Technical Overview
Technical Introduction
The CDFU (Cyclonic Dissolved Gas Flotation Unit) is a patented technology independently developed by our company, representing an internationally advanced level of innovation. This technology creatively integrates cyclone centrifugal separation, ultra-fine bubble generation, and dissolved-air flotation into a unified system, achieving highly efficient and comprehensive removal of multiple pollutants from various difficult-to-treat wastewater streams.
A patented technology of SINOKLE, the CDFU is China's first next-generation high-efficiency compact enclosed pressurized flotation technology. By organically combining cyclone separation, next-generation micro-bubble generation, and dissolved-air flotation, it achieves rapid and highly efficient separation of free oil, emulsified oil, and suspended solids from wastewater.
Product Parameters
Product Parameters
| Parameter | Specification |
|---|---|
| Capacity (Q) | ~500 m3/h |
| Media Temperature | <80 °C |
| Operating Pressure | >0.1 mPa |
| System Pressure Drop | >0.05 mPa |
| Inlet Requirements | Oil content: <1000 ppm / SS: <200 ppm |
| Oil Removal Efficiency | >90% |
| SS Removal Rate | >85% |
| Gas Media | Air, N2, natural gas, etc. |
Technological Advantages
Technological Advantages
Technical Comparison
Technical Comparison
| Comparison Item | Conventional DAF | CDFU (Cyclone DAF) |
|---|---|---|
| Treated Wastewater | Oily wastewater (with suspended solids) | Oily wastewater (with suspended solids) |
| Residence Time | 15–40 min | <5 min (only 1/8–1/3) |
| Oil Removal Efficiency (single stage) | 60%–85% | >90% |
| SS Removal Rate (single stage) | 50%–70% | >80% |
| Removal Particle Size (>80%) | >5 µm | <3 µm |
| Bubble Diameter | 5–100 µm (average uniformity) | 5–30 µm (excellent uniformity) |
| Pressure Cost | Moderate | Lower |
| Automation Level | Manual, open-type | Automatic, enclosed operation |
| Sludge Discharge Method | Mechanical scraper — poor reliability | Pressure discharge — no mechanical drive, high reliability |
| Safety & Environment | Odor leakage — safety and environmental hazards | Enclosed pressurized operation — no odor leakage, safe and eco-friendly |
Application Cases
Application Cases
CDFU Process Flow Diagram
Typical application process flow of the CDFU cyclone dissolved-air flotation unit, enabling highly efficient and comprehensive removal of oil and suspended solids from oily wastewater.
Refinery Oily Wastewater Treatment Project
CDFU operates in fully enclosed pressurized mode — safe, eco-friendly, skid-mounted for easy installation, and fully automated to reduce O&M costs.
CDFU Cyclone Dissolved-Air Flotation
The perfect fusion of cyclone centrifugal separation and dissolved-air flotation (DAF) technology — CFD-optimized design for leading high-efficiency oil-water separation
Product Overview
World-Leading Compact Cyclone Dissolved-Air Flotation Separation Technology
What is CDFU?
CDFU (Compact Cyclonic Dissolved Gas Flotation) is a patented product independently developed by SINOKLE, combining cyclone centrifugal separation with dissolved-air flotation (DAF), and optimized through CFD design to create a high-efficiency oil-water separator.
Wastewater mixed with dissolved-air water enters the CDFU, where cyclone centrifugal force drives rapid collision and adhesion between micro-bubbles (5–30 µm) and oil droplets, forming a floating oil layer.
Working Principle
Perfect Synergy Between Cyclone Centrifugal Force and Dissolved-Air Flotation
Dissolved-Air Mixing
Wastewater and micro-nano bubbles (5–30 µm, D50 ~25 µm) are high-shear mixed in a multi-stage dissolved-air pump.
Cyclone Separation
The mixed fluid enters the flotation tank tangentially, forming a stable cyclone field where centrifugal force drives bubble-oil droplet collision and agglomeration.
Oil-Water Separation
Floating oil rises to the oil collection chamber and is discharged; clean water exits from the bottom, with a portion recycled for dissolved-air circulation.
Process Flow
Feed Water
Oily wastewater
DAF Pump
Multi-stage dissolving
Mixer
Collision & adhesion
CDFU
Cyclone separation
Clean Water
Compliant discharge
Product Features
Ultra-High Oil Removal Efficiency
Free / surface oil >=99%, emulsified oil 80–90%
Ultra-Low Energy Consumption
Energy usage only 10% of IGF; gas consumption 1–3%
Zero Chemical Dosing
No chemicals required — no sludge generated, recovered oil can be reused
Ultra-Short Residence Time
Only 1–3 minutes
Compact Skid-Mounted
Footprint only 1/3 of conventional DAF
Low Maintenance
Scaling-resistant; liquid level control precision +/−5 mm
Structural Features
Innovative Dual Tangential Inlets
Dual-tangential angle design increases cyclone velocity and centrifugal acceleration, enhancing flotation efficiency and reducing residence time.
Core Dual Flotation Zones
A central cylinder divides the tank into inner and outer flotation zones, generating stronger centrifugal force and maximizing space utilization.
Functional Cyclone Sand Removal
Conical bottom design uses centrifugal force to throw particles to the inner wall, preventing sand accumulation.
Validated CFD Optimization
CFD detailed flow field simulation optimizes internal component design and ensures stable cyclone performance.
Technical Comparison
CDFU vs Conventional DAF
| Parameter | Conventional DAF | CDFU |
|---|---|---|
| Residence Time | 15–40 min | <5 min |
| Oil Removal Efficiency | 60–85% | >90% |
| Removal Particle Size | >10 µm | <2 µm |
| Bubble Diameter | Non-uniform | 5–30 µm |
| Operation Mode | Manual / Open | Fully Automatic / Enclosed |
CDFU vs Leading Market CFU Products
| Parameter | SBL | VEOLIA | SIEMENS | CDFU |
|---|---|---|---|---|
| Bubble Diameter | >500 µm | 100–500 µm | 5–75 µm | 5–30 µm TOP |
| Residence Time | 0.5–1 min | 1–2 min | 3–5 min | 1–3 min TOP |
| Free Oil Removal Rate | 80–90% | >90% | ≥96% | ≥99% TOP |
| Emulsified Oil Removal | Nearly ineffective | Poor performance | 50–70% | 80–90% TOP |
| Chemical Dosing | Required | Required | Minimal | Not required OK |
| Oil Recovery | Not possible | Not possible | Mostly | Full recovery OK |
| Stability | Low | Low | High | Extremely high TOP |
| Control Precision | Low | Low | Low | +/−5 mm TOP |
Key Conclusions
CDFU uses a multi-stage dissolved-air pump to generate ultra-fine bubbles (D50 ~25 µm), combined with dual tangential inlets and a dual flotation zone design. With zero chemical dosing, it achieves free oil removal of ≥99% and emulsified oil removal of 80–90%. It delivers the highest oil removal efficiency, lowest operating cost, and simplest maintenance — making it the optimal solution for oilfield oily wastewater treatment.
