A drilling fluids treatment decanter centrifuge consists of a centrifuge bowl, screw, electric motors, gearbox, feed tube, solids discharge trough, fluids outlet port, bearing block, Ex control panel, cusions, telescopic skid or supporting legs. A decanter centrifuge used in drilling fluids treatment system is typically used to :
1)    separate fine solids up to 2 microns, to keep the drilling fluids balanced
2)    separate barite from used drilling fluids and reuse it
3)    dewatering the hydrocyclone underflow

As a decanter centrifuge manufacturer in China, GN solids control can produce decanter centrifuge models as below:
1.    drilling mud processing decanter centrifuge:
14 inch bowl decanter centrifuge GNLW363D for low gravity separation
18 inch bowl decanter centrifuge GNLW453D for low gravity separation
18 inch bowl decanter centrifuge GNLW452D for barite recovery
2.    diamond core drilling waste water treatment
9 inch bowl decanter centrifuge GNLW223D and GNLW224ET-VFD
3.    oil sludge separation, mud dewatering, solids liquid separation
14 inch bowl decanter centrifuge GNLW363D, GNLW364ET-VFD
18 inch bowl decanter centrifuge GNLW453D, GNLW454ET-VFD
22 inch bowl decanter centrifuge GNLW553D, GNLW554ET-VFD
30 inch bowl decanter centrifuge GNLW764A-VFD
To achieve better separation performance, hydrocyclones separation should be used before decanter centrifuge. The desander cone separation cut point is 45 microns, the desilter cone separation cut point is 15 microns, the solids content is reduced relatively then the fluids are transferred to decanter centrifuge.
For VFD decanter centrifuge, the G force can be adjusted by input different frequency ( to adjust the rotation speed) when bowl diameter is fixed. The high G force up to 3000G will reduce solids conveyance due to torque limitations. The higher of the G force, more solids will be settled in the bowl, more torque is required to move the solids out, until torque limitation is reached, the centrifuge stopped working due to torque protection.

Screw conveyor is normally used to transfer the drilling waste from solids control equipments to vertical cuttings dryer or high G drying shaker, or collect drilling waste from collection hopper and transfer to other place. The main components including: motor, coupling, gearbox, cover, hanging bearing seat, header of the driving end, screw shaft, blind flange, housing assembly, etc. The drilling cuttings is fed into the screw conveyor and transferred along with the rotating screw, the screw is sealed inside the trough by a hinged metal lid which is bolted down for safety, the feed port and discharged port can be designed as per client’s requirement.

Maintenance of the screw conveyor:
Compared with sludge vacuum pump, the operation and maintenance of the screw conveyor is easier, the vacuum pump operation need air compressor for air supply, the valves need to be checked regularly, the inlet hose and discharge hose length will be customized according to suction and discharge length required. The suction depth should be within the limit to ensure the performance of the vacuum pump. The maintenance of screw conveyor including bearing lubrication, gearbox oil level checking and gearbox regular checking, oil seal replacement, electric motor checking, etc. Under different ambient temperature, the grease lubricated should be used for different model. The screw conveyor can be installed horizontally or declined by installed different support frame. It can be installed under the solids control primary shaker along with shale shaker tank, the drilling cuttings are transferred by screw conveyor to the 2nd screw conveyor , which is installed slantly, it will transfer the drilling cuttings to vertical cuttings dryer or high G drying shaker.

The user can select to use screw conveyor and sludge vacuum pump depends on its location and area dimension, sometimes both of them can be used together.