Screw pump is also called as Progressive Cavity Pump. A screw pump is a type of rotary pump which is equipped with rotor and stator. The rotor and stator is combined together and rotate within a cylindrical cavity or liner. The fluid or transfer medium enters from the suction side of the screw pump and moves linearly along these intermeshing screws / rotors to the discharge side of the pump.

Screw pump is a popular feeding pump type for centrifuge, no matter for decanter centrifuge, 3-phase centrifuge, or disc centrifuge. Besides screw pump, submersible slurry pump and sand pump are also been used a centrifuge feeding pump. But as submersible slurry pump and sand pump are both a kind of centrifugal force pump, they are not as good as screw pump to feed for decanter centrifuge.

Decanter centrifuge is a high speed rotating device. There will be many self-protection function for safety and also for protect the device. A major self-protection application is over-load protection. It means in case the centrifuge feeding is over load, the centrifuge will be stopped to avoid damaging bearings or damaging rotating component. In this case, the feeding screw pump must be capable to adjust the feeding flow. There are mainly 2 ways to control the feeding screw pump input flow rate:

1) If fixed speed screw pump is used to feed for decanter centrifuge, a VFD control panel is requested to adjust the feeding flow rate to avoid over load, and to reach the better separation performance.

2) If manual adjustable speed screw pump is used as decanter centrifuge feeding screw pump. Fix speed control panel can be used for the pump for start and stop.

Furthermore, as the decanter centrifuge has self-protection function in case of overload. To avoid damage the centrifuge, there must be an inter-lock connection between the centrifuge control and the feeding pump control. In case the centrifuge is stopped, feeding pump can be stopped immediately. And the screw pump cannot be started until the decanter centrifuge is running stably.

GN Solids Control is specialized in drilling mud solids control and waste management solutions. GN Solids Control is capable to design and make Oil Water and Solids Separation System to treat and recover various kinds of waste materials.

GN Oil Water and Solids Separation Systems are capable to treat below waste materials, but not only limited to below materials:

1. It can be used to treat oil sludge and oil, oil contaminated soil remediation, like from drilling waste pits, or from pondsand tanks
2. It can be used for water oil contaminated water-control and recovery
3. It can be used to treat waste oil and recover the oil to reuse
4. It can also be used to treat waste oil, water and solids mixture, and to recover oil, water and reduce the solids waste

Oil sludge means the waste mixture consisting of oil, water and solids. Oil water separation system is used to treat the oil sludge in order to reduce waste material, and recover oil and water for reuse. The oil sludge treatment system is also a popular solution to treat oil contaminated soil and sands.

Oil sludge is a mixture consisting of oil, water and sands. The treatment on oil sludge would recover much oil and water for reuse. Also it is an ideal solution to for the solids disposal. More oil and water recovered, more energy and resource could be saved. GN oil sludge treatment products mainly include decanter centrifuge, oil water separators and thermal desorption unit.

As many customers did not do waste management system before. To ensure GN Oil Water and Solids Separation Systems can applied for their applications, GN Solids Control specially designed a one-skid compact Oil Water and Solids Separation System for trial purpose. GN one-skid Oil Water Solids Separation System is in stock for sale. Clients can buy the small system as trial base to show to their clients their capacity to do the projects. For clients in China, they can choose to buy or rent the one-skid system.

If clients do not want to buy the one-skid compact Oil Water and Solids Separation, they can send their oil sludge or waste material to GN Solids Control. GN Solids Control can do the separation at GN factories and show clients the performance. After separation, GN Solids Control can do lab test and show the final output specs to the clients.


Last week, several packages of Mud Cleaning System were shipped to Chinese sea port. The mud cleaning systems will be sailed to North America to service their mud cleaning projects. The project the client will do is that, they collect various kinds of waste mud and waste water from rigs or from construction field. The client transports the waste mud and waste water by vacuum trucks, and treat them together to reduce the waste material, and recover solids and waste for reuse. It is high standard mud cleaning system to suit for North America standard.

The features of the mud cleaning system are that, its design is very compact for small foot print. Several mud separation shale shakers and dewatering centrifuge unit are equipped in the system for better separation performance.

1) First separation is by double deck coarse shale shaker to remove the big size solids from the waste mud and waste water. The top of the shale shaker is covered by metal boards to avoid mud leakage during shale shaker vibration.

