CN107965467B

CN107965467B - Centrifugal fan impeller for range hood

Info

Publication number: CN107965467B
Application number: CN201710318484.8A
Authority: CN
Inventors: 李年平; 王军元; 贾博贤; 茅忠群; 诸永定
Original assignee: Ningbo Fotile Kitchen Ware Co Ltd
Current assignee: Ningbo Fotile Kitchen Ware Co Ltd
Priority date: 2017-05-08
Filing date: 2017-05-08
Publication date: 2024-04-12
Anticipated expiration: 2037-05-08
Also published as: CN107965467A

Abstract

The invention discloses a centrifugal fan impeller for a range hood, which comprises a front ring and a rear ring, wherein a plurality of blades and a middle disk are arranged between the front ring and the rear ring, the blades comprise a first blade positioned between the middle disk and the front ring and a second blade positioned between the middle disk and the rear ring, the outlet end side edge of the first blade is at least partially recessed towards the axial direction of the impeller to form a first notch, the position of the outlet end side edge of the first blade corresponding to the first notch is formed into a first curve, the outlet end side edge of the second blade is at least partially recessed towards the axial direction of the impeller to form a second notch, the position of the outlet end side edge of the second blade corresponding to the second notch is formed into a second curve, and the first curve and the second curve are secondary curves. The concave notch is respectively added on the upper and lower blades of the double-suction impeller, so that pressure non-uniformity caused by uneven outlet speed can be balanced, and the fluid outlet speed can be homogenized, thereby greatly reducing the influence of 'jet flow' at the impeller outlet, improving the flow field, reducing the noise of the range hood, and especially reducing the kitchen noise under the use state of a user.

Description

Centrifugal fan impeller for range hood

Technical Field

The invention relates to a range hood, in particular to a centrifugal fan impeller for the range hood.

Background

The centrifugal fan commonly used in the range hood is a multi-wing centrifugal fan, the blades of the centrifugal fan are generally in a single circular arc shape, the number of the centrifugal fans is large, the edges of the inlet and outlet of the blades are linear, and the outlet speed schematic diagram is shown in fig. 7.

In order to solve the problems of high noise and low efficiency caused by the phenomenon of jet flow-wake generated by the impeller under the working conditions of small flow and high pressure, the blade outlet is designed into a sawtooth shape. As disclosed in chinese patent application No. 00217735.8, the outer side of the same fan blade has different radial shapes at each point in the vertical direction, for example, the outlet side of the fan blade is designed into a convex side or a concave side, or a wavy side formed by combining the two sides, and the schematic view of the outlet speed is shown in fig. 8. However, since the vane exit velocity vector plot is not zigzag, but simply convex, the above approach does not significantly improve or even potentially worsen the fluid velocity profile.

Disclosure of Invention

The invention aims to solve the technical problems of the prior art and provides a centrifugal fan impeller for a range hood, which is capable of reducing noise.

The technical scheme adopted for solving the technical problems is as follows: a centrifugal fan impeller for range hood, includes preceding circle and back circle, be provided with a plurality of blades and center plate between preceding circle and the back circle, the blade is including being located the first blade between center plate and the preceding circle, being located the second blade between center plate and the back circle, its characterized in that: the outlet end side edge of the first blade is at least partially sunken towards the axis direction of the impeller to form a first notch, the position of the outlet end side edge of the first blade corresponding to the first notch is formed into a first curve, the outlet end side edge of the second blade is at least partially sunken towards the axis direction of the impeller to form a second notch, the position of the outlet end side edge of the second blade corresponding to the second notch is formed into a second curve, and the first curve and the second curve are quadratic curves.

Preferably, to better balance the pressure non-uniformity caused by the outlet non-uniformity, the first curve has a first peak with a height a1, the second curve has a second peak with a height a2, and the parameters a1 and a2 satisfy the following relationship: a1 has a value range of 0< a1<5mm, a2 has a value range of 0< a2<5mm, and a1=a2.

In order to make the maximum speeds of the outlets of the first blade and the second blade the same, balance the fluid pressure and the mechanical load, reduce the vibration caused by the unbalance of the impeller, and reduce the velocity gradient of the fluid to cause severe turbulence, the distance between the first vertex of the first curve and the front inlet end of the impeller is b1, and the length of the first blade is L1; the distance between the second vertex of the second curve and the rear inlet end of the impeller is b2, and the length of the second blade is L2; the above parameters b1, b2, L1 and L2 satisfy the following relationship: 0.6< b1/L1<0.67,0.6< b2/L2<0.67, L1/l2=b1/b 2, and L1> L2.

Compared with the prior art, the invention has the advantages that: the concave notch is respectively added on the upper and lower blades of the double-suction impeller, so that pressure non-uniformity caused by uneven outlet speed can be balanced, and the fluid outlet speed can be homogenized, thereby greatly reducing the influence of 'jet flow' at the impeller outlet, improving the flow field, reducing the noise of the range hood, and especially reducing the kitchen noise under the use state of a user.

