Device Optimization And Experiment Study Based On Cyclone Collecting Eggshell Membranes And Eggshells

With the improvement of people's material life,the demand for eggs is increasing day by day.A large number of waste eggshells are produced in production and life that are difficult to be handled,which not only cause pollution to the environment but also are waste of resources.Many researchers are now concentrating on the research of eggshells and eggshell membranes separation equipment,but few are interested in collecting eggshells after separation from the egg membranes.Eggshells are rich in organic and inorganic calcium which are high quality calcium source additive,while eggshell membranes contain high quality mucopoly saccharides and proteins which can be used in many fields such as medical,chemical and sewage treatment.If the eggshells and eggshell membranes are separated and used separately,they will acquire more economic and practical value.In response to the above problems,through searching the current status of domestic and international collectting methods,the collecting method of the cyclone was proposed to achieve the research objective of collecting eggshells and eggshell membranes,and the key structure of the cyclone was optimized and the operating parameters were studied by experiment.(1)The data on the mixed mass ratio of eggshells to eggshell membranes,the size distributions of eggshells and eggshell membranes,the densities of eggshells and eggshell membranes and the floating speeds of eggshells and eggshell membranes were measured.The volume shape coefficient and equivalent diameter of eggshells and eggshell membranes were also acquired,and the energy loss coefficient and friction angle of the eggshells were measured to provide a theoretical basis for the design of the key structure of the cyclone,and to provide physical parameters for later numerical simulations to optimize cyclone by means of the physical properties of the eggshells and eggshell membranes.(2)Firstly,the overall structure of the cyclone device collecting eggshells and eggshell membranes was designed,and its operation principle and working process were introduced.When the production efficiency in a certain range,the outlet speed and outlet flow of the feeding device were calculated.Then the key structural parameters of cyclone separator were calculated and designed.The diameter of the straight section of the collecting cylinder was determined by calculating the minimum air flow required for the separation of eggshells and eggshell membranes.When the velocity range of the upper and under outlet was 2.5-15m/s,the diameter range of the upper and under outlet suitable for the separation of eggshells and eggshell membranes were obtained.Based on these,the rated power of sucting fan was calculated,and the selection of sucking fan was completed.(3)The principle of Fluent-EDEM coupling simulation and the mathematical model used in the process of numerical simulation were described in this article.The three-dimensional physical model of cyclone separator cylinder was established,the fluid field grid in the cylinder was divided,and the simulation process of cyclone separator cylinder was described.The separation cylinders with different upper and under outlet diameters were simulated numerically,the distribution of pressure and velocity in the separator cylinder was investigated.According to the number of eggshells and eggshell membranes captured on the outlet monitoring surface,the optimum diameters of upper and under outlets were determined.DPM trajectory tracking method was used to simulate,the effects of different height of straight section of the separating cylinder and cylinder top angle on the particle trajectories of eggshells and eggshell membranes in cyclone separator were investigated.The pressure and velocity distribution characteristics of the flow field in the separator cylinder were studied when the feeding machine and the sucking fan worked separately,which provided theoretical support for the operating parameters of the experiment.(4)According to the simulation results,the key structural parameters of the cyclone collecting cylinder were determined,and the design of the cyclone system and the installation of the test bed were completed.Orthogonal experiment was carried out with cylinder top angle,solid loading rate,pressure of sucking fan and speed of feed outlet as experiment factors,and the collecting rates of eggshells and eggshell membranes as evaluation indexes.The regression model between the recovery rates of eggshells and eggshell membranes and experiment factors was established,and the experiment parameters were optimized at last.It was found that when the solid loading rate was 1000 g/s,the cylinder top angle was 45°,the speed of feeding was 4.64m/s,and the negative pressure of sucking fan was 336.61 Pa,the recovery rate of eggshell membranes was 93.00%,and the recovery rate of eggshells was 97.89%,the collecting effect was the best.The results of verification experiment were similar to those of optimization,and the optimization results were credible.It provided a reference for the collecting technology of eggshells and eggshell membranes.