Pulverized coal granularity online monitoring device

The invention provides a pulverized coal granularity online monitoring device. The device comprises an industrial personal computer and three electrostatic sensors which are distributed at equal intervals along the same circumference of the disposable air pipe, and the industrial personal computer is electrically connected with each electrostatic sensor; the signal sensing end of each electrostatic sensor is arranged in the pipe wall of the disposable air pipe and used for obtaining electrostatic signals of pulverized coal particles flowing in the disposable air pipe and sending each obtained electrostatic signal to the industrial personal computer. And the industrial personal computer is used for extracting the characteristic frequency spectrum corresponding to each electrostatic signal, obtaining the probability distribution of the pulverized coal granularity of the disposable air duct according to all the characteristic frequency spectrums, and determining the pulverized coal granularity of the disposable