A Research On Carbon Monoxide Explosion Suppression Of The Venturi Tube In The OG System

The OG system is an equipment for wet flue gas purifying and recycling,which is widely used in converter steelmaking.In the operation of the system,the components of the gas that go through the venturi tube of the OG system not only have high temperatures,but also are combustible,therefore explosion could be occurred in the venturi tube.Based on Navier-Stokes equations of the fluid,coupled with burning velocity model of carbon monoxide and P1 radiation model,the method of numerical simulation was adopted to study the explosion characteristics such as burning,overpressure,mass and heat transfer of the venturi tube under different equivalent ratios.Results show that,starting spread section of the flame is located next to the nozzles when the flame has reached a relatively stable state,and it presents two different kinds of cyclical changes for pressure and velocity.The most easily to explode is at the diffuser,which followed by the throat section,and the reducing tube section the hardest;overpressure in reducing performances significantly,and the temperature in the divergent section increases obviously.The results of the simulation are consistent with the field explosion position of the bursting disc,which verifies the accuracy of simulation indirectly.According to carbon monoxide explosion characteristics of the venturi tube,the defects of jams and nonadjustable of the rice damper(RD)valve,the venturi tube had been optimized to a new structure which had a streamlined venturi tube combined with a streamlined heavy mound.A structure rationality was validated by the numerical simulation,and results show that the flow bypasses the two parts(cone and blunt tips)of the heavy mound affected by the induction of turbulent with an maximum error reaching 8.63% and the linearity error is below 4% at the other parts,suggesting that this innovation structure can effectively enhance the linearity control of the flow for a venturi tube,which not only reduces the risk of explosion but also improves the efficiency of dust removal.To discharge the accumulated energy of the explosion in time,a method for gas-liquid phase flow calculation was put forward to design the safety attachment of the venturi tube-bursting disc based on the assume of isentropic and abiabatic.Results show that when the quality is less than 0.1,compared with several other calculation methods,the method error is below 5.7%;When the quality is greater than 0.1,the method results are consistent with the experimental results,then the accuracy of the calculation method is verified.Compared with the classical models,this method is simple and accurate,and therefore it is convenient to be applied to industry.