Idea for burning wood chips

Hi

I had an idea watching a topic here regarding burning pellets in a rocket mass heater (https://permies.com/t/18515/rocket-stoves/Burning-Pellets-Rocket-Mass-Heater).

I'm attaching a sketch (done with my exceptionally excellent drawing skills) to see if somebody can validate it, improve it, use it, or discard it as a stupid idea.

Basically, this is to help reduce the volume of sticks burning, not to replace them. To use free fuel, if you will.

You create a tunnel on the right (or left) of the traditional burn feed to serve as wood chip hopper and fill it with wood chips in full. There is an airtight cap on top, so no air is allowed in. The cap in the middle has a piston (as engine pistons), that serves to agitate the chips if they stop falling down. The proportion between the tunnel size and wood chips size determines also the amount of attention needed to make this work. Maybe the chips will fall down nicely, maybe not, who knows.

The tunnel is not necessary steel or iron, it can be permanent with refractory, the size also is a variable.

Just an idea.

This video gave me the idea to make one from 6"x6"x1/4" square tube. Wood chips are free in my area and with a little care to get them properly dried out "so they don't start to rot", free"ish" fuel?
https://www.youtube.com/watch?v=dtZaOLYuehA
My first try was inserting a smaller section of stove pipe into the feed pipe in my pocket rocket and it worked kinda sorta after I got the feed tube height dialed in. What I learned from that first try was that the feed tube needs to be smooth inside and VERTICAL. Also with the chips just falling out of the tube as they burned, the fire would smother itself a bit before it got going again.
My second one was built like the one in the video except the heat riser was was made from the tried and true fire brick wrapped in 1" ceramic wool insulation, even tho I could have made the heat riser out of 1/4" square tube it would still burn out and I would be afraid to insulate it for fear of melting.
The basket is a must, it keeps the opening for air to enter at a constant. In the video it looks like a stainless fryer basket, I made mine from 1/8" stainless round bar.

Blendi Kraja : Same Author / Builder, different Video See link below :


https://www.youtube.com/watch?v=E9JbbzlxBH0&index=9&list=PLtIuZ9K-UzcNnCmoKicRLzYQndplSkUuR

Rob T. is still running his pellet Stove as the primary heater, and has a secondary wood stoves that (I Think ) he runs only as supplemental heat

while he is in the green house !

I believe his wood chip trials actually proved to be too labor /energy intensive for his situation - but you may have much better luck !

For the good of the Crafts ! Big AL

a hopper with chips- auger fed into the burn chamber controlled by a thermostat- temp drops- auger activates- feeds more fuel- or just calculate the feed rate, and set auger to work at that speed. power for the auger and thermostat etc ? thermo electric generator
cheers
wayne

Here's a rough video I made a few years back of a prototype wood chip burning rocket stove:



There's an older thread with a little discussion on it here.

Good luck with your stove, I'd love to see some pictures or videos when you get it built!

Hi to all

This thread has derailed. I would like a discussion of my idea, is it viable, I didn't intend to find the most convenient way to burn wood chips in a rocket. There might be, and of course there are.

I had in mind a solid rocket that burns sticks and this "side-chamber" with wood chips, that you can use if you have chips or just keep it shut if not. You know, kind of a module if you will. The rocket has to work as such, and the module can be added or not, if yes used or not. But I would like to know if it is a good idea in itself. I think there are a lot of people that might have access to free wood chips, and really pass the winter with 1/10 of wood quantity advertised for the RMHs.

Best.

Blendi

sorry mate- didnt mean to detract from your thread. i thought you were looking for solutions to using wood chips- and your drawing was just one proposal- apologies!
on your design though- is the "magazine" going to be loaded only once- or will be continually fed from a hopper( i guess with the air tight seal then it will be a single load.
i am totally new to this whole rocket stove concept- so please forgive my ignorance on the topic- but would it not just be easier to build the fire using a kindling starter- then a wood chip mass fuel-as apposed to conventional firewood. would that not achieve the desired effect- or is the magazine that big that you are trying to achieve a sustained burn.
cheers mate
wayne

Blendi Kraja : Thank you for the additional clarification ! I see some problems with your Feed stock and your design. Plese note that after 20+ years of a more

or less static design, multiple changes have /are happening, and we are All open to ''Think Outside the Box " Efforts.

I for one like wood chips as bio-fuel for large fluid bed Power station/heating plants, But I Believe that in an effort to be more Sustainable the Ramial mass,

the high nitrogen content, the leaves, twigs, and branches are best recycled back into the ground !


I am sure in your present location you are familiar with Coppice-ing and Pollard-ing. With most of the wooden fuel in the 10cm to 20cm range the amount of handling,

labor and use of power equipment Increases rather than Decreases the amount of inputs and missed recycling opportunities /Sustainability!


We will have to discuss a little history to be fair to your design!

A ) One of the best points of a Rocket Mass Heater RMH of the traditional Vertically fed J-bend type is its ability to be easily fed over a short 1hour period and

the having 12-24 hours of Heat Energy Stored within its thermal mass! Truly it is this constantly radiated Heat Energy without the further wood burning of big box

wood stoves that provides the 10 Xs wood fuel savings . Only in Extreme cold climates, or Attempting to heat too large an area with too little of a Rocket are long

burns truly needed !

The horizontally loaded and fired L Batch box style allows for a single larger fuel load that can be burned faster, this can reduce the size of the entire unit.

Depending on Build specifications this can give more prompt heat, or slowly released heat through one or more bells .

Each model has different combustion core area characteristics to cleanly combust their wood gases!


Your wish for a RMH that could be started on sticks and then converted to wood chunks would seem to require Two differently designed Combustion areas for burning

the two different materials. I am afraid that any type of compromise combustion chamber would be just that -a compromise !


I Think that this will add greatly to the complexity of designs that are loved for their simplicity .

This is also how I feel about a mechanical wood chip delivery system, too complicated and creating additional wear and tear on the Fuel Feed Area .

As I stated before " Wood chip trials actually proved to be too Labor /Energy intensive " ( though you may have better luck )

-it is also possible that I have again totally missed your goals ! For the good of the Crafts ! Big AL

Hi Allen

Well in truth I hadn't any specific goal, just an idea came to me and I sad why not.

Thanks for the explanation.

Best regards

Blendi