| 摘要 |
A pair of refractory plates includes a stationary bottom plate having a discharge opening and a movable plate having two discharge openings. The movable plate is mounted for sliding movement with respect to the bottom plate about a center of rotation between a center closed position and opposite open positions. The discharge openings of the movable and bottom plates are centered on a common circular arc centered about the center of rotation, and the discharge openings of the movable plate are positioned symmetrically on opposite sides of the discharge opening of the bottom plate in the closed position. The bottom plate has a second discharge opening at a position between the circular arc and the center of rotation. The discharge openings of the bottom plate are centered on a radial line extending from the center of rotation and intersecting the circular arc, such radial line corresponding to a radial center line between the discharge openings of the movable plate in the closed position. |
