Centrifugal pump impeller capable of operating in wide range

Abstract

The invention provides a centrifugal pump impeller capable of operating in a wide range, which comprises a front cover plate and a rear cover plate, and a plurality of blades are arranged between the front cover plate and the rear cover plate; the impeller is characterized in that at least one blade is a rotatable blade, and index plates installed on the front cover plate and the rear cover plate are arranged at the two ends of the rotatable blade respectively; the index plates at the two ends are connected to the front cover plate and the rear cover plate in a clamped mode through fixing clamping pieces correspondingly. The index plates at different positions are clamped through the fixing clamping pieces so that the angles of the rotatable blades can be changed. By changing the angles of the rotatable blades, the operation range of the centrifugal pump is widened, and the cost for replacing the impeller is reduced.

Description

Technical Field

[0001] The invention relates to the field of fluid machinery, and in particular to a centrifugal pump impeller capable of operating over a wide range. Background Art

[0002] A pump is a machine for conveying fluid or pressurizing fluid. It transfers the mechanical energy of the prime mover or other external energy to the liquid, increasing the energy of the liquid. Pumps are mainly used to convey liquids such as water, oil, acid and alkali liquids, emulsions, suspensions and liquid metals. They can also convey liquid-gas mixtures and liquids containing suspended solids. Pumps are divided into centrifugal pumps, mixed flow pumps and axial (throughflow) flow pumps according to the size of the specific speed. After the centrifugal pump impeller is designed, its corresponding hydraulic performance is determined. After the centrifugal pump has been running for a short time, the blades are damaged due to various reasons such as cavitation. The cost of replacing a new impeller is high and the disassembly is cumbersome. In response to this problem, the patent of the present invention proposes a wide-range operation centrifugal pump impeller with the function of quick blade disassembly and adjustable angle, which greatly expands the operating range of the centrifugal pump.

[0003] There are two patents in the prior art: ZL201710354187.9 Centrifugal pump or fan impeller with adjustable blades, and ZL 202110369048.X Centrifugal pump impeller with adjustable blade outlet angle. Both patents use deformable blades. The former fixes the position of the blades near the outlet edge, and the latter fixes the position of the blades near the inlet edge, and changes the blade angle by bending and twisting the blades. The problems with both are:

[0004] (1) Only the local blades can be adjusted at a small angle, and the range of centrifugal pump operating conditions is limited;

[0005] (2) The blades are usually made of metal, and frequent bending and twisting of the blades can easily lead to fatigue fracture;

[0006] (3) The blade adjustment method is cumbersome and the blades cannot be adjusted or replaced quickly. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a centrifugal pump impeller capable of operating over a wide range, which increases the operating range of the centrifugal pump and reduces the cost of replacing the impeller by changing the angle of rotatable blades.

[0008] The present invention achieves the above technical objectives through the following technical means.

[0009] A centrifugal pump impeller capable of wide-range operation comprises a front cover plate and a rear cover plate, with a plurality of blades arranged between the front cover plate and the rear cover plate; the invention is characterized in that at least one of the blades is a rotatable blade, and both ends of the rotatable blade are respectively provided with dividing plates mounted on the front cover plate and the rear cover plate; the dividing plates at both ends are respectively clamped on the front cover plate and the rear cover plate by fixing cards; the dividing plates at different positions are clamped by fixing cards to change the angle of the rotatable blade.

[0010] Furthermore, the front cover plate and the rear cover plate are provided with open T-shaped step slots, and the dividing plate is connected to the step slots by fixing cards.

[0011] Furthermore, indexing plates are installed at both ends of the rotatable blades through a rotating shaft, and a plurality of indexing grooves are evenly distributed on the indexing plate, and one of the indexing grooves is connected to a fixed card.

[0012] Furthermore, the fixed card includes an upper card plate and a lower card plate, one end of the upper card plate is provided with a first arc groove, the first arc groove is provided with a graduation positioning key with a protruding arc surface, which is used to position the dividing plate; the lower card plate is located below the upper card plate, one end of the lower card plate protrudes with a first arc groove, the upper card plate and the lower card plate constitute a T-shaped card, and the T-shaped card matches the step card slot.

