How would steam pressure move a lid?

Discussion in 'Physics & Math' started by Bob-a-builder, Jun 14, 2019.

  1. Bob-a-builder Registered Senior Member

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    If you had a square pot on the stove and a square flat lid oversized by perhaps 1 inch all around its edges.

    The surfaces are all flat and the pressure can equal that of the lids weight.

    What would the lid do if the water boiled?

    The pressure gets extremely more powerful for this example.

    Would it
    a) Not move
    b) Move in one direction or another
    c) move randomly based upon geometry and pressures.
    d) Would the lid move straight along a linear left/right, forward/backward motion?
    e) would the lid just lift at one end and let the pressure escape even as the pressure gets higher an higher?
    f) Would the lid find maximum exaust by moving straight in any direction unitl more of pot is exposed and then stop moving as pressure subsides?
    g) Would the lid float and skew slightly until a corner is exposed
    h) none of the above? (explain please)

    If you are helping with this answer thank you and you can pick multiple answers above.
     
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  3. RainbowSingularity Valued Senior Member

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    7,447
    a 1 inch over hang on a 2 inch lid sitting on a 1 inch wide pot ?

    trying to hedge the questions to deliver a result to suit your own outcome is fairly poor science
    you are engaging in philosophy, not physical science

    you need to state your premise and then outline your ideological theory of philosophy

    you posted in the psychics and maths section, not the human sciences section on take a personality test via "my personal definitions of absolute non values of maths" as a "personality test".
     
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  5. spidergoat pubic diorama Valued Senior Member

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    It would oscillate up and down. It would build pressure until it moved up slightly, releasing the pressure, falling back down until it built up again. Just like any pot with a lid on it. Or it would just get stuck in the up position.
     
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  7. Bob-a-builder Registered Senior Member

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    No. The only reason a lid will stay on a stove pot is because of its design. Pot lids are always designed a little tongue in groove to prevent them from flying off at odd angles.

    I stated in first post that all the surfaces were flat. This means the pot "lid" is flat like a cutting board. No tongue in groove. No elevated sections of the lid.

    Just a flat piece of sheet metal on top of a meatloaf type pot. Have the lids overlap about 1" (or say 10% to satisfy rainbow dude who cannot surmise the average size of pots) all around to prevent tongue and groove and to allow exaggerated motions.

    It would rattle up and down at first but if the pressure became even greater it would find a balance above the rim of the pot and appear to hover/float on the pressure below. It would still rattle, but it would also move off the pot unless attached as they are. At least until the steam can evacuate via shortest route to low pressure.

    I suggest it would skew and angle. Perhaps exposing corners to the venting process due to shortest routes and the steam seeking low pressure.

    If I am incorrect nobody will claim. But saying the pot lid will remain stationary is certainly not correct. You yourself said it would bounce. Even bouncing would eventually vibrate off the pot.

    I don't make meatloaf so do not have such a container or I might consider filming this easy experiment.

    Anyone else?
     
    Last edited: Jun 15, 2019
  8. sideshowbob Sorry, wrong number. Valued Senior Member

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    7,057
    The pressure would not "become greater". It would equalize every time steam escaped.
     
  9. cluelusshusbund + Public Dilemma + Valued Senior Member

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    If the weight of the lid is not to grate an the seal between the lid an pot is not to strong an the extreme pressure dont occur quick enuff to blow the lid off... the steam woud escape by way of least resistance... an dependin on the factors i just mentioned... plus the condition of the surfaces of the lid an pot an how level the pot is... thers not enuff information to determine the lids movments.!!!
     
  10. Bob-a-builder Registered Senior Member

    Messages:
    123
    No. I had said "The pressure gets extremely more powerful for this example", but I understand your take if it was just a minimal level of pressure.

    The pressure would seek lower pressure and equal out as the pressure originally grew in intensity, but would then find more routes to low pressure as the gas (or steam pressure) grew in intensity. It would almost be entirely airborne (floating on the steam pressure) at a future point.

    It was the movement that would occur to the lid at this point which is the puzzle .

    I suggest that corners would likely be exposed first for the mass release of steam. I had suggested in a debate that the lid would skew and find a quicker route to escape in the corners due to such skewing.

    Thanks though.


    cluelusshusbund,

    Yes. Thanks also. We would assume the lid is flat and perfect in weight and level to the pot which is also level and as "perfect" as could be. Contained pressures would be "stormy" changing.

    We would assume the pressure is ever growing.

    Thanks for helping in this. I consider this resolved.
     
