In this paper studied the momentum, heat and mass transfer of a flow of gases coming from the process into a Peirce-Smith converter. This flow is captured by a primary and secondary hood type side gate. The flow regimen inside both hoods is turbulent. The simulation of the system was solved using k-ϵ model. Metallurgical gases into the converter, rich in SO2, reach very high temperatures, which should be captured by both hoods, which are in charge of first cooling step with the help of the ambient air, by which a mixture model is contemplated for the SO2 and N2 gases. Simulation delivered velocity, pressure, temperature and concentration profiles. From these results it is possible to determine the average values into the two hoods, resulting in an average velocity of 11.4 and 3.6 m/s inside of the primary and secondary hood respectively, identifying the area of leak in the floodgate of the primary hood. The average temperature at which SO2 gases occur is approximately 1200 °C which ascend and cool to come into contact with the flow that enters the secondary hood with a temperature of 20° C, reaching an output average temperature of 640° C. The highest concentration of SO2 is produced inside the converter, reaching a value of 1.155 mol/m3.