Chapter 1 | Technology for National Development: The Value
Proposition of Decanter Centrifuges
1.1 A Critical Link in the Environmental Protection Chain
Water environmental management is a systemic engineering endeavor
involving collection, conveyance, treatment, discharge, and
resource recovery.
Solid-liquid separation serves as the pivotal process that bridges upstream and downstream
operations:
- Receives mixed liquor from biological treatment (upstream)
- Supplies properly conditioned sludge for final disposal (downstream)
- Ensures stable operation of the entire wastewater treatment plant
(system-wide)
The decanter centrifuge is the core equipment for this critical step. Its performance directly impacts the efficiency, stability, and economics of the entire treatment system.
1.2 A Model of Technological Maturity
After decades of development, decanter centrifuge technology has
reached a high level of maturity:
- Design optimization: Length-to-diameter (L/D) ratio improved from early 3.0 to over
4.5
- Material advancement: Widespread use of duplex stainless steel and wear-resistant
ceramics
- Control evolution: Transitioned from manual operation to intelligent, interconnected
systems
- Application expansion: Now deployed across 30+ industries, from municipal wastewater to petrochemicals, food, mining, and
more
This progression reflects not only technical refinement but also
the journey of China’s environmental equipment industry—from catching up, to keeping pace, and now leading globally.
1.3 A Practitioner of Green Development
The environmental contributions of decanter centrifuges are evident
in measurable operational data:
| Performance Indicator | Typical Value | Environmental Significance |
|---|
| Sludge Volume Reduction | ≥80% | Drastically reduces landfill footprint |
| Cake Dryness (DS) | 25%–35% | Lowers energy consumption in incineration |
| Treated Water Reuse Rate | Up to >50% (process-dependent) | Conserves freshwater resources |
| Specific Energy Consumption | 0.5–1.0 kWh/m³ | Enables low-carbon, energy-efficient operation |
Chapter 2 | Principles Refined: The Philosophy of Simplicity in
Design
2.1 Fundamental Principle
The decanter centrifuge operates on a basic law of physics—Stokes’ Law of Sedimentation.
In gravity, denser particles settle slowly—too slow for industrial
needs.
By rotating at high speed, the centrifuge generates centrifugal forces hundreds to thousands of times stronger than
gravity, accelerating sedimentation by two orders of magnitude or more.
Core Relationship: Separation Efficiency ∝ Centrifugal Force × Residence Time
- Centrifugal force is determined by bowl rotational speed
- Residence time depends on bowl length and feed characteristics
Thus, decanter design fundamentally seeks the optimal balance between separation efficiency and processing
capacity.
2.2 Structural Breakdown
| Component | Function | Technical Highlights |
|---|
| Bowl Assembly | Generates centrifugal field for separation | Precision-machined; high dynamic balance |
| Scroll Conveyor | Transports settled solids to discharge end | Wear-resistant design; long service life |
| Differential Gear | Controls speed difference between bowl & scroll | High precision; robust reliability |
| Feed System | Distributes feed evenly into the bowl | Optimized flow path; minimal wear |
| Frame & Housing | Supports unit and ensures sealing | Rigid structure; reliable leak-proof seal |
| Control System | Monitors and adjusts operating parameters | Intelligent sensing; automatic regulation |
2.3 Key Technical Features
The advantages of decanter centrifuges can be summarized as the “Three Fulls”:
Fully Continuous:
Simultaneous feeding, separation, liquid discharge, and solids
discharge—no frequent start-stop cycles; stable throughput.
Fully Enclosed:
Complete sealing prevents leakage or odor escape—creating a safe,
clean working environment.
Fully Automatic:
PLC-based intelligent control with real-time monitoring; integrates
into central control systems for unattended operation.
Chapter 3 | Application Matrix: Serving All Sectors of the National
Economy
Thanks to its adaptability, the decanter centrifuge supports
diverse economic and social domains.
3.1 Municipal & Public Welfare Applications
Municipal Wastewater Treatment
→ Application: Sludge dewatering in urban WWTPs
→ Value: Ensures plant stability; protects urban water environments
Drinking Water Production
→ Application: Treatment of backwash sludge from water plants
→ Value: Achieves zero liquid discharge in production
Sewer Network Maintenance
→ Application: Dredging of drainage pipelines
→ Value: Rapid volume reduction; lowers transport costs
3.2 Industrial Production Applications
| Industry | Typical Application | Core Value |
|---|
| Petrochemical | Oily sludge separation | Recovers oil; reduces hazardous waste |
| Textile & Dyeing | Wastewater sludge dewatering | Ensures compliant discharge; removes color |
| Pulp & Paper | White water fiber recovery | Reuses raw materials; cuts costs |
| Food Processing | Juice clarification, protein extraction | Purifies products; adds value to by-products |
| Pharma & Fermentation | Microbial cell harvesting | Isolates target biomolecules |
| Electroplating & PCB | Heavy metal sludge dewatering | Minimizes hazardous waste; ensures compliance |
3.3 Environmental Remediation
- River Dredging: Rapid dewatering of high-solids dredged slurry
- Lake Restoration: Sediment volume reduction to restore aquatic ecosystems
- Soil Washing: Solid-liquid separation of soil leachate
- Landfill Leachate: Concentrate treatment for advanced disposal
3.4 Resource Recovery
In the era of the circular economy, decanter centrifuges are
evolving from treatment devices into resource recovery platforms:
- Food Industry: Recovery of proteins, starch, fruit fibers
- Petrochemicals: Reclamation of mineral oils and solvents
- Mining: Recovery of metal powders and concentrates
- Bioenergy: Extraction of organic matter from anaerobic digestate
Chapter 4 | Parameter System: Professional Basis for Equipment
Selection
All specifications below comply with industry standards and provide
reliable reference for client selection.
