Hello! Yes it was silicon tubing, which got replaced shortly after these videos were made. I have an amusing one of it exploding. It was used because i only started experimenting with it on thursday evening, and i wasnt expecting it to work first time!!! Apart from the roll of brakepipe, everything else used is from the scraps box, and so not chosen because of suitability, but simply because it was to hand...
I was told the silicon is good to 60 psi, but i very much doubt that now, or at least it should be derated for high temperatures. Anyways, the system is all copper pipe now, and is much happier.
Ive also built a new fully sealed enclosure along the lines of the one in the books, and it also works very well. Inlet and exhaust vents at the top, and 3 spirit burners.
I ran it today 7 times and it consistently and reliably and in the end, predictably;
Used 40 ml of fuel per burner per 15 minutes
Had steam up in 40 seconds
Had the engine spinning in under 2 mins 30,
And had achieved 'full military power' by 5 minutes in, which it maintained for on average, another seven minutes before the burners started to run out of fuel one by one, and it would drop down to cruising speed, and then finally 'dead duck' speed at the end..
It happily runs at 25psi. It can be made to race up to 50psi , but normally seems to self regulate back to about 25 or so.
The engine had a 'torque brake' on the flywheel to create a load.
At least one of the burners runs out of fuel by about 13.5 minutes after initial lighting of the fuel.the other two normally run out within the next two minutes.
The engine stalled under load at about 14 mins 30
It was normally dead with the torque brake removed by 16 minutes. Longest run was 20 minutes.
It no longer turns into a three foot pulsing fireball whilst running with three burners, the new enclosure contains it all within its shell. Which is very good, it was terrifying before!!
It used 1.25 ish litres of feedwater per run, the longer ones used a bit more
When everything is hot and running well (5 minutes since initial meths ignition) the pump varies from about 120 to 160 pumps (beats?) per minute (sorry im not an engineer, im a musician and instrument maker... i listen to what its sounding like to tell me how its running. You can hear all kind of harmonic resonances developing sometimes, due to the electric pump maintaining a constant tempo, which at some speeds resonates the natural harmonic frequency of the coil, and at some speeds of the engine, it can join in with tones of its own too, and create beat frequencies and (i presume) standing waves in the steam pipe that suddenly appearin and occasionally cause it to surge or race away....)
I mostly think of it as a 19 foot long, half wave resonator pipe. Same as a pipe organ. But with a steam engine at one end... ;c)
The pump is i think 3/8" bore and 1" stroke.
It generally runs between 20 and 50 psi at the outlet manifold. I have a safety valve set for 70 psi.
It has two bypass valves, one goes to the engine as a throttle, one over the side. I might try running it with a vacuum condenser and a chuff pot, so the 'waste' bypass valve may get used as an exhaust injector to draw a draught up the chimney. Probably join it into the system after the condenser and before the chuff pot.
Ill try and post some pics, once ive read the image posting rules...
Cheers!
Rich.
Ps, this flash steam stuff is really really good fun!
/edited twicedue to spelling and grammmar badnesses
Author
Topic: ET Westbury Flash Boiler (Read 10079 times)