First firing of my completed rocket heater with muses ponderings and other babble

Well I fired 'er up today with help from my trustee accomplices.

I was able to do some editing with windows live but what you see is what you get.
Sorry for any expletives from onlookers, forgive the barking dog "Penny the catahoula"  was on a threatening chipmunk.

On a more serious note , after the crowds abated  I sat tending the fire  and trying things.

With the door open I fed finger diameter hardwood sticks . got the temp at the "hot spot up to 920 F.
Heat on hot point was up to 700 plus F ( cant remember exactly).

Thanks for watching , hope I did not drag on too much,  any  questions ,suggestions, comments  on the stove are welcome.

Stove test

i have to say nice build

also nice to see some new stuff being tested out on there builds

i have to admit getting rs started is some fun in doing so as ive been testing

the thing i found out is shove some paper instead of cardboard a bit further back and put some light shim sticks on back as adds to the lighting better

with door i found its best to leave it open but i could be wrong once i get the top on it as thats what ive noticed with ppottys and t2h systems they always light it and leave door open until it gets going properly then load it up and close door

also a suggestion with yours being long on burn box try pushing the wood deeper inside the system i suspect it would light up much better at prelight stage

also ive made this mistake overloading it at start of the lighting process i should have used light shims of wood to get it going much quicker

i think alot of us make this mistake when first lighting there system

Gadily:
Will try a few different things that you suggested.  Decided to enlarge the hole where the screen fits in on top of the ash/air intake box. Going to be 2x the original area. Then I'll modify right hand draft control.
I wonder if there is some formula for fire box area / volume vs. air intake area , some sort of rule of thumb ratio   

By the way even though the fire box is long, part of that space is taken up by the air intake . I try not to place my wood on it. If I shove the wood in way too deep I risk choking of the riser/vortex tube.
It is definitely a learning curve.

I just think it would be neat to hear that rocket with the door closed  

Just to clarify the second "hot spot" referred to in my post was 700 + deg F on the heat exchanger cap ring.

Thanks

Bill

the only start up of t2h on video i can find he uses a propane torch to light it

view from 8 mins



ive never seen from a first fire up other than edited editions

ppottys start up





oh and we all make mistakes lighting them but if you notice its fine shimmings of wood to light it with paper on first lighting

i found with my building it was best to use paper at the back with light shims to aid it then in middle light shims but more of in light shims on bottom then criss cross paterns as the fire lights up the paper soon goes so the wood drops down to the metal and dosnt block the riser vortex area

ive also done some tests but these are with steel box section swg 16

https://woodstoves.forumotion.co.uk/t62p15-secondary-air

with 3mm secondary air i seemed to lose it however i have got it back by extending away from the burn tube but i have the large burn box on front of my build

dont laugh lol

tried tonight to get a start up video without the cap on rocket stove

had next doors kids join me as wanting to know what im doing so came to watch passed camera phone to them did the start up filling stove with paper and doing as i said above with the wood loverly draw on it

got it going and wasnt they surprised on how hot it got fast as id explained what it does including the vortex action proceeded with placing cap on and it went up the chimney flue pipe drawing on it

got some back drafts they left before this now tested it out i found out the pipe up the garden was stalling it out why i dont know and causing backdrafts with wind

ended up cutting 6 ft off flue pipe and doing a straught up what a difference to the system had loverly draw on firebox and also pulled in all the fire gas included had it roaring loverly even with normal glass seal on it

what an idiot i feel for not realizing i need a straight up chimney pipe makes all the difference when testing a sealed system

video failed which is a shame or you would have seen and heard the convo on the video even with people asking about the system and being shown how it works and then also asking further questions makes making these all the worth while in doing them

will try again soon to get the video done

Gadily:

If at first you don't succeed and all that. Maybe also throw  Murphy's law.  
I can not help but wonder how my stove will perform once  it is hooked up to a 24 foot high 8" diameter chimney?   Might be intense. I definitely want to construct a "wind deflector " like tryin2hard uses.
Anyway I look forward to your next video. Work safely 

Bill

Your existing chimney is going to add more draw to the stove and that is a good thing to light it. If draft is too intense, you can always add a dumper to the chimney.
I am not certain about the relation between primary air intake and stove section area, but I suspect that this relation has to be around 1:3 or 1:2. I usually make air intake big , I can always regulate the amount of air with a valve...

