Gas Flow Distribution's Numerical Simulation And Study Of Radial Flow Air Adsorber

With the development of air separation's scale, traditional horizontal and vertical axial flow adsorbers'fabrication and transporting were not satisfied, much effort of air separation manufactures was devoted to develop and study new-style radial flow adsorber which was widely used to air separation in recent years.Radial flow adsorber with variable mass flow was affected greatly by gas flow uniformity. Interactive data of momentum equation was twice than energy equation, Amendatory momentum equation using interactive coefficient was selected to describe variable mass flow. Effect factors and methods of flow distribution uniformity and the principle of structure's choosing were studied.Part and whole structure of adsorber's gas flow were simulated. Physical and mathematic models of perforated pipe distributor and cone distributor were established, the model was simplified by using porous media boundary, and distributors'performance was simulated by Fluent. The results showed that the performance of cone distributor was better than perforated pipe distributor. Physical and mathematic models of adsorber including molecular sieve were established, the model was solved by Fluent, it was concluded that mostly flow resistance was aroused by molecular sieve, by which flow uniformity was greatly affected; the uniformity performance could be improved by disposing molecular sieve reasonably, flow style was not critical at low pressure condition. Axial velocity uniformity of cone structure was 0.92~0.95, and perforated pipe was 0.90~0.91.'No flow zone'was eliminated by cone, so cone was the first choice of distributor type.Simulation results were compared with design and operation data to display simulation's scientific and reliability, the deviation between simulation and design data was 3%, and compared with operation data the deviation was 9%. The simulation model using porous media theory was proved to nicely predict flow resistance of molecular beds, some guidance could be supplied to optimizing adsorber's structure and three-dimensional simulation.