Nearly 900 degree stack temp! Carlin 100 CRD oil burner and original steel boiler.

MikeAmann

Mom's house, old conventional cast iron steel Burnham clone boiler with tank of water with tubes and baffles and firebox beneath.
I spent the last two days cleaning Mom's boiler burner and correcting other issues with the heating system. Mom has dementia so the house will most likely get sold sometime in the near future, so I just want to keep this thing running reliably until then.
The burner was so dirty that I had to take it all apart and scrub it clean in my parts washer. No service tech ever did a combustion analysis - I was the first. I figured that all the settings were not even in the ballpark, and that was verified after reading the manual. So I set it up according to this chart, got it running and began the combustion analysis.



Retention ring setting was left as it was.
Nozzle is .85x60A Delavan I didn't measure the pump pressure (yet).
Draft is -.033
Air band closed, air shutter set to 8 for zero smoke.
Stack 880 F
O2 8.8%
CO 39p
CO2 9%
Efc 67%
Xair 73%

So then I downsized the nozzle to a .65x60A Delavan
Air shutter set to 6 for zero smoke.
Stack 780 F
O2 10.7%
CO 42p
CO2 7.6%
Efc 66.7%
Xair 105.7%

I did not pull the baffles out, but I figure that there is virtually nothing left, so the flame is just going right through the tubes unrestricted. I went through this with my boiler. I can have laser-cut stainless steel baffles made for about $100. The boiler itself is in surprisingly good condition. The ceramic liner is solid. It blows my mind when I drain it that the water comes out crystal clear! Hot water baseboards and copper piping, 1 zone.
I believe that I can get this boiler up to 80% efficiency with just new baffles - slightly more restrictive to "baffle it down".

EBEBRATT-Ed

To find the rough nozzle size take the baseboard footage x 550 to get baseboard BTUs. Multiply x 1.20 for boiler efficiency and x 1.15 for piping and pickup to get the total input. Run the oil pump pressure at 120 and size the nozzle accordingly.

You may have to upsize nozzle if combustion suffers but I would start there. Your Co2# went down with the smaller nozzle. A firebrick in the flue pipe may save the cost of making baffles.

MikeAmann

Thanks @EBEBRATT-Ed , I will do that later tonight.

EdTheHeaterMan

880° stack on that boiler is to high. I bet those baffles are non existent. I would pull then and vacuum clean and brush the heat exchanger, vacuum out the base of the chimney. Then carefully remove any debris from the combustion chamber, and install new baffles, seal everything up and then pick a nozzle the will give you a stack temp below 550°.

Is the barometric draft control working properly? You want no more than -0.01 draft over the fire on a clean heat exchanger properly baffled.

They have 4 left. https://www.supplyhouse.com/Burnham-6113501-Turbulator-Baffle-6-Pass-x-18-1-2-Long-Steel-Tipped-RS-109-RS-112If you need more than 4 then Amazon has them toohttps://www.amazon.com/Turbulator-Baffle-Tipped-RS-109-RS-112/dp/B08VWT6HCC

MikeAmann

@EdTheHeaterMan

EdTheHeaterMan said:

880° stack on that boiler is to high. I bet those baffles are non existent. I would pull then and vacuum clean and brush the heat exchanger, vacuum out the base of the chimney. Then carefully remove any debris from the combustion chamber, and install new baffles, seal everything up and then pick a nozzle the will give you a stack temp below 550°.

Is the barometric draft control working properly? You want no more than -0.01 draft over the fire on a clean heat exchanger properly baffled.

They have 4 left. https://www.supplyhouse.com/Burnham-6113501-Turbulator-Baffle-6-Pass-x-18-1-2-Long-Steel-Tipped-RS-109-RS-112If you need more than 4 then Amazon has them toohttps://www.amazon.com/Turbulator-Baffle-Tipped-RS-109-RS-112/dp/B08VWT6HCC

That's exactly what I was thinking Ed.
I bet those baffles are non existent Me too.
vacuum out the base of the chimney Already done.
clean and brush the heat exchanger When the new baffles get installed.
carefully remove any debris from the combustion chamber I not going anywhere near the chamber that is as fragile as a potato chip. I learned my lesson on my boiler. But I will inspect it with a mirror. Unless there is a lot of crap in there, I plan to leave well enough alone.
Is the barometric draft control working properly? It is now. Weight was set to MAX, it's now close to MIN so that it just closes when not running.

