KR20130112477A - Centrifugal pump - Google Patents

Centrifugal pump Download PDF

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Publication number
KR20130112477A
KR20130112477A KR1020120034879A KR20120034879A KR20130112477A KR 20130112477 A KR20130112477 A KR 20130112477A KR 1020120034879 A KR1020120034879 A KR 1020120034879A KR 20120034879 A KR20120034879 A KR 20120034879A KR 20130112477 A KR20130112477 A KR 20130112477A
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KR
South Korea
Prior art keywords
shroud
impeller
centrifugal pump
casing
fluid
Prior art date
Application number
KR1020120034879A
Other languages
Korean (ko)
Inventor
민영욱
김명호
이상구
김용균
이대호
Original Assignee
현대중공업 주식회사
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Application filed by 현대중공업 주식회사 filed Critical 현대중공업 주식회사
Priority to KR1020120034879A priority Critical patent/KR20130112477A/en
Publication of KR20130112477A publication Critical patent/KR20130112477A/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/18—Rotors
    • F04D29/22—Rotors specially for centrifugal pumps
    • F04D29/24—Vanes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/44—Fluid-guiding means, e.g. diffusers

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Abstract

PURPOSE: A centrifugal pump is provided to reduce an axial trust generated by the pressure difference of the front and rear surface parts of an impeller, thereby facilitating the impeller work of fluid. CONSTITUTION: A centrifugal pump includes an impeller and a casing (40). The impeller includes a rear shroud (10), multiple blades, and a front shroud (30). A shaft tube body (11) is provided that the rotating shaft is penetrated and coupled to the center of the rear shroud. The blades bend and extend, along the radial direction, from the outer circumferential surface of the shaft tube body, which protrudes forward of the rear shroud, to the edge of the rear shroud. The front shroud covers the front of the plurality of blades, and has a passage between the rear surface (12) and the spaced front surface of the rear shroud and has an inlet (31) of fluid at the center part between the front shroud and the shaft tube body. The casing has a gap through the leakage fluid and passes between the casing and the front surface of the front shroud, and covers the outer circumferential parts of the front shroud and the rear shroud of the impeller. The axial trust reducing means is provided in the casing in order to prevent the axial trust from being generated by the pressure difference between the front surface part and the rear surface part of the impeller at the time of impelling the fluid of the impeller.

Description

Centrifugal pump

The present invention relates to a centrifugal pump, and more particularly, to reduce the axial thrust force of a plurality of helical concave groove structures that are concavely recessed inside the casing corresponding to the front face of the front shroud and bent in a direction opposite to the axial rotation direction of the impeller. By providing means, it is possible to drastically reduce the mean flow velocity of the leakage flow by smooth momentum recovery of the leakage flow in the gap between the front shroud and the casing during the impeller fluid impeller. By reducing the axial thrust caused by the difference, as a result, the impeller work of the fluid is smoothly performed, as well as the workability is improved, as well as to improve the durability of the centrifugal pump and to prevent damage, To overcome the limitation of impeller installation in centrifugal pump due to the reduction of axial thrust As relates to a centrifugal pump that is able to also enhance the reliability of the overall device.

In general, the centrifugal pump (centrifugal pump) refers to a device for supplying a fluid to a desired place using a centrifugal force.

The main components of these devices are vanes, which are winged wheels, and circular casings surrounding them.

In one of the most widely used eddy centrifugal pumps, the fluid enters at high speed near the center of the rotating vanes of the pump and is flowed into the casing by the vane, and the centrifugal force is supplied to the desired place through the discharge port of the casing. come.

In addition, since the discharge port is widened in a spiral shape, the pressure increases while the speed of the fluid decreases.

And centrifugal pumps keep the fluid flowing at high pressure, which can also be increased by connecting several vanes to a single device.

In the multistage pump of this principle, the discharge port of the vane casing is used as the suction port of the vane.

Such centrifugal pumps are used for various purposes such as water supply, irrigation, and sewage treatment devices, and are also useful as gas compressors.

As an example, looking at the centrifugal pump of the prior art as follows.

As shown in Figure 1, the centrifugal pump of the prior art is provided with a shaft body 11 through which a rotating shaft (not shown) is coupled in the center and the rear shroud 10 having a flat rear surface 12, and the rear shroud ( A plurality of blades 20 which are bent and extended to the edge of the rear shroud 10 along the radial direction from the outer circumferential surface of the shaft body 11 protruded forward 10, and a predetermined distance from the front of the rear shroud 10 Cover the front of the plurality of blades 20 so as to be spaced apart so that a flow path 25 is formed between the rear surface 12 and the front surface of the spaced rear shroud 10 and the center tube 11 is formed at the center thereof. An impeller including a front shroud 30 having an inlet 31 of a fluid therebetween, and a gap 35 between the front surface of the front shroud 30 so that a leakage flow flows, and then the front shroud of the impeller. (10,30) Cover the outer periphery The covering casing 40 is comprised.

