TBM centrifuge

GN dewatering centrifuge is working well for Tunneling in Singapore, our engineer just finished the first time installation and commissioning there and back to China. As per client’s request, our engineer can fly to the client’s site to support them for the first time installation, commissioning and training. If the equipments will work well or not, it will mostly depend on the proper maintenance and operation, we will train the client’s engineer how to operate it and how to do the maintenance.


The dewatering centrifuge system for Tunneling is to treat the waste mud / sludge/ water and reuse the water, the discharged solids should be dry enough to collect by bags then shipped by truck. The configuration is as below:
1) GNLW363-VFD decanter centrifuge is widely used for dewatering unit to treat the waste water
2) Chemical dosing system/ flocculation system
3) 20ft container with windows and doors.
4) Netzsch brand screw pump as the feeding pump of decanter centrifuge, which is the ideal feeding pump to control the frequency to control the flow rate, compared with centrifugal pump and slurry pump, it works more steadily.


Before feeding to the decanter centrifuge, we suggest the client to use a screen/ filter or high G drying shaker / desander / desilter before the dewatering centrifuge system, the purpose is to prevent course solids enter into the centrifuge and the screw will be damaged and centrifuge will be blocked. The core components of the centrifuge is the screw, GN centrifuge screw is completely made by stainless steel, and protected by tungsten carbide tiles, the fluids distribution port is protected by tungsten carbide alloy for wear resistant.

Since early this year in CIPPE Beijing, GN Solids Control firstly showed its big bowl decanter centrifuge GNLW764-VFD, the super bowl decanter centrifuge with a diameter of up to 30 inches, this centrifuge model got lots of attentions from the end users, especially from the construction work and piling projects. The large capacity and excellent performance is exactly what they want.

GNLW764-VFD

30 inch bowl diameter GN centrifuge

The big bowl centrifuge GNLW764-VFD has following features:
1. With a bowl of 7650mm long, while 3344mm as a bowl diameter, GNLW764 is promised to have a large treating capacity in order to be suitable for many applications.
2. Because for the large length diameter ratio, which is up to 4.4 and also a G force at 3000G by high speed rotating, this centrifuge could give a for a perfect separation result, a clearer Liquid phase after treatment.
3. Just as all centrifuge models GN provides, the liquid discharge port is easy to adjust. It helps operator to get a suitable dryness fraction by adjusting rotation speed, differential speed and liquid discharge ports.
4. Stable performance:all rotating part of the centrifuge are fabricated by five-axis machine, and well dynamic balancing tested at high speed to ensure a precise fabrication. Besides, theis model is also functioned with automatic lubrication.
5. Heavy load:GN employs a gearbox with 25000N.M torque for GNLW764-VFD for handling heavy load conditions.
6. Long service life:bowl material is duplex stainless steel SS2304 by centrifugal casting, YG8 hard tiles for impeller protection, and also YG8 material for liquid discharge ports and solids discharge ports. Genuine SKF bearings are used in order to ensure a longer service life.
7. Easy operation:with PLC smart control system,HMI visual operating screen, the operator can observe the on time working condition of the centrifuge. By adding more devices onto the centrifuge like temperature protection for bearings, vibration protection, overload protection and current monitor are all equipped fo this centrifuge, for a more convenient operation.

Centrifuges are equipment with high efficiency and various applications. Centrifuges with different sizes are used for different applications.

GN 30 INCH BOLW CENTRIFUGE ON JOBSITE

Like among the GN Solids Control’s centrifuge models, the fixed speed 14 inch diameter bowl GNLW363 series centrifuges and GNLW452 decanter centrifuge with 18 inch diameter bowl are widely used for the oil and gas drilling solids control systems for the barite recovery. The VFD controlled GNLW363G, GNLW453 and GNLW553 series decanter centrifuges are used for the drilling cuttings waste management when working with a GN high G drying shaker or a GN Vertical cuttings dryer which are respectively for WBM and OBM and drilling fluids treatment projects, when working together with a chemical dosing system. GNLW223 and GNLW224 decanter centrifuges are mostly used for the diamond drilling projects and some projects with small treating capacities.
GNLW764 decanter centrifuge is a newly designed decanter centrifuge with a 30 inch big bowl, and a length bowl ratio as large as 4. It is specially designed for the big TBM projects, working after the shale shaker and desander plant. In some clients’ jobsite, there are 2 parallel desander units, each including one GNZS594 shale shaker and a GNZS594-2S12N mud cleaner. All fluids after treated by the 2 desander unit are transferred to the giant decanter centrifuge. On inlet of decanter centrifuge, there is a set of GNDW2000 Dewatering unit, it is used for chemical dosing for the centrifuge. It has 3 chambers for adding different chemicals for flocculating the extra fine particles into bigger ones, in order to be separated out by the centrifuge. Although after flocculation, the decanter centrifuge’s treating capacity is greatly reduced, GNLW764 could still handle a large capacity upto 90 cbm per hour.
Except for the giant centrifuge, other sections of the system are all designed into 20 ft containers. Even the shaker and mud cleaner are in frames with container corners. It is easy for transportation and layout.
If you need more information, welcome to contact GN Sales team directly.

