Large-drop coal dropping pipe with air return function

The invention relates to a large-drop coal dropping pipe with an air return function. Compared with the prior art, the defect of environmental pollution because high-pressure air flow containing coal dust overflows around a guide chute due to coal flow impact at the bottom of the coal dropping pipe is overcome. According to the large-drop coal dropping pipe, a body of the coal dropping pipe is installed below a head hopper of a belt conveyor, an air-look device is installed on the lower part of the body of the coal dropping pipe, the lower part of the air-look device is installed in the guide chute, the large-drop coal dropping pipe further comprises an air return pipeline, an upper opening is formed in the upper part of the pipe wall of the body of the coal dropping pipe, a lower opening is formed in the lower part of the pipe wall of the body of the coal dropping pipe, the upper opening longitudinally corresponds to the lower opening, the air return pipeline is installed on the pipe wall of the body of the coal dropping pipe, the upper end of the air return pipeline is communicated with the upper opening, and the lower end of the air return pipeline is communicated with the lower opening. According to the large-drop coal dropping pipe, a high-pressure air flow area, which is caused by coal flow dropping, at the bottom of the coal dropping pipe is connected with an upper low-pressure air flow area, and the air flow containing the coal dust is led to flow to the upper part of the coal dropping pipe by utilizing pressure difference.