Questions on power burners, CO production and other things

Dave Stroman

Mark, you are making me nervous. I have many Buderus boilers out there with the Carlin G3B. They all work great. I always thought they were good only up to 180,000 Btus. Very quiet. Chris Rourke (sp) says they are one of the best kept secrets. The Riello, on the other hand, you can hear it from the street when you pull up in front of Low Energy Systems (a local supply house). I attended a class the other day about the Bock water heaters who use Carlin burns. I told the Carlin rep about our use with their burns on the Buderus boilers. His words were that they were never intended for use on those type of boilers. They were made for oil burner replacements.

Mark Eatherton1

Follow up to last weeks problems.

Greetings all. Let me first thank all that responded to my questions last week about the Carlin burner problem on the Buderus boiler that I posed. Short answer to long question, Carlin is not universally approved for application on all Buderus 3 pass boilers. Whooda thunk!

If you're in the market for a slightly (100 hours on one and 74 hours on the other)used Carlin G3B power burner, contact me at markeatherton@hotmail.com and I will make you a smoking deal.

I was wrongly under the impression that Carlin burners were approved for use on all Buderi boilers. Not so burner breath. They were only approved for use on the 115 boilers.

In my ignorant bliss as it pertains to power burners, I overlooked the critical value of "over fire draft". You see, these two boilers had Field power venters on them, and they had never been properly adjusted. The adjustable dampers on the power venters were setting at 100% open. This was causing the barometric dampers to stand at full mast like a 6 year old on Viagra. I had been told that Carlins needed to see a slight negative pressure in the combustion zone, and seeing the baro-dampers bouncing along as they were, I assumed that there was negative draft over the fire. There was, to the tune of -.08" W.C. I made the long laborious crawl to the inducers (numeroous times) and adjusted the dampers until they were eventualy 90% closed. I ended up with -.03" over fire, and -.02 at the breaching. Good enough I thought. The burners were lighting off nicely with no woofing or back firing. I thought I had the problem solved. Then the HO called me back to tell me that they were now backfiring again on cold start. In my frustration I called the Carlin factory, and they were very helpful. They said they'd review thier Buderus records and get back to me. They did. They told me that the burner was not approved for use on that boiler and kindly asked me to remove them from service. I was serioulsy bummed. By this time, I had about 2 days worth of installation and set up labor on the job.

Fortunatley, I hadn't thrown his Riello burners into the dumpster as I had done in the past. I took the Carlins off and reinstalled his Riello 400 N burners.

Crow sandwich anyone?? Ya know what whine goes great with Crow sandwiches? How about "There's no one around here that knows what to do with these Riello burners!" How's that for a great whine... So, I find myself surrounded by cold, flameless boilers and LOTS if used burners. SO I did the best I could do. I called a local burner company (Killam Gas Burner Co) who generally speaking doesn't deal with these small residential burners. I spend about an hour talking to Leon who is quite knowledgeable on all power burners, telling him of my woes, asking him for his advice. He tells me I'm on the right trail, that Riello power burners work best with slight back pressure, and that getting the substantial negative pressure out of the combustion zone was the first and smartest thing I could do. Unfortunately for me, it was the last and dumbest thing I did. Anyway, I remount the forlorn Riello burners, adjust them to factory recommended start up specifications. THe burner starts out on low burn, and then ramps up quickly to full burn. It blows itself out, causing my sphincter to do the mamba. My mind keeps flashing back to the boiler breaching turning itself inside out in a blue flash of flame on the last on I'd worked on... My body keeps saying "RUN YOU FOOL", and my brain keeps saying"You gotta get a handle on this situation and get this problem straightened out or you'll be eating crow sandwiches for the rest of your life, witout whine..."

So, I closed the air gate way down to get the burner to fire and hold loing enough for me to be able to get a stop watch on the gas meter to see if I'm anywhere near where I'm supposed to be as it pertains to fire rate. To heck with the fine tuning, I just need the flame to stay lit long enough for me to get a handle on things. It did, and to my shock and awe, it was taking on about 500,000 btuH. That's a little out of line for a boiler with a net output capacity of 300,000 btuH. I quickly adjust the gas pressure downward and get it to within 2 % of where it's supposed to be. I then begin adjusting the air gate to fine tune the combustion process.

