KR102558158B1 - Centrifugal impeller with partially opened shroud - Google Patents

Abstract

The present invention relates to a whole blade centrifugal impeller having a partially opened side plate, and more particularly, by opening a part of the side plate to prevent aerodynamic performance degradation, forming a plurality of blades installed inside to be long, and extending the part By applying in the form of protruding to the open side of the side plate, it relates to a full-curved blade centrifugal impeller having a partially open side plate that enables high-speed rotation while increasing the air volume and static pressure of the centrifugal impeller compared to the prior art.

Description

Centrifugal impeller with partially opened shroud {Centrifugal impeller with partially opened shroud}

The present invention relates to a full-curved blade centrifugal impeller in which the length of the blade is adjusted to increase the air volume and static pressure.

The impeller is a main part of a pump, blower or compressor, and rotates with several blades arranged at equal intervals on the circumference, and is connected to a driving motor to rotate between the blades of the impeller, which is a gas such as air or a fluid such as water and oil. When it flows, energy is created.

In addition, the blades of the impeller are generally classified into centrifugal and axial flow types, and in the centrifugal type blades, the fluid flows perpendicular to the axis of rotation, and in the axial flow type blades, the fluid flows in the direction of the rotation axis.

On the other hand, the impeller as described above is also used for mixing of fluids, and the configuration of a conventional centrifugal impeller made for mixing fluids is as follows.

1 is a front view of a conventional centrifugal impeller, and FIG. 2 is a side cross-sectional view of FIG. As shown, the conventional centrifugal impeller consists of a main plate 1, a side plate 2, a blade 3 and a rotating shaft 4, and by rotating the rotating shaft 4, fluid is sucked through the suction port S1, It is discharged to the impeller outlet (S2) through the blade passage formed by the main plate 1, the side plate 2, and the blade 3 to apply energy to the fluid.

And the blades 3 of the centrifugal impeller are connected to the main plate 1 and the side plate 2, and a plurality of blades 3 are radially arranged and the blades are formed in a slightly curved plate shape. A concave surface 3 'curved concavely inward and a convex surface 3" bent convexly outward appear in the curved feather 3. At this time, in the vicinity of the concave surface 3' bent concavely, a convex surface 3 "), the pressure of the fluid is low compared to the vicinity. Therefore, as shown in FIG. 2, due to separation of the fluid flow in the vicinity of the concave surface 3' of the blade 3, a reverse flow region is generated, and the performance of the impeller deteriorates.

And since the impeller has a limited number of blades 3 and the fluid has viscosity, the relative velocity of the fluid at the impeller outlet (S2) due to friction in the blade passage, separation of the flow, etc. is the velocity of the fluid according to the outlet blade angle Unlike, the discharge direction of the fluid gradually differs greatly from the outlet blade angle as the number of blades 3 decreases.

Due to this phenomenon, a sliding speed is generated at the impeller outlet (S2), and since the sliding speed is generated in the opposite direction to the impeller rotation direction, it causes a decrease in the pressure head of the impeller, and as the sliding speed increases, the same pressure is generated. Since the main speed must be increased for this purpose, the performance and effectiveness of the impeller are reduced.

The performance degradation of the centrifugal impeller appears as an increase in axial power and a decrease in effectiveness for driving the impeller, and if some of these factors are removed, it provides the possibility of improving the performance of the centrifugal impeller.

In the case of a centrifugal impeller with a small ratio of outlet width to diameter, the flow accelerated at the side plate inlet 2' is slightly It is reduced and accelerated again when it reaches the impeller outlet (S2), and even if the static pressure is reduced at the side plate inlet (2') of the inlet, the flow in the blade passage is accelerated without overall deceleration, so the reverse pressure gradient is In spite of the large pressure gradient in the blade passage, the flow is not separated from the side plate inlet 2'.

In the case of a centrifugal impeller with a large ratio of outlet width to diameter, the flow accelerated at the side plate inlet 2 'because the difference between the radius of curvature of the side plate 2 and the radius of curvature of the main plate 1 is large and the blade passage is short. When reaching the outlet (S2), it is greatly decelerated, and the speed distribution at the impeller outlet (S2) is discharged in a state where the side plate inlet (2') is greatly increased compared to the suction port (S1) side.

At this time, if you follow the inner wall surface of the side plate 2, a flow phenomenon similar to the flow phenomenon in which a strong reverse pressure gradient is formed occurs, so a strong peeling phenomenon occurs at the side plate inlet 2' where the flow is greatly accelerated. Due to the flow, the blade passage on the inner wall of the side plate 2 is completely blocked, and a strong reverse flow region is formed in the vicinity of the side plate outlet 2".

