在除尘或排毒通风工程设计的局部通风计算公式中,Vo和Vx是两个常用参数符号。前者表示局部通风系统中用以排除有害物(粉尘、有害气体)的排气罩罩口截面平均风速,而后者则表示被排气罩排气气流所控制的有害物能有效地被捕入到排气罩内的必须风速,也即为排气气流作用到有害物上应 Vo and Vx are two commonly used parameter symbols in the local ventilation calculation formula for dedusting or detoxification engineering. The former indicates the average wind speed at the cross-section of the exhaust hood cover for removing harmful substances (dust and noxious gases) in the local ventilation system, while the latter indicates that the harmful substances controlled by the exhaust hood exhaust gas flow can be effectively caught Exhaust hood must wind speed, that is, exhaust gas flow to the harmful effects should be