Coalescers COAL
Media-assisted droplet growth for gravity separation. High-surface-area media that merge fine dispersed oil droplets into large, easily separated drops — a low-pressure-drop enhancer for gravity de-oiling.
System Schematic
Representative process-flow — configured to your streamUnderlying Technology & Scientific Principle
A coalescer presents oily water to a high-surface-area oleophilic medium (fibres, mesh, plates or structured packing) on which small dispersed oil droplets wet, accumulate and merge into much larger droplets. The larger droplets shed from the medium and rise rapidly under gravity in a downstream settling section, turning a stable dispersion into an easily separated two-phase flow.
Working Mechanism
Water passes at low velocity through successive layers of coalescing media. Droplets are intercepted on fibre or plate surfaces, spread as a film, drain along the medium under gravity and release as enlarged droplets typically 10–100× the inlet size. A quiescent downstream chamber lets the enlarged droplets rise to a surface oil layer that is decanted.
Separation / Removal Efficiency
Lifts free / lightly dispersed oil removal from ~60 µm down to 10–20 µm cut size; commonly polishes inlet 200–500 mg/L OiW to 10–30 mg/L without chemicals.
Operating Principle & Parameters
Approach velocity 0.005–0.02 m/s; low pressure drop (0.1–0.5 bar). Performance degraded by surfactants, high shear pumps and solids loading — a strainer or pre-filter is usually required.
Flow Rates & Volumetric Capacities
Cartridge/plate packs from 5 m³/h up to 500+ m³/h per vessel; common as a packaged enhancement inside CPI / API tanks or as standalone vessels.
Fluid Media Compatibility
Polypropylene, glass-fibre, stainless mesh, or structured oleophilic plate packs in CS/SS pressure vessels. Suited to clean dispersed-oil duty across upstream and refining service.
System Schematic & Process Integration
Installed as an internal enhancement in API/CPI separators or as a dedicated vessel upstream of flotation, nutshell or membrane stages where droplet growth is the bottleneck.
Options / Variations Available
Fibre-bed cartridges, plate-pack coalescers, structured-mesh internals; combined liquid–liquid–gas coalescer-separators for gas-treating service.
System Complexity & Automation Level
Low — no moving parts; differential-pressure monitoring triggers cartridge replacement or backflush.
Applications & Performance Delivered
API / CPI separator enhancement
Internal coalescing pack drops cut size and tightens outlet OiW without expanding footprint.
Fuel & lube oil dewatering
Two-stage coalescer-separator removes free water to ppm levels in hydrocarbon streams.
Pre-flotation droplet growth
Enlarges droplets so downstream DAF / IGF removes them with less chemistry.
Contaminant Removal Profile
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