Energy Saving And Noise Reduction Of Flow Mixing Performance Intensified By Rigid-flexible Combination Impeller

When the fluid is mixed in the stirred reactor, the energy obtained by the impeller is mainly used for fluid rotation, internal transmission and consumption in the fluid mixed noise. Selecting suitable impeller type, reducing fluid mixed noise and improving energy utilization rate can intensify the mixing behavior of the fluid. In this work, themethod of experimental analysis and numerical simulation is used to research the rigid-flexible combination impeller about fluid mixing process flow solid coupling movement and noise reduction. In view of internal fluid flow and noise change, the rigid-flexible combination impeller is compared to the rigid impeller, concrete results are as follows.(1)The rigid-flexible combination impeller increased the interaction between the flow and the blade through its own fluctuation movement, so that the energy in a stirred tank could be distributed more uniformly, and strengthen the mixing behavior of fluid. The combination impeller improved the axial motion of the fluid, more fluid flew from the bottom to the top, so as to promote fluid mixing in the sink.(2)When the rotating speed was 210 rpm,under the action of rigid-flexible combination impeller,turbulence intensity of the over-blade area and the bottom increased more significantly, in addition the fluid turbulent kinetic energy distribution was more uniform which was conducive to the dissipation of energy at the blade tip. The rigid-flexible combination impeller could more effectively transfer the energy from the blade tip to the fluid and reduce the agitating tank "dead zone", and help the efficient use of energy in the fluid mixing process.(3)Macro instability frequency was calculated in the experiment to indicate the movement complexity of micro fluid, and flow field visualization technology was used to conduct the effect of fluid mixing. When rotate speed N got 90 RPM, the macroeconomic intability frequency of firm-soft combination impeller reactor appeared 50.5% higher than the rigid impeller, while mixing time reduced by 46.5%.(4)Stirred tank and the agitator is the main source of noise, meanwhile, the distribution of the noise of the agitator is symmetry at the center of the stirring shaft as the center of the state, and from the stirring shaft to the stirred tank, the noise attenuation trended.In the same location of the signal. With the same conditions, firm-soft combination impeller by different frequencies to answer the pressure level was lower than the rigid blade.In the mixing of fluid, the rigid-flexible combination impeller can improve energy utilization rate and decrease noiseconsumption, resulting in reducing the fluid noise. In the end, the rigid flexible impeller combination achieve noise reduction and energy saving.(5)Simulation and experimental results showed that compared with the traditional rigid paddle stirred reactor, firm-soft combination impeller reactor will be energy-saving and noise-reducing.