3 phase disc centrifuge and 3 phase decanter centrifuge is 2 equipments normally used for oily water separation, both of them have their advantages and disadvantages.
The comparison is as below:
Both of the 3 phase disc centrifuge and 3 phase centrifuge are for light liquid, heavy liquid, and solids separation, just one is vertical centrifuge, the other one is horizontal centrifuge.
The working principal is different:

3 phase Disc centrifuge: the oily water is feed into the disc centrifuge, under the centrifugal force, the material pass through the disc bundle separation intervals, the light liquid and heavy liquid are discharged by the lower centrifugal pump and the upper centrifugal pump respectively, the solids is discharged regularly.
3 phase decanter centrifuge: when the oil sludge is feed to the centrifuge inlet pipe and enter into high speed bowl, the material rotates synchronously with the bowl.The centrifugal force became less from outside to inside. The solids are pushed by the screw conveyor, the water is discharged from the nozzle in the upper, the oil is discharged from the bottom nozzle .

The disc centrifuge can be applied for materials with fine solids and with less solids content, so the material to be feed to disc centrifuge is very strict limited, the solids content should be less than 3% and the particle size is no more than 1mm, so normally we will use a decanter centrifuge before the disc centrifuge, to reduce the solids content and separate the big solids from the oily water/ oil sludge. So the cost of the proposal with a decanter centrifuge and a disc centrifuge will be definitely higher than 3 phase decanter centrifuge, but the treatment result will be always better, it can meet the requirement for oil recovery, solids disposal safely and water to be sent to waste water treatment.

As a waste sludge dewatering equipments manufacturer in China, GN solids control can produce a range of sludge dewatering equipments for our clients applied for different industries. Such as dewatering centrifuge, screw press dewatering machine, chemical doing unit. Recently one batch of waste sludge treatment equipments are ready for shipment to our environmental company customer.

Dewatering centrifuge unit with chemical doing unit is the most popular dewatering equipments for waste sludge treatment, like oil sludge treatment, construction waste sludge treatment, industrial waste sludge treatment. It is consist of one unit of dewatering centrifuge with VFD control panel, one unit of centrifuge feeding pump, one set of fluids collection tank, one unit of chemical dosing unit, sometimes it is installed on the skid of mud tank, sometimes it is in a separate skid or installed inside a 20ft container for sun/water proof and convenient operation. The waste sludge and prepared chemicals are mixed inside the centrifuge feed pipe, sometimes we will install Static mixer before that for their better mixing, then the mixture sludge will flow to centrifuge and treated as solids and liquid. If the user need further treatment like fluids with fluids, such as oil and water, we will use 3 phase decanter centrifuge or 3 phase disc centrifuge to treat the fluids to get pure oil and relatively pure water.

The screw press machine is introduced as sludge extrusion dewatering equipment, compared with filter press and dewatering centrifuge, it has its own advantages and disadvantages. For energy saving, decanter centrifuge is the highest engery consumption, ,and screw press is the lowest, for cost issue, filter press is the highest, decanter centrifuge in middle and screw press is the cheapest. For treating capacity, decanter centrifuge is high with better treatment result, the screw press is lower, for operation cost, screw press is the lowest.

As a HDD mud reclaimer manufacturer in China, GN solids control can design and produce the solids-liquid separation solution for HDD, CBM, TBM, Piling, etc works. Recently we shipped one batch of mud reclaimer eqiupments to our HDD company client, including:

2 units of GNMS-500D desander unit: this is an economic configuration mud recycling unit, with 1 unit of double deck shale shaker plus desander cone, 1 unit of centrifugal pump as desander feeding pump, 1 unit of fluids catching tank to collect the discharged fluids from coarse solids separation screen layer in the bottom, the centrifugal pump suck the mud from this catching tank to desander cone, the separation cut point is 45 microns, the clean fluids from desander cone will flow to mud mixing tank through pipelines, and the solids will drop on the top layer screen of the dual deck shale shaker for drying and recycling.

