Liquid-liquid coalescers separate immiscible liquids, such as oil and water, by merging dispersed phase droplets into larger droplets that can be easily separated. Industries like oil and gas, petrochemical, chemical, and wastewater treatment commonly use coalescing systems.
The process typically involves passing the liquid mixture through a vessel or coalescer cartridge with a media that promotes coalescence. This media can be made from fibrous materials, meshes, or porous materials, all of which provide a large surface area and promote droplet agglomeration.
The coalescence mechanism follows several steps: capturing droplets on the media surface, promoting droplet collisions, merging the captured droplets, and continuously removing the coalesced droplets.
Coalescing systems are crucial for removing oil from water in oil-water separators, treating produced water in the oil and gas industry, and purifying liquids in chemical processes. These systems improve separation efficiency and reduce environmental impact by removing contaminants from liquid streams.
Industries requiring liquid separation often rely on coalescing systems. In the oil and gas industry, for example, separating oil from water ensures efficient processing and protects the environment. Coalescing systems also serve in chemical processing, wastewater treatment, and other sectors.
The primary goal of a coalescing system is to promote the merging of dispersed phase droplets into larger droplets, simplifying their separation from the continuous phase. The system typically passes the liquid mixture through a vessel or coalescer cartridge, with a media designed to improve the coalescing process.
Coalescers use various materials for their media, depending on the application. Fibrous materials like fiberglass, cellulose, or synthetic polymers offer high surface areas for capturing and retaining droplets. Meshes and porous materials also facilitate coalescence by enabling droplet collision and agglomeration.
The coalescing process unfolds in stages. As the liquid mixture flows through the coalescer, droplets contact the media’s surface. The media captures the droplets, providing a platform for interaction. As droplets accumulate, they increase the likelihood of collision.
When droplets collide, the energy causes them to merge, forming larger droplets. This process continues as the mixture moves through the coalescer. Over time, larger droplets form and separate from the continuous phase.
To enhance separation, coalescing systems may include additional components like settlement chambers or baffles. These features aid in gravity-driven separation of the coalesced droplets from the liquid mixture.
Coalescing systems offer several benefits in liquid-liquid separation. By reducing droplet size and improving droplet size distribution, they boost the efficiency of subsequent separation steps. This leads to better product quality, fewer losses, and improved process performance. Additionally, coalescing systems help protect the environment by reducing the discharge of liquid contaminants.
When selecting a coalescing system, it’s important to consider factors such as the properties of the liquids, desired separation efficiency, flow rates, and operating conditions. Tailoring coalescer design, media selection, and system configuration to the specific application ensures optimal separation performance.
Also check out, “Coalescer Filters“