A fan (10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h) comprising:
- a first annular conveying element (11), fluidly connectable with a source (120, 121, 122, 123, 203, 205 405, 410, 412) of a primary air flow (F1) and defining therein a first passage (12) for said primary air flow (F1);
- a first mouth (19) receiving, in use, a first aliquot of said primary air flow (F1) from said first passage (12);
- a first Coanda surface (20) on which said first mouth (19) directs, in use, said first aliquot of said primary air flow (F1);
- a first opening (14) fluidly connected with said first mouth (19) and crossable, in use, by said first aliquot of said primary air flow (F1) coming out of said first mouth (19) and by a secondary air flow (F2) drawn by said primary air flow (F1);
- and
- a second annular conveying element (30), fluidly connected with said first annular conveying element (11) and defining therein a second passage (32) for a second aliquot of said primary air flow (F1);
- said second annular conveying element (30) comprising, in turn:
- at least one second mouth receiving (35), in use, said second aliquot of said primary air flow (F1) from said second passage (32) and fluidly connected with said opening (14);
- and
- at least a second Coanda surface (36) onto which said second mouth (35) directs, in use, said second aliquot of said primary air flow (F1);
- said fan (10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h) further comprising at least one duct (40) fluidly connected with said first annular conveying element (11) and said second annular conveying element (30), arranged radially with respect to said first annular conveying element (11) and said second annular conveying element (30), said second annular conveying element (30) further including a pair of further radial ducts (80) which are in fluid connection with a nozzle (38) and are arranged on respective opposite radial sides of said nozzle (38) with respect to an axis (A) of said fan (10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h);
- said fan (10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h) having an outlet for said second aliquot of said primary flow (F1);
- said nozzle (38) being coaxial to said first annular conveying element (11) and said second annular conveying element (30) and radially inward of said second annular conveying element (30);
- wherein said second annular conveying element (30) comprises a pair of said second mouths (35) and a pair of said second Coanda surfaces (36) facing respectively towards said first annular conveying element (11) and towards said second annular conveying element (30)
- said nozzle (38) making it possible to eject, in use, a residual aliquot of said primary flow (F1) flowing into said second passage (32) directly in a direction parallel to said axis (A) of said fan (10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h).