The rigid impeller feeder, commonly known as the unloader or ash discharge valve, is mainly suitable for dust removal and cleaning in industries such as power plants, cement plants, chemical plants, packaging machines, and conveying batching systems. It is used for air locking or quantitative feeding when conveying dry powdered materials, and can also be used for ash discharge under the ash hopper of dust collectors and air preheaters. Its structure is simple, its performance is stable, and it is easy to operate and maintain. It is an ideal supporting component in conveying, unloading, and batching systems.