请教一个关于蒸馏的问题！？ < >教材上说：</P> < >To achieve maximum separation by fractional distillation:<o:p></o:p></P> < >1. The column must be flooded initially to wet the packing. For this reason it is customary to operate a still at reflux for some time before beginning the distillation.<o:p></o:p></P> < >2. The reflux ratio should be high (i.e. the ratio of drops of liquid which return to the distilling flask and the drops which distill over), so that the distillation proceeds slowly and with minimum disturbance of the equilibria in the column.<o:p></o:p></P> < >3. The hold-up of the column should not exceed one-tenth of the volume of any one component to be separated.<o:p></o:p></P> < >4. Heat loss from the column should be prevented but, if the column is heated to offset this, its temperature must not exceed that of the distillate in the column.<o:p></o:p></P> < >5. Heat input to the still-pot should remain constant.<o:p></o:p></P> < >6. For distillation under reduced pressure there must be careful control of the pressure to avoid flooding or cessation of reflux.</P> < >第一条和第三条看不明白，哪位过路大虾帮我解释解释啊？</P><!--EndFragment-->查看更多5个回答 . 4人已关注
第1天
关注盖德视界
添加小助手
