Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: rfurzer on April 09, 2014, 03:06:35 am
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I have been reading about non-racing plants and have found this boiler - see attachment
Has anyone built one to this design?
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I have been reading about non-racing plants and have found this boiler - see attachment
Has anyone built one to this design?
Russ,
These pics in E.T.W,s book are concept designs and from all of my researches in M.E. mag on flashsteam I have never come across anybody who has actually built one nor one like the Flash generator on the previous page of his book.
It would be a very difficult build to make the coil in a figure of eight and the drums with all of the fins, this design is not a flashsteam generator but if built would produce very super heated steam.
If you are interested in flash steam generators and engines get a copy of EXPERIMENTAL FLASHSTEAM X BENSON & RAYMAN, lots of ideas for engines and coils.
Hope this helps
George.
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Thanks George- and good to hear from you. I do have the book.
I have seen and admired the boiler that you designed with "patternmaker" for his twin launch project. any chance of having a squiz at the drawings?
Also note with glee your thread on the st feed pump.
Russ
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I have been prototyping a version of this boiler. In the rayman/benson book reference is made to the boiler from a boat called Amazon from 1936. The design is very similar but without the finned water and steam drums. Mine is also similar, and without the finned drums, although it does have an economiser section and a superheater section. The coil is 19 feet of 3/16 kunifer brake-pipe.
Its all very new and experimental at the moment, i only started it last thursday. But anyways, heres a vid of it 5 minutes into a 19 minute run of a stuart BB10.
http://youtu.be/tsKS4Y4wItQ (http://youtu.be/tsKS4Y4wItQ)
And another, slightly larger engine-
http://youtu.be/iirAwVnu-9E (http://youtu.be/iirAwVnu-9E)
All in all i can really recommend this figure 8 coil pattern. Ive been using mine with 'soda can stove' spirit burners.
(http://i221.photobucket.com/albums/dd31/synthpunk606/Model%20sailing%20boats%20and%20steam%20boats/imagejpg1-36.jpg) (http://s221.photobucket.com/user/synthpunk606/media/Model%20sailing%20boats%20and%20steam%20boats/imagejpg1-36.jpg.html)
Quite an astonishing amount of bang for the buck. Which hasnt been very much bucks at all, maybe 20 pounds and some bits from the spares box. Mines going in a straight runner once its past the prototype stage..
All the best
Rich
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Hello.
Interesting indeed! Congratulations! :-))
Maybe an alternative to Flash Steam??? Safier at least! %)
I have a few question though!
1- What is the inlet pressure inside the machine? I see a silicone tube which does hold that much pressure : 4/5 b
2- What is the water pumping rate? (More or less)
3-What quantity of spirit is needed per min (+/-).
A bit more details on each components with a small comment is welcome.
Thanks for answering.
Regards
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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
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The 'business end' - pump manifold, with various one way valves, and the outlet manifold, with bypass valves, steam valve etc. like i say, tis is all made from cack from the spares box, it needs to be manned up with something better, but tbh in the 4 days since i built it, I've had a ton of fun and it hasn't exploded yet, so....(http://i221.photobucket.com/albums/dd31/synthpunk606/Model%20sailing%20boats%20and%20steam%20boats/imagejpg3-2.jpg) (http://s221.photobucket.com/user/synthpunk606/media/Model%20sailing%20boats%20and%20steam%20boats/imagejpg3-2.jpg.html)
One of the burners with the firebox door open--->
(http://i221.photobucket.com/albums/dd31/synthpunk606/Model%20sailing%20boats%20and%20steam%20boats/imagejpg2-2.jpg) (http://s221.photobucket.com/user/synthpunk606/media/Model%20sailing%20boats%20and%20steam%20boats/imagejpg2-2.jpg.html)
And closed--->
(http://i221.photobucket.com/albums/dd31/synthpunk606/Model%20sailing%20boats%20and%20steam%20boats/imagejpg1-37.jpg) (http://s221.photobucket.com/user/synthpunk606/media/Model%20sailing%20boats%20and%20steam%20boats/imagejpg1-37.jpg.html)
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This is 'Pressure Vessel I', which it magically fits in, as if it had been designed to, which it wasnt... But; yay!
