Wind powder pipe online sampling device and method suitable for optical detection technology

The invention provides an air powder pipe on-line sampling device suitable for an optical detection technology, which comprises a connecting pipe arranged below an air powder pipe; an air sealing unit; the sample loading pipe is arranged below the air sealing unit, is communicated with the connecting pipe and is used for accommodating the falling powder when the air sealing unit stops guiding air; the optical detection window is mounted below the sample loading pipe, and light beams of external optical detection equipment penetrate through the optical detection window so as to detect the powder on the optical detection window; the reverse blowing unit is arranged between the sample loading pipe and the optical detection window, removes powder on the optical detection window through reverse blowing, and comprises a reverse blowing cavity and a plurality of reverse blowing air inlets; the blowback cavity is of a multi-petal semi-ellipsoidal structure, first focuses of all the semi-ellipsoidal structures are cir