1 unit of mud mixing tank, the tank capacity and mixing capacity can be customized according to your requirement, we can add one or 2 mixing hopper with 1 or 2 mixing pump to meet your requirement from 200gpm mixing unit to 1400gpm mud mixing capacity. For this project, we make 2 units of venturi hopper with 2 units of mixing pump installed on the skid of one side.

1 unit of double deck shale shaker, normally it is used to separate the coarse solids from the drilling fluids, with 2ea of 2.5HP vibration motor produced high G force, the total screen area is up to 4.63m2, it increase the treating capacity compared with single deck shale shaker and it can treat the mud much cleaner. Both of the top layer shaker screen and bottom layer shaker screen are made of composite material frame shaker screen to ensure the separation performance.

Recently one set of oil based drilling waste management system are ready for shipment to our client in China. The technical configuration is as below:
（1）1 set of GNCD930F vertical cuttings dryer with telescopic skid, with 900rpm speed and max G force is up to 420G
(2) 1 set of GNLW363C-VFD decanter centrifuge installed on the fluids catching tank, and screw pump as feeding pump
(3) skid assy and mud tank, the

The working process is as below:
When the drilling waste management system is installed on the rig site, the drilling cuttings will be collected by screw conveyor directly and automatically transfer to the vertical cuttings dryer for treatment. When the drilling waste management system is installed in the waste facility, probably they will use forklift with a hopper to receive the waste and dump into the collection hopper, which is connected with a screw conveyor inlet port, the drilling waste will be transferred to vertical cutting dryer feeding port automatically through its discharge port; Another way is that the client use the excavator to pick up the drilling waste and sent to the collection hopper, the collection hopper should be big enough to receive the oil based drilling cuttings.

When the drilling waste is water based drilling cuttings or mixture of oil based mud and water based mud, they can not use this system to treat the drilling cuttings. For water based mud drilling waste treatment, we normally user high G drying shaker to separate the big solids firstly, and the fluids are treat by dewatering centrifuge with chemical dosing system. For mixture drilling waste which is collected from offshore drilling rig, they can not be separately collected, we will suggest oil sludge separation unit, we have 1~2 m3/h, 5m3/h, 15 m3/h oil sludge treatment unit for option.

The three phase decanter centrifuge can be used for oil tank bottom cleaning sludge treatment, relatively, we can use 1 unit of 2 phase decanter centrifuge with 1 unit of disc separator to instead of it. How to select it?

3 phase decanter centrifuge, the cost is cheaper compared with using 1 unit of decanter centrifuge plus 1 unit of disc separator. But for the treatment result , 1 unit of decanter centrifuge + 1 unit of disc centrifuge is better, also the application range is also much wide than 3 phase decanter centrifuge.
To ensure the separation process of 3 phase decanter centrifuge, the user should confirm that the solids content is less than 10%, and the oil content is higher than 10%, otherwise the separation result will not be good, as the high content solids will block the screw easily, and the less oil will lead the liquid – liquid separation very difficult.

The 2 phase decanter centrifuge can separate the solids with liquid efficiently by using with chemical dosing unit, the prepared chemicals are feed to decanter centrifuge , at the same time, the decanter centrifuge feeding pump also feed the sludge to decanter centrifuge, they mixed well in the feed tube , so that the suspend solids will be accumulated well and will be easily separated out of the fluids, only left very few fine solids( less than 3%) and the solids size is very small, then it will be feed to disc separator, for oil and water separation.
We have 3 models of 3 phase tricanter for option, GNSX-350 with designed capacity 5m3/h, the lubrication method is by grease, GNSX-450 with designed capacity 10m3/h, GNSX-520 with designed capacity 15 m3/h, which the lubrication method is by oil pump. For more information, pls contact with GN solids control.

