Oil burner combustion adjustments

Leo

Is the burner fan clean? Something often overlooked, if dirty you have to open the air to clean the flame. Is the burner flange tight and sealed? This unit should get around an 81% combustion eff, and around here that nozzle is the one most often used. I am assuming it has an AFG burner?

Leo

Unknown

Occasinally I come across an oil burner thats giving me some strange readings. Let me share with you some of what I find in the hopes of finding a better way of adjusting.

Case study #1

- Efficiency 69-72%

- .85gph nozzle @ 100psi in a boiler rated for 1.00gph

- Gross stack temp approx 550-600 F

- Excess air 120 - 150%

- CO2 5.5 - 6.5%

- CO 1-4 ppm

- Zero to trace smoke

If I could get the CO2 up I can boost the efficiency. The fire is set with just enough air to go from a trace of smoke to zero. Any less air and the fire is sooty. Generally the more I close an air shutter, the less excess air I see, and a higher CO2,.. this one I cant close the air any more than it is already, but my excess air is way to high and CO2 way too low.

Any suggestions?

This is a Weil McClain 68 series boiler, the flues are completely clear,.. the fins in the flues have actually worn down dramaticly in the damp dirt cellar environment. That is whyI am seeing such a high stack temp,.. the heat from the flue gasses zips throughthe flues too quickly.

In general,.. whats a good way to bring CO2 up?

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Todd_16

Excess air

Maybe there is some air coming in between the sections?

Unknown

Its a model A (larger bladded fan) And the fan is clean.



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steve_29

Check your blast tube and burner head.

Make sure cleanout cover has tight seal , replace Kaowool if hard or broken.

Leo

If

If you are using a solid nozzle try a hollow. Try an >85 80 A. Are your draft readings with in mfg specs?

Leo

lee_7

sounds like you are on the opposite side of the curve. my old boss taught us that the readings are like a mountain. readings look ok but thanks to electronic testers we can see excess air. you state you can't close airband any more-- is it completely closed or can't close to to readings? there is a point that opening are band will make better readings and then open a little more and readings get worse. close air band completely and start setting up unit. Also, how is your "z" dimension. Have seen many that tech accidently removed nozzle bracket plate, put on ground and reinstalled upside down. Done this myself. took 3 hours to figure out what i did. what an eye opener. if I remove plate, I always mark outside of plate and mark location on side of burner.
Hope this helps

Robert O'Brien

How

about the secondary air? That round disk on the lower left of burner mounting plate?

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EBEBRATT-Ed

Isn't the model "A" an old slow speed burner??? That boiler would have an AF or AFG. What burner do you have??
The pins eroding will cause a high stack temp which you should not have as you are underfiring.

Low CO2 is bad combustion. Wrong nozzle, wrong oil pressure, wrong burner or wrong parts in burner, bad combustion chamber Also what is the draft?? To high a draft will pull in excess air and lower co2 if the boiler is leaking air betwen the sections. To much excess air will raise the stack temp also.

Sounds like a job for new equipment

Ragu_5

Just a thought...

Yeah, it may be time for new gear, but I've bought some time and raised the CO2 a couple of points by bumping up the fuel pump pressure by 10-15 PSI. Worth a shot. Good luck.

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[Deleted User]

That burner probably has

an F6 Head. If you are going to keep it, & fire @ .85, you might try an F3. The static plate should be OK.

Unknown

There's a lightbulb!
Ive checked Z dimentions, secondary air, draft is normal, and all that, but I never thought to check the end cone size.

Thanks for the tip, I cant believe I overlooked it.


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Steamhead (in transit)

On a 68 series boiler

the Beckett "A" or "AF" will not produce enough static pressure to keep the boiler from sooting up. Even though the pins are worn, you really should upgrade to a Beckett AFG, preferably with the newer M-type air tube and head, or a Carlin EZ or Riello. This will make a world of difference.

"Steamhead"

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chapchap70_2

Assuming you took the CO2 readings at the breech, what is the CO2 reading over the fire?

J.C.A._3

Norm,

I've tried to email you something..but it keeps timing me out.

Hit on my email, and I'll try to send it without being timed out. Chris