small boiler build

[firefly]

gentlemen , firstly let me say i am totally new to the steam build area so please ignore what may sound like stupidity ,
i a wanting to build a boiler to run a " PM Research - Steam Engine No 8. V-Twin." engine .on a steam tank .

http://www.steamhobby.com/tractor_tank/

this sounds weird i know but it fits in with my area of use for it .i have limited space and need to fit everything into the chassis ,
my question is ,
i have two pieces of 3 .5 inch copper tube , for boiler making 6.5 inches long .
i am thinking of making a small vertical boiler with a straight through 28mm flue , and copper hedgehog spikes in the base heating area ,
i want to make the boiler 5 to 5.5 inches high on the main body , with a gas burner underneath ,
the straight through flue is so i can place a super-heater coil into the flue and hopefully get better output ?

or am i dreaming ?

i have made a horizontal boiler with cross pipes , but this was a failure and too long in the end to fit ,
is a stubby horizontal a option .?

and the pm research engine is my option as funds are limited and it seems to be a good engine , , as most auto-start RC control twins are out of my price range , and i do not have the machinery for making one

any thoughts gentlemen

 

[Blogwitch]

Keith,

Now we are out in the open, and addressing a few more of your problems than through emails, here are a few shoot you down bits that need to be considered.

1) Hedgehog spikes in the bottom plate won't work very well because the heat is going up the chimney almost straight away. You either have to put cross tubes in like on Sandy's plans that I sent to you, or wait until I can measure up my boiler to get you details of a vertical tube boiler.

2) Forget a superheater on this size of engine, it can cause more trouble than being helpful, in fact on the sort of engine you are considering, it can be grossly detrimental, as you will not be able to use a displacement lubricator.

3) Have you considered where the gas for the boiler is going to come from? Unless you are going to mount a commercial gas cylinder onto the chassis (they are rather large) you will need a rechargeable gas tank. Now these are not a thing to be played with, as for one thing, they have to be made with special considerations, like they have to be tested to 360 PSI and are built to drawing specifications. I have intimate knowledge of building rechargeable gas tanks, and later in the year, I will be building several. I am yet undecided whether I should show them on here purely because of the safety issues involved. Most people buy a commercial one, that should come with it's own pressure test certificate, but they are not cheap.

4) Insurance? Unless you are inside a concrete bunker operating it all by yourself, you will need at least third party, up to somewhere around $5,000,000, maybe a little more, cover for use in a public area. If someone else enters the bunker or wherever you are at the time, that is classed as a public place, and that includes your own home and grounds, so that insurance has to be in place before you start playing around. Authorities and lawyers take a dim view of people who hurt other people by their actions, and you could very easily be paying out for the rest of your life.

So, I have painted a very black picture of running on steam, but if you take things steadily, think through things very well, ensuring everything is just so and to the correct way of working safely, then it can be done.

Any other way is a definite no-no and you should drop the idea straight away.


John

 

[sunworksco]

Should I acquire insurance for my nuclear steam generation plant boiler? ;D

 

[steamboatmodel]

Keith,
Have you consider using commercial parts rather than building your own? [ame]http://www.youtube.com/watch?v=0jlrhw3fFyc[/ame]
http://www.youtube.com/watch?feature=fvwp&v=uXdOr1UNS4A&NR=1
Until you gain experience you should start with proven designs. If John has sent you some of Sandy's plans there is no better place to start. As John says Superheaters in that size are not effective, I do run a pass over/through the flames to dry the steam a bit. As for fuel you should stick with ether the disposable ones or go with a commercial one. As for insurance the best thing is to join a Club, as most not only provide insurance, but also inspection and advice.
Regards,
Gerald.

 

[steamboatmodel]

Keith,

Now we are out in the open, and addressing a few more of your problems than through emails, here are a few shoot you down bits that need to be considered.

1) Hedgehog spikes in the bottom plate won't work very well because the heat is going up the chimney almost straight away. You either have to put cross tubes in like on Sandy's plans that I sent to you, or wait until I can measure up my boiler to get you details of a vertical tube boiler.

2) Forget a superheater on this size of engine, it can cause more trouble than being helpful, in fact on the sort of engine you are considering, it can be grossly detrimental, as you will not be able to use a displacement lubricator.

3) Have you considered where the gas for the boiler is going to come from? Unless you are going to mount a commercial gas cylinder onto the chassis (they are rather large) you will need a rechargeable gas tank. Now these are not a thing to be played with, as for one thing, they have to be made with special considerations, like they have to be tested to 360 PSI and are built to drawing specifications. I have intimate knowledge of building rechargeable gas tanks, and later in the year, I will be building several. I am yet undecided whether I should show them on here purely because of the safety issues involved. Most people buy a commercial one, that should come with it's own pressure test certificate, but they are not cheap.

4) Insurance? Unless you are inside a concrete bunker operating it all by yourself, you will need at least third party, up to somewhere around $5,000,000, maybe a little more, cover for use in a public area. If someone else enters the bunker or wherever you are at the time, that is classed as a public place, and that includes your own home and grounds, so that insurance has to be in place before you start playing around. Authorities and lawyers take a dim view of people who hurt other people by their actions, and you could very easily be paying out for the rest of your life.

