What Does a Coalescing Filter Do & How Does a Coalescer Work?
March 26, 2019 Welcome
In downstream oil and gas operations, separation of the various crude fractions is done for the purpose of purification or commercialization. The separation process involves removing several liquids and gases from the hydrocarbon mix in separation units. Some examples include gas-oil, fuel-gas, and water-gas separation. A piece of vital equipment used for this purpose is the coalescer.
What Is a Coalescer?
A coalescer is a piece of industrial equipment used in the oil and gas processing and petrochemical industries to perform coalescence. Coalescence is the process of causing an agglomeration (coming together) of liquid aerosols to form larger droplets which are large enough to be drained away gravitationally. A coalescer operates in reverse to an emulsifier which creates emulsions.
A coalescer may be used on its own, or as a component of a larger separation unit. Selecting the right type of equipment will depend on the nature of the substance to be separated. For example, an oil coalescer or fuel coalescer can be used to recover oil or fuel from a water-oil mix respectively while a gas coalescer is used to separate gases from gas-fuel or gas-water emulsions.
Applications of Coalescers in Industry
Coalescers are widely used in downstream oil and gas operations and petrochemical industries for liquid-liquid or liquid-gas separation during product refining processes. For example, liquid-gas coalescers are used in the downstream sector to separate water vapor and liquid hydrocarbons from natural gas streams to ensure high product purity.
In addition, coalescers can be used to protect refining equipment from corrosion. In the petrochemical industry, coalescers as part of filtration systems to eliminate water vapor from products prior to storage.
Types of Coalescers
There are two basic types of coalescers used in the industry, based on the mode of operation; electrostatic and mechanical coalescers. The mechanical coalescer is the predominant type utilized in the oil and gas industry and petrochemical plants all over the world.
Electrostatic coalescers utilize electric charges (DC or AC, or a combination of both) to induce coalescence of liquid molecules onto the surface of a collection tank. They are especially useful in water-hydrocarbon emulsions and widely used in offshore production platforms. The electrostatic charges help to destabilize the emulsion by increasing the size of the molecules, causing them to fall to the bottom of the tank.
Mechanical coalescers utilize a series of baffle walls or coalescing filters to separate water/hydrocarbon condensate from emulsions and coalesce them into larger molecules. A common application is for water separation from liquid hydrocarbons or natural gas.
How Does a Coalescer Work?
Typically, the separating mechanism consists of a series of baffle walls or filters located at various points of the system. The system is designed such that the separation devices trap the various components of the mixture at intervals.
In the case of water-oil separation, baffle fibers separate the denser oil molecules and allow water molecules to diffuse and coalesce at a collection point underneath the baffle walls where they can be drained mechanically.
What Is a Coalescing Filter?
A coalescing filter is a device used to separate vapors, liquids, soluble particles, or oil from some other fluid through a coalescing effect. The coalescing effect is the coming together of liquid aerosols to form a larger whole which is easier to filter out of the system due to increased weight.
The filter consists of several progressive layers which perform specific functions; from separating solid particles to liquid molecules from a gas flow. Some common materials used as coalescing filters include borosilicate microfibers and semi-permeable membranes. A coalescing filter for natural gas separates water vapor and other particulates to improve product purity.
Oil and gas skid manufacturers like IFS offer a range of cost-effective separation systems to the downstream oil and gas and petrochemical industries.
How Does a Coalescing Filter Work?
The separation of emulsions using a coalescing filter generally involves the following steps:
- The product is passed through two or more filter elements placed at several points in the coalescer.
- The coalescing filters separate the constituents in phases, trapping one substance and allowing the other to pass through to collection points.
- The fluid that passes through coalesces into larger, heavier particles which are drained away mechanically. The efficiency of coalescence (and purity of the resulting fluid) is dependent on the quality of the coalescing media.
Effective & Reliable Product Separation with IFS
If you need equipment, expertise, or consultancy services for your product filtration, look no further than IFS!
Integrated Flow Solutions specializes in the design and fabrication of modular, engineered to order process systems for the oil and gas industry. We offer a range of modular fluid filtration and fuel gas conditioning systems to meet the most stringent requirements for product purity.
All equipment is performance engineered and quality assured to meet international standards for quality and reliability. We also offer a team of experts for consultancy services for your organization.
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