1 reply to this topic

[ADR]

Hello all,

 

Need an input from you guys to bring an end to an ongoing argument with my colleagues. 

 

There is a tank in an offshore oil rig which contains low concentrated sodium hypochlorite (NaOCl) at an elevation of 10 metres from the mean sea level (MSL). The purpose of NaoCl is to prevent marine growth in the seawater lift pump / fire water pump caissons.

 

The pressure at the outlet of the tank is about 0.5 barg. The elevation of the tank's discharge nozzle from the MSL is 10 metres. Injection point is 50 metres below MSL.

 

As the caissons are flooded (correct me if I am wrong), my argument was a pump with at least 35 m TDH @ the required flowrate is required to inject the hypochlorite deep at 50m.

 

But a couple of my colleagues are disagreeing with me, they strongly believe that 0.5 barg at the tank's outlet is sufficient to inject the fluid 50m below sea level. The justification given to me was as the caissons are vertical, gravity will overcome the hydrostatic pressure on the caissons and force the fluid down to the bottom.

 

I believe their argument defies Pascal's law.

 

Please can any of you point out who is wrong here and provide me with a rational answer?

 

Thanks

[Bobby Strain]

 

No need for argument. You need to do some calculations that engineers routinely do when designing a pump system.

 

Bobby