Jim Davis..please answer

eleft_4

Jim, Which would you recommend, to do, after a steady state is established. Favor a higher efficiency number or a lower CO ppm number?

And how is the overall performance effected by the CO ppm at light off?

thank you in advance, al

Robert O'Connor_6

Maybe

Rudy from Bacharach can give some insight into this. I am especially intersted in the oil side of the picture.

Regards,

Robert
ME

Mark Hunt

Hi Al


Jim must be away, so I'll give it a shot.

No more than 100ppm on start-up. 50ppm max during run(must be stable), and CO must drop on shut-down.

CO levels are more important than efficiency, however, if it's burning and venting correctly, efficiencies should not suffer.

Hope this helped.

Mark H

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

eleft_4

Thanks Mark

Check email

al

Jim Davis

CO-Efficiency

Went to Kings Island in Cincinati and got beat to death but I am back.
CO on oil is considerably different than on gas and I think your question is based on oil as it was asked in another post.
There are 3 CO readings on oil. Start-up/Run/Shutdown. In my CO manual we say that all three numbers must always stay below 100ppm. Normally the highest CO readings(over 1000ppm)have occurred when underfiring and overfiring. The one exception is between a #4-#6 smoke where CO has shown a tendency to disappear. Years ago I submitted this information to Brookhaven Labs and discussed it with Tom Butcher and he said it was logical. All other readings on oil that are above 100ppm are signs of mechanical problems that must be addressed before any attempt to raise efficiency can be accomplished. I have a sequence of 14 different senarios of CO readings(Start/Run/Stop)that indicate different problems. Some of these would be:bad nozzle, bad nozzle selection, air in the oil, bad cutoff, misaligned drawer assembly, poor electrode setting, cavitation of oil(two line system), too much air, too little air, dirty, poor cutoff etc. Once the CO numbers on oil have been mechanically controlled, they are not influenced that much by our final efficiency adjustments. The final efficiency adjustments are then determined by Oxygen, Temperature and Smoke.

Robert O'Connor_6

Jim

Thanks for answering this post . I am very intersted in this subject also.

Is this info published somewhere we can purchase it?

Do you offer oil specific training?


Robert O'Connor
ME

Robert O'Connor_6

delete duplicate post

Jim Davis

This information is in the manuals I use in my training sessions. In fact I am working on a new, more complete diagnostic chart for oil, that will show each CO reading and then the possible O2, Flue Temp and Smoke # that would accompany this condition. Because of the amount of background information that is needed to understand how all these numbers came about, we have nevered tried to just sell the manuals alone.

jim sokolovic

What? How???????

Jim, last week we discussed the unpredictability of CO versus a known CO2 - there was general agreement on this, or at least we shared and learned some things. How in the world are you going to provide flue temperature and smoke values based on CO alone? Can't CO exist under almost any circumstance (clean/dirty flame, rich/lean mixture, over-fired/under-fired)? I would have thought you to be against this type of generalization? Will this chart be shown here?

Jim Davis

Jim-
The oil CO curve is nothing like the gas CO curve because CO on gas equals Smoke on oil for efficiency adjustments.
On oil,with the exception of overfiring or cutting back air too far, most CO numbers I am trying to define will occur with zero smoke. Here is a sequence of numbers I am referring to:
CO-Light-off= 70ppm
CO-Running = 40ppm-45ppm-50ppm-55ppm(rising)
CO-Shutdown = 300ppm
With this set of readings you can adjust fuel and air until the Cows come home or whatever your customers name is and it will not go away. It has to do with mechanical deficiencies, not fuel-air ratio. And then people say how can you spend a whole day on just CO. Actually I wish I had two.

jim sokolovic

The use of CO numbers...

taken at startup / running steady / at shutdown, for purposes of finding the mechanical problem on oil-fired equipment that you are promoting sounds intriguing and feasible (if these numbers indeed are repeatable). I do not have the overall experience to say, for sure. But I still don't see how you are going to equate a flue temperature to these numbers, or even understand the point of trying. If a guy has a CO meter, wouldn't he certainly have a temperature gage or thermocouple built in the probe? I guess if the CO numbers that you define occur at a zero smoke, then you can correlate a smoke reading to them - it's zero, right?

Jim Davis

CO-Smoke

What I was initially saying is that most unacceptable CO reading can occur at 0 smoke, but that does not mean that it is zero. CO & Smoke are almost totally independant on oil and fixing one doesn't necessarily affect the other. Just received a call an hour ago where an oil burner is producing these CO numbers with zero smoke: Lightoff-200ppm Run-100ppm(stable) Shutdown-1500ppm. This is most likely a poor nozzle selection-pattern/angle. Oxygen & Temperatures are in the proper ranges. Adjusting air or fuel makes little difference in the CO readings but do affect smoke. In a short post I know this may sound confusing and trying to make sure my new diagnostic form addresses this as much as possible is straining my brain. Ten specific senarios are listed in my current manual, but I am expanding this to 14,15,16? It took 100's of repeated tests to verify all of them were consistent.

jim sokolovic

I think that I misunderstood your purpose, initially...

You are not trying to provide any Oxygen, flue temperature, or smoke readings that would correlate to a certain CO in your chart - that would be absurd.

You are trying to provide the likely improper mechanical conditions that can exist, based on all of the measured parameters - C0, Oxygen, flue temperature, and smoke. That would be of great value, although flue temperatures seem hard to generalize on.

