Water Between Two Plates
Water Between Two Plates
(OP)
Hello,
I was wondering if anyone knew the equation to find the necessary clamping force to expel a saline solution out from between two parallel plates. I would like the most general form of the equation if possible, but will provide more details if necessary.
Thanks!
:)
Helen
I was wondering if anyone knew the equation to find the necessary clamping force to expel a saline solution out from between two parallel plates. I would like the most general form of the equation if possible, but will provide more details if necessary.
Thanks!
:)
Helen





RE: Water Between Two Plates
We are more connected to everyone in the world than we've ever been before, except the person sitting next to us. Lisa Gansky
RE: Water Between Two Plates
Thanks,
Helen
RE: Water Between Two Plates
We are more connected to everyone in the world than we've ever been before, except to the person sitting next to us. Lisa Gansky
RE: Water Between Two Plates
I agree with BigInch, and it will also depend on how clean/dry you wishes the plates, purpose and surroundings.
Better to think outside the box?
What is the connection/gapform to outside?
Possible to use a combination of somwhat higher temperature (drying/steaming) and some vacuunm to suck the water out as water and/or steam? By wrapping the plates in a plastic sack and set vacuum to this?
RE: Water Between Two Plates
RE: Water Between Two Plates
Make them a tiny model and bring it into their office. Common sense has very different meanings for an engineer, and everyone else. Seeing is believing ;)
RE: Water Between Two Plates
We are more connected to everyone in the world than we've ever been before, except to the person sitting next to us. Lisa Gansky
RE: Water Between Two Plates
We are more connected to everyone in the world than we've ever been before, except to the person sitting next to us. Lisa Gansky
RE: Water Between Two Plates
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RE: Water Between Two Plates
RE: Water Between Two Plates
RE: Water Between Two Plates
... Please define 'all'.
And if you press the plates together, and the plates are smooth enough to press out 'all' water, do you have any inlet to let air (fluid?) in afterwards, to counterwork the outer (atmospheric environment or other fluid) pressure making the plates sticking together after all air and fluid is removed between the plates.
...And counterwise: removing 'all' the fluid will at least require the force counteracting the pressure from surrounding (atmosphere/fluid) acting on the plates from outside, as long as there is an open connection the same force will work on the inside of the plates.
How much over this force you need to counteract the capillary force, is still the question.
Or am I mistaken in the logic?
RE: Water Between Two Plates
We are more connected to everyone in the world than we've ever been before, except to the person sitting next to us. Lisa Gansky
RE: Water Between Two Plates
The most perfectly flat and smooth surfaces you might encounter in daily engineering life are those of gage blocks (Jo blocks, Go blocks). Wring two (clean, dry) gage blocks together and they stick. There have been measurements made that show the gage blocks stick due to Van Der Waals forces, and the "stickiness" varies in strength relative to the inverse of the gap between the blocks (well made blocks can have tensile strength of the wrung joint exceeding that of the tool steel itself, i.e. the block will fail in the parent metal away from the wrung joint in tensile tests). Ok, blah blah - but now wet the blocks with oil or water (not my blocks, thank you) and try to wring them together. You will struggle to get them to stick if the surface is wet, no matter how hard you press or how well you wring them. The film of fluid just can't be removed that way, likely due to the same effect of Van Der Waal's forces, only acting in the opposite direction (the thin film wants to stay on the metal block surface, with tenacity increasing as the film gets thinner). The only way to get the film off the surface is to wipe it with an absorbent material...or by physically changing the liquid's state (drying water).
RE: Water Between Two Plates
btrueblood- That is very interesting. I have thought about gauge blocks in the sense of not being able to pull them apart (when clean and dry) and that the diameter of a tube is inversely related to the height of the fluid and thought they must have a relationship. You're thought (I'm not going to wet mine either!) experiment nicely illustrates the phenomenon, but I feel there must be a definable relationship between the surface tension, area, distance between the plates, etc. I'm currently looking into things like vacuum pumps (with fluid tight ceramic plates) and the lubrication pressure of journal bearings to try and get a grasp on similar relationships. In reality, I'll only need the force required to prevent fluid flow between two plates, not the force required to actually remove all the fluid.
RE: Water Between Two Plates
We are more connected to everyone in the world than we've ever been before, except to the person sitting next to us. Lisa Gansky
RE: Water Between Two Plates
http://opu
The relevant info is in table 1.
Thanks again,
Helen
RE: Water Between Two Plates
We are more connected to everyone in the world than we've ever been before, except to the person sitting next to us. Lisa Gansky