Centrifugal pump with double spiral blades and double-roller type granulator using centrifugal pump

Abstract

According to the centrifugal pump with the double-spiral blades and the double-roller type granulator using the centrifugal pump, the double-spiral blades are adopted, and the first blade and the second blade influence and balance each other; the contour line of the working surface of the first blade is an Archimedes spiral, and the contour line of the back surface of the second blade is a logarithmic spiral; the contour line of the back face of the first blade comprises a part of a first equal-pitch spiral line close to the inlet side and a part of a first variable-pitch spiral line away from the inlet side, and the contour line of the working face of the second blade comprises a part of a second variable-pitch spiral line close to the inlet side and a part of a second equal-pitch spiral line away from the inlet side. According to the spiral vane pump, the instability of fluid in the spiral vane pump can be optimized, vibration and noise are reduced, the second vane is equivalent to supplement of the first vane, cavitation and cavitation are effectively reduced, and the hydraulic efficiency and the stable performance of the centrifugal pump are improved to a certain degree.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid machinery, in particular to a centrifugal pump, and more particularly to a centrifugal pump with double helical blades and a double-roller granulator using the same. Background Art

[0002] In existing fluid machinery, single-screw vane pumps are prone to instability, vibration, and noise problems, which affect overall efficiency. Traditional single-screw vane pumps do not perform well when dealing with complex working conditions, which limits their scope of application, especially when applied to the fertilizer production process in the roller granulation industry. As the core component of the humidification spray system, the tightness of the synergistic effect of spraying and granulation directly affects the agglomeration effect between powder particles, the density and particle size distribution of the particles, etc. It can be seen that the centrifugal pump, as the main component of the spray, directly affects the quality and efficiency of granulation. An efficient and stable centrifugal pump can effectively solve problems such as insufficient flow control accuracy, transportation difficulties, leakage and pollution, maintenance and life. Therefore, it is particularly important to develop a centrifugal pump with high efficiency and low noise, and use it in the roller granulator to solve the above problems.

[0003] Prior art CN106382249A discloses a supercavitation centrifugal pump spiral impeller, which mainly consists of blades, an impeller front cover plate, and an impeller rear cover plate. The blades are fixedly connected between the impeller front cover plate and the impeller rear cover plate. The blades are spiral single blades. A groove is provided on the back of the spiral single blade near the suction port. When the supercavitation pump is running, an initial cavity is formed at the groove, and the initial cavity can form a stable supercavitation along the back of the blade. The supercavitation completely covers the back of the blade, so that the blades in the impeller are protected from cavitation corrosion under high-speed operation, and the blades are protected from wear, damage, destruction or bubbles caused by solid particles during operation.

[0004] However, the above structure has design limitations, and in the actual application of the centrifugal pump, there are still problems of instability, vibration and noise. Therefore, to address these problems, the applicant proposes a centrifugal pump with double helical blades and a double-roller granulator using the same. Summary of the Invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a centrifugal pump with double helical blades and a double-roller granulator using the same.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A centrifugal pump with double helical blades, comprising a centrifugal impeller, wherein the centrifugal impeller comprises blades, an impeller upper cover plate, and an impeller lower cover plate, wherein the blades are fixedly connected to the impeller upper cover plate and the impeller lower cover plate; the pump is characterized in that the blades comprise a first blade and a second blade, the first blade comprises a first blade working surface and a first blade back surface, the second blade comprises a second blade working surface and a second blade back surface, and both the first blade and the second blade are spiral blades; wherein the contour line of the first blade working surface is a portion of an Archimedean spiral, and the contour line of the second blade back surface is a portion of a logarithmic spiral; the diameter of the first blade suction port is D1, and the diameter of the second blade suction port is D2, wherein D1<D2<1.5D1.

[0008] Furthermore, the contour line of the back surface of the first blade includes a portion of the first equal-pitch helix close to the inlet side and a portion of the first variable-pitch helix away from the inlet side.

