The Cavitation Air Flotation (CAF) system is a pressure-free dissolved air and mechanical air-breaking flotation separation device designed and manufactured by our company. Featuring a unique vortex-shaped aerator that directly generates microbubbles, this product provides a simplified, energy-efficient, and user-friendly solid-liquid separation solution for removing oil, suspended solids, and colloidal substances from wastewater.
- Structure and Working Principle
- Core structural composition
The system typically features an integrated rectangular enclosure structure, with the core unit comprising:
- Vortex concave aerator: The core component consists of a high-speed rotating impeller (or rotor) and a fixed stator (or diffuser). The impeller, driven by the motor, rotates at high speed to create a localized negative pressure area (vortex concave zone).
- Separation zone: Sufficient retention time is provided for the bubble-floc complex to float and separate, with a clear water collection and discharge system installed at the bottom.
- Scrap scraping system: typically employs chain scraper or rotating scraper arm, designed to continuously or intermittently transfer floating slag into the collection trough.
- Chemical reaction zone (optional): Installed before the air flotation unit, this zone delivers coagulants (PAC) and flocculants (PAM) to destabilize fine suspended particles and colloids, forming flocculent flocs that can be captured by bubbles.
- Working Principle
- Bubble generation: Unpressurized air is directly drawn into the low-pressure vortex (cavitation) zone formed by the high-speed rotating impeller through the air inlet at the top of the aerator. In this region, air and water undergo intense shearing and mixing, resulting in the formation of a cluster of larger microbubbles (typical bubble diameter range: 50-100 micrometers).
- Contact and Adhesion: The microbubbles generated are thoroughly mixed with the treated wastewater flowing into the reaction zone from the aeration system during the upward movement. The bubbles collide with oil droplets and suspended flocs in the wastewater, resulting in adhesion.
- Separation and Removal: Particles carrying air bubbles become less dense and rapidly rise to the water surface, forming a scum layer that is removed by a skimmer. The clear water is discharged from the bottom or the overflow weir at the end of the air flotation tank.
- Core technical features
- The system architecture is relatively simplified: it eliminates the complex pressure dissolved air system required by traditional dissolved air flotation (DAF), including dissolved air tanks, high-pressure pumps, dissolved air release devices, and air compressors, resulting in a simpler process flow and equipment configuration.
- The system may have lower energy consumption, as the main energy consumption is concentrated in the motor of the vortex aeration machine, which eliminates the energy consumption of the high-pressure dissolved air pump. Under certain treatment scale and water quality conditions, the total energy consumption of the system may have certain advantages.
- Operation and maintenance are relatively convenient: Since there is no precision air release device and high-pressure system, the daily operation parameters are few, the maintenance points are relatively simple, and the technical requirements for operators may be relatively low.
- Bubble characteristics and application scenarios: The generated bubbles typically have a larger diameter compared to high-efficiency dissolved air flotation. It is suitable for removing pollutants with lower specific gravity and strong hydrophobicity (such as animal and vegetable oils, fibers, and certain suspended solids), and is widely used in the pretreatment of oily wastewater.
- Space-saving optimization: The integrated compact design with modular configuration based on processing capacity helps save installation space.
- Main technical parameters
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Parameter item
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Description / Reference range example
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per unit processing capacity
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Standard model range: 10 m³/h – 300 m³/h (higher capacity available with multi-unit parallel configuration or custom design)
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retention time in the separation zone
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Typically 15–30 minutes (closely related to water quality and coagulation efficiency)
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aerator power
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Based on processing capacity and model compatibility, the typical power range for a single unit is 3.0 to 15 kW.
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average diameter of bubble
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Typically ranging from 50 to 100 micrometers
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surface load
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The design reference range is typically 3 – 7 m³/(m²·h).
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Main material
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Corrosion-resistant carbon steel, stainless steel (SS304/316L) available
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Key Settings
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Vortex coffer aerator, sludge scraper, and electrical control system; optional complete dosing and flocculation system
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- Typical Application Fields
This system is particularly suitable for treating wastewater containing floatable pollutants, commonly found in the following industries:
- Food and oil processing wastewater: pretreatment for oil removal and suspended organic matter elimination in wastewater from meat processing, edible oil refining, dairy products, and catering industries.
- Paper and textile wastewater: used to remove fine fibers from white water, or hydrophobic dye particles and oils from textile wastewater.
- Petrochemical and mechanical processing: primary treatment of wastewater containing mineral oil and lubricating oil, such as oilfield produced water, metal processing coolant, and steel rolling wastewater.
- Other industries: tanning, ship ballast water and other oily and suspended solids wastewater treatment.
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