The invention discloses a double-column top
coal caving hydraulic support having a large mining height and provided with top
coal recovery devices, and the largest height is larger than 6 m. The top
coal recovery devices are divided into three stages: the first stage adopts a swing type
tail beam, vertical swing of the swing type
tail beam is controlled by two
tail beam jacks hinged with a shield beam, and opening and closing of a coal
discharge port are realized; the second stage adopts a retractable type coal
discharge beam device, the retractable type coal
discharge beam device is controlled by a
plugboard jack to stretch and retract in the first-stage swing type tail beam, coal breaking teeth in a rectangular
pyramid or cone shape are arranged at the upper part of the end of the second-stage coal discharge beam, and coal discharge and breaking functions are realized; the third stage adopts a hinged type coal discharge and return plate beam, the hinged type coal discharge and return plate beam is hinged to the lower part of the end of the second-stage retractable type coal discharge beam, can move with the stretching and retracting of the second-stage coal discharge beam and can be controlled by a coal return jack to retract, and coal breaking and loading functions are realized. The double-column top coal caving hydraulic support is applied to full-mechanized caving mining of
hard coal resources with the thickness larger than 8 m, and the problems about top coal caving and
recovery are solved obviously.