Yet another (portable) RMH

Michael Skowronski wrote:Hi Lens,

In another post you said, "I have seen a picture of a rocket lamp that runs on twigs." Any chance you have a copy/link to that picture? I'd like to see it.

Thanks,
Michael Skowronski

Try this:

http://bioenergylists.org/stovesdoc/Still/lantern/lantern.html

I don't know that this is the best way to to make light from wood. It is a quick lamp so we can see nasty bugs that sting as well as each other. I do think making light from wood is a worthy area of study for some off grid (as in off the manufacturing grid too) uses.... though using animal fat is probably easier. However, nobody has spent the time.

Len, That is so cool...or should I say HOT! Thanks for posting that, it leads me to some awesome ideas!

Well I have finally got some more pictures... they don't show much. I haven't had the time to do much work on things ... life has been too full.

the first pic is of the bottom of the slab after burn. Those are not finger prints but condensate marks from where it formed drops.


This one shows the intake pipe and the strut to hold it up. The exhaust can be seen at the bottom center of the far end if you look closely.


This last one tries to show the puddle of water left after a burn.

Len, wakey wakey!

Well, thrown the one i had scavenged in the skip, and got given this one!



I was wondering. How did you do the horizontal cut on yours? I would like to have à nice cut!

Thanksalot.

Max.

Satamax Antone wrote:Len, wakey wakey!

Ya, I haven't been around much lately. Pretty busy with SW development in Ubuntu Studio.

Well, thrown the one i had scavenged in the skip, and got given this one!
I was wondering. How did you do the horizontal cut on yours? I would like to have à nice cut!

I used an angle grinder with a cutting disk on it. I had to do work to get things reasonably flat afterwards. Plasma cutter would probably be best or even cutting torch. But I have none of these things. It was a long, noisy job. It happened that the cutting disks were on sale for about $5 a 15 pack. They were actually a bit big for my grinder (the center hole), but I was able to make it work.

Len

Okay Len, thanks a lot.

Well, i'll have to work like you. I have no prob cutting a straight line, or rather good straight'ish one with most of the tools, as long as i have à line to guide me. But with the angle grinder, there's soo much sparks, that i can't see the line! One trick i've found, cut upwards, instead of cutting towards the bottom, i go towards the top or the line in front of my angle grinder. Works way better, tho, it's still complicated. By the way, Donkey, Canyon and Peterberg are onto a new type of rocket, a batch box one. And this one might become a batch box rocket.

Satamax Antone wrote:Okay Len, thanks a lot.

Well, i'll have to work like you. I have no prob cutting a straight line, or rather good straight'ish one with most of the tools, as long as i have à line to guide me. But with the angle grinder, there's soo much sparks, that i can't see the line! One trick i've found, cut upwards, instead of cutting towards the bottom, i go towards the top or the line in front of my angle grinder. Works way better, tho, it's still complicated.

I make sure the disk is going into the plate so most of the sparks go to the other side of the plate from what I am working on. I set the guard so I can rest it on the plate to make it easier to hold the unit straight.

By the way, Donkey, Canyon and Peterberg are onto a new type of rocket, a batch box one. And this one might become a batch box rocket.

Batch burning makes more sense. The RMH has always been a masonry heater for cheap and masonry heaters are batch devices. With top down burning the same principles should work for us.

Len Ovens ; I bumped this up so that I could ask if you would do your fellow Permies an Update, with all the buzz about useing 1/2 barrel as bells your thoughts
here or in a new Forum Thread would be very instructive ! For the Good of the Craft ! Thanks big AL !

allen lumley wrote:Len Ovens ; I bumped this up so that I could ask if you would do your fellow Permies an Update, with all the buzz about useing 1/2 barrel as bells your thoughts
here or in a new Forum Thread would be very instructive ! For the Good of the Craft ! Thanks big AL !

I haven't had a chance to do much more work on this. I got into some software dev stuff and then my work got lengthened by about an hour and has turned out to be too much for my body (feet and knees). SO while I do have the stuff moved into the house, I have not yet worked on it or set it up. I got part way through putting the first row of brick on the barrel and there it sits.

My thoughts on bells:
- they are better than long pipe runs in general.
- Though most people feed them from the bottom, I think mid or at least a little higher than exhaust is better. Most of the brick ones have the input feeding in an upward direction, so on a bench type bell where it is not very high and the input is horizontal, I think there should at least be a wedge to deflect the flow up a bit to keep it from coupling with the exhaust too directly. I have used top feed with no problem.
- I have the input go half way across the bell, I am going to cut that back as it left a cool spot where the pipe was. I will at least cut the top of that off.
- Mass goes on top. The bottom of mine even after two hours burn was still cool enough on the bottom to have sitting water from condensate. (this matches with point one above... if there is water on the bottom the temp of that surface and the exhaust, must be less than 100C)
- Insulating the bottom may help with the water problem. I would still like to know if other people have checked the output end of their bench (or the lowest end) for water after a burn. In a cob bench this could be a bigger problem than what I have as when the metal pipe rusts through the cob under would get soggy and could subside leaving a hole where fumes could enter the living space. (I understand there have been cob based RMH operating for many years with no visible problems. It could be that the cob could be insulating enough already)

My thoughts/observations on RMH that are different from others thoughts:
- mass on the outside of the barrel is ok so long as it is not insulating. Clay brick or dense fire brick conduct heat faster than air and should keep things cool enough for the rocket to keep working. I have not had any trouble with mass on the barrel and others have built the barrel out of brick.
- mass on the barrel keeps the room from over heating. It is single layer of brick and so the heater is still quite responsive and heat hits the room in a timely manner. (most masonry heaters are double skin in North America)

Maybe more later...