Definition - What does Desilter mean?
A Desilter is a hydroclone that is used to remove sand particles which have a grain size of 20 microns or less. Hydroclones operate on the basis of centrifugal force such that the mud with smaller particles is returned to the active system while the larger particles are discarded. The usual size of a desilter is 6 inches and above, however, the most common size is 10 inches.
Petropedia explains Desilter
Desilters are similar to desanders with the only difference in the size of sand particles that are removed by two devices. Desilters remove sizes which are 20 microns or lesser whereas desanders removes the sizes from 50 to 70 microns.
Desilter just like a desander is a part of solid control equipment on the drilling facilities. It is a hydroclone whose primary function is to remove sand and silt from the drilling fluids in the drilling rigs. The installation position of desilter is downstream from the desander in the surface mud system.All those solids that are not removed by a shale shaker are removed by a desander. Further the smaller size of granules lesser than 20 microns are removed by the desilter. Desilters also do not have any moving parts and the removal of sand and silt from the drilling fluid is done by the centrifugal force on the desilter.