Abstract: A curtain consists of a web of temperature resistant material forming a web surface and may be unwound from a coil arranged on a coil core. The coil is supported by a bearing arrangement including at least one supporting surface so that the coil core, at least on one of its ends, is supported adjustably in height within a guidance. Alternatively or in combination, the curtain is guided by lateral guide bars including an arrangement for preventing the inserted curtain edge to be drawn out. Another feature is that at least two curtain webs the surfaces of which face each other have a common end bar forming a weight for the curtain.