[0013] Furthermore, one end of the lower clamping plate protruding from the first arc-shaped groove is provided with a second arc-shaped groove, and the second arc-shaped groove is used to support the rotating shaft.

[0014] Furthermore, the blade shapes of the plurality of rotatable blades are the same or different, and the blade shapes of the rotatable blades are straight blades, forward curved blades, or backward curved blades.

[0015] Furthermore, the trajectory formed by one rotation of the rotatable blades shall not exceed the intersection of the straight line and the arc on the rear cover plate, and shall not exceed the outlet edge of the impeller; the inlet edge and the outlet edge of the rotatable blades are both rounded.

[0016] Furthermore, the outline size of the T-shaped card matches the outline size of the step card slot, so that the T-shaped card is completely embedded in the front cover plate or the rear cover plate.

[0017] A centrifugal pump comprises the centrifugal pump impeller capable of operating over a wide range.

[0018] The beneficial effects of the present invention are:

[0019] 1. The centrifugal pump impeller capable of wide-range operation described in the present invention adjusts the blades by rotating the dividing plate, thereby achieving arbitrary adjustment of the blade angle, thereby adjusting the hydraulic performance and operating conditions of the water pump, greatly broadening the operating range of the centrifugal pump.

[0020] 2. The centrifugal pump impeller capable of wide-range operation described in the present invention can improve local losses and pressure pulsations of the centrifugal pump, improve operational stability, and realize stability adjustment of the centrifugal pump by adjusting the angle of a single or multiple rotatable blades.

[0021] 3. The centrifugal pump impeller capable of wide-range operation described in the present invention facilitates blade replacement. After the pump has been running for a certain period of time, the blades may be worn and cavitated, causing the pump performance to be greatly reduced. It is only necessary to remove the pump cover, fix the card sheet, and replace the rotatable blades with new ones, thereby reducing maintenance costs and improving maintenance efficiency.

[0022] 4. The centrifugal pump impeller capable of wide-range operation described in the present invention generally has 3-9 rotatable blades, and may use one or more straight blades, forward curved blades, or backward curved blades, thereby broadening the limitations of impellers with single blade forms and further broadening the application scenarios in actual engineering applications to meet a variety of working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings described below are some embodiments of the present invention. For ordinary technicians in this field, it is obvious that other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a schematic diagram of a centrifugal pump impeller capable of operating over a wide range as described in the present invention.

[0025] Figure 2 for Figure 1 AA section view.

[0026] Figure 3 It is a three-dimensional diagram of the front cover plate and the rear cover plate described in the present invention.

[0027] Figure 4 This is an assembly diagram of the rotatable blades and indexing plate described in the present invention.

[0028] Figure 5 This is an axial view of the fixed card described in the present invention.

[0029] Figure 6 The figures are the front view and top view of the fixed card of the present invention.

[0030] Figure 7 A schematic diagram of blade angle change provided in an embodiment of the present invention.

[0031] In the figure:

[0032] 1-front cover; 11-step card slot; 2-fixing card; 21-mounting hole; 22-indexing positioning key; 23-lower card plate; 24-upper card plate; 3-indexing plate; 4-rotatable blades; 5-rear cover; 6-rotating shaft; 7-fixing screw. DETAILED DESCRIPTION

[0033] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0035] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] like Figure 1 and Figure 2As shown, the centrifugal pump impeller capable of wide-range operation described in the present invention comprises a front cover plate 1 and a rear cover plate 5, and a plurality of blades are arranged between the front cover plate 1 and the rear cover plate 5; at least one blade is a rotatable blade 4, and both ends of the rotatable blade 4 are respectively provided with a dividing plate 3 installed on the front cover plate 1 and the rear cover plate 5; the dividing plates 3 at both ends are respectively connected to the front cover plate 1 and the rear cover plate 5 by a fixing card 2; the dividing plates 3 at different positions are connected by the fixing card 2 to change the angle of the rotatable blade 4. By removing the fixing card 2, the angle of the dividing plate 3 is changed to achieve arbitrary adjustment of the blade angle, thereby achieving the purpose of adjusting the working condition of the water pump.

