EKO 60 and smoke

[Sizzler]

I'm getting a steady stream of grayish smoke out my stack during the first few hours of the burn while the wood is being charcoalized. I've fiddled around with the settings to the point of frustration and cannot seem to correct the problem. I burn full out once each day to charge my tank, and then live off the stored heat until the following day. There is very little if any idle taking place during the burns. On average, it takes about 4-6 hours to bring my tank from 130-180 so I believe the boiler is putting out a decent amount of heat.

My fires during Nov and Dec had taken place after dark so the smoke thing may have went unnoticed. What got my attention was the fact that I started to see some scaleing on the walls of my lower chamber and my chimney cap went from clean to stained. Can also see some creasote staining on the pipe below the cap. My flue temps seem low and tend to hover around 225-250 throughout the burn even though I have a roaring flame in the lower chamber. Also getting some dark colored ash when I clean out the bottom chamber. I clean the bottom chamber after every fire.

Today I backed down my primary's to Cave2k's recomendations and once again I have a nice blueish colored flame and no trouble getting into or maintaining gasification. The first couple hours of the burn I have a steady high pressure stream of grey smoke/steam rapidly exiting the chimney. When things burn down to just coals, the smoke stops.

My wood was cut in May and is solid quality Dead Ironwood and Dead Elm that I scrounged and split down small, (mainly 2-4"splits) and dried in full sun in single rows until October when I then brought it into the garage next to the boiler. The boiler room stays between 65-80 and the wood appears to be nice and dry but I have not put a meter to it.

I just tossed in a load of all dry pallet wood on top of the coal bed and still am seeing the smoke now after 30/45 minutes.

My chimney is 35ft up through the house with a 8" liner. Could I be overdrafting?

What are others seeing as far as smoke out the stack ? All comments welcome.

 

[leaddog]

get rid of the cap. Because off the lower stack temp of these beasts a cap tends to restrict and condence on exiting. Also your wood isn't dry enough and alot of what you are seeing is vapor. Wood that was cut in may will not be ideal but will burn but you will have some smoke and vapor. elm also tends to smoke some for me, don't know why but even though it seems dry I think it tends to hold moisure, sort of like oak. Oak takes two yeard to dry.
The lower flue temps also point to moisture as it tends to cool the fire.
leaddog

 

[Eric Johnson]

In cold weather I usually get steam, which makes sense when you consider that the wood contains at least 15 percent moisture, and it has to go somewhere. I get dirty looking icicles forming on my chimney cap when it's down around zero. Other times, I'll get a little smoke right after loading. Most of that I attribute to: 1.) an insufficient bed of coals; 2.) wood that isn't as dry as I'd like. I'll also get some smoke after a night of idling when I think a thin layer of creosote has formed in the hx/chimney/stovepipe. I think when you really crank up the heat after a long period of idling, you burn off the accumulated creosote and this is going to produce some smoke.

Finally, it takes awhile to learn how to get the desired results from a gasifier (or any other boiler for that matter). So I would suggest that you keep playing with it and make a note of the conditions under which you achieved positive results.

 

[sdrobertson]

Today I backed down my primary's to Cave2k's recomendations and once again I have a nice blueish colored flame and no trouble getting into or maintaining gasification. The first couple hours of the burn I have a steady high pressure stream of grey smoke/steam rapidly exiting the chimney. When things burn down to just coals, the smoke stops.

My chimney is 35ft up through the house with a 8" liner. Could I be overdrafting?

What are others seeing as far as smoke out the stack ? All comments welcome.

I would say that you are over drafting - I don't remember who but someone had their primary at 3 or 4 mm and was still getting smoke (to much fuel) with a long chimney run. The words "steady high pressure and rapidly" tell me that you have a excellent draft and maybe you could go down more on the primary's. Also you could try going to one fan - it seems to help lower the pressure in both chambers which might help slow the fuel going to the nozzles. The only problem you might have is during start up as then you wouldn't have a "hot" draft for the beginning of the fire but if you started the fire with some paper in the top chamber and left the door open to quickly heat the chimney before you closed up everything you should still have excellent draft.

 

[Sizzler]

Leaddog, I was wondering myself about the cap. As fast as the gasses exit the pipe, the cap almost appears to restrict the flow and force it out in a horizontal manner. I had removed it during my summer warm weather burns for DHW and it ended my backfiring issues but I replaced it again when the weather cooled thinking I would then have a better natural draft. Probably was a mistake. Do you just run without one and not worry about moisture down your pipe?

