Will dry steam pull more vacuum than wet steam?

Question

Fill 2 like containers with the steams and condense. Wouldn't the dry steam pull more vacuum? (also using less water?) How much vacuum? Steam pressures can go into thousands. Can vacuum go into negative 1000's?

Answer 1

Vacuum is the abscense of atmospheric pressure. So the most pressure dference you can have between a vacuum and room air is 14.7 psi or 1 atmosphere.

Although you are correct in realizing a greater seperation between steam molecules of dry(superheated) steam vs wet(saturated) steam having the potential to create a stronger vacuum.

However as pressure is removed from water the boiling temperature drops. As you approach high vacuum of 29InofHg you will find that water will boil at room temperatures.

So you will generate a stronger vacuum wih dry steam as it condenses into water. But becasue that same water is now under a vacuum it is possible to halt further condensation and vacuum formation because of the room temps adding heat which causes the water to boil (at a much lower temp) breaking further vacuum production.


So wet or dry steam will produce the same vacuum if there is any condensate in the vacuum chamber.

Answer 2

Dry steam is hotter and the heat makes for a bigger gap between the molecules therefore once cooled there will be more vaccuum

Answer 3

dry team does the trick because theres not much water to dry up