Liquid / Liquid Coalescer Filters

Liquid / Liquid Coalescer Filters

High-Efficiency Phase Separation for Challenging Emulsions

In petrochemical, fine chemical, and specialty process industries, liquid-liquid phase separation is often one of the most technically demanding operations. Stable emulsions, surfactants, low density differences, and aggressive chemical environments frequently render conventional gravity separation or simple filtration ineffective.

CMI Liquid / Liquid Coalescer Filters are engineered to deliver reliable phase separation performance in applications involving low interfacial tension, high contaminant loading, and complex chemical systems.

Separation Challenges Addressed

Liquid-liquid separation efficiency is primarily governed by three key parameters:

• Interfacial Tension (IFT) – determines emulsion stability and separation difficulty
• Density Difference – affects droplet settling velocity
• Viscosity – influences flux, pressure drop, and coalescence kinetics

In many modern chemical processes, interfacial tension can fall well below 20 dyne/cm, and in some cases approach sub-1 dyne/cm, making conventional separators ineffective—especially in the presence of surfactants and strong solvents.

Working Principle

Stage 1 – Pre-Filtration

• Removes solid particles and bulk contaminants
• Protects the coalescing media from premature fouling
• Initiates pre-coalescence by combining fine droplets into larger ones

Stage 2 – Coalescence & Separation

• Emulsion flows through the coalescing filter element
• Dispersed-phase droplets are captured and agglomerated within the media
• Graded pore structure promotes continuous droplet growth
• Enlarged droplets detach and separate under gravity
• Separated phases are collected and discharged independently

This staged design enables stable and controlled separation even for highly stable emulsions.

Key Capabilities

• Handles influent with high dispersed-phase loading
• Effective separation under ultra-low interfacial tension conditions
• Wide operating temperature range
• Excellent chemical resistance to acids, alkalis, and organic solvents
• Low residual contamination in both separated phases
• Suitable for continuous and critical process operations

Coalescing Media & Construction

• High-strength metallic core and structural support
• Engineered coalescing layers for droplet capture and growth
• Drainage layers to promote rapid phase disengagement
• Chemically resistant materials for extended service life

Material selection and internal structure can be customized based on fluid chemistry, operating temperature, and separation requirements.

Typical Applications

• Petrochemical and refining processes
• Fine and specialty chemical production
• LNG and gas processing liquid separation
• Oil removal from water streams
• Water removal from hydrocarbons and solvents
• Reaction and purification phase separation

System Configuration Options

• Horizontal or vertical coalescer housings
• Integrated pre-filtration and coalescing stages
• Custom flow capacity and vessel design
• Optional separator stage for polishing performance
• Instrumentation for level monitoring and control

Why Choose CMI

• Strong understanding of complex liquid-liquid separation mechanisms
• Proven performance in stable emulsion systems
• Flexible design for a wide range of process conditions
• Integrated filtration and separation engineering capability
• Technical support from design to commissioning