Definition - What does Desander mean?
A desander is a type of mud recycling equipment that is designed to remove solid particles ranging in size from 40-50 microns from drill fluid (mud). This process is accomplished through a collection of hydroclones that use centrifugal force and screens that filter out particulates that are found in the drill fluid after leaving the annulus. It is placed in line after the drill fluid has passed through the shale shaker and degasser, but before the desilter, mud cleaner, centrifuge canter and mud agitator.
Trenchlesspedia explains Desander
The size and number of hydroclones on a desander depends on the volume of the mud system; various sizes of hydroclones are available. A hydroclone has no moving parts, using only the geometry of the hydroclone itself and the velocity of the mud flowing in through the side to filter out heavier matter through the bottom and the lighter liquid up through the top. Both desanders and desilters, which filter out material 15-25 microns in size, are installed above a mud tank and may be combined into a single piece of mud cleaning equipment.