Eric, I am questioning how much of what I see is smoke and how much is steam/condensation. Doesn't really seem to make much differnce on the outside temps though. I have been logging each of my burns and getting close to a really good flame but the smoke thing is driving my crazy.

sdrobertson, I am down to running one fan and one nozzle at the momement. I was able to dial in my flame and maintain a more consistant burn with this setup. Have not experimented long enough to say for sure but it looks as though it may be more efficient than the two nozzle approach???. I am very close to running with my primary's closed up tight at the momement but i'll try to shut them down a bit more during tomorrows burn. Can't get them closed completely due to some weld beads in that area. I may have to grind out the corners of the slider plates to shut them down below 6mm. I'm also considering a draft damper to reduce some of the flow. Any thoughts?

Thanks guys

 

[leaddog]

I don't use a cap but I burn year round. Any moisture I would get in a hard rain would run into the bottem of my cleanout tee and leak out and as soon as I had a fire going it would be gone. I don't have to worry about birds but if one did I could use Deans method of roasting. Shannon had one on his also and when we removed it he got a better draft. I just don't see a need for it. Maybe I'm missing something and if I am I hope someone will jump in here. I'm also not worried about sparks flying out as I don't have any and don't see where I'll ever have a stack fire again. I blew up a stone chimmey once with one and thats why I'll never have one in a house.
leaddog

 

[Sizzler]

I'm thinking mabe I have potential for a good draft but the cap is there backing everything up. It's an el cheapo galvanized cap. There is no spark arrestor but the thing seems to be restrictive with a low set hood. I might look for something of better quality. Getting up on the roof with all the ice and snow could pose a challenge at this point.

I forgot to mention that I went to the barn to a stash of 3 year old Maple splits that I had saved specifically for burning in my insert since this was all cut short to 18". I loaded the EKo with it and still got as much smoke. Is it possilble that the wood if fine but it is just an issue with my settings or a to high or low draft??

Anyone else getting heavy smoke prior to establishing a good bed of coals? I'm wondering if it might have something to do with the way I start my burns from a cold start where as others who burn continuously tend to have a good coal bed to work with throughout most of the burn?? Just thinking out loud here.

 

[Duetech]

Hi Sizzler,
If what you are seeing is steam (as has been stated above) and not smoke that's okay. Steam will totally dissipate the smoke will not. Part of what burns in wood is hydrogen gas. When hydrogen burns it actually oxygenates. Roughly grabs a couple oxygen molecules and becomes water vapor. As well, as mentioned above, there is moisture resident in the wood. I have also split dead elm and had it over a year uncovered and burned it in a wood stove and had moisture come out of the end of it. I liked elm but it was a wood that always seemed to force me into more frequent chimney cleaning and was a bear to split.
I am curious for the blocking off of the back nozzle rather than the front nozzle but I only have one nozzle so I don't block any. Just theorizing here but with the U blocks pushed to the back of the unit, forcing the gasses forward, with an open rear nozzle you would get more exposure time for the gasses to ignite (If you are not seeing smoke it's a non-plus issue as you are getting "the burn"). How are your U blocks situated with the back nozzle blocked?

Over drafting is possible but if all things are equal you should not be getting smoke as that initially is a sign of too much fuel or secondary air combustion "blow-by." How high/wide is your blower setting? (to echo sdrobertson in this thread) Even though you have taken your primaries down and you are getting a blue flame it is possible they are not down far enough if your blower is too strong. (I had the problem with the weld bead getting in the way of my primary slider plates and trimmed them down. The bead on one side was larger than the other and prevented equilibrium with the external primary air controller I made. The weld beads prevented me from getting a reasonable mix setting as one was approx. 5mm and the other 8mm)

Another thing is the location of your secondary controls compared to the position of your secondary tubes. Some 60's came with the tubes offset and true adjustment of the secondaries is not really achievable because you cannot close them. Do yours line up and seal if you shut them down? Also some 60 and 80's owners have found that their secondary tubes have broken free from their tack weld and shifted. Realignment/insertion would be needed. They have done theirs with good results. Some have stated their unit seemed to run okay but never adjusted well before the fix. That tells me that there is blow-by around the tubes that may be skewing the mix ratio. Try putting some refractory glue or high temp silicone around the secondary tubes where they come in contact with the boiler body. (I haven't done this yet but am anxious to give mine a good look over and see if I can tweak a little more). There is another trick with the U blocks you can try but I will wait to suggest that and let you try one thing at a time. Best to you...

 

[leaddog]

Anyone else getting heavy smoke prior to establishing a good bed of coals? I'm wondering if it might have something to do with the way I start my burns from a cold start where as others who burn continuously tend to have a good coal bed to work with throughout most of the burn?? Just thinking out loud here.

