Jun 04

       The decanter centrifuges made in China are different from the imported ones. The imported decanter centrifuge with the same function is about 6 to 10 times cost than the domestic one.

 The reason is that the imported decanter centrifuge is durable, and the control of temperature and speed is more accurate. The price difference between centrifuges of the same grade is not very big, mainly distinguished in performance and configuration. The difference of the equipment is that in terms of performance, centrifuges with freezing are much more expensive than ordinary ones. Some centrifuges also have heating functions. The more control programs, the higher the price of the centrifuge. The big difference is the configuration. Sometimes the price of accessories is higher than the price of the equipment. When purchasing, please note that in addition to the equipment, the selected rotor (number and type), plus the necessary centrifuge tubes, tube sleeves, special centrifuge bottles or blood bags, all of which add up to a complete centrifuge price. Centrifugation is to use the strong centrifugal force generated by the high-speed rotation of the centrifuge rotor to accelerate the sedimentation speed of particles in the liquid, and separate the substances with different sedimentation coefficients and buoyancy density in the sample. Therefore, it is necessary to use a centrifuge to generate a strong centrifugal force in order to force these particles to overcome the diffusion and generate a settling motion.


A decanter centrifuge is a machine that uses centrifugal force to separate components in liquid and solid particles or a mixture of liquid and liquid. The centrifuge is mainly used to separate the solid particles in the suspension from the liquid; or to separate two liquids with different densities in the emulsion that are incompatible with each other (such as separating cream from milk); it can also be used to exclude Liquid in wet solids, for example, dry clothes in a washing machine; special super-speed tubular separator can also separate gas mixtures of different densities; the use of solid particles with different densities or particle sizes to settle in liquids at different speeds, some of them settle The centrifuge can also classify solid particles according to density or particle size. Centrifuges are widely used in chemical, petroleum, food, pharmaceutical, mineral processing, coal, water treatment and shipping sectors.

       In ancient China, people used one end of the rope to tie the pottery pot, held the other end of the rope, and flicked the pottery pot to generate centrifugal force to squeeze out the honey in the pottery pot. This was the early application of the principle of centrifugal separation.

written by Decanter Centrifuge \\ tags:

May 23

Analysis of actual difference between belt press machine and decanter centrifuge

1 Applicable media problems

Decanter centrifuge is suitable for all kinds of sludge; belt machine is also suitable for all kinds of sludge, but for oily, viscous, remaining activated sludge, it needs a large amount of medicine and dehydration is difficult.

2 The problem of feed control

The decanter centrifuge can automatically adjust the slip and torque according to the change of the feed concentration, and the belt machine must be manually adjusted.

3 Problems of solid recovery rate and dosage

The solid recovery rate of the centrifuge is indeed higher than that of the belt machine, but this does not mean that the solid recovery rate of the belt machine cannot be used if it is low. In fact, the belt filter must be returned to the front and reprocessed.

The dosage of medicament is added. A 15 × 104t / d urban sewage treatment plant designed by the author adopts a decanter centrifuge for dehydration. The measured consumption of PAM per ton of dry sludge after production is 1.7-2.0kg. The lower the consumption of medicine with machine (PAM) is generally 4kg / (t [dry mud]).

4 Power consumption problem

The difference in power consumption is not as claimed by the manufacturer of the machine. It is actually controversial. The decanter centrifuge manufacturers will also say that their centrifuges use less electricity. The author speaks a jargon here: power consumption differs mainly depending on the model and the amount of processing capacity.

The noise of the centrifuge is large, but the noise with the machine is not the machine itself, mainly the sound of washing water, the sound feels better than the centrifuge;

5 The life of the belt press machine

The bearing life of a good-quality belt press machine is theoretically 20a, which is similar to the life of the host machine. The filter belt needs to be replaced frequently. The filter belt is generally replaced continuously for 2000h operation. If it is intermittently operated and maintained well, then it depends on the length of use and shutdown In contrast, regardless of whether it is a domestic or imported belt machine, the filter belt can generally be replaced with a domestic filter belt, so the cost of replacing the filter belt is not high, and the current domestic equipment of the decanter centrifuge is reliable, stable, and easy to maintain and maintain.

In theory, the running time of the belt press machine can also run for 24 hours. Of course, the continuous operation of the belt machine is not as reliable as the centrifuge.

