# New Turbulators



## Nofossil (Feb 8, 2008)

My new turbulators came in. I have 6 HX tubes in my EKO 25, each 21" long. I installed a set of six turbulators before last night's fire. It's too early to make a definitive statement about the effects, but the temperature drop between combustion and flue was the highest I've seen - about 110 degrees higher than the previous week's average.

There are a lot of variables, and I haven't had a chance to do a scientific efficiency analysis yet. Still, looks pretty promising based on the one data point.


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## Sting (Feb 8, 2008)

May I ask what source you used?

on line?

Local?

I like this spiral design better than mine but in the short time I have been lurking I understand a simple length of chain hanging in my vertical fire tubes could accomplish a similar effect!


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## wdc1160 (Feb 8, 2008)

May I ask who you bought these from?


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## Eric Johnson (Feb 8, 2008)

I really like the chain idea, too. Those look good, nofossil. I wonder if you'll have to clean your hx tubes more or less often with these things installed.

Is that mild steel, or something more exotic?

Do you have a good way of pulling them out of the tubes?

(I'm in interrogation mode today, apparently)


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## Nofossil (Feb 8, 2008)

I had a local metal shop make them. They're mild steel. It takes a somewhat special rig to twist them. The shop had done ornamental ironwork and had a twisting rig that they built for that. Cost me $120 for the six of them. Because they're not perfectly straight and they're a very close fit, they take a little pressure to push into the tubes, and they stay in place (so far). I have a very sophisticated removal tool - says 'Vise Grip' on the side of it.

I'm thinking that a bit more twist might be better. 

I don't know what diameter and length other models would need, but the shop is happy to make them if anyone else wants some.

Zenon also thought he might be able to get them, but never responded to my email.


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## webbie (Feb 8, 2008)

The older Tarm turbulators (for the oil gas side and/or the wood side) were basic steel. The temps reached in the water tube area are generally low enough so that a bent piece like this is not affected....the water around the tubes also tends to keep these areas relatively cool.

I never remember replacing even a single turbulator under warranty.


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## Eric Johnson (Feb 8, 2008)

I wouldn't worry about the heat, either. Mine still slide easily up and down in the tubes.


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## barnartist (Feb 8, 2008)

They look nice NoFo. Seems pricy though, but probably not with steel and labor of twist. I paid like $30 for steel and for them to slice it for me. Twisted them myself, and I have 16 of them suckers. Two big table vises and a big adjustable wrench. It was almost fun.
I think more twist would be OK, I dont get much buildup and I dont burn as well as you. I too have to pull them out with Grips.
Im looking forward to your results.


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## sled_mack (Feb 8, 2008)

Do they need to fit that tightly?  Are you trying to get extra heat transfer by having them tight against the side of the hx tubes?  If not, having them slightly loose makes cleaning easier.


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## jebatty (Feb 8, 2008)

NoFo -- looks great, but since you're the data guy, try the chain idea and see what the difference is. I'd be willing to chip in a few $ for some chain. Let us know. BTW, the chain I used in my Tarm was 1/2" barn cleaner chain, which has links a little longer and wider than standard 1/2" chain. My chain still fit cleanly into the hx tubes, no side contact.


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## Nofossil (Feb 9, 2008)

I am trying to get some steel-to-steel contact for additional heat transfer. I might decide to go looser next time.

I'd be happy to try chain, but I don't have any spare chain that's anywhere near the right size. If I come across any I'll try it - it would be easy enough. 

I'd have built my own, but I don't have a shear, and my attempt at getting a clean spiral wasn't pretty.

I know a shop that does a lot of ornamental work - might be cheaper, especially if I don't specify a non-standard width.

I'm really looking forward to doing another burn with calibrated wood. Right now, I'm in a section of the pile that has a lot of variability and a lot of junk.


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## rsnider (Feb 9, 2008)

not to sound stupid but what are turbulators for anyway?
just to slow down the exhaust in the heat exchanger?
I'm not real familiar with this design yet. but interested and now looking hard into the eko and biomax.


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## Eric Johnson (Feb 9, 2008)

On the new EKOs and the BioMax, the turbulators double as hx cleaners. The levers on the side of the boilers move them up and down in the tubes when you yank on the handle. Saves you having to do it by hand.

Barnartist: You have 16 tubes in your 60? I only have 10, last time I checked.


