Automatic sampling and sample returning system for online detection of pulverized coal pipeline

The invention discloses an automatic sampling and sample returning system for online detection of a pulverized coal pipeline, and belongs to the technical field of analysis and measurement. The system comprises a sampling pipeline, a sample return pipeline, an air return pipeline and a cyclone separator. A sampling valve and a jet pump are arranged on the sampling pipeline, a sample return valve is arranged on the sample return pipeline, and an air return valve and an air return pump are arranged on the air return pipeline. A sampling plate and a supporting plate are sequentially arranged at the lower end of the cyclone separator, a coal taking opening and a through hole are formed in the sampling plate and the supporting plate respectively, a pulverized coal online detection device is arranged above the supporting plate, and the coal taking opening moves between the through hole and the pulverized coal online detection device. The sampling plate is in sealing contact with the cyclone separator and the suppor