Author Topic: Flash Steam Generator (slow burning thread...)  (Read 9514 times)

Offline gary.a.ayres

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Re: Flash Steam Generator (slow burning thread...)
« Reply #15 on: September 15, 2019, 05:15:38 PM »
The blowlamp works  :)

I lit it outside but once I ascertained it was safe I brought it into the workshop out of the sun to photograph.

There was a very small amount of leakage around the filler cap / safety valve which caught light occasionally but it was easy to blow out. I'll see if I can fix this with an o-ring next time.

It took a while to warm up and get going and overall the flame wasn't quite as fierce as I expected, but I'm hopeful that for a fairly small flash boiler with the coil inside an insulated housing it will do the job. If not, I'll use something else as the heat source.


Offline MJM460

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Re: Flash Steam Generator (slow burning thread...)
« Reply #16 on: September 16, 2019, 01:21:47 AM »
Hi Gary, with the leak fixed, that should be quite good.  But very important to fix it with a petrol burner.  Check that the o-ring material is suitable for light hydrocarbon liquids, they will dissolve some materials.  Try and work out what the original material was.  A fibre washer might be more suitable.

You don’t want to complete with an Apollo rocket engine, well, not for your first experiments anyway.  That flame looks suitably moderate.

Once you have it all made, you can try with your silver soldering torches to get an idea of what works well.

MJM460

The more I learn, the more I find that I still have to learn!

Offline Steamer5

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Re: Flash Steam Generator (slow burning thread...)
« Reply #17 on: September 16, 2019, 01:38:27 AM »
Hi Gary,
Looks like a fun project! Once you get that boiler sorted you can move up to something a little bigger.........like this!
Get excited and make something!

Offline gary.a.ayres

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Re: Flash Steam Generator (slow burning thread...)
« Reply #18 on: September 16, 2019, 08:52:03 AM »
@ MJM460 - wise words and sound advice as usual. Thanks  :ThumbsUp: .

@ Steamer5 - wow, yes. Did you build that? I'll take a look at your topics later - I had a quick look just now - looks like you have some interesting stuff there.


There won't be much action on this thread over the next couple of weeks - I'm typing this right now from my camper van in a motorway service area in Darkest England.

Offline Steamer5

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Re: Flash Steam Generator (slow burning thread...)
« Reply #19 on: September 16, 2019, 10:12:09 AM »
Hi Gary,
 No it’s not mine......unfortunately!!!!

My Dad & I just get to help out, dad more than me! He’s just about finished an overhaul on the spare engine, the joys of being retired! It’s a fun day when we get to go for a ride!

Cheers Kerrin
Get excited and make something!

Offline gary.a.ayres

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Re: Flash Steam Generator (slow burning thread...)
« Reply #20 on: September 16, 2019, 10:14:57 AM »
Looks great!  :ThumbsUp:

All the Best,

gary

Offline gary.a.ayres

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Re: Flash Steam Generator (slow burning thread...)
« Reply #21 on: October 01, 2019, 10:35:21 PM »
Back from my travels. The copper tube has arrived, and in addition I have just ordered this:



My plan is to use this as the water feed in the initial, developmental/experimental stage just to get the feel of the boiler and how thirsty it is. Pressure vessels come later, I reckon. I also suspect that this pump could still have a role at that stage in feeding the pressure vessel.

I might change the reservoir to something different and find ways to funky it up a bit, but initially it's just about function. Who knows - maybe in due course I could use the existing reservoir to make the housing for the coil with...

Twenty-one quid. Not bad I reckon. My aim is to keep this project as low-cost as possible.

