Two units of GNLW553VFD decanter centrifuge and feed pumps are packed for delivery to Nigeria. The two units will be installed following vertical cuttings dryer in drill cuttings treatment system.

GNLW553VFD is “Soft Start” Variable Speed Drive Centrifuge with high volume processing up to 400GPM. The VFD positive pressurized cabinet enables low amperage start-ups and smoother rpm changes to minimise amp drain in the motor.

The single screw pump is an ideal transfer pump for feeding to decanter centrifuge without shearing or agitating the drilling mud. If you'd like to learn more about drilling waste management equipment, please view at www.gnsolidscontrol.com

Differential speed is the difference between the bowl speed and the conveyor speed. The differential is provided by the gearbox which transmits power from the bowl to the conveyor. This is required in order to transport the solid particles that collect on the bowl inner diameter using conveyor. The differential speed determines how long the solid particles remain in the bowl.

The differential speed is decisive for the time that the solid particles remain in the decanter centrifuge, and the compression that it undergoes. It is important and necessary to be able to set the differential speed variably, because changing drilling mud properties in the feed lead to differing conditions, and thus it is possible to keep the total dry solids of the solid at an optimum level. Many centrifuge manufacturers provide a “back drive” which can independently alter the speed. Back drive units are, in effect, hydraulic gear reduction systems used to vary the speed of the conveyor relative to the bowl.

Differential speed adjustment and its advantages

• The differential speed makes it possible to keep the solids in the decanter bowl for the ideal length of time
• Optimum dewatering with fluctuating feed conditions
• Optimum setting of the total dry solids that can be achieved
• Protection against overload and blockage
• Variably adjustable differential speed can make it possible to do the treatment of an extremely wide range of drilling mud

Screw blades spacing is the gap between two neighbouring blades. It is an important parameter for the structure of the screw, because it directly determines the ability to convey solids out of the fluids.

When screw diameter is fixed, the bigger the screw blades spacing, the larger the helix angle and the more chances of suspensions blocking in the screw blades. Big screw blades spacing will also reduce the number of screw blades cycles. The suspensions can not be distributed evenly and it will cause the machine vibrating unsteady.

Conclusion:
1) For suspensions difficult to separate and transfer, the screw spacing should be less, in general 1/5-1/6 of the decanter drum diameter, so that the solids can be transported successfully.
2) For suspensions easy to separate and transfer, the screw spacing should be larger, generally 1/2-1/5 of the decanter centrifuge drum, in order to increase the solids transferring capability.

GN553VFD big bowl big volume decanter centrifuge and screw pump are ready for delivery to Middle East. The centrifuge will be used in oil and gas drilling application. The centrifuge can be used for fine solids separation in drilling mud solids control system or for drilling mud recovery in drilling waste management system.

The screw pump we supplied to the customer along with the decanter centrifuge is NETZSCH brand. The single screw pump is ideal pump for transferring the drilling mud to the decanter centrifuge.