Method for the production of double shell having internal and external shell, and/or cylinders of boost dryer unit, comprises connecting the internal and the external shells with one another over a sleeve-like bolt

摘要

The method comprises connecting internal and the external shells (10, 12) with one another over a sleeve-like bolt (16), which is contacted with the internal shell and also with the external shell. The bolt and the shells are pressed against each other in the area of contact zone (18) and the bolt is transferred in rotation in order to bring the both contact zones through the emerging frictional heat of the bolt and the shells. A welding connection (22) reforms between the bolt and the shells. The bolt is pressed against the shells. The method comprises connecting internal and the external shells (10, 12) with one another over a sleeve-like bolt (16), which is contacted with the internal shell and also with the external shell. The bolt and the shells are pressed against each other in the area of contact zone (18) and the bolt is transferred in rotation in order to bring the both contact zones through the emerging frictional heat of the bolt and the shells. A welding connection (22) reforms between the bolt and the shells. The bolt is pressed against the shells in order to weld with a rotation of the bolt simultaneously with the shells. The rotation of the bolt is adjusted after melting the bolts and the shells and the bolts and the shells are pressed against each other up to the welding connection is cooled at a predetermined temperature. The pressure for pressing together is selected so that it is same or higher than the contact pressure during the previous welding process. One of the both shells is equipped with an opening and the bolt is guided with the end through the opening and is pressed with the end against the other shell in order to produce the relevant friction contact. The bolt is subjected with the shell having the opening over a seat and the friction contact is produced between the bolt and the shell over the seat. The friction contact is produced between the bolt and the shell having the opening over the straight or conical seat. A protrusion of the bolt appeared in the area of the opening is taken out after the welding process. The radial interval between the shells is held during the welding process through support elements subjected between the shells. The shells is supported the shells are supported during the welding process partially through magnetic and/or pneumatic holding power. The bolt is subjected with its both front sides with the shells and the bolt is welded on its both front sides with the shells over a coaxial slider subjected through a shell opening. The bolt parts are welded with the shells and are welded during or after the connection between the bolt and the shell.