| Iron oxide on the surface of the hot rolled plate roll will cause surface quality defects in cold rolling process and the subsequent handling, Now the mainstream technology of oxide descaling of hot-rolled steel is pickling. However, on the one hand, pickling process production equipment is not easy to seal, resulting in the acid gas diffuses to the whole workshop. Not only the plant, equipment suffer the corrosion severely, but the acid gas make worker pungent choking and the skin will be corroded, thus making working conditions very bad. On the other hand, due to the need to install acid recovery and regeneration unit, leading the process complex and cost increase. For this, after several years of research around the world, we found a new kind of steel surface descaling technology, i.e. high pressure mixed slurry descaling.High pressure abrasive slurry jet has a strong impact and grinding capability, and because of its low working pressure, high efficiency, non-pollution, this method get rapid development in recent decades. Now the pressure mixed slurry descaling equipment of cold rolling line in our country are all from foreign, we have yet to master the core technology.This paper focuses on the system research of high pressure mixed abrasive water jet for hot rolled coil or plat descaling. The main content includes:(1)Based on the basic theory of abrasive water jet and abrasive acceleration mechanism, and combined with the existing mixed way of high-pressure water and abrasive,by comparing the advantages and disadvantages of all kinds injection system of the abrasive jet system, we determine the overall scheme of high pressure mixed slurry descaling system, and at the same time design the high pressure water unit and the recycling system.(2)Simplify the nozzle model and to establish a two-dimensional jet flow field model in the GAMBIT software, based on two-phase flow theory, using the CFD software FLUENT to simulate the descaling spray process. After the flow field simulation of the parameters of jet angle, jet distance and abrasive volume fraction, analyze and compare the influence of the speed and pressure flow field of different parameters, by comparing the shock pressure on the steel plate to determine the optimal range of these parameters in descaling system.(3)Conduct the surface descaling experiment of steel plate by using high pressure water jet CNC processing equipment. Use the scanning electron microscopy(sem) to anlyze energy spectrum of the surface composition of the specimen after descaling. By comparing the oxygen content on the surface of the steel plate under different working conditions to judge the descaling effect whether good or not, thus summes up the descaling effect of different jet angle, jet distance and abrasive volume fraction, so as to choose the best parameters under which the descaling effect is completely. The experimental results and simulation results are basically identical. |
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