2) After the double deck coarse shale shaker, next separation is taken by a single deck high G force shale shaker. The same design as the double deck shale shaker, the top of the single deck shale shaker is covered by metal boards to avoid mud leakage during shale shaker vibration.

3) A package of dewatering centrifuge unit.

As there are still many fine solids particles inside the recovered water from shale shakers, a dewater unit is used in the system for chemical dosing. It is used together with a high speed big bowl decanter centrifuge for fine solids separation.
The mud cleaning systems can recovery as more sands from the waste water. Regarding the waste mud from hydraulic excavation drilling, the recovery liquid phase is usable mud for reuse. The separated sands can be used for construction material.

Last week, GN Solids Control got an inquire from a client regarding oil sludge treatment system. The client said they are a company specializing in the industrial cleaning works. They are intend to treat the sludge in oil comes from below field:

1) Waste tank bottom sludge, oily sewage generated by the crude oil tank;
2) sludge, oil sands or soil from oil pit of the refinery plant;
3) Waste oil-based drilling fluid or oil base cuttings produced by oil and gas drilling, etc.;

As part of the development of the client activity, and also they hearted about GN Solids Control before, they are interested in the acquisition of GN Solids Control Oil sludge treatment solution, for that they ask GN Solids Control to give them a suitable solution for (01) unit of sludge oil treatment plant . They want the oil sludge treatment system with capacity of 2 m3/h to 5 m3/h.

GN Solids Control confirmed with the client that, the material mentioned is their list is all inside GN Solids Control scope. Based on their requirement on handling capacity, GN Solids Control recommends the oil sludge treatment system model GNOST-05A, which can suit for the client’s capacity.

Major separation equipment in the oil sludge treatment unit is high G drying shaker, 2-phase decanter centrifuge, 3-phase disc centrifuge, dewatering unit, screw pumps slurry pump, mud agitators, etc.. .

The technology GN Solids Control is using is heating and chemical washing. The processing equipment in the system is GN core products which are sold well and performance good for many years.

GN Solids Control has many oil sludge treatment system running in China and outside China. GN Solids Control has projects reference in China, Canada, USA, Qatar, Kuwait, Kazakhstan, Indian, Indonesia, Korea, Poland, UAE, etc…
If you have any questions about sludge oil treatment, you want to get solution on sludge oil treatment, welcome you contact GN Solids Control.

This is the last working week before Chinese Lunar New Year holiday, after that offices and workshops will be closed for a 2-week holiday. All GN workers are working day and night in order to ship as more as orders before the 2-week holiday.

Some dewatering centrifuge units are dispatched to sea port, they will be exported to a Southeast Asia client. The dewatering centrifuge units will be used for TBM mud treatment. TBM is short for Tunnel Boring Machine, it has a wide application in railway, hydropower, transportation, mining, municipal and other tunnel projects.

Drilling mud is used to lubricate drilling bits during Tunnel and Boring drilling activities. For environment protection, the drilling mud and waste water must be recycled and reused during and after the drilling activities. Besides normal mud desanding plant, dewatering centrifuge unit is also requested in some application to treat the waste water.

GN dewatering centrifuge unit consists of big bowl big ratio decanter centrifuge, and chemical dosing unit. The decanter centrifuge and chemical dosing system is combined as a full package unit to remove as more ultrafine solids as it can do. The decanter centrifuge and chemical dosing system are both allocated inside a fabricated container. The full package can be shipped as a shipper owner container during international shipment. And the containerized design can protect the centrifuge and chemical dosing system, which values much. And they are easy for shipment between different jobsites.

Decanter centrifuge itself is a Physical separation machine. It can only separate solids by particle sizes. It cannot remove ultrafine solids smaller than the cut point. By chemical dosing, the ultrafine solids can be flocculated, and reach the centrifuge cut point for solids removal.

Besides dewater centrifuge unit, GN Solids Control makes full line desanding separation equipment for TBM and other trenchless no dig activities, like shale shaker, desander, desilter, etc…

Drilling cuttings solidification or stabilization unit is for the final treatment of drilling cuttings or waste sludge after the drying treatment. It is especially used to treat the drill cuttings treated by GN vertical cuttings dryer, and GN high G drying shale shaker, or decanter centrifuges.

