關風機又稱旋轉閥、鎖氣器，通常呈星型結構是由帶有數片葉片的轉子葉輪、殼體、密封件及減速器、電動機等組成。

當上部料倉的物料靠自重落下充填在葉片之間的空隙中，隨葉片的旋而在下部卸出，因此，關風機可以定量而連續地卸料。

關風機可以用在收集物料系統中，作為料倉的卸料器，它特別適用于粉料、小顆粒物料，在正負壓差吸送過程中將物料分離排出，因而深受化工、制藥、干燥、糧食、水泥、環保、電力等行業的工程項目選用。

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.