Differential pressure vs flow rate(oily produced water)

[anji71]

I want to install a sisdestream unit between 2 pipes that requires at least 12L/min of flow. The D.P across the pipes is 2.5 bar, which should give me the required flow.
At the moment the flow is restricted to about 1-2L/min.

The only thing I can think of that is restricting my flow is a faulty 2" non return valve that may have blocked up on the discharge side.

I've checked the flow meter and also the flow downstream of the NRV seems to be greater than 12L/min when I open up a drain line to atmos.

Any ideas as to why this may be?

 

[25362]

It is not clear to me: what flow is restricted to 1-2 L/min, is the sidestream unit already installed ? If so, what kind of unit is that ?

A 2-in Sch. 40 pipe would pass 12 L/min clean water with a pressure drop of ~0.04 ft water/100 ft pipe. The presence of an oily emulsion could result in a higher viscosity of the fluid and increase the pressure drop.

Would you tell us the pressure of the line at present, when passing 1-2 L/min, and when draining 12 L/min to the atmosphere ?

 

[anji71]

This is a microbial biostud unit with 1/2" piping from a 12" produced water line. The inlet pressure is 12 bar, and the discharge is 10 bar. The flow meter d/s of the sidestream shows 2L/min at 12 bar. When you open the drain line on the outlet side of the unit which is fed into the 10bar line the pressure does drop to 10bar.
Also when you open up the drain line on the suction side of the unit the pressure drops to 5 bar.

The produced water has only a 700ppm oil content.

 

[25362]

A 1/2-in sch 40 clean pipe could pass 12 L/min water with a [Δ]P of about 10 ft water per 100 ft piping length.
Inlet + outlet + valve would add about 3 ft of water.
Where is the 2-in suspected NRV located ?

 

[anji71]

The 2" NRV is located at the discarge side of the pipe(10 bar) to a 2" offtake pipe to the 12" main line.