Tag Archives: Drilling Mud Desander

Desilter is the third class equipment in solids control system, it is used to separate the solid particles whose diameter is 15-44μm from drilling fluid. The desilter produced by DC Machinery has the advantages of large handling capacity, high separation ability and convenient operation.


The important problem is how to install it.

A The outlet and inlet connected by 6’’sebific duct, there is a pore on the top of overflow pipe to prevent desilter produce siphoning functionary. In order to don’t affect desilter regular work, we should not block the air-bleed hole, because it will have little drilling fluid outflow when desilter works, when it works shouldprevent desilter bleeder pipe blocked to avoid influence it normally work.
B The two ends of inlet pipe and overflow pipe all connected with flanged, and guarantee all can ingress or egress drilling fluid, in order to 8’’sebific duct caninstall in the other tank, the joint of overflow pipe can extend to any angles of axis spinning.

C Before operate desilter should open the screen box fixed device.
D The outlet pressure of centrifugal pump is the key of adjustment desilter.
E We must note when install screen, because screen installation directly influence screen service life, if can’t well install will damage screen. When install screen shouldn’t too loose and too tighten, if too loose, screen and supporting adhesive tape will have panting when shale shaker works, screen will rapidly damaged. If tootighten, screen forced too big can damage serious even tear the screen.
F Using retaining mechanism, it used to lock the screen and tighten scroll.
G We should notice the screen maintenance, don’t use spade and other hard scrape, hit screen, and according to different drilling fluid use different mesh screen.







Desanders are used to remove suspended solids from liquid process streams. One of the primary applications is to improve the quality of waste water. Treatment of waste water normally involves multiple process steps to remove the impurities and ensure that the final effluent discharge is compliant to regulatory specifications.

Desander cones

A desander has an entry port near the top on the side of the vessel, a hydrocyclone central component, and two discharge points (one on the top of the vessel and one on the bottom). The hydrocyclone is oriented so that the wide opening is at the top and the narrow opening at the bottom.


Hydrocyclones are designed according to the efficiency of solids removal required and the flow rate of the product stream. A typical waste water desander will remove particles with a mean of up to 10 microns. Any flow rate can be accommodated by appropriate sizing of the hydrocyclone design.

Waste water screens are sometimes used upstream of desanders to remove large items such as rags and bolts, and protect the cyclones from damage. A desander can operate for up to 10 years if properly protected and maintained.

Desanders should be used in unweighted mud when shakers are unable to screen down to 140 mesh(100 micron). The role of desanders is to reduce loading downstream on desilters. Installing a desander ahead of the desilter relieves a significant amount of solids loading on the desilter and improves its efficiency. High rates rates of pretration, especially unconsolidated “surface hole” where the largest diameter bits are used, results in generating larger concentrations of drilled solids. This may place desilters in rope discharge. For reason, desanders which have greater volumetric capacity and can make separations of coarser drilled solids are placed upstream of desilters.


Desanders remove a higher mass(coarser drilled solids) during periods of high solids loading. Desilters can efficiently process the reduced solids content overflow of the desanders.

If the drill rate is slow, generating only a few hundred pounds per hour of drilled solids, the desander maybe turned off drilled solids, the desander maybe turned off and the desilter used to process the entire circulating system.

Desilter should be used on all unweighted water-base mud. These units are not used on weighted muds because they discard an appreciable amount of barite. Most barite particles fall within the silt-size range.

Desilter operation is important for all unweighted fluids, however, in oil-based muds with high viscosities( as found in deep water drilling) the apex discharge maybe centrifuged for” oil-phase” salvage.

Hydrocyclones should process all drilling fluid entering their suction compartments independent of the drilling fluid circulation rate.