In a little over my head! Monotube boiler advice, please.

Hi there, folks! I'm new to this world of steam, and recognizing that you all are not, I was hoping for some advice.

I've been wanting to build a steam car, and have done some research regarding the project. I read that the boiler was the most difficult part, so I started there. The boiler I've made is a bit different in configuration that others I've seen, but identical in concept. I have gutted a turbocharger and converted it into a belt driven blower using a 12v dc motor (12" pulley on a 3,000rpm winch motor belt driving a 2" pulley for the turbo -- around 18,000 rpm just going off ratings). On the inlet of the blower I've installed a 2 barrel Motorcraft carburetor to handle fuel mixing. The outlet of the turbocharger blows into a 4.5' long 4" od 1/8 wall tube and the mixture is ignited with a buzz box and spark plug. I have about 85' of 1/4" stainless steel tubing inside the burner tube. The stainless tubing is bent into a plain coil. A triplex plunger pump feeds water into the tubing, going against the direction of the flame.

Jay Leno described his Doble steam generator as having enough power to heat a home, so I built my boiler with that in mind. The problem I've run into is that I'm developing an overwhelming amount of heat and steam (and VERY hot steam!); safety concerns have entered my mind.

What kinds of safety precautions do I need to be building into this? Check valves? release valves? General design safety in regards to plumbing the tubing?

I appreciate your input greatly, as does my wife.

Hi, Follow the Doble boiler posts. It`s about monotube boilers.
Don

Thank you, I will read through them.

Aristophanese-

You've jumped into a great "obsession", which you will gradually realize overtakes almost everything else in your life!

Your monotube sounds like it's going well-how much fuel are you burning and how much water are you putting thru your coil? Take some measurements-that'll tell you what modifications you need to get to where you want to be.

What's your overall plan-other than a steam car? What kinda engine are you going to use? What's your chassis going to look like? Those are things that will help decide what size steam generator you need.

Check out Jamison's efforts and ideas on this Forum-he's got quite a few things going on that might give you some ideas.

And show us photos of your work-especially your turbo/blower!!


Chuk

Hi Aristophanese,

Like Don, I would suggest "How I would Build My Boiler" thread.

I agree with Chuk...it's like an obsession

Kind regards,
Rick

Quote
Aristophanese
the mixture is ignited with a buzz box and spark plug.

Why does this remind me of a model T

Tim Nye developed a circuit board to trigger a Chevy LS-2 coil to ignite burners … the guys who stick big turbos on Japanese cars use the Chevy because the original coils don't have the oomph to work under high boost. Basically this will work like the old Ford buzz box but with a much, much hotter spark. They will be for sale through the SACA Storeroom.

Here are some pictures of the burner. The triplex pump and jackshaft from the blower motor that power it aren't attached in these. Right now it burns quite a lot of fuel. The silver can beside the carburetor is fuel, and it's only good for 30 seconds or so. I need to tune the carburetor a bit and remove the accelerator pump linkage from the throttle so that I can use it just for priming and not get flashes when changing the throttle position. My fuel pressure is probably a little high, so it's likely flooding at low throttle on top of everything else.

The "engine" I'm using is an m62 supercharger. I noticed that when it was on my car without the belt drive, engine vacuum would spin it. I ran compressed air through the outlet and it spun, then running steam through it, it spun very quickly. I have no idea how much power can actually be pulled from it, though. I've assumed that I'll need to spin the supercharger very quickly, then gear that down with pulleys to get enough torque out of it to move anything. Blower whine from steam was a pleasant and cool surprise.

As far as the car itself, I was honestly planning on building the car around the engine's capabilities, if I can build something that's actually up to the task.

Thank you for your questions and suggestions, everyone. There's clearly a lot I need to think about.

Edit: forgive me, I can't seem to get the pictures right side up and under 1mb.



Edited 1 time(s). Last edit at 03/12/2019 09:58AM by Aristophanese.

What I do is bring the picture into Paint Brush. You select the area and chose Rotate in the Home/Image. Then to resize, select Home/Resize and if the picture is 1.5 M, then type in 50 and enter. Note that both numbers will appear to make it a uniform reduction.

I always save the picture with "reduced" in the name.

Hope this helps,
Rick



Edited 1 time(s). Last edit at 03/12/2019 11:21AM by Rick.H.

Ari-

Man-you've got a trick setup with the turbo compressor! And you're running a S/Charger as an engine-that's a interesting way to go! Get some guages on your setup so you can keep track of the pressures/temps, etc..Remember to keep the supercharger gears well oiled. If you use this setup in your vehicle, you'll probably need to get a smaller motor on the blower-the winch motor will eat your battery pretty quick! But it's all good for getting the design down...

Keep going man-make it work!



Chuk

Thanks for the feedback! As far as killing the battery, my hope is to run the engine constantly at a low speed using a centrifugal clutch to let it idle. As long as it's turning, I should be able to fit an automotive alternator to it to keep the battery charged and blower running. A suggestion my brother had ( he's been doing electric vehicle conversions in classic cars, lately) was to use a DC PWM controller on the motor as my throttle, and eliminate the throttle blades from the carburetor completely. That would get me much finer control on the temperature and water pump speed.

As far as gauges go, what kind do you recommend? I found a 300 psi (I assume that's high enough) gauge on Ebay that says it's designed for steam, but what would I use for a temperature gauge?

Again, thank you.

McMaster.com has good professional bimetal dial thermometers which go up to, I believe, 1000F. Thermocouple setups are great for remote reading, but reportedly need calibration; best for folks with a strong background in electronics. Me & electronics have a love/hate relationship, so for remote readings during tests I have considered fitting bimetal thermometers with cheap/tiny webcams aimed at them, sending video of the gauge faces to a laptop, tablet, or smartphone via bluetooth. There is software that can split the screen to show video feed from numerous cameras simultaneously. It would be interesting to see a display screen with, say, 10 or more gauges displayed.

Remote pressure gauges of course can just be located on instrument panel/dashboard, connected via small metal tubes, with siphon loops for reading anything hot.

Several steam vets have told me to use pressure gauges good to 1.5x the normal operating pressure. I'm not sure whether this is still true, but at one time anyway pressure gauges were most accurate around the middle of their range.

I like your boiler test rig!

Peter Barrett and others have designed and tuned Doble-style/normalizer controls for monotube steam generators, to keep steam pressure and temperature within very narrow ranges, even under widely-varying load/speed road conditions. Dare I mention the somewhat different "White" steam car monotube control system? Ingenious and very effective...

Peter

Thank you for the suggestions and complement, Peter. I have a few things to build, some research to do, and some gauges to set up. I'll check in soon.

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