In my research, I have encountered the following problem:
I have a vacuum pump that I would like to use aspirate water from below an elastic surface. The water resides under the elastomere and a tube, that is coupled to the vacuum pump, is connected to the surface of the elastomere where a hole is made for water to escape. The water pressure is not high enough to push out the water, so the vacuum is used as an assist to pull out the water instead. The tube is sealed completely other than its connection to the vacuum and the opening which is connected to the elastomere, so the environment within the tube should be considered a closed environment when the opening is connected to the elastomere and the vacuum is turned on.
The pump can generate a vacuum with an absolute pressure of 10 kPa. The vapor pressure of water at room temperature is 3.16 kPa. I know that if the pressure drops below the vapor pressure the water evaporates. Does this mean that the water will evaporate, as the vacuum pulls with a pressure that exceeds the vapor pressure? I mean the vapor pressure is a pressure gradient by water vapor that presses on the liquid water, while the vacuum is pulling against that liquid water in the other direction. Or am I misunderstanding some fundamental concepts here?
Thanks everyone for all the inputs in advance!
UPDATE:
I think I have figured it out but please correct me if I'm wrong.
So, what I have misunderstood is that it is not that the vacuum "pulls" the water with the pressure of 10 kPa. Rather, the vacuum generated within the tube has an absolute pressure of 10 kPa, meaning that within the environment of the tube, the air molecules will press on the water with 10 kPa (as opposed to 100 kPa at atm). Hence, the pressure of the vacuum is not low enough to evaporate (or boil) away the water, which would only occur if the pressure drops below 3.16 kPa.
