Inside the Dissolved Gas System: What EDUR Multiphase Pump Technology Changes in a DAF Train
The Dissolved Gas System Is the Bottleneck People Forget
A dissolved air flotation train is judged on its separation performance, but the separation is only as good as the bubbles feeding it. The dissolved gas system decides bubble size, bubble uniformity and how much of the supplied gas actually dissolves. When that unit underperforms, the flotation cell takes the blame even though it is not the problem.
The SINOKLE EDUR high-efficiency dissolved gas system is built around core components of the German-made EDUR multiphase pump, combined with independently developed patented technologies in swirl centrifugation and ultra-fine bubble generation. It is the core supporting system of the dissolved air flotation process, and against traditional dissolved gas systems it upgrades all four practical dimensions: dissolved gas efficiency, operational stability, adaptability and economy. Deployment covers landfill leachate, oily refinery wastewater, oilfield wastewater and a wide range of other industrial streams.
Why Bubble Quality Decides Removal Efficiency
The EDUR multiphase pump relies on a special open impeller structure in which gas and liquid are mixed in a highly dispersed manner inside the pump. Dissolved gas solubility of the liquid reaches 100% saturation, far above traditional dissolved gas systems. The unit then produces ultra-fine bubbles with an average diameter of ≤26μm, uniform in size, with a specific surface area increased by 10 times.
Smaller, more numerous and more uniform bubbles collide and adhere to pollutant particles far more effectively. Capture and removal of fine suspended solids and emulsified oil is therefore significantly better than with traditional processes, and the improvement shows up as effluent quality rather than as an instrumentation reading.
Fewer Parts, Fewer Failure Points
Gas is drawn in directly through the vacuum at the pump inlet. That eliminates air compressors, pressure vessels and release devices, which simplifies the system structure, reduces moving parts and piping connections and lowers failure points. The unit can stably convey liquid with a gas content of up to 30%, holding dissolved gas performance even when flow, gas volume and water quality load fluctuate. Shock resistance is strong and there is no mechanical power component wear, which is a meaningful advantage on the variable streams that industrial wastewater treatment actually delivers.
Process Time, Not Just Effluent Quality
Ultra-fine bubbles work in synergy with a swirl centrifugal force field to strengthen the coalescence and separation of pollutants and bubbles. That lets the supporting flotation process run a hydraulic residence time as short as 1-5 minutes, far below traditional dissolved gas systems, while single-stage de-oiling efficiency stays above 90% and removes oil droplets of ≥0.3 microns together with fine suspended solids. The benefit is not only cleaner water but a smaller, faster plant, because the overall treatment train shortens and the equipment shrinks for the same duty.
Where the Energy Goes
The open impeller structure of the multiphase pump delivers strong energy-saving performance, and the streamlined design with few auxiliary components and short pipe runs compounds it. Overall system energy consumption falls by more than 40%. No chemical demulsification or coagulation aid is required, which removes reagent cost at source. Scum and sludge output drops, lowering solid waste disposal cost. And with no wearing parts, labour and O&M expense fall as well.
Site Constraints and Deployment
The system uses a compact integrated design that avoids large-scale civil works, with a footprint of only 1/8-1/3 of a traditional dissolved gas system. That matters wherever industrial site space is tight. Skid-mounted customisation allows dissolved gas parameters to be matched to project capacity and water quality characteristics, and the unit interfaces seamlessly with CDFU swirl dissolved air flotation and CDOF catalytic oxidation processes. Installation and commissioning are convenient, so the construction cycle shortens along with the footprint.
Materials, Service Life and What Stays Out of the Water
Core contact parts are made of special anti-corrosion materials and tolerate the corrosive media found in industrial wastewater, operating within ≤50℃ and ≤0.1mPa conditions with a long overall service life. Structurally there are no wearing parts, and the unit supports online cleaning and backwashing, so dissolved gas performance is maintained long term with maintenance frequency and maintenance cost at only 1/3 of the conventional figure.
Equally important is what the system does not add. Separation is purely physical throughout: no chemical addition, no metal leaching and no concentrate generation, which avoids secondary pollution at source. Fully sealed pressurised operation prevents odour diffusion and removes leakage risk, addressing environmental discharge standards and industrial production safety requirements together. A supporting intelligent control system enables remote monitoring and unattended operation, so operating status can be tracked in real time.
Field Results and Where It Fits
The system serves as the core dissolved gas supporting unit for landfill leachate pre-treatment, and adapts just as well to refinery electric desalting wastewater, oilfield fracturing flowback fluid, tank farm black water and food processing oily wastewater. It has been applied by benchmark refining enterprises including Sinopec and PetroChina as well as oilfield projects, with effluent oil content stably controlled at 150mg/L or less and performance held under low temperature, high emulsification and high salinity conditions.
For an operator upgrading a flotation process, the deciding argument is usually the combination: smaller footprint, lower energy consumption, less maintenance and no reagent. The SINOKLE position is that the dissolved gas system, not the flotation cell, is where the upgrade should start.