# New guy - long post



## sled_mack (Jan 15, 2008)

Hello,
I've been lurking for a few days now, and figured I'd get some comments on my system.

Overview:
I've got an EKO 60 in a boiler shed about 150 ft from the house.  Also in the shed is a storage tank (non-pressurized) with about 2700 gallons of water in it.  Pex underground to the house, where a flat plate heat exchanger is used to heat the existing house oil fired hot water system.

Now for the details:
I've added firebrick to the lower chamber of the boiler to direct as much gas as possible to the front, then along the sides to the rear of the boiler.  My unit is 3 years old, so I had to make my own turbulators.  I used 3/16" round rods with fender washers bent to 90 degrees and welded to the rod so that the gasses in the tubes see the bottom of a V, each V rotated 90 degrees from the last one.  Works really well, suprisingly.

The manifold on the top of the boiler is 1 1/4 in pipe.  I've got two UP26-64 pumps pushing into the storage tank.  Each pump is on 1 in pipe, goes to 2 hx coils in the tank, flow is from top to bottom.  Coils are 3/4 in tubing.  I've got manual divert valves from just after the pump to the returnn manifold for cold starts.  (There are also hand valves to do all sorts of different things, but this is the steady state config.)

One of the pumps is controlled by the EKO controller.  I added an aquastat to control the other.  The probe for the aquastat sits right on top of the boiler steel.

I've also added an off delay relay to control burn time.  I typically fill the boiler with wood, reset the timer, and let it burn for 4 or 5 hours before just shutting down the EKO controller.  The pump with the aquastat protects the boiler from over heating.

I've also got a resistor in parallel with the EKO thermistor to get the controller to burn to hotter temps.  I can get my water exit temps up to 200, where as I was only getting about 170 without the resistor.

The storage tank has 4 coils for extracting heat from the tank.  Coils are 3/4 in tubing.  Flow on these coils is bottom up.  Tank is only 5 ft high, so it's hard to maximize stratification.

There is another UP26-64 pump in the basement pulling water from the coils.  Originally, I had an OWB and was using a "wrap around" config for the hx.  That is still in place, but there is also an hx in the return line to the oil boiler.  The pump for the wrap loop only comes on if I can't meet the required temp using the hx in the return pipe.

These two pumps are controlled from a home grown control system.  I used an Allen-Bradly PLC to do the outdoor reset and control the pumps.  I've also got thermostats with PI control, so I can monitor the % on time for each zone, and bump the reset temp if any zone is running too long.

Heating system within the house is 8 zones plus DHW.  All but 2 zones have radiant floor (those will by next winter, also).  Radian is staple up with thin plates (read - bent flashing).  Most rooms still have the original baseboard - flow is through baseboard then radiant.  One room has 3 large castiron radiators - flow is through radiators then radiant.  In all cases, baseboard was there first, and left in place in an effort to use the lowest water temps and get the benefit of warm floors.

Typical operation:
Normally, I feed the boiler twice a day, once morning and once night.  Using the timer prevents the fire from burning out.  That big storage tank allows the boiler to burn flat out until the fire is gone completely if I'm not there to feed it more wood.  That got old fast, so the timer was added early on.

Once the tank is up to 180, the system is easy to keep going.  If it's warm out, I can get away with only feeding once a day.  Or, twice a day and setting the timer for 2 hours and using less wood each time.

Under normal operation, my stack temp is usually about 200 deg F.  I can't get any lower without losing a good lower chamber flame.

I'm in my thrid season with this, and really have no complaints.  With the current price of oil, I'm sure it will pay itself off this winter.

My post is really looking for comments.  If anyone sees anything I'm doing that is wrong, let me know.  I know the control systems portions, but nothing of the gassification theory.  Anything I know, I learned from the guy who sold me the boiler or from experimenting.  I could be missing something big here, and just not have thought of trying it.

At this point, I realize that my biggest improvement would be digging up the pex to the house and adding more insulation.  (Right now, it's closed cell foam around each pex, wrapped in foil bubble, in a Central Boiler sleeve to keep water out, in an 8 inch corregated pipe for some additional protection.)  But anything I can squeeze out of the system is a help also.  

Questions I do have:  (I'll post separately if this is too long to get responses)

1.  How do I know if the pumps from the boiler to the tank are size properly?  I tried two smaller pumps at the beginning of this year, and found that I got less heat transfer per wood used.  So, the pumps I have are better than smaller ones.  But what if I go bigger?  At what point does the return go away?  Obviously, this is an expensive experiment, so I'd like some input.

2.  I get just a bit of smoke out of my stack.  It mostly goes away once the storate tank reaches 180.  But, the bottom chamber always has light gray fly ash, not dark and sooty.  Is this normal?  Could I be better adjusting my air flow?  Anyone else with this boiler that has an idea what their air adjustment screws and fan dampers are set for?

Thanks for reading and for any comments you have!


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## Bartman (Jan 15, 2008)

sled_mack,
 Welcome to the forum, it's great to have you aboard. It sounds like you've got a great system. Although I don't have a gasification boiler yet, I'm looking into controlling my old NewYorker and oil boiler by PLC myself. We all could use input from you about your system.


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## Bartman (Jan 15, 2008)

Oh yeah, if you have some pics, that would be great.


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## wdc1160 (Jan 15, 2008)

I think you have a sophisticated enought system to warrant a some type of logging.  

Check out Nofo's site.  nofosil.org  
He is a logging and analysis wizard for sure.


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## Eric Johnson (Jan 15, 2008)

Hi sled-mack. Thanks for sharing. Sounds to me like you've got a pretty good handle on your system. I like the timer idea a lot. You're getting about the lowest stack temps I've seen. You definitely don't want to go any lower than 200, or you risk condensation. How do you control the temp?

I found that I had to take my secondary air controls out a full 6 turns to eliminate the smoke on my 60. It was intermittent at the factory setting of 3.5 turns, but backing them out a few extra turns solved the problem. I glued modified (shorteded) wire nuts to the threaded rods that comprise the secondary air adjustment so that I could play around with them more easily. If the problem persists, you might need to open your primary air controls a bit. They're behind the plate that the blowers are mounted on, in the upper corners. I keep the sliders on the blowers at about an inch. The dealer said to open them up as the weather gets colder.

Your ash sounds fine. Fine, gray ash is what I get, too. Even better is powdery white ash, but I've never seen that, perhaps because I've never really run my boiler at capacity.

You can buy a new controller for the EKO that reads out in F. and allows actual settings up to 195 degrees. It may not be worth $250 to you, as you appear to have a pretty good handle on your controls, but it's nice to see the company continuing to make adjustments for the North American market. That tells me they're serious about the future.


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## sled_mack (Jan 15, 2008)

Bartman,
The PLC is a MicroLogix 1200.  Chosen because I could get it cheap off eBay, I had the programming software/cable available from work, and I am familiar with programming it.  Any brand with analog I/O will do the job.

For temp sensing, I am using thermistors.  I had to set up voltage divider circuits to get the changing resistance to read as changing voltage from 0 to 10 VDC.  Took a bit of experimenting to get the scaling right, but it works fairly well.  Also, getting good contact to the pile was a challenge.  I had to use thermal conductive paste between the pipe and the thermistor, wrap it tightly in electrical tape to eliminate drafts, put a hose clamp on to hold it tight, then wrap in pipe insulation and tape some more.

The discrete inputs are 120 VAC, so I used the hot wire from the circulator pumps wired to the inputs for pump running feedback.  I found that one zone is always calling for the most heat, so I only monitor the on time of that zone.  The thermostat is set for a 20 minute cycle time.  I use a linear scale to add 0 to 10 degs to the reset temp once the zone is on between 70 and 100%.  Seems to work well.  Lots of solar gain in this zone and lots of loss out the A-frame ceiling/roof.  During the day, the on time is low, at night it runs about 60 to 80%.  Not bad, considering 50% is ideal in the controls world and 100% would be ideal for heating/comfort as long as it maintained the set temp.

I use a relay to break the signal from the zone control board to the boiler.  When the water from the storage tank is no longer able to heat the house, the pump drawing from the tank is turned off and the boiler is enabled.  Selector switches allow the system to be put in manual and enable the boiler all/none of the time, and the same for the pump.

The water temp is maintained by just using a hysterisis loop around the reset setpoint.  I'll let it get 5 deg above setpoint, then stop the pump from the storage tank, then let it get 5 deg below setpoint before turning the pump back on.  Not real tight control, but it works and doesn't slam the pump on/off as often as a tighter loop would.

I monitor the water temp from the storage tank.  If it's too far below the reset temp setpoint, I'll switch to oil.  I also have an aquastat in the tank that is set for 140.  If the water gets below that, I switch to oil also.  The aquastat was in place before the PLC, and was used because I didn't want to run out of DHW.  I've got to rethink that logic a bit now.  There is still usable heat in the tank for heating the house, just not for DHW.  DHW is a priority zone, so I can switch to oil for that and back to the storage tank for heating the house.  I just need to put some time into thinking more about those transitions.

Anything I missed that you wanted to know more about?