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## jebatty (Feb 9, 2008)

NoFo -- I'm not sure that steel to steel contact should be the goal. The heat transfer area between the edge of the turbulator and the wall of the hx is miniscule. Would it not be better to seek to achieve a distance between these that maximizes flue gas contact with the walls of the hx? Too close and it would impede flue gas contact. Too far and it would allow flue gases to escape by staying internal rather than external to the flow. The purpose of the turbulator is to cause turbulence in the flue stream so that as many molecules of hot flue gas as possible come in contact with the hx walls.


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## drizler (Feb 9, 2008)

wOW I hope they work for you but for gawds sake don't go back there for any more.   You are paying wayyyyy too much for something you can make yourself.     For future reference  don't ever buy steel at a hardware store ect.   Go to the local structural steel fabricator.  Easy to find they are big enough and stand out and usually in an industrial park.     You can buy a stick of 1/8" mild steel for somewhere around 15 bucks and its 20 0r 22 feet long.   These guys could tell you how to do it .  You don't usually find much like that in a scrapyard so better to buy it new unless you really like to dig and have your tetnus shots up to date.

http://www.hobartwelders.com/weldtalk/forumdisplay.php?f=34


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## steam man (Feb 9, 2008)

rsnider said:
			
		

> not to sound stupid but what are turbulators for anyway?
> just to slow down the exhaust in the heat exchanger?
> I'm not real familiar with this design yet. but interested and now looking hard into the eko and biomax.



Since no one has specifically addressed this I'll give it a shot. Digging deep into my industrial boiler background (turbulators are not used there) turbulators are probably meant to reduce or eliminate the "thin gas film" next to the heat exchanger tubes by increasing the flow velocity of the flue gas next to the tubes. This "thin gas film" really reduces thermal heat transfer to the metal and ultimately to the water. The metal to metal contact is probably insignificant. Keeping them slightly loose may be more prudent. Turbulators kind of reminds me of that gas saver thing that you put in the inlet of your air intake on your vehicle to turbulate the intake air for more efficiency. I think mythbusters did a show on that. As for that thing the air is already pretty "turbulent" and it isn't meant for heat exchange like the fire tube turbulators which seems like they can be effective. I am just wondering what the downside of the turbulators are: the possibilty of stack temps too low, draft problems, clogging up, or whatever. I have faith nofossil will figure it out and inform us. Any other theories on the turbulators?

As for making your own-I have used industrial suppliers for small amounts of metal. Be aware that they may charge a handling fee (say $20.00) for any size purchase plus an amount for each cut.  I have been there. Smaller places should be no problem.


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## jebatty (Feb 9, 2008)

steam man said:
			
		

> I am just wondering what the downside of the turbulators are: the possibilty of stack temps too low, draft problems, clogging up, or whatever. I have faith nofossil will figure it out and inform us.



My experience has been stated in other threads. Mine are the 1/2 inch chain, homemade turbulators. My issue was stack temp too high, 600-900 on very dry pine. With draft adj I got this down to below 700 and falling as the load was consumed. With the turbulators, I now am 400-600 during the burn. No clogging, chain does pick up a little dust, but I'm not cleaning the hx tubes any more frequently than before. I clean when temps consistently start rising above 600. With everything very clean, I'm at 525 max.


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## dadams (Feb 9, 2008)

So, from a newbie to this discussion who is an engineer type just starting to explore renewable source heating options:

y'all are correct that the highest resistance to heat transfer is at the gas-side boundary layer, which is in laminar flow with a very low velocity at the wall and thus a low local heat transfer coefficient.  However, the theory re inducing turbulence to minimize the laminar flow boundary sufficiently to improve heat transfer would probably require an added pressure drop in the tube which I believe is pretty much required to induce a substantial amount of turbulence.  I doubt this is happening from this simple spiral mechanism, and even if it were I might think you would you notice such a flow restriction in your boilers?  A prior comment re metal to metal contact area being insufficient to contribute via conduction is also likely correct due to insufficient contact surface area, as backed up by the alternate chain mechanism perhaps also working.  I would postulate if you are seeing a material improvement that the most likely mechanism is radial mixing of the gas in the tube.  At low velocity, gases will tend to be in laminar flow and not well mixed.  So in a short exchange section, the gas at the wall gets cooled off while the gas in the middle of the tube could pass quickly through the heat exhchanger and come out still hot due to not much radial mixing.  In such case, anything that induced a little bit of turbuelence and radial mixing would perhaps raise the gast temperature nearer the wall and improve heat transfer. Industrially, efficient exchangers have a significant gas-side pressure drop, getting the velocities up and helping turbelence and heat transfer coefficients.  If system requrements don't permit such perssure drops normally a very large amount of tube surface area is required to achieve good heat transfer (plate or Plate/fin exchangers for example)  Just my two cents, but I'd bet a weeks pay on it.