6 Calculation of operating expenses

When the belt filter press dehydration machine manufacturer calculates the dehydration and centrifuge core operating costs, there are many problems in the calculation method used. The operating costs mainly include: pharmaceutical fees, electricity costs and water costs. In addition to the belt machine, there are downtime costs and flushing costs. The author took an 8 × 104t / d sewage treatment plant as an example to calculate the actual operating cost of sludge treatment. Therefore, from the perspective of operating costs, the use of centrifuges and Not higher than with the machine.

7 Investment issues

From the perspective of investment, if the above-mentioned belt integrated machine is an imported high-end product, the full set is about 200,000 US dollars, and the domestic production is lower, while the above set of centrifugal concentration dehydration machine is about 300,000 US dollars, and the domestic production is lower, due to the difference in product grades. Or other specific reasons, the price will be outstanding, but generally speaking, the product of the same grade, the price of the centrifuge is higher than that with the filter, however, because the centrifuge occupies less space, the construction cost of the sludge concentration and dewatering room can be saved In some cases, the two basically offset each other, which means that the investment costs of the belt machine and the centrifuge are similar.

From the above analysis, we can draw the following conclusions: The advantage of the centrifuge is that the mud is dry and the closed environment is good. It can run continuously without flushing water. The advantages of the belt machine are power saving and low noise. Therefore, whether to use centrifuge or belt machine for sludge (concentration) dehydration must be analyzed concretely.

written by Decanter Centrifuge

May 08

Sewage and sludge in the paper industry need to be treated in a sludge thickening tank. Now the main sludge treatment process is: pre-dehydration, dewatering by decanter centrifuge, crawler dehydration. After the sludge concentration is increased, the dewatering efficiency of the decanter centrifuge will increase accordingly. But it should be avoided that the sludge concentration becomes too high, which will cause the sludge transportation pipeline to block the concentration is too low.

    The papermaking wastewater mainly comes from the two production processes of pulping and papermaking in the paper industry. Both processes discharge large amounts of wastewater. The wastewater from pulping is the most polluted. The waste water discharged during washing is black-brown, which is called black water. The concentration of pollutants in black water is very high, BOD is as high as 5-40g / L, and it contains a lot of fibers, inorganic salts and pigments.

    The process of the decanter centrifuge to deal with the papermaking sewage is to make the sludge pass through the gravity dehydration zone, then to the pressure dehydration zone, and finally to the pressurized dehydration zone. After these three steps, a relatively dry mud cake is produced. The concentration suitable for dehydration is generally about 10%.

The decanter centrifuge has the advantages of low investment, automatic control, continuous operation, low energy consumption, high dehydration efficiency, easy management, low maintenance cost, low noise, and low dosage of chemical agents. Therefore, dewatering decanter centrifuges are recommended for papermaking wastewater and mud dewatering projects.

GN dewatering decanter centrifuge is P series decanter centrifuge with beach angle of 11 degrees. GN P series decanter centrifuge is usually used dewatering and thickening purpose. It is widely used for maximum dewatering requirements of municipal and industrial wastewater sludge. The dewatering decanter centrifuge is designed for easy separation material include large particle size, high density difference of 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 P series decanter centrifuge.

written by Decanter Centrifuge

Mar 12

News: GN Decanter Centrifuge for Oil Sludge Treatment to Brunei

This GN Decanter Centrifuge is specially designed for Oil Sludge Treatment and exported to Brunei.

2020.03.12 Decanter Centrifuge for Oil Sludge Treatment

Oil sludge is a mixture of oil, water and solids. Treatment with oil sludge would recover a lot of oil and water for reuse.
It is also an ideal solids disposal solution. The more oil and water are extracted, the more energy and resources could be
saved. GN oil sludge treatment products mainly include decanter centrifuge, oil-water separator and thermal desorption

GN P-series decanter centrifuge is mainly designed for the dewatering purpose. The beach angle of this series is 11
degrees. It is widely used for maximum dewatering requirements of municipal and industrial wastewater sludge. The
dewatering decanter centrifuge is designed for easy separation material include large particle size, high density
difference of 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 P 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 taxus chinensis, honeysuckle and liquorice, clarification,
concentration and dehydration of salt crystals, etc.