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## sled_mack (Jan 15, 2008)

Eric,
The timer was the idea that saved the boiler.  I was frustrated with it always burning out.  It seems to me that blowing cold air into it when it is out of wood is a bad idea.  And it takes a long time for it to figure out that there is no more wood.  Granted, some of the wood in there smodlers, causing a loss of efficiency, but I don't think it's too bad.  Once the fire has burned down far enough, the coals seem to collapse when the fans stop and sort of seal off the chamber nicely.   To restart, I just rake the coals, put more wood on, start it up and open the dampers on the fans about half way for about 20 minutes.  This gets the fire going and heats up the lower chamber so that I can close the fan dampers to about 1/4 open and it keeps a good fire going.  I've found that getting the fire a little extra hot at the beginning, then shutting it down a bit, makes a big difference in how the fire will burn for the next 4 hours.

I don't have any automated means of controling my stack temp.  I simply adjust the opening of the fan dampers and let it go.

But, it sounds like I may have some adjusting to do there?  I'm only open about 3 turns.  At the same time, my fan damper is only open about 1/4 of the full 90 degrees, so maybe 5/8 of an inch.  I didn't even know there were adjustments for the primary air behind the cover - I've never had the cover off.

It's all a delicate balance.  What ever I do, I want to try to keep the fan dampers from being open too much.  Burning it hotter and faster will just mean more up the stack if I can't move it to the storage tanks fast enough.  Eliminating smoke means a cleaner, more efficient burn.  But if I'm losing more heat up the stack, my overall efficiency of BTUs from wood to storage tank may end up being reduced.  Is that logic right?


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## Eric Johnson (Jan 15, 2008)

Well, here's what it looks like under the hood. You might find the secondary air control to be an interesting design.

As long as you can monitor your stack temps, I think it's safe to experiment with the secondary air controls. Note that it's not a one-per-nozzle situation. The nozzles get air from both the right and left sides. I think every installation is going to require different settings, since the air supply, etc. are all going to vary. In my limited experience, the way to get rid of smoke (assuming you have dry wood) is by increasing the secondary air. Wet or green wood is going to produce a thin stream of blue smoke no matter what you do, especially if you use it to try to get gasification going.

Your theory on the relationship between air supply and efficiency sounds as good as any other I've heard. I don't think anyone has completely figured that out, at least not that I've seen. But we've got guys "working on it"--the Boiler Room Data Geek Squad is on the case.


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## sled_mack (Jan 16, 2008)

Eric,

You've got a 60, so I'm curious what size pump you have circulating through it?  Also, are you pushing or pulling?  In my case I'm pulling.  Considering the options I wanted to have for valving to the house directly, coming back through the tank, simultaneous feed to both, and on, and on, I couldn't find a good way to push through the boiler, so I had to pull.

Head pressure is everything for the flow rates on these pumps.  Each pump is in a 1 inch line.  Pushes through about 15 ft of 1 inch copper to a T which then reduces to 3/4 inch.  Each 3/4 inch leg is a 60 ft coil for the hx.  Then T to 1 in copper for another 15 ft, and T into the 1 1/4 black pipe return.  Pressure should be low, and GPM should be high.  I think.....

Also, if you are considering a timer, be very CAREFUL  You need to have an aquastat to turn on the pump to prevent over heating the boiler.  The smoldering hot coals are enough to boil the water in the jacket above the upper chamber without the pump coming on once in a while.  It really does work great, and I wouldn't be without the timer, but you need the aquastat.


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## sled_mack (Jan 16, 2008)

Another question...

Barnartist and I have been trying to help each other for quite a while now.  (Zenon introduced us.)

He tells me he is considering blocking off one nozzle.  Makes sense if he is idling too much.  But I have some questions about how that works, and if it might help me as well.

If you block off one nozzle from the top, so all primary air is now forced out one nozzle.  But the secondary air is still going out both nozzles.  How do you balance for that?  Open the secondaries more?  Close off the primaries by half?  It seems to me this would be quite an upset to a delicate balance, no?

Furthermore, I've got a decent channel that forces all hot gasses from the rear nozzle past the front nozzle, then around to the sides and to the back.  If I were to block one channel off, it seems it should be the front one.  The fire from the back nozzle would have more combustion time, and would get additional heated air from the front nozzle if it could use it.  Am I on the right track here?

Option 2 would be to force all gas from the front nozzle to the back, then to the left side of the chamber such that it has to come to the front.  The front of the channel would be closed off, so this air stream would pass in front of the channel and along the right side of the boiler to reach the back.  That's quite a rat's maze, and I think it would take some custom refractory, not just my store bought fire bricks.

Finally, would this buy me anything?  It seems as though the temp rise across the boiler is the same regardless of having one or both pumps running, a slight difference at best.  So, if blocking one nozzle doubles my burn time without reducing the water outlet temp by too much, I may be able to extract more BTUs to the storage tank per wood consumed.  Am I on the right track here?  Or am I missing something?  Since I've only burned about 2 cords of wood this year so far, I'm not in a rush to make changes that could make things worse.

Is anyone actually doing this?  It seems that the wood that is away from the nozzle isn't going to burn very well, and may not "fall" into the coals of the fire as the fire burns down.  So it might be a way for me to get more heat per wood consumed, but not neccessarily significantly longer burn times.

Thanks for all the feedback so far!


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## Eric Johnson (Jan 16, 2008)

I have a Grundfos 26-96 on one 1" return line (200' loop) and a Taco 007 on another 3/4-inch return line (100 ft loop to the greenhouse) and another 007 circulating supply water into the return through the cooler parts of the heating cycle.

Current theory dictates putting your pumps on the supply lines and "pumping away" from the boiler, but I'm an old-school "cooler water is better for the pump" kind of guy, so that's how I piped mine. At the moment I'm having a problem with the 3/4-inch line. It's either a bad airlock or a bad pump. I think the 007 might be undersized for the job, so it may well be the latter. I don't think the 1" line has enough capacity to transfer all the heat that boiler is capable of producing, though I doubt I've ever run it at capacity, at least not for any extended period.

I like the timer idea, but have my hands full trying to get my storage and some other loose ends tied up this season. Hopefully next winter I'll have the time and experience with this rig to experiment some more. I assume my 200-degree overheat aquastat would handle any overheat problems encountered, although my main pump is set up to run at any return temp over 160, so it should dissipate the heat regardless of whether the blowers are running or not.

Do you recommend shutting off the circulation along with the blowers when the timer kicks off? That would help the boiler retain heat, but the downside, as we've discussed, is the potential for overheating.


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## sled_mack (Jan 16, 2008)

Hmmm...  my 64 is smaller than your 96, but the second 64 is bigger than your 007s.  Probably, about the same capacity if all pumps are on.  Still wondering if more would be better?

I use the timer to cut power to the controller.  But, I had the aquastat installed before the timer.  If I didn't have the aquastat at the time, I probably would have just put the timer relay contacts in series with the power to the fans.  Same affect, but keeps control of the circulator.

Edit to clarify:  Yes, I do recommend shutting down the circulators when the timer shuts down the boiler.  Keeping the upper chamber hot, results in a much quicker firing at the next load.  All you need is over heat protection.

My original thought was to use only one pump till the boiler got hot, then have the second pump start up at higher temps.  For the most part, that works, but it doesn't warm up that much faster with only 1 pump.  

I'm actually going to rewire the relays that control the pumps so that both pumps run if either the controller OR the aquastat are calling for circulation.  I think it will transfer more heat, and give me some redundancy should one pump fail.


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## sled_mack (Jan 16, 2008)

OK, I opened the secondary air screws 3/4 turn each when I started the fire tonight.  No visible difference in lower chamber flame or stack temp.  Maybe more tomorrow.

But, I have this question - How do you distinguish between smoke and just water vapor/steam coming out the stack?  If the weather conditions are right, I got virtually no smoke.  Tonight, it's very damp outside, and I have a light, whispy smoke.  But when the wind blows it down to the ground, it has no odor, no smokey smell to it.  If I open the lower chamber, there is no smoke apparent and no odor from that either.

So, if my lower chamber and my stack don't have dark colored build up, do I have a smoke issue?  Or is it just water vapor from wood that is not dry enough?

I do have some pine that I am mixing in.  I just started this week.  It is left over from last winter.  Hard to refuse - it was cut to firewood length, delivered and stacked next to my wood pile for free.  It was a bit green last year, drier this year, except it is not covered like my good wood, so it is damp from snow on it.  Leaving it sit in the boiler shed for 24 hours gets most of that surface dampness off.  As long as I mix it in at less than 35% per load, I don't notice any difference.  Mix in too much, and everything falls apart.


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## Eric Johnson (Jan 16, 2008)

I get steam and vapor when it's below zero. Other than that, nothing except when it's getting up to temp. I noticed that unlike tuning a carburetor, you don't see immediate results when you change the secondary air settings. I don't know why. I would suggest opening them up to 5 or 6 full turns and running for a cycle or a day or two. I think you'll notice the absence of smoke. There's an optimum setting for your installation--you just have to find it.

Even when these boilers are smoking, it's nothing like the smoke I used to get with my old smoke dragon. Usually, about all I get for smell is kind of a toasted wood smell.

