Vacuum machines should be installed in the ventilation and dry cleaning establishments.
真空机应安装在干燥通风和清洁的场所。
2
Ventilation of starting rotation device ventilation pipe is from Axial flow of swirl hole inner surface takes air leads to vacuum cavity, model existence of scale effect.
起旋室通气井通风系由旋流洞内表面轴向水流“挟带”空气而致空腔内气体压强减小进入，模型存在缩尺效应。
3
Higher temperature, oil temperature increase, decrease viscosity, steam increased, the limit will cause a vacuum up, we should strengthen the ventilation cooling.