Unfortunatley, the only flue gas paramters that Riello gives in their manual is for CO (less than 400 PPM) and CO2 (less than 10% recommended for natural gas).

My questions pertain to Riello and Carlin.

1. What is the optimum excess air?
2. What is the optimum CO (air free)
3. What is the optimum O2
4. What effect causes excess CO production, too much air or not enough?
5.What is the effect of having too much CO2?

Does anyone know of a book out there that has this information available?

Always willing to learn...

By the way, the customer bill won't be indicative of my learnign experiences.

ME

Alan R. Mercurio

Mark, Here's a link that might give you just a little more information. It does not go into detail but there are a few things on their chart that may help.

When you get to the page just look at the menu to your left select the gas burner you want info on when that appears then select the buren in the top left shaded area for the charts.

Riello Products

If you would like I can also e-mail you an old research paper written by Riello?

Your friend in the industry,
Alan R. Mercurio

Oil Tech Talk

Firedragon_2

You didn't mention why

you didn't, but why not call Riello? It is their burner, right?

I've got a book out on Riello oil, but the gas book is about 8th in line to do, sorry Mark.

Call either of these numbers on Monday starting with this one first: 1-800-4-Riello and ask for Doug Collins.

Then, if that doesn't work ring the big guy's bell, Jim D'Anthony, RIELLO US, 410-549-1408.

Alan R. Mercurio

Now why didn't I think of that?

Mark, Jimmy's e-mail is: jdanthony@rbna.com

Doug's I guess would be dcollins@rbna.com

Your friend in the industry,
Alan R. Mercurio

Oil Tech Talk

Terry St.james

Over my head

I have been reading alot of the stuff you guys(and gals) have discussed here. I have to admit on many of the Q & A I am way over my head. I always enjoy leaving a job knowing that I have done well. Also live in an area(Montreal) where many old and new systems still thive. I am okay with the easy stuff but have been stumped many times. I work with a wonderful old jewish guy(from Hungry)that's 83 years old and still not slowly down. Have learnt alot from him and has the patience of a saint. I own a few of Dan's book but would like to get into a course via computer or other source to upgrade myself to the level of most of you guys. Any leads? or can someone point to a place to learn more.

GW

bummer Dude

That stinks, Mark, now I don't feel as crummy about nuking a guys oak floor today with 212 water and leaving a nice shade of orange peel white.

You may want to talk to the NCI people, Jim Davis knows this stuff. I call him often and he is always eager to help.

IMHO, you get the 02 as low as you can while keeping the CO below 100. 0s and Co2 have a direct relation. Make sure you don't cross that spooky line I can never remeber the name of...

High CO at light off means one thing(s), at shut down means others. Multi burner atmospheric burners almost always will give you different readings, sometimes varrying greatly, because of the air dooor theory.

Don't worry about the air free CO, it's not gonna help anything, just get the actual and stay below 100. I believe the laws let you stay below 200. Rising CO is a problem, and so isn't dropping 02. Excess air, in my humble thinking, is also gonna show up in the 02, too much 02 means too much excess air, you can slap goop at the burner mounts and doors, but for proper combustion it may or may not be productive, depends on what the readings are, and how you're adjusting the air gates.

There's lots of cool stuff to learn, I've been to CO class 3 times, I've learned lots of good stuff about combustion. The scary thing is when you learn some stuff, then you can see behing the scenery a little better.

I'm still learning, kinda neat stuff.

Gary

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

GW

CO

Too much is deadly, kinda have toi be careful. It makes me nervous when I get high readings, but there's always a reason why.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Mark Eatherton1

Time with Jim Davis...

NCI is coming to town in two weeks, and I will be there for three days. I hope to tap this gentlemans wealth of knowledge, and will share it with you all once I've gotten all knowed up myself:-)

Thanks for all your comments.

ME

Mark Eatherton1

Specific approvals only...

According to the guys I spoke with at Carlin, it was only tested and approved on the 115 series boiler. I was running it at the top of its capability. The boilers on this job were grossly oversized and I was trying to down fire them to a reasonable capacity. The system has a Logomatic 2107 control, so I wasn't too worried about condensation production.