I think the lighter the ash and deposits on the lower chamber door and reflective bricks, the better. Darker deposits imply incomplete combustion. It's one good way to monitor how things are going.

Getting back to smoke for a minute: Before I adjusted my secondary air, I couldn't tell from looking at the gasification flame that there was smoke coming out of the chimney, because it was just full of yellow, orange and occasionally blue flame. It looked complete, but it wasn't.

On the vapor, I've noticed that in very cold weather, you get the vapor during the first half of the burn cycle. I think that's the water vapor coming off the wood, which you have to remember, has between 20 and 30 percent moisture content (relative to the weight of the wood). When you get a ways into the cycle, however, the vapor disappears. My guess is that most of the water has steamed off, and now your boiler is working with dry fuel. That's another good argument for increasing efficiency by filling the firebox up as much as possible. Otherwise (like me), you're constantly introducing smaller loads and the resulting need to burn off the water. Come to think of it, maybe that's not the case, but it sure sounded good.


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## leaddog (Jan 16, 2008)

sled_mack said:
			
		

> Hello,
> 
> Now for the details:
> I've added firebrick to the lower chamber of the boiler to direct as much gas as possible to the front, then along the sides to the rear of the boiler.  My unit is 3 years old, so I had to make my own turbulators.  I used 3/16" round rods with fender washers bent to 90 degrees and welded to the rod so that the gasses in the tubes see the bottom of a V, each V rotated 90 degrees from the last one.  Works really well, suprisingly.
> ...



It sounds like you changed the refractory brick in the bottem from the factory ones. Just what did you do. Pic's would help. Nofossel did something like that but his would burn out after time. What are you using. I'm sure that any time you can keep the gasses mixing with air and burning it will help. with both nozzels having the gasses directed into the same chamber it might help getting them to fire sooner. thanks
leaddog


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## sled_mack (Jan 16, 2008)

Eric,

I was at 3 turns, and thougth I'd go out slowly till I get to 5 or 6.  I let it go for about 2 hours before going out and looking at it, to give it time to settle in.  I'll go to 4.5 turns tomorrow morning and see what happens.  Since I'm not in a bad situation right now, small steps are better.

Leaddog,
The factory blocks are under the nozzles.  (Oddly enough, I only got 2 with my 60 - some people got 3?)  The curved refractory that came with the boiler is at the very back of the chamber, cupped forward.  The U shapped refractory slides back almost against it.  There is about a 2 inch gap between the rear and front U shape peices.  Along the sides of the U shaped pieces I've got firebricks standing on end, flat side against the U pieces.  The top of the fire brick is almost touching the top of the chamber.  This acts to seal off the "tunnel" in the U shaped pieces so that the fire can not go directly to the back of the chamber or to the sides of the chamber - everything comes to the front.  The fire bricks stop at the end of the front U piece to allow the gasses room to wrap around to the sides.

I couldn't get tall enough fire bricks, so I had to lay some down flat and set the others on top of those.  Looking in from the front, they look like bookends on either side of the U pieces.

However, this winter I've had some chunks fall off of my U shape pieces.  And, I've had a few chunks fall from the ceiling of the lower chamber, around the nozzle opening.  So far, no effect on the operation of the boiler.  But I don't know if there will be if more falls off, or what I could/would do about it?

I'd like to know more about what nofossil has done in the lower chamber.  I saw a pic in a post, but a diagram would be really helpful.  I'm going to have to buy some refractory pieces for next season, or try casting some, if the U pieces keep crumbling.

I expect to be cleaning it out this weekend.  Should be a good time to get some pics.


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## leaddog (Jan 16, 2008)

Thanks, That explains it well. Dave at cozyheat said the u-bricks a avilable and not very expensive but I don't know how much. Also the nozzels can be replaced also. did you find that when you added the fire brick that it was easier to get it into gasification or that you got a better burn? My eko80 has 4 u-bricks, and they don't have the curved bricks any more. I wonder why they changed.
leaddog


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## Eric Johnson (Jan 16, 2008)

Yes, the two blocks and the curved bricks in the back is the old style for the 60. The new ones have three u-shaped blocks stacked end to end and no curved refractory pieces at the back. You can buy new blocks from Zenon at newhorizoncorp.com. He's the importer. On his website is says that nozzles cost $50 each to replace, so I bet the bricks are less than that. Nofossil has an older thread (towards the bottom of the pile) detailing his labyrinth design. Do a search for "labyrinth" and you'll find it. There are some pics that show pretty much how it is (was--that one died) built.

You're probably less than 2 hours down Route 12 from me. It's gonna be cold this weekend.


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## Bartman (Jan 16, 2008)

Wow, I work late one night and miss all the conversation.

Sled_mack, the Micrologix 1200 was what I was originally looking for, but every time I bid, I got outbid. When I missed the bidding, the PLC went cheap. Ended up buying a GE/TI/Siemens PLC (305/Series1), I've had experience with a couple of these 15yrs ago. What I do like about this one, even though it's old, is that I can have different types of inputs and outputs depending on which modules are used. For temp control interface I'm using digital temp controllers with K type thermocouples. On eBay there are some neat ones, I'm trying one that is threaded so I'll drill and tap the boiler water jacket(s), and possibly monitor individual zone supply and return temps.

What are the forecasted temps for you northern guys this weekend?


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## Eric Johnson (Jan 16, 2008)

It's supposed to get up to 10 degrees for a high on Sunday, along with lake effect snow. The guy on the tube tonight said we're in for a pretty long cold stretch--up to 2 weeks, which is probably longer than those guys can actually predict with any accuracy. But I think we're going to be giving the old heating systems a good run here at least over the next week. Up in the Adirondacks it's usually about 10 degrees colder than down here in the valley. But we do get our share.


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## barnartist (Jan 16, 2008)

Cant' help but jump in. Sled Mack, after my first day of blocking off the rear nossil with a big piece of flat scrap metal, the results were really, really good. I am trying not to get too excited early, but I was able to go longer on a load on a colder day than on a warmer one. Now, I have been burning allot of cherry, and Im into my best section of my wood where some oak lives. Mybe this efected it too, but it was still a heavy cherry mix. Today I was able to turn my fan openings almost shut and still have a nice small flame at the bottom-just enough heat to keep everything going at a real steady pace. I fired at 930 this morning and was able maintain heat till 10:30. I went out and had a nice coalbed left for the next load. Nice colored ashes in bottom chamber. All of the upper chambers wood burned, even in the rear where the nossil was blocked. I did not stuff the box full, as the rear of the chamber only half to the top. Tonight I gambled and started the burn with the fan openings in that same position. I wasnt sure how this would take off-but as I sit here and type, I am watching my water temp with a wireless setup, and it bounced down about 10 degrees, and slowly starting to climb. Nice and slow. I think it will probably idle still early in the morning, whitch might mean I need to let the sto tank get colder- but without a timer setup, I really want some good coals for that next load of wood. I hope this is the berry's- I think you mentioned about the nossil cover to me Eric. 

Funny thing about that, there is something to be said about the heated air-I had some flame early in my burn coming from that rear nossil still. But none now. Maybe some ash sealed off extra air. I am thinking though I may need a better way to use 1 or 2 nossils on demand besides covering up the whole. Also was able to maintain 300-325 stack. Im not sure I could have shut the covers any more and have it still function. I still think it would be nice to gear it down a speed at a certain part of the burn cycle.


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## barnartist (Jan 16, 2008)

Steve, is it at all possible that setting up the bottom chamber like that caused the re-factory to fail from more heat consentration? Also, does adding insulation to the bottom of the eko help? Our cat loves that spot. I don't know how his hairs aren't singed- its really hot there. I had some fiberglass under there last season, I am thinking about sealing off all that free air space at the bottom, and either insulating it, or "ducting" it (no fan) to my garage (only a wall seperates it)
I followed Erics advice on the nozzle adjust and turned them out to 6 turns cold turkey. Im not sure what it did but they have been there now for a week.
By the way-2 hours since 2nd load of trial. I am watching the water temp yo-yo slowly about 4 degrees.


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## sled_mack (Jan 16, 2008)

Don't you guys sleep?

Leaddog,
You could just use some flat firebricks to block off the back of the "tunnel" and force the gas forward.  I used the curved piece because it was there.  I added that early on, when I was having problems and on the phone daily with Zenon trying to get this thing to work.  It all sort of came together at the same time, so it's hard for me to say for sure that any one thing made a big difference over anything else in terms of getting the fire going.  But, it certainly makes sense to me that the boiler can extract more heat from the gasses the longer they are in the chamber.  How much I can't say, but I'm going to leave them in there for now.

Eric,
2 hours north of me puts you just south of Tug Hill, right?  We go up there snowmobiling a few times a year - snow permitting, of course.  Haven't looked at a map to see exactly where Clinton is.
I'll have to check out the size for replacing nozzles.  Hopefully, it isn't the bottom of my nozzle that has fallen apart.  And offhand, I can't see how they would be easily replaced.  Maybe if I see what he is selling it will be more clear.