(http://i221.photobucket.com/albums/dd31/synthpunk606/Model%20sailing%20boats%20and%20steam%20boats/imagejpg1-38.jpg) (http://s221.photobucket.com/user/synthpunk606/media/Model%20sailing%20boats%20and%20steam%20boats/imagejpg1-38.jpg.html)
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Wow! That's really interesting. Beautiful boat too.
What is a BB10? - never heard of it
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Thanks! Shes made from a set of IKEA blinds and a pine shelf i pulled out of a skip. The blinds were made from Birch, so shes double diagonal planked in birch on a spruce framework, with a pine keel and lower hull. ;) Finished in many, many coats of home mixed Garnet shellac varnish undercoat , lots of rubbing down and polishing and stuff, and then some yacht varnish topcoats. She was originally designed for a top heavy babcock boiler which has subsequently blown a watertube, so i need to play with ballast... She was designed to displace a large amount of water, and to counteract her previously top heavy tendencies theres 7 kilos of lead in the bilges.... So illl need to tweak that!
But im hoping shell work. This boiler weighs a fraction of the weight of the old one, so im prepared for some surprises!!
The stuart BB10 was a racing version of the 10V that was only available from stuart as a factory built unit and was made for a few years between 1936 and maybe 1940something? They are an enclosed, aluminium crankcase casting, with iron piston, cylinder head and valvegear and had a ballraced main bearing. Splash lubrication, looks like a cokebottle. Proper swoopy 1930s artdeco industrial design! Its probably my favourite single cylinder in my collection. They were designed for flash plants, but are quite rare. I certainly love mine!
Cheers! All the best,
Rich.
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Although we got a glimpse of the BB10 on the youtube clip, I wonder if you might indulge us with a photo for our viewing pleasure?
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Not my pic, but like this- http://gb.fotolibra.com/images/larger-thumbnails/354157-stuart-bb-engine.jpeg
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Thanks for the BB10 phot - pretty groovy.
I also found the website on the "soda can stove" - pretty neat. Does the fuel in the open well burn on its top surface as well as the vapourised fuel burning in the jets?
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http://www.stationroadsteam.co.uk/Stuart/BB.htm (http://www.stationroadsteam.co.uk/Stuart/BB.htm)
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Probably? But by the time the jets kick in, and you have three of them going, there is a LOT of flames so its hard to tell. Hot ones. Like a three foot fireball with a flywheel on it. But tbh, build one of the burners and find out! Only takes a couple minutes ;c)
Cheers!
Rich.
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Hello!
Thanks for all those datas.
Maybe , we can call it "Soft Flash Steam"?
I like it.
Cheers. ok2
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I don't know what to call it... Cruising power flash steam? Spirit fired once through steam generator? Maybe the Poor Mans Flash Steamer...
My vote is for the Victoria Flash Boiler. There's evidence that this pattern of coil was used by members of the historic Victoria Model Steamboat Club in London in the thirties. (The VMSC is the oldest model boat club in the world, dating back to 1904. We have a beautiful pond in Victoria Park in East London where I live, and we run straight runners, tethered hydro and the occasional rc boat on Sundays.) I built this one because I'm a member of the club and every normal boiler I own has some problem or other that's prevented me from getting a safety certificate and running a boat this season. So I've built this one to sidestep the problem- no pressure vessel, ergo; no need for safety certificate!
Also, the Victoria Flash Boiler sounds quite cool.. ;c)
I really can't recommend enough that more people take the plunge into flash steam- it's comparatively easy and cheap, and you don't need any special equipment, and you don't need a boiler cert. it can be as complicated or as simple as you want it to be, as long as you don't want tethered hydro type speeds! Otherwise it's more or less just get pipe, bend pipe, steam it!
Cheers!
Rich
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I've been progressing with my task of turning mine into a serious marine power unit. I have remodelled it, and made it about 35 mm shorter, and quite a lot lighter, and mounted it on an aluminium chassis along with all the other bits. I've added a condensor/ heat exchanger/ feed water preheater, an oil separator, and geared down the pump motor further. I must admit, I'm pretty pleased with how it's looking!
