Fire Maple Jetboil Clone

I'm glad not every company is as litigious as Apple. They claim they have the patent on the rectangle. Glad we don't see Mercedes suing car companies for having wheels and engines and windows, etc. :oD

Looks interesting… They added folding handles even though it has the neoprene sleeve, probably to avoid the lawsuits. Also, wind deflector seems like it'll block wind better than a normal JetBoil. So much plastic at the bottom.

Go to KOVEAUSA.com and you can get that from some nice folks in Los Angeles, California.

Comes with granola and a hot-tub ticket, too.

Why don't they do this? It would be more efficient way to heat water.
Make hole in both pot bottom and the lid.
Take some titanium tube with the exact diameter. if there will be some slices inside the tube it will make surface area greater and will increase heating. Place the tube inside the pot. Then allow the fire to burn inside that tube. The hot gas will escape just above the pot. It is possible to make several tubes in the pot. However this will result in more heavy pot…

Thoughts? Am I sick? :D

Gregory,

The big issue I could see with a heat exchanger inside the pot (and therefore having food in contact with the heat exchanger) is that food particles could clog up the slices in the tubes.

Also, wouldn't the tubes/slices in the tube be hotter and more likely to burn food that is in direct contact with those portions of the heat exchanger.

What you are talking about makes complete sense if you are only looking to boil water, where direct transfer of heat to water ASAP is efficient and important.

Stiring food inside the pot with a spork would also hit the tubes inside the pot….damage and making it difficult to use.

Anyway, just some quick thoughts off the top of my head.

-Tony

You have just described a fire-tube boiler, as used on steam locomotives.

Great for boiling water, but heavy, and obviously no good for food.

Tony and Stuart,

Yes, I'm thinking about boiling water. Cooking somehow slipped away from my mind… Maybe it's because I don't cook.

Regarding weight penalties, yes it would be more heavy. But I'm not sure it will be much heavier. For example, for Evernew 1.3L pot if we make all these out from titanium it will weigh 20-30 grams. not that big deal. Anyway how much weigh the heat exchanger?

BTW, for narrow and tall pots (like beer cans) which suffer from inefficiency because of small bottom area, this would be nice add-on.

IMHO.

Just my 2 cents guys. It's not I'm understanding the matter that good. I was thinking about this design for a while. It's good to receive some real feedback from experienced folks.

Thanks!

Gregory: I've longed for someone to mass produce such a pot. Yes, it would be only for boiling water as it would be bothersome to clean (although maybe a custom cut-out scrubbie on a stick could get in there and clean it. I'll also note that the very hot water and alkaline detergents in a home dishwasher are quite good at cleaning pots without scrubbing). But it could be more efficient than the "flux ring" HX on the bottom of pots.

What you call "slices" are usually called "fins" in heat exchange design. And, yes, those mounted inside the inner tube would also help increase efficiency.

From heat exchange design literature and what I've measured in different configurations, rough numbers:

simple pot on a stove: 30% efficient
pot with HX on the bottom: 50% efficient
pot with finned inner chimney (like your gas water heater): 70-80% efficient.

So there is the potential to more than half your fuel consumption and boil times compared to a non-HX pot. Also, the outside of the pot is always below boiling so many materials could be used as an insulating cozy to reduce avoid heat losses.

Multiple such tubes would be classic boiler design, but for reasons of weight, manufacturing costs and cleanup, a single inner tube with pretty dense fins at the bottom would be preferred.

I've prowled around cooking and thrift stoves to see if something was close enough to modify. Bundt pans have the inner tube but are far too wide, short and heavy. Stainless-steel insulated "thermos" mugs are water tight and the normal place to put liquid could be the "chimney" with water in the annular space around it. But that annular space is a very small volume.

Additional, obvious fuel-saving idea: You need a lid for a pot. If your lid is the bottom of another pot, with, say snow in it, efficiencies for your tube-in-tube pot could go over 80%. Then the melted snow / pre-heated water becomes the feed for your next pot of tea. No, it's not UL, but for extended winter camping and base-camp use, an extra 100-200 grams of pot could save many kg of fuel.

David, thank you for the post.
It's nice to know there are others who thought the exact same thing.
Have you tried some MYOG project with FOSTER cans? How the tube could be secured inside the pot and how to avoid leakage? Also these fins – any idea of how to produce and place them inside the tube? They should conduct the heat very well, hence there is a need to ensure they contact the tube firmly.

Gregory,

Wild idea came to mind, but I wonder if a CPU heat sink could be use inside of a pot?

It would require finding a way to separate the base of the CPU heat sink from the rest of the radiator, cut holes in the bottom of the pot, insert heat sink into the base of the pot….running the two tubes through the bottom of the pot and re-attaching to the base that would normally contact the CPU…..seal gaps between the two tubes and the holes drilled into the base of the pot.

Flame from the stove/esbit/alcohol stove….etc hits the base plate of the CPU heat sink and transfers heat inside of the pot via the radiator.

Hope that makes sense.

Anyway, just a rambling thought that popped up.

A small CPU heat sink is often small and light, which could work well.

-Tony

David: I easily get 50-60% efficiency using a simple pot, 5.5" to 6" diameter. The potential improvements than can be offered by a HX are somewhat limited.

I usually get about 50% efficiency, and have pushed that up to over 60%. (I hadn't brought enough fuel for the trip!)

Low to medium power, good windscreen, lid. Trade-off in boil time vs efficiency, for < 1 g of fuel.

Cheers

Guys, flame inside your pot gives you some good things:
0) The pot will never be hotter than 100 *C while there is water in it. The flame is inside the pot, and the external walls are not exposed to the flame. Hence it is possible to keep the pot within cozy while heating up the water in it! Therefore even more efficiency! Very convinient way to just take it and pour the hot water. Keep cozy always on (R) :)
1) The flame inside the pot => no need for windscreen. The pot is the windscreen. Double use :D
2) I'm sure you can make it UL. Even with the heating internal tube.
3) The internal cavity for burning alcohol (currently I consider only alcohol) must not be just a "tube". There is a plenty of ideas that could be implemented in order to make area of water/flame contact bigger. Imagine it is a tube at it's base, but the mid to upper part is like a accordion which has much greater area. I suppose that even in caldera systems a lot of heat escapes through radiation, space between the pot and the cone, heating the cone itself … Here we have most of the heat captured within this cavity. Higher pots will be more efficient.

Here it is. It must not be the exact shape, but I think you got the idea. The bottom of that tube is absolutely round for making it easier to fix it into pot hole. This is achieved by a cone shape with much greater top diameter.

Isn't what you are describing essentially a backcountry boiler by boiler works? I like the idea and like the double duty idea to. basically you boil the water on the inside and you can bring a frying pan to cook on the top while you are boiling water. It weighs a little more but you dont carry a pot, lid or fuel. and it can be used as a water bottle. I almost bought one this year. Maybe next year for fun.

Yup it is. Most of those volcano or kelly kettle designs are made for wood burning however. I haven't seen any that are designed to work with other fuel sources. And I'm not sure about the backcountry boiler but most do not seem to use fins for better heat transfer.