Bartman,
The 1200 can take add-on I/O modules.  So it works for here.  The PLC you have is fine, too.  Just make sure you can get programming software and that it works with windows or you have an old DOS laptop laying around.  We had to work on an old PLC last year, and luckily, one of my coworkes had an old, old laptop laying around that still ran DOS.  Otherwise, our client would have been buying a new processor....
I've never seen thermocouples or RTDs last very long in direct contact with water.  You can usually find threaded wells for not a lot of money.  Well worth the cost in my opinion.  Welded ones are even cheaper, if you are willing to weld on your boiler.  I've welded a lot of things over the years, but I'd probably go with a threaded well on my boiler.

Barnartist,
Glad to hear the blocked nozzle is working for you.  Oddly enough, last night I was thinking it would be nice if it were easy to block/unblock that nozzle.  When we've been gone for a few days and the house is cold, and the storage tank is cold, I'd want to use both nozzles till I get the house recovered and the tank at least partially recovered.  But then how to block off the nozzle when it's full of hot coals and ashes?  I really don't see an easy way of doing it other than shoveling the ashes out and putting the firebricks in place.

I don't think there is any harm in insulating under the boiler.  I don't know that there is much to gain from it, either?  I don't think the water jacket goes down there, it's just a bed of refractory at the bottom.  How well is your shed insulated?  Mine is insulated fairly well, and it gets hot in there.  I've thought about getting some of the blue foam insulation board, 2 inch thick, and basically wrapping the boiler in it everywhere except the front.  That little bit of glass in the cover of the boiler probably isn't doing much.  And it made a huge difference when I wrapped the outlet pipe off the top of the boiler in 6 inch glass.  The tank got hotter much quicker, and the shed temp went down a good 10 or 15 degrees.  I went right over the pipe insulation that was already on the pipe with the glass.

It is possible that the tunnel I created led to the ruin of the upper refractory.  But I don't think it should have.  If I left the fire going with the fan dampers all the way open, getting super hot temps in the lower chamber, then maybe.  But I'm always keeping it as low as possible and still firing nicely in the lower chamber.

I'm not sure that slowing the fans down is a good idea.  You need some pressure behind the air.  Even though you are restricting the flow, if something at the nozzle tries to blow back towards the fan, the pressure from the fan will resist that tendency.  Again, that's just me guessing on this one.

I opened the secondary screws another 3/4 turn this morning - I'm at 4.5 turns now.  It's only a little over an hour into it's burn cycle, so I'll wait a while to go check on it.


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## Eric Johnson (Jan 16, 2008)

I'm just south of Utica, so it's probably less than 2 hours.

To block off the nozzle, you need to clear it off and put a firebrick over the top of the nozzle. Then you have to be careful not to knock it out of place when you load wood. But it effectively cuts the output of the boiler in half, so you can get a harder working fire that lasts longer and puts out less heat if your boiler idles a lot. It wasn't my idea. One of our Michigan EKO members (leaddog, maybe) came up with it. I tried it for awhile and was pleased with the results. As I learned a bit more about how to operate the boiler in my situation. I can't see what it would hurt, though you might have to fool around with the air controls to optimize it.

I think the nozzles just drop into the refractory mass. I've never seen them out of there, but that's what it looks like to me. You can replace the entire refractory mass. It's probably pretty heavy. You have to grind the tack welds off of the secondary air supply tubes and pull them out before removing the refractory.

Personally, I think you take a risk when you try to improve the efficiency of these boilers by modifying the path of the flame. I suspect they designed the refractory that the flame blows into the way they did for a reason. If you look at virtually any Euro downdraft gasifier (EKO, Econoburn, Atmos, BioMax, Tarm, etc.) they all feature some variation on the curved refractory theme. And if you look at the evolution of the EKO design in this area, it's changed over time--but it's always been a curved piece of ceramic. I suspect that deflecting the flame back up into the refractory mass is an important part of the design. And while I understand the reason for creating a design that keeps the hot gas in the bottom chamber longer, I wonder why nobody designs a stock piece that does that.

I guess ditto with the blowers. They've got variable speed fans already. Seems to me if they could easily increase efficiency by varying fan speeds depending on boiler water or stack temp, they'd do it. But I admire you guys pushing the envelope for the benefit of humanity. If I had the technical expertise (which I don't), I might be tempted get into it myself.


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## barnartist (Jan 16, 2008)

Steve, when you say you inulated the output, do you mean the few inched of the flange area? It really made a noticable difference ay? I only have about 6 inches exposed. My shed is not insulted, pretty open really. Air can blow through there. I have thought of insulating that area-is your big tank insulated? Is the heat coming from that or mostly from the eko you think?
Last night I think I choked the boiler too much as is was just enough air to keep up. Seemed like I used more wood, but I don't know if I went idle or not and it just had trouble bouncing back. I know yesterday, I started with the opening bigger like how you do. While last night I let it go from the beggining closed to a minimum. 
I like your idea too with the foam boards.


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## leaddog (Jan 16, 2008)

I used some foil/bubble/foil wrap on the top of the boiler and it dropped the surface temp something like 20f.  That was mesurments taken with my ir meter. I've been planning to do some more expermenting when I get some more foil as it looks like it might help keep the boiler temp up. I've been pretty busy helping the inlaws so I haven't been able to get to all the things I'd like to. But things are starting to get back to normal.
leaddog


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## sled_mack (Jan 17, 2008)

Well, so far no real noticable difference in opening the secondary air screws in terms of smoke.  This morning, my stack temp was up a bit, more like 225.  Still not bad.  Just opened them to 5 turns when I started the fire tonight.  Tomorrow morning I'll go to 6 and see how that goes.

I really don't want to have to replace the whole refractory.  I thought there was some steel structural support in there?  Does the full weight of the wood in the fire box rest solely on the lower refractory?  Now I'm scared!

Eric,
I hear what you are saying about modifying the gas path.  But, I'm not sure that it is that dangerous of a thing to do.  Basically, all I did was put higher sides on the U shaped pieces and block off the direct path to the rear.  All of this at Zenon's recommendation.  Having worked for OEMs in the past, I'm going to guess that they keep the refractory simple for manufacturing and maintenance reasons.  Not because there isn't a better way.

Same with the controls.  We just did a job retrofitting the controls on an industrial wood boiler.  The two primary control points are water temp and O2 in the stack.  The O2 reading is the sole calculation for efficiency in their setup.  And, the fan maintains the air pressure, but a damper controls the air flow.  The instrumentation and actuators required to really do the controls right would cost half (or more) of what the boiler costs.  (The O2 analyzer on that job cost more than my boiler, tank, pex, copper, and shed all together, and then some.)  Knowing the theory, if I could get the parts cheap, I'd take a shot at it.  But, for the little gain that is available by doing all of this, I really can't see it paying back.

Barnartist,
At first, I had pipe insulation only on the first 6 feet of pipe up to the pumps.  Only the flanges were exposed.  I left that in place, and wrapped 6 inch fiberglass insulation around the whole thing, up to the pumps.  And that made a huge difference.
My shed is insulated to at least R19, all sides and roof.  The tank has R38 all the way around, and on top.  This fall, I re-insulated the area over my kitchen in the house.  Any insulation that was usable went into the boiler shed.  Basically, I used it to stack on top of the boiler, along the front edge, and on each side out to the walls, to form a sort of wall.  This way when I open the door, not all of the warm air around the tank is able to quickly escape.  I also took some and just wrapped it around the pipes at the return manifold.  Seems to have really helped.
If you are going to insulate around the boiler, foam boards are probably better.  Glass can hold moisture and dampness.  Really, the ideal thing would be to take the covers off and have it sprayed.  But, I'm sure you'd never get the covers back on.  I'm sure you are losing some heat with that area not being insulated, but how much is the question?  
For reasons I don't fully understand, I use more wood when I lose secondary combustion.  My only guess, is that the secondary cumbustion creates back pressure on the primary chamber from the rapid expansion of the gasses, and slows the primary air flow, which slows the burn rate.  So cutting back too far, and losing that secondary burn later in the cycle, could end up hurting you.  And it doesn't take long with the fan dampers open to get good secondary combustion.  I had secondary burning in about 30 seconds tonight.  Let it go for about 10 minutes (stack temps were already up to almost 300) and closed it down.  

Leaddog,
That's a good indications that insulating the boiler is of some value.  But, I'm not sure that foil/bubble/foil is the right stuff.  After I used a bunch of this, and plain foil, in a few areas around my house, I read a lot of things that made me regret having used it.  I know it's a lot cheaper than foam, and easier to work with, but I really think foam is better suited for this application.


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## sled_mack (Jan 17, 2008)

So, I'm stuck on this pump sizing issue.

Let's say that tomorrow I turn off the heat in the house when I load the boiler.  I check the tank temp when I load the boiler, and again when the timer stops the boiler.  Now I can calculate BTUs delivered to the tank, and therefor, BTU/hr delivered to the tank.

Does that give me any useful information?

I'm not weighing wood as I put it in, or checking moisture, or burning it to completion, so checking efficiency is out of the question.  All I want to know is - would I transfer more heat with bigger pumps?

All thoughts, comments, and ideas are welcome!

Thanks.