A full package of GN Drilling Cuttings Solidification Unit is finished for production and inspected by international famous third party inspection company. The full package of GN Drilling Cuttings Solidification Unit is made for an Africa client. It will be dispatched to the sea port for exporting to the Africa client to complete his waste management processing system.

Drilling Cuttings Solidification Unit can use lime as curing agent, flyash and Cement kiln dust as filler to do the solidification. This apply to solidifying the inorganic pollutant, like Petroleum refining sludge, Heavy metal sludge, oxidizing material, waste acid etc. The curing agent and filler is easy to get; operation is easier and cheaper than cement solidification.
Drilling Cuttings Solidification Unit is composed of waste cuttings transfer system, mixing system, solidifying system, electrical control system, lighting etc. It can be used for transferring, mixing, agitating and solidifying of the waste cuttings.

GN Solidification unit is composed of Auger skip feeder unit, Single axis continuous Rotary mixer, variable speed control screw conveyor, electrical control system and ladder, walkway, handrails etc. GN Solidification unit is with compact design, reasonable layout; it is convenient for assembly & disassembly.

Besides Drilling Cuttings Solidification Unit, GN Solids Control design and makes all the full line solids control and drilling waste management equipment before the Drilling Cuttings Solidification Unit, like the solids control shale shaker, mud cleaner, desander, desilter, vacuum degasser, various decanter centrifuge, vertical cuttings dryer, high G drying shaker, various sizes and lengths screw conveyor, solids and sludge vacuum transfer pump, chemical dosing dewatering unit, oil sludge treatment system, thermal desorption unit, etc…

This week, a package of oil sludge treatment system was departed to an oil field service company in China. The unit will be used to recovery oil sludge from oil base drilling cuttings. The oil sludge treatment system including below items:
1) 2 phase decanter centrifuge. Material fed to 2 phase decanter centrifuge must be with solids content Less 20% and Particle Size less than 20mm.
2) 3 phase disc centrifuge. The solid phase material entering the three phase disc separator usually shall be reduced the solid content to less than 3% and the solid particles to less than 400 micrometers by the decanter centrifuge, then the three-phase disc separator can achieve the best effect.

3) Transfer pumps
4) Dewatering chemical dosing system with dosing pumps and automatic control system
5) Transfer tank and holding tanks for mud recovery and mud transfer.

The project is for processing oil and solid wastes in sludge storage tanks. After the oily sludge wastes have been pre-treated. After the oil sludge wastes have been treated by sieving, sand washing, demulsify, and finely screened, they have now achieved reductions and preliminary separation. After that, the oily sludge will be treated for three-phase separation.

Two phase decanter centrifuge and three phase disc centrifuge is used in the three phase separation process. After three phase centrifuge separation, the final outputs are soil, oil and water.

Chemical dosing system is used before 2 phase and 3 phase centrifuge separation to help for the removal of as more fine solids as possible.

Besides 2 phase decanter centrifuge, 3 phase disc centrifuge and chemical dosing sytem, GN Solids Control also offers other oil sludge treatment and transfer equipment, like 3 phase decanter centrifuge, high G drying shale shaker, mud cleaner, Vertical cuttings dryer, Drilling Cuttings Solidification Unit, Thermal Desorption Unit (TDU), oil water separator, sludge vacuum pump, screw conveyor, etc…

GN Solids Control 18 inch (450mm) diameter bowl decanter centrifuge is a big bowl centrifuge series. GN Solids Control 18 inch big bowl decanter centrifuge has 2 design options for different matrial separation request. The length over diameter ratio of GN 18 inch decanter centrifuge can be 3.4 : 1 or 4 : 1 for removal of low gravity solids from the liquid. And the big bowl centrifuge can reach a bigger capacity to reduce operating costs.

GN Solids Control 18 inch (450mm) diameter centrifuge is fitted with a 75hp main drive and a 30hp back-drive at one end for compact design. Depends on client’s selection The unit is optional to be fitted with main bearing temperature and vibration sensors. The optional sensors and functions give the GN 18 Inch Centrifuge improved standard on safety and performance monitoring features.