The fluid impellered by the impeller is configured to discharge the fluid in a predetermined direction through an outlet (not shown) of the casing 40.

On the other hand, when the impeller is axially rotated by the rotating shaft, the fluid flows through the inlet 31 and is impellered along the flow path 25 while being discharged to the outer circumferential part thereof with the rear surface 12 of the rear shroud 10. On the front of the front shroud 30, so-called pressure distributions to which a constant pressure is applied are formed.

This pressure distribution can be seen, in particular, as shown in FIG. 2, also in the gap 35 through which the leakage flow between the front surface of the front shroud 30 and the corresponding inner surface of the casing 40 flows.

Here, the leakage flow is generated in the direction of the central axis at the edge of the front shroud (30).

In addition, while the pressure distribution on the inlet 31 side of the front shroud 30 is uniformly and relatively weakly distributed with respect to the entire inlet 31, the corresponding side of the rear surface 12 of the rear shroud 10 is provided. The pressure distribution has a pressure distribution that acts harder than the pressure strength on the inlet 31 side.

The so-called axial thrust force in which the impeller is pushed forward as a result of an unbalanced pressure distribution between the inlet 31 side of the front shroud 30 and the rear surface 12 side of the rear shroud 10 is broken. This will occur.

In order to improve the problems caused by the generation of such axial thrust, as shown in Figures 3 and 4, the conventional linear concave extending radially on the inner surface of the casing 40 corresponding to the front surface of the front shroud 30 The centrifugal pump has been proposed to form the groove 41 structure to reduce the average flow velocity of the leakage flow flowing into the gap 35.

However, the centrifugal pump of the prior art forms a straight concave groove structure on the inner surface of the casing corresponding to the front face of the front shroud to slightly reduce the average flow rate of the leakage flow flowing into the gap, but such a conventional flow velocity reducing concave Since the grooves have a linear structure, the flow velocity component of the fluid caused by the axial rotation of the impeller causes vortices in the linear concave grooves, so that the smooth momentum of the flow cannot be recovered. There was a problem such as being.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and reduces the axial thrust force of a plurality of helical concave groove structures that are concavely recessed inside the casing corresponding to the front surface of the front shroud and bent in a direction opposite to the axial rotation direction of the impeller. By providing means, it is possible to drastically reduce the mean flow velocity of the leakage flow by smooth momentum recovery of the leakage flow in the gap between the front shroud and the casing during the impeller fluid impeller, and thus the pressure at the front and rear of the impeller. By reducing the axial thrust caused by the difference, as a result, the impeller work of the fluid is smoothly performed, as well as the workability is improved, as well as to improve the durability of the centrifugal pump and to prevent damage, It can overcome the limitation of impeller installation in centrifugal pump due to the reduction of axial thrust force. The purpose is to provide a centrifugal pump that can increase the reliability of the device as a whole.

Centrifugal pump of the present invention for achieving the above object is provided with a shaft connected to the rotating shaft through the center and the rear shroud is flat; A plurality of blades that extend from the outer circumferential surface of the shaft body projecting forward of the rear shroud to the edge of the rear shroud in a radial direction; And covering the front of the plurality of blades so as to be spaced apart from the front surface of the rear shroud to form a flow path between the rear surface and the front surface of the spaced rear shroud, and the inlet of the fluid through the center body with the shaft body at the center thereof. An impeller having a front shroud having; And a casing which covers the outer periphery of the front shroud after the impeller so as to have a gap in which the flow of leakage flows between the front of the front shroud and the front shroud, wherein the impeller of the impeller is fluid impellered. A shaft thrust reduction means is provided in the casing to prevent axial thrust from occurring due to the pressure difference between the front part and the rear part.

In addition, in the centrifugal pump according to an embodiment of the present invention, the axial thrust reduction means is the front shroud of the front shroud so that the average flow rate of the leakage flow flowing into the gap formed between the front of the front shroud and the inner surface of the casing It may have a concave groove structure formed on the inner surface of the casing corresponding to.

In addition, in the centrifugal pump according to an embodiment of the present invention, the concave groove may be disposed at a position corresponding to the edge of the front shroud.

In addition, in the centrifugal pump according to an embodiment of the present invention, the concave groove may have a spiral concave groove structure extending in the radial direction.

In addition, in the centrifugal pump according to an embodiment of the present invention, the concave groove may be formed in plural number disposed over the entire circumferential direction of the inner surface of the casing.