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## Eric Johnson (Jan 17, 2008)

Are you still getting smoke during operation? You might need to take the blower mounting plate off and open the primary air channels. There are 12 sheet metal screws, and it's no problem with a drill or electric screwdriver. You need to make sure that you tighten them all about the same, or you'll get smoke leaking out from under the gasket. You also need to open both upper and lower doors to get at the screws, assuming your boiler is similar to mine. I did that early on and it helped a lot; the secondary air adjustments finished the job. Same thing happened to leaddog with his 80.

I'm sure the refractory is hanging on some sort of metal hangers. On mine, I can see what looks like a steel tab between the edge of the refractory and the lower chamber steel wall. Is your refractory mass coming apart or cracking?

When you say "lose secondary combustion" are you talking about late in the cycle when you can't see any flames in the lower chamber coming through the nozzle? I call that "out of combustible material and living on hot, invisible gasses." If that's what you're describing, I'm not clear on how you know you're burning more wood, since when that happens to me, there's very little wood left in the firebox.

If by losing secondary combustion you're talking about having nozzles that won't fire, then of course you'll burn more wood because most of your fuel will be going up the stack unburned.


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## sled_mack (Jan 17, 2008)

Eric,
Still seeing smoke.  I think I see how more secondary air is going to help reduce smoke.  More air into the secondary fire should mean more combustion.  But how would more primary air help?

As I see it here, we are trying to balance flow between primary and secondary.  Opening the primary should affect the balance the same as closing the secondary.  At least that's my take on it.  And hopefully, the fan damper adjustment doesn't affect the balance, just the flow to both evenly.  That's how it seems like it should work to me.

I've had a few pieces of refractory fall off around the bottom of the nozzles.  And, maybe it is actually the bottom of the nozzle and replacable?  I haven't cleaned it since this happened, so I'll have to clean it this weekend, and get a good look at it.  And some pics while I'm in there too!

When I say lose the secondary combustion, I mean blowing smoke out the bottom.  Remember, I run for a fixed time, not till the fire goes out.  That's why I'm suprised that it burns more wood in 4 hours if it loses secondary burn compared to 4 hours with secondary burn.  And I agree - no flame out the bottom, but just a clear gas stream and glowing hot bricks is still good heat.  That's right about where it's at when my timer cuts out.


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## barnartist (Jan 17, 2008)

I also lose secondary combustion. Usually. I can have a good nozzil fire and later in the burn it is just a clear air type cumming from the bottom. It seems to me also  it is hard to get back to gasifying if the boiler goes idle too. A simple movement of the wood in the upper chamber gets it going easy again, but who is there to do that all the time, and is it really nessesary. I know I can really extend the burn if I baby those air openings and such-but I dont wanna.
 I think I have the same eko as you Steve, and my primary air openings inside the panel were opened all the way. Like you, I really see no effect on the secondary air settings, unless run clear in. But when you look at it all while that panel is off, I cant even believe how simple it all is. By the way, some of my panel screws are stripped out and thus that panel really rattles noise. You guys have that? Also, last year when I took that panel off for the first time, I found that a layer of black paint had bubbled off so far it was choking my fans. And it wasn't creasote. If you havent been in there, might not hurt to look. I may have sent you pictures Steve.

Steve I think you have the facts in front of you about your pump flow. You have the results from before and now. It be nice if you had a bigger pump you could trade and try out to know for sure. Does your current pump change speeds- and if not what could you do with that? Id like to know as well because I may be doing some new plumbing again when I add storage tanks in a few weeks. Ithink im around 7-10 GPM on my Laddomat, but when the valve opens and lets hot out what am I really getting then. Should I add another pump for added flow? Sounds like I should. And would that then lower the stack temp. If it does then there it is.


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## sled_mack (Jan 17, 2008)

6 turns out on the secondary screws this morning.  We'll see how that holds up at the 2 hour mark.  I suppose as long as I'm not losing secondary burn, I can keep going.  True or false?

My test is in progress this morning - boiler running with house heating system shut down.  We'll see how much heat goes into the tank in 4 hours with no load on the tank.  I'm still not sure what that will tell me, but it's doesn't cost anything to get a bit more information.

But, in thinking about this, I've come to another startling realization - I may not have enough hx capacity to make use of bigger pumps.  After 2 hours of burning last night, boiler outlet temp was 190 and inlet was 183.

What that tells me (I think) is that the small pumps were not big enough to move enough heat to the tank, and the hx in the tank were not being used to capacity.  But, with the big pumps I have on now, I can remove the heat from the boiler but the hx is not capable of transferring that heat to the tank.

Scott,
You have pressurized storage, so the hx issue doesn't exist for you.  But, you really don't know what the Laddomat is putting out for flow without having a look at the pump curve.  Did you get the one I sent you for my pumps?  Head pressure has a huge impact on flow.  If the Laddomat says 10 GPM max, you can be sure you are not getting that.  I still think your system would work better with a big pump between the outlet of the boiler and the T to the Laddomat.  That pump would feed the Laddomat when it needs hot water to boost the return temp and feed the top of the storage tank (or other loads) when the return temp is high enough.  I've got to believe that the more heat you remove from the boiler, the lower the stack temp is going to be (given the same burning conditions) lower.  Probably not a huge difference.  But if the fire is making X BTU/hr and you are removing Y BTU/hr, then X - Y is all that is left for the stack.

I think you did send me pics of the inside of you front cover.  I've not opened mine yet.  Probably not going to right now, either.  The heads of 2 screws are stripped and 2 of the scews are not like the rest.  I'm guessing when it comes off, there is going to be some (well lots) swearing, extracting broken screws, and retapping of holes.  Seems like a better summer project.  I'm curious, have you adjusted your primary air settings at all?

Since I'm experimenting with the secondary air, maybe I'll just keep going till I either can't go any more or I start to see some difference.  So far, no change to the burn (visible) and no change to the ash in the lower chamber after the burn.

The other factor I haven't considered - with the secondary being opened more there is less resistance on the fan.  Maybe I could be closing the fan damper some more, too.  But, one thing at a time for now.

Anyone know how many turns those secondary screws can be opened?  Anything fall apart if I go too far?


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## sled_mack (Jan 17, 2008)

This hx issue has me thinking....

How much resistance to flow does a Grundfoss UP26-64 give to a line when it is not running?  I would think it is a lot.  Not quite like a closed valve, but really close.

The reason I ask - One of the pumps going to the tank has a T just after the outlet.  Straight through the T goes into the tank hx.  The stub to the side goes to a ball valve.  If I open that valve, it Ts into the line that goes to the house right after the line comes out of the tank hx.  

So, if I open that hand valve and the pump in the house is not pulling water from the hx, will the pump off the boiler push through the hx coils normally used to supply heat the house?  (There is another hand valve I can open so that the other end of the hx is open right to the return manifold for the boiler.)  It seems like the 4 coils should be much less resistance than the 300 ft of PEX (round trip), the two flat plate hx in the basement, and the pump in the basement.  This basically doubles my hx capacity in the tank.

In the opposite condition, when the boiler is off and the pump in the basement is pulling from the tank, that pump will have two more coils to pull through also.  Again, I'm hoping that 2 coils provide less resistance than the pump.

The only other condition is where the boiler is on and the pump in the basement is on.  No big deal there, some heat goes direct to the house without going through the tank.  No harm there.  I do that after being gone for a few days and the tank is cold anyway.

I've had pumps like this apart before.  It seems like without the impeller spinning you could only get a trickle of water through them.  That trickle is less than ideal, but I don't think it will really hurt me here.

So tell me, did I just find some extra hx capacity for free?


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## barnartist (Jan 17, 2008)

Sounds like you did Steve. Your smarter than me-I think your telling yourself through the writing as I sometimes do. I think Nofossil should think it over or heaterman.
    As far as runnung those screws out too far, it will just stop turning at some point, nothing should fall apart. If i remember too, those things are long, you can really have them out far. Id say after mant more full turns it really will not matter at all. The end of those screws is like a flat washer suspended in the free air inside that panel. Tour probably an inch away from the main pipe(s) that lets air go through the nozzils. Opening them more really wont matter the way I see it, and ive tried those things in different spots. Never could see a difference unless run almost completely in. Eric says he noticed a difference from 3.5 to 6. I could not tell, but he probably burns consistant fires better than me to read it better. Your right too about the screws and swearing. They are a poor fit and most of mine are stripped and the whole plate is noisy.
    If I tear this thing down (yet again) I will add a pump as you suggest. It would be great to be able to really crank that eko wide open if I were to get behind on a fire, and have the ability to recover quickly.


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## Eric Johnson (Jan 17, 2008)

The screws holding the fan plate in place are short self-tapping sheet metal screws, so I don't think you'll have to do any tapping and probably not a whole lot of cussing, to get them off of there.

The secondary air screws can come out as far as you can move them. They won't fall off.

I did adjust my primary air at first, when I was getting some smoke. I did it because leaddog, I think it was, said that his were closed when he received his boiler from the factory. So I checked mine out and opened them up a bit. When you think about it, all of the air going into the boiler goes through the nozzles one way or the other. If there's not enough primary combustion air, it seems to me that it would affect the performance of the burn in some way. In my experience, my boiler needs more air in all three inlets than the factory settings.