(http://i221.photobucket.com/albums/dd31/synthpunk606/Mobile%20Uploads/image-43.jpg) (http://s221.photobucket.com/user/synthpunk606/media/Mobile%20Uploads/image-43.jpg.html)
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heres a 4 minute vid of the latest test run. its now running on camping gaz canisters, and heating the coils via a Vango mini folding camping stove that cost about 20 £/euro.
http://youtu.be/uM7W1bPE1B0 (http://youtu.be/uM7W1bPE1B0)
<iframe width="560" height="315" src="//www.youtube.com/embed/uM7W1bPE1B0" frameborder="0" allowfullscreen></iframe>
as you can see, it runs pretty well now! the end of the video shows it clearly producing quite dry steam, in that once the burner is shut off with the bypass valve open and the pump still running, it takes some time before drops of water appear in the condensing steam.
hurrah!
i just need to sort out a water tank/ pond water filter and its going in the boat.
cheers! ;)
rich
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Very nice.
I have had a play with burners based on those stoves. Is all the gas burning in the casing. Or do you get flames out the stack ( eg if run in the dark)?
R
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I don't know! I haven't run it at dusk in this new configuration yet. When I tried it yesterday (before fitting the blower valve) the burner was having problems staying lit at full on. Today, with the blower valve installed, it struggled till the valve was turned on, and it roars away quite happily after that! I was really surprised by the difference it made!
I'm going to try and enlarge the air intake vents anyways, it will probably only help?
Hopefully I'll be able to increase the oxygen supply enough to enable two burners to be used. They flip flop between which one is alight and using all the air and which one is just wasting gas at the minute if you try running it with two.. :c/
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Also I've fitted an extra 4 feet of pipe in before the existing run and attached it to the cold water feed end as an extra economiser. The heat exchanger already does a great job at heating the feed water, so I guess it can only help. Seems to work at any rate! It goes in cold, comes out too hot to touch, and the exhaust steam goes in hot and comes out as mostly quite hot, but not uncomfortably hot water, and oil and a small amount of vapour.
I'm thinking of adding a steam trap to separate out the last of the water in the steam line before the engine. This is basically a pressure vessel version of a chuff pot/ oil separator isn't it? I was thinking of using a small pot boiler as a makeshift trap- wet steam in at one end, steam out of the other and all the water collects in the bottom. And space for yet another safety valve.... ;c)
Cheers!
Rich
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Hello!
Jolly spiffing demonstration! :-))
ps: do not laugh at my old fashion english! :}
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Thanks!
And don't worry, your English is perfectly smashing! :-)
I'm going to try it in an hour or two at dusk.
I've also got it going on two burners. You have to get one going, and get the blower on, and then bring on the second. After maybe 40 secs, you can turn them both up full. Gets to 25 psi easily, up to 35-45 by upping the pump speed and blowing into the inlet vents. More ventilation needed! It seems to use about 250 ml of feed water per 5 minutes, as a rough guide.
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It turns out this boiler, for a number of reasons that have only come to light today, don't work so good in the metre length boat I built it for. It's just too much power for a small hull .. (Hooray!!) so I'm going to have to build a bigger boat. So I thought, if I'm going to build a big boat, why not try a really big engine?
So, in the blue corner; weighing in at probably something like 90 cc capacity, with three cylinders of one inch bore and stroke, is the Enigma Engine: a valveless design with only 9 moving parts in total ( not including the two pumps, which aren't connected to anything) ; built sometime in the early 1900s by an unknown maker..
And in the red corner, my flash boiler. Here's the result-
http://youtu.be/PC3A9Umcvik
inexplicably just cruising along at 30 psi, (10 psi higher than previous maximum with the BB10 without changing anything!) then turning up the pump and the heat and pushing it to 40...
The higher load has resulted in higher pressure. Running this engine off compressed air on a large compressor, it empties the tank faster than the 1.5 hp motor can sustain it. I have never managed to run it on a normal boiler without it emptying it of steam. It's huge, it's hungry, and coincidentally it sounds like a spitfire. This engine was built for low speeds and high torque. It's a beast.
I think I've finally built my dream power plant for my favourite engine...
Hooray!!
Cheers!
Rich.
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Ooh! How super.
Is that a piston- operated (disc or poppet) inlet, uniflow exh arrangement? That would explain the higher pressure- benson and rayners book describe the compression ratio effect ( the residual exhaust gets compressed before the inlet opens. Short cut-off too.
