The utility model provides a sealing mechanism that is used for detachable tube to restraint between longitudinal baffle and casing, relates to sealed field. This sealing mechanism adopts the sealed replacement of thick plate spring leaf at present in general use sealed, solved the spring thin slice unreliable, fragile, make the big scheduling problem of the degree of difficulty, have and sealedlyreliably spend highly, and the adjustment is swift, the removable advantage of closing plate. Because sealed the tube bank is installed in the casing back basically and is leaned on tightly, the design of the friction between closing plate and the longitudinal baffle in addition can not cause and harm shells inner wall, the under unified use of two translation mechanism and tightening device, precision and the operating precision of heat exchanger when having guaranteed the installation keep, because this sealing mechanism is following axial longitudinal baffle both sides, each installs a setof identical translation mechanism, but every side independent adjustment even the longitudinal baffle varies with casing both sides clearance, completely can not influence sealed effect yet.