By using an efficient solution of the drilling cuttings waste management system and treat the solids well, the particles could be dryer and even reach the standards to be discharged, meanwhile, the expensive drilling fluids could be collected and put back to the drilling system.

GN DRILLING CUTTINGS WASTE MANAGEMENT EQUIPMENT

Ever since year 2013 when GN Solids Control firstly designed and put into reality the GNCD930 series cuttings dryer, GN has designed 2 kinds of drilling cuttings treating system, both combined by following equipment:
1. GNCD930 vertical cuttings dryer. It is like a drying step of a washing machine, by high speed vertical drying, the liquid phase, drilling fluid passes the mesh of the cone sized basket, while the solids phase, the cuttings, fall down to the discharge port. After treatment of GNCD930, the OCC could be less than 5%. And according to different cuttings condition, GN gives 3 optional mesh opening sizes. Clients could prepare all of the three for different conditions.
GNCD930 Vertical cuttings dryers are firstly designed for the OBM and SBM, but per some clients’ feedback, it could be useful for some water based mud, too.

2. After the GNCD930 vertical cuttings dryer, the drilling cuttings are collected while the drilling fluid falls into a container and to be pumped to next step, the GNLW363 series decanter centrifuges. GNLW363 series decanter centrifuges are the super star among GN centrifuge models. In every 10 sets of GN Centrifuges, 7 are GNLW363 decanter centrifuges. It has the medium size and more optional control panels for option. In solids control system, clients always choose fixed speed GNLW363, while in drilling cuttings waste management or drilling fluid treatment project, the VFD model with PLC control panels are more popular. In some none explosive conditions, clients could choose the more economic model, while in some countries and regions when IECEX or ATEX is a must, GN also have those models for option.

3. GNSC series screw conveyors. By providing screw conveyors of different diameters and length, GN has 12 models for option. Clients could choose per the transporting capacity and distance to be transported.

Diamond core drilling is one kind of drilling project which is similar with some small HDD or TBM drilling. But comparing with HDD or TBM drilling, although the requested capacity of the diamond core drilling is smaller, the separation standard is even higher.

core drilling mud system

GN compact solids removal unit

GN Solids Control has some mature solutions for such kind of drillings, and GN Solids Control has a group of compact designed separating equipment to serve in this system. This system is combined by a small shale shaker and a baby centrifuge, which are the most efficient separation equipments, and the cutting point could reach 2 to 5 microns. Besides the separation equipment, this system has a mixing unit also, which is used for adding more components into the system.
In this system, following equipment are included:

1. GNZS752E-DM shale shaker. This is a small shale shaker, suitable for the small capacity applications like the diamond core drilling. It has 2 pieces of shaker screens, with a screen area of only 1.35 cbm, only larger than half of GN normal shakers. But this capacity and mud routine is enough for the small projects. GN has a shaker screen factory for making composite material frame screens for this shaker model.

2. GNLW223-VFD decanter centrifuge. It is the smallest decanter centrifuge among GN centrifuge models. The bowl diameter of GNLW223 is only 9 inch, but the rotating speed could reach 4200RMP as normal operating speed.

3. Jet mixing hoppers for the mixing unit.

4. A tank for housing those above mentioned equipment and for receiving the liquid discharged from the equipment.

5. Centrifugal pumps respectively for feeding the decanter centrifuge and the mixing unit. GN centrifugal pumps are fully interchangeable with NOV Mission pump in both installation dimensions and spare parts.
Besides being used to the diamond core drilling projects, it is also used for some small HDD projects. For more information, pls contact GN Sales team.