Who remembers High School physics class?

[Big_Boy_4005]

QUOTE: Originally posted by blhanel

QUOTE: Originally posted by Big_Boy_4005

If the vent was closed during emptying, one would expect the damage happen more slowly and someone would intervene and open the vent before a total collapse.

The only problem with doing that is that, once the pressure starts dropping inside the tank, the differential would prevent anyone from being able to open the vent, unless it's a faucet-style vent.

Very true. It couldn't be something you had to pull on to open. You would need the mechanical advantage of a screw. I'm not sure what kind of valves tank cars have.

Also, if no air was allowed into the car during the emptying process, the material might even stop flowing, or perhaps come in uneven "glubs".

There are lots of examples of this principle in everyday life. Things like a vented gas can, drinking pop from a plastic bottle, and my favorite the new bottle of ketchup. All liquids flow better with air behind them.

[trainboyH16-44]

I did that a couple years back, Jr high not sr. Are you sure a UFO didn't land on it?
Matthew, highest marks in Physics 20

[Anonymous]

QUOTE: Originally posted by blhanel

QUOTE: Originally posted by Big_Boy_4005

If the vent was closed during emptying, one would expect the damage happen more slowly and someone would intervene and open the vent before a total collapse.

The only problem with doing that is that, once the pressure starts dropping inside the tank, the differential would prevent anyone from being able to open the vent, unless it's a faucet-style vent.

Balanced slide valves forever!

[richardy]

QUOTE: Originally posted by Modelcar

...Believe I remember of some kind of cleaning material used in a tank car..{it may have been the one pictured}, and the product used heat and after the cleaning the tank was somehow capped and when it cooled the atmosphere collapsed it....

The inside of the car had just been steam cleaned, all of the valves and vents were closed then everyone went home for the night.

[blhanel]

QUOTE: Originally posted by Big_Boy_4005

If the vent was closed during emptying, one would expect the damage happen more slowly and someone would intervene and open the vent before a total collapse.

The only problem with doing that is that, once the pressure starts dropping inside the tank, the differential would prevent anyone from being able to open the vent, unless it's a faucet-style vent.

[Train Guy 3]

cnw8835 THANK YOU!!![bow]

I'm getting extra credit for this one tomarrow!!!![8D]

[DrummingTrainfan]

I remember seeing that in science class a couple weeks ago when studying the Ideal Gas Law...

Someone did a major [#oops][oops]

[jeaton]

Now you understand why it is so hard to find top quality canned vacumn these days.

Jay

[Modelcar]

...Believe I remember of some kind of cleaning material used in a tank car..{it may have been the one pictured}, and the product used heat and after the cleaning the tank was somehow capped and when it cooled the atmosphere collapsed it....

[Big_Boy_4005]

QUOTE: Originally posted by chad thomas

No problem, just turn the pump around and blow it back up....right.....[8D]

Yes, but I'm afraid they just aren't quite the same after that.[;)]

A couple of years ago at the Minnesota State Fair, the U of M physics department had a show where they did this demo with a 55 gallon drum. With a small amount of water in the drum, they placed burners under it, and got it steaming pretty good. Then they capped it, and left it sit until later in the show.

The end result was much like the tank car, and happened very suddenly.

If the vent was closed during emptying, one would expect the damage happen more slowly and someone would intervene and open the vent before a total collapse.

[chad thomas]

No problem, just turn the pump around and blow it back up....right.....[8D]

[samfp1943]

Sombody forgot to open vent or dome lid when pumping car out.

[Modelcar]

...Just my thoughts on using the tank on the tank car as the frame structure....Understand the material is about 7/16" thick and a tube shape enclosed at the ends to support it's shape sounds like a very strong structure to me....

[bnsfkline]

can somebody say "oops"

[Anonymous]

Throw me another one! BBBUUURRRRPPP!!! [:P][:P][:P][:P][:P]

[Big_Boy_4005]

Like a giant beer can. I've seen one of those, though not quite so severe.

[ericsp]

QUOTE: Originally posted by trainjunky29

You know, having the tank car's tank be the frame of the car always sort of scared me. Is there any problem with having it be the frame?

I have heard of only a few incidences of tankcars being pulled apart. In general the construction of tank cars is not a problem.

[Anonymous]

You know, having the tank car's tank be the frame of the car always sort of scared me. Is there any problem with having it be the frame?

[Modelcar]

Looks like the pic's {Houston}, Ed had on here some months ago....No question, if {roughly}, equal pressure is removed from inside a vessel such as the tank car...the atmosphere will crush it....

[tree68]

Interesting - must have been pretty hot inside the car when they got done. Until I read it, I figured it was more like "hey George, did you open the vent?"

[Anonymous]

I guess the ideal gas law really does work! Take a look at this tank car. Does it remind you of a beer can?

http://www.delta.edu/slime/cancrush.html