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## steam man (Feb 9, 2008)

dadams-I totally agree with you-it just makes me think about all the considerations such as tube size, i.e. heat exhange area, gas flow veloctiy and mixing of hot/cold gases. I looked at an oil fired boiler not too long ago that had turbulators. My thought on the design for the heat exchanger was that due to the design certain tubes may have not been getting good flow while others were excessive. More soot in the low flow tubes. I wondered if turbulators only in the normally high flow tubes would be a better solution. I did a study years ago on heat transfer in different sections of a large boiler and it was interesting. My mind hasn't stopped yet.

Thaks for the reply.


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## Nofossil (Feb 9, 2008)

Welocome to the forum, dadams - nice to have another engineer here.

In this case, we're dealing with an existing configuration that has a number of compromises built in from the start. I'm pretty sure that the spiral 'turbulators' don't induce much actual turbulence - I suspect as you suggest that the underlying mechanism is in fact radial mixing. At the velocities involved, I doubt that there's much of a pressure drop issue. It's a pressurized combustion chamber in any event - if there were an increased pressure drop, it could easily be compensated for by raising the blower pressure.

Folks have had good results using a piece of chain, which I suspect does induce more turbulence as well as increasing the velocity due to the reduced available cross-sectional area. I'm interested in doing a comparative study. I think the spiral should work better, but in the end the data tells the story.


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## dadams (Feb 9, 2008)

Hi, 

I went out to th EKO site and see now this a forced draft system so perhaps already has plenty of velocity and turbulence.  Hard to tell as I don't easily see where the HEX tubes are and how arranged.  My comments were more based on tube HEX systems I have seen in wood stove or wood furnace, which in general seem to be induced draft and therefore low velocity and not capable of managing added pressure drop (particulalry in absence of bypass for startup).  So if these tubes are not large, low velocity design but instead smaller or higher velocity, not sure what the spiral would change.

Our company does some HEX work.  Typically they are about 1000 tons of solid stainless steel.  Not insignficant, but I am not directly involved in the detail so only speaking from general knowledge

BTW Just having moved back from Germany and studied their construction technique, energy efficiency, and solar design techniques, I am in process of planning a new home based on a few basic concepts:  compact footprint, passive and active solar, PV, exceptionally high thermal mass, an insane amount of externally applied insulation, renewable fuel in some variant as a secondary heat source, and probably a ground source heat pump for low duty summer dehumidification and tertiary heat source if I don't feel like lighting a fire.  I've been thinking about it for 3-4 years, it's going to be a fun project.  Looking forward to conversing with y'all.


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## Eric Johnson (Feb 9, 2008)

I have some pics of the top and bottom of the hx tubes in my EKO, dadams, but they're on my other computer. I'll post them when I get the chance. My 60 has ten vertical tubes running from the bottom of the secondary combustion chamber up through the water jacket and into the stack exhaust chamber. I haven't measured them, but they're problably an inch in diameter. Most people who retrofit turbulators into this type of gasifier see their stack temps drop 100 to 200 degrees. But hang in there, and I'm sure nofossil will soon produce some detailed numbers to chew on. I have the stock turbs, but they're basically identical to the ones nofossil had made. In a tarm, they're zig-zagged pieces of strip steel, instead of the twisted design that the EKOs come with.


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## webbie (Feb 9, 2008)

The TARM boilers use large vertical tubes, about 3 inches in diameter - a very different setup than the EKO. Interesting, because TARM certainly does their homework over there (Denmark) in terms of engineering.


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## dadams (Feb 9, 2008)

Well, you can tell pretty much everything you need to know by stack temperature as it is the ultimate measure of efficiency.  If you've burned all the combustibles and subsequently extracted all the heat, you've achieved the end goal no matter how you get there.  There are myriad possible "engineered" solutions to this conceptually simple task, stemming from each design decision having hopefully positive but also some negative impacts that can themselves subsequently be compensated in other ways.  