As the screw conveyor and screw pump manufacturer in China, GN solids control recently shipped one batch of screw conveyors and screw pumps to our client in Africa. These equipments are used for drilling waste management system, the screw conveyor is used to transfer the drilling waste to vertical cuttings dryer, the screw pump is used to feed the decanter centrifuge and flush the vertical cuttings dryer.

A drilling waste management system including a vertical cuttings dryer with flushing pump, a decanter centrifuge with its feeding screw pump, telescopic skid, fluids collection tank, screw conveyor for drilling cuttings transfer, for discharged solids collection and transfer. As the important components of the drilling waste treatment system, the screw pump and screw conveyor’s quality is very important. The client already bought GN decanter centrifuge and vertical cuttings dryer before.

The screw conveyor system is customized according to the site layout, the screw diameter is optional for 10 inch, 12 inch, 14 inch, 16 inch, 18 inch, the screw length for each section is 12ft, the client can select 1 section (12ft ), 2 section (24 ft) , 3 section (36 ft), 4 section ( 48 ft), the screw conveyor can be installed horizontally or slantly ( the installation angle should be less than 45 degree). The inlet port and outlet port can be customized according to their requirement. the manual adjustable speed ensure the feeding rate can be controlled manually, the user can adjust the feeding rate according to vertical cuttings dryer working conditions.
The screw pump fluids touch components are made of wear resistant alloy, the manually adjusted speed can control the feeding capacity to the decanter centrifuge, once the solids content is higher, the user can reduce the feeding to avoid blocking the screw.
If you need screw conveyor and screw pump, pls contact with GN Solids Control.

As a VFD decanter centrifuge and vertical cuttings dryer manufacturer in China, GN solids control recently shipped another batch drilling waste management equipments to Nigeria again. This is not the first order, they repeat purchasing VFD decanter centrifuge and vertical cuttings dryer from GN solids control. The technical configuration is as below:

1.    3 units of GNLW363C-VFD decanter centrifuge,
2.    2 sets of GNCD930F vertical cuttings dryer, according to some of our client, the Oil content in the cuttings can be reduced to below 5%, it can meet some countries disposal regulation, so that they will use the discharged solids for landfill or construction industry.

3.    Telescopic skid and feeding pump, the feeding pump is installed on the telescopic skid, during transportation, the decanter centrifuge and vertical cuttings dryer will be removed for separate shipment.
For rest accessories, such as connection pipeline, fluids catching tank, etc, the user can make it locally according to their layout. Different with GN standard drilling waste management system, which is a skid mounted drilling waste management system for convenient transportation, the separate part of decanter centrifuge module and vertical cuttings dryer module is more flexible, it can be used for different projects.

Except for VFD decanter centrifuge and vertical cuttings dryer, GN solids control also produce the drilling waste transfer system and we can provide customized waste transfer solution. Including screw conveyor, sludge vacuum pump, fluids collection hopper, etc. The screw conveyor is the most common used equipment for drilling waste transfer. It is consist of explosion proof motor, gearbox, coupling, shield, bearing sear assy of driving end, header of driving end, housing, screw shaft, middle bearing seat assy, blind flange, connection plate of the blind flange, inlet, bearing seat assy of the feeding end, header of the feeding end, gland, outlet and drive seat.

As one of solids transfer pump manufacturer in China, GN solids control produce different size of vacuum pumps to meet our customer’s requirement. The vacuum pump can be used as solids transfer pump, mud transfer pump, oil waste / oil sludge transfer pump, waste water transfer pump and other waste such as animal waste, etc.
We have 3 models vacuum pump for option, GNSP-10B, GNSP-20B, GNSP-40B.

The suction process is that the compressed air is sucked in the vacuum tank through the air intake, when the air fulfill the vacuum tank (body ), it produced a genitive pressure in the vacuum tank, which can suck the sludge/ water/ solids from outside to the vacuum tank through the suction port ( material). At the same time, the compressed air is discharged from air vent port . During suction ,air intake valve should be open, air vent valve should be closed. Suction valve should be open, and discharge valve should be closed. There is a timer setting inside the control panel, by which the user can set proper suction time and discharge time according to their experience and material conditions. There are 2 working mode for option, one is automatically operation, one is manual operation, the user can select as per their requirement. Under automatic mode, the vacuum pump will suck and discharge as per the setting time automatically.

