Balancing device of vertical pump suitable for working conditions of high inlet pressure and lower lift

Abstract

The utility model relates to the technical field of vertical pumps, in particular to a balancing device of a vertical pump which is suitable for conveying clean media or media containing small-size impurities in the industries and fields of oil refineries, petrochemical engineering, low-temperature application, marine industry and the like under the working conditions of high inlet pressure and low lift. A balancing device consisting of a balancing box body, a balancing sleeve and a balancing drum is assembled at the lower end of a suction section; the balance box body is arranged at the bottom of the suction section through a bolt; the balance sleeve is arranged on the inner wall of the balance box body through a bolt; and the balancing drum is arranged in the balancing sleeve and is sleeved on the shaft. The bottom end of the balance pipe communicates with the interior of the balance box body, and the top end communicates with the interior of the supporting pipe. According to the technical scheme, the problems that a balancing device of a vertical pump is installed on the outlet side of the pump, the pressure of a front cavity of a balancing drum is large, the pressure of a rear cavity of the balancing drum is small, the balancing device can generate upward balancing force, upward axial force can be generated in the working process, a pump shaft is in a compressed state all the time, and operation is unstable are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a balance device of vertical pump suitable for high inlet pressure and low lift condition, and more particularly to a balance device of vertical pump suitable for high inlet pressure and low lift condition for conveying clean or small size impurity medium in oil refinery, petrochemical industry, low temperature application, offshore industry and other fields. BACKGROUND

[0002] At present, the balance device structure of the widely used vertical pump in petrochemical industry is mainly installed on the outlet side of the pump, the front cavity pressure of the balance drum is large, the rear cavity pressure is small, and the balance device generates upward balancing force.

[0003] When the inlet of the pump has high pressure, a large upward shaft head force is generated. When the pump is running, the hydraulic axial force generated by the impeller is downward. When the pump has low lift, the hydraulic axial force of the impeller is small. After being combined with the shaft head force, the resultant force direction is upward. At this time, if the force generated by the balance drum is upward, the balance of the rotor axial force cannot be achieved, and the pump shaft is always in a compressed state, which causes unstable operation.

[0004] In view of the problems existing in the prior art, it is necessary to research and design a new balance device of vertical pump suitable for high inlet pressure and low lift condition to overcome the problems existing in the prior art. SUMMARY

[0005] The balance device of the existing vertical pump is installed on the outlet side of the pump, the front cavity pressure of the balance drum is large, the rear cavity pressure is small, the balance device generates upward balancing force, upward axial force is generated during work, the pump shaft is always in a compressed state, and unstable operation and other technical problems are caused. A balance device of vertical pump suitable for high inlet pressure and low lift condition is provided.

[0006] The technical means adopted by the utility model are as follows:

[0007] A balance device of vertical pump suitable for high inlet pressure and low lift condition, comprising: a first guide shell, a secondary impeller, a final guide shell, a bushing, a suction section, a first impeller, a shaft, a secondary guide shell, a final impeller and a support pipe; the final impeller, the secondary impeller and the first impeller are sequentially mounted on the shaft from top to bottom; the outer part of each stage impeller is sequentially assembled with the support pipe, the final guide shell, the secondary guide shell, the first guide shell and the suction section from top to bottom; the shaft bushing is assembled between the suction section and the shaft;

[0008] Further, the lower end of the suction section is assembled with a balance device composed of a balance box body, a balance sleeve and a balance drum.

[0009] Further, the balance box body is mounted on the bottom of the suction section by bolts;

[0010] Further, the balance sleeve is bolted to the inner wall of the balance box;

[0011] Further, the balance drum is arranged inside the balance sleeve and is sleeved on the shaft.

[0012] Further, the balance drum is circumferentially positioned by the upper step of the shaft and the locking nut of the shaft end.

[0013] Further, the balance device is further provided with a balance pipe;

[0014] Further, the bottom end of the balance pipe is communicated with the rear cavity of the balance box, and the top end is communicated with the inside of the support pipe.

[0015] The working state of the utility model is:

[0016] The medium enters the pump from the inlet of the suction section, is pressurized by the primary impeller, the secondary impeller and the final-stage impeller in stages and then flows into the support pipe, most of the medium flows to the pump outlet and is delivered to the downstream, a small part of the medium flows to the balance box through the balance pipe, and the medium in the balance box flows to the pump inlet through the gap between the shaft bushing and the shaft and between the balance drum and the balance sleeve.

[0017] Compared with the prior art, the utility model has the following advantages:

[0018] The balance device of the vertical pump suitable for the working condition of high inlet pressure and low lift provided by the utility model is suitable for the working condition of high inlet pressure and low lift of the vertical pump, can keep the pump shaft in a slightly stretched state during the pump operation, improves the operation reliability of the pump and prolongs the service life of the pump.

[0019] In summary, the technical scheme of the utility model solves the problems in the prior art that the balance device of the vertical pump is installed on the outlet side of the pump, the front cavity pressure of the balance drum is large, the rear cavity pressure is small, the balance device generates upward balancing force, upward axial force is generated during the operation, the pump shaft is always in a compressed state, and the operation is unstable. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] Figure 1 It is a structure and medium flow direction diagram of the utility model.

