HP air Bottle Sizing Problem?
HP air Bottle Sizing Problem?
(OP)
Senario-1
I have a tank of Volume = 4.19 Cubic meter which is filled with water. Thank has an opening of 200 mm (0.2M) at the bottom of the tank also known as Flood ports. I want to empty the tank by giving a HP air blow at 10 Bar. How much air is required to empty the tank completely.
If someone can give any formula or any reference that can help me.
Senario-2
I have a tank of Volume = 4.19 Cubic meter which is filled with water and the tank is dipped in water at a depth of 5 meter depth. Thank has an opening of 200 mm (0.2M) at the bottom of the tank also known as Flood ports. I want to empty the tank by giving a HP air blow at 10 Bar. How much air is required to empty the tank completely.
If someone can give any formula or any reference that can help me.
I have a tank of Volume = 4.19 Cubic meter which is filled with water. Thank has an opening of 200 mm (0.2M) at the bottom of the tank also known as Flood ports. I want to empty the tank by giving a HP air blow at 10 Bar. How much air is required to empty the tank completely.
If someone can give any formula or any reference that can help me.
Senario-2
I have a tank of Volume = 4.19 Cubic meter which is filled with water and the tank is dipped in water at a depth of 5 meter depth. Thank has an opening of 200 mm (0.2M) at the bottom of the tank also known as Flood ports. I want to empty the tank by giving a HP air blow at 10 Bar. How much air is required to empty the tank completely.
If someone can give any formula or any reference that can help me.





RE: HP air Bottle Sizing Problem?
You want to displace 4.19m3 of water, so that's how much air you need - final pressure will be whatever head you are pushing against - in the second scenario approx 0.5Bar if the bottom of the tank is at 5m below water surface. You can work that back to determine what volume of 10Bar air you require. You would need to allow to lose a bit of air to get the last of the water out.
That's it in very simple terms anyway.
Cheers,
John
RE: HP air Bottle Sizing Problem?
You need to specify more data to define your problem: pressures and deltap in lines upstream and downstream, required maximum time to empty the tank and perhaps more (e.g.how is the port closed before starting? in how much time will it be opened?).
And of course your tank needs to be stamped for a design pressure of 10 bar, unless you can calculate a lower pressure will be reached at the maximum rate of air inlet. The tank could also require a safety valve.
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RE: HP air Bottle Sizing Problem?
In the scenarios described, an overpressure is required otherwise you would just be able to drain the tank by gravity in Scenario-1. As you point out though there is not really enough information provided to give meaningful advice - on reflection it seems to more the sort of problem one may get in high school.
RE: HP air Bottle Sizing Problem?
Let me elaborate a little bit more.
I have a tank of Volume = 4.19 Cubic meter which is filled with water. Thank has an opening of 200 mm (0.2M) at the bottom of the tank which will remain open always.
There is a vent opening at the top which can be controlled by a solenoid valve. When the vent is open the tank will sink and reaches 5 meter depth below surface and at that time vent is closed by a solenoid valve.
Then there is a pipe for blowing at 10 bar inside the tank for blowing out the water in tank and to raise it to surface.
Outer pressure or back pressure at 5 meter depth is 0.5 bar.
I want to repeat the process for 2 or 3 times so how much volume of air will be required ?
RE: HP air Bottle Sizing Problem?
Will the tank be actually full of water when it has sunk to 5m depth?
Will it start to rise before all the water is expelled (and so reduce the back pressure experienced by the air)? Tank weight will play a part there.
Each cycle will consume less air than would be calculated by the method described in my first post though, if the tank is not full of water when it is at 5m depth, and starts to rise before empty. Depends how accurate you need to know.
Cheers,
John
RE: HP air Bottle Sizing Problem?
The Tank will be completely filled at 5m depth.
and it will start rising as air will be blown into it.
RE: HP air Bottle Sizing Problem?
Dan
www.eltronresearch.com
Dan's Blog
RE: HP air Bottle Sizing Problem?
Not sure what shape the opening is in the bottom, but overpressure is not likely if it's a round or square 200mm hole.
Cheers,
John
RE: HP air Bottle Sizing Problem?
you people did add a valuable knowledge to me.
its really a serious problem. may be we are missing something which may cause problem during practical demonstration.
thanks