Draft for a Smith Mills 44

knkreb

I have an old Smith 44 Mills steam boiler. (13 section) Thanks to Dan and this group, I have a great appreciation for it's beauty and design. She dates back to 1958 or so. It has an L J Wing draft inducer bolted to the back of it. The burner was replaced about 30 years ago with an Industrial Combustion MMG28. The belt drive motor is starting to have issues with it's start winding. It's single phase and the centrifugal switch hangs up and draws high amps then trips the breaker. I have reverse engineered the motor because someone chiseled off the nameplate. But looking at the whole set up, I think it's running too fast. There's massive suction (relative I know) when you open one of the front doors. There's a draft proving switch on the new burner, but there is nothing in the literature about where it should be set at. 

Anyone have any numbers I should expect to see?

EBEBRATT-Ed

You just need the fire box to be -.03ish when the burner is on high fire. Does it have a barometric damper there to help control the draft? It Should.

I used to have a Smith book with all that info got wet and moldy so I tossed it.

Not sure when they stopped making the 44s & 60s and changed to 450s & 650s could have been the early 60s

The more fire you put in the boiler the more draft you need the less fire the less draft you need.

I am sure the old motor is 1725 rpm so you probably only need to figure out the Horsepower. If you can get the motor running you could check the amps which would steer you towards the right horsepower and measure the voltage

knkreb

Thanks for your help!  So my hunch was right...too much draft. The inducer is spinning way too fast. My over fire draft was 0.75"wc. Not 0.075 no 18x higher than it should be. I found an old Cleveland Controls draft pressure switch still attached (and powered, just not in the control circuit). It had a hash mark with 0.04" on it. 

Ive ran the numbers and fan laws for new driven speed. Current fan speed is 2325 rpm. I need 710.  I'm thinking capacity and efficiency will majorly improve with proper settings and speed. 

I will keep you posted. 

retiredguy

If you want to get more information on that boiler and id fan you could call CS&E in Pittsburgh, Pa. at 412-821-8900 and ask for Tim Fugh in the service dept. They were one of the largest distributors of those boilers and fans. They may still have the original books on that boiler and fan. I am surprised that you didn't say that the draft controls are not working properly, since most boilers of that size when equipped with modulating or hi/lo fire burners were equipped with them. All the ones we sold had a draft control system installed and were controlled by Cleveland Controls. Give Tim a call.

vtfarmer

Those of us curious appreciators of antique heating equipment humbly request some pictures of this marvelous piece of steam heating machinery.

retiredguy

For those of you who are not familiar with the H B Smith Mills boilers, note that you can remove any section without disturbing any other section. This made it nice when on a rare occasion when a section would crack, that one section can be removed and replaced. Also, those boilers were a dry base, 3 pass, cast iron sectional boiler that could be fired with almost any kind of fuel including bituminous, soft, coal. Not a bad boiler, just heavy.

EBEBRATT-Ed

@retiredguy

Yes you could replace a #44 intermediate section with a 450 intermediate section. But if you had to change a back section it would fit but the smoke hood would not. Same thing for the front the 44 doors won't fit a 450 section.

I don't know if you can get replacement nipples anymore.

As far as I know Smith no longer makes the 350, 450 or 650 series boilers anymore. Hard to believe as I am in western, MA about 10 miles from the original Smith foundry.

Every building around here had Smith boilers back in the day, especially the schools

The only two boilers Smith sells know are the 19 and the 28 and Peerless also sells those same boilers with the Peerless name on them as ihe iron is made by Peerless.. The whole Smith thing is just about dead now. They make no resadintial boilers either

knkreb

vtfarmer said:

Those of us curious appreciators of antique heating equipment humbly request some pictures of this marvelous piece of steam heating machinery.

Here you go!

vtfarmer

Beautiful piece of machinery you have there. Nice vintage Square D disconnects on the wall, too.

EBEBRATT-Ed

I have crawled through those fire doors in the bottom picture many times in the past to repair/replace the combustion chambers.

Not so sure I could fit anymore LOL. The last time I went inside one I almost got stuck

Looks like your running gas there

retiredguy

Geeze @EBEBRATT-Ed, when we were younger both of us could easily crawl through those fire doors and play a game of poker in that firebox. Those H B Smith boilers were bullet proof. The worst item is the Wing Draft Inducer. Just wait till they have to replace the bearing assembly, you will learn some new "words". Do you remember the turbulators they made to be installed into the last pass. What a joke.

knkreb

Yes, gas it is... after much loving tender care, she burns and runs very reliably. The valve schedule is framed on the wall dated to Feb of 1960.

retiredguy

Geeze @EBEBRATT-Ed, when we were younger both of us could easily crawl through those fire doors and play a game of poker in that firebox. Those H B Smith boilers were bullet proof. The worst item is the Wing Draft Inducer. Just wait till they have to replace the bearing assembly, you will learn some new "words". Do you remember the turbulators they made to be installed into the last pass. What a joke.