Satamax Antone wrote:Well, no wonders.
Bricks stacked, barrel gap of 2 inches. No insulation i bet? Nor a vertical chimney?
Horizontal exhaust without a vertical chimney doesn't work. Except in very rare occasions.
Try first without a barrel. Seal the bricks with mud. Insulate your core. Then, when the barrel goes on, the vertical chimney goes up at the same time. Even if you have your bench in the middle. Otherwise, it will never work.
Glenn Herbert wrote:On top of the points Max made, you describe a 4 1/2" square burn tunnel. That is a very small system relatively speaking; the usual sizes are 6" or 8". Smaller systems are inherently harder to get right, and put out much less heat too, even when they are running right. So rearrange your bricks to make at least a 6" x 6" core, feed tube, burn tunnel, and heat riser, all the same size as far as possible. What kind and size of bricks do you have?
Satamax Antone wrote:Brian, yes a chimney, not the heat riser inside the barrel.
Well, the gap can be all right at 2", 1.5 i would never advise. Basically, what happens, you have very hot gases, hitting at speed a metal plate, being forced to turn a sharp 90°, then back down against their tendency to rise. Plus, going through a 90° bend creates turbulences, which are no good for the flow.
With a 4.5"² You have 15.9"² You have with that 4.5 riser, about 18 inches of perimeter. X 1.5 for the gap for example so that's 27"², at 2 inches, you have 36"² 32 should be enough. But those 36 are better. The more you increase your barrel gap, the less friction you have, at the detriment of cooking abilities.
But, even with lukewarm gases, they rise. It's nearly impossible to make a RMH work with an horizontal flue. This, with dry stacked bricks. A tight barrel gap. Plus, i bet your transition area between barrel and flue is not that good either. To reassure you. We've all done mistakes. I started with metal rockets. You can't get it right the first time. Except if you follow a plan tightly.
John McDoodle wrote:some firebrick is insulative, some is dense. the light weight ones are more insulative. most people here will tell you that using steel is bad. my small systems use 2-3" gaps and the cook tops range from 400-800F typically. cook top temp depends on many things , burn chamber lenght, riser height, system CSA, etc.
Brian Lanning wrote:
How do you control the temperature for cooking? I was thinking I could cut up some porcelain tiles I have lying around and use them as spacers to get the pots and pans up off the cook top. Mabye a metal rack with some kind of height adjustment would be better though.
Satamax Antone wrote:Brian, the top of the barrel can reach a good 220C° with a 6 incher. Even higher temps have been recorded.
Bricks need to be insulated imho. First of all, stack these on edge, not flat. You will have less mass in the heat riser, which means clean burning will happen quicker. And yes, you need a vertical chimney. You need a fair gap, like 4 or 5 inches between heat riser's outer surface, and the flue exit, if cut in the side of the barrel. And the flue transition there, should be at least 150% of the CSA of the riser, so 6 inch diameter for a 4" riser.
thomas rubino wrote:Brian; My barrel top can reach 1100 F, it has an 8" glowing orange circle over the riser at this temp , normal running temps are 600-800 F , 8" system , all temps taken with a digital temp gun.