[0009] Furthermore, the angle between the point on the first equal-pitch helix and the starting point of the contour line on the back of the first blade is θ1, where 0°≤θ1<30°; the angle between the point on the first variable-pitch helix and the starting point of the contour line on the back of the first blade is θ2, where 30°≤θ2<300°.

[0010] Furthermore, the contour line of the second blade working surface includes a portion of the second variable-pitch helix close to the inlet side and a portion of the second constant-pitch helix away from the inlet side.

[0011] Furthermore, the angle between the point on the second variable pitch helix and the starting point of the contour line of the second blade working surface is θ3, where 0°≤θ3<20°; the angle between the point on the second equal pitch helix and the starting point of the contour line of the second blade working surface is θ4, where 20°≤θ4<180°.

[0012] Furthermore, the placement angle of the first blade inlet is β1, and the placement angle of the second blade inlet is β2, wherein β1+β2=180°.

[0013] Furthermore, the placement angle of the first blade outlet is β3, and the placement angle of the second blade outlet is β4, wherein β3+β4=90°.

[0014] Furthermore, the leading edge and the trailing edge of the first blade are both arc-shaped, and the leading edge and the trailing edge of the second blade are both sharp-pointed.

[0015] Furthermore, the included angle between the trailing edge of the first blade and the trailing edge of the second blade is θ, wherein 60°≤θ<120°.

[0016] Furthermore, the first blade working surface and the second blade working surface are evenly provided with a plurality of twisted leaflets along the flow path direction.

[0017] Furthermore, the inlet end of the second blade is arranged to protrude from the impeller upper cover plate in the axial direction.

[0018] A double-roll granulator includes a humidifying spray system and a control system; the humidifying spray system is characterized in that the multimodal nozzle is integrated with the multimodal nozzle, which is connected to a centrifugal pump, and the multimodal nozzle includes a high-pressure fan-shaped nozzle structure and a low-pressure conical spray structure; the control system adopts an AI algorithm module to dynamically optimize the spray pattern through a machine learning model; the centrifugal pump adopts a centrifugal pump with double helical blades.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. Conventional single-helical vane pumps in the prior art are prone to large instability and vibration noise when running at high speed, affecting the overall efficiency. To address the above problems, the present invention adopts double helical blades. The first blade and the second blade influence and balance each other, which can optimize the instability of the fluid in the helical vane pump and reduce the occurrence of vibration and noise. In addition, the second blade in the present invention is equivalent to a supplement to the first blade, effectively reducing the occurrence of cavitation and cavitation, and improving the hydraulic efficiency and stability performance of the centrifugal pump to a certain extent.

[0021] 2. The conventional single-helical vane pump blades in the prior art have a relatively simple shape design, and the single shape directly affects the flow state of the flow path and the service life of the blades. Based on this, the present invention further optimizes the contour structure of the blades, and optimizes the flow path in a multi-shape auxiliary manner to reduce the wear of the blades. Specifically, the contour line of the working surface of the first blade is a part of the Archimedean spiral, and the contour line of the back of the second blade is a part of the logarithmic spiral; the diameter of the suction port of the first blade is D1, and the diameter of the suction port of the second blade is D2, wherein D1<D2<1.5D1, the contour line of the back of the first blade includes a part of the first equal-pitch spiral close to the inlet side and a part of the first variable-pitch spiral away from the inlet side, and the contour line of the working surface of the second blade includes a part of the second variable-pitch spiral close to the inlet side and a part of the second equal-pitch spiral away from the inlet side.

[0022] 3. The mutual structure between the first blade and the second blade directly affects the efficiency and stability of the centrifugal pump. The present invention focuses on optimizing the associated fusion size and structure between the first blade and the second blade. For example, the inlet placement angle of the first blade is β1, and the inlet placement angle of the second blade is β2, where β1+β2=180°; the outlet placement angle of the first blade is β3, and the outlet placement angle of the second blade is β4, where β3+β4=90°; the leading edge and trailing edge of the first blade are both arc-shaped, and the leading edge and trailing edge of the second blade are both sharp-pointed; the angle between the trailing edge of the first blade and the trailing edge of the second blade is θ, where 60°≤θ<120°. The above-mentioned optimized design makes the correlation between the double helical blades greater, which is conducive to reducing the occurrence of noise and vibration.