[0037] like Figure 3 The front cover plate 1 and the rear cover plate 5 are provided with an open T-shaped step slot 11, and the indexing plate 3 is connected to the step slot 11 through a fixing card 2. The fixing card 2 is installed in the threaded hole of the T-shaped step slot 11 through a fixing screw 7. The open T-shaped step slot 11 can facilitate the quick disassembly of the fixing card 2 and the adjustment of the angle of the rotatable blade 4.

[0038] like Figure 4 As shown, the dividing plate 3 is installed at both ends of the rotatable blade 4 through the rotating shaft 6, and a plurality of dividing grooves are evenly distributed on the dividing plate 3 along the circumferential direction, and one of the dividing grooves is connected to the fixed card 2. The outer diameter of the rotating shaft 6 is smaller than the root of the dividing groove to prevent mutual interference, and the strength requirements should be met. In the embodiment, in order to achieve the purpose of blade rotation angle division, the angle is divided every 18°, and 20 dividing groove positions can be provided, which are located at 18°, 36°, 54°, ..., 342° respectively. In actual engineering applications, the angle can be divided as needed, that is, the angle adjustment accuracy is changed by increasing or reducing the number of dividing grooves, thereby achieving the working condition adjustment accuracy.

[0039] like Figure 5 and Figure 6 As shown, the fixed card 2 includes an upper card plate 24 and a lower card plate 23. One end of the upper card plate 24 is provided with a first arc groove, and the first arc groove is provided with a graduated positioning key 22 with a protruding arc surface, which is used to position the indexing plate 3; the lower card plate 23 is located below the upper card plate 24, and one end of the lower card plate 23 protrudes the first arc groove. The upper card plate 24 and the lower card plate 23 form a T-shaped card, and the T-shaped card matches the step card groove 11. The outline size of the T-shaped card matches the outline size of the step card groove 11, so that the T-shaped card is completely embedded in the front cover plate 1 or the rear cover plate 5. It can be seen from the figure that the step height of the T-shaped card is consistent with the depth of the step card groove 11, so that the fixed card 2 does not protrude from the front cover plate or the rear cover plate, reducing hydraulic loss. One end of the lower card plate 23 protruding the first arc groove is provided with a second arc groove, and the second arc groove and the step card groove 11 are used to support the rotating shaft 6.

[0040] The rotatable blades 4 are straight blades, forward curved blades or backward curved blades, and the number of blades between the front cover plate 1 and the rear cover plate 5 is 3-9. In the case where the impeller is equipped with multiple rotatable blades 4, any one of the rotatable blades 4 or all of the rotatable blades 4 can be replaced with one of the forms such as straight blades, forward curved blades, and backward curved blades to meet the actual working conditions and application requirements. The trajectory formed by the rotatable blades 4 rotating one circle shall not exceed the intersection of the straight line and the arc on the rear cover plate 5, and shall not exceed the outlet edge of the impeller; the inlet edge and the outlet edge of the rotatable blade 4 are both rounded to ensure a stable transition of the fluid and reduce hydraulic losses.

[0041] In the case of multiple rotatable blades 4, the angle of any one or all of the rotatable blades 4 can be adjusted to meet actual needs. After a certain period of operation, when the impeller is worn, cavitated, etc. and needs to be replaced with a new impeller, it is only necessary to remove the pump cover and the fixing card 2 and replace the new rotatable blade 4.

[0042] The rotatable blade 4 is installed between the front cover plate 1 and the rear cover plate 5. The front cover plate 1 and the rear cover plate 5 are provided with a step slot 11, which cooperates with the indexing plate 3 to press the rotatable blade 4 and limit the axial displacement. The height of the step slot 11 is consistent with the fixed card 2 to achieve flow channel filling. The step slot 11 is provided with a non-through mounting hole 21. The fixing screw 7 installs the fixed card 2 on the front cover plate 1 or the rear cover plate 5, which can restrict the radial movement of the rotatable blade 4 and reduce the hydraulic loss.

[0043] In the case of multiple rotatable blades 4, the angle of any one or all of the rotatable blades 4 can be adjusted to meet actual needs. Or any one or all of the rotatable blades 4 can be replaced with a straight blade, a forward curved blade, a backward curved blade, etc. to meet actual working conditions and application requirements.