In addition, in the centrifugal pump according to an embodiment of the present invention, the helical direction of the concave grooves may have a structure bent toward a direction opposite to the axial rotation direction of the impeller.

In addition, in the centrifugal pump according to an embodiment of the present invention, the concave grooves may have a structure having the same depth so that the jaws are formed in the upper and lower ends, respectively.

As described above, the centrifugal pump of the present invention has a axial thrust reduction means having a plurality of helical concave groove structures concavely recessed inside the casing corresponding to the front surface of the front shroud and bent in a direction opposite to the axial rotation direction of the impeller. When the impeller fluid is impellered, the average flow velocity of the leaked flow can be significantly reduced by smooth momentum recovery of the leaked flow flowing into the gap between the front shroud and the casing. Accordingly, the pressure difference between the front and rear of the impeller As a result, the axial thrust generated can be reduced. As a result, the impeller work of the fluid can be performed smoothly, and the workability can be improved, and the durability of the centrifugal pump can be improved and the damage can be prevented. Overcoming the limitations of impeller installation in centrifugal pumps due to reduction In addition, the reliability of the device can be increased.

1 is a schematic cross-sectional view showing a centrifugal pump according to the prior art.
Figure 2 is an enlarged view showing the main portion of the pressure distribution for the gap of the centrifugal pump according to the prior art.
Figure 3 is an enlarged view of the main portion showing the pressure distribution of the gap having a straight concave groove of the centrifugal pump according to the prior art.
Figure 4 is a schematic diagram showing the main components of the flow rate component for the straight concave groove of the centrifugal pump according to the prior art.
5 is a sectional view showing main parts of a centrifugal pump according to an exemplary embodiment of the present invention.
Figure 6 is a schematic front view showing the inner surface of the casing is formed with a spiral concave groove of the centrifugal pump according to an embodiment of the present invention.
Figure 7 is an enlarged view showing the main portion of the pressure distribution of the gap having a helical concave groove of the centrifugal pump according to an embodiment of the present invention.
8 is a schematic view showing the main components of the flow rate component for the helical concave groove of the centrifugal pump according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

As shown in Figure 5 to 8, the centrifugal pump according to an embodiment of the present invention is provided with a shaft pipe body 11 through which the rotating shaft 5 is coupled to the center and the rear shroud (10) having a flat rear surface 12 (10). ) And a plurality of blades 20 and the rear shroud 10 extending from the outer circumferential surface of the shaft body 11 protruding forward of the rear shroud 10 to the edge of the rear shroud 10 along the radial direction. Cover the front of the plurality of blades 20 so as to be spaced a predetermined distance apart from the front surface of the c) to form a flow path 25 between the rear surface 12 and the front surface of the spaced rear shroud 10 and at the center of the shaft body. An impeller including a front shroud 30 having an inlet 31 of a fluid therebetween, and a clearance 35 through which leakage flow flows between the front shroud 30 and the front shroud 30. After the impeller, front shroud ( 10, 30) comprises a casing 40 to cover the outer peripheral portion.

The fluid impellered by the impeller is configured to discharge the fluid in a predetermined direction through an outlet (not shown) of the casing 40.

And, in order to prevent the axial thrust due to the pressure difference between the front and rear of the impeller when the fluid impeller of the impeller is provided with a axial thrust reduction means in the casing (40).

Here, the axial thrust reduction means is the front shroud so that the average flow rate of the flow flow to the gap 35 formed between the front surface 32 of the front shroud 30 and the inner surface 42 of the casing 40 is reduced The concave groove 43 is formed in the inner surface 42 of the casing 40 corresponding to the front surface 32 of the 30.

The concave groove 43 is disposed at a position corresponding to the rim of the front shroud 30, and the concave groove has a structure of a spiral concave groove 43 extending along the radial direction.

The concave groove 43 includes a plurality of concave grooves disposed over the entire circumferential direction of the inner surface 42 of the casing 40.

The helical direction of the concave grooves 43 is bent toward the opposite direction of the axial rotation of the impeller.

In addition, the concave grooves 43 have a structure having the same depth so that the jaws 43a are formed at upper and lower ends thereof, respectively.

Centrifugal pump according to one embodiment of the present invention according to this configuration is the fluid flows through the inlet port 31 between the shaft body 11 of the front shroud 30 and the rear shroud 10 when the impeller is axially rotated, The introduced fluid is impellered by the impeller so as to discharge the fluid in a predetermined direction through an outlet (not shown) of the casing 40.

In addition, a part of the fluid flows in the direction of the central axis through the gap 35 between the front surface 32 of the front shroud 30 and the inner surface 42 of the casing 40 during the impellering of the fluid. Leakage flow is generated.

