Research On The Dustpan Character Of Dustpan Dredger

With the the vigorous development of domestic and international dredging markets,especially the dredger’s development of large-scale, multi-functional, intelligent, domestic andforeign scholars are paying more attention to dredge. Dustpan dredger is a new type of dredgerfollowing cutter suction dredger and drag-suction dredger etc, and it has attracted more andmore attention with its many advantages such as broad dig groove, flat groove, wideapplicability etc. Compared to other types of dredger, the main differences are the dustpan typeand the way of soil-breaking. The dustpan dredger relies on the impact of high-pressure waterjet to break the soil, while conventional dredgers mainly rely on mechanical action. At present,domestic researches on the dustpan dredger are rarely, as a result, mainly research are made byreferring foreign dustpan. Based on the project of Heixiazi island waterway dredging, thecharacteristics of dustpan dredger is analyzed in this paper.The main content of this paper includes: the development of dredging markets anddredgers;based on the hydraulic transport of solid materials theory, design principle of dustpanis put forward. Based on theory and calculation method of fluid dynamics, the type ofmultiphase-flow model is setup. The change of flow field and inlet/outlet velocity is analyzedthrough numerical simulation of different types of dustpan’s flow field to determine theoptimal one.The effect of working coefficient including the mud concentration and particle sizeon sucking efficiency and velocity distribution near the inlet is studied by numerical simulation.The experimental system is built and mud concentration from pipe is measured. The value iscompared with the simulation result to validate its accuracy, which is further more to determinewhether the dustpan meets the actual needs or not.Research in this thesis mainly draws the following conclusions(1) Flat square mouth typeof dusupant has many advantages,and should be the preferential plan. Multi-body dustpan typehas a significant performance on increasing the dredging width and preventing thesedimentation of sand;(2)comprehensive ansysis of pressure distribution and import/outportspeed among three types of dustpan based on flat square mouth,determine type3is the optimalone;(3)Both mud concentration and particle size are factors of suction efficiency,but thedominant factor is mud concentration: with the increase of mud concentration, the velocity ofinlet and outlet will decrease.If the mud concentration is too low, the velocity will increase,but compared to the overall speed,the increased velocity’s effect is little, and the total amount ofdredging will reduce in unit time;If the mud concentration is too high, the sludge pressure ofmud pump will increase,and it will consume mud pump’s kinetic energy and reduce totaloutput of the earthwork.(4) The numerical simulation results of dustpan1:8model is consistentwith experiment data,and the mud concentration measured in experiment is high enough tomeet the actual needs.