Motion Insensitive Flotation

With the increased use of floating production facilities, the motion experienced by flotation devices

Figure 6 Single cell ISF. Courtesy of Baker Hughes Process Systems.

inhibits separation. A 2° tilt results in one end of a 12 m long flotation machine being approximately 350 mm higher than the other end of the vessel. This results in one end of the machine flooding while the other end will not remove floated oil. To overcome this problem, one manufacturer has designed a flotation column ISF machine that reduces the impact of pitch and roll to 10 mm at 2° tilt.

The method of bubble generation (eduction) is the same as that used for the four-cell ISF. Sparging was investigated as an alternative, however the bubbles were larger and moved in a linear fashion to the surface. Educed air forms smaller bubbles and exhibits random movement. Both these latter characteristics are desirable as they increase the chance of an air bubble-oil droplet collision.

Since the single-cell ISF has one rather than four cells, theory would predict that its contaminant removal efficiency would be reduced from approximately 90-98% for a four-cell unit to 80-90% for a single cell unit, primarily because the residence time in the single cell unit is some 65% of that in the traditional four cell design. In trials, however, the unit has operated successfully with inlet oil concentrations of between 50 and 1300 ppm, and suspended solids concentrations of 10-50 ppm, and has achieved oil removal efficiencies comparable to the four-cell model, taking into account the reduced residence time in the single cell. In service, actual efficiencies will depend on optimization of flow regime and chemicals (see Figure 6).

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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