What is the role of a demister in a gas processing unit?

The role of a demister in a gas processing unit is to remove entrained liquid droplets from a gas stream. Demisters, also known as mist eliminators, are devices installed in gas-liquid separators, distillation columns, and other equipment to improve the separation efficiency. As gas flows through a process vessel, it can carry small liquid droplets with it. These droplets can cause problems downstream, such as fouling of equipment, corrosion, and reduced product quality. Demisters work by providing a surface for the liquid droplets to impinge upon, coalesce into larger droplets, and then drain away due to gravity. Common types of demisters include wire mesh demisters, vane demisters, and fiber bed demisters. Wire mesh demisters consist of a knitted wire mesh pad that provides a large surface area for droplet collection. Vane demisters use a series of vanes to change the direction of the gas flow, causing the droplets to impinge on the vane surfaces. Fiber bed demisters use a bed of fibers to capture even smaller droplets. By removing entrained liquid droplets, demisters improve the performance and reliability of gas processing units.