Bridging of gasification nozzles

[mark cline]

I’m going to throw this out there to anyone with a gasification boiler. I have been having a heck of a time keeping my boiler burning clean with no smoke, but usually after a reload I get into a period of white smoke and blue smoke. I’m thinking there are coals that are blocking the nozzle, not allowing gasification. What can be done to get the boiler back to clean burning? Usually I have to let it smoke and it will correct itself. I was thinking about some sort of protection or partial cover over the nozzle so they wouldn’t get blocked. Any manufacturer that has a factory built in protection or some sort of design to prevent bridging ? My Econoburn has no form of protection.

 

[Woodman1]

Not sure if I'm going to be much help here since my experience is the thicker the coal bed the better. I see smoke if there are not coals over the tops of the nozzles.

 

[mark cline]

Interesting, I can’t really say much about the coals , I usually have a problem about 30 min after a reload, So after its reloaded no chance in rearranging any wood. Thick white smoke and eventually blue smoke then burns clean. But 20 min of frustration

 

[E Yoder]

Every model is different but my experience is more coals are better. I try to keep 4" over the nozzle and sometimes I have 10".

 

[airlina]

Mark, if it only lasts 20 mins that is pretty normal on startup, and I wouldn't worry about it . Mine is very similiar on startup and it typically rights itself once the fire gets churning. Like the others have said coals over the nozzle is good, near the end of the burn I rake all of the coals ovet the nozzle to get that last umpphh. Bruce

 

[mark cline]

So , if it smoking, there is not enough heat for secondary combustion? It’s very frustrating to look out and see the smoke, my secondary burn chamber is light tan color so I know it’s burning clean . I guess this is all part of learning how this works .

 

[Woodman1]

Are you confident in the moisture content of the wood you are burning? After you get a coal bed established there really should be no smoke even after reloading. I like the ceramics in the secondary chamber to be bone white. Tan tells me something isn't quite right

 

[mark cline]

My wood has been cut , split and stacked for 2 years in my barn , moisture content is 18%, mixed maple,ash, beech,cherry. Here are some pictures of the secondary burn chamber, can’t see it burning any cleaner.

 

[brenndatomu]

Here are some pictures of the secondary burn chamber, can’t see it burning any cleaner.

That looks pretty dirty to me...

 

[salecker]

Hi Mark
I have the same thing happen in mine from time to time.
And my smoke follows the same pattern.
I used to head to the boiler when i saw the smoke thinking it had bridged.
Looking forward to see what you find.
My system has worked for years,i just don't have the time to watch it and try to figure out whats happening.
I have looked forward to having time to tweak it and make it more efficiant,but like i said it's been working satisfactorily for me at this time of life.

 

[mark cline]

Well , no that I m retired, I’m home and it has consumed a great amount of time . The last 2 days it has performed much better. Why? Because, I have been busy with other projects and have resorted to leaving it alone and allowing it to do its thing . I guess this is the way it runs .

 

[chew72]

A friend of mine has a vigas with the same dual slot burner and the same smoke problem. It was our guess that the two slots throw off your fuel air ratio. If one slot is 80% blocked it will be allowing less hot gas but it will be getting fed the same combustion air as the other vent. Then in theory the boiler corrects but is a little lean on one and ritch on the other.

That's one big reason I went with a froling as it only has the one slot.