Draining a Closed Tank
Draining a Closed Tank
(OP)
Supposing you had a tank mounted to the outside of a submersible vehicle.
The tank lid is left open, and the vessel that taken down to 200m sea water depth, to top of tank.
The tank lid is now closed at this depth; it is assumed that the tank is completely full, with no air gap/bubble on top.
The interior atmosphere of submersible vehicle is at normal atmospheric pressure (1 bar). If the valve on the bottom of the tank is opened, how do you calculate the quantity of water that you can drain from the tank into the vessel (ignore pressure rise in the vessel due to the ingress of water) before the low pressure generated in the tank prevents further sea water egress?
http://files.engineering.com/getfile.aspx?folder=f...
The tank lid is left open, and the vessel that taken down to 200m sea water depth, to top of tank.
The tank lid is now closed at this depth; it is assumed that the tank is completely full, with no air gap/bubble on top.
The interior atmosphere of submersible vehicle is at normal atmospheric pressure (1 bar). If the valve on the bottom of the tank is opened, how do you calculate the quantity of water that you can drain from the tank into the vessel (ignore pressure rise in the vessel due to the ingress of water) before the low pressure generated in the tank prevents further sea water egress?
http://files.engineering.com/getfile.aspx?folder=f...





RE: Draining a Closed Tank
Independent events are seldomly independent.
RE: Draining a Closed Tank
Sounds like a homework problem to me/ What is the diameter of the drain piping into the submersible? Show your schematic/P&ID.
RE: Draining a Closed Tank
RE: Draining a Closed Tank
He'll get a lot more drops if he considers a possible temperature change, rather than the 20 bars he'll have from the 200 m depth. I suggest that 20 BarA to 1 BarA pressure expansion of 1m3 of water will only be about 1/2 of a teardrop. I always say everything, including water, is compressible, but the truth is that water isn't very compressible at all, least as far as the usual compressible things go. Maybe another 2 teardrops will be squeezed from the tank as it compresses from the exterior pressure, but we don't know the size, shape, or what the tank's made of.
Independent events are seldomly independent.
RE: Draining a Closed Tank
RE: Draining a Closed Tank
The outside water pressure will be somewhere around 6atm, for a fraction of a second ,there will be an 80psi spurt of water until the pressures equalize.
Unless the tank is made from a material so thick ,it cannot expand or contract.
B.E.
You are judged not by what you know, but by what you can do.
RE: Draining a Closed Tank
RE: Draining a Closed Tank
B.E.
You are judged not by what you know, but by what you can do.
RE: Draining a Closed Tank
Independent events are seldomly independent.
RE: Draining a Closed Tank
RE: Draining a Closed Tank
Independent events are seldomly independent.