When this phenomenon occurs, the feather passage on the inner wall surface of the side plate 2 is completely blocked due to the separated flow, and the radial speed is greatly reduced at the side plate outlet 2 ", and the sliding speed is rapidly increased to reduce pressure generation As a result, the performance and effectiveness of the impeller are greatly reduced.

However, as the width of the impeller blade passage increases, as shown in FIG. 2, the flow is separated from the side plate, and a vortex flow occurs in the impeller blade passage, and energy loss occurs due to the separation.

As such, when the existing centrifugal impeller is applied to an in-line duct blower (In-Line-Duct-Fan), the flow from the impeller outlet (S2) is discharged in the radial direction as shown in FIG. 2 and vertically enters the wall of the duct (D). As a result, the flow on the wall of the duct is not induced in the axial direction, and energy is dissipated due to collision on the wall of the duct (D), increasing loss, so the efficiency of the in-line duct blower is rapidly reduced.

In addition, the sliding speed is a factor that greatly affects the performance of the centrifugal impeller, and as the sliding speed increases, the effectiveness of the centrifugal impeller greatly decreases.

In this way, a part of the blade passage is blocked due to the formation of the reverse flow region, that is, the separation of the flow, and the radial and tangential speeds in the reverse flow region are reduced, thereby degrading the performance of the impeller.

KR 20-0241247 Y1 (2001.07.24.)

The present invention has been made to solve the above problems, and an object of the present invention is to sufficiently increase the length of the installed blades in order to increase the strength of the whole blade centrifugal impeller in forming blades in the centrifugal impeller, side plate To have a shape that protrudes as much as an extension of a preset length toward the opened opening, but in order to prevent aerodynamic performance degradation due to this, the side plate is partially opened to increase the air volume and static pressure generated by the centrifugal impeller It is to provide a full-contorted centrifugal impeller having a partially open side plate that reduces noise through low-speed rotation.

The present invention is a means for solving the above problems,

It is a centrifugal impeller with forward-turning blades 300,

A disk-shaped main plate 200;

On one side of the main plate 200, a plurality of feathers 300 spaced apart from each other at regular intervals along the circumferential direction at regular intervals from the center point of the main plate 200;

It is installed opposite to one side of the main plate 200 in a horizontal form, connecting the upper ends (L-4) of the plurality of blades 300 to each other, and forming an open opening 410 in the center. Ring-shaped side plate (400); composed of,

The length of the blade 300 is formed to be greater than the width of the side plate 400, and a preset length is extended toward the opening 410, and the extension 310 protrudes toward the opening 410, thereby forming a centrifugal impeller. It is characterized in that high-speed rotation is possible and noise is reduced by increasing the air volume, static pressure and intensity.

As described above, in the present invention, the length of the blade applied to the centrifugal impeller is formed long, and the side plate has a structure with an open center, so that the blade extends to the central portion of the open side plate and protrudes. By doing so, there is an effect of increasing the air volume and static pressure generated by the centrifugal impeller and reducing noise through low-speed rotation.

1 is an upper plan view showing a conventional backward blade centrifugal impeller.
2 is a cross-sectional view showing a conventional backward-winged centrifugal impeller and a blower in which the impeller is disposed in an in-line duct;
3 and 4 are views of a first embodiment of a centrifugal blade centrifugal impeller having a partially open side plate according to the present invention.
5 and 6 are views of a second embodiment showing a centrifugal blade centrifugal impeller having a partially open side plate according to the present invention.
7 and 8 are views of one embodiment showing various shapes of feathers according to the present invention.
Figure 9 is a partially enlarged view showing an enlarged collar according to the present invention.

Hereinafter, the centrifugal blade impeller having a partially open side plate of the present invention as described above will be described in detail with reference to the accompanying drawings.

As shown, the centrifugal impeller having a partially open side plate according to an embodiment of the present invention is as follows.

Preferentially, the disk-shaped plate-shaped main plate 200 constituting the impeller, and on one side of the main plate 200, a plurality of feathers ( 300), and is installed in a horizontal form on one side of the main plate 200 to connect the upper ends (L-4) of the plurality of blades 300 to each other, and to prevent aerodynamic performance degradation, It consists of a ring-shaped side plate 400 partially opened by forming an open portion 410 in the center.

In the present invention, in addition to the side plate 400 partially opened, the length of the blade 300 is sufficiently increased to increase the air volume and static pressure generated in the centrifugal impeller, and to enable high-speed rotation. Various blades 300 as follows presents the shape of

The collar 300 is a forward-going collar,

The overall length (L-1) of the collar 300 in the longitudinal direction is formed larger than the width (W) of the side plate 400, and extends a preset length toward the opening 410 and extends toward the opening 410 Part 310 protrudes.

