Downtime and high operating/maintenance costs resulting from water in diesel and turbine fuel have plagued industry for years. Solids and dirt could be removed by simple filtration but suspended water had to be removed by either high speed centrifuging or by allowing the water to settle out over an extended time period.
Through a process utilized in the Specific FS-2000 series Filter/Separator called "coalescense", it is now possible to remove all water, free and/or emulsified, by filtering alone. The Specific FS-2000 series Filter/Separator is designed to permit diesel engines and liquid fueled gas turbines to operate over long periods without fuel associated operational and maintenance problems. If the FS-2000 series does not meet your required needs Specific can design and build a fuel filter separator to your custom needs. Contact our sales department and they can help you.
Principles of Operation
The Specific FS-2000 series Filter/Separator is a coalescing type filter that utilizes two basic properties of liquids - inter-facial tension and preferential wettability for certain materials.
Interfacial tension is the characteristic that causes liquid droplets to assume a spherical shape. In a liquid of lower surface tension (such as hydrocarbon fuels) a water droplet contracts into a shape having the smallest possible surface area - that of a sphere. If two small water droplets come into contact, they readily join and form a single sphere because the single sphere, though larger in diameter, is less than the total area of the two smaller spheres. These water droplets will continue to combine into larger, more easily separated bodies, so long as they can be brought together.
Wettability is a measure of the attraction between molecules of a liquid and a solid. If a liquid droplet deposited on a solid surface spreads to a thin film, the attraction of the molecules of the solid surface is greater for the liquid molecules than that of the liquid molecules for one another. The solid is then said to be "wetted" by the liquid. When two dissimilar liquids such as oil and water, each of which is capable of wetting a given surface, are placed in contact with that surface, one will be more strongly attracted to the solid molecules than the other liquid and will displace the less strongly wetted liquid. The solid is then said to be "preferentially wetted" by the more strongly attracted liquid.
The Specific FS-2000 series Filter/Separator coalescing filter is a carefully designed application of materials, shape, pore size, and surface area such that interfacial tension and preferential wetting are exactly combined to accomplish the desired results.
The Specific FS-2000 series Filter/Separator is provided in two sizes and in either a simplex or duplex configuration, depending on the user's prime mover operating cycle. Where continuous operation is required, the duplex model will permit servicing the filter without shutting down the engine or turbine. The FS-2000 series Filter/Separator will remove all water from diesel or distillate turbine fuel, and can handle large slugs of water. All solids of 5 micron size or greater are also removed from the fuel. The filter/separator has no moving parts and requires no power supply.
The filter/separator unit consists of a fabricated steel shell with removable end cover, inlet and outlet connections, manual drain valve, vent valve, water level indicator glass with block valves, and the necessary internal element supports and seals. The filter utilizes filter/separator elements specially designed for the intended service, and which have a large dirt storage capacity which is not released through pressure fluctuations. Two pressure gauges are provided and indicate fuel entering pressure and fuel discharge pressure. Maximum permissible pressure drop for efficient filter operation is 20 psi.
The filter shell is thoroughly cleaned following fabrication and pressure test, sandblasted to near white metal, and coated inside and out with two coats of epoxy paint specially formulated to resist the fluid handled and to protect the filter/separator from environmental corrosion.
When duplex filter/separators are required, the two units are mounted on a heavy fabricated steel base assembly. All necessary interconnecting piping and valving is provided to points of common inlet and outlet. The valving permits fuel flow to be directed to one unit while the other is being serviced with new filter elements or is in the standby mode.
- Duplex design - two filter/separator units are provided on a steel base with all required piping and valving to points of common inlet and outlet.
- Differential pressure gauges - a single differential pressure gauge is provided on each vessel to indicate pressure drop across the filter elements and serve as a guide for filter servicing.
- Differential pressure alarm - a differential pressure switch is provided to permit the user to sound an alarm or shut down the engine or turbine when the pressure drop across the filter element exceeds 15 psi.