Reducing the erosion rate of the Purging plug and increasing the furnace age of the re-blowing converter is an important research topic in the re-blowing technology.
In this test, natural salt bricks are used to simulate the material of Purging plug, water is used to simulate molten steel, and injection holes of different diameters are used to conduct injection tests under different pressure and flow conditions, and the erosion data of injection holes are measured after each injection. The corrosion damage of the vented bricks under different injection conditions can be obtained.
(1) The axial erosion velocity and radial erosion velocity of the nozzle holes of the Purging plug, increase with the increase of the bottom blowing air supply flow. The design of the Purging plug, should prevent the two nozzle holes from overlapping too much in the direction of the erosion zone.
(2) The large erosion angle (about 80°) at the upper part of the nozzle hole of the Purging plug is caused by the upward suction of the bottom blowing airflow and the formation of a horizontal circulation at the outlet of the nozzle hole of the Purging plug. The erosion angle is little affected by the diameter of the orifice and the gas flow.
(3) The erosion of the lower part of the orifice is mainly caused by the water leaking down the wall of the orifice and dissolving the wall of the orifice. The erosion angle is about 10°, which is similar to the expansion angle of the airflow, and is little affected by the diameter of the nozzle hole and the flow rate of the bottom blowing gas.
(4) The use of nozzle holes with a smaller diameter can enhance the stirring effect of the bottom blowing gas on the molten pool, but it is necessary to increase the gas source pressure for the re-blowing, which should be paid attention to in the construction of domestic converters or equipment renovation.