At this time, the collar 300 is combined with the side plate 400 and has a non-protruding length (L-2) that does not protrude toward the opening 410, and an extension 310 extending toward the opening 410 and protruding The protruding length (L-3) ratio of 1: 0.3 ~ 1.5 to have a ratio.

The feather 300 has two embodiments in the present invention according to various embodiments of users.

In the first embodiment, all of the plurality of collars 300 protrude the extension part 310 toward the opening part 410,

In the second embodiment, in the plurality of collars 300, a plurality of collars 300 that do not form extensions 310 and one collar 300 that form extensions 310 are alternately formed. . (Ex: 12 protruding long feathers and 36 non-protruding feathers, formed in a ratio of 1:3 to each other, so that 1 protruding feather and 3 non-protruding feathers are formed alternately. .)

In addition, the collar 300 may have various side shapes depending on the user's embodiment.

As shown in Figure 7,

The length (L-4) of the upper end coupled with the side plate 400 in the feather 300 and the length (L-5) of the lower end coupled with the main plate 200 are the same, extending to the side of the opening 410 In the first case of protruding 310,

The extension part 310 protrudes to the side of the opening part 410, but the length L-5 of the lower end has a relatively longer length than the length L-4 of the upper end, so that one side of the extension part 310 In the second case of this taper,

The length of the top (L-4) has the same length as the width of the side plate 400 so that it does not protrude toward the opening 410, but the bottom (L-5) is relatively more than the length (L-4) of the top It is formed in a long length and has a shape in which one side of the extension part 310 is tapered, so that one side of the extension part 310 gradually protrudes toward the opening part 410 toward the lower end (L-5) side. Including 3 cases,

As shown in Figure 8,

The length (L-4) of the upper end coupled with the side plate 400 in the feather 300 and the length (L-5) of the lower end coupled with the main plate 200 are the same, extending to the side of the opening 410 In the fourth case in which the 310 protrudes, but one end of the extension 310 is rounded,

The extension part 310 protrudes to the side of the opening part 410, but the length L-5 of the lower end has a relatively longer length than the length L-4 of the upper end, so that one side of the extension part 310 In the fifth case of being connected vertically to the main plate 200 after being tapered,

The length of the top (L-4) has the same length as the width of the side plate 400 so that it does not protrude toward the opening 410, but the bottom (L-5) is relatively more than the length (L-4) of the top Formed in a long length, after one side of the extension 310 is tapered, by having a form connected to the main plate 200 vertically, one side of the extension 310 is toward the lower end (L-5) side Like the sixth case to gradually protrude toward the opening 410,

In the present invention, it is possible to have a side shape of the side in any one of the first to sixth cases.

9 is an enlarged view of a part of the collar 300 according to the present invention, and the method of setting the collar 300 is as follows.

As shown in FIG. 9, the collar 300 sets a line connecting the inner end A and the outer end B in a straight line as the chord line 301 of the collar 300, and then The curve of the feather 300 can be set by specifying the relative height of the airfoil mean camber line with respect to the code line 301 .

That is, in the collar 300, a line connecting the inner end (A) corresponding to the leading edge and the outer end (B) corresponding to the trailing edge in a straight line becomes the code line 301 of the collar 300, and the code line 301 ), a curve connected by specifying a position corresponding to the average camber line of the airfoil may be a cross-sectional shape of the blade 300. Therefore, since the shape of the average camber line varies depending on the shape of the airfoil, the blade can be formed to have various curved cross sections according to the shape of the airfoil to be applied.

In addition, the attached reference angle θ1 of the collar 300 is formed from 0 ° to 180 ° (more specifically, 20 ° to 150 °), depending on the attachment reference angle θ1 and the shape of the average camber line applied The length, curved shape, inlet blade angle (β1) and outlet blade angle (β2) of the blade 300 may vary.

That is, the collar 300 is formed in a curved shape, and the inner ends A of the collar 300 are connected from the cord line 301 of the collar 300 to the inner end A of the collar 300. An attachment reference angle θ1, which is an angle formed by a tangent line L2 to an inner diameter Di, which is a diameter, may be formed from 0° to 180°. In addition, as the attachment reference angle θ1 increases, the length and cord length of the collar 300 change. In addition, as the attachment reference angle (θ1) increases, the inlet blade angle (β1) and the outlet blade angle (β2) increase, and as the attachment reference angle (θ1) decreases, the inlet blade angle (β1) and the outlet blade angle (β2) decrease. . Here, the inlet blade angle β1 is the tangent to the inner diameter Di, which is the diameter of the circle connecting the inner end (A) of the collar to the tangent (L1) to the collar 300 and the inner end (A) of the collar ( The angle formed by L2), and the exit blade angle β2 is the outer diameter Do As an angle formed by the tangent line L3 to ), it can be represented as shown.