[0023] 4. The flow path effect of the working surface directly determines the pumping performance of the centrifugal pump. In the present invention, the first blade working surface and the second blade working surface are evenly provided with multiple twisted leaflets along the flow path direction, which also improves the pumping performance.

[0024] 5. The inlet end of the second blade is axially protruding from the impeller cover plate. The above arrangement enables the second blade to also function as a guide vane, making the flow pattern at the blade inlet more stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a double-roll granulator in the prior art;

[0026] Figure 2 Schematic diagram of the axial cross section of the double helical blade impeller of the present invention;

[0027] Figure 3 Schematic diagram of the radial cross section of the double helical blade impeller of the present invention Figure 1 ;

[0028] Figure 4 Schematic diagram of the radial cross section of the double helical blade impeller of the present invention Figure 2 .

[0029] In the figure: blade 1, impeller upper cover plate 2, impeller lower cover plate 3, first blade working surface 4, first blade back surface 5, second blade working surface 6, second blade back surface 7, first blade 8, second blade 9, leaflet 10, first equal pitch helix 51, first variable pitch helix 52, second variable pitch helix 61, second equal pitch helix 62, first blade suction port diameter D1, second blade suction port diameter D2, angle θ1 between the point on the first equal pitch helix 51 and the starting point of the contour line of the first blade back surface 5 ... The angle θ2 of a point on the pitch helix 52 relative to the starting point of the contour line of the back side 5 of the first blade, the angle θ3 of a point on the second variable pitch helix 61 relative to the starting point of the contour line of the second blade working surface 6, the angle θ4 of a point on the second equal pitch helix 62 relative to the starting point of the contour line of the second blade working surface 6, the inlet placement angle β1 of the first blade 8, the inlet placement angle β2 of the second blade 9, the outlet placement angle β3 of the first blade 8, the outlet placement angle β4 of the second blade 9, and the angle θ between the trailing edge of the first blade 8 and the trailing edge of the second blade 9. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] The present invention will be described in further detail below with reference to the accompanying drawings.

[0032] like Figure 1-4 As shown, a centrifugal pump with double helical blades includes a centrifugal impeller, the centrifugal impeller includes a blade 1, an impeller upper cover plate 2, and an impeller lower cover plate 3, and the blade 1 is fixedly connected to the impeller upper cover plate 2 and the impeller lower cover plate 3; the characteristic is that: the blade 1 is composed of a first blade 8 and a second blade 9, the first blade 8 includes a first blade working surface 4 and a first blade back surface 5, the second blade 9 includes a second blade working surface 6 and a second blade back surface 7, and the first blade 8 and the second blade 9 are both spiral blades; the contour line of the first blade working surface 4 is a part of the Archimedean spiral, and the contour line of the second blade back surface 7 is a part of the logarithmic spiral; the diameter of the suction port of the first blade 8 is D1, and the diameter of the suction port of the second blade 9 is D2, wherein D1<D2<1.5D1.

[0033] Furthermore, the contour line of the back surface of the first blade 5 includes a portion of the first equal-pitch helix 51 close to the inlet side and a portion of the first variable-pitch helix 52 away from the inlet side.

[0034] Furthermore, the angle between the point on the first equal-pitch helix 51 and the starting point of the contour line of the back side 5 of the first blade is θ1, where 0°≤θ1<30°; the angle between the point on the first variable-pitch helix 52 and the starting point of the contour line of the back side 5 of the first blade is θ2, where 30°≤θ2<300°.

[0035] Furthermore, the contour line of the second blade working surface 6 includes a portion of the second variable-pitch helix 61 close to the inlet side and a portion of the second equal-pitch helix 62 away from the inlet side.

[0036] Furthermore, the angle between the point on the second variable pitch helix 61 and the starting point of the contour line of the second blade working surface 6 is θ3, where 0°≤θ3<20°; the angle between the point on the second equal pitch helix 62 and the starting point of the contour line of the second blade working surface 6 is θ4, where 20°≤θ4<180°.