That might be part of the problem. If I try and get in a hurry and fill it up before I get coals I will smoke and done't get gasification to last and I have to stir things up and sometimes I just shut it off for a few minutes and then stir it up and it will start gasifing. But if you are gasifing then I don't think that is the problem.
leaddog

 

[taxidermist]

I get the same smoke/steam I also have minor scale build up inside the boiler and staining on the cap and chminey. I ran the boiler hot last night when I started the fire with dry wood and it turned the cap a little on the red side and I had a few sparks flying but I know the chminey is clean now. I removed my cap a few weeks back and really did not notice a difference. That was many changes ago so I might try it in the am if we dont get freezing rain.

 

[bird hunter]

Just a thought but it sounds like your damper door may not be closing all the way, a small buidup of creosote can cause a small gap in the damper and let smoke out. I clean mine with a dremel, a little messey but effective.

 

[dzook]

I use a chimney cap with good results. My chimey is close to 30 ft straight up. I had to remove the mesh in the cap as it built up with soot.
I had trouble getting consistant results with fan primary and secondary settings until I installed a barometric damper. I installed the damper after I installed the draft indicator and saw the extreme differances I had with draft. Now the draft is in line with what the eko manual says.

I have dura vent brand insulated 8 in pipe the whole way with a dura vent cap

I got "juice" out the bottom in rains without the cap

 

[Sizzler]

I was looking into the lower chamber during gasification and it appears to be fairly smoke free as I watch the flue gas exit up the rear of the boiler so perhaps this indicates that most of what I am seeing is steam or condensation exiting the chimney. I checked my bypass damper to see if there was any obstruction to it and everything looks to be sealed when closed but I will take a closer look in the morning when everything has cooled down.

As for the positioning of my blocks they are pushed all the way to the rear and tight together. I am open to suggestions as to a better placement for those.

I will try the high temp silicone around the secondary tubes as well. Both my secondary tubes had slowly worked there way out of the refractory and I needed to tap them back in place and line up the holes. For some reason my left tube sticks out about 1" farther than the right. I double checked all eight holes with a piece of wire and a flashlight and they are definately in line now. Had to turn one side with a pipewrench just a little to get them lined up right.

 

[sdrobertson]

I will try the high temp silicone around the secondary tubes as well. Both my secondary tubes had slowly worked there way out of the refractory and I needed to tap them back in place and line up the holes. For some reason my left tube sticks out about 1" farther than the right. I double checked all eight holes with a piece of wire and a flashlight and they are definately in line now. Had to turn one side with a pipewrench just a little to get them lined up right.

This is where to start first before you change anything else. The tubes need to be lined up properly to get the air to the nozzles properly to get good secondary burns. Several boilers have had this problem.

 

[Duetech]

Sound's like you're busy Sizzler.
As far as the bypass damper being obstructed, it is a possibility but check the secondary chamber for a dark carbon discoloration, instead of white ash, on the door and in the chamber. Carbon discoloration indicates that at least part of the smoke is passing through the secondary chamber and that has nothing to do with the bypass damper. If you are getting a lot of carbon/creosote and the damper is sticking or just carbon coated then there is a likely problem there. If the damper sticks mildly and there is only small amounts of carbon with the general creosote coating common to the primary chamber then there is likely no problem with the damper seal. The best clue for mix problems is carbon discoloration in the secondary chamber.

With your back nozzle blocked off I would suggest standing a standard firebrick upright (if it is tall enough) between the two U blocks, if you only have two blocks, in your secondary chamber to create a forced forward flow through the channel. (I don't know if you have three U blocks or if there is room for the fire brick if you have three) My recommendation is to open the back nozzle and close the front nozzle and keep your U block's pushed to the rear and force the fire forward to get time for a more complete burn BUT I am not familiar with your units specific burn characteristics. Either configuration should work.

Now that you have your secondaries in place I would try to tack weld them before you apply the silicone though they may hold with out the weld. I think "thermal stretching" may have caused them to move and if that is true then the silicone will not hold. (if the amount of movement was severe it might be wise to check the secondary adjusters for damage as anything that can break a weld can likely "torque" a control) That said, the fact that the tubes moved and were out of alignment and you were still getting half way reasonable burn times and settings indicates that the silicone would still be a good choice and will likely yield a better tune adjustment.

 

[Eric Johnson]

Those of you who are experimenting with using only one blower should consider putting a switch on one or both of them so that you have the option of easily using one or both as conditions dictate. If you haven't done that already.

