APPARATUS FOR THE DETECTION AND MEASUREMENT OF PARTICULATES IN MOLTEN METAL

摘要

A probe (10) for insertion into molten metal to detect and measure particulates suspended therein includes an inner tube (16) of an electrically insulated material forming a metal receiving chamber (15), the tube having an orifice (17) to permit molten metal to flow into the chamber. A first electrode (22, 24) extends into the chamber for engaging metal within the chamber and a second electrode (26) surrounds at least a portion of the inner tube for engaging molten metal outside of the chamber. The electrodes may be connected to a measurement device (48) for establishing a current path through the electrodes and passing through the orifice for measuring changes in the electrical potential produced by the passage of particulates entrained in the molten metal passing through the orifice. An outer sheath (30) of heat resistant material surrounds a portion of the second electrode and a gas passageway (22) extends out of the inner tube for connecting to a vacuum source (44) to create a pressure differential within the chamber for facilitating the flow of molten metal through the orifice. A liquidus depressing material (50) is in the chamber for alloying with molten metal entering the chamber to lower the liquidus temperature of the molten metal and permit a longer time period for detecting and measuring particulates in the molten metal.