GNLW454EY is big bowl decanter centrifuge specially designed for waste water treatment. GNLW453 is also a big bowl decanter centrifuge. But unlike GNLW453 big bowl series decanter centrifuge, GNLW454EY is with a longer length and diameter ration to cater for waste water treatment requirements. And there are some other difference on the impeller and bowl design.

This week, 5 sets GNLW454EY big and long bowl Decanter Centrifuge was dispatched Tianjin sea port for departure to destination. T5 sets GNLW454EY big and long bowl Decanter Centrifuge will be used at a power plant to treat the waste water. The clients visited many centrifuge factories in China, and finally, they decided to buy from GN Solids Control. After months waiting, the 5 sets waste water treatment centrifuge is sailing for the client. Once the centrifuge arriving jobsite, GN Solids Control will send engineer to help for the first time commissioning and to train the operators.

Besides different models 18 inch big bowl centrifuge, GN Solids Control also makes small centrifuge from 9 inch, normal size 14inch, and bigger size 22inch and up to 30 inch bowl decanter centrifuge.

GN Solids Control makes Mud Recycling System and desanding plants for construction Trenchless Engineering Companies, like for HDD (horizontal directional drilling), TBM (Tunnel Boring Machine), Microtunnelling, piling, etc…

GN Solids Control has more than 10 years of experience in the design and manufacture of mud recovery systems, especially in trenchless projects with multi-function and compact design to cater for different demands and applications from clients. According to the different requirements from users, and jobsite situations, GN Solid Control can provides different configurations of mud recovery system and desanding plant to meet the requirements of different working conditions. There are usually two types of mud purification systems suitable for trenchless construction: one is sand removal unit with cyclone purification system, we usually call it desanding plant. And the other type of design is self-contained mud recovery system.

The desanding plant with hydro cyclone purification system occupies a small footprint, and is economical and affordable. The system is composed of a hydrocyclone and a double deck shale shaker, both of which are installed on a small mud tank. The sand removal cyclone purification system is a two-stage separation device, and its function is to remove coarse particles from drilling mud. The desanding plant is mainly used in projects that can accept larger particle size solid drilling mud, such as Microtunnelling, piling, and so on.

The high standard self-contained mud recovery system developed by GN Solid Control is composed of four stage separations: shale shaker for coarse cuttings separation, 10 inch desander cone separation, 4 inch desilter cone separation, and decanter centrifuge for ultra-fine solid separation. The mud tank of the self-contained mud recovery system has a bigger storage volume to store the purified drilling mud. At the same time, it also has more tank surface space to arrange more separation equipment. Customer can also choose a centrifuge to reduce the ultra-fine solid in the drilling mud and to avoid the enrichment of the ultra-fine solid phase in the drilling mud.

GN Solid Control not only has a standard sizes of mud recycling system and desanding plant, but also provides custom-designed mud recovery system to meet for different demands.

Recently, GN Solid Control has completed the design and manufacture of a set of oil sludge treatment system for an oil field environmental protection company in China. Since the oil sludge treatment system was launched on the market, it has been widely concerned by customers no matter in China or outside of China, and the feedback from the on-site operation of the market is good. More and more oil field environmental protection contractors inquire and order the system as an important solution to reduce the content of harmful substances in oil sludge efficiently and economically.

The oil sludge treatment system has two separation principles: chemical dosing and physical separation after heating. GN oil sludge separation system is composed of several modules with different functions to gradually recover water and oil from the sludge. The following is a brief introduction of the system:

1) Sludge vacuum transfer pump module – the sludge from oil-based mud drilling cuttings has high viscosity and high sludge content, which requires a powerful and efficient conveying device to suck the sludge out of the mud pit and feed to the oil sludge treatment system. GN sludge vacuum pump is a fully pneumatic pump with no electrical components and does not produce any sparks in use. it is especially suitable for oil and gas explosion-proof environment. With 85Kpa vacuum, the viscous sludge can be sucked and discharged to other place far away.

2) Pre-mixing module – before the sludge is fed into the separation module, the material needs to be homogeneously mixed to more than 80% of the liquid content. At the same time, in order to enhance the separation effect of oil and mud, it is necessary to add chemicals in the process of homogeneous mixing.

3) Separation module – GN Solid Control uses different separation equipment to separate oil and water from the sludge step by step. High G force shale shaker, 2-phase decanter centrifuge and 3-phase disc centrifuge are used in the Separation module.