ACHEMA 2000: Try Braided Column Packings for Better Distillation Peformance
Nagaoka International Corp. (Osaka, Japan) used the ACHEMA 2000 forum to roll out a new type of structured packing for distillation columns. The heart of the packing is a three-dimensional mesh of wire that is draped from a distribution tray at the top of a column. Liquid will flow down this mesh in an ordered fashion that is said to provide significantly better mass transfer than conventional structured packings, which are usually a flat surface with corrugations or crimping.
Called Super X-Pack, the mesh can be supplied in steel or other alloys, as was as nonmetallics such as fiberglass, ceramics or engineering plastics. The wires are tightly woven like a rope coming out of the distributor plate, then open up into the honeycomb mesh for the desired length. The wire is woven into either a triangular "raster" called 3X-Pack, or a square raster, 4X-Pack. In either case, the indent is for the wires to be wetted by downcoming fluid, while gas can pass freely through and over the mesh, provided efficient heat and mass transfer. The f-factor load range in vacuum can be up to six, and the number of theoretical units (1/NTU) is 6-11. A full-fledged system has the distributor tray at the top with multiple downcomer tubes, the mesh, and a collector plate at the bottom that the wires are tied to.
Specific applications include:
By Nick Basta
For more information:
Nagaoka USA Corp., 11943 FM 529, Houston, TX 77041. Tel: 713 937 1590.