Model Engine Maker

Supporting => Boilers => Topic started by: gary.a.ayres on September 08, 2019, 10:50:35 AM

Title: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres on September 08, 2019, 10:50:35 AM
Hi!

First, the disclaimer: this thread will develop very slowly. I have a serious habit of starting new projects and have a whole bunch of others on the go (some steam-related, some not), all of which are vying for my attention. So this project will develop in fits and starts on a possibly geological timescale, and these will be documented here when they occur.

For the burner, I have ordered a nice looking vintage brass blowlamp on ebay, and will post pictures of it when it arrives. The rest exists only in my head at this point.

As a beginner,I asked a few questions on George's (K.B.C.) excellent thread 'Flash Steam Engine and Steam Coil', and received helpful responses from George, MJM460, Admiral_dk (Per) and Old School. Hopefully the conversation continues here...

First of all, on the water feed to the boiler: I am not yet at the skill level where I'd want to integrate an engine-driven pump into the system, although I'm sure that would be the ideal. Instead, I'm thinking of a hand-pumped pressure vessel as it will (I think) be easier at this stage. A driven pump could always be a future upgrade. MJM460 has been very helpful with many ideas, including thoughts about a system with two pressure vessels. I'd welcome further thoughts on that (and perhaps the Benson and Rayman book which is on its way will also enlighten me), but meanwhile my tentative plan is to build something like this example from Edgar Westbury's book 'Flash Steam' (not meaning to breach any copyrights, and I encourage anyone interested to purchase this classic book from Tee Publishing):

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/838435.jpg)

It seems fairly simple, and I can already see my blowlamp in there   :)

Your thoughts will be welcome.

Old School mentioned a pressurized coke bottle fed system somewhere online. I wonder if it's this one from the highly inventive JohnnyQ90, to whom I subscribe on youtube:

http://www.youtube.com/watch?v=AWoJCzTqU0Y

The principle is similar to what I have in mind, though I'll probably want to use something blingier than a coke bottle...

Well, that's as far as it has got so far. Feel free to comment, question, advise...

Pictures of the blowlamp to follow (OK, it's just a blowlamp. But it's a nice one  ;))

Cheers!

gary
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: Jo on September 08, 2019, 10:57:44 AM
Interesting, I'll watch this develop  :thinking:

First, the disclaimer: this thread will develop very slowly. I have a serious habit of starting new projects and have a whole bunch of others on the go (some steam-related, some not), all of which are vying for my attention.

There are a few of us here with that affliction  ::)

Jo
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres on September 08, 2019, 11:01:03 AM
I'll bet!   :)

Thanks for your interest Jo.
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: MJM460 on September 08, 2019, 12:28:09 PM
Hi Gary, Iím glad you got on with starting the new thread while the ideas are fresh.

That Fig 37 is the general idea, but instead of letting the water in the accumulator be depleted, with consequent loss of air pressure, if you use your hand pump to keep replacing the water to maintain the level, by pumping water into that vessel, the air pressure will be maintained and you should be able to run as long as you want, or at least as long as you are willing to keep up the pumping.  The second vessel I was talking about is an open tank from which the pump takes the water, the fuel tank is a third if you like. 

I think you will be able to keep up the water pumping, just as you do with your vertical boiler.  It will depend on how much heat that blowlamp puts out, and how efficient your coils are at absorbing the heat.  Ultimately, I think you will want to include an engine driven pump, but no reason that cannot be at a later stage of the project.  Certainly two fierce blow lamps would need more water than I would want to pump for long.

Interesting little turbine in the video, certainly a curious novel item.  It shows the same startup technique as explained by Old school, that is, getting the tubes hot, then admitting the water.  Obviously I am overthinking the issue there.   

