KR102676750B1 - Impeller - Google Patents

Abstract

The present invention relates to an impeller for improving the efficiency of a pump by improving suction capacity. To this end, an impeller is configured with a hub and radially at positions spaced apart by a preset distance around the hub to induce suction of fluid and discharge it. However, starting from a position spaced apart from the hub by a preset radius, the end is formed in a streamlined shape, and the end width becomes narrower toward the end compared to the starting width, and the suction side sucks fluid at a position adjacent to the hub. and an impeller consisting of a discharge side that discharges the sucked fluid, wherein the impeller is configured along a radial line at a position spaced apart by a radius r1 around the hub, and has n (a natural number of 3 or more) first lengths. A high suction type impeller including one vane and n second vanes disposed between the first vanes, having a second length smaller than the first length, and having an r2 radius larger than the r1 radius by a preset value. can be provided.

Description

High suction type impeller {Impeller}

The present invention relates to an impeller that can reduce cavitation of a pump and thereby improve the suction power of the pump.

The content described below simply provides background information related to this embodiment and does not constitute prior art.

In general, a pump is a pump that rotates an impeller to give rotational force to water and pump water through centrifugal force, and includes an impeller with a vane, a shaft that supports the impeller, and a motor that rotates the shaft.

In the pump, the fluid first enters the center of the impeller through the suction passage, receives rotational force while passing between the vanes, and the pressure increases. While passing through the vanes, the velocity energy is converted into pressure energy and enters the casing. At this time, the casing collects the fluid coming out of the impeller and discharges it through the discharge port.

As described above, the pump transports the fluid by suctioning and rising (suction). In other words, the pump sucks and transports fluid through the rotation of the impeller. At this time, the height or pressure at which the pump can transport fluid (hereinafter referred to as 'suction power') is usually expressed in m units.

Accordingly, when the fluid is water, the pump cannot have a suction power of 10 m or more under atmospheric pressure. In reality, it is not possible to suction fluid with a suction force of 10 m because some of the pressure is used due to friction loss in the suction pipe and the velocity head.

If fluid is sucked beyond 10m, cavitation may occur in the pump, causing various problems and shortening the life of the pump.

Cavitation refers to the creation of a cavity phenomenon in a liquid by vaporization. It refers to a boiling phenomenon in which the local static pressure at the inlet of the pump impeller falls to the saturated vapor pressure of the nutrient solution, generating many fine vapor bubbles. .

In other words, when the suction pressure is low and cavitation occurs, air bubbles render the impeller passage useless, reducing efficiency and total head, and ultimately leading to a sudden drop in total head, resulting in the impossibility of pumping.

In addition, the generation of bubbles causes noise and vibration in the pump, and if this condition continues, the surfaces of the impeller and casing are damaged by the shock pressure generated when the bubbles disappear.

Korean Registered Utility Model Publication No. 20-0229322 (announced on July 19, 2001)

The present invention relates to an impeller having an impeller that sucks in and discharges a fluid. By forming an impeller with vanes in a shape that can increase the area of the inlet side, the pressure drop just before the inlet of the impeller can be suppressed, thus preventing cavitation. We provide a high suction type impeller that can reduce generation.

The problems to be solved by the present invention are not limited to those mentioned above, and other problems to be solved that are not mentioned can be clearly understood by those skilled in the art to which the present invention pertains from the following descriptions. will be.

In order to solve the problem to be solved above, the high suction type impeller according to an embodiment of the present invention is an impeller of a pump to flow fluid from the inlet to the discharge port, and has a hub spaced apart from the hub by a preset distance. It is configured radially from the position to induce suction and discharge of fluid, but starting from a position spaced apart by a preset radius around the hub, the end is formed in a streamlined shape and the end width becomes narrower toward the end compared to the starting width. It is provided with an impeller consisting of a suction side for sucking fluid at a position adjacent to the hub and a discharge side for discharging the sucked fluid, and the impeller is configured along a radial line at a position spaced apart by a radius r1 around the hub. n (a natural number of 3 or more) first vanes having a first length, and r2 disposed between the first vanes and having a second length smaller than the first length, and a radius r2 larger than the r1 radius by a preset value. It may include n second vanes having a radius.

According to an embodiment of the present invention, each of the n first and second vanes has a partial surface corresponding to the inner surface with respect to the hub, a streamlined surface formed to support the smooth flow of fluid, and a partial surface corresponding to the inner surface with respect to the hub. The partial surface corresponding to the outer surface may include a diagonal diagonal surface formed to have support for the flow of fluid.

According to an embodiment of the present invention, when the number of the first and second vanes is three, the second vane may have a size that is 3-10% smaller than the first length of the first vane.

