Rocket stove project for a change.

[gaz1]

the build maybe seem alot for a wood stove but it has alot of advantages compared to a normal stove



the wood above would be gone in 3 hrs ( 1 burn )even if you built a rocket stove within a stove as i did with that model above
however same amount of wood and i get 3 burns out of the same wood thats 3 x 3hrs within a rocket stove
with 2 heat chambers putting out 1000f+ from the stove and not 1000f+ up the chimney ( like a normal wood stove ) as that only reaches 2-300f depending on your build

yes the build is lets say 1200 compared to the 590mm of depth of a normal wood stove it dosnt have to be this length though all depends on the tubes that you use it uses no fans neither electric or a stove fan and spreads the heat around the shed rather well

 

[gaz1]

so youve built your firebox and the support for your secondary burn chamber to vortex tube

now to build your heat exchanger theres a few designs for this part

a note here on heat output if you have a small shed a small rocket stove is ample enough

this 30" high rocket stove will cook you out of a 11ft length x 9ft wide 7-8ft high shed



whilst this type will heat a shop 2000 squ.ft stick built 6x2s, insulated walls 10 ft. high



a round tube like the above picture or with 3mm 1" bars to create fins on the side of it

or you can build the round part out of box tube as its your choice on welding



the easiest way is to use tubes and this depends on the size of workshop that you have the pics below is guaranteed to heat a shop size of 2000 squ.ft stick built 6x2s, insulated walls 10 ft. high insulated ceiling/roof

this model has 12, 2" x 3mm tubes


the best way to create the heat exchanger is with a seperate unit, by drill center holes in a plate to match the size that you are fitting then you can hole drill them if your not sure if you have enough of them space the holes equaly you can use 8, 10, 12 you decide on how many holes you want to use but if you need more you can fit them after a main build as you already have a hole predrilled in them

the holes that you dont use just tap them and fit bolts for the underneath part, for the top just slide over a piece of 5mm steel off cut and run it and see if you need more tubes to be inserted

 

[DennisCA]

I like that Loz fellows design, would change some things though. Use more mass as part of the design rather than optimize for rapid heating of air.

 

[gaz1]

I like that Loz fellows design, would change some things though. Use more mass as part of the design rather than optimize for rapid heating of air.

I liked the firebox of loz's for a sealed simple firebox, but i prefered the shorter in height heat exchanger of trying2hards

thats why i built a smaller version of both of there designs

theres drawbacks too both having too much mass to heat vs rapid heating of the air, its where best to use more mass, its 15mins to heat up with firebrick and a core build
whilst being smokeless to get it to a smokeless state takes about 3-5mins from lighting all stoves smoke right at the start of lighting

a firebrick or a core build is heavy thats why he dropped it when fitting the core and broke the top part the firebrick is easy enough to install into the firebox but ackward to fit into the secondary burn chamber,
thats why ive shown a bolt down version so the secondary burn chamber and vortex tube can be fitted/built easily

the heat exchanger is built seperatly as it provides better heat output whilst loz's is a simple build but its flow of air isnt enough you would need to create holes at the side so air could run through the tubes and a different top build would be needed though simple changes

 

[W.olly]

As i keep saying Gaz, i would make the best of the best but my scrap heap is limited to what is in it.

 

[gaz1]

the back box 4mm is plenty enough material for the firebox and the secondary burn tube 5mm is better though

ive already tried on my test build using 3mm stainless steel myself for the firebox as it bends and buckles and expands rather well

the orange tank is also enough if you widen it by jacking it out and filling in by pushing it out into a bigger circle

the exchange heater tank can be 2mm but 3mm like the gas bottle is best

im also posting on your post and helping anyone whos interested into building one themselves

 

[W.olly]

Got a bit more done, glad its near done as running out as materials lol

Fire box is near done, need a bigger ash pan, but once i have it up and running ill decide on that then.

Made the grate from 12mm square bar. had to bloody buy that. Aswell as got the gear needed, rope fire brick and cement etc.

I am having a Decagon tube made at work, 150mm wide, should have that done this week.

I finished today with cutting the heat exchanger down ( gas cylinder ) it now has room for a 32inch vortex tube. the melting pot will be 100mm above the top of the vortex tube.

I will be building a vortex tube this week, just waiting for some 150mm plastic ducting to arrive to help make the mould for the Perlite/cement mix i am going to do.

 

[gaz1]

you still need to come much higher in the firebox as you only need 1" - 1 1/2" it still pushes over rather well when its fully opened up


i think your doing a flat door opening make it out of angle iron and push out the rope in the middle for a much better seal

but sealing to an angle frame is much better


if you look at the door and frame you will see the method used as its a much better door seal to use

 

[gaz1]

your top center wants to be a flat plate or door that needs to be wider than the vortex tube as the heat coming off of it is very high

in the vids its shown through fireglass the dial to the right is off the scale in well over 1700F

 

[gaz1]

for those that are wondering how to follow down the secondary burn tube as i believe its a better flow than pushed in at the side right at the entrance

i first followed it with 3mm stainless steel tube the pipe top right of the pic with welded cap on it



you can create this by buying proper firebrick not the 1" stuff if you do use it the cement will fail at the joint of them and drop down as mine did, by grinding it to shape the more rounded the more heat transfer to the secondary air before it enters the vortex at the rear of the the pic

because it follows down it will aid the spin much better than been forced in at the sides if you want to use the simple way this is your choice that was my choice in the build of mine

 

[W.olly]

No angle iron left, just flat sheet and bars. all in hand for it , just not got around to it yet. I will just make the fire box door same as all the other stoves i have made, worked well enough from bar and metal strip etc.

 

[gaz1]

the users core build with failure and advice

DIY Fire brick ?

Trying to make this riser for the rocket stove. Failed first time when i used Perlite, silica sand and cement. 7/1/1 ratio. reckon i didnt leave it long enough ( 2 days ) before i moved the moulding to help dry better. That was a recipe i was given and didnt look much further until last night...

www.mig-welding.co.uk

 

[zippot]

This is my firebrick built system using mainly second hand parts, the Garage is 3 car lengths long so it has a huge mass which is about an 1/8th full at the moment. I will get better efficiency but thats a lot of material (cob ) to make with a bad back. only had it on once this year it hasn,t been cold enough yet.
I enjoy welding but as a beginner would never be able to construct anything like your builds. or afford the steel.

 

[gaz1]

@zippot
i dont know your build but if its built around the jtube build that top thin plate will get hot and can melt id advice putting over 2 firebricks over the center point of the riser if the top does fail and it can as its only 1mm its why i use 5mm or 6mm thickness at this point as im also not a lover of using the fire glass either

for showing the rocket stove to others that it works great and how it looks the fireglass is fine to use but i strongly prefer 2" worth of firebrick at that door point myself then its got 2" of fire brick that you periodically check for issues and then also its got 5mm thickness of steel to get through

its the main issue of a rocket stove that can cause real damage but its fire wood usage is one hell of an advantage
remember its 2000f going straight up to your garage roof

you will have a hard flame going straight up and there difficult to stop at least if you have some sort of back up on top it gives you a chance to view wear and tear and if it fails on you have chance to pull the burning lengths out and allow the system to die out

otherwise throwing water on them will fire pure red hot steam out of the top

 

[slim_boy_fat]

which is about an 1/8th full at the moment.

Give yourself time...