looking for advice on a boiler project

[timo_gross]

Not a good idea to wait until no steam comes out. You could end up warping the metal and destroy it. Low water cut off is what you need.
HMEL

Hello,

... obviously a water glas should be made, it will eliminate the guessing.

Greetings Timo

 

[Steamchick]

As "lost" within the garbage I wrote above. This is Good for Timo's use at NWP of 3 bar = 45psi. The steam delivery depends on the heat source, and actual pressure and demand from the engine. AND it depends on having a continuous water supply, occasional supply, or NO supply. The bushes are fitted in the boiler end ready for the water gauge, water feed, etc. Just needs Timo to make them.
Cheers, K2

 

[Steamchick]

No not really collected any hard fact numbers, it is sufficient to drive a small thing like an Elmers Engines, or the Gerries Beam Engine.
Both engines run on compressed air well below 1 bar.
I would guess it also depends very much on the heat source and the insulation. (which are both not finalized yet)
I think this is not the best boiler for a "workhorse" engine, but good enough for "my toy" enginges they do not have to do work.
The running time is about 10 maybe 20 min and it stays well below 3 bar. (I get the safety valve only to open when I close the steam valve and wait a little)
Starting the heating with around 200 ml of Water. The total Volume as per CAD program is 290 ml.
I think the steam was fairly wet coming out of the boiler, some kind of overheating would be a good idea.

Maybe in the final setup I take the steam line once through the flame.


I hope that helps.

Greetings Timo

Hi Timo, you have got it right. Insulation can make a huge difference to steam delivery, as you minimise wastage (lost) heat. Also, the water quantity is almost immaterial, as in principle, for constant running of any engine, you want to keep the water within limits.
A dryer/ superheater can be a horseshoe loop thought the water tubes and can be very effective at making the engine run with less water exhausted in the wet steam.
Enjoy!
K2

 

[Steamchick]

Just for anyone interested in a bit of boiler design, I have done a study of the design by Michel Niggel, and the mods proposed by Timo Gros. (I may seem "sad" to some, but I enjoy it!). My basis is the ASME regulation limits, which may or may not have been appropriate for the original MN design, but I think should be applied to any changes of design. I think it is OK to ASME. (As expected).
I have based the design changes on the information from Timo as earlier in this thread.
(Moderator: if inappropriate for the original thread raised by Henry Banjo, this can be deleted. - K2).
Henry, I had a thought... the rectangular "boiler" you are studying may be the casing that contains the burning fuel, not the water/steam. That would make sense of the "26 thou thick ". The water/steam (I would expect) should be in tubes inside this "tank".
The boiler being made by Timo should easily power the engines you described, and is a good safe design. - Hope that helps?
Cheers!
K2

 

[timo_gross]

....
(I may seem "sad" to some, but I enjoy it!) Hope that helps?
Cheers!
K2....

Hello,
I think we can be grateful for this kind of constructive feedback. I hope it will help maybe someone searching for the first project.
I did not start with the water level glas, because I have other "higher" priority work respective fun stuff in progress.

Greetings Timo

 

[Bentwings]

A number of years ago our back road car cruise club visited an old garage out in the middle of nowhere the guy had the scariest boiler I’ve ever seen it was an old air tank that he filled with water to supply hot water to his pressure washer . He simply filled the air tank with water then set it on the barbecue grill and turned the flame on the fittings looked like the chickens welded them with chicken poop. No safety valve he just turned the heat down when it got hot enough. No pressure gage.

 

[timo_gross]

A number of years ago our back road car cruise club visited an old garage out in the middle of nowhere the guy had the scariest boiler I’ve ever seen it was an old air tank that he filled with water to supply hot water to his pressure washer . He simply filled the air tank with water then set it on the barbecue grill and turned the flame on the fittings looked like the chickens welded them with chicken poop. No safety valve he just turned the heat down when it got hot enough. No pressure gage.

The other day I cleaned a coffee cup. One of those, with a lid; Americans use while driving.
A little hot water to clean it. Close the cover, shake and... .boom, there goes the lid into the neighbours garden.
Danger never sleeps.

 

[PeterDRG]

The other day I cleaned a coffee cup. One of those, with a lid; Americans use while driving.
A little hot water to clean it. Close the cover, shake and... .boom, there goes the lid into the neighbours garden.
Danger never sleeps.

For cleaning coffee mugs, coffee pots or tea pots, Steradent or similar false teeth cleaning tablets takes a lot of beating. Diversey do a product industrially called Dual-Dip which is the same chemical.

 

[Steamchick]

Where do you buy Steradent nowadays? People don't even have dentures do they? Just implants, caps, etc.? - Will it de-scale the inside of a model boiler? The Supermarket have Dishwasher cleaner, kettle and Iron de-scaler, etc. but don't know if that is just an expensive way to buy stuff for de-scaling a boiler... My tub of Fernox central heating de-scaler is almost used-up.
But I always fancied some Dentists' tools for fettling small engine bits...
K2

 

[PeterDRG]

I got some last year, so it is still around. I don't think it is a descaler though. It removes stains. I've lots of dental probes from when Ash folded, 30 years ago.

 

[Bentwings]

I wish my coffee top came off easier I have to use a table knife under it to get it started . It’s a double walled thing so it can sit for several hours and still have hot coffee In it my in car cup lasts about 15 minutes at best . The top falls off way too easily

As for new boiler project the guys here can really help you . Forget about any kind of soldering Silicone braising works well if done right I don’t like copper as it doesn’t fatigue well when heated stainless steel has some coorosion issues higher alloys are better you also can run into electrolytic coorision so some kind of anodes are necessary I have some that ere used on my big boat that worked well in marine element. They are available from Amazon

I’d look at a 4340 alloy steel welded by very good TIG WELDER EVEN THIS IS subject CORROSION especially where fittings are installed . In any case a good hydraulic pressure test is necessary. There are several books and papers covering boiler design. Some times you may have to have a local inspector visit . I called sbout it but they told me as long as it was not fuel fired in a confined space my project was too small for them to come out. Steam is not a toy I got some pressure and temp tables on Amazon that are interesting and eye opening. Interesting in 5-6 years of mechanical engineering steam was hardly talked about other then research before you do steam. The amount of energy in steam is a stounding when compared to compressed air.

 

[Bentwings]

Few even good TIG welders can properly weld stainless steel. This stuff Duggar’s on the back side if you don’t back purge with argon it takes a double regulator to do this I was onevofvthecfew that had one they aren’t that expensive if you go with stainless request either certification and or weld coupon nobgoodvwelder would turn this down was my thought . These kinds of projects I though it was a very good reason to justify cost of project. Stainless is not that hard to weld but it’s easily over heated as it has poor heat transfer qualities most welders put way too much heat into it especially thin stuff . The sugar stuff wil cause eventually cracking usually sooner rather than later . Last thing you need in a boiler. I sold my brig welder as I really don’t see well enough to do high quality work any more

 

[Bentwings]

Once I can get restarted on my project I’ve made sketches for an ultimate test fixture to test to failure it will be done hydraulicly so there won’t be any explosions . The boiler will have end caps similar to RR boilers except not rivited. It will mostly be to check sealing I should bevablevtomopen the thing up for inspection , orcatbkeastcthatsctgevpkan It’s still one step away from the scrap pile however .