2020.03.12 Oil Sludge Treatment Equimpent

GN can not only provide users with Dewatering Decanter Centrifuges, but also provide users with turnkey solutions for
dewatering process, including solutions for material transportation, classification and dewatering. Rely on GN’s rich
production line of separation and conveying equipment, more and more reliable and advanced equipment will be manufactured
for users all over the world.

written by Decanter Centrifuge \\ tags: ,

Feb 28

The selection of the Decanter Centrifuge is essentially to find a specific machine that can meet the process requirements according to the physical properties of the materials and the process requirements.


The physical parameters related to the selection mainly include:

1.The parameters of Solid-liquid separation: the solid phase concentration of the suspension, the range of the particle size of the solid particles, the weight difference between the solid and the liquid, and the liquid viscosity.
2.The parameters of Solid-liquid-liquid separation: the solid-liquid-liquid 3-phase concentration, specific gravity difference, and viscosity.
3.Moreover, it is also important to consider the machine materials and structures such as pH, flammable and explosive, and abrasion resistance.

Another issue related to the selection is the purpose of separation. Different models have different purposes. Is it to obtain a solid phase with low water content, a liquid phase with high clarity, or both solid and liquid phase content are required, or a higher requirement for one phase and a lower for the other phase appropriately?

During the selection process, we may encounter two situations. One is an industrial problem, such as DDGS project of corn distiller’s grains, kaolin classification, lubricant purification, sludge dewatering, etc. The separation process and equipment have basically matured in the industry. When buying machines, you only need to access the existing Users for reference. The other is about the new problem encountered in the development of new products, which requires the necessary physical property test and separation experiment.

363 Decanter Centrifuge 2

Supporting facilities for Decanter centrifuge
A complete separation system, in addition to the decanter centrifuge, we also need a variety of other equipment and instruments to support it in order to put into normal operation. Normal supporting facilities include:
① Pretreatment device: crusher, shaker, desander, thickener, etc.
② Feeding device: feeding pump, draining pump, screw conveyor, flow meter, agitator.
⑧ Instrument control device: starting device, monitoring device, display and safety device.
④ Lighing, safety protection and cleaning equipment.

written by Decanter Centrifuge \\ tags: ,

Sep 30

GN Sold two more 30 inches Decanter Centrifuge to US Customer. A solid bowl centrifuge (also known as decanter centrifuge) continuously separates solid materials from liquids in the slurry and in the wastewater treatment stage plays a very important role. In the whole mud system, decanter centrifuge is the 5th purification equipment. There is a differential speed between the decanter bowl and the scroll, which is created by a gear unit on the industrial decanter centrifuges. The differential speed determines the solid content in the outfeed. GN decanter centrifuges not only easy to install and can be fast to starting up and shutting down but also needs small space operation.GN Solids America LLC has 5 different sizes of Decanter Centrifuge from 9, 14, 18, 22, and 30 inches. Five areas that give GN Decanter Centrifuges advantage competitive advantage in the Solid Control industry.1. Patent horizontal design with SS2304 casting and build for long life usage. 2. Safety locking system for safety awareness. 3. Easy to maintain 4. Designed for a variety of applications 5. more process flexibility and higher levels of performance. GN decanter centrifuges range of applications such as 1. Food Processing (wine, fruit and vegetable juice, coffee and tea, Animal protein) 2. Petrochemical/ Oil (Refining, Dewatering, oil well drilling, Waste oil stream recycle) 3. Waste recycling (Cleaning of wash water, Municipal wastewater )4. Fish Processing (Fish meal, Fish oil)5. Chemical (Herbal medicines, Chemical extraction) 6. Mineral processing (kaolin clay and calcium carbonate)7. Organic chemical industry (Organic intermediate and end products)8. Polymer industry (Thermoplastics for example PVC, synthetic rubber and fibers)9. Inorganic chemical industry (Bleaching agents, Acids, silica products).  GN decanter centrifuges sold worldwide because of extreme performance, reliability, and cost-effectiveness, they are functional, durable and take on key functions in many different industries.201909301720

written by Decanter Centrifuge

Sep 06

We discussed about dark colored centrate.

In the optimization of decanter centrifuges, there are other considerations.

