| The corrugated plate is a kind of steel plate coated with zinc after hot-dip galvanizing treatment,which has strong corrosion resistance,good appearance and low cost.However,in the actual production process of a steel pipe plant,it comes out of the galvanized bath with impurities such as zinc slag and zinc particles on its surface.After being purged by the purging device of outer blowing ring,there are still remain many residues on it,which seriously affects its corrosion resistance and service life.The high-speed gas is sprayed through the ring nozzle onto the surface of the corrugated plate to complete the external blowing operation.The ring nozzle acts as a key part of the outer blown ring purging device,and its structural parameters play an important role in blowing off the surface impurities of the corrugated plate.Therefore,combining with the project of "Research on Outer Blowing Ring in Hot Galvanizing Workshop of a Steel Pipe Co.,Ltd.",the following research has been done:Firstly,the outer blowing principle of the purging device was analyzed,and it was founded that the impurity blowing operation of the corrugated plate surface is mainly completed at the air outlet of the ring nozzle.Using CFD method and Realizable k-? turbulence model that does the best simulation to this type of impinging jet,numerical simulation has been done to flow field of the annular nozzle in original structure.And it was analyzed that when the corrugated plate entered the ring-shaped nozzle,the velocity and pressure distribution of the turbulent flow on the surface of the plate along the horizontal direction of the corrugated plate movement.Secondly,the original structure of the ring nozzle was improved.The effects of the outlet width of the annular nozzle,the inclination angle of the outlet and the diameter of the inlet on the airflow velocity distribution and pressure distribution on the surface of the corrugated plate under different working conditions,which were discussed.The influence of the positive and tangential forces on the surface of the corrugated plate was analyzed.The results showed that comprehensively considering distribution of velocity and stress on the plate surface,the optimum structure of a ring nozzle should have a gas outlet width of 1.2 mm,an air outlet inclination angle of 40°,and an air inlet diameter of 33 mm.The flow field analysis of the improved ring nozzle was carried out.This paper also studied the velocity distribution and pressure distribution of impinging jet on the moving corrugated plate through the ring nozzle.Finally,the CFD-EDEM coupling simulation method was used to simulate and analyze the improved ring nozzle and the original ring nozzle blowing particles of different diameters.The results showed that when the inlet pressure of the ring nozzle is 0.3 MPa,for particles with diameter less than 1 mm,the improved blowing efficiency of the ring nozzle is 100%,and that of the original ring nozzle is 98.9%.When the particle diameter increased to 3 mm,the removal efficiency of the improved ring-shaped nozzle is 71.7%,and that of the original ring-shaped nozzle is 59.4%.As the particle diameter increases,the blown efficiency of the ring nozzle gradually decreases.By increasing the pressure at the inlet of the ring nozzle,it was found that when the pressure at the inlet is 0.4 MPa,the blowing efficiency for particles with a diameter of 3 mm is 85.6%.When the inlet pressure increases to 0.5 Mpa,the removal efficiency of particles with a diameter of 3 mm is 92.0%. |
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