Liquid/Liquid Coalescing Filters
Liquid/Liquid Coalescing Filters
Maximum Performance for Dispersing Industrial Emulsions and Separating Two Immiscible Liquids
As Dantechs Systems and Filter Solutions; we offer high-efficiency Liquid-Liquid Coalescing Filter Elements that meet global standards for the separation of immiscible liquids (emulsions) – one of the most common challenges faced in oil, gas, refinery and petrochemical plants. We flawlessly separate free water mixed into hydrocarbon lines or oil phases accumulating in waste water flows at your facilities using mechanical and chemical methods.
Principle of Operation: Emulsion Breaking and Gravity Separation
Liquid-liquid coalescing filter cartridges work by capturing microdroplets (stable emulsions ranging from 1 to 50 µm) that are dispersed within one another and do not settle under normal conditions. As the fluid passes through specialised technical layers that are either hydrophilic (water-loving) and oleophobic (oil-repellent) or the reverse, the microdroplets adhere to one another, merge and grow (the coalescence effect). These large droplets, reaching sizes in the millimetre range (1 to 5 mm), rapidly settle under the influence of gravity due to the difference in density between the two liquids (Stokes’ Law) and separate into their respective phases.
General Technical Specifications and Standards
Based on international manufacturer standards available online (Pall, Brother Filtration, etc.), the technical parameters of industrial liquid-liquid coalescer elements are classified as follows:
1. Structural Materials
The filter media is selected according to the chemical aggressiveness, temperature and interfacial tension of the process fluid:
- Glassfibre (Technical Fibreglass): This is the most commonly used depth media. It delivers excellent performance in separating water from hydrocarbon streams.
- Polyester and Fluoropolymer Structures: These provide full chemical compatibility for the separation of aggressive chemicals, acids, caustics or high-temperature hydrocarbons.
- External Protection and Support: Stainless steel (304/316SS) or tin-plated steel internal/external cage assembly.
2. Micron Ratings & Efficiency
- Micron Ratings: Typically manufactured with 0.5, 1.0, 5.0, 10 and 25 micron ratings. To preserve the filter’s service life prior to the coalescer process, it also incorporates a mechanical fine filter layer to trap solid particles.
- Efficiency Level: Absolute particle retention efficiency of up to 99.99 per cent. Guarantees to reduce free water in hydrocarbons to 15 ppmv or below.
3. Dimensions
Filter elements are manufactured in standard sizes to fit industrial housings perfectly, or can be made to measure:
- Outer Diameter (OD): Typically available in 3.75‘ (~95 mm), 4.0’ (~102 mm) or 6.0" (152 mm High Flow) standard sizes.
- Lengths: Depending on the body’s flow capacity, 10‘, 20’, 30‘, 40’, 60‘ and 80’ inch options are available.
- Connection Types: Double-ended open (DOE), 222 O-ring-sealed or threaded (1/2" - 13 UNC, etc.) mounting caps.
Critical Industrial Applications
Liquid-liquid coalescing elements are deployed across a wide range of applications to maintain process purity and extend equipment lifespan:
- Petroleum and Refinery Solutions: Removal of free water and solids from petrol, diesel, jet fuel (Jet A-1) and gas oil.
- Petrochemical Lines: Separation of amine residues from Liquefied Petroleum Gas (LPG), and removal of water from light hydrocarbons.
- Chemical Processes: Separation of acids, caustic or hydrogen peroxide from process solutions in chemical raw material or synthesis processes.
- Environmental and Wastewater Systems: Removal of free oils from water in discharge lines leading to wastewater treatment works (WWT), ensuring compliance with environmental regulations.