  1. Gray, forming centrate
  • Sometimes the discharged centrate carries gray color, and sometime with foams on it. Dosage of flocculants needs to be adjusted according to accommodate the changing solids concentration
  • Optimization of liquid ring. When decanter centrifuge is in operation, there is a liquid ring on the wall of rotating bowl. A thin liquid ring means dryer solids
  • The strength of flocculants. When flocculants comes into rotating bowl, its relative speed to solids rotating together with the bowl is the rotating speed of bowl, which can be a big number. The flocculants needs to be accelerated to this speed. In order to accelerate, flocculants particles will be exerted a strong shearing force. The flocculants needs to be strong enough to withstand the huge force and will not collapse. Some companies have developed some kinds of strong flocculants;
  1. Low dryness

Solids dryness depends on many factors. Below is a summary of the impact of different parameters on the dryness of solids

  • If feed flow rate is lowered, solids dryness increases;
  • If flocculants flow rate increases, solids dryness increases;
  • If auger torque increases, solids dryness increases;
  • If differential speed decreases, solids dryness increases;

Factors impacting solids concentration of discharged liquid:

  • If feed flow rate increases, solids concentration in liquid increases;
  • If flocculants dosage decreases, solids concentration in liquid increases;
  • If auger torque increases, solids concentration in liquid increases;
  • If differential speed decreases, solids concentration in liquid decreases.

It can be seen that it is impossible to optimize the performance of decanter centrifuge without some kind of automation. And all the influencing factors needs to be taken into the algorithm to make performance optimization. Field optimization is much more complex than what we can see on paper.


written by Decanter Centrifuge

Aug 16

Decanter centrifuge is a very important processing tool in a wide scope of liquid/solid separation situations. The solid-bowl scroll-discharge centrifuge (which is usually called decanter centrifuge) is the workhorse of a wide range of liquid/solid separation activities in different industry sectors including mining, oil & gas, vinery, wine, chemical industry, etc.. In environmental protection decanter centrifuge can effectively perform dewatering of waste sludge, an important application of decanter centrifuge. Because of this application decanter centrifuge is recognized well and is considered an indispensable piece of equipment in the industry. GN Solids Control manufactures full series of decanter centrifuges, from 9” to 30”, to meet the needs of different application of many industrial applications.

In theory decanter centrifuge is a relatively simple machine. However in the manufacturing process it is far more complex than it is thought. Usually the rotating assembly contains a bowl rotating at very high speed (sometimes as high as 10K RPM) with an auger (or also called screw conveyor). Slurry is pumped into the rotating assembly by a pump through a feeding tube, clarified liquid decants out from one end of the rotating bowl and the separated solids is moved to the other end of the rotating bowl and discharged out from exiting opening. The biggest advantage of decanter centrifuge is its ability to separate high concentration of solids from liquid at pretty high throughput speed, with small liquid left in the separated solids. Decanter centrifuge can handle very high solids concentration, sometimes as high as 80% of liquid volume. Decanter centrifuges made by GN Solids Control work effective well. Solids discharged from GN Decenter centrifuge contains very small amount of water that the solids can be stacked without much seepage from the solids. However there is a lot of consideration to be made for the decanter centrifuge to perform properly and there are a lot of variables to consider when designing one system.18-inch-decanter-centrifuge

written by Decanter Centrifuge

Jul 26

GN Dewatering System Sold to Canada, customer use for slurry waste solutions. Slurry Categories as follow 1. Directly drilling soil from non- contaminated job sites 2. Hydro slurry from non-contaminated Hydro excavation requires less labor than conventional digging methods. After vacuum and roll off truck finished, GN the Dewatering system will be perfect solution for it.

The Dewatering System included

  1. Feeding hopper with High G shale Shaker model number GNZKR-1230 capacity 10-150t/h Storage tank size 3800 x 2200 x 1512 mm with 2 agitators both 5.5kWand 2 Slurry pump one is 22kW another is 5.5kW both pump control by the VFD system.
  2. HDD CBM Shaker tank

GN Double Deck Finder Shaker model number GNZS706 E with 140 m3/h (616GPM) capacity 6 pcs screen with adjust angle -1~ +5 degree. And GN desilter model number GNZJ594E-12N 120m3/h (528GPM) capacity 3 pcs screen with adjust angle -1~ +5 degree. One Slurry pump with a 22kW motor with Shaker and desilter tank size 10369 x 2100 x 2312 mm. 2 agitators with 11kW.