[0037] Furthermore, the inlet placement angle of the first blade 8 is β1, and the inlet placement angle of the second blade 9 is β2, wherein β1+β2=180°.

[0038] Furthermore, the outlet placement angle of the first blade 8 is β3, and the outlet placement angle of the second blade 9 is β4, wherein β3+β4=90°.

[0039] Furthermore, the leading edge and the trailing edge of the first blade 8 are both arc-shaped, and the leading edge and the trailing edge of the second blade 9 are both sharp-pointed.

[0040] Furthermore, the angle between the trailing edge of the first blade 8 and the trailing edge of the second blade 9 is θ, wherein 60°≤θ<120°.

[0041] Furthermore, the first blade working surface 4 and the second blade working surface 6 are evenly provided with a plurality of twisted leaflets 10 along the flow path direction.

[0042] Furthermore, the inlet end of the second blade 9 is arranged to protrude from the impeller upper cover plate 2 in the axial direction.

[0043] A double-roll granulator includes a humidifying spray system and a control system; the humidifying spray system is characterized in that the multimodal nozzle is integrated with the multimodal nozzle, which is connected to a centrifugal pump, and the multimodal nozzle includes a high-pressure fan-shaped nozzle structure and a low-pressure conical spray structure; the control system adopts an AI algorithm module to dynamically optimize the spray pattern through a machine learning model; the centrifugal pump adopts a centrifugal pump with double helical blades.

[0044] Conventional single helical vane pumps in the prior art are prone to large instability and vibration noise when running at high speed, affecting the overall efficiency. To address the above problems, the present invention adopts double helical blades. The first blade and the second blade influence and balance each other, which can optimize the instability of the fluid in the helical vane pump and reduce the occurrence of vibration and noise. The second blade in the present invention is equivalent to a supplement to the first blade, effectively reducing the occurrence of cavitation and cavitation, and improving the hydraulic efficiency and stability performance of the centrifugal pump to a certain extent.

[0045] In the prior art, the shape design of the blades of conventional single-helical vane pumps is relatively simple, and the single shape directly affects the flow state of the flow path and the service life of the blades. Based on this, the present invention further optimizes the contour structure of the blades, and optimizes the flow path in a multi-shape auxiliary manner to reduce the wear of the blades. Specifically, the contour line of the working surface of the first blade is a part of the Archimedean spiral, and the contour line of the back of the second blade is a part of the logarithmic spiral; the diameter of the suction port of the first blade is D1, and the diameter of the suction port of the second blade is D2, wherein D1<D2<1.5D1, the contour line of the back of the first blade includes a part of the first equal-pitch spiral close to the inlet side and a part of the first variable-pitch spiral away from the inlet side, and the contour line of the working surface of the second blade includes a part of the second variable-pitch spiral close to the inlet side and a part of the second equal-pitch spiral away from the inlet side.

[0046] The mutual structure between the first blade and the second blade directly affects the efficiency and stability of the centrifugal pump. The present invention focuses on optimizing the associated fusion size and structure between the first blade and the second blade. For example, the inlet placement angle of the first blade is β1, and the inlet placement angle of the second blade is β2, where β1+β2=180°; the outlet placement angle of the first blade is β3, and the outlet placement angle of the second blade is β4, where β3+β4=90°; the leading edge and the trailing edge of the first blade are both arc-shaped, and the leading edge and the trailing edge of the second blade are both sharp-pointed; the angle between the trailing edge of the first blade and the trailing edge of the second blade is θ, where 60°≤θ<120°. The above-mentioned optimized design makes the correlation between the double helical blades greater, which is conducive to reducing the occurrence of noise and vibration.

[0047] The flow path effect of the working surface directly determines the pumping performance of the centrifugal pump. In the present invention, the first blade working surface and the second blade working surface are evenly provided with multiple twisted leaflets along the flow path direction, which also improves the pumping performance.

[0048] The inlet end of the second blade is axially protruding from the impeller upper cover plate. The above arrangement enables the second blade to also function as a guide vane, making the flow pattern at the blade inlet more stable and reliable.

