关风机又称旋转阀、锁气器，通常呈星型结构是由带有数片叶片的转子叶轮、壳体、密封件及减速器、电动机等组成。
当上部料仓的物料靠自重落下充填在叶片之间的空隙中，随叶片的旋而在下部卸出，因此，关风机可以定量而连续地卸料。
关风机可以用在收集物料系统中，作为料仓的卸料器，它特别适用于粉料、小颗粒物料，在正负压差吸送过程中将物料分离排出，因而深受化工、制药、干燥、粮食、水泥、环保、电力等行业的工程项目选用。
Fan also known as rotary valve, air lock, usually star-shaped structure is with a number of blades of rotor impeller, shell, seals and reducer, motor, etc. . When the material in the upper silo falls down by its own weight and fills the gap between the blades, it is discharged in the lower part with the rotation of the Blades, so that the fan can discharge quantitatively and continuously. The fan can be used in the system of collecting material, as the unloader of the silo. It is especially suitable for powder and small granular materials, therefore by the chemical, pharmaceutical, drying, food, cement, environmental protection, power and other engineering projects.