Design Optimization And Simulation Analysis On Pneumatic System On Vacuum Sweeper

The vacuum sweeper is a highly efficient de-dusting vehicle combined with the functions of dust-sucking, separation and transportation developed after the road cleaning vehicle and the sucking & sweeping vehicle. It consists of a sucking system, a primary dust box, a secondary dust box, a dust recovery system and a traveling system etc.As the most important two key parts in the pneumatic system on the vacuum sweeper, the style of construction and separation efficiency of the sucking mouth and gravity settling chamber make decisive effects.This paper pay high attention to study the pneumatic system on the vacuum sweeper, Combine the methods of manufacture a factual modeling and computational fluid dynamics to study the sucking mouth and gravity settling chamber of the vacuum sweeper'pneumatic system.It analyse their flow field analysis and optimization construction.At first made a modeling through the three-dimension software and design the first scheme and then enter the CFD to study the flow field analysis.Un-struction meshes were used to generate grids and the k-εmodel was used to simulate the turbulent flow.Through the simulation analysis of the beginning design scheme,it indicates uneven floe field caused by unreasonable structure reduces the dust suction efficiency.At last according to the result of the analysis to improve on the cheme till we obtained the perfect flow field distribution and design scheme.This paper mainly covers the following two aspects:1> Design of and analysis on the sucking system:This paper aims at the study at the following three aspects for the sucking mouth:First, it is to analyze the force conditions and initial moving process of dust particles subject to air stream, to make clear the function relation of the air velocity to cause the dust particles to move with the dust size and density; Second, it is to work out the formula for calculating the local pressure loss inside the sucking hole by way of simplifying the structure of the sucking hole, and propose a design optimization method for minimizing the local pressure loss inside the sucking hole; Third, it is to carry out simulation analysis on the flow fields inside sucking holes of different structures with the CFD technology, to execute preliminary performance assessment, and make judgment on the rationality of the optimization solution.2> Design of and analysis on the de-dusting system:This paper aims at the study at the following three aspects for the gravity settling chamber:First, it is to analyze the settling mechanism of dust particles in the settling process and in laminar flow, and propose a critical settling formula for the design of the gravity settling chamber; Second, it is to analyze the characters and impact factors for the design of the gravity settling chamber on the vacuum sweeper, and to propose a sizing method for the gravity settling chamber; Third, it is to execute simulation analysis on the flow filed inside the gravity settling chamber with the CFD technology, to find out the irrational structure and propose an improvement solution, with the purpose to lower the bottom air velocity, improve the separation efficiency of the dust particles in the gravity settling chamber, and meet the design requirements.