I can only presume that if some have achieved stack temperature reductions by add-on bits in the boiler HEX tubes, then either the engineering was not so well done in the first place, or the designers chose not to improve their solution for one or more reasons: cost, complexity, maintenance, hazard, or something else.  Not knowing your boilers, any guesses as to why these "improvements" would not have been done at the factory?


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## webbie (Feb 9, 2008)

Given 1" tubes I can guess that the concern may have been flyash and soot - such a small tube does not leave a lot of room for buildup on the sides of it. In the case of TARM, the turbulators were "stock" on the 8 tubes which exchanged the heat from the oil side, and optional (but easily available) on the side that served the wood chamber. 
As you can see by the cutaway enclosed, this is a fairly simple design with the tubes running up through the water jacket in the rear.


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## dadams (Feb 9, 2008)

Yes, I've just been sitting here looking over the Tarm site and info.  Very nice!  I was really not familiar with these gasification boilers, but I am quickly growing fond of the idea the more I read this AM. Not having been online on this topic for long time like some, are folks generally having more success with Tarm, Eko, Greenwood, ?  Meaning mostly availability, price, durability, reliability.  Understanding this is not an endorsment, I am thinking there might not be so much data available with these.


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## Eric Johnson (Feb 9, 2008)

In the case of the EKO, the turbulators are engineered into the original design. On the current models, they can be moved up and down in the hx tubes to keep them clear of soot and ash. You yank on a handle on the side of the boiler when you load it, and a rocker-arm arrangement makes them move. The crud falls back down into the ash pit/secondary combustion chamber. The BioMax does the same thing, as does the Econoburn, I believe. Tarms and older EKOs can be fitted with turbulators, but you need to brush or scrape out the tubes periodically by hand.

The Greenwood is a different animal than the EKO/Tarm/Econoburn style gasification boilers. Instead of having a ceramic nozzle with a secondary combustion chamber below it, the Greenwood (based on the original design by a guy named Fred Seton) has a huge refractory mass surrounding the primary combustion chamber, with the hot gas being drawn down through the coal bed and out the stack. Some brands draft up and some draft down. My understanding of that design is that the refractory allows much higher firebox temps, inducing seconary burn. Instead of being surrounded by water, the firebox refractory assembly has water tubes running through it. Firetube vs. watertube, I guess. The former has blowers, while the latter typically relies upon natural draft.

Those are significant differences in design and function, but they both accomplish the same thing, which is a clean, efficient burn.

Here's a couple of pics showing the top of the EKO hx with the rocker assembly and tops of the turbulators visible. The steel disc is the open bypass damper. Since I have a very tight squeeze in my boiler room, I attached an old snow shovel handle to the stock handle so that I can move the turbs from the front. Good thing, too, because I probably don't have enough room to manually clean the hx tubes, at least not more than once a year.


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## Nofossil (Feb 9, 2008)

Design of a wood gasification boiler has a huge number of compromises. In the case of the EKO 25, they made one mistake in my opinion - they made the boiler shorter than the other models in the EKO line. That means that the upper chamber is smaller and much worse, the HX tubes are shorter. I have six HX tubes with an inside diameter of about 1.845". They are only 21" long, so I expect that anything that can be done to make them more effective is effort well spent.

If they had made the boiler 8" taller. it would still fit in the same space, but it would be more efficient and burn longer between fillings.

My first fire with the turbulators had the highest temperature drop across the HX tubes that I'd seen - about 110 degrees higher than the previous week's average. Last night, the temperature drop was another 160 degrees higher than that. As I mentioned, I'm burning highly variable wood, so I can't easily do a fully calibrated efficiency run just yet. Numbers look good, though.


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## barnartist (Feb 9, 2008)

Eric, you have me doubting myself. Im really sure I have 16. Sled_Mack, this sound right? Eric, your boiler is newer, but ten tubes (-6) would that mean you would have less transfer, or are your tubes just bigger or deeper?
Id like to see chain results compared to spirals too. Even a small amount of improvement would be worth the change. With only 6 tubes it should be easy to try.


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## Eric Johnson (Feb 10, 2008)

I'm pretty sure I counted ten, but I get the impression that the design of the 60 changed somewhat in recent years. I know the refractory brick setup sure did, because you've only got two u-shaped deflector bricks, while I've got 3.


