The Study And Numerical Simulation Of Mixing Unit In Modified Starch Dry Processing By Turbine Technology

At present, mixing unit is a very important restricted facter in modified starch dry processing. Turbine technology bring new means for the modified starch dry technics. This paper is the research of turbine technology in mixing unit in modified starch dry technics. With the development of computer technolory, CFD techgnology provide a scientific way to study mixing. It is confirmed, mixing ratio is the most important index for scaling the mixing effect, and it also is one of the key parameters in the mixer design. Only a few studies were carried out on the numerical simulation of mixing process by using computational fluid dynamics (CFD). In this paper, we study the turbine mixer synchronously by using CFD package FLUENT6.1 and SAS9.0. We adopt the multi-reference frame (MRF) and RNG k—ε turbulent model to solve the velocity and chroma fields respectively in the simulation. We adopt deferent vane fixing angle, the number of vane and the axial propelling speed, to design three factors in five levels optimize numerical simulate experiments, and the total number of the experiments is 23. And we analyze the results by SAS9.0, we get the correlative curve and the optimize design project. The key results are: vane fixing angle is 22.5°, the total vane in the 2 meter-long mixer is 51, and the axial speed is 1313.6rpm. Adopt the optimize parameter, we do the numerical simulation experiment again, and the mixing ratio is above 99%. It totally answers to the mixing demand in the modified starch dry processing. The results are of importance to the optimum of industry stirred reactors and to the turbine mixer in the future. With the rapid development of computer and the grown up of CFD technology, the research means is very promising in researching undiscovered or new pattern fluid equipments.