In the modern industrial separation process, the decanter centrifuge is widely used in chemical, pharmaceutical, metallurgical, mining, petroleum, papermaking, environmental protection, municipal sewage and other industries due to its strong continuity, large processing capacity and high degree of automation. However, in the face of long-term operation conditions of high-solid content, high-corrosive and strong-impact materials, equipment wear and corrosion have become key factors restricting the service life, operation stability and customer return on investment of the decanter centrifuge.
Especially in typical working conditions such as mine tailings, coal slime dehydration, petroleum drilling cuttings, phosphorus chemical industry, papermaking black liquor, and pharmaceutical waste liquid, strong wear and high corrosion coexist, which puts forward extremely high material, structure and process requirements for the equipment.
Analysis of common wear and corrosion problems of decanter centrifuge
In actual operation, the wear and corrosion of decanter centrifuge often occur alternately or simultaneously, which is mainly reflected in the following aspects:
1. Wear problem
Impact wear caused by high-speed rotation: After the material enters the drum, it hits the inner wall and spiral blades at high speed under the action of centrifugal force, causing the metal surface to gradually wear, especially the slag outlet, the front end of the spiral conveying section, the drum cone section and other areas are the most serious.
Grinding effect of solid particles: When processing high-solid content, hard particle suspension (such as slag, sand, silicon powder), solid particles cause long-term scratches and impacts on the surface of the equipment, resulting in local rapid wear and tear of the equipment.
Sliding friction wear: The relative movement between the spiral blades and the drum may also cause material wear, affecting the dynamic balance and separation efficiency of the equipment.
2. Corrosion problem
Chemical corrosion: In the chemical, pharmaceutical, printing and dyeing, food and other industries, the processing liquid usually contains strong acids and alkalis, organic solvents or chlorides, which corrode the metal structure of the equipment, especially 304 stainless steel is prone to pitting and crevice corrosion in chloride ion media.
Electrochemical corrosion: When different metals are in contact or electrolytes are present, galvanic corrosion may occur, damaging key components.
Stress corrosion cracking: Under the dual influence of alternating loads and corrosive environments for a long time, microcracks may expand or even break in components.
Core solution path for wear and corrosion resistance of horizontal screw centrifuge
1. Upgrade of material selection: source control of wear and corrosion resistance
We select the following wear-resistant and corrosion-resistant metal materials and composite materials according to different working conditions:
High-strength stainless steel (such as SS316L, 2205, 2507 dual-phase steel): has excellent corrosion resistance and strength, suitable for seawater, salt water, strong acid and alkali scenes.
Tungsten carbide composite material (WC-Co spraying): with a hardness of more than HV1200, suitable for strong impact particle wear areas, especially slag outlet and spiral blades.
2. Surface strengthening process: creating a double protective layer of corrosion and wear
For high-risk areas, we use advanced surface treatment technology to improve the surface performance of materials:
Plasma sprayed cemented carbide: suitable for large-area wear-resistant layer construction, with excellent adhesion and erosion resistance.
Laser cladding technology: by melting high-performance powder to form a metallurgically bonded wear-resistant layer on the surface of the parent material, the structure is dense and the fatigue resistance is strong.
PTFE Teflon coating: suitable for conveyor belts and sliding contact surfaces, with significant anti-corrosion and anti-adhesion effects.
3. Structural design optimization: reduce wear and corrosion risks from the source
The spiral blades are welded with carbide guards or replaced with ceramic guards to achieve local reinforcement.
Multi-section cone structure reduces the solid impact speed and delays the wear of the cone section.
The replaceable wear-resistant sleeve design is convenient for maintenance and avoids the scrapping of the entire machine.
The internal streamlined structure reduces the secondary rebound and vortex formation of materials and reduces abrasion.
4. Sealing system upgrade: prevent the leakage of corrosive liquids and internal contamination
We use multi-stage sealing structure and high-grade sealing materials:
Fluororubber and polytetrafluoroethylene sealing rings are suitable for special media such as strong acids, alkalis, oils, etc.
The combination of labyrinth structure + mechanical seal effectively blocks the contact between the medium and the bearing.
Pressurized sealing oil system to prevent gas and liquid penetration.
Wear and corrosion resistance have become key indicators to measure whether a decanter centrifuge is truly suitable for complex working conditions. We always adhere to the customer’s working conditions as the core starting point, deeply understand the separation challenges of various industries, and provide customers with centrifugal separation equipment that can truly “fight hard battles” through continuous iteration of materials, structures and processes.
In the future, we will continue to promote the application of cutting-edge technologies such as intelligent materials, 3D printed components, and digital twin diagnosis in decanter centrifuges, helping more companies to achieve more efficient, safer and more economical production goals in high-load and high-challenge separation environments.
