Impeller structure with baffles at outlet parts of folded blades and vortex pump

Abstract

The utility model provides an impeller structure with baffles at outlet parts of folded blades and a vortex pump. The impeller structure comprises a rear cover plate, a plurality of folded blades on the front end face of the rear cover plate, a plurality of back blades on the rear end face of the rear cover plate, the baffles on the folded blades and a hub in the center of the rear cover plate. The folded blade comprises a long blade section and a short blade section which are connected with each other, the baffle plate is vertically arranged on a pressure surface and / or a suction surface of the short blade section, the width of the baffle plate is b0 = (1-2) t, the thickness of the baffle plate is t0 = (0.5-0.8) t, b0 is the width of the baffle plate, t0 is the thickness of the baffle plate, and t is the thickness of the folded blade. The baffle is arranged at the outlet part of the folded blade, so that fluid can be better guided to flow to the outlet, abrasion and blockage caused by the fact that a medium in a vaneless cavity flows into a blade channel are reduced, flow state disturbance and hydraulic loss of the blade channel are reduced, and the conveying efficiency of the vortex pump is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of open vortex pumps, in particular to an impeller structure with a baffle provided at the outlet of a folding blade and a vortex pump. Background Art

[0002] A swirl pump is a special type of centrifugal pump that works by conveying media based on swirl technology. It works by generating a rotating fluid motion inside the pump body. This motion results in low pressure in the middle of the vortex, allowing the medium to be continuously drawn in, and forming a high-energy circulation around the periphery, which is ultimately discharged from the pump chamber. This type of pump is typically used to convey media containing solids, especially those containing large solid particles, long solid fibers, or a high solid volume concentration. The swirl pump was developed to address the shortcomings of traditional centrifugal pumps in handling certain fluid media, such as those containing solid particles or high-viscosity liquids. Traditional centrifugal pumps may experience blockage or inefficiency when handling such fluids, while swirl pumps can convey these fluids more efficiently through swirl technology. The swirl pump's impeller design and pump body structure enable it to generate a high-speed rotating liquid flow, thereby more effectively conveying media containing solids.

[0003] However, although the swirl pump impeller has a simple structure, is easy to manufacture and has good non-clogging performance, when the impeller rotates, the energy of the medium increases under the action of centrifugal force, and it is easy to form a circulating flow in the bladeless cavity on one side of the impeller and then flow into the blade channel, causing wear and blockage, low energy conversion, large hydraulic loss, and low efficiency. Most efficiencies are below 60%, resulting in energy waste. Utility Model Content

[0004] In response to the problem of low transportation efficiency of solid media by vortex pumps, the utility model provides an impeller structure and a vortex pump with a baffle provided at the outlet part of the folded blade. By providing the baffle at the outlet part of the folded blade, the fluid can be better guided to flow to the outlet, reducing the wear and blockage caused by the medium in the bladeless cavity flowing into the blade channel, thereby reducing the disturbance of the flow state in the blade channel and the hydraulic loss, and improving the transportation efficiency of the vortex pump.

[0005] The utility model achieves the above technical objectives through the following technical means.

[0006] The impeller is provided with a baffle at the outlet of the folding blade, and the impeller adopts a semi-open impeller structure, the impeller comprising a rear cover, a plurality of folding blades on the front end surface of the rear cover, a plurality of back blades on the rear end surface of the rear cover, a baffle on the folding blade, and a hub at the center of the rear cover; the folding blade comprises a connected long blade segment and a short blade segment, the long blade segment rotates around its inlet end point A close to the impeller hub and forms a first angle of θ1 with the diameter of the rear cover passing through the end point A; the short blade segment rotates around its connection point with the long blade segment and forms a second angle of θ2 with the extension line of the long blade segment; the baffle is vertically installed on the pressure surface and / or suction surface of the short blade segment, the side of the baffle away from the rear cover is flush with the side of the short blade segment away from the rear cover, and the two ends of the baffle are respectively connected with the outlet end point B of the short blade segment and the connection point between the short blade segment and the long blade segment; the width and thickness of the baffle are:

[0007] b0= (1~2)t (1)

[0008] t0= (0.5~0.8)t (2)

[0009] Where b0 is the baffle width, t0 is the baffle thickness, and t is the folding blade thickness.

[0010] Furthermore, one end of the baffle close to the long blade section is in a rounded structure, and the rounded radius r=(0.8-1.2)b0.

[0011] Furthermore, the thickness t of the folding blade is 4 to 12 mm, and the inlet diameter D1, outlet diameter D2 and outlet width b1 of the folding blade are:

[0012]

[0013] b1=(0.15~0.21)D1 (5)

[0014] Among them, the coefficient K1 = 2 ~ 2.4, Q is the flow rate of the pump, the unit is m 3 / s, n is the impeller speed, unit is r / min, μ is the flow slip between the folded blades, η h is the hydraulic efficiency of the pump without baffles at the folding blade outlet, and H is the pump head without baffles at the folding blade outlet, in m.

