Author Topic: 4 stroke lawn mower converted to steam, fabricating boiler (Read 19919 times)

GoVertical · « **on:** August 18, 2013, 06:13:38 PM »

Hi, after two years of testing the VAWT I realized I live in a really low wind area. I learned a lot of great stuff about PMA's and the need for a MPPT circuit. Basically I am taking the low RPM VAWT PMA and applying it the steam project.

Converting the 4 stroke to a two stroke was accomplished by using JB weld to add two additional cam lobes 180 degrees out off phase from the ones that were already there.

Using 100 psi air the max RPM is 700 to 750. At 50 psi air the RPM's are over 500.

I have started the fabrication of a mono tube boiler.

So far I have fabricated the pump that will be used to replace the boiler water as the steam is driving the engine.

NOTE: JW these images that wont display is because the forum there posted on will not allow them to show. Its kinda like pictures posted to the PUB not allowed to be viewed on the open forum.

electrondady1 · « **Reply #1 on:** August 18, 2013, 07:39:24 PM »

those are interesting rpm figures.
isn't jb weld a type of glue or resin?
i can't see those lobes lasting long with real steam.

GoVertical · « **Reply #2 on:** August 18, 2013, 09:32:27 PM »

Hi, it is a two part, high temp, epoxy. This is just a first attempt to get some experience working with steam. If I can get it to work the plan is to run it until it breaks and then do a upgrade of the failed part.

I plan to use a small rocket stove for the fire box.

GoVertical · « **Reply #3 on:** August 19, 2013, 01:25:21 AM »

possible safety valve for review

project is for a small 1 to 2 hp system

JW · « **Reply #4 on:** August 19, 2013, 09:53:32 AM »

The air cooling fins must be removed since they will absorb heat and condense your steam. With your air running tests, you should notice them getting cool.

JW

Frank S · « **Reply #5 on:** August 19, 2013, 06:06:22 PM »

Rather than removing the fins I am thinking it might be better to create a much more denser thermal mass by filling them with a Thermoceramic Coating you could use something like Super ThermÂ®: Reflective Thermoceramic Insulation Coating which is actually a roof coating just apply it in the fin cavities in several layers until filled then continue until the engine block is a solid mass .
when I was in high school I built a brass steam engine the thermal loss was horrific I later made a tube to slip over the cylinder and filled it with ceramic powder about the consistency of talc you could lay your hand on the encapsulating tube and not get burned. The little engine ran much better as well

GoVertical · « **Reply #6 on:** August 19, 2013, 06:59:44 PM »

Hi, thanks for info. This is just a first time project and I am trying to keep it low cost. I can probably pack the fins with vermiculite and have a cover over that. I am mainly interested in finding out how large the boiler has to be to supply about 50psi of steam and how often I have to add water to the boiler.

I have seen some projects use spark plugs as a continuity switch to detect the high and low water levels and I should be able to fabricate a simple circuit to operate a 12 volt windshield wiper motor to operate the pump when the boiler needs water. Winter time operation is another problem area I would like to find out about.

dnix71 · « **Reply #7 on:** August 19, 2013, 09:50:06 PM »

No load rpm means nothing. You need some kind of dyno to load it down, then test rpm vs. psi.

An engine like that won't run long with steam. Running steam will pollute the oil. The crank will rust pronto and that will wipe the white metal crank bushing and the shaft seals. The valve seats are probably bronze alloy. They might survive.

Dry compressed air would work fine, but the efficiency of air motors is worthless.

Frank S · « **Reply #8 on:** August 19, 2013, 11:05:23 PM »

Have you considered a low temperature fluid like freon this would mean you would have to have a closed loop system but is would solve the lubrication contamination problem

http://www.youtube.com/watch?feature=player_detailpage&v=xpZxAZmrgeU

GoVertical · « **Reply #9 on:** August 20, 2013, 10:26:05 AM »

Hi, I am just starting with the basics. If the lawn mower conversion has problems there are other options. The video show a nice DIY engine.

GoVertical · « **Reply #10 on:** August 21, 2013, 11:19:03 AM »

Hi, does anyone know where I can find a suitable site tube to check the water level that can used with a flash boiler? Acrylic or glass??

JW · « **Reply #11 on:** August 21, 2013, 05:29:40 PM »

I've been debating the best way to reply to this post.

http://www.steamautomobile.com/ForuM/read.php?1,21517

There is an annual meet with the steam automobile club of America, its coming sep-19 to 21st 2013

I would love to attend but cannot because of work. Its a good lead follow it. I ended up spending about 250K on steam before I got to the point as to how I could construct the "perfect steam engine" one with no boiler, but it has one hell of a super heater...

The cost of attending that forum meet is $60 for all the events. But you can pick and choose and spend less. Its a really great way to enter the steam engine fraternity, learning basic safety also being a great reason.

JW

PS

Don't do this!!!!!!!
http://www.steamautomobile.com/ForuM/read.php?1,21637

The rest may get a kick out of the video

GoVertical · « **Reply #12 on:** August 22, 2013, 09:51:29 AM »

Hi, safety is a major concern. I have read that a monotube boiler will minimize danger.

The boiler tube will be inside the fire exhaust casing and if there is rupture the steam will exit the chimney.

