▎ 摘　　要

NOVELTY - The device comprises an upper inserting cover (1), where the upper part of inner wall of upper inserting cover is uniformly provided with a through socket. The upper part of inner wall of upper inserting cover is slidingly connected with a gas storage box (6) through inserting port. The shaft center of upper part of inner wall of upper inserting cover is provided with a large through opening. The inner wall of upper part of upper inserting cover is connected with an air outlet pipe (4) through a large through opening. The top end of air outlet pipe is fixedly connected with a methane concentration detecting box (5). The upper part of inner cavity of methane concentration detecting box is symmetrically provided with a rotating pipe (9), where the number of rotating pipe is two. The top end of rotating pipe extends to inside of methane concentration detecting box. The bottom end of rotating pipe extends to the inside of blower. USE - The device is useful in technical field of electric material. ADVANTAGE - The device: has no barrier on outer surface when processing, so the graphene film can be perfectly covered on outer surface of copper foil; improves anti-corrosion performance of copper foil; and solves the problem that the copper foil clamping part cannot be covered caused by copper foil corrosion resistance deterioration problem when processing the graphene copper. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a preparation method of graphene copper-based composite material. DESCRIPTION OF DRAWING(S) - The drawing shows a partial structure schematic diagram of the copper foil coating device in closed state. 1Upper inserting cover 4Air outlet pipe 5Methane concentration detecting box 6Gas storage tank 9Rotating pipe