[0022] In the figure: 1, locking nut 2, balance drum 3, balance pipe 4, first stage guide vane 5, secondary impeller 6, final stage guide vane 7, balance sleeve 8, balance box 9, bushing 10, suction section 11, first stage impeller 12, shaft 13, secondary guide vane 14, final stage impeller 15, support pipe. DETAILED DESCRIPTION

[0023] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0025] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0026] Unless otherwise specifically stated, the relative arrangement of parts and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application. At the same time, it should be clear that the sizes of the various parts shown in the drawings are not drawn in proportion to the actual proportions. The technology, methods and devices known to those skilled in the relevant art can not be discussed in detail, but in appropriate cases, the technology, methods and devices should be considered as part of the authorized specification. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, and not as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0027] In the description of the utility model, it needs to be understood that the directions such as '' front, back, up, down, left, right '' '' horizontal, vertical, perpendicular, horizontal '' and '' top, bottom '' and the like indicated direction or positional relationship is usually based on the direction or positional relationship shown in the drawing, only for the convenience of describing the utility model and simplifying the description, in the case where no contrary statement is made, these direction words do not indicate and imply that the device or element indicated must have a particular orientation or be constructed and operated in a particular orientation, therefore it cannot be understood as the limitation of the protection scope of the utility model: the direction words '' inside, outside '' refer to the inside and outside relative to the contour of each component.

[0028] For the convenience of description, spatial relative terms such as '' above'', '' above'', '' upper surface'', '' upper '' and the like can be used here to describe the spatial position relationship of one device or feature with other devices or features as shown in the drawing. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawing. For example, if the device in the drawing is inverted, the device described as '' above '' or '' above '' other devices or structures will be positioned '' below '' or '' below '' other devices or structures. Thus, the exemplary term '' above '' can include both '' above '' and '' below ''. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative description used here is interpreted accordingly.

[0029] In addition, it needs to be explained that the use of '' first'', '' second '' and the like to limit parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, therefore it cannot be understood as the limitation of the protection scope of the utility model.

[0030] As shown in Figure 1 The utility model provides a kind of balance device of vertical pump suitable for high pressure and low head condition of entry, comprising: first stage flow guide shell 4, secondary impeller 5, last stage flow guide shell 6, bushing 9, suction section 10, first stage impeller 11, shaft 12, secondary flow guide shell 13, last stage impeller 14 and support tube 15;Last stage impeller 14, secondary impeller 5 and first stage impeller 11 are sequentially mounted on shaft 12 from top to bottom;The outside of each stage impeller is sequentially assembled support tube 15, last stage flow guide shell 6, secondary flow guide shell 13, first stage flow guide shell 4 and suction section 10 from top to bottom;Suction section 10 and shaft 12 are assembled with shaft bushing 9;The flow guide shell structure in the structure of the application is only a hydraulic structure part schematic, and the hydraulic structure part can be segmental guide vane structure or flow guide shell structure.

[0031] The balance box 8, the balance drum 2 and the balance sleeve 7 together form a balance device for balancing axial force of the pump, and the balance device is arranged at the bottom end of the pump, i.e. is arranged at the bottom end of the suction section 10 by means of screws.

[0032] The rear cavity of the balance drum 2 is connected with the outlet cavity of the pump by means of the balance pipe 3, and is equal to the outlet pressure; and the front cavity of the balance drum 2 is connected with the inlet of the pump, and is equal to the inlet pressure, so that the pressure of the rear cavity of the balance drum 2 is greater than the pressure of the front cavity, and the force receiving areas of the front and rear cavities of the balance drum 2 are equal, and finally the balance drum generates a vertical downward axial force which is in the same direction as the axial force of the water wheel hydraulic axial force, and the two together balance the vertical upward axial force generated by the high pressure of the inlet, so that the pump shaft is always in a slightly stretched state during the operation of the pump, and the operation reliability of the pump is ensured.

[0033] The balance device of the design is installed in the following manner: the balance box 8 is connected with the suction section 10 of the pump by means of screws; the balance sleeve 7 is connected with the balance box 8 by means of screws; the balance drum 2 is axially positioned by means of the stepped portion on the shaft 12 and the locking nut 1 at the end of the shaft; and the balance pipe 3 is installed on the balance box 8 and the support pipe 15.

[0034] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A balancing device for a vertical pump suitable for high inlet pressure and low head conditions, comprising: The impeller consists of a first-stage guide shell (4), a second-stage impeller (5), a last-stage guide shell (6), a bushing (9), an intake section (10), a first-stage impeller (11), a shaft (12), a second-stage guide shell (13), a last-stage impeller (14), and a support pipe (15). The last-stage impeller (14), the second-stage impeller (5), and the first-stage impeller (11) are mounted on the shaft (12) from top to bottom. The outer surfaces of each impeller are assembled from top to bottom with the support pipe (15), the last-stage guide shell (6), the second-stage guide shell (13), the first-stage guide shell (4), and the intake section (10). A bushing (9) is fitted between the intake section (10) and the shaft (12). Its characteristics are: The lower end of the inhalation section (10) is equipped with a balancing device consisting of a balancing box (8), a balancing sleeve (7), and a balancing drum (2).

2. The balancing device for a vertical pump applicable to high inlet pressure and low head conditions according to claim 1, characterized in that: The balance box (8) is bolted to the bottom of the suction section (10); The balance sleeve (7) is bolted to the inner wall of the balance box (8); The balance drum (2) is installed inside the balance sleeve (7) and mounted on the shaft (12).

3. The balancing device for a vertical pump applicable to high inlet pressure and low head conditions according to claim 1, characterized in that: The balance drum (2) is circumferentially positioned by the upper step of the shaft (12) and the locking nut (1) at the shaft end.

4. The balancing device for a vertical pump applicable to high inlet pressure and low head conditions according to claim 1, characterized in that: The balancing device is also equipped with a balancing tube (3); The bottom end of the balance tube (3) is connected to the interior of the balance box (8), and the top end is connected to the interior of the support tube (15).

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