[0044] like Figure 7 As shown, a centrifugal pump impeller is used as an example for calculation, and the flow rate is 400m 3 / h, speed 1450rpm, outer diameter 268mm, blade outlet angle design 20 degrees, volume loss, hydraulic loss and other coefficients estimated 0.9, assuming no pre-swirl at the inlet, according to the pump head formula H = U2V u2 / g, the theoretical head value is 24.8m. If the blade outlet angle is 60 degrees by rotating the blades, the theoretical head of the water pump is 32.5m; if the blade outlet angle is 10 degrees by rotating the blades, the theoretical head of the water pump is 12.5m. In addition, the blade rotation angle can be 0 to 360 degrees, that is, any circumferential rotation angle, which can achieve a wider operating range. Therefore, the centrifugal pump impeller that can operate in a wide range of the present invention can change the head size according to the load requirements. For example, when the load requires a large head, the blades are rotated to a blade outlet angle of 60 degrees; if the load requires a small head, the blades are rotated to a blade outlet angle of 10 degrees.

[0045] The centrifugal pump of the present invention comprises the centrifugal pump impeller capable of operating over a wide range.

[0046] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0047] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A centrifugal pump impeller capable of wide range operation, comprising a front cover plate (1) and a rear cover plate (5), wherein a plurality of blades are arranged between the front cover plate (1) and the rear cover plate (5); characterized in that: At least one of the blades is a rotatable blade (4); both ends of the rotatable blade (4) are provided with indexing plates (3) mounted on the front cover plate (1) and the rear cover plate (5); the indexing plates (3) at both ends are respectively clamped on the front cover plate (1) and the rear cover plate (5) via fixing cards (2); and the indexing plates (3) at different positions are clamped via the fixing cards (2) to change the angle of the rotatable blade (4).

2. The centrifugal pump impeller capable of wide range operation according to claim 1, characterized in that: The front cover plate (1) and the rear cover plate (5) are provided with an open T-shaped step slot (11), and the indexing plate (3) is clamped on the step slot (11) via a fixing card (2).

3. The centrifugal pump impeller capable of wide range operation according to claim 1, characterized in that: The two ends of the rotatable blade (4) are mounted with a dividing plate (3) via a rotating shaft (6); a plurality of dividing grooves are evenly distributed on the dividing plate (3), and one of the dividing grooves is connected to a fixed card (2).

4. The centrifugal pump impeller capable of wide range operation according to claim 2, characterized in that: The fixed card (2) comprises an upper card plate (24) and a lower card plate (23); a first arc-shaped groove is provided at one end of the upper card plate (24); a graduation positioning key (22) with a protruding arc surface is provided on the first arc-shaped groove for positioning the graduation plate (3); the lower card plate (23) is located below the upper card plate (24); a first arc-shaped groove is protruding at one end of the lower card plate (23); the upper card plate (24) and the lower card plate (23) form a T-shaped card, and the T-shaped card matches the step card slot (11).

5. The centrifugal pump impeller capable of wide range operation according to claim 4, characterized in that: One end of the lower clamping plate (23) protruding from the first arc-shaped groove is provided with a second arc-shaped groove, and the second arc-shaped groove is used to support the rotating shaft (6).

6. The centrifugal pump impeller capable of operating over a wide range according to claim 1, characterized in that: The blade shapes of the plurality of rotatable blades (4) are the same or different, and the blade shapes of the rotatable blades (4) are straight blades, forward curved blades, or backward curved blades.

7. The centrifugal pump impeller capable of operating over a wide range according to claim 1, characterized in that: The track formed by the rotatable blade (4) rotating one circle shall not exceed the intersection of the straight line and the arc on the rear cover plate (5), and shall not exceed the outlet edge of the impeller; the inlet edge and the outlet edge of the rotatable blade (4) are both rounded.

8. The centrifugal pump impeller capable of operating over a wide range according to claim 4, characterized in that: The outline size of the T-shaped card matches the outline size of the step card slot (11), so that the T-shaped card is completely embedded in the front cover plate (1) or the rear cover plate (5).

9. A centrifugal pump, characterized in that: The invention comprises a centrifugal pump impeller capable of operating over a wide range as described in any one of claims 1 to 8.

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