Blue Flower

Dewatering unit is actually a mixing system for flocculant fine solids in drilling mud. The real function of dewatering unit is flocculation. After flocculation, very fine particle polymerized into bigger sizes suitable for centrifuge separation.

2 Kinds of chemicals normally be used for flocculation in dewatering unit: PAC & PAM. Chemical is dosed from hopper on top of mixing tank. Normally, customer choose 3-chamber dewatering unit.

dewatering unit

Functions of the 3 chambers:

1# Chamber: chemical mixing,

2# Chamber: chemical Slaking,

3# Chamber: after mixing and slaking, the prepared material stocked in 3# chamber for usage.

Chemical transfer pump: suck chemical from 3# chamber and feed to decanter centrifuge.

Decanter centrifuge in dewatering unit: There are 2 feed pipes to dewatering centrifuge: One pipe is chemical feeding pump. Another pipe is screw pump feeding mud to centrifuge. Before the mud enters into centrifuge, it is mixed with flocculation chemicals.

If chemicals request a certain time to mixing thoroughly with mud, bend pipe will be used for centrifuge feeding. In this case, chemicals and mud can be mixed well before centrifuge treated.

After treated by decanter centrifuge: solids phase above 2~5 microns will be discharged from solids side. Water phase collected for further treatment.

After dewatering unit and dewatering centrifuge, fluids phase can be transferred to sewage treatment plant for further treatment. But it cannot be discharged into environment directly. As dewatering unit is a physical separation process. It utilizes flocculation function to make fine particles in bigger size, and then use high speed centrifuge force for separation. There still small amount fine solids (smaller size than 2~5 microns) and other chemical material.

Features of baby centrifuge
GNLW223 is a small size baby centrifuge. It is a decanter baby centrifuge specially designed for small capacity, small footprint, and used for fine solids separation with high speed.
Applications of baby centrifuge
This small size baby centrifuge have many applications, it can be used for drilling waste management system in some cases, the high speed is suitable for slurry separation, it is especially good for mining industry, diamond drilling and CBM drilling.

 baby centrifuge for CBM drilling

Models of GNLW223 baby centrifuge for CBM drilling, diamond drilling
1) GNLW223G: It is the basic baby centrifuge model. With fixed high speed up to 4900rpm. It is fixed speed with belt drive, means driven by electric motors.
2) GNLW223VFD. It is a variable frequency drive centrifuge with variable speed. It is control by PLC smart control system for VFD. The control panel with touch screen and bottom for operation. Just like a big Blackberry mobile phone.
3) GNLW223FHD: It is a full hydraulic drive decanter centrifuge with variable speed control. They model we cooperated with a German company for the hydraulic drive system.

Parameters of GNLW223 baby centrifuge
Max. Capacity: 150 Liter/min
Normal capacity: 100Liter/min
Bowl diameter: 220mm
Bowl length: 660mm
Beach angle: 8o
Effluent port: 6 (Ajustable)
Max. bowl speed: 4900rpm / 0~4900rpm for VFD model
Typical bowl speed: 3800rpm / 0 ~ 3800rpm for VFD panel
G-force (typical): 1770

For more information of GN baby centrifuge model or other big centrifuge model, visit GN website or contact GN Group. .

GN Solids Control company now have 2 each 14’’ oilfield high speed decanter centrifuge for sale, with 15% price off. It is brand new centrifuges make per international high standard.

Application of GN 14’’ high speed centrifuge

GNLW363 centrifuge is the most popular decanter centrifuge model for oilfield. It can be used in both mud solids control system, as well as drilling waste management system. Together with PLC smart control VFD panel, it can be used for barite recover and fine solids separation. It is the most suitable choice for LGS and HGS separation.

Parameters of GN 14’’ high speed centrifuge
Model:                         GNLW363G
Bowl Diameter:             360mm (14'')
Bowl Length:                1270mm (50'')
Beach Angle:                8°
Max. Bowl Speed:         3200RPM
Max Capacity:              30m3/h (132GPM)
Separation Point:          â‰¥2microns
G-Force:                      3060(Max)
G-Force:                      3060(Max)
Main Drive:                  37Kw-4p (50hp)
Back Drive:                  7.5Kw-4p (10hp)
Control Panel:              Explosion proof (EXdâ…¡BT4)
Main Body Material:       SS316L
Screw Protection:          Tungsten alloy tile
Solids Discharge Port:    Interchangeable tungsten carton alloy ring

Why GN 14’’ oilfield high speed centrifuge for sale with 15% price off

It is exactly brand new centrifuge in stock. It is GN old design with 2 motors (main motor and back drive motor) located in the two ends of the centrifuge. From 2014, GN updated the design with 2 motors mounted in the same end of centrifuge, for a more compact design. The centrifuges for sale is the last 2 sets with old design. (Every time, GN make 10 sets centrifuge as one batch). It is made per GN high standard for international high speed, with SS316L bowl material, original SKF bearing, tungsten carbon tile for screw protection…

For more information of GN decanter centrifuge model, send mail to This email address is being protected from spambots. You need JavaScript enabled to view it. or call at +86 18632565675

Applications of GN made Drilling Cuttings Processing System
GN Drilling Cuttings Processing System can be used to treat various kinds of drilling cuttings from drilling mud solids control system, such as oil based drilling cuttings, water based drilling cuttings, synthetical based drilling cutting.


