Steam turbine generator

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jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Steam turbine generator

Post by jscarmozza »

A few months ago I found an old edition of Live Steam magazine (Sept/Oct 1998), starting in it was a two part article on making a steam powered turbine generator written by Richard Chiapparelli, I'm curious to know if anyone has made or attempted to make a turbo-generator? In my spare time I've been playing around with different styles of impellers and the setups to machine them...all difficult and I'm not even sure they would work. The author of the referenced article silver soldered pressed blades to the turbine wheel, that technique didn't appeal to me beings that I'm a sloppy solderer. I'm also curious to know if anyone has tried to use a Tesla rather than an impulse turbine? I watched a few you-tube videos on micro-turbines and one guy built a nice running Tesla turbine using blanks cut from the bottom of a paint can for the turbine disks. It seems that the components of a Tesla turbine are simpler to machine, but I'm not sure if it will perform like an impulse, I understand that they tend to slip under load. I would like to hear what the live steam community has to say about this subject, thanks. John
KarlKobel
Posts: 161
Joined: Sun Mar 31, 2013 9:53 pm

Re: Steam turbine generator

Post by KarlKobel »

John,

I am nearly done with the alternator portion of the generator.
Instead of the rotor made of pieces and alnico magnets, I bought a 1/2 dia x 1/2 long, diametrically magnetized, rare earth magnet (K&J magnetics)

I bought castings from a supplier (I can't recall the name, now owned by Little Engines).
They are the same patterns used by the famous Mosley generator.

I'm kind of stuck with the rotor. I have a design, but it is going to require CNC.
Oh ya, it's impulse.
I do have a 3D model and drawings.
I am planning a LS&OR article.

Karl
www.karlkobel.com
jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Re: Steam turbine generator

Post by jscarmozza »

Karl you're way ahead of me, I'm still trying to determine if I have the skill level to make the various components. I kill a few hours a week and a lot of scrap seeing how to setup and how well a cut goes for various parts, the need for CNC concerns me. I can tell you this, there's a lot to it! I'd love to see an article on your build, particularly your generator, I'm really weak on the electrical theory. All of these things operate at very high RPMs, what kind of bearings are used, and how long do they last? I'm also curious as to where the exhaust steam goes, is it lost to the atmosphere, or is it recycled through a condenser? Thanks for your reply. John
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NP317
Posts: 4557
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Location: Northern Oregon, USA

Re: Steam turbine generator

Post by NP317 »

The exhaust steam is sent out the top pipe to atmosphere.
Look carefully at photos of steam locomotives in operation, and you usually can locate the steam exhaust from the turbo-generators, above the boiler.
They also produce a most ubiquitous whine. Etched into my brain for ever.
~RN
apm
Posts: 391
Joined: Sun Jan 05, 2003 12:21 am

Re: Steam turbine generator

Post by apm »

I have been thinking of building one for my 3-3/4" scale locomotive after I finish the engine, and the air compressor. I was thinking a little differently and wondering if it would be possible to find some sort of horrible freight air motor/tool that may be capable of running steam with minimal modifications.

To really operate efficiently a turbine requires very tight tip clearances which really don't scale too well. As a result I was thinking a vane type rotary engine would be much more doable in scale. Has anyone made one or found an air tool that would work for this purpose?
John Hasler
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Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: Steam turbine generator

Post by John Hasler »

It occurs to me that disks from old disk drives would make pretty good disks for a Tesla turbine. They are *extremely* flat and very well balanced so it would be easy to space them very closely (a requirement for an efficient Tesla turbine).
KarlKobel
Posts: 161
Joined: Sun Mar 31, 2013 9:53 pm

Re: Steam turbine generator

Post by KarlKobel »

RN - I agree, the exhaust just exits.

I pulled apart a old Mosley generator. The turbine configuration was puzzling to me. I'm not a turbine expert, but I believe the steam should flow, and expand, through the airfoil of the blade, not just 'blow' it around.
2012-05-05 17.03.45.jpg
Here is my current design for the turbine wheel.
turbine.jpg
The steam will enter from the side, pointed toward the cup, flow through the blade, swirl around the back side, and exit.
Comments welcome

For the electrical part, I still experimenting. I need at least 6 volts.
Electricity is generated by a magnetic field passing through a wire. The more wires that the field crosses, the more voltage.
Hence my experiment of how many turns I need.

APM,
Using a motor as generator will only work if the RPMs as kept low as a high RPM will destroy the brushes.
They are named generators, but really they are alternators (they product AC current).

Karl
Ken Schroeder
Posts: 156
Joined: Tue Aug 08, 2006 10:52 pm
Location: Gardnerville, NV

Re: Steam turbine generator

Post by Ken Schroeder »

Here is the generator I made for my 3 3/4" locomotive. The turbine has curved vanes with an outside band and a 15 degree steam nozzle impinging on the vanes. The generating unit is a 12 volt DC Pitman motor. I have 1 dummy generator left for sale but they can be made operational.

Ken Schroeder
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LIALLEGHENY
Posts: 363
Joined: Sat Jan 11, 2014 12:36 am
Location: Bohemia, NY

Re: Steam turbine generator

Post by LIALLEGHENY »

Ken,
Would you have or know where to get drawings to make an operational unit ? Looking to make one for 3" scale, with or without castings.

Nyle
jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Re: Steam turbine generator

Post by jscarmozza »

Karl and Ken, that's the wheel form that Richard Chiapparelli fabricated in the 1998 article I referred to. I tried to make that form but it didn't turn out very well. I made a shell type gash cutter (a hole saw with one tooth) to form the cups in the periphery veins, the cut was too wide and the wheel just didn't look right. I guess I should say that I'm trying to make a 1" scale unit, which raises the question; do the principles that govern the full scale prototypes still hold up when miniaturized? I also tried to make a wheel form similar to a pump impeller with arching side veins on the wheel. That didn't work out very well either, the setup was difficult and after cutting the the slots to form the top and bottom of the veins, hogging out the unwanted metal between the veins made a mess out of it. Again, this is why I was wondering if a Tesla turbine may be a better choice for a small scale unit, or as AMP suggested cannibalize an air tool for the wheel. Good discussion, interesting ideas, thanks. John
jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Re: Steam turbine generator

Post by jscarmozza »

Check out johnnyq90 on you tube. He makes some remarkable turbines!
Ken Schroeder
Posts: 156
Joined: Tue Aug 08, 2006 10:52 pm
Location: Gardnerville, NV

Re: Steam turbine generator

Post by Ken Schroeder »

I don't know of any drawings for the steam turbine. I was lucky enough to be able to borrow a full size one to copy for the patterns. The turbine wheel was made on a manual mill using a Volstro head. I copied a Delaval steam turbine design but only used 1 steam nozzle instead of the 4 that the Delaval had.

Ken
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