According to an embodiment of the present invention, the first and second vanes are formed inside the front and rear shrouds formed at each end of the hub, and the structural shape of the front and rear shrouds is located on one or both sides of the front and rear shrouds. It may include at least one back vane formed to offset pressure imbalance caused by the difference.

According to an embodiment of the present invention, the first and second vanes are formed inside a rear shroud formed on the back of the hub, and the rear shroud has the number, length, thickness, weight, and The number of back vanes formed on the outside may be further included as determined by considering the material.

According to an embodiment of the present invention, the back vane may be formed at each end and include a chamfer that guides friction with the fluid to be minimized and supports smooth dispersion.

According to the means for solving the problem of the present invention described above, in an impeller having an impeller that sucks in and discharges a fluid, by forming an impeller with vanes that can increase the area of the inlet side, the pressure drop just before the inlet of the impeller can be suppressed. This can reduce the occurrence of cavitation.

1 is a schematic diagram of a pump according to an embodiment of the present invention.
Figure 2 is a cross-sectional view of an impeller according to an embodiment of the present invention.
Figure 3 is a side view of an impeller according to an embodiment of the present invention.
Figure 4 is an enlarged view of the impeller impeller according to an embodiment of the present invention.
Figure 5 is a diagram for explaining the formation positions of the first and second vanes in the impeller according to an embodiment of the present invention.
Figure 6 is a side view of the impeller showing the configuration of the back vane according to an embodiment of the present invention.
Figure 7 is a diagram of a double suction pump to which an impeller is applied according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The detailed description below is provided to facilitate a comprehensive understanding of the methods, devices and/or systems described herein. However, this is only an example and the present invention is not limited thereto.

In describing the embodiments of the present invention, if it is determined that a detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of functions in the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, the definition should be made based on the contents throughout this specification. The terminology used in the detailed description is only for describing embodiments of the present invention and should in no way be limiting. Unless explicitly stated otherwise, singular forms include plural meanings. In this description, expressions such as “comprising” or “comprising” are intended to indicate certain features, numbers, steps, operations, elements, parts or combinations thereof, and one or more than those described. It should not be construed to exclude the existence or possibility of any other characteristic, number, step, operation, element, or part or combination thereof.

Hereinafter, an impeller for improving suction power will be described with reference to the attached drawings.

Figure 1 is a schematic diagram of a pump according to an embodiment of the present invention, Figure 2 is a cross-sectional view of an impeller according to an embodiment of the present invention, Figure 3 is a side view of an impeller according to an embodiment of the present invention, and Figure 4 is a This is an enlarged view of the impeller impeller according to an embodiment of the present invention, Figure 5 is a diagram for explaining the formation positions of the first and second vanes in the impeller according to an embodiment of the present invention, and Figure 6 is a view showing the formation position of the first and second vanes in the impeller according to an embodiment of the present invention. It is a side view of the impeller showing the configuration of the back vane according to an embodiment of the present invention, and Figure 7 is a diagram of a double suction pump to which the impeller according to an embodiment of the present invention is applied.

As shown in Figures 1 to 5, the pump 1 according to an embodiment of the present invention rotates the impeller 10 to give rotational force to water to pump water through centrifugal force, and is comprised of a single suction pump, a double suction pump, It may be a volute pump, a turbine pump, etc., but is not limited thereto.

The impeller 10 according to an embodiment of the present invention is mounted on the pump 1, etc., and can forcibly discharge fluid from the suction port 12 side to the discharge port 14 side by centrifugal force generated by rotation. Specifically, the impeller 10 is a hub configured to support the front and rear shrouds 110 and 120, respectively, at both ends, and the front and rear shrouds 110 and 120, respectively, at the center of the front and rear shrouds 110 and 120. (130), it may be composed of an impeller 140 that is configured between the front and rear shrouds 110 and 120 to support suction and discharge of fluid by centrifugal force caused by rotation.

In addition, at least one back vane ( 160) can be further included. That is, if the impeller 10 is a close type (equipped with both front and rear shrouds), the back vane 160 can be formed on both sides or only one of the front and rear shrouds 110 and 120, and the impeller 10 In the case of an open type (equipped only with a rear shroud), the back vane 160 can be formed only on the rear shroud 120.

The front shroud 110 may be configured to have a certain area at one end of the hub 130, for example, at the front.

The rear shroud 120 may be configured to have a certain area at the other end of the hub 130, for example, on the back.

