摘要 |
A porous ceramic structure adapted in a molten metal container in a way such that the structure pierces the wall of the container for introducing a gas thereinto. The structure comprises a main body made of a porous ceramic material and having a recession on the side adjacent to the outer surface of the container and a sub-body made of a porous ceramic material fitted in the recession of the main body. This ceramic structure enables the operator to make timely judgment for its replacement with new one before it breaks down to cause leakage of molten metal from its container. |