| 摘要 |
Refractory parts for valve closures include members which by mutual sliding or rotary action, interrupt the flow of molten metal from a metallurgical vessel. Closed reservoirs filled with an impregnation agent, for example tar, pitch, methane gas, are provided embedded in the refractory parts and disposed adjacent to refractory wearing surfaces which are susceptible to undergo depletion and wear. The impregnation agent, on being heated by molten metal, slowly releases hydrocarbons which percolate through the refractory pores to the refractory wearing surfaces to prevent premature wear to the refractory surface and to provide lubrication for the flow of molten material in contact with the refractory wearing surfaces. The impregnation agent can be replenished in the form of replaceable porous cartridges which can be inserted into the reservoirs. Alternatively, the reservoirs can be filled with refurbishing supplies of the impregnating agent through an external nipple or a charging lock which communicates with the embedded reservoirs. |
