Rocket stove powered oven.

[gumacanian]

A couple of years ago I built a traditional fire brick pizza oven...It worked fine but took 1/2 a forest and 2 good hours to get the bricks to turn white..No problem if I wanted a big pizza party with loads of guests etc but a bit much for one or two pizzas..
I had and old German electric commercial oven in the yard and I wondered about hooking a homemade rocket stove to it via the bottom of the oven..
Anyway..Build is half done and I fired the thing up today.. It looks very rough but it seems to work real good with a heat up time of only 15 mins!! I guess I can make it look prettier by cladding the hole thing in red brick..
Once the mould was in I filled the gaps in with perlite and cement..
Today`s fire up was really to burn out any old electric wires and the rubber door seal...Eventually that all went away and everything went smokeless..
After checking the vid below...Any guesses roughly the temp inside? I threw in a piece of 2X2 and it combusted into flames pretty quick..
Cheers!

https://youtu.be/oV44b-ux1ig

[gumacanian]

At what temperature does wood ignite?
A:
QUICK ANSWER
The minimum temperature needed to ignite wood is 180 degrees Celsius or 356 degrees Fahrenheit. The amount of time of exposure varies due to the type of wood. Long-leaf wood has the fastest ignition time at this temperature, taking about 14 minutes to ignite.
(I threw in a hardwood..Gmelina)
For a wood ignition time of less than one minute, the wood must be heated to a temperature of 430 degrees Celsius or 806 degrees Fahrenheit. According to the U.S. Department of Agriculture, studies on wood ignition conclude that there is not a fixed temperature for ignition, and the moment of ignition largely depends on the amount of exposure time, the density of the wood and the type of wood.

That lump of 2X2 hardwood Gmilina was only in there for 52 secs before I opened the door..
I estimate that oven being between 800 and .........Too hot for a Pizza probably.

[david s]

2.1 SOLIDS 2.1.1 VARIOUS MATERIALS

Reactions to temperature exposure
Reaction	Temperature (Celsius)
Wood slowly chars*	120°-150°
Decayed wood ignites	150°
Ignition temp of various woods	190°-260°
Paper yellows	150°
Paper ignites	218°-246°
Oil soaked lagging ignites	190°-220°
Leather ignites	212°
Hay ignites	172°
Coal ignites	400°-500°
* wood chars at a rate of approximately 30-50 mm/hour

Here's a useful site

http://www.tcforensic.com.au/docs/article10.html

[Tim_FB]

At what temperature does wood ignite?
A:
QUICK ANSWER
The minimum temperature needed to ignite wood is 180 degrees Celsius or 356 degrees Fahrenheit. The amount of time of exposure varies due to the type of wood. Long-leaf wood has the fastest ignition time at this temperature, taking about 14 minutes to ignite.
(I threw in a hardwood..Gmelina)
For a wood ignition time of less than one minute, the wood must be heated to a temperature of 430 degrees Celsius or 806 degrees Fahrenheit. According to the U.S. Department of Agriculture, studies on wood ignition conclude that there is not a fixed temperature for ignition, and the moment of ignition largely depends on the amount of exposure time, the density of the wood and the type of wood.

That lump of 2X2 hardwood Gmilina was only in there for 52 secs before I opened the door..
I estimate that oven being between 800 and .........Too hot for a Pizza probably.

I would add a couple thoughts to the last post. Moisture levels play into it as well.

From what we have seen, wood can combust between 374 and 500 degrees Fahrenheit. We tested this in our dual gas oven models to see how hot the chamber got before ignition (we used oak).

Here is a page we wrote and a great link to Utah State University forestry chart.

[gumacanian]

I would add a couple thoughts to the last post. Moisture levels play into it as well.

From what we have seen, wood can combust between 374 and 500 degrees Fahrenheit. We tested this in our dual gas oven models to see how hot the chamber got before ignition (we used oak).

Here is a page we wrote and a great link to Utah State University forestry chart.

Thanks...Can you remember how long the oak was exposed at those temps before ignition??

[gumacanian]

Did three large pizza`s last week... This oven performed about the same as my brick dome oven with white hot bricks....1 minute cook with a small fraction of the wood used..
I put a piece of 2x2 hardwood in the bottom for smoke..
Incredibly powerful little oven!