Simulation And Optimization Design Of The Mixing Process Of Granular Alkali Metal Alkoxide Reactor

Alkali metal alkoxide is an important chemical engineering product,which is an important raw material of synthesizing amino acid protective agent and peptide drugs.As is known,the common method of factories to produce powdery alkali metal alkoxide is method of medal which may lose easily during the process of production,storage,transportation and use.It also causes safety problems.Through cooperation with Changzhou Jien Pharmaceutical Co.Ltd,the technology of method of metal was improved.In this project,tank reactor was chosen as the equipment to produce granular alkali metal alkoxide and realized the industrial production successfully.There still existed many problems in the production of granular alkali metal alkoxide.1)A certain powdery alkali metal alkoxide existed in the finished products,affecting the quality of the products.2)The reactor has high power consumption and low efficiency.To solve problems above,The production of granular potassium 2-methyl-2-butoxide was chosen as research subject in this essay.According to the analysis of production process and the production equipment,it was found that the liquid-solid two-phase coexisting phenomenon existed in the system because of the formation of powdered potassium 2-methyl-2-butoxide in the later stage reaction.The phenomenon not only affected the quality of crystallization,but also affected the power consumption of stirring reactor.Therefore,it is necessary to promote secondary dissolution by intensive stirring.The mixing effect of stirring is not only closely related to structure of stir paddle,but also affected by other factors such as rotation speed of stir paddle,components stirred tank,and the temperature in the tank.In this essay,numerical simulation method was used to simulate and optimize components of equipment and factors of technology.Then the results was verified by small-scale test and factory production,realize the secondary dissolution of powder products,and finally production efficiency was improved.Firstly,multiple reference frame and Euler-Euler multiphase model were used to run numerical simulation of solid-liquid two-phase in the tank.The mixing effect of different paddles was analyzed.The paddles contain six-bend blade open turbine agitating paddle,the parabolic disk turbine agitating paddles,six straight blades open the turbine.On the basis of above work,two kinds of new paddles named SG-6(1)and SG-6(2)were designed.Though the comprehensive analysis of flow field,solid phase volume distribution as well as solid phase suspension uniformity,the test effect of SG-6(2)was much better.Furtherly,the impact of inner baffles of tank on mixing effect was researched.Via analysis of turbulent distribution and stirring power consumption,the installation form of the angle between the baffle and the wall of the kettle was determined to be 0=90°.The SG-6(2)stir paddle and 0=90° baffle was determined to be the best structure.On the basis of stirred tank with above structure,technology factors such as operation temperature and rotation speed were simulated and optimized.The results showed that when the inner temperature of the tank was kept 160? and the rotation speed was kept 140 r/min,a better stir effect could be achieved in a relative low unit volume power.According to the results of simulation calculation,a new stirred tank was designed and a laboratory experiment was conducted on the secondary dissolution of powdered potassium 2-methyl-2-butoxide.Meanwhile,the mixing effects of solid-liquid two-phase during the tests were examined by self-made new multi-phase flow picture recognition system software.The results showed that under circumstance of the structure combined of SG-6(2)paddle and 0=90° baffle,operation temperature of 160?165?,rotation speed of 150?155 r/min and mixing 30 min,the best stir effect was achieved which was also in accordance with simulation results.According to the results of simulation and laboratory experiment,the industrial device was designed under the circumstances of the amplification effect.The results showed that using the device structure and operation process above,the powder product realized the second dissolution.In the final products,the average size of granular potassium 2-methyl-2-butoxide achieved 0.7 mm,and the overall production time was reduced by 20%and the overall power consumption was reduced by 15%.In this paper,equipment process and technology of alkali metal alkoxide production were optimized through the method of combination of flow field simulation and experiment,which improved the production efficiency and product quality of granular potassium tert-amyl alcohol,and provided a new thought for the optimization of related chemical engineering equipment and technology.