Double walled steel drum

[robin]

I'm very new to rocket stoves. I inquired with a local auto mechanic about where to find a 55 gallon steel drum and he offered me 2 choices - single or double walled. Could anybody offer me some input on the implications of the added insulation in the outer barrel? Obviously the heat won't radiate as easily from the barrel itself, but is that better or worse with respect to clean burning/efficiency? My priority is heating the home, but would also like to cook with it sometimes.

Any thought?

[peterberg]

Oct 31, 2012 17:24:54 GMT -8 robin said:

I'm very new to rocket stoves. I inquired with a local auto mechanic about where to find a 55 gallon steel drum and he offered me 2 choices - single or double walled. Could anybody offer me some input on the implications of the added insulation in the outer barrel?

Hi Robin, welcome to the boards.
A double walled barrel would radiate less heat around in the living room, but there's another important effect. The 'drive' of the rocket is caused by the temperature difference between the inside of the riser and the space around it. A double walled barrel wouldn't extract less heat, so the temperature difference will be not as large.
This will affect the speed of the gases, so it's better to use a single walled barrel.

[lolailando]

the mechanic maybe referring to thicker steel...I have never seen double walls drums,
but there is at least two thicknes for the drums, you will notice by the weight.

[thirdchimp]

Hi; I'm also a newbie. Having considered a masonry stove for a long time, I am intrigued by the rocket, might be better for me. My question is why use a steel drum as the radiative section ? Why not expose the gases to a thermal mass from that point until they exit. My thought is the drum will radiate the heat much more quickly than a thermal mass would, and might be very hot to the touch.

[kirkerik]

Welcome! ;D there is a great deal of inspiring information here! Here is a quick answer on the drum:

A steel drum can have some advantages over masonry. One can cook on it or heat water. It will heat a room quickly from cold to nice and cozy in minutes. (quicker response time) It is inexpensive and readily available. It is being re-used as opposed to recycled or trashed. It serves to cool the very hot gases from the heat riser creating a greater temperature differential to increase velocity through the stove.

It can be very hot to the touch, but can be lightly insulated to be safe to the touch and retain the quick heat on top. A heater can be built with nearly all masonry and if you look further you may find one like here: donkey32.proboards.com/index.cgi?board=experiment&action=display&thread=40

[thirdchimp]

Thanks ! - and also for the link - that is a fascinating approach.