As someone (Cave, I think) stated, steam will dissipate within 10 or 20 feet of the chimney. Smoke will tend to hang around longer. For whatever reason, I always get the "cleanest" burns when the temps are above 20.

 

[leaddog]

I will try the high temp silicone around the secondary tubes as well. Both my secondary tubes had slowly worked there way out of the refractory and I needed to tap them back in place and line up the holes. For some reason my left tube sticks out about 1" farther than the right. I double checked all eight holes with a piece of wire and a flashlight and they are definately in line now. Had to turn one side with a pipewrench just a little to get them lined up right.

One tube sticking out 1in futher is not right. If you look at the tubes you should be able to see where the tack weld broke and then line it up back there. Mine moved out and bent the adj. but I just tapped it back to the weld and retacked it. If you havent tacked them in place they will move because of thermal expansion and contraction and then your secondary air will not work. I would think rewelding should be covered under warranty but in my case I had the welder so no problem.
leaddog

 

[Sizzler]

I will give the firebrick and rear nozzle a try and see how that works. I'll need to pick up a brick for the trial.

I closed down my primary air to 5mm today (as low as it can go with grinding) Had a really difficult time getting into gasification this way. I opened the lower door for inspection and had a mini explosion.... Got a face full of ash and smoke. I've decided I need to set up my boiler for on the fly adjustment, so i'll probably work on that today after this small fire burns out. Full air for startup and then throttle it down some when everything gets going good seems like the way to go. I can usually get into gasification in less than 6 minutes when the primarys are opened up far enough.

I have wired in a switch to kill power to both fans and that has come in handy but not a bad idea to switch both of them individually.

 

[Sizzler]

I will try the high temp silicone around the secondary tubes as well. Both my secondary tubes had slowly worked there way out of the refractory and I needed to tap them back in place and line up the holes. For some reason my left tube sticks out about 1" farther than the right. I double checked all eight holes with a piece of wire and a flashlight and they are definately in line now. Had to turn one side with a pipewrench just a little to get them lined up right.

One tube sticking out 1in futher is not right. If you look at the tubes you should be able to see where the tack weld broke and then line it up back there. Mine moved out and bent the adj. but I just tapped it back to the weld and retacked it. If you havent tacked them in place they will move because of thermal expansion and contraction and then your secondary air will not work. I would think rewelding should be covered under warranty but in my case I had the welder so no problem.
leaddog

DOn't think I could have tapped the left tube in any farther. I used a piece of wire with a short 90 on it and they both appeared to be bottomed against the back wall of the boiler because I could not feel any gap with the wire and the holes also appeared to be well in line when I checked them using the wire and a flashlight. I was very careful to get them set into place properly so I'm thinking one of the tubes is just a bit longer than the other.. I was under the assumption that the tubes are open in the back and not welded shut but I may be wrong about that.

Does anyone else have one tube sticking out. I thought one of the pics that Eric posted here showed one of his tubes sticking out a bit more also.

 

[Sizzler]

One tube sticking out 1in futher is not right. If you look at the tubes you should be able to see where the tack weld broke and then line it up back there. Mine moved out and bent the adj. but I just tapped it back to the weld and retacked it. If you havent tacked them in place they will move because of thermal expansion and contraction and then your secondary air will not work. I would think rewelding should be covered under warranty but in my case I had the welder so no problem.
leaddog[/quote]


I checked and there is no evidence whatsoever of the secondary tubes ever being tacked into place from the factory. They must have missed it. I measured and notched them for reference and they are already starting to vibrate out again (less than 1/16" so far) so I'll make sure and tack them in place before I finish.

 

[Kemer]

My eko 60 has one tube out further than the other by about 3/8".I put a flexable flashlight down the nozzels and could see light but I still have doubts .As soon as I get a chance I'd like to pull the tubes and clean up the burs and reinstall. I did'nt really see any tac welds.I have a welder so no big deal to re tac

 

[Eric Johnson]

My left tube broke free and walked out. It's impossible to set your secondary air supply if the tubes don't stay put. I had mine tack welded back ($40) and got a refund from the dealer for it. I'd say that if one or both of your tubes are loose, you're not going to have much luck getting a consistent, clean burn.

 

[Wade]

My homemade furnace burns hot and fast and puts the heat into the storage. Right now the temps outside are around -36 Celsius. My chimney has a solid white plume coming from it constantly. For a little experiment I attached a 4" hose to the chimney and ran it into a steel drum. Every hour I emptied a gallon of water from the drum, that is how much a gasifier running at full will produce. The water was fairly clean, would not drink it by any means. By the way, I burn wood from our cabinet shop and it runs between 8-12% moisture, so wet unseasoned wood is not the problem.