Filter Separator is used to remove liquid, small solids (created by the tubing and wing erosion) and other particles from the flow steam. Filter separators, like other gas-liquid separators, can be horizontal and vertical; the most common type is horizontal. If there is a large amount of water in coming gas, structure of filter separator is designed to have a “boot” in the bottom of the separator connected with two similar tubes parallel to each other. Retention period required between 3 and 5 minutes for hydrocarbon (oil)-water separation by settling. Sizing the dimension of the filter separator’s each section depends on the calculations and design of manufacturer or engineering company.
Filter separator consist of coalescing filters and mist extractor inside of its vessel, usually have quick opening closures for maintenance and replacement of the filters.
“Filter separators and coalescing filters are required, when droplet sizes below 3 microns”
- Typical Horizontal Filter Separator
Filter separators have a wide application in gas pipelines, as well as the gas processing plants, for example, acid removal units, when after passing filters separators catch the liquids and condensed hydrocarbons coming from the absorber. In gas processing, adequate inlet separator and filter separator are required to prevent foaming due to the chemical contamination. If absorber is downstream from amine unit, glycol unit, or compressor, a filter separator is required. Also, filter separator and coalescing filter used to prevent fine mists from entering the absorber.
Solid removal efficiency of the filter separator is 100% when size of solids is 3 microns & larger, and 99%, when size of solids are 0.5-3 microns, while liquid removal efficiency is 98% when size is 8 microns & larger.
Efficiency of filter separator depends on particle size, distribution of particles, and liquid loading.