Caotropheus:

I definitely will use a flue damper as I always have with conventional wood stoves. I do see lots of installations omitting this on "air tight" stoves. As trying 2hard pointed out in a video it is a matter of safety. (and extra control)
Thanks for the ratios . I am in the process of increasing air intake by the addition of another intake on the front of my ash/air box.

Bill

hi bill how are you progressing with this build

ive taken a pic below and to me id say that was over stacked with wood ive made this mistake myself when first lighting up



may i ask you how long your tube length is as looks to be 6" or 8" box section and what sort of vortex method are you using and size of vortex tube what is the space between the cap and vortex tube

as goes for secondary air feed i used 3mm stainless steel 1 1/4" i found it will do the sound but i had lost the sound while using it

with yours the rocket sound will come back when you open the door, close it and the sound appears to disappear

with mine i took it away from any heat source

pic1 still no visible sound unless door open


pic2


with this one via ppottys build i get full sound of the rocket at full burn just by making the secondary air pipe much colder with the door shut not forgetting ppottys system forces air into the system by convection process

Gadily et all:

Have not done too much lately, visiting my kids/grandkids, entertaining visitors and of course doing some fishing (a man's gotta do what a man's gotta do)  

I enlarged the ash box draft hole about double it size, added another draft hole port on front of the ash box, modified the draft on the left to the "bolt style" and increased it's intake area. I pretty well maximized the air intake allowed by the ash/draft box.
I've finished painting the stove.

The fire box is 8" square tubing 3/8" thick. Internal dimensions are 7 1/4" X 7 1/4".
Length is 24" not including the door. Usable length is 16" with the wood about an inch over the bottom draft port entrance. The idea is that fire wood "face" cords are cut to 16" length(more or less)

Now the vortex tube gave me "kittens" , unfurling 1/8" thick stainless is real difficult. In end I partially unfurled it (see tryin2hard vortex design ) I ended up cutting off a piece and welding it back on to form a more open entrance. I oriented the tube so 50% of the opening was blocked. I then welded o a plate to block off the left side (closed side). Secondary air is 1" id stainless ss pipe.


Some of the loss of rocket sound is do to sound being muted by the door itself blocking the noise. A more muted rocket can still be heard.

Secondary Air:
I have been thinking about the requirement for pre-heating the secondary air. The wisdom being that we do not want to cause thermal shock i.e temperature reduction and possibly heat of reaction reduction.
But do we worry about warming up O2 when added to a cutting torch?

Their is less available O2 (amount per cubic foot not %) at higher temperatures , Density of air is ~1.2754 kg/m3 at STP . That same air at 300 deg centigrade is .6159 kg/m3 . So my thinking is their is about 50% less O2 per unit volume/time. (The density  reduction rate really changes dramatically at lower temperatures  but starts levelling off above 350 C or so , in other words it is not a linear thing)

Trying2hard's latest endeavour uses direct air intake into his rocket cooker stove and it raised temps. dramatically. Caotropheus in-laws stove uses non preheated air.

So I'm no expert and I might be full of it but I'm putting it out there or is that out here! 

Wow Bill really nice job man, you worked hard!

What are the dimensions of your fresh air intake?

You could add two more air controls onto the front of your fresh air intake box, if that does not help, you may need to pull the fresh air intake box, cut a larger hole and install a larger box with double the size of your air controls.

This is what I think is keeping it from having the rocket sound, however........the rocket sound is not as important.

What is important are two things, a clean smokeless burn, and secondary burn.

I probably got the rocket sound with my air controls shut down due to the very small size of my firebox.

Ratios are important when building on the scale such as you did.

Magnificent stove man, as well I really liked your secondary air control.

It looked to me like the bolts in the primary air took up much of the space available for the primary air to make it way by them, thus possibly constricting your main air.

Man for your first fire up I would say that was a pretty good success, I could hear some disappointment in your voice, results are not always what we expect, however once we can see it in operation after observing it during several burn times, usually we can see what it needs to be tweaked.

