Flow grid and ambient air purification device

1 . A flow grid arranged at a fluid intake side of a fluid flow generating device, the flow grid comprising:

a frame configured to be mounted to a housing of the fluid flow generating device; and

a fluid flow area connected to the frame, the fluid flow area having an outer perimeter, the outer perimeter having a diameter (douter), the outer perimeter being adjacent to the frame,

wherein the fluid flow area comprises a polygonal cell arrangement having a kaleidoscopic pattern, wherein the polygonal cell arrangement comprises at least two types of cell geometries sharing a concentric axis, each type of cell geometry being arranged concentrically to the other(s), and

wherein the polygonal cell arrangement is convex when viewed from the fluid intake side.

2 . The flow grid of claim 1 , further comprising

a nozzle extending from the frame and towards the fluid flow generating device, the nozzle being sized to correspond to the fluid flow generating device.

3 . The flow grid of claim 2 , wherein

the polygonal cell arrangement is arranged within the outer perimeter,

wherein the fluid flow area comprises a second perimeter having a second diameter smaller than the diameter (douter) of the outer perimeter, and

wherein a first type of cell geometry of the at least two types of cell geometries extends between the outer perimeter and the second perimeter.

4 . The flow grid of claim 1 , wherein

the fluid flow area comprises a first perimeter having a first diameter smaller than the diameter (douter) of the outer perimeter and a second perimeter having a second diameter smaller than the first diameter, the polygonal cell arrangement being arranged within the first perimeter, and

wherein a first type of cell geometry of the at least two types of cell geometries extends between the first perimeter and the second perimeter.

5 . The flow grid of claim 4 , further comprising:

a nozzle extending from the frame and towards the fluid flow generating device, the nozzle being sized to correspond to the fluid flow generating device, and

wherein the first diameter of the first perimeter is sized to be complementary to the diameter of the nozzle.

6 . The flow grid of claim 3 , wherein

the fluid flow area comprises a third perimeter, a fourth perimeter, . . . , and an nth perimeter, each of the third perimeter, the fourth perimeter, . . . , and the nth perimeter having a diameter sequentially smaller than the previous perimeter, and

wherein the at least two types of cell geometries include:

a second type of cell geometry,

a third type of cell geometry, and

an nth type of cell geometry,

wherein the second type of cell geometry extends between the second perimeter and the third perimeter, the third type of cell geometry extends between the third perimeter and the fourth perimeter, . . . , and

the nth type of cell geometry extends between the nth perimeter and the shared concentric axis.

7 . The flow grid of claim 1 , wherein

the fluid flow area is convex when viewed from the fluid intake side.

8 . The flow grid of claim 2 , wherein

an allowable convexity, which is measured by a ratio of a diameter of the nozzle to an axial distance between a tip of an inflexion point of a convex curve and the outer perimeter of the fluid flow area, is at least 1.5, the inflexion point of the convex curve sharing the concentric axis with the outer perimeter of the fluid flow area.

9 . The flow grid of claim 1 , wherein

the frame comprises a fluid inlet duct configured to channel an inflow of fluid into the fluid flow area and towards the fluid flow generating device, or

wherein the frame is configured to be mounted to the fluid inlet duct of the housing of the fluid flow generating device.

10 . The flow grid of claim 2 , wherein

the frame, the fluid flow area, the nozzle and a fluid inlet duct of the frame are integrally formed.

11 . The flow grid of claim 1 , wherein

the fluid flow area comprises bars forming the polygonal cell arrangement, the bars having a depth, and

wherein a ratio of the depth of a polygonal cell to a thickness of surrounding bars is in a range of from 1 mm to 20 mm.

12 . The flow grid of claim 1 , wherein each polygonal cell of the polygonal cell arrangement has a diameter in a range of from 6 mm to 25 mm.

13 . The flow grid of claim 6 , wherein the nozzle is arranged to share the concentric axis, and wherein a depth of each of the first perimeter, second perimeter, . . . , to nth perimeter is angled at an angle in a range of from 0 degrees to 45 degrees.

14 . An ambient air purification device comprising:

a housing having at least one air inlet and at least one air outlet;

a fluid flow generating device housed in the housing;

the flow grid as claimed in claim 1 , arranged at the fluid intake side of the fluid flow generating device, wherein the frame of the flow grid is mounted to the housing; and

at least one filter element arranged at a fluid intake side of the flow grid, such that an air flow generated by the fluid flow generating device enters from the air inlet(s), goes through the filter element, the flow grid and the fluid flow generating device in sequence, and exits via the air outlet(s).

15 . A flow grid arranged at a fluid intake side of a fluid flow generating device, the flow grid comprising:

a frame configured to be mounted to the fluid flow generating device; and

a fluid flow area connected to the frame,

wherein the fluid flow area comprises a polygonal cell arrangement having a kaleidoscopic pattern, wherein the polygonal cell arrangement comprises at least two types of cell geometries sharing a concentric axis, each type of cell geometry being arranged concentrically to the other(s), and

wherein the polygonal cell arrangement is convex when viewed from the fluid intake side of the fluid flow generating device.

16 . An ambient air purification device comprising:

a housing having an air inlet and an air outlet;

a fluid flow generating device in the housing; and

the flow grid as claimed in claim 15 , wherein the frame of the flow grid is mounted to the housing; and

at least one filter element arranged at a fluid intake side of the flow grid, wherein an air flow generated by the fluid flow generating device enters from the air inlet of the housing and goes through the filter element, the flow grid and the fluid flow generating device in sequence and exits through the air outlet.