Pots With Heat Exchangers

[DAN-Y]

Thanks for all your research David. I ordered 3 of the $13 ebay pots. When they arrive I’ll send you one and one for Roger.

plus weird pot/frypan/lid thing for sauté-ing two goldfish (green trim on right).

Made me laugh! :-)

https://youtu.be/s9qwfEgscNg

[David Thomas]

“Franco that told us to leave the handles separated when heating and they will remain cool enough to lift without aids”

And, as DanY points out, a good windscreen can do a lot to keep handles cool.

To add to my list of wanna-haves on a HX pot: asymmetric fins on the bottom/sides such that the handle area has 1) more heat extracted below it and/or 2) hot gases are diverted to the rest (the other 90%) of the perimeter.  The HX kitchen pot I recently got does that nicely with the fins going north-south, while the handles are on the east and west sides.  It works pretty well:

Or, (I just added this to my HX treatise above): when you remove enough heat from the exhaust gases, you can use a neoprene cozy.  You could go full-cozy like JetBoil and you’d have a somewhat insulated mug.  Or just a 4 cm band – enough to secure grab the pot and pour.  A 4 cm band of neoprene weighs less than either of the metal handles shown above.  Get a $10 used wetsuit from a Goodwill thrift store and you can find every possible diameter / circumference depending on where you cut the arms and legs.  Or is there a neoprene CCF tape?

[David Thomas]

To answer my own question above, here’s an adhesive, neoprene-EPDM, CCF tape that, for two wraps (a 2-inch-wide band) around a 5-inch diameter pot would add 3 grams.  $19 for 50 feet.  $0.50/pot.

https://www.grainger.com/product/GRAINGER-APPROVED-Neoprene-EPDM-SBR-Sponge-Stripping-420C18?ef_id=EAIaIQobChMIhZDUq-OH4wIVDtRkCh0h-QWxEAAYAyAAEgI8k_D_BwE:G:s&s_kwcid=AL!2966!3!317451745656!b!!g!!

[DAN-Y]

neoprene fabric by the yard

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=neoprene+fabric+by+the+yard&_sacat=47354

Gary Dunkel found out for us in the Sterno Inferno thread it makes for a good insulator but adds nothing for heating the water faster.

[Roger Caffin]

@Dan

The Bulin handles by themselves are 44 g. The steel clip on the side of the pot is probably another 20+ g. That’s 65+ g. The MSR potlifter is 27 – 29 g. Well, that’s a factor of 2x. Oh, the agony!

Mind you, if you took the steel handle and steel clip off and replaced them with CP Ti sheet and Ti wire, it could get to be a bit of a challenge. The Ti is about 1/2 the density of steel.

Cheers

[Roger Caffin]

a neoprene cozy.
I have noticed that the Jetboil cozy does not melt, so obviously the HX fins are extracting a lot of heat from the gases. Interesting.

Cheers

[Roger Caffin]

I ordered 3 of the $13 ebay pots. When they arrive I’ll send you one and one for Roger.

But that means I might have to DO something with them! Gasp! Horror!
Hum … thinks … workshop … I’m on.

Cheers

[DAN-Y]

Yes Roger, something to do in the winter months ahead :) then compare notes with David. Rip the handles off and see how much weight difference there is between yours and Davids. Make it work! share the experience with your wife when out and about.

[Roger Caffin]

My wife leaves details about the pots & stoves to me. She is far more interested in the contents of the pot! And how soon the contents reach her.

Cheers

[DAN-Y]

Strange thing happened while doing some tests the other day. The first test showed I used 2gr of fuel to boil 500ml. All items relating to the test were of equal temperature. Water, air, pot, lid, canister, heat exchange skirt attached to pot…all the same temp. All tests after that temps of the canister got colder and colder and fuel usage changed for the worse. The pot and skirt were HX.

[DAN-Y]

And how soon the contents reach her.

I know you do your best to satisfy….the upcoming HX pot and your DIY HX skirt will speed up the process. She will be well pleased for the increase in speed :-)

[DAN-Y]

This is a Sterno Pot, handles 3x lighter than Bulin. Yes I know, you need 1ltr+

[obx hiker]

FWIW I’ve been using, /boiling water with a reflectix cozy with HVAC foil tape top and bottom on an original jetboil pot for @ 6 years. The same one. The green is the reflectix and silver the HVAC foil tape. The taped top and bottom keeps liquid out of the otherwize open cells and probably helps the bottom edge with the heat. Like my twist-tie lid-loop? Boil @ 12 oz water and add food, let sit @ 20 minutes and it’s still warm.

