Design And Analysis Of Dust Removal System For Sweeper Based On Gas-solid Coupling

Road sweeper is a special vehicle that integrates the functions of garbage cleaning,collection and transportation,it has the advantages of high working efficiency,less secondary dust and energy saving and environmental protection.The dust removal system is the key executive system of road sweeper,and its design level determines the working efficiency of the sweeper.In this paper,the dust removal system of a small suction and sweep sweeper is taken as the research object,and its cleaning efficiency is studied by computational fluid dynamics(CFD)method,and an improved design scheme of suction nozzle and fan structure is proposed.The main work of this study is as follows:1)Study on boundary conditions of cleaning mechanism.Based on the working environment of the small suction and sweep sweeper,the main components of the working object of the cleaning mechanism are studied.Based on the motion mechanism of dust particles starting,suspending and settling,the interaction between dust particles and airflow is studied.The kinematics process of dust particles being sucked and transported to the dust collecting box is studied.On this basis,the boundary conditions of the cleaning mechanism are set as the basis of subsequent simulation analysis.2)The influence analysis on key structural parameters of suction nozzle on cleaning efficiency.Parametric modeling and CFD method are used to numerically simulate the internal flow field of the original nozzle model.The influences of key structural parameters,such as radian Angle α at joints,height H of nozzles and ground clearance δ,on the performance indexes such as pressure field,velocity field and velocity vector are evaluated.The results show that the radian Angle α at the joint and the height of the suction nozzle H have significant effects on the negative pressure at the shoulder,the negative pressure at the inlet and the average velocity at the inlet.The selection of reasonable structural parameters can reduce the eddy current area at the shoulder and increase the negative pressure and velocity at the inlet.When the ground clearance is δ=10mm,the suction nozzle will obtain the ideal effect of dust collection.3)The influence analysis on structural parameters of the fan impeller on the working performance of the fan.The basic theory and governing equations of gas-solid two-phase flow are introduced,and the main parameters such as flow rate,pressure,efficiency and speed are studied to evaluate the performance of the fan.The influence of blade profile,blade structure,blade length,blade number and other parameters on the pressure field and velocity field inside the fan is evaluated.The working performance of the fan is evaluated based on the factors of pressure,flow and inlet and outlet speed.In view of the complex working environment of the sweeper,the influence of different rotating speeds on the working performance of the blower is analyzed.The results show that compared with the original impeller structure,the outlet flow of the improved impeller structure increases by 10.8%,the outlet speed increases by 11.4%,the wind pressure increases by 18.2%,and the working performance of the improved impeller structure is improved obviously.4)Test of cleaning efficiency.Based on the prototype,the reliability of the numerical simulation analysis is verified.The field test was carried out according to the industry standard QC/T 51-2006 road sweeper.The results show that the cleaning performance of the improved sample vehicle reaches the expectation and meets the design requirements.In this study,the simulation,design,improvement and test of the dust removal system of the small cleaning vehicle were carried out,which can provide a strong reference value for the design and development of the clean sanitation vehicle.