摘要 |
A windbreak provided along a side of a tray prevents insulators located close to an entrance of a furnace from being directly cooled by the air coming into the furnace. All of the insulators mounted on the tray can be uniformly cooled when conveyed out of the furnace after finishing a sintering operation. A resistance value of the electric resistor in an insulator located close to the entrance is substantially equalized with a resistance value of the electric resistor in another insulator located far from the entrance. |