It’s very important to protect the decanter centrifuge from the corrosion problems. GN separation is professional in manufacturing and maintaining decanter centrifuges. After the warranty period of decanter centrifuge, the corrosion defects and their treatment methods are as follows:

1. Pitting corrosion, the following three conditions are minor, so they can not be dealt with temporarily.

1) Large pitting corrosion zone, but no cracks;

2) For scattered corrosion pits, the maximum corrosion depth has not exceeded half of the wall thickness value (not including the calculated thickness of the corrosion margin) required for the calculation of the strength of the vessel;

3) There is no serious chain pitting in the scattered pitting area.

2. There are three treatment methods for single corrosion defects under the skin of the decanter centrifugeand individual pit corrosion defects with an area less than 40mm.

1) When it is shallow, you can leave it alone

2) When it is deeper, the sanding method can be adopted, but the wall thickness should meet the strength requirements after sanding;

3) If the strength requirements cannot be met after grinding, surfacing treatment should be used.

3. When several large pits with a single area diameter of not more than 40mm exist at the same time, there are two situations.

1) When the distance between two adjacent defects is greater than 120mm, they can be treated as individual pit corrosion defects;

2) When the distance between two adjacent defects is less than 120mm and greater than 50mm, and the corrosion depth does not exceed 60% of the wall thickness, surfacing treatment can be used.

4. When the local corrosion defect of the centrifuge does not affect the strength requirement and the area is large (such as large area spots or ulcerative corrosion), it can be treated with metal spraying.
5. The local uniform corrosion defects of the centrifuge can be dealt with according to the following three conditions.

1) The corrosion area can be large or small, as long as the depth of the defect does not exceed 40% of the original thickness of the wall, surfacing can be used;

2) When several uniformly corroded defects exist at the same time, the area of ​​a single piece is not greater than 50mm*50mm, and the distance between two adjacent corrosion areas is greater than 50mm, and the depth of the defect does not exceed 60% of the original thickness of the wall, it can be surfacing;

3) When there are too many corroded pieces or the distribution is too wide, cut and repair or replace the defective tube section or tube body can be used.

6. The overall uniform corrosion defect of the centrifuge is the least dangerous kind of corrosion defects. Generally, only anti-corrosion measures are used and no other treatments are performed.
7. The intergranular corrosion defect is one of the most dangerous defects. For this type of defect, preventive measures are mainly taken. Otherwise, this type of defect can only be replaced as a whole.

Recently, GN Separation, a leading manufacturer in sludge dewatering technology, successfully completed production on a batch of municipal sludge dewatering decanter centrifuges destined for a North African country. This substantial order includes three GNLW654-VFD dewatering decanter centrifuges and one 6500L Chemical dosing unit with 3 screw-type metering pumps.

In municipal wastewater treatment, sludge dewatering decanter centrifuges play a crucial role in reducing sludge moisture content, making it easier to manage and dispose of. A key feature of GN’s dewatering decanter centrifuge is the use of tungsten carbide for components that come into direct contact with sludge. Known for its exceptional hardness and wear resistance, tungsten carbide ensures these parts can withstand the abrasive nature of sludge, enhancing the centrifuges’ durability and reducing maintenance and operational costs.

These decanter centrifuges also incorporate dilute oil lubrication systems that continuously lubricate the main bearings. This real-time lubrication minimizes friction and wear, enabling smooth and stable operation and sustaining optimal performance over prolonged periods. Each GN dewatering centrifuge is equipped with temperature and vibration sensors that provide real-time operational data. This monitoring helps operators detect potential issues early, preventing costly repairs or downtime.

The inclusion of 4-VFD control cabinets further enhances the flexibility and efficiency of the centrifuges, allowing precise control over rotational speed, as well as the feed pump and dosing metering pump flow rates. This adjustable control is essential for optimizing the dewatering process according to the specific characteristics of the sludge, ensuring maximum efficiency and high-quality output.

Municipal sludge, which results from wastewater treatment, often contains high water content. During the dewatering process, the polymer dosing unit enhances equipment efficiency by enabling flocculation, where sludge particles form larger flocs that are easier for the centrifuge to separate. The polymer dosing unit optimizes sludge treatment by controlling flocculant dosage and timing, improving sludge dewatering efficiency and resulting in clearer water that meets environmental standards. The reduced sludge volume and water content also lower transportation and disposal costs.

This order completion marks a major milestone for GN Separation, reinforcing its presence in the African municipal sludge dewatering market. It highlights the company’s ability to meet the complex demands of international clients and its dedication to providing innovative, cost-effective solutions. Going forward, GN Separation remains committed to ongoing innovation, striving to deliver high-performance and affordable sludge dewatering solutions that contribute meaningfully to the industry.

Recently, GN Separation successfully completed the manufacturing of a Hydraulic Drive Decanter Centrifuge for deployment in a major starch production project overseas. Continue reading →

Before starting the decanter centrifuge, check in advance: whether the overload protection device is in normal working condition; whether the fastening bolts everywhere are loose; whether the drum can rotate normally; whether the moving parts and static parts are rubbed. Continue reading →

GN Separation has recently completed the assembly of two GNLW224 decanter centrifuges, known for their compact design that merges innovation with durability. These versatile machines are ideal for various industries, including environmental protection, salt chemicals, and oil & gas exploration.

The GNLW224 decanter centrifuge can exemplify GN’s dedication to technological excellence, featuring a bowl diameter of 220mm and a length-to-diameter ratio of 4.2. This design optimizes space while maintaining top-tier performance. With a rotational speed of up to 5000 RPM, the centrifuge delivers high-speed separation, generating powerful centrifugal forces to ensure superior separation efficiency. The bowl, made from duplex stainless steel 2205 through a centrifugal casting process, offers enhanced balance and resilience, capable of withstanding harsh operating conditions while reducing vibrations and extending the machine’s lifespan.

Supporting Diverse Industries

1. Environmental Protection: Sludge Dewatering

In the environmental sector, GN’s decanter centrifuge is widely used for sludge dewatering. Its ability to efficiently separate water from sewage sludge significantly reduces waste volume, lowering transportation costs and enabling more eco-friendly sludge management. The improved sludge dryness also supports energy recovery through anaerobic digestion, contributing to the circular economy in wastewater treatment facilities.

2. Salt Chemicals: Crystal Salt Dewatering

In the salt chemicals industry, the decanter centrifuge is crucial for crystal salt dewatering. Salt producers depend on precise separation techniques to achieve high-purity salt crystals, and this machine excels in delivering low moisture content in the final product, enhancing both quality and profitability. Its durable design efficiently handles abrasive salt particles, ensuring consistent performance over long periods.

3. Oil & Gas: Drilling Mud Recycling

The oil and gas industry generates significant amounts of contaminated drilling mud containing valuable drill cuttings and fluids. The decanter centrifuge offers an effective solution for separating these materials, reducing waste disposal costs and facilitating mud recycling. By separating solid particles from fluids quickly and thoroughly, it minimizes the need for fresh mud and improves overall drilling efficiency. The centrifuge’s high-speed operation ensures continuous processing, supporting uninterrupted drilling activities.

For more information about the decanter centrifuge, please contact GN Separation.