Simulation of In-Flight Reduction of the Fine Iron Ore Concentrate by Hydrogen

A mathematical model has been proposed to simulate a novel method for direct reduction of iron concentrate by hydrogen. Flight of fine particles in a vertical reactor containing a gaseous mixture of H2-N2-H2O has been studied. Effect of generating gaseous jet on the residence time of the particles has been also investigated. Coupled turbulent Navier-Stokes equations with eddy kinetic energy equation have been solved using a developed homemade code. Kinetics of this reaction has been studied using the unreacted core model. Accuracy of the model predictions has been approved by the experimental data. Finally, effects of vital variables (i. e. temperature, particle size, hydrogen concentration and particle feed rate) on the particle residence time and also fractional conversion have been studied.

The Effect of Particle Feed Rate on the Plastic Media Blast Jet

Paint removal from military aircraft is often done by plastic media blasting (PMB): the use of plastic grit in a conventional blast jet. However, there is some concern that PMB will cause damage. To help in evaluating this possibility, a “time of flight” meter is used to measure particle velocity in the jet, as a function of air pressure, distance from the nozzle, and particle feed rate, F. Using the data and a momentum balance, a semi-empirical model relating these variables is developed and used for analysis of the effect of F on the intensity of kinetic energy delivery, E, to a work piece. The analysis shows that F has several important effects on E. These methods and results will be useful for damage studies and in production work.