Bituminous Pavement Milling-planing Particles Clearing Vehicle's Dust Removal System's Design And Simulation

The recovery ratio of the commonly used large cold milling-planing machines never reaches 100%,although they have the function of recovering particles ,and there is a small amount of milling-planing particles and fine dust particles that would seriously affect the bonding strength between the newly paved bituminous material and the base surface formed after milling-planing left. In view of the existing problem, this paper presents a general scheme of milling-planing particles clearing vehicle, and determines the main performance and structure parameters of it. The basic working principle of the vehicle is nagtive gas-solid two-phase flow conveying, separating of gravity dust removal from wet spray. There are special equipments, such as assistant engine, fan, settling chamber, suction port, brushes on this vehicle.Aiming at physical characters of the milling-planing particles, including range of particle size, density change and the dressing of the dust, and the dynamic characteristics of mixed flow of gas-solid two-phase flow conveying, mainly studies on the combination of dedusting mode, and flow route design of the separating system to assure the dust removal efficiency, and eliminate the secondary pollution caused by the emission. And also, because of the big difference between particle size of the milling-planing particles of the bituminous pavement, wet spray is performed to improve the efficiency of agglomeration and capture. After a system simulation for the separation and settling progress of gas-solid two-phase flow in the settling chamber with FLUENT fluid mechanics simulation software, disadvantages of the original design of the settling chamber structure are clear, and then optimize the structure by simulating and correcting the settling and dust removal structure again and again to accelerate the settling speed of the solid particle in gas-solid two-phase flow and purify the exaust.Simultaneously, considering the two-phase flow speed is fast and initial velocity in the settling chamber is high, prolong the route of the gas flow to assure the dust removal efficiency.The results of the design calculation and simulation shows that the dust removed and separation system of the vehicle can complete the separation and settlement task of the bituminous pavement milling-planing particles efficiently,and has a more ideal cleaning effect to the fine dust that hardly be settled through spray agglomerating.