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## leaddog (Feb 10, 2008)

Eric Johnson said:
			
		

> I'm pretty sure I counted ten, but I get the impression that the design of the 60 changed somewhat in recent years. I know the refractory brick setup sure did, because you've only got two u-shaped deflector bricks, while I've got 3.



Very interesting. I bought the eko60 from Barnartist's uncle that they had gotten together 3 years ago and I have found several things different. There is 16 tubes. The fire box is flat and the pipe fittings are flange. The elect. is 220 stepped up from 110 also.
The flat fire box might cause the bridgeing that some were talking about. My son is going to be hooking this one up this spring and we'll see how things work. I don't see where the changes will be much difference. I haven't had my 80 apart to look at the tubes to see if they are bigger but I suspect they are. It would be easier to weld them in plus putting the turbulizer-cleaning parts in would be easier.
leaddog


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## Eric Johnson (Feb 10, 2008)

When you say the firebox is "flat" do you mean that there's no refractory "trough" above the nozzles. The steel in the firebox is vertical, but there's some refractory pieces on the sides that form a sort of u-shaped chamber above the nozzles.

How many firetubes in your 80, leaddog?


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## leaddog (Feb 10, 2008)

Eric Johnson said:
			
		

> When you say the firebox is "flat" do you mean that there's no refractory "trough" above the nozzles. The steel in the firebox is vertical, but there's some refractory pieces on the sides that form a sort of u-shaped chamber above the nozzles.
> 
> How many firetubes in your 80, leaddog?



The older 60 has a flat bottem, no trough. It is refractory but flat. I have fire brick and if it seems to not flow the ashes down to the nozzel I may put some in to help. 
I don't know how many tubes in my 80. I'll have to look when I get time. I was going to see if I could buy the turbulators and rocker arm for the 60 but I'm thinking that the new ones won't fit. Looks like I'll have to get my thinking cap on again and make something that will. The chain idea might work if I can come up with some way to rattle it??????? To many projects and not enough time.
One other change is the damper as it has rope seals. I'm going to make sure I coat it with grafite good before we use it as I can see where the high heat could cause a problem. If it gives trouble I will replace it with a solid one like my 80. 
leaddog


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## mack7 (Feb 10, 2008)

Eric Johnson said:
			
		

> I'm pretty sure I counted ten, but I get the impression that the design of the 60 changed somewhat in recent years. I know the refractory brick setup sure did, because you've only got two u-shaped deflector bricks, while I've got 3.



Eric, I also think there are more than 10 in there, If you look at your picture you have of them there are 4 just in the chimney opening and I know they go all the way to the sides. I am going to have to tear into mine soon just to check things out so when I do I will count them.


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## sled_mack (Feb 10, 2008)

The older 60's do have 16 tubes.  They are just under 2 inch diameter, if I remember correctly.

The bottom of the firebox is flat.  I rely on ash to keep a trough in there.  The new ones are not flat?  If so, what is the shape?  I've thought about trying to get some refractory to make a V shape, but haven't gotten around to that yet.

Can anyone post some pics of the new 60 at the top of the hx tubes?  I'm interested in seeing how tough it would be to retrofit the turbulator shaker to the old ones.  Does it use the same handle that opens the flap, or a different handle?  Seems chain would be really easy to make up for this since alignment wouldn't be much of an issue?


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## Eric Johnson (Feb 10, 2008)

I've decided to pull the pipe off this afternoon after my boiler cools off a bit and check it out. I'll count the tubes, measure their diameter and snap a couple of pics of what it looks like.

I want to inspect my chimney and scrape some creosote off the rim of the bypass damper opening, so this is a good opportunity to get it all done.

Anything else you guys what me to check out or photograph while I'm back there?

BTW, the EKOs that Zennon is importing now are all the Orlan EKO Super model. The Super is the fancy version with the hx cleaner and cooling coil. Plus, it sounds like there have been some interesting changes in the refractory and possibly in the hx tubes between the two versions.


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## leaddog (Feb 10, 2008)

Eric Johnson said:
			
		

> I've decided to pull the pipe off this afternoon after my boiler cools off a bit and check it out. I'll count the tubes, measure their diameter and snap a couple of pics of what it looks like.
> 
> I want to inspect my chimney and scrape some creosote off the rim of the bypass damper opening, so this is a good opportunity to get it all done.
> 
> ...



