HP steam cannon

[Deli]

I'd rather have a fire I know is small and is gonna be out shortly than a large fire that I have to sit around and watch burn for 6 hours because my gun is sitting in it. Thermite is a bad choice; I was just throwing it out there that it works, and does have a few advantages over a log (although it has many disadvantages, which outwheigh it's pros)

[POLAND_SPUD]

OMG thermite what is wrong with you people...?

DYI use a water heater elements it should work

[D_Hall]

I'd rather have a fire I know is small and is gonna be out shortly than a large fire that I have to sit around and watch burn for 6 hours because my gun is sitting in it.

I guess water and it's application in the extinguishment of fire are beyond your comprehension?

Thermite is a bad choice; I was just throwing it out there that it works, and does have a few advantages over a log (although it has many disadvantages, which outwheigh it's pros)

No, it doesn't have advantages over a log. You threw it out there because it's a "gee whiz" solution and you thought it would sound cool. The realities of thermite are obviously beyond you or you'd have never thrown it out there to begin with.

[Ragnarok]

600 tons is feasible for a locomotive. The heaviest I can think of, although bearing in mind, I am hardly an expert on US locomotives - is the Big Boy locomotives, which did weigh around 600 tons.

But thinking further, it does sound a little improbable (although by no means am I implying you are lying) that a fireless locomotive "exploding" would throw a loco that large 30 yards. Perhaps the story has grown a little in the telling.

This blast was caused by the fireman forgetting to fill the water tank before lunch, the water level dropped below the top of the firebox and the fire weakened it to the point of failing: KA-BOOOM!!!

Also sounds a little odd, given that usually if something went wrong like that, the copper firebox would fail before the steel boiler walls.

...Actually, I'm surprised I know/remember all that. Mind you, I used to be something of a steam engine nut, so it's not completely unexpected.

Back to the Future III reference

I think I've only ever seen #3 the once - the TV networks over here only ever seem to play #2 for some reason.

@Deli: Thermite is the first thing that pops into my mind for the purpose.... after heated arguments, hot chilli peppers, hash browns, political waffle, and third degree burns.
All of which would be more practical solutions.

Thermite will melt just about any metal you can name, except things like tungsten. How exactly do you think you can safely contain that?
Now, normally I'm not a fan of Brainiac, but this video shows the potential for destruction:
[youtube][/youtube]
If it can melt through an engine block, it's not vaguely suitable here.

[rp181]

thermite is crazy, fire is unpredictable (somewhat), ide say water heater element is the way to go.

Am i right in saying that 3000 PSI in steam will push a projectile faster then 3000 PSI in air because of its mass?

[POLAND_SPUD]

hmmm I am not an expert but I suspect it has something to do with the fact that steam has higher speed of sound...

DYI I like the whole idea of steam gun - it would defienatelly be something new here... but I don't really understand why you need to be so big... ? I think it would be better to experiment with it on smaller scale which would cut costs and would be it safer

do you reall need 200 bar ? 50 bar would be quite powerful

[D_Hall]

Am i right in saying that 3000 PSI in steam will push a projectile faster then 3000 PSI in air because of its mass?

It'll do it for several reasons....

1) 3000 psi steam is hot. Air is not (not normally, anyway). That heat represents energy that can be harnessed.

2) 3000 psi steam is hot. Air is not (not normally, anyway). Hot molecules move faster than cold molecules. That means that the mass flow through any flow restrictions will be faster. In systems such as this, you can't transfer energy without transfering mass. Faster mass transfer means faster energy transfer.

3) Steam has a molecular weight of about 18. By comparison, air has a molecular weight of about 28. Once again, this means the mass flow through any flow restrictions will be faster....

[Sticky_Tape]

The myth busters made a steam cannon with a I think 8'' diamter barrel and it shot a cannon ball about 100 - 800 ft guestimated.

[D_Hall]

do you reall need 200 bar ? 50 bar would be quite powerful

Me thinks he likes the idea of using dry steam.