When the coils are hot, Old school started pumping with the engine driven pump by spinning the engine with that pull cord, the little turbine needs the stop valve to keep water in the bottle while the air pressure is applied.  However, if Westbury says the check valve is necessary, I would probably include one.  It is always easy to try without it by removing the ball.  The start up procedure would vary slightly but I think it can be made to work either way.  The vessel in the water circuit gives you time to draw breath on the pumping, and not usually provided on a system with an engine driven pump.

Also interesting that the micro plant uses pencil burners.  I have wondered it one of those would do for a steam plant, but the ones available here are way smaller in output than my little meths burners, so I donít think that even two of them would be enough, unless you are into making a very small engine.  And I am not sure that such an engine would drive a pump.  But I am happy to be proven wrong.

I suffer the same affliction as so many others, and despite having the book for many years, itís still only number four on my list.  And that is real ďdonít hold your breathĒ territory.  Others can easily get in the way.  You are tempting me to break my self imposed rule not to start another until I finish one of the three underway.  Still, rules are made to be broken.

Thank you for the pictures and that video.

MJM460

Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres on September 08, 2019, 03:14:52 PM
Ah... yes, now I get it.

Instead of pumping air into the pressure vessel, you'd be pumping in water with the air forming a 'cushion' of pressure inside the vessel.. Keeps up the pressure, and has the added benefit of maintaining the amount of water in the system. Nice!

Will certainly give that some serious thought. Thanks.

I think that heating the tubes till they're pretty hot before admitting water is more or less standard - it makes the steam really 'flash', I believe...

It's always tempting to start new projects. Joan Miro said 'I work like a gardener', which I took to mean that he would move around his studio between different paintings, doing bits here and there and watching it all grow. And it means never having to be bored! But then, there's always the danger of the avoidance of difficult or onerous tasks by flitting over to something else. I'm sure we all know that one too...  ;)

Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres on September 09, 2019, 10:10:58 PM
The blowtorch arrived. Monitor 134:

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/838581.jpg)

It's a beauty - small but heavy and solid. Oozes quality.

But will it work?

It's of the self-pressurizing type - no plunger. It says on the reservoir 'benzolene and petrol only'. There's a spirit cup to preheat the burner. Scary...  :Mad:

I suppose I'd better try it out at some point. Will report back here...

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/838582.jpg)

 :)

gary

Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres on September 11, 2019, 12:20:03 AM
Disassembled the blowtorch tonight. It looks to be in pretty good condition. I gave the parts a clean in kerosene and replaced one perished fibre washer with an o-ring. Overall it's a lovely bit of kit and as long as the wick - which I didn't remove - is in ok condition I can see no reason why it shouldn't work.

Also ordered a cheap plastic jerry can from Amazon so as soon as that arrives I'll go along to the garage, get some petrol, and try the torch out.
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: Alyn Foundry on September 11, 2019, 12:20:46 PM
Hi Gary.

That's a nice lamp, I've been a collector in the past but with more interest in lighting, Tilley etc.

It is indeed a spirit lamp and will run well on the unleaded fuel available today. For a clean start use Methylated spirit in the cup and only fill the tank to between 2/3 and 3/4 full.

Light the Meths and let it heat up until most has gone before gently opening the control valve whereupon the vaporised fuel should ignite and burn quite cleanly.

From experience and stories I'd suggest an outside area, clear of combustible items to test your lamp. Point it away from anything that can be caught up to six feet from it because if the fuel hasn't quite vapourised a burning stream of fuel could very quickly change the title of your thread....   :)

Cheers Graham.

Post script.

I've attached a picture of one of my rarest Tilley lamps, an IL33. ( Doughnut tank ) These were used to illuminate without casting a shadow. It was recommended by Tilley that 3 should be used to fully illuminate a Billiard table. They hold a large volume of Paraffin and were pressurised by the use of a bicycle pump.
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres on September 11, 2019, 02:30:23 PM
 
Quote
... a burning stream of fuel could very quickly change the title of your thread....   :) 

Yes indeed!   :Lol:

Thanks for your thoughts, Graham.

