2 replies to this topic

[Pierrot105]

Hello,

 

We are considering an increase of water flowrate on our installation, so much that we will exceed the electrostatic coalescer capacity (flooding the electrodes). In fact, the oil separates easily, and the electrodes are regularily switched off for various reasons.

 

What would be your advice to maximise the water outlet quality? could some internals replace the electrodes?

I don't mind the oil outlet (the water will settle in the tanks downstream).

 

Currently the inlet is distributed along the length of the coalescer, along the centerline. The oil and water are collected at top/bottom with collectors running along the length of the coalescer.

 

Thanks in advance, PB

[Bobby Strain]

So, why not just unplug the electrodes?

 

Bobby

[Technical Bard]

What is the ratio of oil and water?  What is the oil gravity/viscosity?  What temperature are you at?  Is there any gas evolving?   You can check the droplet size separation using Stokes law, and calculate droplet settling velocities versus the bulk fluid velocity.   See Chapter 13 of ASTM Manual 58.  

 

Electrostatic devices are necessary to help coalesce small water droplets in the oil.  If your oil is low viscosity, high API gravity and you aren't trying to meet a 0.5 BS&W (or lower), then you might not need electrostatic.  I am surprised by your acceptance of decanting water in the sales oil tank - most people don't want the hassle.