Venting liquid from a bottle question.
Venting liquid from a bottle question.
(OP)
I am working on a project, where I am pouring liquid from a bottle with a lid on it. I need a vent hole to allow the liquid to escape from the bottle. Is there a way to calculate how big my vent hole needs to be to get the maximum volume out of my bottle?
Thanks,
Steveaa123
Thanks,
Steveaa123





RE: Venting liquid from a bottle question.
I am pouring liquid from a bottle with a lid on it. Remove lid, it will help tremendously.
Is there a way to calculate how big my vent hole needs to be to get the maximum volume out of my bottle? Volume of the bottle should remain constant regardless of vent hole. Perhaps you mean flow which would be volume/time.
My apologies if English is your second language. Match your volumetric flow rates for fluid leaving the bottle and air entering the bottle.
RE: Venting liquid from a bottle question.
This is my first time at using this website. I am a Tech support and I have never worked with anything like this before. So, sorry for not sounding like I know what I am talking about.
My current project requires that I understand the relationship between liquid flow and the vent hole in a corked bottle. My task is to find the smallest vent hole that would not affect the flow rate of the liquid.
Thanks again for the help.
Steveaa123
RE: Venting liquid from a bottle question.
I suggest one first calculates the max liquid flow rate through an orifice for an assumed open container. There are formulas to estimate just that. Then, as suggested by Zapster, equate this flow rate to the flow rate of air required to enter the container. Using an expression for the known flow rate of air through an orifice, you should be able to evaluate different vent hole sizes until you find the required pressure difference is negligibly small.
RE: Venting liquid from a bottle question.
And I suppose that you don't want any pressure drop through the venting orifice. Otherwise it would be restricting some from by changing the pressure differentials accross the fluid orifice.
RE: Venting liquid from a bottle question.
First write the gas law
PV=WRT and taking one derivative
1)V*dP/dt+P*dV/dt=RT*dW/dt
Next the flow of fluids
2)dV/dt=kA2(-Pat+P+Rho*h)^.5 for liquid flow out(assumes bottle held upright and h is the height of liquid
3)dW/dt=RhoAir*K1*A1*(Pat-P)^.5 air flow in
Finally, the rate of height change
4)dh/dt=-dV/dt/Ab
Ab = area of bottle crossection
variables are P,V,h,W
parameters are A1 and A2
You should be able to solve this set by assuming some allowable flow rate to get A2, the air vent
Good luck
W/dt
RE: Venting liquid from a bottle question.