Analysis of CDFU technology: How cyclonic flow and micro-bubbles achieves efficient oil-water separation

In modern industrial wastewater treatment, efficient and rapid separation technologies are of vital importance. The Cyclonic Dissolved Gas Flotation Unit (CDFU) integrates multiple advanced processes including ultrafine bubble generation, dissolved air flotation (DAF) and cyclonic separation, providing an innovative solution for removing free oil, emulsified oil and suspended solids from wastewater.

Detailed Explanation of the Core Working Principle

The working process of the CDFU is a highly efficient and synergistic physical separation process, which mainly consists of three key stages：

Stage 1: Preparation and Release of Micro-bubbles

Air is dissolved in water under pressure to form saturated dissolved-air water. When the pressure is suddenly decreased, the dissolved gas released out, generating a large number of micro-bubbles with small particle sizes (typically 5–30 micrometers), dense distribution, and high stability. These ultrafine bubbles feature a larger specific surface area and stronger interfacial activity.

Stage 2: Efficient Adhesion Between Bubbles and Impurities

After oily wastewater enters the unit, it is fully mixed with the released micro-bubbles. During the slow upward floating of the bubbles, they collide with and firmly adhere to the dispersed oil droplets and suspended particles, forming "bubble-oil droplet" aggregates with an overall density lower than that of water.

Stage 3: Cyclonic Separation Enhancement

The mixture enters tangentially along the tank wall, creating a high-speed cyclonic flow field. Driven by centrifugal force, micro-bubbles and emulsified oil droplets are rapidly moved toward the central area, where they further aggregate and become larger. The bubble clusters adhering to pollutants accelerate upward to the liquid surface, forming a scum layer, which is finally discharged out of the system through an automatic control device.

Through the dual enhancement mechanisms of "micro-bubble adhesion" and "cyclonic centrifugation", this technology greatly improves separation efficiency and speed, achieving treatment effects that are difficult to reach with traditional single technologies.

On-site CDFU Equipment