I'm still confused by your (and barnartist's) complaint that you lose gasification at some point in your burn cycle. IME, once the thing torches off, it pretty much goes for the duration of the cycle. Sometimes the wood will not fall correctly in the firebox, resulting in incomplete gasification, but that's only when I try to build a small fire & there's not enough weight to keep the fuel centered and pushed into the nozzle opening. When you start with a full loaf of wood, by the time the amount of wood in the firebox has diminished to the point where the nozzles aren't covered anymore, you're into pure-gas mode anyway.

If you generally fill your firebox full, then I'd say offhand that the smoke and inconsistent gasification have something to do with your air supply.


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## sled_mack (Jan 17, 2008)

Scott,
I'll run another test tomorrow using all the hx coils to heat the tank with the house off and see what happens.  Hopefully, I'll be pleasantly suprised.

Eric,
Obviously, I don't understand what is going on inside this thing.  My thinking is that too much primary air would cause the wood to burn too fast, creating more gas (smoke) than the secondary air can burn, and smoke out the stack.  I'm starting to get the feeling that I'm wrong on this?

Maybe I need to try reducing the total air a bit more, and see what happens.

When I first got this thing I would lose secondary combustion all the time.  Too much air, not enough air, who knows?  I had all kinds of problems.  Now that I've got a system in place that works for me, I don't have that problem any more.  Really, I think too much and too little total air can cause the problem.  With the fans open too far, the upper chamber seems to burn without the wood turning to coal and making a nice bed of coals.  With too little air, there isn't enough heat to sustain secondary combustion.  Both cause dark residue in the lower chamber and heavy smoke out the stack.  My experience only.


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## barnartist (Jan 17, 2008)

Heck, ours are wide open I think Steve. Maybe actually closing them(primary) some would help the test more. Its just that there freakin inside that panel, and those scews are undersized. You have good results the way you are Steve, I dont blame you for not wanting to dig in there. But Eric seems to have a good flame (gasification) throughout his burn. Eric, how far open are those primary air plates on your right now? are they open all the way? You may have said where they were before, sorry if I forget. Are Leaddogs wide open? You might have something there Steve about too much primary. Al I want here is to be able to leave my Eko with those fans in a good spot for a nice long burn-SLOW. If I start too closed, even with a nice flame at the bottom, it can later smolder a bit, but too open and I will have a high stack temp and thus more heat loss.


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## sled_mack (Jan 17, 2008)

4 hour burn is done.  Tank rose from 170 to 183.  So, 2700 gal times 8.34 lb/gal is 22518 pounds of water.  Times 13 for the 13 degree temp rise, and I get 292,734 BTU transferred to the tank in 4 hours, or about 73 kBTU/hr.

What does that mean to me?  I don't really know yet.  But, tomorrow I'll do it using the other hx coils too and see what I get.

The pump on the aquastat is still running, and will be for a while, so the 292,734 number isn't the total for the burn.  There is some time initially to get the boiler itself hot, and now it will keep transferring heat for a good long while to cool the boiler back down.


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## sled_mack (Jan 17, 2008)

Scott,

I know you've plumbed you boiler a bunch of times.  But, I think you need to come up with a good plan, with feedback from the guys here, and get that storage tank working.  I've got mine to where I set it and leave it there.  Heck, my wife even ran it last week while I was out on business.  So I really do have it to where it doesn't need constant fussing.  I think you can too.  Until you get the storage working right, blocking one nozzle may be a big help.  Otherwise, you need to choose between idling/high stack temps and losing secondary combustion by trying to keep the fire too low.

I too hated this thing when I first got it, but I got over that after a few weeks.  I feel bad for you, knowing the pain you are going through with this, and for how long you've been enduring it.  I'm not the only one here that has one of these working the way I want.  Once you get there, you'll be happy too.  And your wife!


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## barnartist (Jan 17, 2008)

Thats great to get all that water up like that in 4 hours, but yet what does 205K eko mean then? does your number divided by 4 hours kind of mean around 55k an hour? Im sure Im wrong on that. At the same time Im not sure I could raise 2700 gallons up that quickly-yet.


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## sled_mack (Jan 17, 2008)

73k an hour.  You got the right idea, I think you just rounded the first number down too far.

That's the thing.  You'd have to know the test conditions they used to come up with the 205k number.  My numbers would probably be higher if the tank was colder, for example.  So, if they use a huge storage tank, with cold water in it, and a huge hx, they could get better numbers.  And, they might be able to get 205k BTU/hr out of it, but might be doing it at only 50% efficiency from pushing the boiler so hard.


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## barnartist (Jan 17, 2008)

How can that number be that low from 205k. Since you run a pretty good camp there, I'll use that number as a guide as to what to expect when I add more heat storage.
I wonder what Nofossil thinks of that?


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## Nofossil (Jan 17, 2008)

barnartist said:
			
		

> How can that number be that low from 205k. Since you run a pretty good camp there, I'll use that number as a guide as to what to expect when I add more heat storage.
> I wonder what Nofossil thinks of that?



Good analysis. Do that calculation every time, so that you can see what changes actually have an impact. Were you working with really wet wood? I think there's a point at which moisture really affects the secondary combustion.

My EKO 25 seems to run at somewhere between 50,000 and 60,000 BTU/hr average. It's rated at 80,000 BTU/hr. I've hit that for brief periods, but it feels like running a car at redline.

I expect that as you get secondary combustion dialed in, you'll see much higher numbers. You should get a pretty good roar out of it, with plenty of flame from both nozzles. I think that you'd only see the rated BTUs with a whacking big pump, pretty cool inlet water, burning kiln-dried hardwood.


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## Eric Johnson (Jan 17, 2008)

sled: I don't completely understand it myself, so maybe I shouldn't comment, but I believe it's safe to say that if you're getting smoke, it's probably due to a lack of air somewhere in the system. That's usually the cause of incomplete combustion. If you're producing more smoke in the firebox than the nozzles can handle, then my guess is that the secondary air flow needs to increase. I think that too much primary or secondary air will cause overheating and loss of efficiency up the stack, but not smoke. Maybe I'm wrong.

One thing to check might be those secondary air tubes. Take a flashlight and look into each one to see if the air passages are blocked. They're little holes in the steel pipe, as I understand it. I suppose it's possible that they can get clogged with creosote and restrict their ability to deliver superheated air to the nozzles. Sometimes those tubes can break loose (they're only tack welded to the frame) and begin to back out. That will mess with your secondary air adjustment, too. I had that happen to mine and so did leaddog. Everything worked a lot better when I got it fixed.

Finally, I'd consider your air supply to the boiler. Can it get enough fresh air. Try running it with a door or window open (or something) to see if it behaves any differently.

barnartist: I didn't open them up very much, but I did slide them out 1/2-inch or so from the way they came from the factory. When you first look at those sliders, they look like they're completely closed. "Ah ha!" you say, before noticing that it's just the way they were designed. But they can be opened. All I can say is that it worked for me.


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## barnartist (Jan 17, 2008)

im pretty sure mine are open as if not even there. Maybe I should close them down some.
My nozzle tubes were as clean as can be, even as bad as ive burned in the past.
Great analogy NoFo, I could run it and it sounds like a distant jet too.


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## sled_mack (Jan 17, 2008)

As I see it, I'm running at roughly 1/3 of "rated" capacity.  What I need to figure out is this - Am I limited by the hx in the storage tank or the burn rate of the fire?

As long as running at a lower capacity is not causing, or caused by, system inefficiency, I see no reason to worry about it.  Assuming, of course, that I am able to heat my house at that capacity.  Really, it's only the coldest of the cold snaps that have caused me to have to load 3 times a day.  And even then, it's usually every other day that I have to do that.

To be clear, with the timer shutting the boiler down, I always have at least 8 inches of coals left over the nozzles.  So I'm not filling it as if the fire box were empty each time.  That's how I get the fire started so easily each time.

Nofossil,
I agree with your assement of hitting rated capacity.  Except maybe the sun and moon have to be lined up just perfect, too.  And, I think you would take a hit on efficiency doing it.  Your car will go 120 mph, too, but it will get better fuel economy at 70 mph.  Same work achieved in going a fixed distancy, but one speed uses more fuel than the other.
Tomorrows experiment will be using the other coils in the tank to see if that affect how much heat is transferred.  I'm not here every day, and I can't have the heat turned off every day, so my test runs will be limited.  Once I know more about the hx issue, I can decide on how to address the burning issue.

Eric,
Can you tell that I really don't want to take the cover off?  If I do, do I need to take off the jam nuts for the secondary screws?  Seems like I'd have to, or the whole thing would have to come off with the cover.
One note of interest - this morning was the first time I noticed a reduction in smoke.  So maybe a little more secondary air will do the trick for me?  I'll open them a bit more for tonight's burn.
Which brings me back to this - if I have to put in more air to optimize the burn to eliminate smoke, but my stack temps go up, and I can't capture the excess heat to the tank, have I really gained anything?  I don't know the answer to that question either.  Maybe I'll be able to figure it out?


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## Eric Johnson (Jan 17, 2008)

Taking the cover off is no big deal. Nothing else comes off/out. The blowers and secondary draft adjustment screws stay attached to the blower plate. It's just the 12 sheet metal screws you have to keep track of. But don't do it until the fire burns way down or is out, because you'll get smoke in your face and you need to open both doors to get at the screws anyway.