26 and 57 each for baffles. I can have an entire set of baffles CNC laser cut from thicker stainless steel for about $100. All I have to do is bend the tabs out.
I am assuming that all of those Burnham clone boilers used the same baffle. I know that the tubes on my boiler measure 2-3/4" ID. I will start making the drawing tonight.
To refresh your memory, remember this?



EDIT: I'm glad that I checked. This boiler stands 44-1/2" tall.
18" for the firebox
24" for the tank/heat exchanger
leaving 2-1/2" at the top

It appears to have 8 tubes arranged like this:




Therefore this version uses the 24" baffles.
My boiler's original baffles had 4 "tongues, but I had them made with 5 tongues.
https://www.supplyhouse.com/Burnham-6113502-Turbulator-Baffle-4-Pass-x-24-Long-Steel-Tipped-RS-113

The 18.5" baffle shows 6 tongues.
How many do you think that I should design for?

Here is what I came up with:

Steamhead

@MikeAmann , what model Burnham?

MikeAmann

@EBEBRATT-Ed

EBEBRATT-Ed said:

To find the rough nozzle size take the baseboard footage x 550 to get baseboard BTUs. Multiply x 1.20 for boiler efficiency and x 1.15 for piping and pickup to get the total input. Run the oil pump pressure at 120 and size the nozzle accordingly.

You may have to upsize nozzle if combustion suffers but I would start there. Your Co2# went down with the smaller nozzle. A firebrick in the flue pipe may save the cost of making baffles.

68 feet of baseboard x 550 = 37400 BTUs
37400 x 1.2 x 1.15 = 51612 total input

Nice trick using the firebrick, but I want the heat to scrub the tubes along the baffles and transfer that heat to the water.

MikeAmann

@Steamhead

Steamhead said:

@MikeAmann , what model Burnham?

Burnham CLONE It has that Cloverleaf symbol with the H in the center.
It's actually Penn Brothers
Lancaster, PA
Model VO-5
Gross Output 95. M
Net Output 85. M
Max Oil Input .9 GPH

I believe it's the original to the house built in 1968.

HVACNUT

EBEBRATT-Ed said:

To find the rough nozzle size take the baseboard footage x 550 to get baseboard BTUs. Multiply x 1.20 for boiler efficiency and x 1.15 for piping and pickup to get the total input. Run the oil pump pressure at 120 and size the nozzle accordingly. 

Now to find a .38 GPH nozzle. 

What's the BTU input of the boiler? That's the firing rate it needs. Some manufacturers spec multiple firing rates for the same boiler. 

MikeAmann

@HVACNUT

HVACNUT said:

EBEBRATT-Ed said:

To find the rough nozzle size take the baseboard footage x 550 to get baseboard BTUs. Multiply x 1.20 for boiler efficiency and x 1.15 for piping and pickup to get the total input. Run the oil pump pressure at 120 and size the nozzle accordingly. 

Now to find a .38 GPH nozzle. 

What's the BTU input of the boiler? That's the firing rate it needs. Some manufacturers spec multiple firing rates for the same boiler. 

My camera is not good enough to get a clear picture of the nameplate.
Here is what is stamped on it. It has the cloverleaf symbol with the H in the center.

Penn Brothers
Lancaster, PA
Model VO-5
Gross Output 95. M
Net Output 85. M

Max Oil Input .9 GPH

Dad had the high-speed burner added probably sometime in the 90's. Original burner was 1725 rpm.
It looks like the Carlin 100 CRD oil burner now attached to it can fire as low as .5 GPH.



I will have to size the nozzle to get the correct stack temperature after the new baffles get installed.
That is as long as the other combustion numbers fall in line.

