A disc housing intended for refiners with refining discs rotating in opposed directions relative to each other is disclosed for mechanically disintegrating and working fibrous material. The disc housing surrounds the refining discs in an air-tight manner, and is provided with an outlet for the worked fibrous material. The inside of the disc housing along its periphery is formed with a channel, which, as seen in the circumferential direction, has a continuously increasing radius, which increases all the way to the outlet, which is located tangentially as a direct continuation of the channel.