brand New Stu. new member

With burner you mean nozzles?

If so, a word of warning. Generaly its best to stay away from stainless in the hearth itself. It actualy has a lower melting point thain carbon steel and much lower heat conductivity so the tips will ruin faster. Best by far is high carbon steel, ideal material are deep hole rock drillbits.

Edit: best out of the more “clasical” kinda materials. Tungsten and other exotic things are a nother story

9 Likes

Sorry for looking like a smartass, but l think you found out by now most if not all members here only try to help with experiances and prevrnting headakes.

This sayd, your flower pot idea is interesting but it might cause problems. In this area the heat is in the clay melting zone. But thats not the biggest problem, slag will love to cling on to it and when you try to extract slag peaces lm afraid it might shatter the pot.
Good news is the gasifier will work as is even without the pot. Ash will bind together over time to form a “pot” for you, tha ashcone. It is self repairing too. Anyway, will be interesting to see how the pot performs.

Since you bit the bullet and went straight to the downdraft, you now dont realy need a water drip. You can add the water directly to your charcoal, about 15% by weight. This will be self metering, cool the reaction, give you hydrogen and eliminate dust when handling fuel. Generaly water injecion is only used in updrafts since there the charcoal must de as dry as possible.

16 Likes

Save yourself a lot of hassle and thoroughly test for any possible air leaks. Even the smallest will stop you from making useable gas. Also the things Kristijan said. Nice looking work.

10 Likes

Stu,
Looking forward to the testing! Yes, that clay pot may give an interesting result, Try it and see! Good news is they are cheap, and can be nested to give more layers. Use lots of ash around it, who knows? :cowboy_hat_face: We can take bets on how long the label stays on the bean can. I approve!

12 Likes

Thanks everyone- I dont know how to “quote” people or do multiple quotes yet but I appreciate all those above comments. Ive been making my own refactory cement for rocket stoves using pumice, woodash and plaster. Ill pack that around the pot and yes I wondered about stacking them. - Im quite prepared for burned up nozzles- Ive got 3 forges… My main Idea is that parts are serviceable without having to get the grinder out. Kristijan - thanks for making me aware that I got it wrong about the water injection. that makes things simpler.
Its 5 am - Im off to pick mushrooms and go to the farmers market for the day. I live in the future- It’s Saturday here.

16 Likes

When you get around to it tell us us about your forges and whatever blacksmithing you do. We here like all that kind of thing.
A thread for blacksmiths by Jesse North

6 Likes

Well Its looking real interesting cant wait to see it ready to run .
roll on Thursday .
I give the label 30 seconds after first lit , for the Woolies home brand label , had it been Heinz then maybe 45 seconds too burn up :grin:
Dave

9 Likes

A quick update: Easter weekend is done and dusted here- I live in the future remember?
Im now waiting on courier deliveries for furnace fan, pipe fittings, ball valves, exhaust pipe bends.

This coming week will be a flurry of activity in the stovery. There’s all the plumbing to do, then insulate the reactor, wire up the fan and the pyrometers. then wheel it outside for a burn.
I have to figure out how to get the drive to the wheels



15 Likes

Looking at your setup. After your gases are cooled they will go into the plastic 5 gallon filter bucket. Correct? It is possible the gasifier might get hot on the lower part of the barrel. I would put some insulation between the two. Or move the filter away from being to close. You do not want any plastic melting on your first run.

6 Likes

Hmmm… I was more worried about the tyres going pop. ive been surprised at the whole concept of using plastic pipe on the cool side. but ive watched many vids of builders pointing infra red thermometers at things. if I lose the plastic one ill double down on the stainless steel buckets. the whole idea is to see if i can keep it on this tiny footprint.

4 Likes

I am not the downdraft expert here on small systems , i know many have run downdraft with great results and so i can only speak of my experience , using the same size drum as you have Stuie my output gas was way way too hot , the very bottom of the drum was hot and the pipe work temps just kept getting hotter and hotter the longer i ran way over a 100 degs C .
Now this was full on power not flaring or running a real small generator , this was running a 8kva inverter generator to get the max output for battery charging ,this system only managed around 2 hours run time before i had to refill , i had been spoilt running a updraft for many years at 4 too 5 hours run time in the past .

Maybe change out your trolley tyres for solids then no pop but maybe a sticky gooey sorta mess when moved .
Dave

7 Likes

Ive been looking at the space down there- There is 150mm clearance and Ive got bolted brackets that I can hang a heat shield off so Ill do that. It’s interesting that you say a larger feedstock mass keeps it cooler- I see now how that would work. My first cook wont be to make gas - It will be to set the hi temp paint and learn about temperatures and check safety. . If it all looks good Ill feed it a belly full of charcoal and turn up the fan
One lil thing that concerned me is that Im seeing people running non return valves on their air intake on down draughts. are blow backs a thing with charcoal?

3 Likes

Welcome to the community!

7 Likes

Oh!- I meant to say- Ive built small wood stoves for 25 years here is a link to Pinterest showing some customers installations in Tiny Homes, boats house trucks, buses https://www.pinterest.nz/blazing_stoves/tiny-woodfires-by-blazing-stoves-of-new-zealand/

And here is a video showing how I make my most popular stove https://youtu.be/b-zlTdyPLa8?si=uvkZp127BWc4S66r

7 Likes

You can just throw in a 2-3cm thick lair of mineral insulation pannel (the hard ones) and you are done. The bottom will be touchable. I did this a couple of times.
That wuld be on the floor of the reactor, the ash compartment.

Well reduced and dry gas realy hasnt got much heat capacity. It cools quite fast.

In my experiances hopper puffs only happen when charcoal level is extremely low and the lid is leaking. Other thain that, it never happens.
Oh, but an unsealing lid can cause the glowzone to rise up and up towards the lid so thats something wery important to prevent.

Also, if you use wettened charcoal l find there is no need for any kind of intake valve. At shutdown the tiny amount of steam will create a positive oressure that pushes aginst the air.

9 Likes

They can be a thing, it just depends on all sorts of circumstances and design choices. My pipe gasifier puffs bits of burning stuff out of the nozzle at very low engine speeds.
Rindert
DSCN3250

5 Likes

Any more than a pet dragon belch? I could cope with that.
edit- By the way that is super simplistic! does the cyclone pick up much?

4 Likes

Yup partly why my water injector is made the way it is. Its a flash back arrestor. It unscrews so that you can easily clean it out if that ever happens.

Putting a check valve maybe a bad idea unless your puff back lid is working good.

5 Likes

I have two little burn holes in a pants leg. I am always warning people not to put their face down there, and don’t watch the fire in there.
Rindert

5 Likes

Ouch! Im changing pipework supplier. some of these are 300% more expensive than the wee local farm supply shop

4 Likes