its ability to tell fine changes in temperature will be reduced. Its possible that the very high temperatures of the combustion gasses from the burning fuel will swamp the readings of the actual water. But I can't be sure until I try it. Working with FLIR is new for us in Remote Sensing.

In thinking about this problem on my way to the lab this morning, I wondered what would the benefits be. Well, if the water in the pot is very stratified (quite possible, especially if its heating up very fast), it might be beneficial to STIR the water 1-x times during the heating process. The reason being that there will be layers of hotter water at the bottom of the pot (especially early on). The hotter water won't absorb as much heat energy as cold water. By giving it a quick stir, and mixing up the water, the water at the bottom closer to the heat source is now colder and thus can absorb heat energy more efficiently.

There would be a trade off between taking off the lid to stir and the benefits of de-stratifying the water. Constantly stirring, for example, would probably be a bad idea. Or it might be about the same as not stirring at all but keeping the lid on. There might be an optimum number of times, and when, to stir. Or, even once optimised, the net benefit in field use might be so small its not worth the thought, especially if we are constrained to things like size of fuel tabs and banking on poor conditions anyway (eg, the 2*4g tab target is a good one…the idea being that we try to beat it by a good margin in optimum field conditions, so that in poorer conditions we can still get close to a boil).

Adam I'll send you some esbit stuff tomorrow for thermal imaging.

Canister stoves put out a ton of btu's fast and the water can absorb the heat quickly as we all have heard folks say about how "fast" they can heat their water. Well me thinks the esbit trays that have bread pan corners have the liquefied esbit being burned in a "radical" fashion, giving off lots of btu's quickly and so we place the esbit in close proximity to the pot bottom(just like a canister stove) the water can and will absorb the heat. Me thinks the faster the water can heat up at the bottom of the pot the better so it will rise and cause the colder water to fall to the bottom to absorb that radical heat :) You'll be able to see the thermal image of rising water and that will be so enlightening you'll have a grin on your face that extends from ear to ear LOL When we boil water at home on the kitchen stove using a large 1 gallon capacity pot at some point we can begin to see wavy looking patterns in the water indicating that there is movement of sorts within.

Sounds cool. I have a Ti cone for my BPL 1350 pot, as well as various stoves and stuff lying about. I have your Starlyte and Starlyte XL, and the BGET you sent me (which was standard dimensions…not optimised for 4g). When I set up to get video, I'll do a run with them all for interest' sake.

Have a couple of canister stoves I will run through it as well, and of course a home kettle…be interesting to see this rising and falling if that is what is happening…something like that for sure at the hotter temperatures as there a physical re positioning of water molecules within the water body definitely occurs.

I’ll send along a tray for the 4 gram tablets.

Remember the shadow graph photos made by one of your country men “Tony”

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Recent discussion about shut off valves/switches in another thread made me think of the mini esbitmizer tray. 2 four gram tablets fit nice side by side. If an emergency should arise and have to shut if off…just close the lid portion of the valve.:)

Find a large tray with sliding lid that will cover a whole 14 gram tablet ;) Show that feature if a Ranger asks what kind of stove and fuel do you have etc.

Dan,

So did you find the carbon felt pad combined with the "legless" BGET tab holder worked better than a regular BGET holder? i.e. better burn of remaining liquid fuel, faster boil times, etc.

I assume the distance from top of tablet(s) to the bottom of the pot saw about the same as with the original BGET. No?
This top-of-tab-to-pot bottom distance appears to be crucial with ESBIT.