CENTRIFUGAL FAN Russian patent published in 2003 - IPC

FIELD: mechanical engineering; fans and ventilators. SUBSTANCE: invention relates to centrifugal fans and their intake devices. Proposed fan contains scroll housing 1, shaft 2, impeller 3 with blades 4 and cover disk 5, suction branch pipe 6 with cylindrical section 7, outlet branch pipe 8 equal to width L of housing 1, circulation clearance 11 between branch pipe 6 and disk 5, guide vane assembly made in form of plate 13 connected with surface 9 of branch pipe 6 in zone of maximum opening of housing. Width of housing 1 is L= (0.0-1.1)D, length of branch pipe 6 is L_in = (0,40...0,63)D, diameter at inlet into impeller 3 is D_in = (0,66...0,69)D, where D is diameter of impeller 3. Plate 13 brakes toroidal flow in chamber 10, thus forming stream in clearance 11 directed along surface 12 of disk 5. this increases zone of flow over disk 5 and blades 4 together with inlet leveled flow on section 7 without separation. EFFECT: enlarged range of flow coefficient ϕ and pressure coefficient ϕ. at large values of coefficient ψ. 6 cl, 4 dwg