Study Of Material Behavior On Air Leakage Of Cinder Valve

In recent years,environmental pollution has become increasingly serious.Harmful gase,liquid and waste discharged from steel industry have increased the burden of environmental protection.In response to the national green policy of energy conservation and emission reduction,steel industry is facing some problems such as the reform of production management,the innovation of production technology and the improvement of production equipment.As the basic production department of steel industry,the sintering department is mainly responsible for sintering and forming of hematite.Sintering machine,the main sintering production equipment,has a lot of air leakage problems in the working process.Because of air leakage,the fuel in sintering raw material can not be fully burned and produces a lot of black smoke,which not only seriously pollutes the environment,but also greatly reduces the quality of sinter.Cinder valve,a device for discharging crushed sinter at the bottom of sintering machine,exists 4% air leakage rate.In the working process,air leakage occurs due to blanking wear and aging of sealing rubber strip.Therefore,it is of great significance to study the air leakage of cinder valve for sintering machine.This paper analyzed the air leakage problem of a new type magnetic sealed cinder valve for sintering machine,including the wear of the cinder valve caused by blanking sinter and the distribution of ferromagnetic medium around the valve plate.The air leakage problem of the cinder valve was analyzed respectively by macroscopic observation,microscopic characterization and finite element simulation.The results of blanking scanning and wear numerical simulation of blaking sinter show that macroscopically,the wear of blanking sinter to the cinder valve is attributed to the abrasive wear and impact wear,and microscopically,it is the collective effect of impact shear and micro-cutting of sinter to valve plate.During the wear process,large sinter continuously impacts the material surface,which results in lattice deformation,slip dislocation and multiplication until the debris drop from the material surface.In addition,there is always a stress concentration near the blanking point,which make the next blanking wear easier.Distribution of ferromagnetic medium in the magnetic field around different cinder valve plates shows that due to magnetic repulsion,the magnetic field strength of square cinder valve is weak at the same polar angle,and the distribution of magnetic medium is sparse and porous,which is easy to air leakage.Compared with the square cinder valve,the round cinder valve does not have magnetic repulsion at the angle,which makes the magnetic field strength and the magnetic medium distribution more stable and uniform.The fluid simulation of ferromagnetic medium during the opening process of valve plate shows that the magnetic medium mainly changes from isomagnetic potential state to non-equal magnetic potential state under the action of magnetic field.The moving speed of the magnetic medium is gradually decreasing,and finally it is in a "half pear shape" state..The shape of magnetic medium changes from the initial "convex top and concave bottom" to the "concave top and convex bottom",and the sealing property gradually disappears,while the opening of valve plate has no effect on the distribution of magnetic field.