Design of ring and spider type spargers for bubble column reactor: Experimental measurements and CFD simulation of flow and weeping

In case of low H/D ratio bubble columns, sparger design governs the performance of bubble column reactors. Therefore, a comprehensive study was undertaken for single ring spargers, multiple ring spargers and spiders covering a wide range of hole diameters (2-6 mm), ring diameter (0.4-1 m), number of holes (19-90), number of rings (1-4), number of arms (3-5) and arm length (0.4-1 m). The flow distribution and critical weep point velocity was related to geometric and operating parameters. CFD simulations (ANSYS CFX-10.0) have been performed for all these cases and very good agreement was observed between the CFD predictions and experimental values of pressure, hole velocity and the critical weep point velocity. A step-wise design procedure for all types of sparger is presented along with a worked example. Further a new sparger (Wheel type) is proposed which would be superior to the existing spargers.