[0015] Furthermore, the first angle θ1 is 15° to 60°, and the second angle θ2 is 30° to 60°.

[0016] Furthermore, the number of the folding blades is 8 to 12, and they are evenly distributed around the circumference on the front end surface of the rear cover.

[0017] Furthermore, the number and thickness of the back blades are consistent with those of the folding blades.

[0018] Furthermore, the ratio of the length of the short leaf segment to the length of the long leaf segment is 1:2.

[0019] Furthermore, the baffle is fixed to the folding blade by welding, or is integrally formed with the folding blade.

[0020] A vortex pump comprising the impeller structure described in any one of the above items.

[0021] Furthermore, a gap of 0.5 to 2 mm is left between the back blade and the pump housing.

[0022] The beneficial effects of the utility model are as follows:

[0023] 1. The impeller structure in the present invention can more effectively improve the fluid throughput rate when transporting solid-liquid two-phase flow, and adding a baffle at the blade outlet can effectively reduce the fluid flowing into the bladeless cavity on one side of the impeller and form a circulating flow, thereby reducing the wear and blockage caused by the medium in the bladeless cavity flowing into the blade channel, reducing the disturbance of the blade channel flow state and hydraulic loss, and improving the delivery efficiency of the swirl pump.

[0024] 2. The baffle in this invention is installed on the pressure and / or suction side of the short blade segment, preferably on the suction side. This minimizes the flow of fluid into the impeller's bladeless cavity and the resulting circulation flow. It also prevents the increased weight of the baffle from causing excessive load on the impeller, which in turn affects the impeller's lift and efficiency. The baffle's width and thickness are controlled based on the width of the folded blades. Ultimately, through the triple improvements in installation position, width, and thickness, the impeller's lift can be increased to a maximum of over 6.2 meters and its efficiency to over 60%.

[0025] 3. The baffle in the present invention has a rounded structure at one end close to the long blade section, which can not only effectively reduce the contact area between the solid medium, especially the flocs and the baffle, and avoid the entanglement of materials during transportation, thereby significantly reducing the risk of blockage caused by entanglement and improving the anti-entanglement performance, but also can improve the transportation efficiency to a certain extent and ensure the smooth passage of materials.

[0026] 4. The baffle in the utility model has the advantages of simple structure and easy processing. It can not only significantly improve the pump head efficiency during operation, but also protect the blades when conveying media containing solid particles, thereby increasing the service life of the impeller.

[0027] 5. Compared to conventional impellers installed in non-clogging pumps, the impeller in this utility model does not retract completely into the rear chamber, but rather remains at the rear of the pump chamber. This simple impeller structure makes it easy to manufacture, and most solids are delivered directly to the volute chamber without passing through the impeller. This provides excellent flowability and resistance to fiber entanglement, high efficiency, and stable and reliable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a front perspective view of the impeller structure with a baffle at the outlet of the folding blades described in the present invention.

[0029] Figure 2 This is a front view of the impeller structure with a baffle at the outlet of the folding blades described in the present invention.

[0030] Figure 3 This is a partial enlarged view of the baffle.

[0031] Figure 4 This is a three-dimensional back view of the impeller structure with a baffle at the outlet of the folding blades described in the present invention.

[0032] The reference numerals are as follows:

[0033] 1-rear cover; 2-folding blade; 21-long blade segment; 22-short blade segment; 3-back blade; 4-baffle; 5-hub. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0035] Example 1

[0036] The impeller structure with a baffle at the folding blade outlet of this embodiment adopts a semi-open impeller structure. The impeller includes a rear cover plate 1, 10 folding blades 2 evenly distributed around the circumference on the front end surface of the rear cover plate 1, 10 back blades 3 evenly distributed around the circumference on the rear end surface of the rear cover plate 1, baffles 4 on the folding blades 2, and a hub 5 at the center of the rear cover plate 1. The thickness t of the folding blades 2 is 0.004m. Figure 1 This is a front perspective view of the impeller structure with a baffle provided at the outlet portion of the folding blades described in this embodiment.

[0037] The folding blade 2 includes a long blade segment 21 and a short blade segment 22 connected to each other. The long blade segment 21 rotates around its inlet end point A close to the impeller hub 5 and forms a first angle of 30° with the diameter of the rear cover plate 1 passing through end point A. The short blade segment 22 rotates around its connection point with the long blade segment 21 and forms a second angle of 30° with the extension line of the long blade segment 21. The baffle 4 is welded and fixed vertically on the suction surface of the short blade segment 22. The side of the baffle 4 away from the rear cover plate 1 is flush with the side of the short blade segment 22 away from the rear cover plate 1, and the two ends of the baffle 4 are respectively connected to the outlet end point B of the short blade segment 22 and the connection point between the short blade segment 22 and the long blade segment 21. Figure 3 This is a partial enlarged view of the baffle. The width and thickness of the baffle 4 are:

[0038] b0= (1~2)t (1)

[0039] t0= (0.5~0.8)t (2)

[0040] Among them, b0 is the baffle width, unit is m, t0 is the baffle thickness, unit is m, t is the folding blade thickness, unit is m, here t0 is 0.002m.