When the front and rear shrouds (110, 120) are configured to have a certain area at each end of the hub (130) (closed type impeller), the impeller (10) has fluid in the space between the front and rear shrouds (110, 120). A flow path is formed to allow suction and discharge. That is, the impeller 10 has an inlet 12 formed between the front and rear shrouds 110 and 120 at a position corresponding to the front of the hub 130, and the front and rear of the impeller 10 at a position corresponding to the rear side of the hub 130. A discharge port 14 is formed between the face shrouds 110 and 120. In addition, the flow path formed between the front and rear shrouds 110 and 120 is formed in a streamlined shape to induce a smooth flow of fluid from the intake port 12 to the discharge port 14. In this case, the front shroud 110 is formed in a streamlined shape to minimize damage due to friction with the fluid when the impeller 10 rotates at high speed due to the characteristics of the front shroud 130, and the rear shroud 120 is For example, it may be formed in a shape that adopts a structure to maintain airtightness with a characteristic formed on the back of the hub 130, and a motor formed on one side of the pump.

The hub 130 is located at the center, supports the front and rear shrouds 110 and 120, and maintains a connection with the motor included in the pump 1, allowing the impeller 10 to rotate at high speed. Support to make it happen. In this case, the center of the hub 130 may include an insertion hole 132 that supports insertion and fixation of the motor shaft extending from the motor.

In the pump 1 having the above-described structure, the impeller 10 may be provided with an impeller 140 having a structure to increase the size of the intake port 12, a portion through which fluid flows, in order to improve the suction capacity. You can. Specifically, the impeller 140 of the impeller 10 has n (n is a natural number of 3 or more) number of first vanes ( 142) and the first vane 142, and may be composed of n second vanes 144 arranged with the end within the second radius r2 having a value greater than the first radius r1 as the starting point. .

In addition, each of the second vanes 144 is disposed between each of the first vanes 142, and may be configured in a plurality radially around the hub 130. For example, the first vane 142 may be composed of three vanes, and the second vane 144 may be composed of three vanes. Of course, it is not limited to this, and the number of first and second vanes 142 and 144 may vary depending on the installation purpose, installation environment, or head efficiency.

The first vane 142 starts at a position spaced apart by a first radius r1 based on the center point of the hub 130 and is formed to end at the outer periphery of the rear shroud 120, and the second vane 144 is It may be formed to start at a position spaced apart by a second radius r2 based on the center point of the hub 130 and end at the outer periphery of the rear shroud 120. In this case, the first and second vanes 142 and 144 are formed in a streamlined shape like an involute curve to allow fluid to flow smoothly from the suction port 12 to the discharge port 14, and the second radius r2 is It may have a value greater than the first radius (r1). Accordingly, the first vane 142 is formed to be longer than the second vane 144 by the difference between the first and second radii (r1, r2), so that the size of the suction port 12 can be increased.

In addition, the part corresponding to the start located on the suction port 12 side of the first and second vanes 142 and 144 is called the starting width L1, and the part corresponding to the end located on the discharge port 14 side is called the end width. It is called (L2), and the start width (L1) and end width (L2) can be formed in a length ratio of 1:0.3 to 0.6. Here, the reason why the starting width is larger than the ending width is to minimize damage caused by impact with the fluid sucked by centrifugal force. In this case, if the end width (L2) is less than 0.3 length ratio, the ends of the first and second vanes (142, 144) can be easily damaged by fluid with centrifugal force, and if it exceeds 0.6, rotation efficiency is reduced due to increased weight. You can do it.

Additionally, the first and second vanes 142 and 144 may be formed with an obtuse formation angle a1 between the start and end, with respect to the center of the hub 130. Here, the formation angle (a1) of the first and second vanes 142 and 144 may be 160° to 175°.

Meanwhile, the impeller 140 composed of the first and second vanes 142 and 144 may be formed on a close-type impeller 10 having a front shroud 110 and a rear shroud 120. In this case, the impeller 140 is provided with a first contact surface 140a in close contact with the surface of the front shroud 110 and a second contact surface 140b in close contact with the surface of the rear shroud 120. The first contact surface 140a becomes narrower with respect to the second contact surface 140b from end to end.

On the other hand, when the impeller 140 is formed on the open type impeller 10, that is, when it is formed on the impeller 10 provided only with the rear shroud 120, only the second contact surface 140b is formed on the rear shroud ( The impeller 140 may be formed in close contact with 120).

Meanwhile, the cross section of the impeller 140 having the first and second vanes 142 and 144 of the impeller 10 described above is a surface corresponding to the inner side with respect to the hub 130 and is the start of the impeller 140. It is formed as a streamlined surface 146 that supports smooth guidance of fluid and dispersion of fluid and impact from the width L1 to the end width L2, and has a cross-sectional thickness as the surface corresponding to the outside based on the hub 130. It may be composed of a diagonal surface 148 in a diagonal shape to support and disperse the fluid to ensure smooth flow.

By using the impeller 140 having this structure, the size of the suction port 12 through which fluid is sucked can be increased to lower the required suction head (NPSHr) at the same effective suction head (NPSHa). The explanation is as follows.