JW · « **Reply #13 on:** August 22, 2013, 06:21:12 PM »

http://steamautomobile.com/ForuM/read.php?1,4606

I can see you are not using forced circulation, convective instead. I experimented with a convection circulation heat exchanger. It was fantastic demo shoot some steam in the air.

Rollys Derr boiler is the best we've see. For your type of convection flow working properly.

Although monotube steam generators are forced circulation and are made of coiled tubing they have no sight class. The closest to that is something called a "normalizer"

I have taken the time to visit with Tom Kimmel and asked him the questioned since "White" has a normalizer I asked now how does that work?

Tom replied a normalizer is a hole drilled at the very beginning of the superheater. If a maximum quantity of steam entered the end of the monotube would cause steam to be made when the monotube could not produce it. It was a hit with steam car's since if you flooded your monotube with cool water the small amount of water from the drilled hole would generate in the superheater and get the car moving, if the monotube flooded out, although this was uncommon since these steam machines used liquid fuel.

Jeremy Homes aka/JW

Frank S · « **Reply #14 on:** August 22, 2013, 09:15:17 PM »

From a safety standpoint rather than try to reinvent a boiler design why not go scraping and locate an old industrial steam cleaner used to clean equipment . they have a holding tank and autofill the boiler for recirculating steam add a condenser

GoVertical · « **Reply #15 on:** August 25, 2013, 07:01:52 PM »

hi, heavy duty monotube boiler fabrication. The video shows cold water feed at the top of the boiler. Does it matter top or bottom???

GoVertical · « **Reply #16 on:** August 26, 2013, 07:15:07 PM »

http://modernsteampower.wordpress.com/2012/08/08/homemade-wood-fired-lamont/

Article about monotube boiler rupture.

New concept drawing for boiler. Based on a LaMont boiler, I plan to try it without a circulating pump.

GoVertical · « **Reply #17 on:** August 27, 2013, 09:50:40 AM »

Hi, just a more complete concept drawing for the monotube boiler.

GoVertical · « **Reply #18 on:** August 30, 2013, 07:53:36 PM »

Hi, purchased all the needed part for the boiler.

GoVertical · « **Reply #19 on:** August 30, 2013, 09:31:15 PM »

correction, parts needed for the boiler

GoVertical · « **Reply #20 on:** August 31, 2013, 09:44:58 AM »

Coils, pre heater,economizer, and main

GoVertical · « **Reply #21 on:** August 31, 2013, 04:18:59 PM »

Hi, just some photos as I start fabrication.

GoVertical · « **Reply #22 on:** August 31, 2013, 07:00:43 PM »

Hi, I still have to fabricate the frame to hold it all together.

GoVertical · « **Reply #23 on:** September 01, 2013, 06:07:53 AM »

Photos of preheater and economizer coils

GoVertical · « **Reply #24 on:** September 01, 2013, 06:54:16 PM »

Hi, started frame fabrication.

GoVertical · « **Reply #25 on:** September 03, 2013, 08:00:32 PM »

http://www.youtube.com/watch?v=nhK9dsZVODM&feature=youtu.be

completed boiler fabrication, should be testing soon

GoVertical · « **Reply #26 on:** September 04, 2013, 06:36:13 PM »

Hi, I test fired the boiler. I would post a video but watching every threaded joint drip water is not that exciting.

I have to tighten every joint and make some alterations to the rocket stove. The pump works.

GoVertical · « **Reply #27 on:** September 06, 2013, 08:00:24 AM »

Hi, results from second boiler test. 30 psi max for a short period of time. I am changing the boiler design to resemble the attached image.

Bruce S · « **Reply #28 on:** September 06, 2013, 09:34:16 AM »

Which type of rocket stove are you using?
Or did you build one unique to this application? I've built a few and remain interested to different designs.
Your fabrication techniques remain at a high quality, which is needed when working with steam

.
Cheers;
Bruce S

GoVertical · « **Reply #29 on:** September 06, 2013, 10:14:02 AM »

Hi, I just trying to keep the rocket stove as small as possible. I am not sure what I will use for the final configuration. I did make the alterations to the main heating coil. This may work better. I still have to reassemble and do another small test. Safety is always a major concern. I will post results when available.

GoVertical · « **Reply #30 on:** September 06, 2013, 08:28:39 PM »

Hi, just a short video showing boiler leaks. Todays test revealed some problems. The fire is to small. The steam drum is to small. I have to find away to stop the leaks. The pump needs to be improve, when the boiler is at pressure the pump does not have enough pressure to add water to the boiler.

GoVertical · « **Reply #31 on:** September 07, 2013, 05:06:46 AM »

http://www.youtube.com/watch?v=_mGwPW4g5q0&feature=youtu.be

link to video

Bruce S · « **Reply #32 on:** September 07, 2013, 11:18:05 AM »

Might be the view and short vid, but, do you have any pipe-dope on those threads? I can't even see thread tape.
Rocket stove is loosing heat updraft from bottom being open too. All the stoves I've built needed to be sealed "except" where you wanted the heat to be at.
Cheers;
Bruce S

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Author Topic: 4 stroke lawn mower converted to steam, fabricating boiler (Read 19919 times)