Secondary Air Distribution System

 
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warminmn
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Other Heating: Wood and wear a wool shirt

Post by warminmn » Fri. Jan. 02, 2015 3:45 pm

michaelanthony wrote:That's great, congratulations on the new and improved stove. Have you noticed any differences in comfort or coal consumption?
Only got it going last night, but its much more air tight than my efel. Its been running at 310-320 on the side since 11 last night so thats a good sign, using a baro only so far. Just threw 20 more pounds in and will throw at least that much in later. Its going to hold more than I thought, probably over 80 pounds, but Im taking it slow. I doubt it will take less coal than my efel did, but I can burn soft coal and wood too. Its a Riteway clone without a shaker, now a slicer. Supposed to be super cold out next week so will burn up some of my soft next week.


 
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Lightning
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Post by Lightning » Fri. Jan. 02, 2015 3:58 pm

warminmn wrote:I fired the beast up last night and got quite the fire show. It looked like 10 acetylene torches blazing away when the gases hit the 10 holes on each side.
Nice!! Love that!! 8-) The bit coal and wood should really have big impact with that secondary system installed..

 
Indiana dave
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Coal Size/Type: bit coal, egg to foot ball size

Post by Indiana dave » Sun. Jan. 11, 2015 12:47 pm

I worked in a powerhouse for four years that used stoker sized bit coal. We had chain type moving grates and Detroit stokers. With three boilers maxed out during cold winter months, we would burn up to seven semi loads a day. These boilers had over fire air introduced in the form of six two inch pipes attached to a manifold and introduced into the fire box about six feet above the fuel bed. The air was not heated but, created great turbulence at the top of the flames and almost completely eliminated any visible smoke before the gasses were routed through the fly ash precipitators. But,the fire box was about ten feet wide by twenty feet long and thirty feet high. Also had forced draft fans below the grates.

 
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Lightning
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Post by Lightning » Sun. Jan. 11, 2015 3:01 pm

Indiana dave wrote:I worked in a powerhouse for four years that used stoker sized bit coal. We had chain type moving grates and Detroit stokers. With three boilers maxed out during cold winter months, we would burn up to seven semi loads a day. These boilers had over fire air introduced in the form of six two inch pipes attached to a manifold and introduced into the fire box about six feet above the fuel bed. The air was not heated but, created great turbulence at the top of the flames and almost completely eliminated any visible smoke before the gasses were routed through the fly ash precipitators. But,the fire box was about ten feet wide by twenty feet long and thirty feet high. Also had forced draft fans below the grates.
Wow, that's a big furnace. Would be neat to see pictures of something like that! 8-)

 
Indiana dave
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Post by Indiana dave » Sun. Jan. 11, 2015 3:38 pm

Yes it was quite impressive! Although at the time taking pictures , were strictly forbidden with this company. It was a power house for a major company. It burned so bright, you had to wear dark protective goggles and when you needed to open the fire door for any reason, you had to lower the forced draft and increase the induced draft to keep a negative pressure in the furnace. This prevented getting a face full of fire and smoke! It did go positive on me once after adjusting all the blowers and fans and it happened so quickly, all I could do was turn my face away and got my hair singed. As the grates slowly moved forward, the coal would be consumed to ash before falling off the front end closest to the fire door, to the basement ash hopper. We got some bad coal once and when I opened the fire door to check the level of the ashbed, I was greeted with a three foot tall white hot blob of ash all fused together and about to fall into the hopper, I had to dig and hoe at this mess after it went into the hopper for the next three hours as the hoppers were closed at the bottom and allowed to fill up partially, before you pulled the ashes into a six inch vacuum line which sent the ash to a silo. We unloaded a rolloff box full of ash about everyday. Sorry to get off subject, just reminiscing a bit :)

 
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Lightning
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Post by Lightning » Sun. Jan. 11, 2015 3:45 pm

That's ok, that's really neat! :)

 
Indiana dave
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Post by Indiana dave » Sun. Jan. 11, 2015 4:01 pm