The discharge process is that once suctiton process is finished as per the setting time, the suction valve is closed and discharge valve is open. The vacuum tank valve is closed as a close tank, the air enter into the pump body and push the sludge / fluids/ solids to discharge port, and the air flow out of the pump body.
If you need more information or working video reference of our vacuum pump , pls contact with GN solids control.

GNLW764A-VFD decanter centrifuge with dewatering unit are delivered to our TBM engineering client for TBM slurry separation, the big bowl big volume decanter centrifuge GNLW764A-VFD is the biggest model we can produce right now, the technical specification is as below:

Bowl diameter: 760mm, bowl length : 3328mm, the designed treating capacity is 528gpm, max bowl speed s 2650rpm, normally used 2200rpm, max G force is 3000G, the typical G force is 2060G,the gearbox torch is 25000N.m. with gearbox ratio 38:1, the differential speed adjustable from 5 to 28 rpm, the main motor power is 160KW, the back drive motor power is 90KW, the mechanical separation cut point is 2 ~ 5 microns.

To get more pure water and drier solids discharged, the user can add flocculants to the mud with chemical dosing unit GNDW-6000L, which with treating capacity 6000L/h. the chemicals can be added into the 3 compartment chemical mixing tank, which with mud agitator, to mix the dry powder with water, the mixed chemicals are feed to decanter centrifuge feed tube by the chemical dosing unit, we have 2 units in the system, one for use, one as back up. The mixed chemical are mixed with slurry in the decanter centrifuge feed tube and separated by the decanter centrifuge, the chemicals can improve the separation efficiency and get more clear water and much drier solids, the water can be reused by TBM, the solids can be colleted by bag or transported by truck. All the equipments are installed inside the 20ft container, 2 containers overlay placement can save space requirement, and for convenient transportation, also it is sun proof, rain proof and user friendly design, equipped with proper windows, doors, lightings and air conditioner.

If you need a customized TBM slurry separation solution, pls contact with GN solids control.

Recently one set of 3 phase separation skid are shipped to environmental solution company, the technical configuration is as below:
1.    One unit of GNLW554ET-VFD decanter centrifuge, with bowl diameter 22 inch, bowl length is 91 inch, the designed max capacity is 600gpm, for oil sludge treatment unit with adding proper chemicals, the capacity can be expected as 15m3/h. the max G force is up to 3051G, the separation cut point is 2 ~ 5 microns, with chemicals jetting, the separation cut point is up to 1 microns. The different speed adjustable range is 0 ~45 rpm, the max torque is 12000 N.M., with main motor 125HP and back drive motor 60HP.

2.    Screw pump 2 units, one is for decanter centrifuge feeding, the other one is for disc centrifuge flushing pump.
3.    Disc centrifuge GNSD-125, vertical centrifuge, 3 phase separation for oil water and solids separation
4.    2 sets of skid, one for decanter centrifuge, one for disc centrifuge, the treating capacity of the unit is 15m3/h for oil sludge.

The decanter centrifuge installed on the centrifuge skid with screw pump with VFD control panel.
The disc centrifuge is installed on the 3 phase separation skid with flushing pump, with flushing tank to avoid solids blocking.
We can make it as a complete skid for convenient transportation, also we can make it separately for flexible connection, the client can use them for different projects if required. If they need to lift it to the jobsite, we can also make the design compact footprint.
If there is coarse solids inside the oil sludge, coarse solids separation shaker modular should be used before the decanter centrifuge separation skid, if the oil sludge with less flowability, pre-mixing tank with heating lines should be used firstly to dilute the oil sludge, adding chemicals, mixing and heating before feed to coarse shaker modular and decanter centrifuge modular.