One of the main reasons I bought this boiler was to eliminate the smoke, since I live in a populated area. Really, for me, everything else is secondary. But having said that, it's a lot more efficient and powerful than the boiler it replaced.


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## leaddog (Jan 17, 2008)

Ah the air thing again--------------- I'm not sure that anyone has got a handle on this. Just what is working best for them. My take on this on how it works in a eko. There is three adj. and they work together. I have my primary air ( the one under the cover) open about 3/4 way. The secondary open 6 turns. I run the fans open from 1/2in to 1in. By working together I mean like this. If you have the primary closed smaller it will cause a higher pressure to the secondary with the same fan opening. If you have the primary opening open all the way the secondary will get less as the path of least resisance is through the larger opening, With the fan opening the same.  It seems to me that if you have to much air going into the primary chamber you tend to get more smoke as it is trying to burn there but you need enough to push the gasses down into the nozzel. It seems to be a balanceing act with type,size,moisture content and air temp all being part of the fix. That is why everyone has to kind of learn what works best. The end result is when you get the best gasifcation, stack temp, heat output, and low ash for your situation. I do wish that the air adj were easier to adj and that it would have more instruction in the manual so people didn't have to learn on there own so much. I think as there is more of these out there it will become better.
leaddog


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## Eric Johnson (Jan 17, 2008)

My approach has been to follow your lead........'dog--and set my air like you do. And it worked really well.


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## sled_mack (Jan 18, 2008)

leaddog said:
			
		

> Ah the air thing again--------------- I'm not sure that anyone has got a handle on this. Just what is working best for them. My take on this on how it works in a eko. There is three adj. and they work together. I have my primary air ( the one under the cover) open about 3/4 way. The secondary open 6 turns. I run the fans open from 1/2in to 1in. By working together I mean like this. If you have the primary closed smaller it will cause a higher pressure to the secondary with the same fan opening. If you have the primary opening open all the way the secondary will get less as the path of least resisance is through the larger opening, With the fan opening the same.  It seems to me that if you have to much air going into the primary chamber you tend to get more smoke as it is trying to burn there but you need enough to push the gasses down into the nozzel. It seems to be a balanceing act with type,size,moisture content and air temp all being part of the fix. That is why everyone has to kind of learn what works best. The end result is when you get the best gasifcation, stack temp, heat output, and low ash for your situation. I do wish that the air adj were easier to adj and that it would have more instruction in the manual so people didn't have to learn on there own so much. I think as there is more of these out there it will become better.
> leaddog



I agree - it's a balancing act.  To make it worse, it's not a static balance.  You can't put the primary and secondary adjustments in any give spot and say "the air will always be split 50/50."  It might be where the fan damper is located now, but when you change that one setting, the balance is going to change too, based on which chamber gives more resistance to more or less air.

I also agree that too much primary air will lead to smoke out the stack.  Maybe I WILL have to get in there and see where that adjustment is at this weekend.....


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## barnartist (Jan 18, 2008)

Leaddogs got me thinking I also need to try a different primary adjustment. I usually always have smoke of some sort, unless in the last 3rd of the burn or so. Do you guys lose your smoke as soon as you have gasification started?


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## Eric Johnson (Jan 18, 2008)

Any smoke usually disappears within about 15 to 30 minutes after a cold start. When there are coals on the nozzles, sometimes there's no smoke at all on reload. I do get vapor when it's really cold.


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## barnartist (Jan 18, 2008)

So if I have a nice coalbed start, and good flame below, I really should see nothing then?
Well, I had to tinker with the primary, and here is whats happening so far. I definately have a much bluer flame out the bottom. I think the color blue is the hottest color. I could really feel the heat hit me. What happend (so far) is that I needed a bigger fan opening to keep the flame going. So, my stack is about 50-75 degrees higher-around 375-400. I was afraid to close the fan more than one inch or I might lose the gasification. So now it leads me to Steves original post Q- Am I getting enough water flow out of the boiler. Keep in mind to that I am using only one nozzle. Now all of this could mean nothing in the morning when I see more results-ash, water temp, so forth. Im watching my water temp, and I raised it about 6 degrees in maybe 15 minutes. Took a shower-long and hot, and it seems to be just holding steady. Now I am wondering if I lost the flame or not.
Man, these things are so tricky. At some point will we not have a EKO/Gasifier Bible? I hope so for the next guy. I still think we are in the book of Genises.


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## barnartist (Jan 18, 2008)

On a side note; tomorrow I start unhooking my cousins gaser and hook up a Central Boiler. Another post I feel...


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## sled_mack (Jan 18, 2008)

Eric,
Just to be clear - no smoke means no visible emmissions from the stack.  I still get this whispy gray smoke that dissipates within 15 ft of the stack, even this morning when there is no breeze.  In the past, I've gotten up on a ladder, and it is oderless as well.  Is my wood wetter than I think, and this is water vapor?

Scott,
Which way and how much did you adjust your primary?
I've got two big pumps pulling the heat from my boiler, each of which is probably moving double the water your laddomat is moving.  I think you may have an issue there with that setup.  Have you posted a sketch of your setup to these guys here yet?  I know what I think would help, but I'd like to hear some other opinions on it as well.
How is it working out with the one nozzle blocked?  In theory, it should burn twice as long.  But practically, I'm guessing the wood at the other end of the firebox isn't going to fall into the coals and keep burning.  It would make for a really easy start to the next fire pushing that dried wood into the coals and putting more on top!

Hooking up the CB should be a snap.  The biggest issue will be how close it is to where the EKO was.  Once the pipe and wireing are there, hookup is quick, filling with water can take a while, then fire it off!  Good luck with that.

Second tets is in progress here.  Tank was 172 this morning, it was 169 yesterday.  So, we'll see if we transfer any more heat using the extra coils.  3.5 hours to wait....


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## Eric Johnson (Jan 18, 2008)

That could be. I'll get that with wood that's not as dry as I'd like. I get a fair amount of vapor when it's really cold, too. I'd say if it dissipates within 15 feet and is odorless, then it isn't smoke.

I think Scott said he cut his wood last spring. It's probably not completely dry, which I think might be part of his problem. Wet/green wood won't gasify easily, and won't stay lit, either.

I've reluctantly decided that everyone who burns wood should have a moisture meter (which I don't). It's kind of like driving without a speedometer.


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## sled_mack (Jan 18, 2008)

Eric,
You may be onto something when you said it takes a whilel for these things to react to changes!  I've made no adjustments since yesterday (to keep things the same for my hx test) and this morning there was no visible smoke when I looked out about an hour after starting it up.  2 hours into the cycle still no smoke.  I went out and took a peek - the lower chamber is still burning nicely and stack temps are around 250.

I hate to jump to conclusions half way through my hx test, but....  The tank is up about 9 degrees in 2 hours.  It was only up about 5 at this point yesterday.  I'll be keeping my fingers crossed that this is really going to be better after 4 hours.

And, since I burn based on time, and the time is such that the boiler never goes idle or empty, and the air adjustments are the same as yesterday, this may mean I can capture more heat per load of wood, too.  We'll know in another 2 hours!


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## sled_mack (Jan 18, 2008)

Well, it seems I have enough pump capacity and not enough hx capacity  Just checked the end of my 4 hour burn.  Tank is at 188.  That's up 16 degrees, 3 more than yesterday.

And to be fair, the hotter the tank gets, the slower it wants to heat up.  And, at those tank temps I noticed the boiler went into idle mode.  Not sure when, but it was idling at about 3 hours and 45 minutes.  That really limits the rate of heating the tank, too.

To be fair, I'd have to repeat this test next week, trying to start with the tank temp down around 160.

Two points of concern -
First - the pump off the boiler did manage to push through the pex, pump in the basement, and the two flat plate hx in the basement.  I closed a valve in the basement to get a fair test with no losses to the ground.

Second - with the path the way it is in the boiler shed, the basement pump can either pull through the coils in the tank or pull through the boiler.  They are essentially in parallel.  Check valves won't help, because the water is always flowing the same direction.


The first problem I can solve with a valve that opens only when the pump runs.  (Any recommendations on a good 1 inch valve to work off of 110 VAC?)

The second problem is a whole lot more difficult.  I didn't plan on adding an automated valve there, and I have about 4 inches to work with.

Here's a thought - Does anyone make actuators to fit on the stems of 1 inch ball valves?  I know for larger industrial valves it's easy to get actuators that just fit on the stem.  No need to replace a valve when you want to automate one.  That would make my life soooo easy!


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## barnartist (Jan 19, 2008)

The more I read your flow post, the more I need more flow here. I dont even know what an actuator is. Sorry cant help with that.


