To prevent the leakage wind through gaps between joint edges when the shape of the joint edges are changed by attaching the joint edge surfaces of neighboring palettes with liners provided with either of labyrinth shaped recessed part or protruding part and by forming the palette joint surface with labyrinth seal by mating each recessed surface and protruding surface of both liners.

Edge surface liners 1 comprise a pair of liners 1c and 1d, one of which is formed with a protruding part at the center of the joint surface and the other of which is formed with a recessed part at the center of the joint surface and by mating both liners 1c and 1d, a pair of expansion chambers 11b are formed on the joint surfaces. The gas flow from a high pressure side (outside of the palette) to a low pressure side (inside of the palette) is decompressed by passing through narrow gaps and expansion chambers 11b and leakage wind is prevented. Therefore, if the shape of the edge surface liners 1 is changed by thermal stress and impact stress caused by the sintering step of sintered ore, the leakage wind preventive function of edge surface liner 1 will not be impaired thanks to such labyrinth structure.