HVACNUT

Firing rate is .9 so a .75 nozzle @ 140 psi will put out .89 GPH.
Or you could go with a .85 @ 100 psi. With a 60° angle nozzle, make sure there's no impingement on the target wall. 

EBEBRATT-Ed

.9 input then i would fire it about .75gpr around 80% of rating

MikeAmann

Looking at the numbers calculated above, the boiler is oversized by nearly a factor of 2.
So why would I want to fire it at its Max Oil Input .9 GPH?
I want to downfire it for longer burn times and less short cycling.
I plan to start with the .65x60A nozzle that is installed right now and see if the pump will like running at 120 psi.
Of course, this all depends on what the combustion analysis numbers reveal.
Time to order some baffles.

EBEBRATT-Ed

No problem down firing as long as you get decent combustion #s and the stack temp has to be a minimum of 330 or so

MikeAmann

Some pics of the burner and combustion chamber.





The chamber is completely solid with only 1 crack line. It has not dropped and there are no hot spots along the sides. There is some crap in the bottom which I will very carefully try to suck out. I wanted to see where the retention ring was positioned in relation to the throttle ring. It looks like that is not set right either. How did this burner run reliably for the last 30 years? Notice that I did not say efficiently!

EBEBRATT-Ed

The retention ring setting is variable. Close the gap gives you more velocity and a short hard noisy fire. Opening the gap gives you a quieter longer less intense fire. It will work differently with different nozzles and boilers needs to be adjusted when esting. The book settings are not always right...they are a range

MikeAmann

@EBEBRATT-Ed
Thanks for the info Ed. I will set it at zero as a starting point and go from there.
That pic did not post, so here it is.


Good news. 2TwentyTwo Steel Designs, LLC will CNC laser cut stainless steel baffles for me.

HVACNUT

Its hard to tell from the pic but the insertion depth of the air tube should leave the end cone flush to .25 inches behind the face on the chamber. 

MikeAmann

@HVACNUT , you're right, from the pic it does look like the insertion depth is about an inch too deep.
Luckily, the burner has the universal flange shown in the paperwork that you posted above. Easy to correct.

MikeAmann

I had to disconnect the burner at the mounting flange to get a good measurement for the insertion depth. The crap in the bottom of the chamber was all the way up to the air tube. So I reached in to see if I could feel the floor of the combustion chamber - if there still was one. It is there. I proceeded to scoop out two containers worth. Unbelievably, the ceramic chamber is rock solid. I set the insertion depth to flush with the edge of the chamber (it was 5/8" too deep into the chamber), and the retention ring to zero also. Oh and baffles - what baffles? Nonexistent as expected. 6 are used instead of the 8 that I thought.
That's a 5 pound OXY Clean container!

Steamhead

Unfortunately, we see this way too often. That oil company was taking your Mom's money.

The light-colored particles in that mess are sulfur. Since the sulfur content of fuel oil has been drastically cut over the past decade, it shows how long it's been since that boiler has been properly serviced. I'd bet the baffles disappeared that long ago too.

This shows the inherent conflict of interest in having your fuel supplier do service. What motivation do they have to make the system run efficiently, since doing so would reduce their sales?

HVACNUT

I've often found missing baffles tucked between the block and the jacket.
Why vacuum when you can just makes the holes bigger?🤪

Do keep in mind that over the years, a steel dry base can't retain the heat as well as CI so a 500° stack temperature isn't unheard of.

MikeAmann

It could be just my imagination, but I swear the burner runs quieter now.

MikeAmann

Look what arrived today. 20 ga (.038") stainless steel. I can't wait to bend the tabs out.
I designed these to be a little more restrictive than what the originals were because this boiler originally came equipped with a low-speed 1725 rpm non-flame-retention burner. The Carlin 100CRD is 3450 rpm and flame-retention, so you must "baffle it down" to get acceptable combustion analysis numbers.

MikeAmann

I straightened out the plumbing by removing what was left over from the wood-burning stove being connected.
And I gave it a new expansion tank because I wasn't sure the original was still working.