4.1 Standard Model Parameters
| Model | Bowl Diameter (mm) | L/D Ratio | Max Speed (rpm) | Max G Force | Main Motor (kW) | Weight (kg) |
|---|
| LW-350 | 350 | 4.0 | 3800 | 3000 | 30 | 2500 |
| LW-450 | 450 | 4.0 | 3200 | 3200 | 45 | 4200 |
| LW-550 | 550 | 4.0 | 2800 | 3000 | 75 | 6800 |
| LW-650 | 650 | 4.0 | 2400 | 2800 | 110 | 10000 |
| LW-760 | 760 | 3.5 | 2000 | 2500 | 160 | 14500 |
4.2 Performance Reference Data
Conditions: Municipal sludge, feed DS 2–4%, temperature 20–30°C
| Model | Capacity (m³/h) | Cake DS (%) | Effluent SS (mg/L) | Polymer Dose (kg/t DS) |
|---|
| LW-350 | 15–20 | 22–26 | ≤500 | 4–6 |
| LW-450 | 30–40 | 24–28 | ≤300 | 4–6 |
| LW-550 | 50–65 | 26–30 | ≤300 | 3–5 |
| LW-650 | 70–90 | 26–30 | ≤200 | 3–5 |
| LW-760 | 100–130 | 28–32 | ≤200 | 3–5 |
4.3 Configuration Selection Guide
| Feed Characteristics | Material Recommendation | Wear Protection | Drive System |
|---|
| Municipal sludge, neutral pH | SS304 | Standard | Dual VFD |
| Industrial wastewater, mild acid/alkali | SS316L | Optional | Dual VFD |
| High salinity / strong acid/alkali | Duplex stainless steel | Optional | Dual VFD |
| High sand content | SS304/316L | Hardfacing / Ceramic | Dual VFD or Hydraulic |
| Oily / prone to clogging | SS316L / Duplex | Hardfacing | Hydraulic differential |
| Explosive zones | SS316L | As required | Explosion-proof + Hydraulic |
Chapter 5 | Foundation of Quality: The Pursuit of Lean
Manufacturing
5.1 Manufacturing System
We understand that quality stems from meticulous attention to every
detail:
- Raw Material Inspection: All steel sourced from certified mills with material test reports
- Process Control: Critical steps monitored with traceable quality checkpoints
- Factory Acceptance Test: Every unit undergoes ≥4 hours of water-load trial run before
shipment
5.2 Key Manufacturing Processes
| Process Step | Technical Standard | Inspection Method |
|---|
| Bowl Machining | Roundness ≤0.05 mm | CMM (Coordinate Measuring Machine) |
| Dynamic Balancing | ISO 1940 G2.5 | Dynamic balancing machine |
| Welding | 100% NDT on pressure welds | Radiographic / Ultrasonic testing |
| Final Assembly | Clearances per engineering drawings | On-site measurement records |
Chapter 6 | Global Service: A Commitment Across Continents
6.1 Service Philosophy
We believe equipment delivery is not the end—but the beginning of a long-term partnership.
6.2 Service Scope
| Phase | Service Item | Deliverable |
|---|
| Pre-Sale | Feed analysis, model recommendation | Technical Proposal Report |
| In-Sale | Drawing confirmation, progress updates | Approved drawings, weekly reports |
| Commissioning | Remote guidance / on-site support | Commissioning Record |
| Training | Operation & maintenance training | Training Completion Certificate |
| After-Sale | Free warranty service | Service Report |
6.3 Spare Parts Assurance
- Maintain inventory of commonly used spare parts
- Supply genuine OEM components for critical parts
- Respond to urgent requests within 48 hours
Outlook | Walking Together Toward a Greener Future
At this new stage of development, the environmental protection
sector holds vast potential and profound responsibility.
We will steadfastly uphold our core principles:
Technology Leadership · Quality First · Customer Focus · Green
Development
With an open mindset, pragmatic approach, and superior products, we
aim to serve global ecological progress.
We look forward to partnering with stakeholders worldwide to:
- Advance environmental technologies
- Share opportunities in green development
- Protect the beauty of our shared planet
Closing Remarks
Every drop of water deserves care. Every inch of land deserves
protection.
Though compact in size, the decanter centrifuge carries the grand mission of ecological civilization.
We will continue to craft excellence with dedication, earn trust through integrity, and drive progress through collaboration—making our contribution to global water environmental protection.
