通风管道断面形状的选择
Selection of cross section shape of ventilation pipe
通风管道断面的形状一般分矩形和圆形2种，在断面积相同的情况下，圆形的通风管道不仅阻力较小，强度大，也节省管材。对于圆形通风管道来说，直径越小越容易制造，而且保温也比较方便。但矩形通风管道的管件制作比圆形通风管道的制作要容易一些，且布置也比圆形通风管道要简单。一般情况下，通风管道截面较小而管中流速较高时，适合采用圆形通风管道；通风管道截面较大时，宜采用矩形通风管道，还可以充分利用建筑空间。对于矩形通风管道来说，宽与高的比例越接近于1越好，不仅可以节省运行的动力，还可以节省投资。
The cross-section shape of the ventilation pipe is generally divided into two kinds: rectangular and circular. Under the same cross-section area, the circular ventilation pipe not only has small resistance and large strength, but also saves pipe materials. For circular ventilation pipes, the smaller the diameter, the easier to manufacture, and the more convenient the insulation. However, it is easier to make the pipe fittings of rectangular ventilation pipe than that of circular ventilation pipe, and the layout is also simpler than that of circular ventilation pipe. Generally, when the cross-section of the ventilation pipe is small and the flow velocity in the pipe is high, the circular ventilation pipe is suitable; when the cross-section of the ventilation pipe is large, the rectangular ventilation pipe is suitable, and the building space can be fully utilized. For rectangular ventilation ducts, the closer the ratio of width to height is to 1, the better. It can not only save running power, but also save investment.
通风管道的布置
Arrangement of ventilation pipes
通风管道的布置直接关系到通风系统的总体布置，要与其他专业紧密配合，不仅要协调美观，还要符合总图专业的各项规定。如果通风管道的排风点较多时，可以采用大断面的集合管连接各支管；通风管道的布置应尽量顺直，从而可以避免复杂的局部管件；输送的气体中如果含有液滴，通风管道应设置坡度，并在通风管道的低点处设水封管，便于排除积液；通风管道上应设置调节和测量装置，便于系统的运行控制。
The layout of the ventilation pipe is directly related to the general layout of the ventilation system. It should be closely coordinated with other disciplines, not only to coordinate the aesthetics, but also to comply with the provisions of the general drawing discipline. If there are many exhaust points of the ventilation pipe, the large cross-section manifold can be used to connect the branch pipes; the layout of the ventilation pipe should be as straight as possible, so as to avoid complex local pipe fittings; if there are liquid drops in the transported gas, the ventilation pipe should be set with a slope, and a water seal pipe should be set at the low point of the ventilation pipe, so as to eliminate the liquid; the ventilation pipe should be set with adjustment and measurement The device is convenient for the operation control of the system.