MikeAmann

@SuperTech @WMno57 @HVACNUT @Steamhead @EBEBRATT-Ed @EdTheHeaterMan
It is almost 2:30 am where I am, and since my house is not going to have heat this winter, I took my custom-made SS baffles out of my boiler and I am going to install them in Mom's boiler tonight, err this morning. Her baffles are non-existent (or nearly so), which is the reason for the 880 degree stack temp.
Let's see how much of that heat I can keep down in the heat exchanger, instead of going straight up the chimney.

MikeAmann

What I found:

• Soot in the flue pipe.
  
• No insulation on top.
  
• No gasket at all for the breach cover.
  
• Baffles burnt away to virtually non-existent, as expected.
  
• But not even a drop of water leaking at the tankless coil gasket! The TC was abandoned decades ago.

The worst, the best, and my SS baffle.


One cool thing about these old tube and baffle boilers is the 2.75" ID tubes allow you to stick a light bulb down into the firebox to see if you did a good job of cleaning.




This is how I clean the tubes. And a shop-vac hose shoved down one of the tubes while blocking off the rest of the holes.




Well, it took 4 hours before I fired the boiler back up. Temp was 93 degrees.
So how did I do?

The draft (at breach) was unchanged. And SMOKE was still ZERO.


It only took about 5 or 6 minutes to get to the LO limit and stop the burner. I had to give a CFH to continue.




I changed the air shutter setting from 6 to 5. Still ZERO smoke. I am locking it here. I'm happy.
Here is the reading just before it hit the HI limit. And it only took 5 or 6 minutes to go from the LO limit (140) to the HI limit (170).



These numbers are almost exactly the same as the HWH with the Beckett AF burner. Both are using .65 GPH nozzles, except the I have the pump pressure set to 120 psi on the boiler.

Here are the CA numbers before the baffle change. Nothing else got touched.
So then I downsized the nozzle to a .65x60A Delavan
Air shutter set to 6 for zero smoke.
Stack 780 F
O2 10.7%
CO 42p
CO2 7.6%
Efc 66.7%
Xair 105.7%

RESULTS
The stack temp dropped from 780 to 450 degrees. That's a difference of 330 degrees that can now heat the water.
Extra air was cut in half.... 105.7 vs 52 percent.
The efficiency increased from 66.7% to 83%. I was hoping to get close to 80%. I call this a WIN!

EBEBRATT-Ed

Most defiantly a win. Any time you cut the stack temp efficiency goes up. I don't see anything wrong with steel boilers. Even on steam they held up pretty good

pedmec

Now send me your hours and materials so i can bill the customer please, lol

MikeAmann

@pedmec

pedmec said:

Now send me your hours and materials so i can bill the customer please, lol

Ha-ha. If I added up all the time that I put into this, I could have bought 3 new heating systems.
But those 3 will still not last as long as this 1 boiler will. It all adds up!

pedmec

Been there, done that, lol. chalk it up as a learning experience. Can you imagine if it was a customers house. ugh

SuperTech

Great job Mike! I would have aimed for a higher CO2% if possible to do while keeping it within 1% of a trace of smoke. But you shouldn't have to worry about it making soot with the combustion set that lean. I like your use of the drill for cleaning the tubes. Your mom is lucky to have a son who cares so much about taking care of her boiler. 

MikeAmann

Thank you @SuperTech

MikeAmann

The old oil pump shaft seal was slightly leaking, leaving a little bit of fuel oil in the air band area of the housing. I was going to just replace the seal, but the pump is the old design A2VA-7106 and the seal doesn't come out easily by just removing a snap ring. So the more I thought about it, I decided that I could use the new 7116B bio fuel compatible pump and crank the pressure up to 145 and drop the nozzle down to .60 GPM while keeping the same firing rate of .72 GPH. I made the change tonight and damn - I only had 5 minutes to get the combustion analysis readings before the boiler reached the LO limit. Good thing I was taking pictures. All settings were left the same as the last test.
Let's see what I got....




Slightly better. I'll take it.

