preheating a brick oven with a rocket stove concept

Hi, I have been pondering on how to preheat my enormous brick oven I built in my garden. Obviously I could just stuff it full of wood and light it. But this isnt ecconomical for a couple of loaves of a handful of pizzas for friends. As it takes around four hours to soak heat into the brickwork. That means a lot of wood. Having seen the rocket stoves on youtube, I wondered if it would serve as a preheating system. As usual I over-complicated things and started to work on a design for an elaborate heater. Then I had a revelation over a cup of coffee while staring at my brick structure.... make a rocket stove out of wood and insert it into the oven!
I used 4 pieces of 2x2x24 and a piece of steel plate. Two of the pieces of 24" wood layed at the base about 2" apart. Then cut the other two pices into 6" and 2" pieces to make a tower at one end. This was inserted into the oven, lit and steel plate bridges accross the long pieces to serve as the air tube. This burned quite happily for 1 1/2 hrs before collapsing on itself. By which time the oven temp had crept upto 170C on the roof,120C on the back and sides and 100C on the floor. Not hot enough for cooking yet but put heat into the brickwork cheaply. A full test will be required soon to get it up to working temperature. Hopefully I'll save myself a few logs each time using this little idea.
I'll add a photo when I find out how to.

great idea try looking at the blast furnaces or wood furnaces same principle but they use coal or coke on top highers the temp even more some pics and vids are on here may throw some more ideas your way

also try making a j tube with the bricks a loading area but add secondary air should get more of a blast of heat in the channel

I have made a small one by feeding a brick L rocket into a brick oven. It works. Doesn't take much time to heat up.

Try your idea with light firebrick. You may have to keep the brick together by tying them with wire (see Pekka's videos). It may work better than the wood. Just an idea I am throwing out there.

I did consider the fire-brick route but decided it would be too much messing about each time. The wooden version just becomes part of the bigger fire prior to cooking. I have been looking into forced air rocket stoves to fire a jet of flame into the oven space. That could possibly sit in the doorway to the oven vault and simply be lifted off the fire-up fully. I saw some old pamphlets advertising gas lances as a new way to heat old wood fired ovens. Thinking along those lines to throw heat in rapidly and cheaply but using wood or wood-gas not propane gas.

Swedish candle?   

Basically LOL.
I was just trying to get more intense heat into it from a small quantity of wood before full firing. Otherwise it works out to be a quite expensive folly in the garden.

The wooden rocket stove shape burnt quite nicely. Needs forced air next time to "pimp it up" a bit though.

I have also given this idea some thought and if you have read any of my prior post...my friends own a brick oven pizza joint and it uses more white elm and oak than three large houses in a year...and worse than that..when we built the joint we didn't allow for outside feed which means wood comes in through the kitchen..hence "right up the chimney". I'm not against forced air but think there is a trade off as far as energy for running and fuel being spent faster. Also, this subject matter is one I like as it is cheap and easy to experiment with and if your cooking anyway, it even makes more sence and cents.

Deep mdown I knew it wouldnt be a cost effective oven unless I cooked loads of bread and pizzas etc in a day. My wife would start saying "where are we going to put it all!!!!" . So with occaisional use I can justify (kind of) the expense of heating it up. Although if I can find a means of preheating it cheaply to reduce the amount of wood for the main firing, then that be a bonus. One of my workmates is a retained fireman. He said initially the fire in my brick oven will just soak up the heat. Effectively cooling the oven space and making the burn "rich". Once the brickwork is hot, it then allows the fire to burn hotter and therefore more efficiently. So, If a I can preheat it externally first with a high efficiency flame and a small volume of wood. That should do the trick.

this one is the no 8 but ive never seen it lit



before this gives chimney view of rs underneath

One of those isn't using a door. That makes a big difference. I always enclose my brick ovens, otherwise you are only allowing the heat to escape. The purpose of clay is to cook with radiant heat.

Thanks for the vids. The priciple on them is similar to a bread oven video I watched recently where the fire was under the hearth and fired the oven through a hole which they capped to direct the flames around the oven compartment before firing the dome directly with it. As my oven is already built I cant change the firing chamber now though. Initial research suggested the easiest method was the standard fire in the oven vault concept. I think they based it on living in or near a forest though. lol

heres another way much hotter



with wood

youtube.com/watch?v=UHdrdfG8nY4

Hmmmmm..... multifunction preheater ;-)

i do know that the much smaller rs stoves use a 17-19" vortex pipe in them but we dont know how high your ceiling height is in the pizza oven is using trying2hards turbo rocket maybe what you can use if your ceiling height is at 18 1/2" or 19" as using the heat of those systems which ever you choose to build will take the temperature high all depends on you conserving wood or not

Open systems would be very little help for me... they just aren't efficeint..correct me if I'm wrong. I also know that they have to be open for some applications, but not for knives or pizza.

vault height 16" and the door way is 10" high. Apparently this is an optimum size for heat retention and air flow. So I built it to those criteria.

right then t2h is 17" high minus his burn box 0f 5 3/4"



as long as you have 12" or more above your burn box a rocket performs well enough these systems work well as they have a small diameter of external flue area

a burn box of yours has to be either 2-3" as burn box can be elongated the top must have a distance of space 1 1/2" or 2" at the top

as ive never seen t2h with full bore burn and top open heres my uploaded vid

edited video no longer exists

that box is 4 3/4" and total height is 17" from the bottom

what i can tell you if you covered the top over with just a 12" wide gas bottle and a 9" box the fire would kill itself t2h way maybe the best

so as a suggestion id be looking at 4"x 4" box going into a 2" x 4" and then up via either a vortex or old style fire up an elongated style of rs stove

to save cost build it in steel first and make sure it works after that build it in 2mm or 3mm stainless steel