So, I have painted a very black picture of running on steam, but if you take things steadily, think through things very well, ensuring everything is just so and to the correct way of working safely, then it can be done.

Any other way is a definite no-no and you should drop the idea straight away.


John

John,
I would be very interested in seeing your designs for gas tanks.
Regards,
Gerald.

 

[Blogwitch]

Gerald,

I am just upgrading my computer with new Windows 7 software, when I have it all stable in a couple of days, I will send you some plans by email.

John

 

[steamboatmodel]

Thanks John.
I am still on XP Pro on my computers, figure I am going to have ether install a larger drive on this one or hopefully talk the wife into a newer one.
Regards,
Gerald.

 

[firefly]

thanks for the replies , and the rather black painting of the hobby is as you say black , but makes sense ,
i do not want to use a mamod type boiler ,
and i am now working on the drawings of sandy 3" boiler to the letter ,, as it fits well . and by far exceeds the pressures i intend to run with , when tested
as for the gas supply it was always intended to use a commercially made and tested rechargeable gas cylinder ,
so bearing in mind the multitude of conflicting advise on steam sites worldwide about materials , it can be hard to sort the good from bad
one interesting thing is the boiler bushes ,, many sites sell brass bushes ,, though when checked it appears these are not the best , so it the bronze route for me
have had 35 years in engineering fitting shops i am well aware of the dangers of doing things wrong , so slow and steady is the way

once again thanks for the comments

 

[rbott]

Re BLOGWITCH item 2; Why do you say he can't use a displacement lubricator with a super heater?
I would like to point out that we have been using super heaters with displacement lubricators for many years on steam locomotives, both before and after the super heater. The only requirement is that you must use special steam oil so as to not carbon up the system.
Robert

 

[Mechanicboy]

Re BLOGWITCH item 2; Why do you say he can't use a displacement lubricator with a super heater?
I would like to point out that we have been using super heaters with displacement lubricators for many years on steam locomotives, both before and after the super heater. The only requirement is that you must use special steam oil so as to not carbon up the system.
Robert

With dry steam generated by super heater, the displacement lubricator will not works well due too little/lack of condensate water from steam to raise oil up to steam pipe. But in the model steam boiler with super heater the steam is not so dry enough, also the displacement lubricator is still operative. Forget what BLOGWITCH wrote about can't use a displacement lubricator with a super heater when we are talking about model steam boiler/steam engine.

In the real steam engine/locomotive (not in model steam engine/locomotive)

Superheated steam was widely used in main line steam locomotives. Saturated steam has three main disadvantages in a steam engine: it contains small droplets of water which have to be periodically drained from the cylinders; being precisely at the boiling point of water for the boiler pressure in use, it inevitably condenses to some extent in the steam pipes and cylinders outside the boiler, causing a disproportionate loss of steam volume as it does so; and it places a heavy demand on the boiler because a large amount of water has to be evaporated per unit volume of steam.

Superheating the steam dries it effectively, raises its temperature to a point where condensation is much less likely and increases its volume significantly. Added together, these factors increase the power and economy of the locomotive. The main disadvantages are the added complexity and cost of the superheater tubing and the adverse effect that the "dry" steam has on lubrication of moving components such as the steam valves. Shunting locomotives did not generally use superheating.

 

[robcas631]

I have a question that is slightly off topic. Can I buy a boiler made by someone from HMEN?

 

[Tin Falcon]

I have a question that is slightly off topic. Can I buy a boiler made by someone from HMEN?

I guess that would be up to You a potential buyer and someone here wanting to build and sell one.

That said I see some potential problems.
1) we are here as a hobby. Not professional engineers.
2) as a buyer you are assuming the builder/ manufacturer is building the boiler in a safe and proven manner using safe materials and workmanship.
3) the seller is assuming you are competent adult and will operate the boiler in a safe manner. Not run the boiler dry etc.
4) there is thing called product liability insurance that companies involved in manufacturing need to have. This is a device that protects both the manufacturer and the consumer.

My recommendation is buy a new or used boiler from a established company like this one .
JENSEN STEAM ENGINE MFG. CO., INC.
700 Arlington Ave.
Jeannette, PA 15644 USA

These guys sell spare parts for many of there engines so you can buy just a boiler if you like or a boiler firebox combo.
Price list here.

http://www.jensensteamengines.com/parts-list/parts-list-print.htm
Name brand jensen , wilesco namod are all out there on the used market as well.

The alternative is build your own
get a tubal Cain book or the KN Harris model stationary and marine steam engines book.

Tin

 

[robcas631]

Tin,

This afternoon, I had a discussion with my son (Mech Engineering Major @ Stony Brook U. and overall smart arse) and he pointed out just a few problems that could go wrong. Fubar was mentioned quite a bit. When he got to big arse crater.....I was convinced.


So what I will do is contact the links you provided and choise wisely!

JENSEN STEAM ENGINE MFG. CO., INC.
700 Arlington Ave.
Jeannette, PA 15644 USA


Regards,
Rob