Chad Johnson wrote:Has someone tried an adjustable bell (barrel) height to control the amount of rocket?
If you have a bell the exhaust to the chimney is at the bottom. Say that the system is 6x6 inches and exhaust to the chimney is square, too, you can try to make exhaust rectangular say 6in width and 12inch height. The upper 6inch height of exhaust can be closed with guillotine style doors ( so you can choose the exhaust to the chimney will be 6x12 or 6x6 or anything in between. The more it is open, the sooner this bell will "spill" gasses to the flue. How much difference this makes also depends on the bell horizontal surface size... But it should work. Imo this can work as a bypass and as a regulation of speed of glasses. Obviously the lower parts of the bell would receive less heat if the rectangle exhaust would be full open (6*12).
This option is not possible with flue-only systems...
Well, the principle of a rocket burner of any kind. Is not to be able to to regulate the fire. To avoid unburned gases, soot, creosote etc. So adding a regulation of any kind, you get back onto a normal wood stove, which is not as efficient, and more dangerous, because of the creosote and soot, which are prone to chimney fire.
The usual way to deal with the flat out burning. Is to recover the otherwise wasted heat, from the exhaust gases.