STEVEusaPA

Those combustion numbers are ok, but not great. Excess air is high, I think you’re underfired and possibly draft too high.

MikeAmann

STEVEusaPA said:

Those combustion numbers are ok, but not great. Excess air is high, I think you’re underfired and possibly draft too high.

Thanks @STEVEusaPA. I appreciate your input.
The barometric damper is set to the lightest setting, so I can't get the draft any lower.
At the just barely a trace of smoke point, excess air is 40. So when I add my 1% safety margin, that's where I end up at 50.
And like nearly all of the old boilers of that era, it is 2X oversized, so I am trying to bring the firing rate down as much as I can for the longest burn times (minimize short-cycling) while still having a stack temperature high enough to prevent flue gas condensation.
I will sacrifice a little efficiency for clean burning throughout the heating season.

Considering where this started out - the burner housing was so dirty that I had to take it all apart and scrub it clean in my parts washer, virtually non-existent baffles, 880* F stack temperature, .85 GPH nozzle, all adjustments wrong, combustion chamber filled with debris all the way up to the bottom of the air tube, pump coupling fell apart, no insulation or breach cover gasket, Xair 73%, Efc 67%.

Now it only takes about 10 minutes to heat the boiler water from room temp to 170. That will happen when you are able to keep an extra 450 degrees down in the heat exchanger, instead of just going up the chimney, wasted. This couldn't have happened at a better time, because we paid 5.18/gal for oil.
I was hoping to hit 80% efficiency - 83% is a bonus! Not bad for a 54 yo boiler.

If the numbers really are too lean, then I can always put the .65 GPH nozzle back in, but I will continue run it at 145 psi. That will give me a FR of .77 GPH.

DJD775

@MikeAmann Is your draft at an acceptable level with the draft regulator at it's lowest position? On my boiler I had to add a washer under the weight to get the draft to an acceptable level. Been rock solid ever since.

MikeAmann

DJD775 said:

@MikeAmann Is your draft at an acceptable level with the draft regulator at it's lowest position? On my boiler I had to add a washer under the weight to get the draft to an acceptable level. Been rock solid ever since.

Yes, -0.028 at the lightest setting, and the flap opens more than halfway.
The clowns that "serviced" the boiler in the past had it set to the heaviest setting.
Between the now corrected settings and new parts and cleaning, I expect Mom's oil usage to be HALVED.

MikeAmann

I hate to bring this up again, but....
I noticed the nameplate on the Carlin burner

My cheap camera is not good for close-ups, but the writing says
0.50 - 0.75 70*H
Hollow Cone
Yet all of the literature says 60* Hollow.
I realize that this burner never was factory installed on this boiler.
My guess is that a service man might have used a narrower angle nozzle because he saw all the crap in the bottom of the combustion chamber.

Should I believe the burner nameplate (70*), or the literature (60*)?

STEVEusaPA

I forget what nozzle you have in there, too tired to scroll...lol. Keep in mind, uping the pump pressure may have affected the spray pattern, too.
I think you're ok where you are, but if you insist:
Run your burner with the existing nozzle, and set it up for a 1 smoke. Switch it to the recommended nozzle type (same firing rate, different pattern). Fire it up and don't touch any air/draft settings.
Take a smoke test. If it's cleaner than 1, that's the right nozzle. Adjust for true zero smoke and see what the analyzer results are now. If it's worse than 1, put the other nozzle back in, and re-adjust for true zero smoke. This is just a small sampling of a nozzle substitution test.

EBEBRATT-Ed

Like I said above. The MFG recommendations mean nothing if another nozzle works better.

Nozzle application test Charlie Burkhardts book "domestic and commercial oil burners" you can find old copies in used book stores.

I have had jobs where I used the MFG recommended nozzle and things didn't work out had the MFG rep come out and he used a different nozzle.

Think about it.

Draft, fuel, fuel temp, combustion air temp, oil pressure It,s different on every job.

Why would the same nozzle work? Just because they printed it on the burner. The nozzle they tell you to use is a "place to start' in my opinion.

If it works ....great. If it doesn't change it