Hello from Illinois. USA

Hi everyone !

Jim from Northern Illinois.

I have always been fascinated by the operation of the return stack orchard heater.  The heater is fueled by diesel fuel or kerosene, and is capable of delivering 100,000 BTU's.  There is very little smoke if any in the exhaust during operation.  There are similarities between the rocket stove operation and the orchard heater.  Both heat gasses, and use the heated gas for draft and high temperature combustion.

I currently own an old orchard heater, and would like to experiment with it.  I would like to try to convert the fuel to wood pellets, or wood sticks.  I'm sure someone on this forum may have some tips as to go about the conversion process.

I would also like to build a rocket heater for my work shed.  The shed is 16' x 16' x 10' uninsulated, and is currently heated by a 60,000 BTU military multifuel heater.  The heater is extremely noisy during operation.  I have a couple of old LP tanks that might be the right size to build the rocket stove, but I would like to get an idea of how many BTU's/ stove size before I attempt any fabrication.  I would like the stove to be a minimum of 40,000 BTU's.

Here is what a return stack orchard heater looks like:



I look forward to meeting everyone !!

Hello Jim, welcome.
My workshop is exactly 26' x 22' x 8' concrete floor, brick built, with 2 large lexan roof lights at the rear end. No idea on the BTU output of my stove but it easily heats the whole space to over 20C in around 1 hour. I once ran it at max for 2 hours to see what temp the shop would get to and at 35C I had to close it down! Temps outside where around 4C at the time I have the only shop with no snow on the roof when it snows   

Hi,

Thanks for the welcome, and the reply to my question. I have seen your rocket heater on You Tube in operation.  That thing really got that water boiling in the tank on top.

Judging by the temperature outside, and the temperature/time rise inside, and the shop size, I am estimating a BTU output of the rocket heater of around 50,000 BTU'S at full throttle.  That's impressive !   The tanks that you are using for the heater look larger than the tanks that I have, so I will have to find larger ones for my project.

Do you think that a return stack located above the combustion inside the riser tube, returning to the bottom of the riser would raise the combustion temperature even more ?   Some of the hot combustion gasses are forced down the return tube, and reintroduced into the primary combustion chamber.  This has a supercharging effect, and creates a strong draft in the stack.