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## barnartist (Jan 19, 2008)

Well, I had really bad results closing the primary air sliders to about 3/4. This morning my tank was really cold, and the eko shut down out of wood. I havent had that since last year. Im not sure what it means. Must have burned really hot and fast to use up all that wood and not have much heat left in the tank. My tank has not been that cool for a while, and man did I have trouble getting things stable again. I am thinking not enough water flow, 6" stack instead of 8" chokes it some, and maybe the wood selection was soft stuff, but i tried to mix it as I normally do. Right now im into my best wood. 
    Add to that my trouble restarting. I am thinking with my house pump running continuous, maybe it keeps the Laddomats valves from working the way it should. That pump (011 taco) sits about 5 feet from the top of the Eko hot supply. Maybe it overpowers those Laddomat valves.

Eric, once you have gasification started from a new fire, you say you never lose that till the load is used up? I know dry wood is best, but im confident my wood is pretty good, but with no meter only a guess. And reading Nofossils findings on 30% wood......

Im a bit worried about adding storage, but im going to try it with yet another plumbing scheme. 

Steve, how often do you need to clean your rear tubes? I am also pondering eliminating the Laddomat, go with a termovar valve that I have, and move my biggest pump (011)to the Eko loop-and move up to 1 1/4 pipe. Feed the storage tanks with an option to feed the house if I get behind. Something is making cold starts too hard, and something makes me eat wood.

 The End - sequal later. Sorry for the long one, but this is sort of a hard record to look back on too.


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## Eric Johnson (Jan 19, 2008)

In my experience, it takes at least a year to get really dry wood. I think one of the symptoms of trying to burn wood that isn't sufficently dry in a gasifier would be hard starting and inconsitent gasification. But you won't know until you put a meter to your wood, so it's all a guess.

I think the 6" chimney is a major cause for concern, especially if your boiler is producing creosote, which is probably a combination of poor draft and non-dry wood.

It's hard to diagnose anything from 800 miles away, but I've burned wood for long enough to know that spring-cut wood is generally not dry. It burns better than green wood in a stove or conventional boiler or furnace, but when you get into gasifiers, I think all bets are off.


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## barnartist (Jan 19, 2008)

Your right. I need a meter. Tell me where to order one for 20-30 bucks. Had a buddy tell me by the way, he had a piece of wet wood he brought in, caught the water that came off of it for one day.... one gallon of water. I did not try it so who knows, but man.
What do you think of the flow thing Eric? What size of pump you runnin over there?


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## Nofossil (Jan 19, 2008)

barnartist said:
			
		

> Eric, once you have gasification started from a new fire, you say you never lose that till the load is used up? I know dry wood is best, but im confident my wood is pretty good, but with no meter only a guess. And reading Nofossils findings on 30% wood......



For my part, gasification combustion never stops. It even has a little flame during idle.

For the record, 30% wood looks and feels really dry. All of it was cut a year ago or more. Most of it has been stacked covered for over a year. I was surprised at the readings. I had some locust that was cut down in 1998, and has been cut to log length, split and stacked for the last six months at least. seems dry and hard. Still 30%+.


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## Eric Johnson (Jan 19, 2008)

I've got a Grundfos 26-96 pushing through a 200-foot 1" loop. I also have a 3/4-inch line being circulated with a Taco 007. It's only a 100-foot loop. I'm thinking of putting a three-speed on that one, just to have one more thing to play around with.


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## sled_mack (Jan 19, 2008)

Scott,
I forgot now - did you open or close the primary adjustments?
Before replumbing, put some sketches up here for comment.  Keep in mind, I don't have any automated mixing valve.  Not saying they are a bad thing, but it can be done with a hand valve, too.  But, my tank never goes below 160 during normal use, so my return water is never in danger of causing condensation problems.  And if the tank is down below 160, I get it back up above that pretty quickly, then close the valves.

In my experience, if the wood isn't totally dry, smaller pieces are better.  Try a few loads where you split the wood smaller.

The actuator is the electrical device that sits on top of the valve body and makes it open and close when power is applied to it.

How did it go with the CB today?


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## barnartist (Jan 19, 2008)

C.B. installed and really simple. I have to say, so far I am liking what I see from it, but we'll see how much wood it consumes. Myself, my cousin, my dad, and probably my daughter could fit in it. I have to also say how little smoke comes from it at idle. I get more smoke I think. Believe me I'll keep an eye on it.

I am into really good oak right now Eric. Did the old smack two pieces together and it sounds like I hit a grand slam. Nice hollow sound, but no real number to that I guess.

   Before I had an automatic valve Steve, I had real problems from a cold start. I think I'll be ok by either adding a pump like you said in the eko loop, unless someone here thinks the Laddomat's pump would choke the flow from the added pump. If so I will switch to the termovar valve and eliminate the Laddomat. Maybe the Laddomat should be used on smaller sized burners, I don't know. Maybe I should post a new thread about the laddomat, see if anyone else is using one...? This is suppose to be Steves thread, maybe I hijacked it.


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## sled_mack (Jan 20, 2008)

Scott,
I don't mind the hijack, but you'll probably get more visibility on your question in another thread.  Start a thread, post up a sketch of what you have and what you want, and wait for the feedback and suggestions!

If all goes well, there should be some pics here.  A few of the tank and plumbing setup from when I installed everything and a few of the lower chamber from today.  You can see how I have the tunnel setup and where the refractory has broken apart a little around the bottom of the nozzle.  I also noticed some around the sides, too.

Edit - running into file size limits.  More pics in next post.  Home made turbulator on this one, too.

And, the U shaped pieces are in pieces.  Each one is in several pieces, but they stack together tight enough to stay in place.  I'm going to have to get some refractory bricks and just do the tunnel with those.


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## sled_mack (Jan 20, 2008)

More pics.

Hopefully, the ones of the lower chamber clear up the questions about how I have that tunnel setup.


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## wdc1160 (Jan 20, 2008)

how many ft in your HX.


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## brad068 (Jan 20, 2008)

Sled-Mack Daddy, I think you need some new refractory.  I would be a little nervous throwing wood into the firebox. It looks like it wouldn't take much to knock the nozzle bigger. :grrr:


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## sled_mack (Jan 20, 2008)

Each "nest" of coils has two coils.  The inner coils are supplied from the boiler, the outer supply the house.  Each of those coils is 60 ft of 3/4 tubing.  However, I just found that I get much better results by pumping through both sets while burning.  I just need an actuator for a valve so that I don't have to close it when the pumps go off.


I didn't empty all the ashes out the top, as they were still red hot.  But the area around the nozzle still looks good up above.  Even the nozzle itself looks fine from the bottom.  If it falls through, I'm screwed, and panic will start shortly thereafter.

Anyone had to replace that lower refractory on an EKO?  I'm curious how hard it is to do.


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## leaddog (Jan 20, 2008)

Thanks for the pic's. I think I won't add the fire brick after looking at yours. It looks to me that you are getting errosion from the hot gases . My gasses don't seem to blow back up like it seems it is on yours. I don't think that the bottem fire brick is make of as high rated  as the nozzel is as the nozzel doesn't show hardly any wear. The top of mine doesn't show any wear like that. But then I've only been running it this year.
I see that your tank is made from fiberglass. Do you see any problem with the high temp?
leaddog


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## Eric Johnson (Jan 20, 2008)

I like the tank. I'm confused about the chimney. I'm a little shocked at the refractory.

I hope those firebricks on either side of the gasification trough aren't holding the refractory up. I think we discussed inspecting the secondary air tubes to make sure that all is still well in there. With that much apparent degradation to the refractory, I'd be worried that the tubes are still delivering air correctly.

Why don't you just buy new trough bricks, instead of screwing around with all that firebrick? I'd be worried that using a non-standard configuration down in the gasification chamber would change the dynamics of the heat transfer and possibly result in either poor performance or damage to the boiler. I think you said Zenon advised you to do it this way (and that's good enough for me), but I still don't understand why you didn't replace the degraded U-shaped blocks with new ones.


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## kuribo (Jan 20, 2008)

how old is this unit????


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## sled_mack (Jan 20, 2008)

I still have the stock U shaped pieces under the nozzles.  Before I added the extra bricks, the flame would shoot out over the sides of the U shaped pieces, which would seem like it would cause more erosion on the upper refractory?

The tank is holding up just fine.  It came out of an old printing factory where they had hot oil in it.  I think it was a resevoir for a piece of hydraulic equipment.  It has shown no signs of degredation from the hot water.

It's not all that clear in the picture, but when I stick my head in there I can see a definite difference between the lower refractory and the next layer up where the air holes are in the nozzles.  The bricks are not touching the top refractory, so I know they are not holding it up.

I may still buy some new U shaped blocks.  However, I still do like the fact that what I have brings all the hot gasses to the front.  This extends the burn time in the lower chamber and gets a bit more dwell time of the gasses on the side water jacket.

When I told Zenon last year that my U shaped pieces were falling apart, he was the one that actually recommended against buying new ones.  He suggested I use wider bricks (so that they would stand on their own), or cast my own refractory, and leave the trough deeper and wider under the nozzle.  He says that creates a better burn.  I'll send him the pics of my lower chamber, and see what he thinks.

The whole setup is in it's third season.


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## Eric Johnson (Jan 20, 2008)

That's interesting about the bricks. Seems like it would be pretty easy to cast your own, though I don't know about firing it, but I guess anybody with a kiln could do that. It would be nice to get a set of plans for building a mold in the optimum shape. Sounds like a fun project.


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