Menetelmä ja laite lämpösuojuksen varmistamiseksi pintojen välille, joilla on eri lämpötila

A method and a device for introducing a medium, a primary flow (B), with a first temperature via an inlet pipe (9) into a container (2), for example a nuclear reactor vessel, which container (2) contains a medium with a second temperature. A gap (11) is arranged between the container part (10) and the inlet pipe (9) and therein medium with the first temperature is caused to flow, thus forming a secondary flow (C). The secondary flow constitutes a thermal shield between the surfaces with different temperatures whereby thermal stresses in that part of the container (10) which surrounds the inlet pipe (9) are avoided. The invention is characterized in that the inlet pipe (9) is caused by means of a positioning member (12, 13, 14) to be positioned centrally in the container part (10) in such a way that the size of the gap (11), in a section across the inlet pipe (9), the gap (11) and the container part (10), is maintained equally large around the whole inlet pipe (9). The positioning member comprises a first, a second and a third tubular part (12, 13, 14), wherein the first tubular part (12) comprises a first spherical surface (12a), the second tubular part (13) comprises a second and a third spherical surface (13a, 13b), wherein the second spherical surface (13a) corresponds to the first spherical surface (12a) and makes contact therewith and the third tubular part (14) comprises a fourth spherical surface (14a) which corresponds to the third spherical surface (13b) and makes contact therewith.