GN screw press sludge dewatering machine is a kind of economical and environmentally friendly sludge dewatering equipment. It is a new type of sludge extrusion dewatering equipment using the principle of screw extrusion, through the strong compression force generated by the change of diameter and pitch of the screw, and the small gap between the floating ring and the fixed ring, to perform solids -liquid separation. GN dewatering screw press is composed of the fully automatic control cabinet, flocculation modulation box, sludge thickening, and dewatering device, and liquid collecting tank. GN dewatering screw press has automatic control technology, which can realize fully automatic flocculation operation and continuously complete sludge thickening and squeezing, finally return or discharge collected filtrate.


  • Suitable for a wide range of sludge dewatering and can be used for oily sludge treatment
  • It works continuously and automatically, it is not easy to be blocked.
  • Low investment and operation cost, without secondary pollution.
  • Compact design that saves energy and is environmentally friendly and takes up little space.
  • Sludge can be dewatered under aerobic conditions to avoid the release of phosphorous from anaerobic sludge dewatering.




  1. The main body of the screw press sludge dewatering machine is a filtration device composed of a fixed ring and a movable ring, in which the screw axis passes. The front section is for concentration and the rear section for dehydration.
  2. The filtrate gap formed between the fixed ring and the moving ring of the dewatering screw press and the pitch of the screw shaft gradually decreased from the concentrating section to the dewatering section.
  3. The rotation of the screw press shaft not only pushes the sludge from the concentration section to the dewatering section but also continuously drives the moving ring to clean the filter space and prevent clogging.
  4. After gravity concentration in the concentration section, the sludge is transported to the dewatering section. In the process of advancing, with the gradual decrease of the filtrate space and the pitch of the screw, and the locking effect of the backpressure plate, a large internal pressure is generated; leader, the volume is constantly reduced, in order to achieve the purpose of complete dehydration.
  5. The dewatering screw press is generally applicable to 2000mg/L-50000mg/L sludge concentration

GN dewatering decanter centrifuge is T series decanter centrifuge with a beach angle of 8.5 Degrees. GN T series decanter centrifuge is usually used for dewatering and thickening purposes. It is widely used for maximum dewatering requirements of municipal and industrial wastewater sludge. The dewatering decanter centrifuge is designed for easy separation of material including large particle size, the high-density difference between solid and liquid, low viscosity, high concentration, high treatment capacity, and higher dryness than clarity. The materials like sludge or wastewater containing fine particles usually need to be added with flocculants to gather the fine particles condensed into large ones, and then dewatered with T series decanter centrifuge.

Drilling mud, environmental protection sewage, oily sludge, cutting fluid, sand washing water, mineral washing water, soda white mud, salt mud dewatering, magnesium aluminum emulsion, steel-making wastewater, precision casting wastewater, construction mud, tunnel mud, mine wastewater, industrial wastewater, organic wastewater, aquaculture wastewater, chemical industrial wastewater, printing and dyeing wastewater, municipal sewage, river sludge, water plant sludge, lake sludge, kaolin grading, calcium carbonate, bentonite, Silica, titanium dioxide, calcium sulfate, barium sulfate, conductive film glass polishing solution, aluminum hydroxide, cryolite, silicate, oil sand separation, landing oil, oil sludge, coal tar, inorganic fertilizer, Chinese medicine extraction such as honeysuckle and licorice, clarification, concentration and dehydration of salt crystals, etc.


The beach angle of the T Series dewatering centrifuge is 8.5 Degree, which makes the decanter centrifuge cone section longer, that is, the drying and dewatering area of the centrifuge is longer, which is conductive to the dewatering performance of the T Series decanter centrifuge, and much drier solid materials discharged.
The shaft caps on the two ends and the bowl are made of duplex stainless steel SUS2205 or SUS2304 by centrifugal casting, which is superior to the performance of SUS304 and SUS316. The main parts are made by centrifugal casting and die forging process to avoid intergranular corrosion and incomplete residual stress release caused by the traditional welding process.
The screw blade is pressed by the CNC spiral blade forming equipment. Compared with the traditional drawing screw blade, it has higher slag conveying efficiency than the traditional drawing screw blade.
According to the material properties, the screw blade can adopt a gradual change type, which can obviously improve the efficiency of the screw’s transport and press force to make the solids dryer.
Optimized beach angle and pitch, large beach angle, and medium pitch with BD baffle plate make the dewatering zone separated from the sedimentation zone. The depth of the liquid pool is deeper and the dewatering zone is longer. The separated clear liquid is more clear and drier, and the processing capacity is larger. The deep liquid pool loses less kinetic energy when the clear liquid is discharged. The machine consumes less energy and is more energy-efficient At the same time, it has a material acceleration structure to reduce turbulence in the bowl to make the liquid clear, reduced turbulence makes the screw flight discharge port better protected for anti-abrasion, so the screw conveyor has a longer service life.

