[机] Durville pouring, Durville process

dù wéi lì qīng zhuǎn jiāo zhù fǎ ㄉㄨˋ ㄨㄟˊ ㄌㄧˋ ㄑㄧㄥ ㄓㄨㄢˇ ㄐㄧㄠ ㄓㄨˋ ㄈㄚˇ