Air-distribution device based on the Coanda effect with means for imparting a circulatory motion on the flow of air not properly oriented

An air-distribution device based upon the Coanda-effect, comprising a duct set upstream, which branches off into a plurality of ducts set downstream and means for deflecting the air flow that traverses the duct set upstream into one or the other of the aforesaid ducts set downstream, exploiting the Coanda effect, said means comprising a first mobile element, which is provided on a wall of the duct set upstream in the proximity of the inlet of a terminal duct and can be displaced between a first position, in which it does not interfere with said air flow and a second position, in which it projects into said flow, so that in the aforesaid first position of said first mobile element the flow enters said first duct set downstream, remaining adherent, by the Coanda effect, to a wall of the latter, whilst in the second position of the mobile element the air flow enters a second duct set downstream, tending to adhere by the Coanda effect to a wall opposite to said first wall,

• said device being wherein provided in the area that separates the initial ends of two ducts set downstream is the inlet of a recirculation passage, which gives out into one of the two ducts set downstream and is shaped in such a way as to generate an air circulation within one of said ducts that masks the inlet thereof when the air flow is deviated into the other duct set downstream.