Hamish spot-welding the chamber to the drum
After trying several prototype institutional-sized stoves using homemade clay bricks and common construction bricks, I decided to build one using stainless steel sheeting as the primary material for the combustion chamber. I was lucky as, at the time, I had the services of a well-qualified and skilled mechanical engineer called Hamish Lee from New Zealand. Also, I had previously brought a spot welder from the States, so we were well tooled-up for the job.
Hamish laid out the sheets to be cut and bent in a very precise manner and this resulted in a finished product that fit together very well. It took us about two days to make the 8" square combustion chamber and chimney section. The combustion chamber was then spot-welded into an old 55-gallon drum and the chimney adapter rivetted on afterwards. With 10ft of chimney, the draft of air through the stove is prodigious! We fired it up just before Hamish left and we were well satisfied with its performance.
Imagine my surprise when I heard that a luminary of the Rocket Mass Heater world was visiting Pyin Oo Lwin and wanted to come over to meet me. I was delighted to welcome Leslie Jackson, who co-authored the seminal book on the subject, "Rocket Mass Heaters", with Ianto Evans, to our humle workshop. I lost no time in roping Leslie in to giving an impromptu indtroduction on Rocket Stoves to our two most recent volunteers from UC Berkeley, Mike and Lisa. Later, we filled the drum with wood ash, (collected from two local monasteries), and this provided good insulation around the combustion chamber. Then it only remainded to install the chimney through the roof of the kitchen in St Mathews Orphanage and the work was complete.
I hope that the stainless steel material will have a useful life of 2 or 3 years. It's not the ideal material, as it quite expensive compared to the financial resouces of the benefitting institutions and it has to be imported from China. However, it is one more step in the experiment that is "Improved Cook Stoves for Burma" and it will give us useful feedback.
Note the Downfeed/Ash drawer on the left
Hamish gets some help preparing the grate
Leslie explains the principles of the Rocket Stove
The Stove team pose for a shot!