Swirl Centrifugal + Dissolved Air Flotation Dual Coupling: SINOKLE CDFU Solves Difficult Oily Wastewater Treatment

1. Flotation Technology: A Core Separation Technology in Industrial Water Treatment

Flotation (Dissolved Air Flotation, DAF) is an efficient solid-liquid / liquid-liquid separation technology in water treatment. Its core mechanism uses fine bubbles as carriers that adhere to suspended particles, oil droplets, and colloids in water to form bubble-particle complexes with a density lower than water, which quickly float to the surface under buoyancy to form scum, removed mechanically to achieve pollutant separation and water purification. With advantages such as high treatment efficiency, a small footprint, and flexible operation, it has become one of the core processes for treating oily wastewater, high-turbidity wastewater, and refractory wastewater.

1. Mainstream Classifications and Technical Features

According to the way bubbles are generated, flotation technology can be divided into the following four categories, suitable for different water quality scenarios:

2. Core Application Areas

Flotation technology has been widely applied across many industries, with industrial oily wastewater treatment as the core application scenario, specifically including:

• Oilfield water treatment: produced water, fracturing flowback fluid, offshore platform wastewater (core treatment process);

• Refining industry: electric desalting wastewater, tank farm black water, sour water (high oil content, highly emulsified);

• Other fields: food processing, papermaking, electroplating heavy-metal wastewater, landfill leachate, etc.

3. Technology Development Trends

Flotation technology is currently evolving toward high efficiency, intelligence, modularization, and customization:

• Ultra-fine bubble technology: bubble size reduced to 5-30 um, improving collision and adhesion efficiency with emulsified oil droplets, with single-stage de-oiling efficiency exceeding 90%;

• Material upgrades: key components use corrosion-resistant materials such as duplex stainless steel and titanium alloy, suitable for high-salinity and highly corrosive conditions (such as offshore platforms and high-salinity oilfield water);

• Process integration: the dual-technology integration of swirl centrifugation + dissolved air flotation achieves the dual effect of physical demulsification + high-efficiency separation;

• Intelligent control: AI algorithms adjust dissolved gas pressure and reflux ratio in real time, cutting energy consumption by more than 22%, while remote O&M enables unattended operation.

2. SINOKLE's CDFU Swirl Dissolved Air Flotation: An Innovative Solution for Difficult Oily Wastewater Treatment

SINOKLE's CDFU (Swirl Dissolved Air Flotation unit) is a technology iteration built on the traditional CFU. Its core innovation lies in the deep integration of swirl centrifugal separation and dissolved air flotation. It is specially designed for difficult oily wastewater treatment in oilfields and refineries, solving the pain points of traditional flotation such as hard removal of emulsified oil, high energy consumption, a large footprint, and poor corrosion resistance.

1. Core Technical Advantages

(1) Dual core of ultra-fine bubbles + swirl for efficient demulsification and de-oiling

• Bubble size is precisely controlled at 5-30 um (median about 25 um), perfectly matching 1-10 um emulsified oil droplets, increasing collision and adhesion efficiency threefold, with single-stage de-oiling efficiency >90% and suspended solids removal >85%;

• The swirl centrifugal unit optimizes the flow field through CFD to achieve preliminary separation of oil droplets from water, while the dissolved air flotation unit deeply removes residual emulsified oil, forming a double physical barrier that thoroughly cracks the stubborn emulsified oil problem.

(2) Pure-physical demulsification, a dual breakthrough in environmental protection and cost reduction

• No chemical agents are added throughout the process, eliminating oily sludge (hazardous waste) generation at the source; the separated waste oil can be directly recovered and reused, reducing hazardous waste disposal costs by more than 30%;

• It is dominated by static equipment with no mechanical slag scraping device, reducing failure points and maintenance needs, extending the maintenance cycle to 6 months, and cutting manual maintenance costs by 50%.

(3) Skid-mounted + customized materials for harsh operating conditions

• The compact skid-mounted design reduces equipment volume by more than 50% compared with traditional flotation, making it especially suitable for space-constrained scenarios such as offshore platforms and oilfield blocks, and shortening the deployment period by 40%;

• Key components use corrosion-resistant materials such as duplex stainless steel and titanium alloy, withstanding high salinity, high corrosion, and high temperature (below 80 C), suitable for harsh offshore environments and high-salinity oilfield water treatment.

(4) Intelligent O&M, efficient and stable

• Equipped with an IoT intelligent control system, it supports remote monitoring, parameter adjustment, and fault warning, enabling unattended operation;

• Shock load resistance reaches 110%, and it remains stably compliant even when influent water quality fluctuates; effluent oil content can be controlled at 10 mg/L or less and suspended solids at 20 mg/L or less, meeting stringent domestic and international (such as IMO) discharge standards.

2. Core Performance Indicators

3. Typical Application Cases

Case 1: Produced water treatment project at an oilfield in Africa

• Treatment capacity: 5,000 m3/d;

• Influent quality: oil content fluctuates greatly, severe emulsification;

• Treatment results: effluent oil content stably below 10 mg/L, far better than industry standards; the equipment runs stably and maintenance costs are reduced by 60%.

Case 2: Tank farm black water treatment project at a petrochemical enterprise in Xinjiang

• Treatment capacity: 3,600 m3/d;

• Technical solution: CDFUsingle-stage treatment;

• Core results: shock load resistance reaches 110%, operating energy consumption reduced by 40%, effluent oil content below 15 mg/L, meeting refinery wastewater discharge standards.

Case 3: PetroChina Petrochemical electric desalting wastewater treatment project

• Treatment capacity: 2,400 m3/d;

• Technical solution: two-stage CDFUcombined process;

• Treatment results: effluent oil content 10 mg/L or less, suspended solids 5 mg/L or less, achieving wastewater reuse and compliant discharge.

3. SINOKLE's CDFU: the preferred solution for oilfield and refinery water treatment

SINOKLE's CDFU, with its three core advantages of technological innovation, stable performance, and environmental protection with cost reduction, has become a benchmark product for oilfield produced water and high-oil refinery wastewater treatment, especially suitable for the following scenarios:

1. Offshore oilfield platforms: for space-constrained, highly corrosive, unattended conditions, the skid-mounted design and corrosion-resistant materials are a perfect match;

2. Highly emulsified oily wastewater: refinery sour water and fracturing flowback fluid; pure-physical demulsification technology efficiently removes stubborn emulsified oil;

3.3. High-salinity water treatment: oilfield reinjection water and high-salinity wastewater; duplex steel / titanium alloy materials withstand high-salinity corrosion and extend equipment life;

4. Retrofit of aging projects: no large-scale civil works needed; the modular quick-install design shortens the retrofit cycle and rapidly boosts treatment capacity.

In process design and project bidding in the environmental engineering field, SINOKLE's CDFU is not only a highly efficient treatment device, but also a technical highlight that enhances project competitiveness - its innovative swirl + flotation process, pure-physical environmental protection features, and intelligent O&M capability can significantly strengthen the technical sophistication and feasibility of a proposal, helping the project win the bid and operate stably over the long term.