steam turbine and generator

Edited By Brian Baker 1 on 20/01/2011 13:26:40

Edited By Katy Purvis on 01/06/2015 11:32:45

What Mr Paul Horth really wants is to make a small simple machine which uses the waste and surplus steam to generate enough electrical power to provide light.He is talking that he needs of some 1 to 5 watts.Since the machinery he wishes to use is very small, in fact they are so small that they have dropped off the ‘bottom of the tables’.What do I mean?Most ‘engineering and physical algorithms used to make calculations contain ‘approximations’.These are usually derived by ignoring terms whose value is very small.I found that the efficiencies of a small turbines is very very small, so the requirement for an output of 1 to 5 watts could require an input of some 100 to 1000 times the required output value.Think about the ILMEC efficiencies where the winners’ efficiencies are of the order of 1 to 2%

A workable small steam turbine generating a few milliwatts and powering small tungsten filament lights is fairly easy to build.Such a machine would be a rotor of the Stumpf type (with buckets end milled in to its periphery) or the DeLaval type used by Mr Jeggi which incorporates the magnets and bearings running on a stationary shaft

The rotors Mr Horth wants to use are larger than those I used in my experiments. His is a 1.5” diam rotor and mine were from 0.75” to 1.25” diam.It is quite fun using a monotube boiler heated by two large butane burners and fed by a largish motor driven gear pump and a twin cylinder piston hand pump.In our conversations and letters Professor Chaddock’s work was leading towards the development of very small gas turbines.The modern approach is used by the successful gas turbines is different.

I understand well Mr Bakers trials and tribulations.The blue and seized ball races, the nasty scream as gears failed, the destruction of the cases as a rotor disintegrates.

So long as Mr Horth keeps the output requirements small (milliwatts) it can be done without the need for to high speeds, huge volumes of steam.The best thing is to make a rotor and casings and ‘suck it and see’.If the steam pressures are low you should be OK.

Good Luck

Not sure if it's been mentioned earlier but have a look at Tubal Cain's "Building Simple Steam Engines No 2". There's a simple turbine device with the wheel "pressed" out of copper sheet. It might just give some food for thought.

Keith

The ‘Jeggli’ type DeLeval is not so difficult to make.Each blade is curved.The inner curve (on the inner edge of the blade) has a larger radius than the outer radius.I used to make two cutters by drilling a suitable bit of silver steel and then mill or file saw like teeth on the end to make a tiny hole saw.You set the thing up as shown in the attached crude drawing.As you will see most of the saw clears the metal blank

Edited By Terryd on 22/01/2011 16:19:02

Edited By Werner Jeggli on 22/01/2011 19:46:28

Edited By Werner Jeggli on 22/01/2011 19:47:46

Today the Feb. 2011 issue of EIM (dare to mention it here?) was in my letterbox. It contains the first of a picture story  (no plans) of a Mr. Sheldrake, who built a (seemingly very successful, although the details are not out yet) flash steam hydroplane wit a turbine. 

Pictures show  the turbine wheel  (kind of asymmetric Stumpf type), the housing and the gearing (5:1). A very interesting article, I eagerly await the sequels.

It seems that the record was 32 mph; possibly it is bettered now...

Greeting, Hansrudolf