Didn't mean to alarm you Dave. Based on the information I got from Riellos web site, it appears they will bring training to us provided we can come up with 12 people or more for class. I'll be talking with Eric the Red on Monday to see what he can put together.

Are you doing combustion analysis of the boilers at time of commisioning?

ME

Mark Eatherton1

Thanks Alan (NM)

ME

Dave Stroman

Most of my installations have been the G215 5 section boiler. Our buddy Dennis Bellanti claims that you need the 5 sections if you are firing it at it's max of 180,000. Yes, I have a comb. analyzrer from UEI. Works great. I can get the CO down to almost zero but with very hard light offs. Cut the air down to about 20 ppm on the CO and it smooths things right out.
Most of the boilers I have installed lately have been the Trinty. Copy of the chipmunks, errr, I mean the Munchkins. I have 3 in now with plans for 3 more. They all work fine. I have always been a "high mass" type of guy, but when you can walk down the stairs with one of these condensing babies over your shoulder and hang it on the wall it makes me wonder why I stuggle with those big half tonners.

Glenn Harrison

Mark, I just attended Jim's class about a month ago &...

all I can say is it will open your eyes to combusiton and CO like nothing else will. Just make sure you bring a very open mind, a good sense of humor and your combusiton test equipment to use in lab, because you will be taught some stuff that goes against many things you know, why they work, and then get to prove them in the lab.

Have fun and learn alot! I know I did.

Glenn

bob_25

Yo Mark

the subject you want to research is what I call stoker-metrics but I think the more learned call it stoichiometry. If I remember correctly, for nat gas 12% co2 and as little excess air as possible is ultimate. From my experiance I think 10% co2 and 10 to 15% excess air works better. I found firing at altitude is tricky. The Mfg. claim you can fire at sea level rate when you have a power burner. Theoretically thats true. I have had problems when the owner on the job requires factory certification that the boiler is firing at design. The factory rep sets it up for sea level input and the thing jumps up and down and randomly locks out. Then comes the burner rep he screws around for a couple of days, Fed-x's some "special parts" from the factory and pulls a **** Nixon declares victory and leaves. Two days later no heat. A boiler that isn't reliable ain't worth much. I let the reps sign off and then I set it up my way. I adjust a burner just like the carburator on my Husquvarna, then I get out the shake bottles and check it. I have a theory of why all the problems. At 10,000 ft. you would derate an atmospheric boiler 40%. To fire it at sea level input you have to force feed it. Now to get the same amount of air by "weight" into the boiler at 10,000 ft.as sea level you have to move 40% more volume through the boiler. We compensate for this when we size flues BUT does the boiler Mfg. increase the size of the flue passages in the boiler.....NO. Just my take Mark. Good Luck , bob

Mark Eatherton1

I agree Robert...

One manufacturer claims it is possible to force feed the boiler. The other manufacturer claims it has to be derated at the same rate as an atmospheric, and even another manufacturer claims that derate should be done at 1/2 the atmospheric capacity.

Riello has a chart showing exactly how much the fire box is limited to based on back pressure created by the burner. They understand an increase in volumetric flow equates to an increased pressure drop. These boilers had all but the 3 piece segment bypass baffles pulled and it STILL had a back pressure of +.16" W.C.

I set it up the way you would. Excess air less than 20% (15 actual) and ended up with 9.8 to 10.2% CO2. 02 was around 2 to 4 percent. I'm just wondering waht the effects of running the flue gasses at CO2 over 10% are. Will the flue pipes become carbonated???;-)

One other thing that bothered me about the Riello set up instructions was that they asked for a gas pressure of 1" W.C. at the manifold tapping. What they DON'T tell you is that the 1" pressure neeeds to be added to the residual blower pressure in order to get a net 1" W.C. pressure.

With the Dwyer manometer I had, I could see a residual pressure of just under an inch with just the blower on. If I set the manifold pressure for one inch, my net gas pressure would have been lean, and thats when the Riello likes to turn the breaching inside out right in front of your eyes. NOT a fun experience.
Thanks for the info.

ME