[swinging_dic_tater]

Well, I think this is a great idea. I grew up around a couple of Stanley Steamers and the owners would shoot potatoes with them every once in awhile.

Just a question. Are there water heater elements that go over 190°F? If not have you thought about using a kiln? My wife's small jewelry kiln goes to 1500°F. It's a Rio Grande somethingorother.

I guess you have probably seen this webpage

http://web.mit.edu/2.009/www/experiment ... annon.html

and this .gif

[DYI]

So far no one has answered my question about MIT's steam cannon, so I'll assume that no one has figured it out yet.

[SpudUke5]

For example, in New Orleans, an egg boils at 105 degrees Fahrenheit and in Denver, a egg boils at 85 degrees fahrenheit. This is because New Orleans is below the sea level so there is more atmospheric pressure so the needs to be more energy to get that water to boil to overcome the pressure (energy) acting against it. In Denver, the atmospheric pressure is less because it is above sea level and therefore needs less energy to boil to overcome the pressure (energy) acting against it.

But the water boiling in New Orleans is still going to have more energy because is it at a higher temperature.

This is so wrong. If this was really the case I, who lives at 9275' above sea level, would not be able to have eggs in the spring ,summer or fall unless they were hardboiled. Temperatures are routinely above 85F. Average hot water out of your tap(not the heater) is 105F. You can not boil an egg with just tap water. The core body temperature of a healthy, resting adult human being is 98.6F. You can not cook an egg just by holding it in Denver.

Common sense should have prevented you from typing that statement.

The rest of your statement has validity. I suggest you either go back to
class and pay attention or correct your temperature units.

Ahh forgive me. I was paying attention, but im just too used to Fahrenheit, because its what i commonly use, like the whole U.S.

I meant Celsius, just as the others obviously thought of.

this is a reference from my chemistry teacher, so go talk to her if you think im wrong.

he meant celcius otherwise it doen't make any sense

Even then it doesn't make sense. By definition water boils at 100 C at sea level (not 105).

It varies with pressure.

And no matter what it shows, it has absolutely no relevance whatsoever to the topic.

Does anyone know the speed of sound in 700 degree F steam?

Around 615 m/s (2020 fps), although I didn't have an exact ratio of specific heats for steam at that temperature, but it would seem to be around 1.29.

Unfortunately, I can't find my book of steam tables, or I'd give you a more accurate answer.

This was my relevance, although not clearly stated. Since your working with more temperature and pressure, its going to be harder to hit mach 1.

Ive done my research, and listening.

[Lentamentalisk]

Since your working with more temperature and pressure, its going to be harder to hit mach 1.

90% sure this is wrong...
Higher temperature means that the gas particals are moving around faster, so they will have a higher SoS, and also with increased pressure the SoS is higher. This means that, although reaching the local SoS in the cannon is still near impossible (as always,) reaching the normal atmospheric SoS will be a hell of a lot easier.

[SpudUke5]

Since your working with more temperature and pressure, its going to be harder to hit mach 1.

90% sure this is wrong...
Higher temperature means that the gas particals are moving around faster, so they will have a higher SoS, and also with increased pressure the SoS is higher. This means that, although reaching the local SoS in the cannon is still near impossible (as always,) reaching the normal atmospheric SoS will be a hell of a lot easier.

In the terms of the projectile, it is definitely going to reach mach 1 easily, but i was talking in terms of the steam.

Either way, this monstrosity of a cannon is going to be amazing.

[Ragnarok]

@DYI: I have some undeveloped theories about MIT's steam cannon, but right now, they're totally wild guesses which won't help man nor beast.

I might look further at it, but it's never really been in my interest to figure it out, as a large and powerful steel cannon that needs to be set in a fire to work is hardly my kind of thing (says the man* who will seldom build a launcher that can't be neatly shouldered like a rifle).

However, you might do well to do as much research as you can into Ioannis Sakas' steam cannon.

*No arguments about this one, regardless of how mentally mature I might appear on occasions...