Key Technologies Of All Wet And Dry Suction Sweeper

Wet and dry suction sweeper is a sanitational equipment of negative pressure vacuum,gravity sedimentational separation and garbage transport, widely used in the sweeping oftrunk roads, airports, urban residential areas, parks and roads. Wet and dry suction sweepercan be divided into wet dust removal method and dry dust removal method. Dry dustremoval method doesn’t need water system and regardless of the weather temperature limits.Wet dust removal method has good environmental performance and can prevent the dustinto the atmosphere.The main working medium of pneumatic system is air and work object is dust waste onthe ground in wet and dry suction sweeper. The working principle is: centrifugal fangenerates negative pressure in the mouth of combined nozzle, while the back chamber ofcombined nozzle exhausts closed air curtain through slit vents. With the joint action on theground, the dust particles are sucked from the suction port and piped into gravity settlingchamber and cyclone separators through the exhaust for dust filter. Clean air is dischargeddirectly into the atmosphere, completing the function of wet and dry suction sweepers.Structure of the combined nozzle determines the form of flow field inside the suction,and impacts on cleaning efficiency of the combined nozzle. The design theory of combinednozzle mainly related to dust dynamics, design calculations of closed air curtain and airconvergence. On the basis of related theory and design principles of combined nozzle, thepaper analyzes structural parameters of the exhaust port area S, nozzle length L, nozzlewidth B, nozzle height H, nozzle contraction angle α, tilt angle β of the dust tube and withthe objective of local pressure loss minimization in suction of combined nozzle, optimizesthe related design structural parameters of suction in combined nozzle. In the establishmentof combined nozzle and ordinary pure suction nozzle, based on the use of fluid simulationsoftware Fluent to their respective numerical simulation and performance analysis, the paperconcludes that: a slit air curtain nozzle has a better effect on dust particles on the ground andalso farther control range.Gravity settling is generally used as the first stage of dust removal for wet and drysuction sweeper. With the analysis of dust remove mechanism of gravity settling chamber,the paper gets the basic principles of structural design and performance indicators. Internalbaffle style in gravity settling chamber can extend the air traffic of dust particles in gravity settling chamber and change the direction. Therefore, the form of baffle has great impact ongravity settling chamber removal efficiency. Based on computational fluid dynamics CFD,the paper analyses internal flow field of gravity settling chamber under two differentphysical models of baffle forms to get the best gravity settling chamber design programs.