Recently GN solids control shipped one batch of screw conveyor and vertical cuttings dryer for international environmental Engineering company.


The screw conveyor is used to collect the drilling waste and transfer to vertical cuttings dryer, the discharged solids are also collected and transferred automatically to cuttings box. The vertical cuttings dryer are installed inside the container, with proper open on top for convenient maintenance and operation, and also open doors in proper place, the flushing pump of vertical G dryer and decanter centrifuge feeding pump are also installed inside the container to keep them working in warm temperature. The screw pump is from Netzsch brand single screw pump with explosion proof motor. The fluids treated by vertical centrifuge flow to storage tank, the decanter centrifuge feeding pump transferred the fluids to decanter centrifuge to separate more fine solids.


The screw conveyor is U type screw conveyor with rotating screw to move the material along the fixed casing continuously. We can make feed port and discharge port at any position in the length direction as per client’s requirement. Not only for drilling waste, the screw conveyor can be also used to in different industries, as food, medicine, chemicals, paper making, environmental solutions, construction industry and other industrial applications. To select a proper model screw conveyor, we need to know the required transfer capacity and power required and transfer length. We have 10 inch, 12 inch, 14 inch, 16 inch, 18 inch screw diameter for option, and divided each section as 12ft, we have 12ft, 24ft, 36ft and 48ft for option.


For GN screw conveyor: the screw flights are made of wear resistant and thicker manganese steel, and it is aso sprayed with wear resistant coating to prolong its working life. The bearing seats are made of aluminum casting for reliable performance.

The main equipment to be used for OBM waste treatment is vertical cutting dryer and decanter centrifuge, depends on different countries environmental regulation, the oil content required for drilling cuttings disposal is different, normally below 5% is acceptable for developing countries, below 1% is acceptable for developed countries. GN vertical cuttings dryer treatment result for the discharged solids is OOC 3% to 5%.We also have standard design for drilling cuttings dryer system as a compact package for convenient transportation and operation.


There are different ways of feeding system to vertical cuttings dryer, including vacuum pump, drilling cuttings transfer pump, screw conveyor system.
Vacuum pump is 100% air operated pump, it can be widely used for electricity power supply area, and the space requirement is very small. It is the ideal equipment to transfer drilling cuttings, sand, cement, drilling fluids, waste water, oil sludge, animal waste, etc. materials, and the suction distance is up to 50m and discharge distance is max 1000m, especially for the high solids content material.


Drilling cuttings transfer pump is drived by hydraulic cylinder and S-style distribution valve, it can be used to transfer high solids concentration material, less moisture, big solids size and high abrasion material.
Screw conveyor system is traditional drilling cuttings transfer way, normally one set of screw conveyor picked the drilling cuttings from shale shaker, desander, desilter horizontally, one set of screw conveyor is installed slantly to pick up the drilling cuttings from #1 screw conveyor and transfer to vertical cuttings dryer. The installation space is larger than vacuum pump and cuttings transfer pump.
The vertical cuttings dryer discharged fluids flow to intermediate tank and the centrifuge feeding pump feed the fluids to decanter centrifuge to separate fine solids, the mechanical separation cut point is 2~5 microns. The treated fluids can be recovery to solids control system to prepare for new drilling fluids.

Recently GN solids control shipped 2 sets of containerized vertical cuttings dryer system for OBM treatment to Russia. This is the repeat order from the Russia client, the technical specification is as below:
1) One unit of vertical cuttings dryer GNCD930E to treat oil based drilling cuttings


2) One unit of mud tank to storage the fluids discharged from vertical cuttings dryer, the mud agitator is installed on top of the mud tank.
3) One unit of 40ft standard container with proper window and doors, the handrails, stairs are equipped properly to meet HSE requirement. The bottom opening is for discharge of solids from vertical cuttings dryer discharge port, it will be collected by screw conveyor and transferred automatically to cuttings box. There is insulation materials inside the container inner wall to keep the equipments warm for continuous working in winter, when the environmental temperature is below -5 degree.