Take some pic's of the cleaning shaft connections so I can see if it can be retro fitted to the older 60's
I'm thinking that I might have to rig something up and use the damper shaft to move things at the same time as i open and close the damper.
If you can't post all those pic's you can send them to my email.
leaddog


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## sled_mack (Feb 10, 2008)

Eric,

The older models have a rectangular cleanout plate directly above the hx tubes.  It would give you a much larger area to work through to do what you want.

Like Leaddog, any pics of the connections to the turbulators would be really useful.  Putting a new hole through the side of the boiler seems much more difficult than using the flap mechanism.

Leaddog,
What kind of solid gasket is on your flap of your 80?  Mine had the rope seal, the disintegrated pretty quickly.  Nothing else stayed on the flap.  I ended up putting a big rope gasket around the nipple where the flap makes contact instead.  I put a really long hose clamp around it to squeeze it so that it seals up to the flap a bit.  It's not ideal, but the creasote fills in the gaps and keeps it from leaking.


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## leaddog (Feb 10, 2008)

sled_mack said:
			
		

> Eric,
> 
> The older models have a rectangular cleanout plate directly above the hx tubes.  It would give you a much larger area to work through to do what you want.
> 
> ...



My 80 just has metal to metal on the flap of the damper. It seems to seal well. Barnartist told me he changed his to metal to metal but they had to bend the bracket so it would close tight. I think I might go a head and rework this 60 before we put it in service as it will be out where I can work on it.
leaddog


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## sled_mack (Feb 10, 2008)

The bracket does bend easily.  I had a small chunk of wood get up in there early this year.  Sure enough, when I tried to close the flap it bent the bracket.  Fixed it by clearing it, putting a small piece of wood at the bottom of the flap and slamming it closed a few times.  Seals nice now!


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## barnartist (Feb 10, 2008)

Leaddog, I still use the rope on the damper, but my cousin went metal to metal. I found some extreme high heat glue that finally held my original gasket rope in place.
Be carful not to bend the rod arm that the bracket is attached to, I think I stuck a piece of 1/2 inch wood between that rod and the boiler wall, then used a big nail bar to bend it where it needed to go. 
It seems adding a trough to the upper chamber would help some. For me, and this is probably from my buring habits, I get lots of unburned coals in my bottom chamber. Id like a way to add a grid to the nossils to keep these coals up there longer, but not sure if there is a material that would withstand those temps.


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## dadams (Feb 10, 2008)

High Nickel alloys such as HK-40 or HP-mod should do nicely as they are typically used for furnace tubes at temperatures up to about 1800 F


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## Eric Johnson (Feb 10, 2008)

Well, I stand corrected. The 60 has 16 tubes, just like barnartist said. I couldn't get a tape right over one to measure, but it's right around 2 inches. The turbulators are 1.5 inches wide.

I was pleased to see zero creosote anywhere but the firebox. The chimney is clean as a whistle, and I only had some fly ash and soot in the cleanout. Everything else back there has a thin layer of fine, brown soot. I couldn't get a good pic of the mechanism that moves the turbulators, mainly because the pivot mechanism is under the side panel and not visible from the rear. I can't get my side panel off, but I did before putting it in there, so I know what it looks like. Nothing goes through the water jacket, by the way. There's a shaft running over the top of the turbulators that drives the thing. I'm sure you engineers have special terms for that stuff.

Here's a couple of pics. The one in the lower right shows the lever that rocks the turbulators. The shaft I mentioned is that brown thing just visible through the flash shadow in the upper right above the lever.


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## Eric Johnson (Feb 10, 2008)

Here's a pic of the refractory trough at the bottom of the firebox mentioned earlier. Please excuse the mess!


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## leaddog (Feb 11, 2008)

Thanks, looks like I can copy mine and make it work in the 60. I see how it works now. It don't look like it would be to hard to copy. But maybe I'll give dave a call and see if reto kits are available.
It looks like there must be about 1/4 in clearance on the sides of the tubes so a close clearance isn't important.
The pic's show alot on how the eko is made for the people who haven't seen one.
leaddog


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## sled_mack (Feb 11, 2008)

Hmmmm.....  I wonder if some home-cast refractory would hold up if used to make a trough like that?  Surely it would work better than just having ashes built up like I have.

I'm still confused on the turbulator mechanism.  If you take the top cover off the boiler, is the rod visible?  When you activate the lever, what motion do the turbulators make - up and down?  Where is the point were the rod enters the boiler that it doesn't come through the water jacket?  That's what I'm really stuck on.

