摘要 |
A method and a throttling device to control an air flow in a channel (1) or in a channel system. The air flow is brought to pass at least a first channel portion having a successively tapering channel cross section area being formed by a adjustable throttling device (4) in the channel, the air thereafter is led to an other channel portion having a cross section with an increased throttling formed by the adjustable throttling device, to continue flowing in the channel portion with the increased throttling over a distance being considerably longer than the distance between the outer wall of the throttling device and the inner wall of the of the channel portion to thereafter leave the second channel portion with the increased throttling at a third channel portion and be transferred into the not throttled channel. |