Radial fan wheel, fan unit and radial fan arrangement
A radial fan wheel comprising vanes ( 2 ) which are inclined against the rotational direction ( 8 ) (radial impeller inclined towards the rear), the outer edge regions ( 14, 7 ) of the top and bottom disks ( 3,4 ) projecting past the effective diameter (DAs) of the vanes. The diffusion space thus established between the bottom and top disks ( 1,3 ) and the effective and outer diameter (Das, DN) of the vanes enables the kinetic energy of the fluid to be effectively converted into static pressure). The cross-section of the diffusion space is thus embodied in such a way that it expands radially outwards in a rectangular or trapezoidal manner
1. Radial fan arrangement comprising:
(a) a radial fan wheel, wherein the radial fan wheel is rotatable in a direction of rotation, the radial fan wheel comprising:
(i) a top disk comprising an inlet opening and an outer edge defining a top disk diameter,
(ii) a bottom disk comprising an outer edge defining a bottom disk diameter, wherein the top disk diameter and the bottom disk diameter are equal, and
(iii) a plurality of vanes, wherein the top disk and the bottom disk are joined to one another by way of the vanes, wherein the vanes extend axially and are inclined from inside to outside against the direction of rotation of the radial wheel, wherein the vanes have inner edges and outer edges,
wherein the top disk diameter and the bottom disk diameter each exceed an effective diameter formed by the outer edges of the vanes by 8% to 25%, such that the top disk and bottom disk include respective outer peripheral areas extending radially outwardly past the outer edges of the vanes, wherein the outer peripheral area of the top disk defines a first side wall of an annular diffusion space, and wherein the outer peripheral area of the bottom disk defines a second side wall of the annular diffusion space, with the annular diffusion space including a free space extending axially in between the outer peripheral area of the top disk and the outer peripheral area of the bottom disk, wherein the free space of the annular diffusion space is free of vanes, wherein the side walls of the diffusion space defined by the outer peripheral areas of the top disk and bottom disk are straight in cross section and extend parallel to each other and radially outwardly,
wherein a tangent to each vane at its inner edge and a corresponding tangent to a concentric circle at its inner edge together define an angle of contact of 22°,
wherein a tangent to each vane at its outer edge and a corresponding tangent to a concentric circle at its outer edge together define an angle of emergence of 31°; and
(b) a zone adjacent radially to the diffusion space and comprising no guide elements substantially affecting the pressure and/or velocity profile of a fluid flowing through the zone, the radial fan wheel not being enclosed by a surrounding spiral housing.
2. Radial fan arrangement according to claim 1 , in which the outer diameter of the diffusion space exceeds the effective diameter of the vanes by 8% to 20%.
3. Radial fan arrangement according to claim 1 , in which the inlet opening of the top disk is expanded towards the inside of the fan wheel in a trumpet shape.
4. Radial fan arrangement according to claim 3 , in which the inside edges of the vanes have a convex curvature in the area of connection to the top disk.
5. Radial fan arrangement according to claim 1 , in which the bottom disk is furnished with a hub arrangement.
6. Radial fan arrangement according to claim 1 , further comprising an intake plate having an integrated inlet nozzle, the intake plate being connected via an intake plate mount by means of supports to a drive unit mount supporting a drive unit, wherein the fan wheel is arranged on a drive shaft between the drive unit and inlet nozzle.
7. Radial fan arrangement according to claim 1 , in which the space in which the free-running radial fan wheel is arranged is a climate control blower casing.
8. Radial fan wheel, wherein the radial fan wheel is rotatable in a direction of rotation, the radial fan wheel comprising:
(a) a top disk comprising an inlet opening and an outer edge defining a top disk diameter;
(b) a bottom disk comprising an outer edge defining a bottom disk diameter; and
(c) a plurality of vanes, wherein the top disk and the bottom disk are joined to one another by way of the vanes, wherein the vanes extend axially and are inclined from inside to outside against the direction of rotation of the fan wheel, wherein the vanes have inner edges and outer edges,
wherein the top disk diameter and the bottom disk diameter each exceed an effective diameter formed by the outer edges of the vanes, such that the top disk and bottom disk include respective outer peripheral areas extending radially outwardly past the outer edges of the vanes, wherein the outer peripheral area of the top disk defines a first side wall of an annular diffusion space, wherein the outer peripheral area of the bottom disk defines a second side wall of the annular diffusion space, with the annular diffusion space including a free space extending axially in between the outer peripheral area of the top disk and the outer peripheral area of the bottom disk, wherein the free space of the annular diffusion space is free of vanes, wherein the side walls of the diffusion space defined by the outer peripheral areas of the top disk and bottom disk are straight in cross section and extended parallel to each other and radially outwardly,
wherein a tangent to each vane at its inner edge and a tangent to a corresponding concentric circle at its inner edge together define an angle of contact of 22°, and
wherein a tangent to each vane at its outer edge and a corresponding tangent to a concentric circle at its outer edge together define an angle of emergence of 31°.