    Last edited: Jun 15, 2019
  11. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    19,252
    If the pan vents then the pressure cannot get "more powerful".
    As has been pointed out in nearly every response in this thread (and elsewhere): this would not happen.
    Which, again, has been explained to you would not happen.
    And, given your response, you consider it not only closed but, by completely ignoring everything that everyone (bar you) has said, you're still sticking with your (unsupported and incorrect) assertion.
    Tell me: why are you posting on a science forum?
     
  12. Bob-a-builder Registered Senior Member

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    123
    Wow! NEXT!

    I was not even going to dignify that with an answer, but maybe you believe yourself. Steady building pressure would not find satisfaction with just one route to lower pressure.

    Ditto. If this forum does not have anyone intelligent enough to handle a steam pressure science experiment I may go out and buy a meatloaf pan and film it for you. So you can wrap your brain around the effects of high pressure against a lid.


    Again,

    WOW! NEXT!
     
  13. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    19,252
    And the supporting data for this is... what?
    Just your claim?
     
  14. Bob-a-builder Registered Senior Member

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    I said, "Steady building steam (or any) pressure would not find satisfaction with just one route to lower pressure".

    and you reply.

    This is a physics section in a science forum. I should think someone here has a clue. Maybe not.

    So you're contending that the lid would always lift the exact same amount even when faced with increasing pressures within? and you wholeheartedly believe that that small lifting would never increase or seek larger routes to lower pressure?

    again,

    WOW!

    (Note: This from a guy who was a design Engineer for 40 years by claim)
     
  15. DaveC426913 Valued Senior Member

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    There are so many things wrong in just this one little sentence.
     
  16. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    The claim of "increasing pressures within" is your fantasy.
    (And, if you actually read what I - and others - have written, that's NOT what is being said).
    What IS being said is that, given a vent, the pressure will not increase. This is because each and every time its reaches a high enough value to lift any portion of the lid it will vent and reduce until it no longer lifts the lid. The lid will then drop and let the pressure build up again UNTIL it's sufficient to lift the lid and vent again, thus repeating the cycle.
    OVER 40 years: and it's verifiable.
     
  17. Bob-a-builder Registered Senior Member

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    I'm all ears DaveC426913.

    I suppose by saying "satisfaction" you think I mean the "rolling stones version"... Are there any smart people on this forum? Any?


    and Dywuddyr, If you boil water on your stove. When it starts to boil pressure will increase. The lid may lift and let out steam.

    40 years later (your claim of length of Engineer status), the water will boil so fast and fervently (look it up dave) that tiny lift it used to let steam escape won't be enough.

    I'm starting to feel like the teacher of romper room.
     
  18. DaveC426913 Valued Senior Member

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    18,935
    That's the least of that sentence's problems.

    I'll hazard that much of your engineering knowledge comes from Roadrunner cartoons.

    Stop. You really really don't know what you're talking about. Really.
     
  19. DaveC426913 Valued Senior Member

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    18,935
    This is not what you claimed earlier.
     
  20. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    19,252
    Correct. Except that the word "will" should replace your use of "may".
    Will it? Or will the lid lift slightly more so that the steam can vent? (And was that goal-post moving I spotted?)
    Given the grasp of logic and physics that you've shown so far (in any thread) I don't consider you capable of teaching anyone, pre-schoolers or otherwise.
     
  21. Bob-a-builder Registered Senior Member

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    123

    That's all you and dwydrry can say.. Nope nope nope. Even in the face of basic physics.

    Are you suggesting that a pot lid (any pot) when faced with internal pressures will let out a small wiff of steam and them be done.. repeatedly?
    NO. You are very unsmart (polite way of saying it).

    as the pressure grows. SOME STEAM will escape (seek lower pressure through vents created by steam powered lifting - not fly a helicopter over a prison wall)

    Then the pressure will grow faster. This means the venting will need to be greater. Eventually it would make the lid float off.

    ROMPER ROOM!

    However.. Your next trick is to make a claim and put words in my mouth. It's called Stawman.. so lets have it then.
     
  22. Bob-a-builder Registered Senior Member

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    SEE! I predicted your next trick would be Strawman and I had not seen your last post when I said that.

    I said that in my very first post. Obviously I cannot edit that as it was written yesterday.

    so your claim I had not said it earlier... debunked.. Strawman.

    Dwyddry,

    You are obviously "unsmart". I hope nobody reads your comments here or it could be embarrassing for you.

    This is child level physics you are failing at.
     
  23. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    19,252
    But you haven't posted any physics - just repeated, unsupported claims.
    Of course that's what will happen if the lid isn't constrained in any way.
    Which will reduce the pressure and let the lid fall back.
    According to you but not evidenced.
    And?
    Romper room - a playroom for very young children. Derived (so far as I can tell, from the TV program of the same name that was aimed at pre-schoolers).
    Can you actually quote where this has been done? Or are you simply making stuff up again?
     

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