Deoiling Hydrocyclones

The horizontal deoiling hydrocyclone vessel with liners is designed to reduce the oil content of the incoming produced water prior to entering an optional degasser vessel. The horizontal arrangement allows easy access to the liners for inspection, installation, and replacement.

Liquid/liquid cyclones – On entering the cyclone tangentially, the fluid begins to spin. This creates a radial force that directs the heavier phase towards the edges of the cyclone and then out of the cyclone underflow owing to differential pressure. The less dense phase is concentrated in the centre of the cyclone before passing out of the cyclone overflow, again due to differential pressure.

Hydrocyclones are effectively centrifugal separators that rely on the differential density between the oil droplet and the water to allow separation. The efficiency of the separation is governed by five main factors:

• Droplet/Particle Size
• Differential Density
• Viscosity of the Bulk Fluid
• Gravity (or Centrifugal Force)
• Distance

The reject from the hydrocyclone comes out in a counter current flow as a reverse spinning vortex. For an oil droplet to be removed it must make its way from the bulk fluid into the central core. The less distance the droplet must travel to get to this central core the higher the efficiency.