[0041] The end of the baffle 4 close to the long blade section 21 is in a rounded structure; the radius of the rounding is r=(0.8-1.2)b0, where r=b0.

[0042] The ratio of the length of the short blade section 22 to the length of the long blade section 21 is 1:2. The inlet diameter D1 of the folding blade 2, the outlet diameter D2 of the folding blade 2 and the outlet width b1 of the folding blade 2 are:

[0043]

[0044] b1=(0.15~0.21)D1 (5)

[0045] Among them, the coefficient K1 = 2 ~ 2.4, Q is the flow rate of the pump, the unit is m 3 / s, n is the impeller speed, unit is r / min, μ is the flow slip between the folded blades, η h is the hydraulic efficiency of the pump without baffles at the folding blade outlet, H is the pump head without baffles at the folding blade outlet, in meters. In this embodiment, the total length of the folding blade is 0.0414m, D1 is 0.048m, D2 is 0.128m, b1 is 0.022m, Figure 2 This is a front view of the impeller structure with a baffle at the outlet of the folding blades described in the present invention.

[0046] In order to explore the influence of different baffle 4 widths b0 on the impeller head efficiency, the performance of the swirl pump with impellers equipped with baffles of different widths was calculated respectively, and the flow field simulation was performed using the numerical calculation software CFX. The external characteristic results are shown in Table 1 below.

[0047] Table 1 Effect of baffles of different widths on impeller head and efficiency

[0048] Lift (m) efficiency(%) Baffle width 0.003m 6.111 57.9 Baffle width 0.004m 6.238 60.1 Baffle width 0.006m 6.105 58.0 Baffle width 0.008m 6.076 55.3

[0049] Numerical simulations show that when b0 = 1.5t, baffle 4's improvement in impeller head efficiency is nearly maximized. Baffle 4 primarily serves to constrain the fluid, reducing the amount of non-cavity fluid entering the impeller flow passage from the back of the blades, improving the internal flow pattern of the impeller, and reducing flow losses. However, if the width of baffle 4 is too small, it will not effectively constrain the fluid, causing more cavity fluid to enter the impeller flow passage from the back of the blades, resulting in a turbulent flow pattern. However, if the width of baffle 4 is too large, it will also increase the load on the impeller, reducing the impeller's head and efficiency, making it unfavorable for conveying fluids containing particles and fibers.

[0050] Figure 4 This is a three-dimensional view of the back of the impeller structure with a baffle at the folding blade outlet part described in this embodiment. The 10 back blades 3 on the rear end surface of the rear cover plate 1 correspond one-to-one to the folding blades 2, and the thickness of the back blades 3 is equal to that of the folding blades 2.

[0051] This embodiment also relates to a vortex pump comprising the above-mentioned impeller structure, wherein a gap of 0.5 to 2 mm is left between the back blade 3 and the pump casing, and the impeller is not installed and retracted into the rear pump chamber, which has better anti-winding performance and can further improve the fluid flow state.

[0052] The impeller of this utility model has a simple structure and is easy to manufacture. It can transport media containing particles (such as granular metal, grain, silt, and wood blocks) and fibers (such as wood pulp, glass fiber, paper pulp, and hemp rope). Most solids are directly delivered to the volute without passing through the impeller, resulting in excellent flowability and resistance to fiber entanglement. The addition of a baffle 4 on the back of the blade outlet effectively blocks the circulating flow between the blades and prevents losses caused by secondary flow flowing from the front to the back of the blades, thereby further improving the flow pattern, increasing the pump head and efficiency, and ensuring smooth and reliable operation.

[0053] Example 2

[0054] The difference between this embodiment and embodiment 1 is that the number of baffles 4 is two and they are installed vertically on the suction and pressure surfaces of the short blade segment 22, respectively. The side of the baffle 4 away from the rear cover plate 1 is flush with the side of the short blade segment 22 away from the rear cover plate 1, and the two ends of the baffle 4 are connected to the outlet end point B of the short blade segment 22 and the connection point between the short blade segment 22 and the long blade segment 21, respectively. The cross-section of the two baffles 4 and the short blade segment 22 is "T" shaped. Apart from this, the specifications, shape, and other impeller structures of the baffles 4 are exactly the same as those of embodiment 1. In order to explore the influence of the presence or absence of baffles 4 and the installation position of baffles 4 on the impeller head efficiency, the performance of the impeller swirl pump with and without baffles 4 and with baffles 4 installed in different positions was calculated, and flow field simulation was performed using numerical calculation software CFX. The external characteristic results are shown in Table 2 below.

