Vapor-Liquid Separator Design
Publication Date: 2018-Mar-13
The IP.com Prior Art Database
Many processes require separation of two-phase mixtures and efficient liquid distribution. Such devices include, but are not limited to, distillation columns (with random or structured packing), absorption columns, chromatographic columns, and heat exchangers (shell-and-tube, plate-and-fin, coil wound, printed circuit, etc.).
Vapor-Liquid Separator Design Many processes require separation of two-phase mixtures and efficient liquid distribution. Such devices include, but are not limited to, distillation columns (with random or structured packing), absorption columns, chromatographic columns, and heat exchangers (shell-and-tube, plate-and-fin, coil wound, printed circuit, etc.). The separation equipment shown in Figs. 1-4 looks like conventional vapor-liquid phase separators (knockout drums), while the actual separation devices may look quite different. They could be closed vessels, open vessels, or pieces of equipment performing multiple functions. They could be located within other pieces of equipment such as columns or heat exchangers, or externally. The separation devices may be arranged concentrically. For example, the first separator may be located inside the second which is contained within the third. The separation devices include, but are not limited, to knockout drums, standpipes, bulkheads (such as of a column or a heat exchanger), annular ring shelf along the periphery, cylindrical sections, conical sections, troughs, or a combination of all of the above. They may utilize gravity, buoyancy, centrifugal force, and/or diameter change resulting in velocity change of the fluid and disengagement of liquid from the vapor. Actual conduits between the vessels may or may not be present. The liquid or vapor could flow via direct flow into the next vessel. Liquid may overflow from one separator to another. The conduits may be of any type, including tubing, breather pipes, downpipes or troughs. Shutoff valves may be present in any of the liquid lines to prevent liquid rundown. For additional separation of liquid droplets, they may contain demisters, mesh pads, vanes, or other mist eliminators. Fig. 1
Fig. 1 shows a simple example. The bulk flow entering the separator, for example through a nozzle, is two-phase (shown as 2-, a mixture of liquid and vapor). It undergoes separation into vapor (V) and liquid (L). The separation takes place in the separation device (1). The liquid from the separation device enters the liquid distributor (D). Fig. 2
. Figure 2 shows two separation devices in series. As before, the bulk flow entering the first separation device (1) is two-phase. It first undergoes crude separation into vapor (V) and the second two-phase mixture: mostly liquid with some vapor still entrained (L / 2-). The second two-phase mixture enters the second separation device (2). The second separation device performs near-total separation of the second two-phase mixture producing clear liquid (L). The vapor streams from both devices may be combined. The liquid from the second separation device enters the liquid distributor (D). Fig. 3
Fig. 3 shows a series of three separation devices. As in the previous example shown on Fig. 2, the first device may do the crude separation. The liquid from the first device may still contain some vapor. It may be fed to the second an...