Result: the primary factor which influenced the extraction rate was grinding degree, then it was time of distillation, solid-liquid ratio and soaking time.
结果：影响挥发油得率的主要因素为粉碎度，其次为蒸馏时间和料液比，最后为浸泡时间。
2
Good recovery result had once been achieved by steam flood, however, because of invasion of edge and bottom water, the ultimate recovery factor of steam soaking is low.