B Can a Subsea Lifting Bag With CO2 Rise to the Surface?

AI Thread Summary
A subsea lifting bag filled with CO2 can rise to the surface, as CO2 is less dense than water, but it requires more volume compared to O2 due to its higher density. CO2 has a density of 1.824 Kg/m3, while O2 is 1.331 Kg/m3, meaning approximately 37% more CO2 is needed to achieve the same lifting effect as O2. The discussion highlights that the buoyancy force from water is significantly greater than the weight of the gases, making the type of gas less critical underwater. Factors such as mass and drag forces also play a role in the lifting dynamics. Ultimately, while CO2 can rise, the efficiency and volume needed differ from O2.
cps.13
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This may sounds like a stupid question but...

If you were to use a subsea lifting bag filled with O2 it would rise to the surface.

Would the same happen with CO2? I assume the density of CO2 is different so the amount required would be more or less than O2, but it is still less dense than water so should rise?

Thanks

Edit:

After looking on google I can see that CO2 is 1.824 Kg/m3 whereas O2 is 1.331 Kg/m3. So you would therefore need 37% more CO2 to lift the same mass using O2.

Is that correct?

Thanks
 
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cps.13 said:
After looking on google I can see that CO2 is 1.824 Kg/m3 whereas O2 is 1.331 Kg/m3. So you would therefore need 37% more CO2 to lift the same mass using O2.

Is that correct?
No, it is not correct.
What is the density of water and how does that figure in?
 
There is a similar question, comparing Hydrogen and Helium for lifting power of balloons.
Take a look at this link about balloons (and lifting underwater).
 
I think we just have to consider that the O2 has mass. and the CO2 has mass. and we have to add that in. when its in that giant balloon. we can consider it to be its own object with a certian mass and a certian size (and extremely low mass). so let's just use 1m^3 volume.

I think the force from the water is going to be 1000 times greater than the weight of the O2 or CO2.
so the type of gas (while under water) has a really small effect.
 
I didn't account for F=ma or drag forces.
 
I think it's easist first to watch a short vidio clip I find these videos very relaxing to watch .. I got to thinking is this being done in the most efficient way? The sand has to be suspended in the water to move it to the outlet ... The faster the water , the more turbulance and the sand stays suspended, so it seems to me the rule of thumb is the hose be aimed towards the outlet at all times .. Many times the workers hit the sand directly which will greatly reduce the water...
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