Computer simulation of hydraulic flow in a mixing device with a diaphragm of special design installed in it

The results of computer simulation of hydrodynamic flow were presented using the FlowVision software package (Moscow, Russian Federation). This program has enabled creation of hydrodynamic flow models using three types of mixers: a mixer with the proposed diaphragm of special design, a pipe mixer and an orifice mixer. The complete information on behavior of the processes was obtained taking into account design and technological parameters of the abovementioned types of mixers. Computer simulation of flow in mixers of various types made it possible to substantially shorten time for conducting studies and confirm the results of field experiments presented earlier by the authors [11]. As a result of the analysis of the data obtained in the computer simulation of motion of the flow of waste water with the reagent solution, the following can be distinguished: when using different types of mixers, the best results of intensive flow mixing were obtained by using a mixer with a diaphragm of a special design and an orifice mixer. It is evidenced by the diagrams of distribution of pressure and velocities in these mixers. However, when using an orifice mixer, one can notice intensive mixing only at the center of the flow, and zones were noticeable at the walls of the pipeline in which there was practically no vortex formation and mixing respectively. In the pipe mixer, only a small region could be noticed in an immediate vicinity of the point of injection of the coagulant solution. Pressure and velocity vary in this region but these parameters change insignificantly in the main flow. The obtained hydrodynamic models indicate that the proposed diaphragm of a special design provides more efficient mixing of wastewater with the reagent. Models for pipe and orifice mixers have shown worse results. The proposed diaphragm enabled mixing of wastewater with the reagent as fully and quickly as possible.