Kneader Mixer Paddle Stress And Temperature Numerical Analysis

By5L kneading mixer as research object, CFD numerical simulation method was used to analysis solid propellant mixture flow field.And take computer as a tool the paddles stress and comparison were analyzed.Then get the pot wall pressure and temperature distribution, and provide a reference for the installation of the sensors in test system.Five independent parameters were selected to establish paddles, material pot diameter D, minimum clearance e, hollow paddle helix angle α2, and the angular velocity of two paddle ω1,ω2.and achieve the paddles parametric computer-aided design,and lay the foundation for the research work of the paddle.Secondly, by using computational fluid dynamics theory, determine boundary condition,the wall surface with the material slip-free, closed mixing flow field, downward acceleration of gravity,material viscosity and density and the mixed material non-mesh structure.And mixed material was meshed by non-structural.Again, take element analysis software as tools, flow field to be made transient simulation by dynamic grid method. Compile C language source code is applied to the complex boundary conditions, and complete numerical simulation of mixing process.Analysis and comparison the velocity field, pressure field, viscosity field, thereby determining the kneading mixer flow field numerical analysis and prediction methods.Then, through theoretical analysis and numerical simulation results show that:the paddles speed and shear stress presented proportional relationship,and mixed ability is powerful, but the higher requirements for paddles strength; In the mixing process, the viscosity increase with the material speed increased, and paddle shearing stress rose sharply when the viscosity exceeds certain value (600Pa.s in this case), while the flow rate is reduced, and stirring efficiency did not improve, instead of the higher strength requirements of the paddle;The higher solid component proportion,paddle shear stress is greater, the paddles occur stress and deformation, so the solid component is controlled a40%to75%.Based numerical simulation by changing paddle rotation direction and solid paddle phase: The pot wall pressure vary periodically,so the sensor in test system can be evenly distributed;When the blade is transferred, the material downward movement, pot stress increased focused on edges and center, when reversing, the material rolling up.Therefore intermittently change the blade rotation direction can improved mixing efficiency. The flow field temperature is done numerical simulation trough flow field pressure,and the results show that the temperature is higher near the flow field smallest gap, the paddle tip close to the bottom have the highest temperature, so at this part of paddles need higher capacity to resistance temperature deformation.Pot wall temperature distribution uniform, but at the pot bottom the high-temperature focus on edges and middle, so the test system temperature sensor should be located nearby the edge and center.