Olfelt

[ron parola]

My friend Bruce has a LARGE lathe so no problem as far as replacing coils..... good luck. Yes you can get in there to repair a weld but pretty impossible to replace a coil with out MAJOR surgery

[Akitene]

That's quite an impressive job, Ron. Very neatly arranged. I bet the thermal efficiency will be on the high side.

Any chance to get another pic of your boiler, taken from above? I'd like to have a look at the coils and the downcoming inner tubes.

[ron parola]

Pics before welded into drum, downcomers have to be assembled in two parts into coils BEFORE they can be installed into drum otherwise no way to install them !

[Akitene]

Thanks for the pics, Ron. Definitely an impressive and neatly arranged work.

[ron parola]

Next query; starting on the top end of the boiler, any thoughts as to amount of steam storage space above the tubes. In my case I have the center tube end about an inch above the tubes and a section of tube to be welded to that; just for a reservoir. Now in a Stanley you need a LOT, but a boat, not so much, so any thoughts as to % of storage vs generator space? thanks rp

[barts]

I would make sure you have several inches of vertical steam space; this will help keep water out of the engine. I'd just have the steam dome be a piece of 3" or 4" pipe sticking into the stack.

- Bart

[DetroiTug]

Ron,

Great work!

Boat boilers can have the carry over troubles too, especially when blowing whistles/sirens, sudden acceleration/ over filling feedwater etc. The Ofeldt is pretty good about not succumbing to carry over conditions. Although, some precaution needs to be taken to prevent it. One is as Bart mentions, extend the center drum height a sufficient distance. Another way is a combination internal deflector/steam dome as I did on mine. A third method is a deflector only, as my friend did on his (auto use). His deflector is simply a large flat washer type plate under the steam outlets with a 1" hole in the center, that works too. On mine (auto use)I went closer to the original Ofeldt patent, whereby the short steam dome extends down in to the center drum and past the exits of the generation tubes. Water/steam exits the generation tubes at high velocity under hard firing. The internal tube deflects everything down and only steam comes back up to the outlets if the water level is maintained. I've only experienced carry over once when I manually overfilled the boiler while driving.







The Ofeldt is capable of making steam very quickly and maintaining demand. Here is a video firing up my car. Keep in mind this is a very hot kerosene fire, but it will make steam from cold in about a minute from main burner ignition. I joked the other day,. that if I get this firing up any faster I'm going to start casting doubt on the electric starter



-Ron

[barts]

My Lune Valley style boiler (like an Olfelt w/ lots of small coiled tubes but each making only three turns before reentering the drum) has much more problem with the water level lifting when blowing the whistle, etc. This is likely due to the introduction of steam-laden lower density water in the bottom portion of the drum by the lower tubes. When I build another pressure vessel for Otter (the current one is now 20 years old), it will likely be an Olfelt.

- Bart

[TahoeSteam]

Silly old man falls asleep everywhere. I distinctly remember being at a friends birthday party when I was 5 and he was asleep on their couch with a teddy bear!

Ron,

I'm liking your work! any interest in making a second?

[ron parola]

Let's see if this works out first!! Am winding a superheater coil and have wound up an economiser coil, Waiting for some more sch 80 fittings. I'll probably leave the old boiler in untill after the B&W meet and will swap out during the winter. Hopefully will have the boiler done in another month or so ( Hey I've retired; no rushing!). Hydro next and will see IF it makes any steam, I'm hoping for 150 psi on the pilot light!.... well maybe not. cheers rp