Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Deep water pump

Status
Not open for further replies.

3MM

Marine/Ocean
Jan 24, 2009
7
0
0
HR
I know that there are ballast pumps with capacity of 1000 cubics/hour and power of 7.5kW. Now, how much stronger it has to be in order to pump out water from for example tank which is situated at depth of 100 meters?
 
Replies continue below

Recommended for you

If you're dropping a submersible pump into the ocean to a depth of 100m, it will have 100 m of suction head and 100 m of discharge head + however much higher than the ocean's surface that you need to lift it. The first two 100 m suction and discharge heads caIf you're dropping a submersible pump into the ocean to a depth of 100m, it will have 100 m of suction head and 100 m of discharge head + however much higher than the ocean's surface that you need to lift it. The first two 100 m suction and discharge heads cancel, so you're just left with the head loss in the 100 m discharge pipe and the few m above sea level that I presume you do need to lift. In that case, not much extra power would be needed, as long as the discharge line size was a reasonable diameter.ncel, so you're just left with the head loss in the 100 m discharge pipe and the few m above sea level that I presume you do need to lift. In that case, not much extra power would be needed, as long as the discharge line size was a reasonable diameter.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)
 
Thank you for reply. I was not precise enough in my first post. I want to pump out water from tank which is on seabed at 100 meters not to surface but outside tank directly to the sea at 100 meters. It si not submersible pump because it's funcion would be to prevent tank to be overflowed (imagine that there is ingress of water in tank which must be pumped out) by water and therefore it can be regular ballast pump. Now, would this task demand too much power for pump in comparison to same task at lower depths?
 
If you want either a barge mounted compressor to fill the tank with air, or you want to locate a submersible pump in the flooded tank, and pump the water to the outside at that depth, then you'll need a discharge pressure of around 500 psi for either case.


**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)
 
What would be power input for pump with discharge capacity of 1000 cubic/hour and discharge pressure of 500 psi?
 
round about 1200 kW (1600 HP) ... more or less.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)
 
Status
Not open for further replies.
Back
Top