Structural Design Optimization And Flow Field Numerical Analysis Of Fluid Dynamic Dust Suppression Bulk Material Chute

In the process of transporting bulk materials such as grain,ore and cement in coastal ports,the shiploader is widely used.Due to the large height of drop caused by the depth of the ship’s cabin,the chute installed at the front of the arm frame of the shiploader is usually used to overcome the height of drop.The bulk material is broken due to the impact of the chute and the cabin,resulting in a large amount of dust.The dust moves with the induced wind formed by the bulk material to the external environment.At present,the port mainly uses high-pressure spray and high-power negative pressure fan to suppress dust,which consumes a lot of water,electricity and other consumable resources in this process.Therefore,it is very important to design a energy conservation and high efficiency dust suppression chute.In this paper,discrete element mehod and DEM-CFD coupling analysis method are used to study the methods of suppressing dust generation and dispersion,as well as accelerating dust deposition from many aspects,and a chute structure that can realize fluid dynamic dust suppression is designed.At the same time,it expands the application of key technologies of fluid dynamic dust suppression in new fields and promote green development.The main research contents of this paper are as follows:First of all,the structural design scheme of the fluid dynamic dust suppression chute is proposed.The discrete element method is used to analyze the influence of different structural parameters of single-stage chute and funnel buffer tank on the falling coal,and the law of coal velocity change is obtained.Through the simulation study of combined parameters,the reasonable structure that can control the velocity of coal and reduce the generation of dust is determined.Secondly,on the basis of determining the structural parameters of the dust suppression of the chute,the internal flow field of the chute is simulated by the DEM-CFD coupling method.The single variable method is used to analyze the effect of airflow backflow when the chute is fully expanded under the different number of reflux holes,the different distance between the reflux hole and the top of the single-stage chute and the different radius differences between the dust collecting hood and the chute.Then,the movement of dust particles in the dust collecting hood is studied by intercepting part of the dust collecting hood structure.On this basis,the structure of the coalescing blade is designed to make the particles turbulently coalesce and accelerate the agglomeration of fine dust particles.The population balance mode is used to study the internal flow field distribution and effect of dust agglomeration under different blade structure types and different blade spacing.The optimal coalescing blade structure is determined study through the combined parameter research.Finally,through the design of orthogonal test,the range and variance analysis are used to determine the optimal combination of structural parameters affecting the backflow effect,and the mass flow rate of airflow backflow under the combined parameters is obtained.An equal scale reduction model is established to carry out dust suppression test to verify the rationality of the design.