Sputty Posted April 13, 2017 Report Share Posted April 13, 2017 . Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted April 13, 2017 Report Share Posted April 13, 2017 General guess is 10,000btu/cf so 200,000 seems good. Chimney sounds a good size too. That's worked out as 3x downward pull + 1/3 horizontal pull. You can make a good quality forced air burner for half the price of a 'new' venturi burner Link to comment Share on other sites More sharing options...
neilestrick Posted April 13, 2017 Report Share Posted April 13, 2017 Call Ward Burner. Don't skimp on safety systems. Link to comment Share on other sites More sharing options...
Mark C. Posted April 13, 2017 Report Share Posted April 13, 2017 I think he is in UK as far as Ward Burners There must be a few places like that non UK as we'll. Link to comment Share on other sites More sharing options...
Sputty Posted April 14, 2017 Author Report Share Posted April 14, 2017 . Link to comment Share on other sites More sharing options...
Marcia Selsor Posted April 14, 2017 Report Share Posted April 14, 2017 Here is how to estimate what you need in Btus straight from the mouth of Mark Ward http://www.claytimes.com/articles/kilnvolm.html Link to comment Share on other sites More sharing options...
Sputty Posted April 14, 2017 Author Report Share Posted April 14, 2017 . Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted April 24, 2017 Report Share Posted April 24, 2017 So, I was firing the gas kiln last night to cone10 and didn't even reach 1psi on my regulator. Thought I could share my figures. The orifice I am 99% sure was 1.5mm or about 1/16th which olsen tells me has a fuction 10,492.70 and 1psi has the function 4.2661. If you multiply them both together you get the BTU which gives me 44-45k BTU max for a size of slightly over 6 cubic foot. I think I am looking at 6-8k btu/cf for my gas kiln conversion even with thin electric kiln walls. Link to comment Share on other sites More sharing options...
Sputty Posted April 25, 2017 Author Report Share Posted April 25, 2017 . Link to comment Share on other sites More sharing options...
Rex Johnson Posted May 2, 2017 Report Share Posted May 2, 2017 I'm terrible at this math stuff...according to the Ward link my 2' x 3' x 4' downdraft requires...?...I'm never sure. That said, my kiln is only 4 1/2" softbrick thick with a 1/2" outer layer of fiber blanket sandwiched within sheet steel and a 7" softbrick flat roof and about a 12' chimney. I have two squirrel cage blowers on with 2" Sticktite burner tips on about 12" length pipes with the appropriate propane sized orifices. My propane tank is a 250 gallon that has 1" gas pipe running about 22' away from the valves. It takes a lot of adjusting and monitoring to get this puppy to cone 10 which is why I decided to go with cone 6-7 clay and glazes last year. Per Ward's formula 2' x 3' x 4' x 30,000 BTUs/cu. ft. = 720,000? At any rate, I can do a strong cone 7 firing, fairly even in 8-10 hours. Link to comment Share on other sites More sharing options...
Rex Johnson Posted January 8, 2018 Report Share Posted January 8, 2018 Interested in new forced air burners for my box so I'm reviving this thread. As mentioned, not sure how the math works. there is Ward but I found these folks and hope to get some answers from them. They have a burner and safety set-up I think I could live with. http://www.cooperworkskilns.com/burners.html Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted January 8, 2018 Report Share Posted January 8, 2018 10,000 btu/ft3 seems a good estimate so 240,000 btu/h for your kiln. Smallest burner on the website seems good for that. I have found with my kiln it seems to use even less that that. Never actually measured it though. In the ward article raku burners are made powerful to quickly fire the pot so I think the 30,000 is way off. The 16,000 9" hard brick might give a better representation to what you have but even then probably worse that 4.5 insulating brick. Link to comment Share on other sites More sharing options...
Rex Johnson Posted January 8, 2018 Report Share Posted January 8, 2018 Just for reference... interior dimensions are appx height 35", depth 27", width 31.5" Link to comment Share on other sites More sharing options...
neilestrick Posted January 9, 2018 Report Share Posted January 9, 2018 Yeah, you'll need to figure out the BTU requirements for 4.5" of brick. In addition to being thinner than the typical 9", there are more gaps, unless you've mortared everything tight and the joints haven't split. You can build those burners pretty easily. The things that cost the most are the retention tip at the end of the burner tube, the pilot valve, and the gas solenoid valve. The pilot valve shuts down the gas if the pilot light goes out, because without a pilot the main burner won't re-light if it goes out, and you'll be pumping unburned gas into the kiln. The solenoid valve works via electricity, so it will shut down the gas if the power goes out, because if the blowers shut down then you'll be pumping pure flaming gas into the kiln, and there will be big flames shooting out of every hole. You can probably build those burners for $600-ish. Link to comment Share on other sites More sharing options...
Rex Johnson Posted January 10, 2018 Report Share Posted January 10, 2018 I think I'll stick with my burners as you suggest, and maybe add the little venturi pilot burners from Ward or someone. Then add the solenoid and baso. But I'm pretty lazy til I get my ADD on... Link to comment Share on other sites More sharing options...
neilestrick Posted January 10, 2018 Report Share Posted January 10, 2018 1 hour ago, Rex Johnson said: I think I'll stick with my burners as you suggest, and maybe add the little venturi pilot burners from Ward or someone. Then add the solenoid and baso. But I'm pretty lazy til I get my ADD on... If wind isn't an issue, just get the little Honewell target pilots. They work great, and you can get them really cheap from other sources online, like $25 each. Link to comment Share on other sites More sharing options...
Rex Johnson Posted January 10, 2018 Report Share Posted January 10, 2018 Well, thought about that, but the kiln is outdoors, and a windy desert outdoors, so...it'd be good to have a little more powerful venturi like Ward sells to do candling anyway. I candle with the main burners, fans off, until it gets up to at least 700-800 degrees before I flip on the fans and turn the gas up. Creates a bit of soot and isn't real reliable ass far as the flame retention remaining inside the ports. Link to comment Share on other sites More sharing options...
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