CDFU (Cyclonic Dissolved Gas Flotation Unit)

Product Detail

CDFU (Cyclonic Dissolved Gas Flotation Unit) is a patented technology independently developed by Shenzhen Clear Science & Technology Co., Ltd (SINOKLE). Compared to traditional DAF (Dissolved Air Flotation), CDFU offers superior safety, environmental protection, a more compact structure, and a significantly smaller footprint (about 1/3 of traditional systems).

 

1. Technology Introduction

 

CDFU (Cyclonic Dissolved Gas Flotation Unit) is a patented technology developed by our company. It effectively integrates centrifugal separation, dissolved air flotation (DAF), and ultra-fine bubble generation technologies to efficiently separate oil and suspended solids from wastewater. Key features include:

 

· Micro-bubble generation technology

· DAF (Dissolved Air Flotation) technology

· Hydrocyclone technology

· Highly efficient coalescence

· Demulsification without chemicals

· Patented product

 

Process Diagram






Pic. 1 Process Diagram

 

2. Technical Principle

 

The wastewater to be treated is mixed with dissolved gas water. The mixture is then introduced into the flotation tank at a special angle along the tank wall. This creates a stable cyclonic flow field through dynamic flow and the internal structures of the tank. Centrifugal force generated by the flow causes micro-bubbles and oil droplets to collide, adhere, and coalesce rapidly, forming floating oil.

 

The floating oil rises and enters the internal oil collection cylinder, from where it is discharged into the floating oil collection system. Simultaneously, the separated exhaust gases are treated via an exhaust system. The treated wastewater flows out from the outlet of the CDFU.

 

3. Introduction of Cyclonic Centrifugation Technology

 

Dissolved gas water is mixed with wastewater and flows into the equipment, generating a cyclonic flow. This process increases the likelihood of collisions between bubbles and particles. Due to the weak centrifugal effect, oil emulsification is prevented. Micro-bubbles, with their high stability and large specific surface area, efficiently adsorb small particles. This ensures that the suspended matter in the effluent has a small median particle size and low content.

 

4. Technical Advantages

 

·Short Retention Time:

The oil-water separation process is rapid, with a retention time of only 1 to 3 minutes—about one-sixth of traditional equipment.

 

·High Efficiency:

The equipment effectively separates floating and free oil (oil droplets with particle sizes of 30-100μm), achieving removal efficiencies of up to 99%.

 

·No Chemicals:

With a small bubble diameter (D50 ≈ 25μm), the equipment can remove up to 90% of emulsified oil (droplets sized 0.1-20μm), performing exceptionally well without the need for chemical agents.

 

·Low Maintenance and Operating Costs:

The simple internal structure minimizes the risk of scaling and clogging, especially in high-salinity environments, resulting in reduced maintenance and operational costs.

 

·Automation:

The system maintains precise control over liquid levels and pressure despite fluctuations in water volume and oil content. It operates fully automatically and delivers stable effluent quality.

 

·Small Footprint:

The CDFU uses a skid-mounted design, occupying a minimal footprint and optimizing space utilization. This design also simplifies assembly and construction.

 

5. Comparison between Traditional Technology and CDFU









Application Industries:

Petroleum refining, power generation, metallurgy, pharmaceuticals, printing and dyeing, municipal, landfill leachate, river wastewater treatment, and more.

 

6. Case Studies

 

·Case 1 (2017):

Produced water treatment and re-injection at PetroChina Changqing Oilfield

 

·Oil content of influent: ≤ 1,500ppm

·Treatment capacity: 20m³/h

·Treatment equipment: Two-stage CDFU + walnut shell filter

·Effluent oil content: ≤ 30ppm, SS ≤ 30ppm

·Filter effluent oil content: ≤ 10ppm, SS ≤ 10ppm

·Median particle size: ≤ 5μm

 

 

Pic 2. On-spot equipment dual-stage CDFU+ walnut shell filter                 Pic 3. Influent vs. Primary effluent vs. Secondary effluent

 

·Case 2 (2019):

PetroChina Dushanzi Petrochemical electric desalting sewage treatment

 

·Sewage oil content: ≤ 2,000ppm

·Treatment capacity: 100m³/h

·Treatment equipment: Two-stage CDFU

·Effluent oil content: ≤ 10ppm

 

 

Pic 4. Dual-stage CDFU of on-site equipment                Pic 5. Secondary effluent vs. Primary effluent vs. Influent

 

Case 3 (2021):

Sinopec conventional gas field produced liquid (condensate) treatment

 

·Sewage oil content: ≤500ppm

·Treatment capacity: 30m³/h

·Treatment equipment: Single-stage CDFU

·Effluent oil content: ≤20ppm (indicator requirement: ≤50ppm)

 

 



Pic 6. Single-stage CDFU on-spot equipment                                                  Pic 7. Influent vs. Effluent