Relay ventilation device

The utility model discloses a relay ventilation device. The device comprises a pit, a high-pressure air supply fan, a drying box, a ventilating pipe and an air outlet box, the mine pit is provided with an air inlet pipe; a high-pressure air supply fan is mounted on the ground surface at one end of the air inlet pipe; a drying box is mounted in the pit at one end of the air inlet pipe; an air inletconnector in the middle of the top end of the drying box is fixedly connected with the air inlet pipe. Air outlet boxes are mounted on the two sides of the drying box through ventilation pipes; an evaporator is mounted in the baffle below the filter screen; a condenser is installed in the baffle below the evaporator, one end of the water storage tank is connected with the evaporator through a water pipe, a compressor is installed at the position, at the other end of the baffle, of the inner wall of the drying box, and the output end of the compressor is fixedly connected with the evaporator and the condenser through