On the other hand, when the impeller is axially rotated by the rotating shaft, the fluid flows through the inlet 31 and is impellered along the flow path 25 while being discharged to the outer circumferential part thereof with the rear surface 12 of the rear shroud 10. On the front of the front shroud 30, so-called pressure distributions to which a constant pressure is applied are formed.

In particular, the pressure distribution also appears in the leakage flow in the gap 35 between the front surface 32 of the front shroud 30 and the inner surface 42 of the casing 40, wherein as shown in FIG. A portion of the leakage flow flows into the concave groove 43 of the inner surface 42 of the 40 and at the same time increases the momentum recovery amount of the flow rate component flowing in the circumferential direction by the spiral shape, and consequently, As the flow velocity increases, the flat flow velocity of the total leakage flow decreases by the increase in the flow rate of the leakage flow flowing in the concave groove 43, and consequently, the positive pressure recovery increases, resulting in axial thrust generated in the front and rear of the impeller. Can be reduced.

 As described above, the centrifugal pump according to an embodiment of the present invention has a axial thrust force of a plurality of spiral concave grooves concavely recessed in the inner side of the casing corresponding to the front surface of the front shroud and bent in a direction opposite to the axial rotation direction of the impeller. By providing an abatement means, it is possible to drastically reduce the average flow velocity of the leakage flow by smooth momentum recovery of the leakage flow in the gap between the front shroud and the casing during the impeller fluid impeller. By reducing the axial thrust caused by the pressure difference, as a result, the impeller work of the fluid is smoothly performed, as well as the workability is improved, and the durability of the centrifugal pump can be improved and the damage can be prevented. When the limitation of the impeller installation in the centrifugal pump due to the reduction of the axial thrust can be overcome, Reliability of the overall device would be able to increase.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, It should be understood that all of the techniques that can be easily changed and used by those skilled in the art are included in the technical scope of the present invention.

DESCRIPTION OF REFERENCE NUMERALS
10: rear shroud 11: shaft body
12: back 20: blade
30: front shroud 31: inlet
32: front 35: gap
40: casing 41: (linear) concave groove
42: inner side 43: (spiral) concave groove
43a: jaw

Claims (7)

A rear shroud provided with a shaft tube through which a rotating shaft is coupled in the center thereof and having a flat rear surface;
A plurality of blades that extend from the outer circumferential surface of the shaft body projecting forward of the rear shroud to the edge of the rear shroud in a radial direction; And
Covering the front of the rear shroud by a predetermined distance so as to cover the front of the plurality of blades to form a flow path between the back and the front of the spaced rear shroud and having a fluid inlet through the center in the center with the shaft body Front shroud;
Impeller consisting of; And
A casing covering the front shroud outer circumference of the impeller to have a gap in which leakage flow flows between the front shroud and the front shroud;
In the centrifugal pump comprising a,
Centrifugal pump, characterized in that the axial thrust reduction means is provided in the casing to prevent the axial thrust due to the pressure difference between the front and rear of the impeller during the fluid impeller of the impeller. The method of claim 1,
The axial thrust reduction means has a concave groove structure formed in the inner surface of the casing corresponding to the front surface of the front shroud so that the average flow velocity of the leakage flow flowing into the gap formed between the front surface of the front shroud and the inner surface of the casing is reduced. Centrifugal pump, characterized in that. 3. The method of claim 2,
The concave groove is disposed in the position corresponding to the edge of the front shroud centrifugal pump. The method of claim 3,
The concave groove is a centrifugal pump, characterized in that the spiral concave groove extending in the radial direction. 5. The method of claim 4,
The concave groove is a centrifugal pump, characterized in that consisting of a plurality of arranged over the entire circumferential direction of the inner surface of the casing. The method of claim 5,
Spiral direction of the concave grooves is a centrifugal pump characterized in that the structure is bent toward the direction opposite to the axial rotation direction of the impeller. The method according to claim 6,
The concave grooves are centrifugal pumps having a structure having the same depth so that the jaw is formed in the upper and lower ends, respectively.
















KR1020120034879A 2012-04-04 2012-04-04 Centrifugal pump KR20130112477A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020120034879A KR20130112477A (en) 2012-04-04 2012-04-04 Centrifugal pump

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Application Number Priority Date Filing Date Title
KR1020120034879A KR20130112477A (en) 2012-04-04 2012-04-04 Centrifugal pump

Publications (1)

Publication Number Publication Date
KR20130112477A true KR20130112477A (en) 2013-10-14

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Application Number Title Priority Date Filing Date
KR1020120034879A KR20130112477A (en) 2012-04-04 2012-04-04 Centrifugal pump

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