Comparation of GN Screw Press and Centrifuge in Dewatering.

In the field of solids control and waste management, particularly in industries like waste water treatment, the demand for effective dewatering solutions is crucial. Among the technologies that stand out in this domain are the GN Screw Press and the Decanter Centrifuge. Both play pivotal roles in separating liquids from solids, each employing distinct mechanisms tailored to different needs. Let’s delve into a comprehensive comparison of these two technologies to understand their strengths and applications.

GN’s Screw Press  stands as an effective dewatering solution crafted to clarify liquids across various industries. This innovative technology leverages screw extrusion, employing the robust squeezing force generated by the alteration of screw diameter and pitch, along with the minute gap between the floating ring and the fixed ring. 

A primary advantage of the GN Screw Press lies in its low energy consumption. Operating at a lower speed, typically around 2-5 RPM, it consumes less power compared to traditional centrifuges. This not only leads to cost savings but also positions it as a more environmentally friendly option. However, it’s important to note that its primary application is in water treatment projects, and its capacity is relatively less than a centrifuge of similar size.

GN Decanter Centrifuges , on the other hand, are longstanding and widely adopted technologies for dewatering applications. Operating on the principle of centrifugal force, the high-speed rotation of the drum or bowl effectively separates liquids and solids based on their densities.


Decanter Centrifuges are recognized for their rapid dewatering capabilities, ideal for applications where time is a critical factor. GN offers dewatering centrifuge models such as 224, 364, and 554, with a length-to-diameter (L/D) ratio of 1/4. In industries like oil drilling, where swift clarification of drilling fluids is essential, centrifuges excel in delivering rapid results with a L/D ratio of 1/3. Additionally, decanter centrifuges prove proficient in separating oil-based fluids.

However, the efficiency of centrifuges comes at a cost, both in terms of energy consumption and maintenance requirements. These machines typically have a higher energy consumption rate, requiring substantial motor power. Furthermore, the high-speed rotation can lead to increased wear and tear, necessitating higher maintenance for the bowl and conveyor components. And the recommended feed pump is GN screw pumps for low speed, and steady pressure supplying.

When deciding between the GN Screw Press and a Centrifuge, several factors should be considered. These include the nature of the material being processed (solids particles, density, etc.), the required level of dewatering, energy efficiency goals, and maintenance considerations.


It’s worth noting that if equipment needs to be placed outdoors, protective measures, such as sun and rain shields, are advisable for the Screw Press, whereas the Decanter Centrifuge can be exposed directly to the elements. For more details, please feel free to contact Sam via WhatsApp at +8618034263511.

Hydraulic Centrifuge and Screw Pump: A Match Made for Wastewater Treatment.

Hydraulic centrifuges and screw pumps are two types of equipment that are often used together in industrial applications. The hydraulic centrifuge is used to separate solids from liquids, while the screw pump is used as the feeding pump for the centrifuge.

GN Solids Control is a leading manufacturer of decanters centrifuges. We have partnered with Viscotherm and ROTODIFF®, leading brands of centrifuge hydraulic driving systems from Switzerland, to develop the Full Hydraulic Drive (FHD) Centrifuge. This centrifuge meets the highest standards and is designed for international clients. The FHD Centrifuge uses a hydraulic bowl and scroll drive system that is powered by a hydraulic pump unit. This system drives both the hydraulic motor ROTODIFF and the bowl of the centrifuge. The two hydraulic oil circuits allow for independent, stepless, and large-range speed regulation for the bowl and conveying. The FHD Centrifuge has several advantages. It can be used in high-temperature ambients, is designed for heavy mud, and has a flexible bowl and differential speed. The compact one-skid design makes it easy to rig up.

A screw pump is a progressive cavity pump that uses a rotating rotor with a series of helical blades to move fluids. The blades create a series of chambers that trap the fluid and move it along the pump. The pump is gentle on the fluid, so it does not shear or agitate it. It can handle high-viscosity fluids and hard-suspended particles for a mud system, and a good feeding pump for centrifuges. It is easy to maintain, better pumping than a centrifugal pump, and the only worn parts are the rotor and stator.

The combination of the centrifuge and the screw pump could be mounted with a skid:

If you are interested in the skid and equipment, or you have a project in drilling mud treatment or waste fluid treatment, please feel free to contact me for more details.

This week, I am Focusing GN Dewatering system in Soil Treatment.

The GN sludge dewatering system is applicable to bottom sludge cleaning projects in various fluids including water-based sludge.

The GN sludge dewatering system adopts the step-by-step treatment design principle. According to the particle size contained in the sludge, the solid phase is separated from the fluids through different separation equipment including the shaker and the centrifuge. The following is a brief introduction to the main equipment and operating principle of this system:

Shale shaker- High G GNZS594 and Vist GNZS594: In this system, the first stage separation equipment is a single GN shale shaker, which can effectively separate the coarse particles in the suspension through the screens with different mesh sizes, to reduce the load of subsequent separation. A Vist shaker uses a combination of vibration and vacuum to remove cuttings from the drilling fluid.

mud cleaner

Hydrocyclone units: The sludge treated by the shale shaker is sent to the mud cleaner, to separate particles with a size of approximately 75 microns and 20 microns from the fluids, respectively. The system is equipped with four sludge centrifugal pumps, which are used as feed pumps for the desander and desilter cyclones equipment installed on the shaker.



Decanter centrifuge: To obtain more clarified water, a sludge dewatering centrifuge must be used to separate the fine particles in the muddy water. The projects generally require a relatively large flow, so GN is equipped with the largest GNLW764A-VFD drainage centrifuge that can be produced. The diameter of the bowl of this centrifuge is 760mm. During operation, the maximum separation factor can reach 2650G. The solid phase of 2 ~ 5 microns can be separated, which makes the separated liquid phase clearer.

In addition to the separation equipment, GN is also equipped with sludge storage tanks for temporary storage and liquid reception in this system. At the same time, the solid slag from the discharge equipment is also equipped with screw conveyors to transport the slag to the outside of the system. The GN  sludge dewatering system is a high-efficiency and high-performance system that can help customers effectively clean the sludge of soil.