The present invention is not limited to the above embodiments, and the scope of application is diverse, and anyone with ordinary knowledge in the field to which the present invention belongs without departing from the gist of the present invention claimed in the claims Of course, various modifications are possible.

100: axis of rotation 200: abacus
300: git 301: line of code
310: extension part 400: side plate
410: opening
C: reference point θ: back immersion angle
A : Inner end of collar B : Outer end of collar
L: center line
β1: inlet blade angle β2: outlet blade angle
θ1: attachment reference angle
Di: Diameter of the circle connecting the inner ends (A) of the collar (inner diameter)
Do: Diameter of the circle connecting the outer ends (B) of the collar (outer diameter)
L1: tangent to the collar at point A
L2: tangent to the inside diameter (Di) at point A
L3: tangent to the outer diameter (Do) at point B
L4: tangent to the collar at point B
L-1: The total length of the collar in the longitudinal direction
L-2: length of non-protruding collar
L-3: protruding length of collar
L-4: Top length of collar
L-5: Length of the bottom of the collar

Claims (7)

It is a centrifugal impeller with forward-turning blades 300,
A disc-shaped main plate 200;
On one side of the main plate 200, a plurality of feathers 300 spaced apart from each other at regular intervals along the circumferential direction at regular intervals from the center point of the main plate 200;
It is installed opposite to one side of the main plate 200 in a horizontal form, connecting the upper ends (L-4) of the plurality of blades 300 to each other, and forming an open opening 410 in the center. Ring-shaped side plate (400); composed of,
The length of the blade 300 is formed to be greater than the width of the side plate 400, and the preset length extends toward the opening 410 so that the extension 310 protrudes toward the opening 410, thereby creating a centrifugal impeller By increasing the air volume, static pressure and intensity of the air, high-speed rotation is possible and noise is reduced.
The collar 300 is
A non-protruding length (L-2) coupled to the side plate 400 and not protruding toward the opening portion 410, and a protruding length (L-3) of the extension portion 310 that extends toward and protrudes toward the opening portion 410. ) has a ratio of 1: 0.3 to 1.5,
The plurality of feathers 300 are
A plurality of feathers 300 that do not form the extension 310 and one feather 300 that forms the extension 310 are alternately formed,
The collar 300 is
The length of the top (L-4) has the same length as the width of the side plate 400 so that it does not protrude toward the opening 410, but the bottom (L-5) is relatively more than the length (L-4) of the top It is formed in a long length and has a shape in which one side of the extension part 310 is tapered, so that one side of the extension part 310 gradually protrudes toward the opening part 410 toward the lower end (L-5) side. 3 case,
The length L-4 of the upper end coupled with the side plate 400 and the length L-5 of the lower end coupled with the main plate 200 are the same so that the extension 310 protrudes to the side of the opening 410. , the fourth case in which one end of the extension 310 is rounded, or
The length of the top (L-4) has the same length as the width of the side plate 400 so that it does not protrude toward the opening 410, but the bottom (L-5) is relatively more than the length (L-4) of the top Formed in a long length, after one side of the extension 310 is tapered, by having a form connected to the main plate 200 vertically, one side of the extension 310 is toward the lower end (L-5) side In the sixth case of gradually protruding toward the opening 410,
made of any one of
The attachment reference angle (θ1) of the collar 300 is formed from 20 ° to 150 °, and the length, curve shape, and entrance collar angle of the collar 300 depend on the attachment reference angle (θ1) and the shape of the applied cross-sectional arc (β1) and exit blade angle (β2) change,
In the singgi feather 300, the line connecting the inner end (A) and the outer end (B) in a straight line is set as the chord line (301, chord line) of the collar 300, and the code line 301 of the collar 300 ) And the inner end (A) of the collar 300 at the inner end (A) of the collar 300 is the angle of attachment (θ1) formed by the tangent line L2 to the inner diameter Di, which is the diameter of the connecting circle As this increases, the length and cord length of the blade 300 change, and as the attachment reference angle θ1 increases, the inlet feather angle β1 and the exit feather angle β2 increase, and as the attachment reference angle θ1 decreases, the inlet The blade angle (β1) and the exit blade angle (β2) become small, and the inlet blade angle (β1) connects the tangent (L1) to the blade (300) at the inner end (A) of the blade and the inner end (A) of the blade is the angle formed by the tangent line L2 to the inner diameter Di, which is the diameter of the circle, and the exit blade angle β2 is the tangent line L4 to the blade 300 at the outer end B of the blade and the outer side of the blade The front wing centrifugal impeller having a partially open side plate, characterized in that the angle formed by the tangent line (L3) to the outer diameter (Do), which is the diameter of the circle connecting the ends (B).
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