For special high-concentration and high-viscosity materials, a double cone design can be used, that is, the cone drum has two beach angles. The double beach angle greatly improves the resistance of slag discharge and increases the treatment capacity under the condition of increasing the slag dryness and liquid clarity.
The wear-resistant sleeve of the solid discharge port is a special hard tungsten carbide sleeve, of which the wear resistance is extremely high, and not fragile.
The overflow weir plate has a convenient and flexible design for adjusting the depth of the liquid pool to meet the requirements of dryness and wetness and clarity of materials under various working conditions.
The collection box cover of the small model is assisted to open by a gas spring, and it can support and protect safety.
The large model adopts a labor-saving lid opening device, and a single person can lift the lid of the collection box, reducing the labor intensity of workers and facilitating equipment maintenance.
Each type of the main bearing is designed with a hydraulic disassembly structure, which reduces the tension required to remove the main bearing by 90%, and reduces the risk of damage to the bearing itself and the high precision parts when the bearing is removed.
After each main rotary part is machined by high precision CNC equipment, the centrifuge is treated with three dynamic balance processing again, including the 1800RPM medium speed dynamic balance in the main rotary body component, the actual working speed high-speed dynamic balance, and the whole machine balance, so as to ensure the stable operation of the centrifuge under the high-speed working condition.
The screw propeller is protected by a replaceable wear-resistant alloy plate with long service life and easy maintenance.
Some models adopt the open-type screw blade, greatly enhancing the centrifuge processing capacity. Screw propeller utilizes stainless steel, after high-temperature solution treatment, not easy to deform, has good corrosion resistance, good strength stiffness, and long service life.
Two motors are arranged at one end of the centrifuge saving much space; the structure is compact for the operation and maintenance of the centrifuge while avoiding the accident of the motor damage caused by the material leakage at the inlet end.
The main bearing adopts premium SKF series high-end bearings with long service life. Depending on the user’s choice, it can also be equipped with an automatic lubrication system.
The grease lubrication system for the main bearing of the small model can be equipped with a semi-automatic or fully-automatic batch grease lubrication system, which can provide full and reliable lubrication for the main bearing, reduce the labor intensity of the workers and improve the service life of the bearing.
The main bearing of the large machine adopts the oil injection automatic circulation lubrication system, which has the function of cleaning and cooling the main bearing, and the service life of the main bearing is greatly improved.
With complete machine monitoring and alarm system. When overload, short

GN Solids Control is a leading manufacturer of decanter centrifuges. And our supplier from Switzerland is the leading brand in centrifugal hydraulic driving systems. GN and our Swiss supplier have been working together to develop the full hydraulic drive centrifuge for international customers to meet the highest standards.

The hydraulic bowl and displacement drive system drive both the conveyor and the bowl of a decanter centrifuge from the hydraulic pump unit via two hydraulic oil circuits.

The advantage of the fully hydraulic drive centrifuge is its use in high-temperature environments for heavy sludge with a flexible bowl and differential speed. The compact single skid design makes mounting easy.

Model GNLW363D-FHD

  • Bowl size 360×1270 mm
  • Bowl speed 0-3400 RPM (2328G)
  • Differential speed 0-70 RPM
  • Motor power 45 KW
  • Swiss drive system Hydraulic drive
  • Maximum capacity 200GPM (45m3/h)
  • Maximum torque 4163 N.M
  • Dimension (mm) 3000x2400x1860mm
  • Weight (KG) 3400KG



The fully hydraulic system consists of A the hydraulic pump unit, B the bowl drive hydraulic motor and C the travel drive.

Hydraulic pump unit A feeds hydraulic oil to scroll drive C and bowl drive B by two separate and individually independent operating circuits

An electric motor A1 drives the combined pumps A2 and A3. Each operating circuit is equipped with its own hydraulic pump and controls. The pump unit contains all adjustment devices and safety valves as well as pressure gauges.

With this system, the rotation speed of the bowl, as well as the differential speed of the scroll, can be manually adjusted independently of each other, continuously and infinitely variable during the operation of the centrifuge.

GN designs and manufactures a hydro-vac sludge processing system. It is also called hydro-vac sludge waste treatment or sewage sludge management system. The sludge processing solution is to use liquid and solids separation equipment to treat the soil, soup, or sludge generated by the Hydrovac or HDD project and produce reusable material for construction and clean water discharge. Normally, the slurry is free of contaminants and comes from the physical location of utilities in the public right-of-way and from directional drilling for laying underground pipes or utilities or other privately owned construction.