Due to differences in formation positions of the first and second vanes 142 and 144, the first and second vanes 142 and 144 may be formed to have different lengths. Specifically, when the number of each of the first and second vanes 142 and 144 is three, the second vane 144 has a length (hereinafter, ' It may be desirable to adjust the forming position to have a 'second length').

In other words, when the first vane 142 is formed at a first radius r1 based on the center point of the hub 130, which is the formation position, the second vane 144 is 3-10% longer than the first length. It may be desirable to form it at a location to have a small length, that is, at a second radius r2 based on the center point of the hub 130.

Meanwhile, the second length of the second vane 144 is determined by the installation location of the pump 1 (elevation above sea level), atmospheric pressure (Pa), saturated vapor pressure (kgf/m2) (Pvp), specific weight (kgf/m3) (r) ), suction head (m) (Hz), loss head (m) (Hf) according to the suction pipe connected to the pump (1), effective suction head ( Using NPSHa), the required suction head (HPSHr), which is the loss head generated from the pump 1 itself, can be determined according to the condition that satisfies Equation 2 below.

In Equation 2, a may mean margin ratio.

Meanwhile, the back vane 160 is configured on the front shroud 110 or the rear shroud 120 to minimize the axial thrust by canceling out the pressure difference that acts as an area imbalance due to the structural difference between the front and rear shrouds 110 and 120. This suppresses vibration and improves the durability of the pump. For example, the back vane 160 may be formed on the rear shroud 120.

Additionally, the back vane 160 may be formed to have a certain height on the rear shroud 120 and may be formed radially with respect to the hub 130.

Additionally, as shown in FIG. 6, the back vane 160 may be formed in a streamlined shape to smoothly distribute the pressure acting on the shroud.

In addition, each end of the back vane 160 may be provided with a chamfer 162 that minimizes friction with the fluid and supports the fluid to smoothly distribute pressure.

Accordingly, the back vane 160 reduces axial thrust by offsetting the pressure imbalance caused by the structural shape difference between the front and rear shrouds 110 and 120. In addition, when the back vane 160 is formed on the rear shroud 120, it may have the side effect of reducing axial thrust by inducing the pressure acting on the rear to flow into the discharge port 14.

When the impeller 10 having the above-described configuration is applied to a double suction pump, it is as shown in FIG. 7. Specifically, the suction capacity can be improved by increasing the area of the suction port 12 of the double suction pump.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations can be made by those skilled in the art without departing from the essential characteristics of the present invention. Accordingly, the embodiments expressed in the present invention do not limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas that are equivalent or within the equivalent scope should be construed as being included in the scope of rights of the present invention.

10: impeller 110: front shroud
120: rear shroud 130: hub
132: Insertion hole 140: Wing car
142: 1st vane 144: 2nd vane
140a: first contact surface 140b: second contact surface
146: streamlined side 148: diagonal side
160: back vane 162: chamfer

Claims (3)

In the impeller of the pump to flow fluid from the suction port to the discharge port,
herbs,
It is configured along a radial line at a position spaced apart by a preset distance around the hub to induce suction and discharge the fluid. Starting from a position spaced apart by a preset radius around the hub, the end is formed in a streamlined shape and the starting width is Compared to the hub, the end width becomes narrower toward the end, and is provided with an impeller consisting of an inlet side that suctions fluid and an outlet side that discharges the sucked fluid at a position adjacent to the hub,
The wing car,
It has a structure to increase the size of the intake port,
n (a natural number of 3 or more) first vanes configured along a radial line at a position spaced apart by a radius r1 around the hub and having a first length;
It includes n second vanes disposed between the first vanes, having a second length smaller than the first length, and having an r2 radius larger than the r1 radius by a preset value,
Each of the n first and second vanes is,
The partial surface corresponding to the inner surface based on the hub is a streamlined surface formed to support the smooth flow of fluid,
The partial surface corresponding to the outer surface with respect to the hub includes a diagonal diagonal surface formed to have support for the flow of fluid,
The number of the first and second vanes is three, and the second vane has a size that is 3-10% smaller than the first length of the first vane,
In the first and second vanes, the part corresponding to the start located on the suction port side is called the starting width (L1), and the part corresponding to the end located on the discharge port side is called the end width (L2). ) and end width (L2) are high suction impellers, characterized in that they are formed at a length ratio of 1:0.3 ~ 0.6.
According to paragraph 1,
The impeller is,
It is a closed type with front and rear shrouds formed on both ends of the hub to form impellers on the inside.
In the front or rear shroud,
A high suction type impeller comprising at least one back vane that cancels out the pressure imbalance caused by the structural shape difference between the front and rear shrouds. delete