Not much needed for yours man.

Also something to think about, I tell this to everyone who uses the black brush on stove paint.

I found that my stoves would gas off with each light up until it got to operating temps.

I hated that smell, I will no longer use that stuff!:>)

It was exciting to see your stove on the scale you did it on, those temps were pretty impressive considering a first firing and testing.

Once you do a little tweaking I am betting you will get the temps to rise, once you are sure you have secondary burn taking place, you can turn the main air controls down to almost nothing.

I think due to the scale of the stoves like yours, ppotty's, Gadily's and others you guys are entering into an area where scale ability on ratios become a real issue.

Honestly, the rocket sound is exciting for the first time of your stove ignition, but after much experimentation and research that is what it should not really be about.

It should be about optimum btu production and efficiency with as little possible of smoke and particulate emissions.

Thanks for sharing your build, that really was a treat to see.

8" x 16" tube should be fine with a 7" x 1 - 1 1/2 primary air did you preline the sides with ss sheet

now ppottys and mine is 13" + 9" total 22" + 2" long tube however we preheat our primary air via the convections at the sides force air into the fire box in doing so we force the air down the tube therefore aiding the vortex suction at the vortex pipe

with yours id try a plate underneath to the air intake dont weld it as a suggestion it may make a difference

my reference with air and water is when heated air and water expand so the colder the air the more it expands in the secondary air

all my tests are done with the burnbox at 13" + 2" for the vortex pipe the secondary air i first tested with was 1" box section swg 16 i think so 1-1,1/2mm thickness i opted to use 3mm ss tube 1,1/2" but wished id used 1,1/4" or less box section in ss tube

4", 5" or 6" tube for the vortex but i would have suggested using the 5" or 6" for the size of your burn tube as you dont say the size of vortex tube

its part of my reason for asking as i noted there response on there first burn but saying that a goodish burn at that rate

Tryin2hard, Gadily et all:
I appreciate the encouraging comments, and thank you for them.

Riser tube is 4"  x 1/8 ". I would have preferred larger but the only stainless tube I could find at the local scrap dealer was this diameter, $2.00 a lb. too I might add . ( sells stainless for 2 bucks and buys it for 40 cents - not a bad profit margin). (mild steel is a 6 cents in  & 40 cents out)

Total air box area for draft is now modified to max at ~ 12 sq in. .I've modified an existing draft and added a third intake. So that's 3 x a 2" dia  =~ 12 sq in. (restriction of bolts = some for sure).
Vents are 1 left , 1 right and 1 front of air box.
I am reluctant to  add a larger airbox as it will cut into my useable burn area. I however may , if necessary, add additional intake to the front sides of the stove and or the door below glass.
It remains to be seen as I'm going to run another test  burn.
It seems that my "cruising " temperatures are about 600 F on the stove and 500 on HX top.

My building is 26' x 32' with an 11' ceiling .Walls & ceiling are well insulated ( R24 & R40 resp.)
Big  hollow wooden door ( as seen in my videos) is a large  heat loss source.
Average winter temp ...let's say 0 degrees F( could be worse in jan)
I might easily burn 3 armloads of hardwood at ~ 30 lbs each to bring up to and maintain  70 F.
Lets call it a 10 hr day. Heating on subsequent  days is a bit easier  but not much.
Hence my desire for fuel efficiency and economy and of course a chance to mess around with fun stuff  
I'll post a vid of my next test with my mods.
Appreciate your interest.

catch ya later
Bill

Almost forgot; trying2hard how much bolt should I cut off of  my draft controls? What distance out from the closed position will give me max draft i.e an inch or less or greater?

bill ive been looking at these results and from what im reading yours is around the right mark

https://woodstoves.forumotion.co.uk/t299-rs-testing-results

in line of thinking its down to the stoves preair to the firebox needs either bigger to perform the full burn effect whilst the door is closed to the effect when the preair is reduced ( low burn )

ppottys size of bottle is roughly 15" width x 40"-44" high ppotty does preheat his preair you can do this by running a thin sheet under the burn chamber tube about 1/2" gap to the entrance at the front underneath for preair