The speed of molecules and a machine that sorts them

[Vrbic]

Is there any device that can sort the particles of some medium according to the speed at which they move in the medium or something like that? As far as I know, there's a machine that can sort particles by charge through a magnetic field. Is there such a thing for speeds and charged / uncharged particles?

Sorry if I'm in the wrong section, I wasn't sure where exactly to ask.

Thank you for your answers, opinions.

 

[pinball1970]

Is there any device that can sort the particles of some medium according to the speed at which they move in the medium or something like that? As far as I know, there's a machine that can sort particles by charge through a magnetic field. Is there such a thing for speeds and charged / uncharged particles?

Sorry if I'm in the wrong section, I wasn't sure where exactly to ask.

Thank you for your answers, opinions.

Electrophoresis gel sorts proteins and bases by size, not sure about particles. Where have you searched?
https://en.wikipedia.org/wiki/Electrophoresis

 

[anorlunda]

Might you mean a cyclone separator?
http://www.asmemetsection.org/wp-content/uploads/2014/06/NYC-ASME_2013.pdf

The basic principle is pretty universal. If you force a stream of particles to bend around a curve, then the fastest or heaviest particles are moved more to the outside of the radius.

A mass spectrometer is similar, but it is designed to separate particles with different masses but similar velocities. If I understand your question, you have particles with the same mass but different velocities. If it is a gas, it is non-equilibrium.

 

[Baluncore]

The average kinetic energy of free molecules is proportional to the temperature. But there is a thermal distribution of the kinetic energy of individual molecules. Every time one molecule collides with another, the KE and velocity will change. Because the time between collisions is so short, given time, the individual molecules in a gas or liquid approach that average KE.

Since KE = ½⋅m⋅v² the velocity of a molecule will be proportional to 1/√mass. Gas and liquid chromatography techniques are spectrometers that race molecules against each other to sort molecules by their mass or molecular weight.

If you want to sort molecules by velocity, independent of mass or species, it will need to be done quickly with a shutter or door, before thermal equilibrium is reached, probably by Maxwell's Demon in a rarefied gas where collisions are unlikely.

 

[anorlunda]

@Vrbic

Now we have guesses ranging all the way from a cyclone dust separator to a chromatograph. We need context. What kind of particles are you trying to separate.

 

[DaveC426913]

Add 'Maxwell's Demon' to the guess list.

 

[Vrbic]

Might you mean a cyclone separator?
http://www.asmemetsection.org/wp-content/uploads/2014/06/NYC-ASME_2013.pdf

The basic principle is pretty universal. If you force a stream of particles to bend around a curve, then the fastest or heaviest particles are moved more to the outside of the radius.

A mass spectrometer is similar, but it is designed to separate particles with different masses but similar velocities. If I understand your question, you have particles with the same mass but different velocities. If it is a gas, it is non-equilibrium.

I understand. Thank you. It is exactly what I was thinking about.

 

[Vrbic]

Thank you all for the discussion.