Am I following you now? How will you offer this info - only through your classes? Thank you for once again bearing with me, Jim.

Jim Davis

I couldn't have said it better. Certain CO readings all all inclusive of certain problem, but all readings are necessary to make final evalutions, even one that was not yet been mentioned and that is draft. Obviously as new equipment is developed, some new interpretation will come into play such as more positive pressure combustion chambers. When we make up diagnostic sheets each one is relative to specifics types of equipment, such as furnaces, or boilers(water or steam), high efficiency 90%+ etc. Temperatures change on the sheets based on equipment function. Right now I am only finishing the standard furnace sheet. I offer the information to everyone at all times if they give me the readings they collect. The chart is not necessarily self-explanatory without the support infomation discussed in class. If you would like I will fax you a copy of a gas boiler diagnostic sheet that we use now and see if it makes sense. Trust me the oil is a lot more complicated in its variations.

jim sokolovic

Thank you, Jim...

I would like to see it, for sure!

Fax # is (516) 484-6594

Please put "Attention to Jim S." on the sheet.

Good luck in all of your endevours!

Mad Dog

You gotta take his class when it comes near ya

Robert. Mad Dog

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

Robert O'Connor_6

Yeah

I have to agree Mad Dog. Ubfortuneately I'll be out of town when he comes to Maine next month. Also I understand it's mostly geared toward gas. 100% of my accounts are oil.

Regards,

Robert

jim sokolovic

O.K. Jim, I have received...

the Gas Boiler Diagnostic Sheet. I can understand your goals better now, and I imagine the in-person training would clarify the details.

One thing that I don't see is the confirmation of correct input rate, other than the very last step - "Only after completing repairs, adjust fuel pressure to maximize boiler performance and record final test readings in the far right column." Isn't this one of the first things to do?

Also, I was looking at that combustion chart that Alan posted (see "CO/CO2" post) more closely. The line for CO2 is shown on both sides (fuel rich and excess air), but the Oxygen is shown only on one side (excess air). If there is always a set (inverse) relationship between CO2 and Oxygen, why wouldn't they have shown the Oxygen line to rise as the CO2 line falls?

I know you had some issues with this chart, and you did point out the failure to show this, plus you gave some real field examples of the occurrence, but do you have any reasoning on why they would have left it out?

Thank you for making me think, too!

Jim Davis

CO2 & O2 - Fuel Rate

I think the reason the curve is incomplete is because it was developed before we had the means to actually measure or know that we were on the fuel rich side, but then in most cases the fuel rich side starts on the excess air side on all fuels. It is my belief most of the chart was developed by formulas rather than actual measurements and there was no need to want to know what happened on the fuel rich side with oxygen or was it possible that when the curve was created it couldn't be measured?
As far as fuel adjustments are concerned the combustion numbers indicate initially if the fuel is low, high or correct. But before any adjustments should ever be made to fuel, all mechanical issues, all venting issues and all combustion air issues must be confirmed, corrected, controlled and verified.

jim sokolovic

It seems that most combustion analyzers...

made now use an Oxygen sensor to take the reading, which is then converted and displayed as CO2. We have older analyzers here that directly measure CO2, using infrared technology. I never heard Oxygen level discussed years ago-it was always CO2, so the age of the chart could be the reason.

I'm still befuddled as to why you don't recommend taking the actual input rate from the gas meter on equipment, unless meters are less accurate or available than I realize. You show a CO range of 0 to 10 ppm as being one indication of the equipment being under-fired - are you assuming that this type of equipment is so crappy, that a good reading cannot be achieved at a normal input rate?

Jim Davis

I am more concerned that the BTU of the fuel is inaccurate or our actual ability to convert it to usable BTU's. Actually 0-10ppm is only underfired when Oxygen is above 9%. Had 4 appliances last week that as the fuel was increased the CO dropped from 40-60ppm to less than 10ppm. But normally the CO is above 10ppm when running correctly more often than not.

jim sokolovic

Thank you, sir...

for all your replies, patience, and not throwing a combustion analyzer at me! (those old infrared ones are heavy, and have sharp corners) ;^0

Jim Davis

Only throw the analyzers in class!:)

eleft_4

Jim,

These were taken a minute apart on a very windy day (20 to 35).
This unit started out having a light off CO of over 200ppm & 1+ smoke several hours earlier.

My hat's off to the guys that can get the CO down with 0 smoke in an hour to hour and a half annual service.

al

eleft_4

Jim,

These were taken a minute apart on a very windy day (20 to 35).
This unit started out having a light off CO of over 200ppm & 1+ smoke several hours earlier.

My hat's off to the guys that can get the CO down with 0 smoke in an hour to hour and a half annual service.

al

Jim Davis

Here is what I recommend

Having worked on many Carlin burners this is what I would recommend to a contractor if I was on the job with them:
1.Replace nozzle with .85 60 Degree Solid Nozzle 2. Increase pump pressure to 130# initially 3. Install Star Kap on chimney to minimize wind affect and set barometirc for proper overfire draft. 4. If two pipe system, convert to one pipe 5. Checking CO only, adjust the position of the drawer assembly for lowest CO at Light/Run/Shutdown and also checks if new nozzle is good 6. Now check all readings-O2, Temp, Smoke and determine if air needs adjusting or pump pressure. Also check Delta T of Air if furnace for 75-85 degree maximum-minimum rise. If out of range correct air flow.