[DAN-Y]

The small amount that I’ve read makes me think the Jet boils have a regulator on the stove portion. It’s max heat is such that there is no overflowing of flames outside the HX fins that would cause any ill effect on the cozy. Just like some trucks/vehicles have governers on the engines to control max speed while on the roads….no petal to the metal;)

@obxcola, do you find that to be true about how high the flame can get on your unit, is it limited?

[DAN-Y]

Strange thing happened while doing some tests the other day. The first test showed I used 2gr of fuel to boil 500ml. All items relating to the test were of equal temperature. Water, air, pot, lid, canister, heat exchange skirt attached to pot…all the same temp. All tests after that temps of the canister got colder and colder and fuel usage changed for the worse. The pot and skirt were HX.

It happened again this morning. I’m using a net wt. 220gr Coleman canister of fuel. All materials sat on the table in my garage over night, all same temperature. Weighed canister with stove attached and then went through the motions and then fired it up, half throttle. Weighed canister with stove attached….used 2 grams of fuel. There is no bullshit going on here, just the honest truth. All you canister stove users take notes. Go out and get a large canister of fuel and do some testing.

David do a test with your BRS please :-) Tomorrow in your barn.

[Casey Bowden]

I believe you, but wonder about rounding. Specifically, what if you start with 100.51 grams of fuel (which the scale rounds up to 101 grams) and finish with 103.49 grams (which the scale rounds down to 103 grams). If so you have used 3 grams, which is still really good, but the scale will indicate you’ve only used 2 grams.

[DAN-Y]

Casey, I like rounding. Let’s say it’s 3gr. The weights I gave for my initial 10 tests were rounded to 5 grams. The 10 test were made one right after the other in kinda like a non stop marathon water boil contest :-) There were 2 major interests while performing the tests, pyhsical stove performance and fuel used per boil. The stove I’m using has been modified to fit well between the HX fins. It has 4 support legs. While the pot is on the stove(without water in it), I can tilt it at a 45 degree angle and it doesn’t slide off.

I use a USPS scale to measure the weight of the canister. I weigh it 5-6 times and take the heaviest weight displayed.

My scale:

Extra large, easy-to-read 1.3″, LCD display
USB Port to Download Weight to your Computer
Power:Star IV power adapter (included) or 3 AA batteries (not included)
Weighing Range: 0.1 oz. to 10lbs. (1 gram to 5 kilograms)

[David Thomas]

I believe those are the numbers you saw, but I don’t believe that only 2 grams of butane got burned to boil 500g of water.  Working in the English system because it was good enough for James Watt:

2 grams/453.6 = 0.00441 pounds.

Gross* heat of combustion of n-butane: 21,308 BTU/pound (propane is only 1.7% more).

Maximum heat released (*if you condense all the water vapor) in 2 grams of butane = the product of the above quantities: 94 BTUs

Heat required to rise 500g/453.6g/lb = 1.1 pounds of water from 68 to 212 (144 degrees) = 158 BTUs.

And since it eventually boiled, one should use net (19,680 BTU/pound) not gross heat values.

You’ve discovered not-such-cold fusion!  Use a helium detector in the exhaust.  Or a Geiger counter.

But I’ll try the BRS-3000T at a moderate flame with the Optimus HX pot and with the Bulin S2400.  I’ve posted results at max output, but not at a lower setting.

[Jerry Adams]

” Working in the English system because it was good enough for James Watt”

When will we abandon the “English” system, it’s a national disgrace.  It’s insanity.

I know the French invented the metric system, but they’re not that bad…

[Stormin]

The English system is so outdated, even we stopped using it in the 70’s.!

[Jon Fong / Flat Cat Gear]

There is a possibility that the canister is getting colder and moisture is condensing on the canister.  A few grams of water isn’t much volume.  Something to think about anyway.

[David Thomas]

All right, all you Francophiles, what’s this*?

The heat of combustion of butane (C4H10) is −2878 kJ/mol = 49.5 kJ/gram = 11.8 calories released / gram of butane burned.

*The inside of Napoleon’s coat.

[Roger Caffin]

Firkins per furlong …

Cheers

[Jerry Adams]

inside of Napolean’s coat???  ha, ha, ha,…

[DAN-Y]

*The inside of Napoleon’s coat.

Your photo is of a right handed person. Napoleon was left handed.

 

 

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