Pete Peterson

I only just nos read a brief description of the willow feeding system , but it reminded me of my even  simpler method, ( but I'm going to learn more about it and see what about it that I can use also).

I have  been composting my waste for a few years. It js ridiculously easy and simp!e (as long as I ignored .most people's advice)!

Most people overcomplicate it greatly. The way I have been doing it is even easier and simpler than almost anything .

All I do is use a simp!e 5 gallon bucket and put a litt!e mulch and leaves to cover each " deposit.".
When it's full I simply bring it to my compositing area outside where there are 2 large 40 gallon trash cans ( plastic) with a few drain holes in the bottoms.  Those are my composters.

When the 5 gallon poop pal is full, I just dump it into one 40 gal trash "can" and put the lid back on. I also drape a camo tarp over it to protect it from sun damage and keep out any escaping odors.

Here is the most important part: DO NOTHING!!

No need to shovel and turn it ever. Also no need to worry about " correct" carbon/ nitrogen ratios, aeration, becoming anaerobic, or anything else.  After one 40 gal trash can is full (takes over a year for 1 person) , I just let it sit there for another full year. (In the meantime I use the 2nd 40 gal can to dump my other filled 5 gal pop pots).

So after the year or so of letting the filled 40 gal can sit there, I just dump it out in a pile right there and cover it with  a tarp to keep rain out. It does not smell bad by then or look like poop. After another year of further breaking down while being down on the earth with all the worms and fungi, , its ready to fertilize my  trees with.

Its so easy and simple.  I'm sure places in the 40 gal trash cans become anaerobic . But it doesn't matter in the end because it all be ones aerobic in the end.

Anyway,  I think its interesting how easy this works and how you can ignore all the normal " correct" composting advice and end up with awesome compost with hardly any work.


Adios!!
Pete

I know this post was 8 years ago.... but I like your idea and am also interestex in making a ferrocement tub like you speak of.
Are you using it now? I was wondering if it held up good and was  worth doing?

Did you find a suitable commercial heat exchanger? I know  most people would prefer to bui!d with only dirt and sticks ( just jokin, I love this site and forums! ) but sometimes its hard to beat a commercially made thing like a heat exchanger If its well designed and super efficient.

Adios!

Thanks Benjamin,
This link has pics of examples : https://ibb.co/album/D4xPb4 .  The Hookway retort is basically what I'm talking about. The Hornito retort is pretty much the same thing  as far as I can tell.  
The wood to be biochar-ed is in a sealed drum ( in my case I want it to be made from stone). The rocket stove ventilation is separate . I guess its possible to run the rocket exhaust through the biochar chamber if there was zero oxygen left in it, but these are tried proven designs meant to be sealed except for the wood gas that exits a small tube. Depending on the design, the tube can go down and just hook into the burn chamber.Then after the moisture is vented and good wood gas comes out, the gas fuels the who!e shebang and you don't have to add any more wood. There's another pic attached that's basically the same thing made a smaller size on Instructibles .

I was thinking about using a j- tube with the feed tube outside, and the burn tunnel and riser inside the retort. Then the metal riser exits through a sealed hole in the top. The bare metal of the riser heats the kiln from inside.
I want to make the j-tube mostly from stone and refractory or maybe cob but where I live in Hawaii there's no dirt here really...just a lot of compost. Some of it is really old and black muck in rare places, but it not clay or like minerals or sand. I kind of dont think its right for cob.
But we have tons of volcanic basalt of  a!l size. Its relatively  light with air holes.
I want the bottom part of the riser to be masonry,but a straight metal one needs to be connected to the riser hole in the bottom and go out the top of the retort.  That will need to be replaced over time, but  its not that long.

Since I want to make a bigger retort than 55 gals, I wanted to increase the surface area of hot duct so it can heat up the bigger space. If an S - shaped riser won't work, I could make it so there 2 smaller risers ( one feed tube and one burn chamber but 2 risers).  Either that or put a larger diameter duct inside the retort with reducers at the inlet and outlet.

I don't really know much or understand the tlud ones. Can it burn up waste plastic with no smoke?
Because that's my one main goal, not biochar so much ....and also I want to store some of the gas for fuel for cooking, etc.
Also carbon is left over still and  that can be used as fuel, sequestered, etc

I mainly need help with figuring out how to make a relatively airtight retort with rocks or masonry. I was thinking of a honeycomb design. I have basalt rock of all sizes.  The inside needs to be lined to fill cracks between rocks and make it mostly airtight.. I have waterglass and perlite ( insulating), so I thought about smearing that mix on the inside and filling all the cracks with it. I never used waterglass so I dont know if it will just end up cracking off? Or should I use metal lathe or chicken wire first on the inside and then cover it with refractory ?( I read water glass can protect metal from heat and oxidation. )
(I would also need a lid of some kind. I can make it heavy so its held down tight by gravity and maybe add a rope gasket)

