An apparatus for a thermal treatment of a textile web includes at least one drum with a perforated casing surface around which a material web can be at least partially wrapped, at least one connecting element, and a patterning shell with a plurality of openings separated by ridges fitted onto the casing of the drum. The patterning shell includes at least two segments detachably connected with aid of the at least one connecting element. The at least one connecting element is arranged on or integrated into a ridge.

An apparatus for desizing and/or shrinking a textile fabric, the textile fabric having a length and a width, the method including moving, lengthwise, the fabric, and wetting the fabric within a first pool of liquid, the first pool of liquid including water; passing the fabric through a chamber, and in the chamber contacting the fabric with at least one heatable roller heated at a treatment temperature; soaking the fabric with a main pool of liquid, the main pool of liquid including water; and treating the fabric with ozone. The apparatus includes a first module for wetting the fabric, a second module with a heatable roller for heating the fabric, a third module for soaking the fabric, and fourth module for treating the fabric with ozone. The second module may optionally be integrated with the first module.