| In this paper, a physical model of anaerobic tank section has been established in A2/O treatment process of a sewage treatment plant. The numerical simulation and experimental methods were carried out for systematic study. In the numerical simulation, the structure of the mixing tank and agitator was analyzied objectively.By the use of GAMBIT the geometric model of mixing tank and agitator sized of prototype were established. With the help of the k-ε standard model, solid-liquid two-phase flow model in FLUENT fluid calculation software, the flow field of mixing suspension state has been studied. The main work content is to optimize the form of installation design under the same border and other cases geometric conditions:different levels of inclination (30°,45°,60°), different placed depth (0.97m and1.47m from the bottom of tank to the center of agitator) and different pitch angle(0°,35°). Through the contrast of the flow velocity cloud between the actual program and improvement program, a optimization of installation form can be found out.The model experimental method was applied in this paper, and the walnut shell filter, iron hydroxide powder and kaolin were taken as experimental materials. The mixing efficiency can be determined by detecting the value of turbidity at the outlet in different scenarios. The main experimental work includes:(1) the experimental determination of the different installation program, from inclination, placed depth and pitch angle three different aspects, to get a optimization of installation form, which can be compared and analyzed with the simulation results;(2) the study of hydraulic characteristics of the mixing flow field by changing the running conditions of mixer, from the parameters of rotation speed and frequency, sweeping angle and the draft tube three experimental options, to analyzed the effect of frequency control and sweeping method on the degree of mixing, where the corresponding energy-saving programs might be obtained. |
PDF Full Text Request