| 摘要 |
A valve construction particularly for closing the connection of a charging hopper to the furnace throat of a blast furnace comprises a valve seat for the hopper which is arranged in a recess portion or out of the stream of the material to be poured therefrom into the furnace. A valve closure member includes an inner portion having a cross section which makes it more flexible than an outer thicker portion. The outer sealing rim is formed in the thickened outer portion and it is rounded. The valve seat defined at the lower end of the charging hopper advantageously includes an annular groove which is connected to a source of gas under pressure and the groove is located over the rounded sealing rim of the valve member. Gas under pressure is directed to and through the groove and blows against the sealing rim of the valve member to provide the double function of preventing escape of gases from the furnace and cleaning the seat of the valve member for proper sealing purposes. |