[0049] The above-mentioned embodiments are illustrative of the present invention, not limiting thereof. It is understood that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A centrifugal pump with double helical blades, comprising a centrifugal impeller, wherein the centrifugal impeller comprises blades (1), an impeller upper cover plate (2), and an impeller lower cover plate (3), wherein the blades (1) are fixedly connected to the impeller upper cover plate (2) and the impeller lower cover plate (3); and characterized in that: The blade (1) consists of a first blade (8) and a second blade (9), wherein the first blade (8) includes a first blade working surface (4) and a first blade back surface (5), and the second blade (9) includes a second blade working surface (6) and a second blade back surface (7), and both the first blade (8) and the second blade (9) are spiral blades; wherein the contour line of the first blade working surface (4) is a part of an Archimedean spiral, and the contour line of the second blade back surface (7) is a part of a logarithmic spiral; the diameter of the suction port of the first blade (8) is D1, and the diameter of the suction port of the second blade (9) is D2, wherein D1<D2<1.5D1.

2. A centrifugal pump with double helical blades as claimed in claim 1, characterized in that: The contour line of the back surface (5) of the first blade includes a portion of a first equal-pitch helix (51) close to the inlet side and a portion of a first variable-pitch helix (52) away from the inlet side.

3. A centrifugal pump with double helical blades as claimed in claim 2, characterized in that: The angle between a point on the first equal-pitch helix (51) and the starting point of the contour line of the back side of the first blade (5) is θ1, wherein 0°≤θ1<30°; the angle between a point on the first variable-pitch helix (52) and the starting point of the contour line of the back side of the first blade (5) is θ2, wherein 30°≤θ2<300°.

4. A centrifugal pump with double helical blades as claimed in claim 1, characterized in that: The contour line of the second blade working surface (6) includes a portion of a second variable pitch helix (61) close to the inlet side and a portion of a second equal pitch helix (62) away from the inlet side.

5. A centrifugal pump with double helical blades as claimed in claim 4, characterized in that: The angle between a point on the second variable pitch helix (61) and the starting point of the contour line of the second blade working surface (6) is θ3, wherein 0°≤θ3<20°; the angle between a point on the second equal pitch helix (62) and the starting point of the contour line of the second blade working surface (6) is θ4, wherein 20°≤θ4<180°.

6. A centrifugal pump with double helical blades as claimed in claim 1, characterized in that: The inlet placement angle of the first blade (8) is β1, and the inlet placement angle of the second blade (9) is β2, wherein β1+β2=180°.

7. A centrifugal pump with double helical blades as claimed in claim 1, characterized in that: The outlet placement angle of the first blade (8) is β3, and the outlet placement angle of the second blade (9) is β4, wherein β3+β4=90°.

8. A centrifugal pump with double helical blades as claimed in claim 1, characterized in that: The leading edge and the trailing edge of the first blade (8) are both in an arc shape, and the leading edge and the trailing edge of the second blade (9) are both in a sharp tip shape.

9. A centrifugal pump with double helical blades as claimed in claim 1, characterized in that: The angle between the trailing edge of the first blade (8) and the trailing edge of the second blade (9) is θ, wherein 60°≤θ<120°.

10. A centrifugal pump with double helical blades as claimed in claim 1, characterized in that: The first blade working surface (4) and the second blade working surface (6) are evenly provided with a plurality of twisted leaflets (10) along the flow path direction.

11. A centrifugal pump with double helical blades as claimed in claim 1, characterized in that: The inlet end of the second blade (9) is arranged to protrude from the impeller upper cover plate (2) in the axial direction.

12. A roller granulator, comprising a humidifying spray system and a control system; characterized in that: The humidification spray system integrates a multimodal nozzle, which is connected to a centrifugal pump. The multimodal nozzle includes a high-pressure fan-shaped nozzle structure and a low-pressure conical spray structure. The control system adopts an AI algorithm module to dynamically optimize the spray pattern through a machine learning model. The centrifugal pump adopts a centrifugal pump with double helical blades as described in any one of claims 1 to 11.

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