The invention relates to a
coal-rock interface identification method, and particularly relates to a method for detecting a
coal-rock interface by phased-array
ultrasonic imaging. The method is realized by adopting a
system for detecting the
coal-rock interface on the basis of phased-array
ultrasonic imaging. The
system consists of a supporting device, a
coupling device, an ultrasonic phased-
array transducer and an imaging device. The phased-
array transducer in water transmits ultrasonic
waves to a coal
bed, the ultrasonic
waves enter the coal
bed after being transmitted to a water and coal interface, then the ultrasonic
waves are transmitted to the coal-rock interface and returned to the coal
bed, and then the ultrasonic waves are returned to the water and received by the phased-
array transducer. The thickness of the coal bed is calculated according to parameters such as the transmitting and receiving
time difference of the phased-array
transducer, and the coal-rock interface can be judged. By utilizing the advantages of the phased-array ultrasonic wave such as good
directivity,
high energy, high
measurement precision and deflection focusing as well as the characteristic of the ultrasonic wave of no scattering in the water, the coal-rock interface can be precisely identified in real time, the method can be used for adjusting the
cutting depth of a
coal mining machine roller and reducing the residual coal bed, thereby reducing the coal loss to increase the coal exploitation quantity.