The DeSat Method

Positive displacement pumps are required to transfer fluid to and from the vaporizer (vacuum chamber). In some cases, a vacuum is used to draw fluid into the unit. While this eliminates the input fluid pump, it reduces the capability of flow control. 

An incoming filter is common to remove solid contaminants and to keep the distillation column clean. Even more common is the use of discharge filtration for the final removal of solid contaminants. 

In some cases, to facilitate vaporization, heat must be applied either electrically or by steam transfer to raise the fluid temperature to the boiling points of the target contaminants. However, as previously mentioned, the inlet fluid temperature may be high enough without additional heating. 

A distillation column or chamber is required to

 separate the volatile liquids and gases from the

 fluid. The primary objective of the distillation

 column is to create a high surface area with the

 contaminated fluid, allowing ready effervescent vaporization of the contaminants. 

Several different processes are used, including atomizing the oil under pressure, passing the oil over several rings or saddles, thinly dispersing oil over a rotating surface, passing oil inside-out through glass-fiber cartridges, and passing oil through a column of reticulated porous media. 

Some commercial designs allow the water to coalesce first so that it more freely releases from the oil matrix and polar oil constituents (additives, contaminants, etc.). 

A vacuum pump is needed to exhaust trace amounts of non-condensed vapors and non-condensable gases to the atmosphere. A variety of rotary vacuum pumps are used to maintain a wide range of pressures in the vaporizer depending on the properties of the volatile contaminants. 

Suitable gauges for monitoring and control must also be provided to maintain efficient operation.