Hollow Blade Paddle Dryer Of Sludge Optlmization Design

Sludge garbage of China,as an important part of second waste coming from urban sewage,has a huge annual production.Sludge drying is a widely used way to handle sludge.Hollow paddle dryer is a kind of widely used drying equipment,but existing machine design is all based on engineering experience,and there is no designing materials of paddle dryers and guidance of experimental study at home.From the perspective of different materials characteristics,there is no related study on whether different stirring speeds,different structures of blades have an effect on drying rate.However,if drying the sludge mindlessly,it certainly will cause a waste of energy and money,for the drying rate is directly related to the utilization ratio of energy.Based on characteristics of sludge,the researcher chose and designed paddle dryer.However,in practical application,the researcher found that main problems were wall sticking and material accumulation.Combining theoretical knowledge of fluid mechanics,the researcher performed stimulation and analyzed statistics on the internal flow field with Fluent Software,which provided a valid basis for later use and design.Details are as follows:1.The drying materials this thesis chose was from the sludge of Tianjin Binhai New Area Sewage Treatment Plant.The initial moisture content of the sludge is 85%,and final moisture content is 35%.With the calculation of heat balance and material balance,the drying square was decided.Then the researcher preestimated the square of paddle dryer,determined sizes of all parts,and chose transmission structures,design the structure of sludge drying machine.Under those preparations,the researcher did a solid modeling on dryer with SolidWorks.2.With SolidWorks,the researcher simplified the model,and built a dynamic-static fluid model with Workbench-Design Modeler,and optimize the finite element model of the grid,set the boundary conditions.After that,based on theoretical knowledge of fluid mechanics,the researcher selected RNG k-? turbulent model based on pressure solving device and sliding mesh method,simulated internal flow field with fluid analysis software Fluent,and analyzed materials' temperature,distribution of speed and turbulent kinetic energy as well as sizes of torque under different mixing speeds,different material stick degrees and wedged gaps of different paddles.3.In material viscosity,stirring speed,blade angle of the wedge angle of the wedge factor paddle design variables,With the size of power and turbulent kinetic energy as the optimization goal,this research explored the influence that every factor had on energy consumption and fluid field with orthogonal experiment and range method,and obtained optimal dryer parameters through the data analysis.4.Through this thesis's design and simulation analysis,the researcher hoped to provide some reference for the future design and use of paddle dryer.