Hello,
I wish to make a masonry version of the metal barrel type biochar kilns that have a rocket stove burn chamber and riser running thorough the middle of a metal barrel to heat up the wood/ biochar contained  in the barrel. Instead of a metal barel, i want to make a bigger one out of rocks ( porous basalt). because I have tons of it. Its light because of many  holes so its a bit insulating.    I would need some kind of refractory coating or mortar to fill in the inside cracks since it must be mostly air tight. I thought about mixing refractory cement or mortar with perlite for more insulation. I also have waterglass but never used it before.
Im not sure what to use. I want it to be durable, not just temporary.  Any help with construction methods would be most appreciated. I  was thinking about making it round

Also, I want to try to make the riser more than twice the normal length but S- shaped. ....so there is more surface area to heat the inside of the stone retort instead of just going straight up.
Most of the riser has to be made from metal duct work to transfer the heat to the retort.

Is that kind of riser going to work though? I put a pic here. I think it should still pull the draft ok.

Thank you Phil! That is an awesome idea!

Great minds think alike I was recently thinking about a similar idea . But instead of burning all the gasses up inside the riser area, the tube could go to the outside and bubble up through some water to cool/ clean it and collect in an upturned tank .....like a methane digester setup. And then it could be used as fuel for cooking stoves, etc.

I was thinking of using a pressure pot (normally used for spraying) - attached pic).. I got that idea from a guy on YouTube who made a wood gasifier out of such a pressure pot. He replaced the rubber basket with a wood stove rope gasket.

There could another tube that goes to the riser ( like you said) with a valve(s) so if the fuel collection tank is fuel, the extra gasses could be burned in the riser like in your design.

Those pressure pots are made from thick steel or stainless  steel but I'm still not sure how long they will last in the high heat. It might be better to use recycled drums like you mentioned and replace when necessary. Those pressure pots are not cheap, but if they last long,  it would be worth it to me. They make them in all sizes. A 10 gallon one would fit a lot of plastic trash and be very convenient . Even a 5 gallon size would fit quite a bit if stuffed.

But if they do not last long, it might be better to use recycled drums like you mentioned and replace them when needed.

In your design, does the top of the skip bin protrube up outside of the riser very far, or just a little ? I'm thinking most if it is inside the riser? I'm guessing you have to weld a top on it?

I was born in 1974 long before the internet and had to use libraries for info and ideas, so I really appreciate the power of the internet. It dramatically speeds up the evolution of ideas ( when people are not looking a cats

Thank you again for sharing!!

Pete

Thank you Glen, Phil, and Thomas for the  very helpful replies!!
I meant to reply sooner but was unable to until now.

After reading the replies, I think my plans are much too large for my needs and will be too hot anyway.
I compost, so most of my garbage that I want to burn is plastic.I live alone so I do not create that much trash, but I cannot drive due to an illness and I have about 30 big trash bags of mainly plastic  piled up from the past 4 years as I was recovering and moving to my land ( moving seems to generate a lot extra trash for me).

So normally I would not need a huge incinerator but I wanted to make one big enough to handle a full 30 gal trash bag at least .

Maybe its dillusional, but I envision throwing filled 30 gal trash bags in without opening them and watching them easily disappear with little smoke!  I know with the right design, that is possible though.

Also I really wanted to use my stainless cloth dryer drum because they are great fire " pits" with not much smoke all by themselves (using wood though) , so I thought coupled with a rocket stove, it would be extra efficient, p!us it's big enough to hold a filled trash bag. Plus using a drum like that would make possible a true downdraft design.

I understand how it might melt though... but my design is a downdraft one ,so my thinking was that  the stainless drum would be in the coolest spot of the rocket stove right below the air intake. Like Glen said,  the hottest part would be the later part of the burn tunnel and lower riser. So I was thinking that stainless drum would be cooled enough by the incoming downdraft air that it would not get super heated like below it. I like Glen's grate idea but it seems like it might only work at first but then get clogged with smaller particles and cinders after not too long. I cannot really understand it without a pic though. I'm not sure if it would allow for a downdraft design either.

What would happen if I made the burn chamber large enough to hold a filled trash bag ( with or without using the stainless dryer drum), but made the burn chamber and riser a lot smaller in diameter than my plan? That would be much easier to build and also might prevent it from becoming ridicouslouly hot ...but would it still be able to burn up all the smoke up so its smokeless?

I would really like to make something that I can  Just through whole trash bag without opening  them up and dealing with a big mess. Also , since I live in hawaii, most of the trash is not very dry. I could possibly make a plastic hoop house to use as a solar dryer if absolutely necessary, but I'd really rather not have to dump all my trash out and deal with that mess. Thank you Phil for that info about certain furnaces actually needing wet feedstock to prevent overheating ...I did not know that. So I guess it's possible to make one that handles wet trash.