Offline gary.a.ayres

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Re: Flash Steam Generator (slow burning thread...)
« Reply #22 on: October 14, 2019, 10:50:48 PM »
The pump arrived. It works. The overall build quality is what you'd expect, but it pumps water ok and significantly more of it than a small brass model hand pump. It's also quite easy to vary the output with the amount of force on the lever.  I reckon it will do the job:



Taking it apart. I plan to find some kind of funky-looking container to replace the rectangular reservoir. I may make the existing reservoir into a housing for the coil. That yellow paint will probably go at some point. I guess the handle assembly could be changed for something a bit classier, but we'll see. I am thinking of plumbing it in copper instead of that rubber tube as the heat generated by the burner may not agree with the rubber. There's a plastic needle inside the check valve of the pump which I might have to copy in brass if I use copper pipe, as the conducted heat might melt the plastic needle. I read on Amazon that the thread in the picture below is non-standard, so if that's the case I'll have to get up to some jiggery-pokery or other to connect up the copper piping. And I love Marmite. On toast:



This box of tricks represents my flash steam story so far:


Offline MJM460

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Re: Flash Steam Generator (slow burning thread...)
« Reply #23 on: October 15, 2019, 06:50:47 AM »
Hi Gary, That pump should do the job, especially with your upgrade on the handle (and lever).  It will be interesting to see what that pressure gauge shows when the water hits the hot coil, and the engine takes off.

MJM460

The more I learn, the more I find that I still have to learn!

Offline gary.a.ayres

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Re: Flash Steam Generator (slow burning thread...)
« Reply #24 on: October 15, 2019, 09:12:36 AM »
Yes indeed, MJM.

For initial trials I'll connect the pump directly to the coil, but later I plan to build in a pressurized water tank system as we dicussed above.

And I assume it's Veggemite for you... ?

  ;)

Offline gary.a.ayres

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Re: Flash Steam Generator (slow burning thread...)
« Reply #25 on: November 10, 2019, 11:08:49 PM »
Very slick piece of CAD here:



It demonstrates the correct arrangement for the flow of water inside the coil, i.e. the cold water goes in at the end furthest from the blowlamp. It also shows that the length of the coil will be about 21 cm.

I then set about winding the coil. This was easy enough to do with the 3/16"  brake pipe without annealing it. As a former I used a bit of steel pipe of what I guess is more or less the right diameter, held in the pipe jaws of my vice. Way to go. I have never regretted buying this not very classy but all-singing, all-dancing, rotating, swivelling and pipe-holding bit of kit:



And finally, the coil wound, with the blowlamp shoved in the end of the pipe to give an idea of scale:



All good fun so far.

 :)

Offline gary.a.ayres

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Re: Flash Steam Generator (slow burning thread...)
« Reply #26 on: January 05, 2020, 10:19:40 PM »
A bit of progress. My plan is to make this boiler as cheaply as possible. As a rule I don't mind spending a bit of money when making stuff  (within reason) but cheap as chips is a guiding aesthetic in this case. Here are the parts that I have gathered up so far:



The pump, coil and lamp are discussed in earlier posts. The housing is a stainless steel bread bin (Brabantia - nothing but the best!) that I found in a skip. It may be a bit on the big side but given it's stainless I reckoned I could look for a long time and not find anything better. However, the space it offers could possibly allow me to add a few additional twists to the coil just ander the chimney to create a bit of superheating. Equally, I could always replace the present coil with a bigger one, given that the coil in these things is considered to be something of a consumable anyway. We shall see...


The wire mesh is a cheap stainless BBQ rack that I bought off Amazon - it arrived in that mangled state but luckily that's not an issue for this use, which is to wrap around the coil to separate it from the insulation. The insulation is ceramic fibre blanket left over from building a small furnace last year. I'm given to understand that it's nasty stuff - potentially carcinogenic - so a mask should be worn when handling it though it will be shielded inside the housing in use.

The chimney is a piece cut from a small gas cylinder from an oxy-mapp torch set, repurposed from another project after a change of direction. The mounting flange for it was machined from a piece of steel using the lathe, with the rotary table and dividing plate in the mill to make the bolt circle:



The chimney and flange were silver soldered together...



... and then cleaned up:



I love the way that the process of silver soldering transforms the look of the work from new and shiny to ancient and rusty then new and shiny again.   8)

Have a great 2020, all of you!

 :cheers:


 

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