The Steamboating Forum

I believe that on Wes's Dad's boat the turbo was running so slowly compared to automotive practice that all he does is grease the bearings.

I like the idea of the turbo. I just haven't found one that is small enough for my little 3 x 4 simple. Need to spend more time in wrecking yards.

I would probably have a simple interlock where before the fire door could open, an air shut off of some sort on the turbo would starve it. Simple linkage.

The largest unknown for me would be if I could silence the intake noise of the turbo.

Mike

That's a cutie but I think I can find one in a wrecking yard or a junk box for peanuts. It is, after all, an experiment!

Damping sounds is something I know little about. I once tried to improve on a stock Honda motorcycle muffler. I had a dyno and time and I failed. Everything I tried was either noisier of put out less power.

So while you are feeling all inventive, here's a problem that has been pestering me for years.

I would like to be able to force the draft on my VFT. Not all the time or heavily but enough so that if I need 20% more for an hour or so, I have it available.

Also, I am setting aside a regular steam blower for now as I don't care to start carrying a bunch more makeup water. I use enough now messing around with the whistle for good looking women!

What I'd really like is a way to put a fan in the stack or a fan outside the stack and duct it up there to work as an induced draft blower.

Hey Mike

How much taller would your stack have to be to get that extra boost 20%?

I am not sure how your stack is designed but I had given some thoughts to mine and had decided on using a double wall un-insulated stainless setup like that found on wood stove flues.

The stainless sections come in different lengths. They twist together and are secured with screws in each joint to keep them together. While being functional the setup would not be very pretty so I will wrap the outside of the sections in a single sheet of brass and place rivets on the seams to give it a more aesthetically appealing look overall. That way I get a functional as well as pretty stack.

The bottom double wall stainless piece would be secured to the top of the boiler frame. Say I use a 24-inch section secured via internal braces and welding (inside the space between the inner and outer walls of the double wall flue) so that the first piece is anchored permanently to the top of the boiler frame.

The upper pieces (however many it takes to make up the remainder of the stack height) would be secured to each other and an outer brass sleeve. The brass sleeve would be the entire height of the stack minus the lower inside piece. This assembly would then be slipped over the lower permanent piece and secured to the frame with some nice looking brass hardware. The upper section could then be easily removed for transport and storage, by removing said brass hardware and slipping the upper piece off and stowing it appropriately.

In your case you could fit a permanent piece of say 48 inches and build the rest of the stack the same way as described above. The advantage you would have at that point is an extra 38 or so inches of stack height simply by telescoping the upper section on the lower.

I am sure you are brilliant enough to figure out a way to make some interesting brass thingamajig to telescope your stack for extra boost when needed.

Cheers,
Scott

Hey Mike again...

I believe that on Wes's Dad's boat the turbo was running so slowly compared to automotive practice that all he does is grease the bearings.

I like the idea of the turbo. I just haven't found one that is small enough for my little 3 x 4 simple. Need to spend more time in wrecking yards.

I would probably have a simple interlock where before the fire door could open, an air shut off of some sort on the turbo would starve it. Simple linkage.

The largest unknown for me would be if I could silence the intake noise of the turbo.

Mike

Use a bigger turbo and turn it slow, that way you get more air and less noise. Use one half of the turbo (the compressor side) and run it off the steam engine shaft. You could vary the air intake to whatever degree you needed. Feed that air into the fire box or better yet up the stack via a ring in the lower part and make an air amplifier. You would not need steam in the stack as a blower and with a little creative brass magic you would have a supercharger you could engage and disengage very easy.

Cheers,
Scott

Hey Mike

Actually now that I think about it more I would not even bother with a turbo. The impeller guts out of a shop vac would move a lot of air even if not moving at full speed. And they have sealed bearings and are easier to find. I have five of them sitting on the racks here at work that were taken out of the Bosch shop vacs we use here. Since we are not buying any more of that type of vac I have a few that are now getting in my way. If ya want one or two to experiment with you are welcome to them. If ya cut off the armature winding's and made a flange to mount the shaft and the impeller housing you would have a two stage impeller head that could be driven via a toothed belt from the main engine that would move more air than you need.

I can see it now... That speed boat comes up beside you and asks if you wanna race! You smile and engage your supercharger, jack your stack up, throw in a shovel full of something that burns really hot, adjust your feed pump to high and say sure.

Cheers,
Scott

P.S. Hey! It could happen!

Speak up guys, I can't hear you over the whine of the blower!

Well actually my hearing at the higher end is not there. Not conclusive, but I got a huch the time spent listening to the high piched whine of the forced draft blowers is a factor.

The ship I was on drew the draft from the space around the uptakes. Air was provided to the boiler at ~100 deg F. The temp was fairly constant since the air demand tracked the stack temp which ran from 340F at low load to about 520F at full power.

Drawing the air this way also reduced the blower noise on deck to audible, but not offensive.

Yes Bart, chasing the back end of a carrier during launching, made our little ship had to grunt and strain for all it could do to keep up. AT those firing rates the system is working at the upper edge of it's design limits. I felt fear mixed with awe in the presence of such raw power.

More Hot Air!

Dave

All sorts of thoughts rolling in.

In no particular order:

I have a dial probe thermometer and I plan on seeing how much the stack gasses cool down from the bottom to the top. That will give me some idea of how much I might gain from an insulated stack. I'm about as tall now as I can go without looking really stupid!

Centrifugal blowers have a delivery v.s. r.p.m. curve that is wildly non-linear. They need a heck of a gear box if they are to be driven by the engine directly. I'll pass on that one.

I guess the r.p.m. thing is why I am looking for a smaller turbo. Compared to even a small I.C. engine, my steamer doesn't have much exhaust volume. I'll be surprised of I can get 10% of the rpm of that reached in the original application.

Which is why the unit won't need the exotic lubrication scheme that is usually used. Just a grease fitting should be enough.

I had no idea there were so many people stirred up by forcing the fire. My boat uses slid fuel. Would such a scheme affect a oil or propane fire as much?

Mike

Speak up guys, I can't hear you over the whine of the blower!

True if you turned them at design speed they are loud but Mike was talking about a 20% gain or so. You would not need the full (whatever) RPM... just enough to do the job.

Cheers,
Scott

Hey Mike

I had no idea there were so many people stirred up by forcing the fire. My boat uses slid fuel. Would such a scheme affect a oil or propane fire as much?

The only reason I have been doodling around with blowers the past couple weeks is because oil burners run hotter with forced air. Since you was talking about moving air for your needs I threw some ideas your way.

I believe that a drive for a blower for your application would not be as big or noisy as you may think. The drive I am experimenting with is a toothed gear and belt arrangement that is common in the cheep oil-less air compressors you see at home depot for 90 bucks. We go through the damn things here at work like old rags. Anyway it was just a thought.

Cheers.
Scott