Glen said "What would be the minimum common size of items in the load? Spacing to hold most of those up would allow good flow around the load"

Most of the stuff is not large ( like plastic meat trays , wrappers, etc. But like I said I do not want to have dump everything out. Does it really need airflow around everything all at once? If I put a whole 30 gal filled trash bag in, the outside parts would get the air first and burn, but the inside would just get hot and smoke and make flammable producer gas which I'm hoping would all just burn up in the burn tunnel. I don't care if it all burns up really fast. I just want it to burn cleanly in the end with little smoke. I don't care if it takes all day to burn up 1 filled trash bag  ( though I know it probably won't take that long).

I also have plenty of solar electric power here so if the design I make has insufficient airflow, I could put in an adjustable blower to make an ideal airflow. I thought that also might allow me to use a smaller size burn tunnel and riser. And if my trash is especially wet, I could turn the blower up higher ( and lower if dry).

"Do you have a good quantity of wood or other easily combustible material to sustain the incineration of more problematic or erratic materials? You would want a good clean hot burn going before introducing plastics"

Thank you, yes I have plenty of good coppice wood ( strawberry guava) so that shouldn't be a problem.

Btw, the rock I have here to work with is volcanic porous basalt. Its melts at 1200 c I believe. Its also a bit insulating I assume just because of the many small holes. I'm planning on using store bought refractory mortar but then I want to line the inside with a refractory also ....sodium silicate ( waterglass) made from kitty litter and lye .

I attached another diagram with a modified design like I just talked about. I don't know if it will work good or not. Its got a removable lid with a hole the same size as the new smaller size burn tunnel .And also a blower if necessary. To sum my goa!s again : throw in full 30 gal bag if mainly plastic trash not fully dry and make it disappear with little smoke (I also have plenty of wood to help)

Thanks again for the helpful input!
Pete

Hello,
This is my first post here. I live off grid in Hawaii and I am currently very motivated to make a large rocket incinerator . I attached a rough basic drawing. I am partially inspired by the one at the
SECMOL campus. ( https://www.linkedin.com/pulse/low-cost-high-temperature-waste-disposal-incinerator-prototype-rohit )

Mine is a bit different. I couldn't find the size of one at SECMOL but I think it seems a bit smaller than my planned one.

I have an idea they may simp!ify things . It does not have a closed trash opening with a separate air opening. The trash and air enter from the same vertical end . I have a stainless drum from a washing machine with extra holes in the end and I want to use that as a"fire grate" and to put the trash in. Those drums already make cleaner fires on their own because so much air gets in.

So I was thinking the feed chamber could be a few inches larger in diameter than the stainless drum. That would allow a huge air space around the drum with no trash clogging the airway. If done right, It seems to me this would eliminate the need for secondary air pipes like the SECMOL one needed to burn cleanly. It would also not need a cover over the burn chamber( except maybe while starting it or when it cools.)

I have many porous volcanic rock here to build it with of all sizes. Im not sure yet the best way to make it. I was thinking about making forms with rolls of chicken wire to help lay the stone around to make if easier to make uniform. I read commercial refractory mortar is probably my best bet for mortar, but I wanted ask people here since I do not have much experience making these. Then to make it insulated and reflect heat back, I am planning on putting on a coating of waterglass mixed with some perlite. Or is there better ways?

I just am not sure about the best dimensions. I read about the 1:2:3 general rule, but I  cannot seem to find info on the comparative diameter of the feed,  burn chamber, and riser. I have been assuming they are best being the same diameter, but is that rigbt?
I have people say " its not rocket science" but when I'm making some huge labor intensive incinerator, I dont want to guess at things. There must be an ideal size of the burn chamber and riser for this application. An incinerator does not need to conserve fuel, but just the opposite. And it needs to burn hot and clean. The rise is 14 feet tall, so that's the biggest challenge. I was thinking about just using a few of stove pipes side by side.
Should their square inch area be the same as the area of the horizontal burn chamber?
I don't understand what happens if its smaller ( like if I used just one or two stovepipes). Is that really bad? Or could it be better if it slows things down so the exhaust gases get to sit there a bit longer and get hotter and burn cleaner ( as long as it does not restrict oxygen too much)?

My stainless steel washing drum is 22" in diameter and 14" tall. So I was thinking the feed tube would be about 28" inner diameter. That would allow a 3 " wide gap all around the drum for airflow. That's just a guess though. I know there is a " best" air to fuel area ratio for the inlet. I dont think extra air injector pipes are needed if enough air gets in. I know the Demontfort incinerators have a secondary burn chamber that gets all the 02 it needs just from the intake, so I know it is possible.

If anyone could help me with the size if the riser and horizontal burn chamber, it would be much appreciated.

I would really like to know the opinion of people more experienced in this area even if they think its not a good idea.

Aloha
Pete