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Its single acting, (semi?)uniflow (just one large exhaust port per cylinder) and valveless. No pistons, slides, poppets or disc valves, apart from the three main pistons which also act as their own valves. All just done with pipework. Almost unbeleivably simple. Ill buy you a drink if you can tell me how its done... ;c)
It has two built in pumps, one runs at shaft speed and one is geared down. Im planning on plumbing it into the feedwater system as well, to see what happens. Maybe ill get lucky and itll only need the electric pump for starting....
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The full list of moving parts :
1 crankshaft
3 pistons
3 crank rods
3 screws that act as compression release valves during the exhaust cycle. They are in the top of the pistons and are pressed up by little pips in the crank rods.
And thats it. No more moving parts, just pipes.
(http://i221.photobucket.com/albums/dd31/synthpunk606/Model%20sailing%20boats%20and%20steam%20boats/imagejpg1-3.jpg) (http://s221.photobucket.com/user/synthpunk606/media/Model%20sailing%20boats%20and%20steam%20boats/imagejpg1-3.jpg.html)
(http://i221.photobucket.com/albums/dd31/synthpunk606/Model%20sailing%20boats%20and%20steam%20boats/image-3.jpg) (http://s221.photobucket.com/user/synthpunk606/media/Model%20sailing%20boats%20and%20steam%20boats/image-3.jpg.html)
The crankshaft is only supported at the ends, its an inch thick. In fact, every major dimension of pretty much every component is either an inch, a quarter inch or an eigth. Its like an excercise in reductive engineering, its so simple its beautiful!
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Today i tried running the engine and boiler with two small gas canisters, half the size of the ones in the video. They cooled down far too fast, it generally wasnt a success.
However ive now mounted the two burners in the casing permanently, with a nice combustion space above them and around the coils. They burn best with the exhaust forcing a draft through the chimney. the flames are contained within the casing, unless the first burner doesnt light properly, in which case there are flames more or less everywhere but inside. I checked it after dark, it was quite exciting!. The flames generally burn blue unless theres no draft in which case they go more yellow.
I also experimented with using a pwm speed controller on the pump motor to see if i could use that to slow the motor right down and get rid of my external gearing down. It didn't work. Kept stalling when the load increased along with the pressure. When funds permit Im going to try it with a 100:1 ratio motor and gearbox combo and retire this one to backup duties. Till then its back to externally gearing it down..
Tomorrow im going to give the boiler a run with a true high speed (18,000 rpm) flash steam hydro engine, a twin cylinder single acting piston valve unit built in the seventies and quite compact. It may work, it may not. It was a pig to run on compressed air when i have tried it in the past but that probably had more to do with a rubbish compressor.
The three cylinder engine thats in the rig at the moment excels at lower speed stuff. Which is what the coil design of the boiler is for, after all. But it will be interesting to see how the boiler fairs with the racing engine. Until i put the water pump back to its geared down state, id guess not well at all!
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Hi Rich
I’m very impressed by your steam plant!!
I have a couple of questions:
Can you please say something about the brake that you have coupled to the BB10 in your first video? E.g. Is it a converted centrifugal water pump? If it’s a purpose built brake, how does it work?
Also, I am curious about the useful-looking aluminium strips to which to fix your equipment? Looks like they have slots and loads of tapped holes. Does this stuff have a name and do you know where to get it?
Cheers
Mike
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Hi mike! Cheers! That green thing is indeed a stuart turner centrifugal pump. The bb10 is part of an original pumping set, its quite rare. I had been planning on trying the centrifugal pump as a pump for the plant, but i havent got round to it yet!
My 'torque Brake' was simply a wooden clothespeg held by a clamp with the 'pointy ends' in between the flywheel and engine mounting, with another half a peg clamped in the jaws and tensioned by a selection of elastic bands to a hook some inches away. I adjusted it to give the same amount of pressure as my usual test, ie pressing my thumb quite hard into the flywheel until the engine almost stalls and then backing it off a bit.
My flatmate is a crazy slovakian ex army helicopter mechanic. We often socialise in my workshop, drinking shots and talking about machinery. He tested the big triple for me; it was his 41st birthday so hed been celebrating since breakfast, and was quite 'refreshed' by the time he wandered out to see the triple running for the first time. "Lets test the torque!!" He shouts, then grabs the spinning 96 tooth gear that it has instead of a flywheel... Hes a well built, strong guy. Apparently (and i quote)
" yes thats a good one. Nearly tore my hand off.... Drink?" :)
The aluminium mounting bars is extruded in a very complex cross section, you can slide strips of the tapped stuff into it for infinite adjustment. Its what large, super expensive recording consoles are made from. This stuff came from the old mixing desk from BBC radio norwich in the uk...