[0055] Table 2 The effect of baffle 4 on impeller lift and efficiency with or without baffle 4 and at different installation positions

[0056] Lift (m) efficiency(%) No bezel 4 5.933 56.8 Example 2 6.105 58.1 Example 1 6.238 60.1

[0057] Numerical simulations show that the impeller design with the baffle 4 at the blade outlet achieves the desired performance, achieving a lift compared to the impeller without the baffle 4. However, the added weight of the T-shaped baffle leads to excessive load on the impeller, which in turn affects the lift and efficiency of the impeller. Using a single baffle 4, as in Example 1, not only maximizes the lift and efficiency of the impeller, but also ensures that the impeller's inherent load does not affect its lift and efficiency.

[0058] The embodiments described are preferred implementations of the present invention, but the present invention is not limited to the above-mentioned implementations. Any obvious improvements, replacements or modifications that can be made by those skilled in the art without departing from the essential content of the present invention are within the scope of protection of the present invention.

Claims

1. An impeller structure with a baffle at the outlet of the folding blade, characterized in that: The impeller adopts a semi-open impeller structure, comprising a rear cover (1), a plurality of folded blades (2) on the front end surface of the rear cover (1), a plurality of back blades (3) on the rear end surface of the rear cover (1), a baffle (4) on the folded blades (2), and a hub (5) at the center of the rear cover (1); the folded blades (2) comprise connected long blade segments (21) and short blade segments (22); the long blade segments (21) rotate around their inlet end point A close to the impeller hub (5) and form a first clamping angle of θ1 with the diameter of the rear cover (1) passing through the end point A. Angle; the short blade segment (22) rotates around the connection point between it and the long blade segment (21) and forms a second angle of angle θ2 with the extension line of the long blade segment (21); the baffle (4) is vertically installed on the pressure surface and / or suction surface of the short blade segment (22), the side of the baffle (4) away from the rear cover (1) is flush with the side of the short blade segment (22) away from the rear cover (1), and the two ends of the baffle (4) are respectively connected with the outlet end point B of the short blade segment (22) and the connection point between the short blade segment (22) and the long blade segment (21); the width and thickness of the baffle (4) are: b0=(1~2)t (1) t0=(0.5~0.8)t (2) Wherein, b0 is the width of the baffle, in m, t0 is the thickness of the baffle, in m, and t is the thickness of the folding blade, in m.

2. The impeller structure with a baffle at the outlet of the folding blade according to claim 1, characterized in that: One end of the baffle (4) close to the long blade section (21) is in a rounded structure, and the rounded radius r=(0.8-1.2)b0.

3. The impeller structure with a baffle at the outlet of the folding blade according to claim 1, characterized in that: The thickness t of the folding blade (2) is 4 to 12 mm, and the inlet diameter D1 of the folding blade (2), the outlet diameter D2 of the folding blade (2) and the outlet width b1 of the folding blade (2) are: b1=(0.15~0.21)D1 (5) Among them, the coefficient K1 = 2 ~ 2.4, Q is the flow rate of the pump, the unit is m 3 / s, n is the impeller speed, unit is r / min, μ is the flow slip between the folded blades, η h is the hydraulic efficiency of the pump without baffles at the folding blade outlet, and H is the pump head without baffles at the folding blade outlet, in m.

4. The impeller structure with a baffle at the outlet of the folding blade according to claim 1, characterized in that: The first angle θ1 is between 15° and 60°, and the second angle θ2 is between 30° and 60°.

5. The impeller structure with a baffle at the outlet of the folding blade according to claim 1, characterized in that: The number of the folding blades (2) is 8 to 12, and they are evenly distributed around the circumference on the front end surface of the rear cover plate (1).

6. The impeller structure with a baffle at the outlet of the folding blade according to claim 1, characterized in that: The number and thickness of the back blades (3) are consistent with those of the folding blades (2).

7. The impeller structure with a baffle at the outlet of the folding blade according to claim 1, characterized in that: The length ratio of the short leaf segment (22) to the long leaf segment (21) is 1:

2.

8. The impeller structure with a baffle at the outlet of the folding blade according to claim 1, characterized in that: The baffle (4) is welded and fixed on the folding blade (2), or is integrally formed with the folding blade (2).

9. A vortex pump, characterized in that: An impeller structure comprising a baffle provided at the outlet portion of the folded blade according to any one of claims 1 to 8.

10. The vortex pump according to claim 9, characterized in that A gap of 0.5 to 2 mm is left between the back blade (3) and the pump housing.

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