Study On Supercritical Fluid Dyeing Device And Dyer Internal Flow Field Simulation

Supercritical fluid dyeing (SFD) is a new textile processing technology using supercritical carbon dioxide, instead of water, as medium for dyeing, which eliminates the dyehouse wastewater completely. Current supercritical fluid dyeing processes and devices are summarized in this thesis. The problems of current supercritical fluid dyeing devices are pointed out, especially for dyers.By taking the advantage of the structure of traditional water dyeing equipment and considering the characteristics of supercritical fluid dyeing process, a new type of supercritical fluid dyeing device is devised. This new type of supercritical fluid dyeing device is especially suitable for dyeing textile with wide breadth. Both the textile and the dye solution move during dyeing process in this new dyer. This new feature overcomes the shortcomings of the traditional supercritical fluid dyer for introducing color difference, and improves the efficiency of dyeing process as well.The operating mechanism and design principles of the new supercritical fluid dyeing device are introduced. Structure and design methord of the pressure vessel and dye distributor are given. And a new type high-presure canned motor is presented. Also, the circulation pump selection methord is given.Based on the feature of the new supercritical fluid dyeing device, a full set of supercritical fluid dyeing process is determined, which can be industrialized. The specific operation process for dyeing in the new device is described, and the design parameters and selection methods of important components are given. The new device can meet nearly all of the supercritical fluid dyeing condition published so far.Internal flow field of the new supercritical fluid dyer is simulated by numerical methord. At first, a 2D numerical simulation is used to optimize the dyer internal structure, and as a result the fluid short cut phenomenon is avoided. Then a 3D numerical simulation is used to optimize the perforated plate of dye distributor parameter. After the optimization, the 3D simulation result agrees with 2D's within reasonable scope.