Drawings

FIG. 1 is a schematic view of an embodiment of an impeller of the present invention;

FIG. 2 is a schematic exploded view of an embodiment of an impeller of the present invention;

FIG. 3 is a side view of an embodiment of an impeller of the present invention;

FIG. 4 is an outlet schematic of an embodiment of the impeller of the present invention;

FIG. 5 is a schematic view of the structure of a vane of an embodiment of the impeller of the present invention;

FIG. 6 is a schematic view of the vane exit velocity of the impeller of the present invention;

FIG. 7 is a vane exit velocity schematic of a prior art impeller;

fig. 8 is a schematic view of the vane exit velocity of a prior art impeller.

Detailed Description

The invention is described in further detail below with reference to the embodiments of the drawings.

Referring to fig. 1 and 2, a centrifugal fan impeller for a range hood comprises a front ring 1 and a rear ring 2, wherein a plurality of blades 3 are fixed between the front ring 1 and the rear ring 2, and the blades 3, the front ring 1 and the rear ring 2 are fixed together in a conventional riveting manner. A middle plate 4 is arranged between the front ring 1 and the rear ring 2, thereby forming a bidirectional air inlet structure.

Referring to fig. 3 to 6, the vane 3 includes a first vane 31 positioned between the center plate 4 and the front ring 1, a second vane 32 positioned between the center plate 4 and the rear ring 2, and the first vane 31 and the second vane 32 are integrally formed. The outlet end side edge of the first blade 31 is at least partially recessed towards the axial direction of the impeller to form a first notch 311, and the position of the outlet end side edge of the first blade 31 corresponding to the first notch 311 is formed into a secondary curve, and a first curve l1; the outlet end side of the second vane 32 is at least partially recessed toward the axial direction of the impeller to form a second notch 321, and the position of the outlet end side of the second vane 32 corresponding to the second notch 321 is formed into a secondary curve, and the second curve l2.

The height at the first vertex O1 of the first curve l1 is a1, that is, the vertical distance between the first vertex O1 and the straight line portion of the outlet end side of the first blade 31. The height at the second vertex O2 of the second curve l2 is a2, i.e., the vertical distance of the second vertex O2 from the outlet end side straight portion of the second vane 32. a1 has a value range of 0< a1<5mm, a2 has a value range of 0< a2<5mm, and a1=a2.

The distance between the first vertex O1 of the first curve L1 and the front inlet end (at the front ring 1) of the impeller is b1, and the length of the first blade 31 is L1; the second apex O2 of the second curve L2 is spaced from the rear inlet end of the impeller (at the rear ring 2) by a distance b2 and the length of the second vane 32 is L2. The height dimension of the front end and the rear end of the impeller is asymmetrically distributed, namely L1 is larger than L2. Furthermore, the above parameters satisfy: 0.6< b1/L1<0.67,0.6< b2/L2<0.67, L1/L2 = b1/b2. The maximum speeds of the outlets of the first and second blades 31 and 32 can thereby be made the same, while balancing the fluid pressure with the mechanical load, reducing vibrations caused by impeller imbalance, and reducing the velocity gradient of the fluid causing severe turbulence.

In double suction impellers, the jet produces more noise due to non-uniformity in the fluid velocity distribution. The concave notch is added to each of the upper and lower blades of the double suction impeller, so that pressure non-uniformity caused by uneven outlet speed can be balanced, the arc shape of the notch can be basically matched with the speed vector curve of fluid at the outlet end of the blade, so that the fluid outlet speed can be uniform, and referring to fig. 6 (only one of the first blade 31 and the second blade 32 is shown), thereby greatly reducing the influence of 'jet' at the outlet of the impeller, improving the flow field, and reducing the noise of the range hood, especially the kitchen noise in the use state of a user.

Claims

1. A centrifugal fan impeller for range hood, includes preceding circle (1) and back circle (2), be provided with a plurality of blades (3) and chassis (4) between preceding circle (1) and the back circle (2), blade (3) are including being located first blade (31) between chassis (4) and preceding circle (1), are located second blade (32) between chassis (4) and the back circle (2), its characterized in that: the outlet end side edge of the first blade (31) is at least partially recessed towards the direction of the impeller axis (X) to form a first notch (311), the position of the outlet end side edge of the first blade (31) corresponding to the first notch (311) is formed into a first curve (l 1), the outlet end side edge of the second blade (32) is at least partially recessed towards the direction of the impeller axis (X) to form a second notch (321), the position of the outlet end side edge of the second blade (32) corresponding to the second notch (321) is formed into a second curve (l 2), and the first curve (l 1) and the second curve (l 2) are quadratic curves;

the first curve (L1) is provided with a first vertex (O1), the second curve (L2) is provided with a second vertex (O2), the distance between the first vertex (O1) of the first curve (L1) and the front inlet end of the impeller is b1, and the length of the first blade (31) is L1; the distance between the second vertex (O2) of the second curve (L2) and the rear inlet end of the impeller is b2, and the length of the second blade (32) is L2; the above parameters b1, b2, L1 and L2 satisfy the following relationship: 0.6< b1/L1<0.67,0.6< b2/L2<0.67, L1/l2=b1/b 2, and L1> L2.

2. The centrifugal fan impeller for a range hood of claim 1, wherein: the height of the first vertex (O1) is a1, the height of the second vertex (O2) is a2, and the above parameters a1 and a2 satisfy the following relationship: a1 has a value range of 0< a1<5mm, a2 has a value range of 0< a2<5mm, and a1=a2.