If you have 1/4 inch gap on either side of the turbulator, does it do a decent job of keeping the hx tubes clean?  I use a brush made for pellet stove tubes to clean mine.  It's a tight fit, but cleans very well.

A retrofit kit would be interesting.  Maybe some drawings of it would make things clearer for me.


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## leaddog (Feb 11, 2008)

It looks like the rod is up high and has a lever coming out each side of it that is connected to the flat bar that the turbulators are connected to. I'm sure that there is corresponding levers on the oposite end to make the flat bar level.  By moving the outside handle it would rotate the rod and move the levers up and down which would in turn raise and lower the flat bar and in turn the turbulators. I know clear as mud. I'd draw a drawing but I don't know how to post it.
leaddog


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## Eric Johnson (Feb 11, 2008)

I've never taken that plate off of mine, sled, but I do have one. The rod runs right underneath that plate--probably between the two sets of tubes so that you can get a brush or scraper into the tubes. Thinking about it, I'm not sure now whether the mechanism goes through the water jacket or not. Leaddog might be able to answer that question. The turbulators move up and down, I'd estimate about 4 or 5 inches total. There's some resistance when you pull the handle, so metal is hitting metal inside the tubes. But it's not hard to move at all. As to how clean it keeps the tubes, I can't say. Clean enough for the turbulators to move up and down.

As to home casting refractory bricks, I'd like to try that, too. I think you mentioned that you talked to Zennon and he had a better design than the u-shaped bricks that come with the stove. I'm sure it would be pretty easy to build a mold and cast your own. I just don't know if you'd have to get them kiln fired or not. I bet you could get a bag of that refractory that Fred Seton sells and make something out of that.


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## leaddog (Feb 11, 2008)

sled_mack said:
			
		

> Hmmmm.....  I wonder if some home-cast refractory would hold up if used to make a trough like that?  Surely it would work better than just having ashes built up like I have.
> 
> .



I think you could take some fire brick an lay them in some refractory cement an make a trough. I have some 2x4x8 bricks that I think I will cut on an angle. You can buy refractory mix here on ebay. http://stores.ebay.com/FIRE-and-ICE-Supplies
leaddog


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## sled_mack (Feb 11, 2008)

Seems like the refractory there would not take as much abuse as the lower chamber as far as temperature is concerned.  Plus, they will be somewhat protected with ash after the first few fires.  Zenon originally said just putting the refractory in an oven at 400 deg for 5 or 6 hours would be enough to drive out the moisture that causes cracks.  That might be enough for these trough pieces for the upper chamber?

That being said, it seems like it would be a huge advantage to have refractory up the sides of the chamber as well.  The more heat kept in the fire area should greatly help with gassification, no?  The problem I see is any refractory up the sides getting destroyed when loading the fire.


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## jebatty (Feb 11, 2008)

If I'm following correctly, putting refractory up the sides of the firebox may not be helpful. My firebox does accumulate some creosote, which burns off enough so that so far, at least no cleaning needed. The bottom of the firebox is refractory, and stays clean due to the heat below in the refractory tunnel. Manual for the Tarm states that if (unusual situation) creosote accumulates on the refractory on the bottom of the firebox, it needs to be cleaned off.

The firebox obviously is much cooler than the gasification tunnel. Its purpose is to maintain combustion to drive gases into the gasification tunnel. I supose a hotter firebox wouldn't hurt, but I'm not sure it helps.


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## Eric Johnson (Feb 11, 2008)

Thanks for that link to the refractory mix, leaddog. Doesn't sound too hard.

I think that to the extent that the firebox generates heat, it's good to have as much metal exposed as possible for heat transfer. Most of that is done in the hx tubes, but every little bit helps. That said, I think you could cast little ramps on either side to help direct the fuel towards the nozzle. I'm thinking about making some forms for the flame-deflector bricks in the secondary burn chamber so that I have something to replace the stock bricks when they start to deteriorate in a couple of years.


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## jebatty (Feb 11, 2008)

The refractory bottom in the Tarm is sloped on the sides to spill the wood load toward the nozzle. I think there is a compromise in that as the amount of slope increases, the size of the firebox decreases. There likely is an ideal size of round wood that works best, and split wood, with flat and round sides, as well as the size of the splits, may contribute to bridging.


