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
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.
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?
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.
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.
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.
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.
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.
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.
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
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.
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?
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.
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.
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.