  1. Decanter Centrifuge

GN GNLW553C-VFD 22 inches (550mm) decanter centrifuge, capacity with 90 m3/h (400 GPM) support   with screw pump GNG60A-150 15kW capacity 60m3/h. Centrifuge skid not only supports the centrifuge but also can adjust the height. Under the centrifuge come with storage tank and transfer pump model number GNSB3X2B -7.5J flow rate at 30m3/h (132 GPM) motor power with 7.5kW, the speed with 1450 rpm

  1. Dose Machine

This comes with 3 compartments with 3 set agitator can automatic powder chemical dosing. Capacity 2000L/Hour, Tank Volume 2000L, Hopper Volume 45L

For more information please contact GN sales representative at Web: www.gnsolidsamerica.com/ www.gnsolidscontrol.com

Add: 6710 Windfern Rd, Houston, TX 77040


written by Decanter Centrifuge

Jun 13

GN Solids Control is strong brand for the manufacturing of decanter centrifuge in China.

Decanter centrifuge decants solids continuously from liquid by a auger inside the rotating bowl to flow out from solids discharge holes. It is widely used in different industry sectors for separation purposes.

Decenter centrifuge comprises of rotating bowl, auger rotating at differential speed and gear box. Some model use variable frequency controllers to control the speed of both the bowl and the auger, to control their absolute rotation speed, and to control the differential speed between the bowl and the auger.

Its working principle. Once slurry comes into the rotation bowl, it will be facing the intense centrifugal force generated by the rotation of the bowl. Usually solids are heavier than liquid and stronger centrifugal force is applied to solids, and thus pushing them toward the wall of the bowl, and the lighter phase (liquid) is under less centrifugal force and thus it “floats” on top of the settled solids, forming a liquid layer. As there is a differential speed between the rotating bowl, and the rotating auger, deposited solids will be pushed towards slowly towards cone side of rotating bowl, continuously flow out from discharging port.

GN Solids control has long history to manufacture decanter centrifuge and its decanter centrifuge is used in ten of countries playing an important role in solids control of oil and gas drilling process.

In the oil and gas drilling process, there is a big challenge for decanter centrifuge as the concentration of solids changes tremendously. And the existence of hard particles generates serious wear on equipment. Also drilling mud go through different solids control equipment. These equipment perform in very different ways, making the situation very complex. It is extremely difficult to maintain decanter centrifuge in overall optimized performance.

In order to handle these challenges, GN Solids Control performed sound research and development work, and invested a good sum of money into it. The result is a series of decanter centrifuge with outstanding performance.

  1. GN uses duplex stainless steel, which is much stronger than regular 316 stainless steel. This allows GN Solids Control to manufacturing decanter centrifuge with much higher rotation speed and thus much higher separation coefficient. The other advantage of duplex stainless steel is strong resistance to wear, making decanter centrifuge by GN Solids Control last much longer than those made of regular 316 stainless steel;
  2. Technique employed to manufacture the bowl. GN Solids Control uses centrifugal casting technique to make the bowl of decanter centrifuge. This technique generate a much uniform distribution of stainless steel mass and a much reduced challenges in balance the bowl, and the balancing of whole system;
  3. GN Solids Control extends speed range of bowl balancing to both the bowl & auger themselves. GN performs low speed balancing, medium speed balancing and high speed balance for both of them to ensure these two critical rotating parts are well balanced throughout the speed spectrum. And this whole speed balancing is also performed on the rotating assembly. This allows smooth and quiet operation of decanter centrifuge by GN Solids Control;
  4. GN Solids Control also use tungsten carbide to enhance the life of all parts prone to wear, including solids discharge port, auger blades, end of auger, and any parts that are exposed to strong solids flow. All these significantly extend the life of GN decanter centriguge;
  5. GN solids control also performed in-depth R&D work and developed a control system which control the operation of decanter centrifuge. It uses advance algorithm to predict the performance of decanter centrifuge and adjust system operation parameters in a timely manner, this greatly enhance equipment performance and reduced down time.


Field application shows that with the support of all the above mentioned technology, decanter centrifuge by GN Solids Control outperforms decanter centrifuge  by famous manufacturer, which is a few times more expensive than GN decanter centrifuge.

GN is the right name for you to choose in solids/liquid separation challenges.22-inch-decanter-centrifuge

written by Decanter Centrifuge