局部排气罩用于捕获有害物质。其性能直接影响到局部排气系统的技术经济指标。局部抽气罩具有良好的性能，如封闭的罩，可以获得良好的结果，较小的风量。由于生产设备和运行方式的不同，排气罩的形式多种多样。
Local exhaust hood is used to capture harmful substances. Its performance directly affects the technical and economic indicators of local exhaust system. Local exhaust hood has good performance, such as closed hood, can achieve good results, smaller air flow. Due to the difference of production equipment and operation mode, the forms of exhaust hood are various.