4) All of the electric motor and control panel are explosion proof for zone 1 and zone 2. We can also provide IEC EX and ATEX, UL certified explosion proof motor and control system for special requirement.
The decanter centrifuge can be also installed inside the 40ft container on top of the support frame, the container top can be opened for maintenance and parts replacement. The VFD decanter centrifuge is used to treat the discharged fluids from vertical cuttings dryer, to separate more fine solids from the fluids, the recycled water can be reused to prepare for new fluids. The VFD control panel can adjust the bowl speed, differential speed and pump speed to adjust the feed flow rate.
The vertical cuttings dryer is the ideal equipment to treat the oil based mud drilling waste management, the separated solids with oil content in the cuttings is below 5%, which is allowed for landfill in some countries.

Recently one unit of mud cleaning system for offshore platform is ready for shipment. Different with normal design drilling mud cleaning system for onshore drilling, the mud cleaning system for offshore is with different features, like compact design, convenient transportation, offshore lifting frame, explosion proof standard to meet offshore drilling requirement, painting and coating to meet offshore requirement for better corrosion resistance.


The technical configuration is as below:
1) One unit of linear motion shale shaker, the discharged solids are collected by buffer box and collected by screw conveyor, which can transfer the drilling waste to cuttings box. The shale shaker are installed on the mud tank with offshore standard lifting pad, it needs to be lifted to the offshore platform frequently, the safety should be assured. All the mud tank pipelines are layout outside for convenient maintenance and operation. All the valves, fittings, flanges are all oil resistance material for longer working life. The shale shaker equipped with 2 ea Italy Oil brand vibration motor, the shaker screens are produced comply with API RP13C standard, with 3 layers stainless steel material wire mesh, composite material frame for longer working life. The shaker screens fixing method is by wedges.


2) One unit of mud cleaner (desander, desilter and shale shaker 3 in 1), the desander cone and desilter cone are all made of 100% polyurethane material for longer working life. The bottom shale shaker is same model with the shale shaker, the shaker screens are with same dimension. The shaker deck bottom are made of stainless steel material for better corrosion resistance.
3) Centrifugal pump, the pump casing and impeller such wear parts are made of ductile hard alloy for longer working life, FAG brand bearing for reliable operation. We can get offshore lifting pad certificate as per client’s requirement.

GN decanter centrifuge has worked successfully for power plant waste water treatment in Taiwan, China. The project configuration is as below:
1) Total equipments: 5 sets of GNLW454E decanter centrifuge


2) Material to be treated: power plant waste water
3) Target: Discharge sludge with water content below 75%.
4) Main concern: the solids content is very low, and much ultra fine solids, and the waste water is highly corrosive chemical water.


GNLW454E decanter centrifuge is special designed for waste water treatment, according to the samples we received from the customer, we had designed special bowl angle, pond depth, and bowl major materials for better corrosion resistance for the chemical waste water, normally our standard bowl material is duplex stainless steel 2205 or 2304, for this project, we use duplex stainless steel 2507 for better corrosion resistance.The basic technical specification is as below:
Bowl diameter: 450mm (18 inch), bowl length 1890mm (74.5 inch), the length/diameter ratio is 4.2, the max bowl speed is 4000rpm with max G force 4032G, the main motor is 45KW, the back drive motor is 11KW.
Below is the photo to show the discharged solids from our decanter centrifuge, the customer is satisfied with the treatment result.
Below is the photo to show the feed in waste water and after treatment clean water.


For the 18 inch bowl decanter centrifuge, we also have other models for different applications, such as GNLW453C-VFD can be used for oil & gas drilling solids control system and drilling waste management system, it can be also used as dewatering centrifuge with chemical dosing system. GNLW452D decanter centrifuge is middle speed decanter centrifuge, it can be used for barite recovery in the solids control system, it can be also used for construction tailing slurry treatment.
If you need a decanter centrifuge solution, pls contact with GN solids control.