Device for adjusting an air volume flow

A device for adjusting an air volume flow, in particular in an air distribution network, wherein the device has an air channel which can be flowed through, wherein the air channel defines a longitudinal centre axis and radial directions,

• wherein the device has a throttle which is arranged in the air channel,
• wherein the throttle has at least a first throttle portion having first blocking elements and a second throttle portion having second blocking elements, wherein the position of the second blocking elements can be changed relative to the first blocking elements in order to change a size of a cross section, which can be flowed through, of the air channel,
• wherein in a first end position of the second blocking elements relative to the first blocking elements a minimum size of the cross section which can be flowed through is achieved and, in a second end position, a maximum size of the cross section which can be flowed through is achieved,
• wherein the first blocking elements and the second blocking elements are configured in such a manner that in approximately all positions between the first end position and the second end position in approximately any radial direction they form a portion of the cross section which can be flowed through,
• wherein the cross section which can be flowed through is expanded in at least some of the positions between the first and second end positions in the direction towards the longitudinal centre axis,
• wherein the first blocking elements terminate in a region of the longitudinal centre axis in a common central blocking centre portion,
• wherein the second blocking elements form free ends in a region of the longitudinal centre axis and
• wherein the free ends of the second blocking elements are arranged around a central free region which is greater in cross section than a cross section of the central blocking central portion, whereby a free annular region which is covered only partially by the first blocking elements is provided.