Ventilating opening of steel structure grain depot

The utility model relates to a ventilating opening of a steel structure grain depot. The ventilating opening includes a cylindrical body, a top cover, and a quick fumigating joint. The technical main points are that a flange and cylindrical body connecting lugs with hinge holes are arranged on the outer rim of the cylindrical body, the cylindrical body connecting lug is horizontally arranged on the outer rim of the cylindrical body, the top cover is equipped with lock holes that correspond to the flange in position, the outer rim of the cylindrical body is equipped with screw-in locks that correspond to the lock holes. The top cover is provided with top cover connecting lugs with hinge holes. The top cover connecting lugs are hinged to the cylindrical body connecting lugs through hinge shafts. A sleeve with the cross section that gradually decreases from the outer end of the top cover to the inner end of a grain depot is arranged inside the cylindrical body. The quick fumigating joint is arranged just on the top of the outer rim of the cylindrical body. The ventilating opening has the characteristics of being high in rigidness, simple in structure and reasonable in design, convenient to use, scientific and practical, etc. Through adoption of the sleeve, after the sleeve is connected to a blower fan and a fumigating wind inlet, the wind pressure of inlet wind gradually increases when the sleeve is gradually reduced, the wind pressure is released at a wind outlet, and the lift of the ventilating opening is greatly increased. Therefore, the technical disadvantages that a conventional ventilating opening is short in lift and then has a poor ventilation effect in the middle of a grain depot are thoroughly solved.