Features of the GN Hydrovac sludge processing equipment

  • Full package design for turnkey solutions
  • Many years of experience in the field have shown
  • 5-phase separation system for a better result
  • Modular system for quick installation and flexible movement.


Main equipment for GN Hydrovac sludge processing system

Feed Hopper Feed Hopper for Hydrovac Truck Slurry Loading

Coarse Vibration Screen For separation of coarse material from Hydrovac slurry

Fine agitator module For processing fine solids from hydro-vac sludge residues

Desilter unit For sediment separation with an underflow dewatering screen

Hydrovac dewatering decanter centrifuge For removal of ultrafine solids from sludge tailings


Polymer dosing system To mix and supply polymer to the dewatering centrifuge

chemical products


Hydrovac Excavation Introduction:

Hydrovac excavation is a non-destructive, precise, non-mechanical process that uses pressurized water and an industrial-strength vacuum to simultaneously excavate and evacuate soil. As the pressurized water breaks up the soil, it creates laitance that is removed using a powerful vacuum in a waste tank. Hydrovac is currently the only non-destructive process method for the excavation operation. Hydrovac excavation can efficiently and accurately excavate in a variety of soil types and environmental conditions, including frozen ground conditions, clay, hard-packed earth, and in remote areas or locations with limited access. Residual slurry from the Hydrovac excavation will be sent to the Hydrovac slurry processing plant for treatment to recycle the water and construction material.

What type of material can the GN Hydrovac sludge processing system handle?

  • Soil / Soup / Mud (mud) generated from hydro-vac excavation
  • Horizontal directional drilling mud
  • Shield tunneling machine for sludge
  • Mud treatment of bored piles.
  • Other construction sludge waste


GN Polyurethane Screen Panel is commonly used in the dewatering and classification of mineral process and construction industries. GN polyurethane screen panel is manufactured by the processing technology of steel wire covered with polyurethane. It is characterized by firm structure and durability. GN polyurethane screen panel adopts high-quality polyurethane raw materials, which have excellent elasticity, super wear resistance, and good screening efficiency. All polyurethane raw materials and their proportion have been tested and strictly selected, and advanced injection molding technology and precision designed & manufactured molds are used for injection molding, which can guarantee GN polyurethane screen panels are completely customized according to your needs. Opening shape and opening size, screen plate thickness, fixing method, overall size, and other elements can be arbitrarily determined. GN polyurethane screen panel can also realize various surface shapes on the screen plate: retaining dam, anti-smashing strip, guide strip, and guide block to improve the screening efficiency.



Polyurethane screen panel has a long service life: Generally, more than 6 months, up to one year. Its service life is 8 ~ 10 times longer than the traditional metal screens, 3 times longer than SS screens, and 3.9 times longer than natural rubber.

The production material of polyurethane screen panels belongs to polymer organic elastomer, which has good wear resistance, flexing resistance, and large loading capacity.

High screening rate, self-cleaning screen surface, anti-plugging.

Polyurethane elastic screen panel uses steel wire or metal frame as the skeleton material, which can improve the bending flexibility and increase the loading capacity.

The cone angle of the screen hole is greater than 140 °, and the water permeability of polyurethane is strong, which can effectively prevent the adhesion of wet fine particles, so it is suitable for the screening and separation of wet fine materials.

The use of metal mold can ensure accurate screen opening, high opening rate, and high screening efficiency.

Multiple choices of hole types: Rectangle, square, circle, and other.

Wide application range and strong industrial applicability: the screening of various materials within the range of 0.1mm-170mm, whether dry or wet, will not affect the screening rate. The advantages of polyurethane screen panel are more fully displayed for dehydration and demineralization screen in the range of 0.5m-3mm

Good moisture resistance. It can be used in water or oil and water medium, which can improve the service efficiency and service life

Adopt the modular installation method (300 * 600mm), which significantly reduces the use cost, is convenient for replacement and installation, and reduces the work intensity of replacement

The various product line, GN polyurethane screen panel can match global well-known brand screening machines.

Low noise. No matter what substances and materials are screened during use, there will be no great noise, reducing the noise level by up to 9 dB. This is a 50% reduction in noise perceived by the human ear.

The polyurethane screen panel is not easy to rust, and the storage life is greatly extended. It can be stored for more than 5 years without affecting the service life.

Whether your screening process is used for dewatering, raw ore classification, desliming, or demineralization, GN’s professional knowledge and experience in customized screening systems can ensure to provide the best solution. GN Polyurethane Screen Panel provides customized solutions for your specific screening needs to ensure the screening effect while achieving less wear and longer service life.