the outer cylinder shell 1 has in each case tapered sections 18 with which the outer cylinder shell 11 rests in each case on a corresponding seat 19 on the circumferential sides of the covers 4 as a result the outer cylinder shell 1 is supported on the two covers 4 however the main support of the outer cylinder shell 1 takes place over its length by way of connecting elements 20 as are shown by way of example in fig2 and which are distributed over the circumferential faces of the outer cylinder shell 1 and the inner cylinder shell 2 moreover fig2 also shows a siphon 21 which is provided for removing condensate at the end side end of the hollow space 11 siphons 21 of this type can be provided both on the drive side and on the operator side and are of either corotating or stationary configuration a plurality of siphons of this type can also be provided in the circumferential direction different variants of the modular construction of the drying cylinder according to the invention are shown in fig3 to 7 and will be described in the following text fig3 to 5 show a circumferential section of a drying cylinder according to the invention having an outer cylinder shell 1 of small thickness d 1 and an inner cylinder shell 2 of greater thickness d 2 in comparison there is a hollow space 11 for.