| 摘要 |
PROBLEM TO BE SOLVED: To provide an instrument for measuring the height of steel bath in a vacuum-degassing apparatus with which height of the surface on the molten steel is directly measured in a non-contact manner, measuring accuracy is improved, and the height of the steel bath can precisely be grasped, while protecting the measuring instruments from the heat of the molten steel. SOLUTION: A transmitting part 8 where electromagnetic wave of microwave etc. can be passed through is arranged at the upper part of a vacuum vessel 2, and a measuring means 20 constituted of a microwave level-meter is arranged at the upper part of the transmitting part 8, and a heat-preventive plate 18 having an opening part A between the transmitting part 8 and the molten steel 6 and controlling the number of rotations with a control means 30, is provided. During degassing-treatment to the molten steel 6, the heat-preventive plate 18 is rotated with a first number of rotations and only during measuring the height of the surface of the molten steel 6, the microwave W1 sent from a transceiver part 22 is passed through the transmitting part 8 and the opening hole part A and reflected in the surface of the molten steel 6. Then, the heat-preventive plate 18 is rotated with a second number of rotations at lower than the first number of rotations so that the reflected microwave W2 is passed through the opening part A and the transmitting part 8 and received by the transceiver part 22. COPYRIGHT: (C)2006,JPO&NCIPI |