I cant remember what its called, but if you have access to an RS catalogue its in the enclosures section, but be warned- its extremely expensive! Its also used for making modular rack subassemblies, makers like BICC- Vero and Schaeffer do them, its a system commonly known as EuroRack. You can often find old modular sub rack assemblies in skips outside businesses that are having telecoms/server room upgrades if you are the kind of person who enjoys dumpster diving. Its where i get all my best stuff...
Cheers!
Rich
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Hi Rich
Thanks for the explanations and I see what you mean about the rail systems being pricey. I have just been looking and discovered that there's a whole world of these varioius profiles for racking systems out there. This made me think about using something like Al curtain track or lamp-mounting rails as a cheap alternative.
I certainly do look in skips but I doubt I'll be lucky enogh to find anything like the Z-rail and strips of threaded holes, but you never know.
Regards
Mike
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My latest findings with this coil:
I bought two small (100g) gas cylinders, and they are too small to run the big engine. It ticks over, just, but its a smaller amount of heat than just one burner connected to a larger tank. Im going to buy bigger tanks next time. Better surface area to volume ratio, and the propane and isobutane dont burn off so soon, just leaving boring butane.
I found the spec on the burners im using. The two burners, with isobutane/propane mix fuel, and large tanks, have a maximum combined output of 5000 watts. So my boiler runs at maximum as a 5kilowatt heater. Bloomin' eck! Thats nearly 7 horsepower of heat!
Id like to try making a more compact version of the coil, possibly in a folded configuration, with 12 feet of tube arranged in figure 8s going side to side and another 12 foot layer above it going front to back. Im a bit more experienced at how to bend coils now, i reckon i can do a much neater, more compact job than i did with this, my first coil.
Seeing as the current test article will run the big triple slowly or the stuart 10 very fast on one burner and a large tank, even with half the coil effectively out of the flames, i reckon its worth a try to see if i can get the whole length heated by one 2.5kW burner. It would also be able to arrange things so the water flows in at the top, and steam out the bottom(counterflow) which isnt really possible on the current single layer design.
If i can make a boiler with 24 feet of kunifer 3/16 pipe that fits into, say, a 4.5 inch diameter steel pot with burner at the bottom and exhaust at the top that would be cool.
Cause then i can make another one. With 1/4 stainless pipe, and its own 2.5 kw burner. And then connect them in series, so id have separate fine control over the main boiler(kunifer) and superheater (steel) sections, which seems like it would be super useful. I have some ss tubing that would be perfect.
And 40 odd feet of pipe would be an interesting experiment, although id need to man up the pumps, which brings us to--->
Ive also upped the pump motor to a mfa como 100:1 unit, its really good and powerful. No more stalling pumps! Im building a duplex pump arrangement with opposed rams on a common driving crank to try and get a more even flow, and also to double the flow rate possible with this motor/gearbox combination.
I am beginning to wear out components with the constant testing, taking apart, modifying, reassembly and re testing, i dont think this particular coil is going to ever get on the water. It will serve as a testbed, at any rate.
Ive also experimented with extra water pumps driven off the engines output shaft. Sucked lots of power out of the engine, and made it slow and surgey. Too much feedback in the system as well as extra load. Terrible idea. I may fit a magnet and tach to the flywheel, and use the resulting control signal (after some processing) to control a smaller 'acceleration pump' powered by another electric motor. Could also wire in a spinning balls speed governor with the lever arm connected to a control potentiometer controlling the same pump to try and control the surging. I have a suitable governor, reckon its worth a try!
Also i reattached the forced lubrication system to be big three cylinder engine. Theres a dashpot, a pump driven from the output shaft (geared down) and some check valves and a bypass valve involved. There is now over six feet of copper 5/32 pipe connecting everything together in the whole system..
Overall, its now resembling a 2 foot by 6 inch by 8 inch miniature oil refinery.
Or possibly a rocket motor.
Wahey!
Cheers
Rich