Thanks I'm glad you enjoyed it! The worst part was winter time. Coal would be brought by semi, backed to the coaling grate and dumped. The coal would be moved by conveyor, five stories up and into the overhead coal bin which, would hold 700 tons. The coal was washed at the mine and sometimes would be a frozen 30 or 40 ton block by the time it got to us! We had to use a bob cat and sledge hammers to beat it down through the grate....hated that part :(


 
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Post by nortcan » Sun. Jan. 11, 2015 5:18 pm

Hi Lightning, I may have losted some posts :oops: but would like to know the results from your Secondary Air Distribution System expériences.
According to you: is it woth the work and $ to modify a stove to get air over the fire?
Thanks

 
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Lightning
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Post by Lightning » Mon. Jan. 12, 2015 6:00 pm

nortcan wrote:Hi Lightning, I may have losted some posts :oops: but would like to know the results from your Secondary Air Distribution System expériences.
According to you: is it woth the work and $ to modify a stove to get air over the fire?
Thanks
Sorry I didn't reply sooner. I've been thinking about how to answer this.

Is it worth the time and effort? Well, that's a bit subjective. There are some benefits. For one, I'm able to capture the heat from the volatiles more efficiently with the way the secondary air comes in at top of the fuel bed level. With the way it was before, it came in up a lot higher and I feel it wasn't being used the best way it could be. It was also at a shallow angle pointed at the front of the fuel bed and tended to help burn the coal there and not so much towards the back.

My main objective was to improve combustion and produce more heat thru the entire burn cycle. I can't honestly say there is improved performance with a mature fire. I was unable to prove extra heat production later in the burn by adding secondary air. In my mind, enough oxygen gets up thru the coal bed later in the burn after volatiles are burned off, for an efficient fire.

Was it worth it for me? Absolutely. I enjoyed the experiment and learned a great deal about the combustion characteristics of anthracite.. 8-)

 
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Post by Indiana dave » Sun. Jan. 18, 2015 1:32 pm

After reading some of the posts on here, I have a couple of questions. First, I think it would be advantageous to block the secondary air ports on one of the liners to redirect this air for primary combustion but, if this proves not enough by natural draft, could the electric blower that is used for primary and secondary air on my Clayton 1600, be used to maintain the fuel bed temps? I don't want to melt down the furnace obviously but, I'm looking to get more heat after the gassification stage. I have modified the air intake on the blower to go from completely closed to a full two and a half inch diameter, inlet. If the temp was satisfactory, could I endanger myself by actually over presurring the exhaust and cause CO emissions to leak into the living space? I'm just not too thrilled with the heat out put after it all turns to coke. I'm gone for 12 hours a day so, I realize its going to cool down especially when the wind blows but,when the house is 46 degrees and you only have about three hours before bed, not much make up time. Disheartening, you kind of lose the battle a little more every day :(

 
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Lightning
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Post by Lightning » Sun. Jan. 18, 2015 1:40 pm

You would need to run the combustion blower off of a thermostat so you don't over fire it. Also, this could be potentially dangerous if you are using a manual pipe damper. A MPD would restrict outgoing flue gases causing them to back up into the stove and leak into the stove room when the combustion blower operates.

 
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Lightning
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Post by Lightning » Sun. Jan. 18, 2015 1:42 pm

I think a better option would be to use an actuator to open for more combustion air. Member hotblast1357 did such a thing with his stove and has had great success with it.. :)

 
Indiana dave
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Post by Indiana dave » Sun. Jan. 18, 2015 1:57 pm

Thank you both for the input! Yes I do need to connect the blower through the thermostat but, I'd like to investigate the actuator option also.

 
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Lightning
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Post by Lightning » Sun. Jan. 18, 2015 2:03 pm

**Broken Link(s) Removed**

Here is a thread about his actuator. Hopefully he'll chime in and add more info.

 
Indiana dave
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Post by Indiana dave » Sun. Jan. 18, 2015 3:20 pm

After reading about the actuator set up, it seems maybe the thermostat driven blower, would possibly be the better choice for my installation as, mine is in the basement as well. I know my high end limit on cabinet hot air temp is factory set at 200 degrees. At that point, the blower is to shut off until the cabinet cools down. I'm cautiously, curious as to what my flue temp may climb to, in order to achieve the 200 degree cabinet temp?? Sorry to be off subject here :)


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