I had most of the bases that you mention covered apart from how much petrol to put in, so thanks for that.

However I do have a couple of other questions:

 Do I put the fuel in the safety valve/butterfly nut opening at the top, or does it go into the opening at the bottom (I suspect the latter but don't actually know)? Or is either ok?

Also, when I take the bottom cap off, the opening seems to be totally occluded by a fibrous material which I assume is the bottom of the wick. Is it normal for it to close off the hole like this? And will the petrol soak into it easily despite it being pretty dense?

Other than that, I think I'm fairly clear about it.

Cheers,

gary

 :ThumbsUp:
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: Alyn Foundry on September 11, 2019, 03:02:29 PM
Hi Gary.

Yes, you fill it from the top. I'm not really sure what the plug fitted underneath was for, never found a lamp that came with instructions. Possibly to drain water, who knows?

Now, before I forget. The main reason these lamps got removed from service virtually everywhere was the fact that many who'd used Paraffin lamps had the habit of turning them off by releasing the pressure at the filler. With a Petrol version this practice is disastrous!! It results in a " fireball " not good at all.

Be safe, cheers Graham.
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: Jasonb on September 11, 2019, 03:32:05 PM
Yes best to play outside, This is Windy from ME forum with his flash steam hydro testing before another record attempt.

Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres on September 11, 2019, 06:19:10 PM
@ Graham - ok, from the top it is. Am grateful that you told me not to loosen the filler to turn it off. That's probably exactly what I would have done, as I'm used to the kerosene equivalent!

@ Jason - I'm sure my other half will agree with you - outside it is, and far, far away from her.   :Mad:
I'm pretty sure I have that issue of MEW - will dig it out if I can find it and take a look.

Thanks Guys.

gary
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: steamboatmodel on September 12, 2019, 12:34:52 AM
Other then Naphtha camping equipment most of my burners have been modified Butane/Propane camping equipment. Even with them I now do all testing and running outside, this was mandated by my wife when she walked by my work bench while I was testing a new burned. I had been changing nozzle sizes in the burner and instead of getting the six inch flame I got a 36" flame.
Gerald.
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres on September 12, 2019, 12:51:45 AM
Yes... I have tested a couple of burners converted from stoves. In pursuit of the perfect flame...

It can become pretty much an obssession in its own right. But not for my nearest and dearest nor yours, by the sounds of it!

Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres on September 15, 2019, 12:51:54 AM
I have just ordered 25 feet of 3/16 22 gauge copper brake pipe.

If it's good enough for Synthpunk...

http://www.youtube.com/watch?v=AbHPvIuwMcE

...it's good enough for me.
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres 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.

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/839000.jpg)
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: MJM460 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 donít 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

Title: Re: Flash Steam Generator (slow burning thread...)
Post by: Steamer5 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!
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres 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.
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: Steamer5 on September 16, 2019, 10:12:09 AM
Hi Gary,
 No itís not mine......unfortunately!!!!

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

Cheers Kerrin
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres on September 16, 2019, 10:14:57 AM
Looks great!  :ThumbsUp:

All the Best,

gary
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres 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:

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/840206.jpg)

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.
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres 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:

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/841295.jpg)

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:

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/841297.jpg)

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

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/841296.jpg)
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: MJM460 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

Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres 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... ?

  ;)
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres on November 10, 2019, 11:08:49 PM
Very slick piece of CAD here:

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/843751.jpg)

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:

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/843750.jpg)

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

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/843749.jpg)

All good fun so far.

 :)
Title: Re: Flash Steam Generator (slow burning thread...)
Post by: gary.a.ayres 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:

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/848046.jpg)

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:

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/848045.jpg)

The chimney and flange were silver soldered together...

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/848044.jpg)

... and then cleaned up:

(https://www.model-engineer.co.uk/sites/7/images/member_albums/173350/848043.jpg)

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: