Suspended Solids Removal
Technical Profile
The objective of this process is the removal of rather coarse suspended solids that could deposit on cooling circuit equipment creating scale and corrosion sites.
Filtration with seawater strainers and coarse filters can typically range from less than 75 microns to 25 millimeters. Filter cleaning, accomplished using backwash, and is required when the differential pressure on the unit increases to the point of maximum or the flow becomes too restricted. Many units limit backwash volume and can be cleaned on-line.
The difference between strainers and coarse filters is small and one of definition. In simple terms, if particles to be removed are visible to the naked eye the process unit is said to be straining. If the particle is invisible to the naked eye, the process unit is said to be filtering. Particles are typically visible between 50 and 75 microns. Therefore, strainers typically remove particles above 75 microns while coarse filters remove particle less than 75 microns. Strainers and coarse filters are often used in sequence where the strainer removes larger particle that would clog the filter quickly. The filter is then free to remove finer particles longer before it has to be cleaned.