Features of GN made Drilling Cuttings Processing System

The processing system is including a vertical Cuttings Dryer and a Solids Control decanter centrifuge with variable frequency control.
The solids control centrifuge is lifted by telescopic skid. Solids discharged directly, as the skid height is higher than normal solids control mud storage tank. The clean fluids can be leaded to mud recycling tank for reuse.

There is a small transition tank between cuttings dryer and solids control centrifuge. All equipment as well as the transition tank mounted on a big skid. The skid can be the same dimension as 40ft container, can put on the trailer for fast movement.
Another side, the tank skid can be moved smaller than 40ft container and put into container for international shipment.
GN made Drilling Cuttings Processing System is widely used in U.S.A, Russia, Indonesia, Argentina, Algeria, Tunisia, Nigeria, Egypt, Romania, Kuwait, Saudi Arabia, Iraq, Oman, Qatar   
For any questions regarding drilling cuttings processing system, you can contact GN group for customized solution.

A conical bowl centrifuge is shaped just as it sounds. The interior of the bowl is a cone. These were the original centrifuges used in the oilfield and some are still used today.

An advancement in centrifuge bowl design was the contour or cylindrical design. In this design, the large diameter of the bowl is kept cylindrical for a portion of the total length, then transitions to the normal angle of cone taper for the remainder of the bowl.

When comparing conical and contour bowls of the same length, several things happen. If the pool is adjusted so that the beach is the same on machines, the pool volume and therefore retention time is greater on a contour bowl. The result is that a contour bowl can handle a much higher feed rate while still making the same median outpoint, as compared to a conical bowl centrifuge of the same size.

decanter centrifuge

Decanter Centrifuge Applications in Solids Control System

For drilling fulids processing there are two uses of centrifuges. One is to remove solids from the mud while returning the liquid phase to the active system, such as when used with an unweighted drilling fluid. The other is when solids are returned to the active system and the liquid phase is discarded.

For unweighted drilling fluids, a centrifuge is often used on the active mud system ot remove as many drilled solids as possible, which helps to control the weight or density of the mud. The effluent containing colloidal solids, such as bentonite and chemical additives, is returned to the active mud system. If it is an expensive drilling fluids, often the hydrocycone unders can be processed with a centrifuge to recover as much of the associated liquid phase as possible while discharging the solids.

Decanter centrifuge is usually installed after the desilter. The drilling mud from the desilter is pumped through the inlet to the feed chamber and slung from the feed ports into the pool. It is accelerated again with a high shearing effect due to the rotation of the bowl. The level of the pool is determined by adjustment of the weirs at the large end of the bowl (effluent discharge).
As the slurry flows through the pool in the channels between the conveyors flights, the particles settle according to Stocke's law, but at an accelerated rate due to the higher G forces. Sand particles settle almost instantly, then the finer particles settle. The particles that cannot be settled under the existing settings of the centrifuge will discharge out the overflow with the liquid phase (effluent).

Decanter centrifuge for oil sludge treatment


The screw conveyor rotates in the same direction as the bowl, but at a slightly slower rate. This difference is determined by the gear box. Typical gear boxes are 80:1, 125:1, 40:1, and 52:1 gear box. 125:1 means that for every 125 revolutions of the bowl, the conveyor turns one less or 124. With this ratio, a centrifuge rotating at 1800 RPM has a conveying speed of 1800/125=14.4 RPM.
The settled solids from a cake on the side of the bowl and are conveyed along the outer edge of the pool towards the solids end (small end) of the rotating assembly and are discharged out the solids discharge ports at high velocity. As the solids travel across the beach, they lose their free liquid film due to centrifugal squeezing and drainage. They are discharged with only the absorbed moisture; provide the centrifuge is operated properly.
This discharge cake is very heavy, and sticky. It will not flow because of the lack of free liquid. It is important to realize this when installing a centrifuge. If possible, install over the place where the solids are to be discharged. If this is not possible and this slide so that it will self clean. If this is not possible, then some sort of mud wash or water wash will be needed to keep the solids from building up and packing off the centrifuge. Another option is a small amount of remix water added within the bowl housing directed at the solids discharge to softed the slurry. Remember to have the solids directed towards an mud agitator to keep the solids from simply dropping to the bottom of the mud tank.