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## ebbci05 (Feb 12, 2008)

I just bought an EBW-100 at the end of Dec. 2007.  Its only been a little over a month and my turbulator agitator has broken.  I was wondering if this is a common problem that I will have to deal with all the time.  I haven't had much luck so far with my boiler and was wondering if anybody else was having problems with theirs.


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## Eric Johnson (Feb 12, 2008)

Welcome to the Boiler Room, gopherwood. I'm not familiar with that boiler, or at least if I am, I'm drawing a blank.

Can you give us a few more details?


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## wdc1160 (Feb 12, 2008)

ebw-100???

ecoburn wood boiler 100??


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## Eric Johnson (Feb 12, 2008)

Right you are, Bill. My bad.

We have a couple of Econoburn dealers here in the forum, so hopefully one or more will check in with some information and help. If not, start a new thread and I'm sure you'll attract some help.


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## Nofossil (Feb 12, 2008)

We _have_ drifted some distance from the original topic....

Turbulators seem fine, and pretty consistently lowering the flue temps by better than 100 degrees. I'll start a new thread when I get hard efficiency numbers.


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## jebatty (Feb 12, 2008)

NoFo - clean hx tubes - When you collect data, it may be impt to clean the hx tubes frequently, as dust/soot on the tubes has a material impact on heat transfer. Accurate data will need a constant state of hx tubes. 

I think most of us are aware of, but may not pay too much attention to, is the importance of clean hx tubes. For example, I have been brushing the hx tubes about 1/mo. When I brushed the tubes today, and immediately fired up the boiler, I saw a 100 degree drop in flue temp. There really didn't seem to be much in the tubes. Sight exam is deceptive. This will be a reminder to me to clean the hx tubes more frequently.


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## Nofossil (Feb 12, 2008)

jebatty said:
			
		

> NoFo - clean hx tubes - When you collect data, it may be impt to clean the hx tubes frequently, as dust/soot on the tubes has a material impact on heat transfer. Accurate data will need a constant state of hx tubes.
> 
> I think most of us are aware of, but may not pay too much attention to, is the importance of clean hx tubes. For example, I have been brushing the hx tubes about 1/mo. When I brushed the tubes today, and immediately fired up the boiler, I saw a 100 degree drop in flue temp. There really didn't seem to be much in the tubes. Sight exam is deceptive. This will be a reminder to me to clean the hx tubes more frequently.



I have to wait a bit to get any kind of buildup. I keep mine pretty clean.

For me, flue temp varies a lot, within a burn and from one burn to another. I'd like to understand better what affects it. I've also been looking at the difference between secondary combustion temperature and flue temperature. That's probably a better indication of both turbulator effectiveness and HX crud buildup.


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## ebbci05 (Feb 13, 2008)

The EBW-100 is an econoburn 100,000 btu gasification boiler.  Right from the get go I have had numerous problems.  First, I had a leak in the bottom of the boiler at one of the studs.  Then, when we had it hooked up the pressure relief valve leaked and would shut off.  Now, just a couple of weeks ago, my turbulator arm broke from the agitators.  I also can't seem to keep the temp up unless it is not windy and 20 degrees or higher.  I bought a 512 gallon water storage that has two coils in it. One to heat the water and one to feed my domestic hot water.  But I haven't been able to utilize this because my boiler won't get it up to temperature and keep the house warm.  Econoburn shipped me a new EBW100 because of the leak, but I am hesitant to install it if I am going to deal with these problems all over again.  The boiler is only a little over a month old    Mine seems to gasify good at start up and then seems to slow down at halfway.  It goes better if I stir the wood around or add some kidling.  Once you get the pile of coals ift does good but it takes so long to get there.  Anyway any advise would be helpful.
Eric


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## jebatty (Feb 13, 2008)

I don't have an Econoburn, so I'll let those people respond as directly as they can. I sense not only your frustration but also disappointment in what you hoped to be a great experience. I trust things will work out, even if a rocky start.

The theory and mechanics are pretty straight forward. A firebox, forced draft, and chimney on the burn side.  If the draft fan is working, and the chimney is producing good draft, the fire side should be OK. On the plumbing side, hot water out, some sort of control on the return to insure that the return is not too cool, and a pump to push everything along. On the electrical side, an aquastat to sense boiler temp and turn the pump on, with a hi-limit and probably a lo-limit control. I know this is simplified, but think through the operation carefully. Something obviously is going wrong, and maybe you can isolate what that is. That will be the clue to get you in operation.


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