A closed impeller slurry pump with controllable flexible blades

Abstract

The present invention discloses a closed impeller slurry pump with controllable flexible blades, comprising: a pump body, within which a pump shaft is mounted, a front cover plate disposed at the front end of the pump shaft, and a rear cover plate disposed at the rear end of the pump shaft; an impeller, a monolithic cast metal component, mounted on the pump shaft via a hub and restrained by shaft end nuts. The impeller cooperates with the front and rear cover plates to form a flow channel for the flow medium. The impeller is uniformly distributed with multiple blades, each comprising a cast iron front end, flexible blades at the rear end, and memory alloy strips. In the present invention, the front half of the blades is bonded to the hub to ensure rigidity, thereby facilitating work on the fluid entering the impeller. The rigidity of the rear half of the blades can be adjusted using a memory alloy. Impellers with different wrap angles and placement angles can be formed for different flow medium concentrations, thereby improving the operating efficiency of the slurry pump under different flow medium concentrations.

Description

Technical Field

[0001] The present invention relates to the technical field of slurry pumps, and in particular to a closed impeller slurry pump with controllable flexible blades. Background Art

[0002] Slurry pumps are an important type of industrial fluid conveying equipment, widely used in power plants, the building materials industry, the metallurgical industry, and the papermaking industry. In the papermaking industry, in particular, slurry pumps, as power units, account for over 90% of the total number of pumps in paper mills. The flow medium of a slurry pump is primarily a solid-liquid two-phase flow medium, and also contains a fiber suspension flow. The size of the solid particles ranges from nanoscale to macroscale, and the concentration ranges from extremely dilute to high concentrations, which will cause the flow medium to produce different rheological behaviors, among which non-Newtonian fluid mechanics is a very representative property. The so-called non-Newtonian fluid mechanics refers to the nonlinear relationship between the viscosity of the fluid and the change in the relative velocity of the flow motion. In a slurry pump, this manifests itself as different torques borne by the impeller when the slurry pump conveys slurries of different concentrations.

[0003] In addition, in order to ensure the flow performance of slurry, existing slurry pump products often adopt open or semi-open impellers. However, compared with closed impellers, the difference in blade form greatly limits the improvement of pump efficiency. Summary of the Invention

[0004] In order to solve the technical problems mentioned in the above background technology, the present invention designs a closed impeller slurry pump with controllable flexible blades, which can actively adjust its stiffness through temperature changes according to changes in flow rate and fluid medium properties to adapt to the fluid flow state, realize the function of efficient transportation, improve the working efficiency of the slurry pump, and reduce the starting load of the motor.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A closed impeller slurry pump with controllable flexible blades, comprising:

[0007] The pump body has a pump shaft installed therein, a front cover plate is arranged at the front end of the pump shaft, and a rear cover plate is arranged at the rear end of the pump shaft;

[0008] The impeller is an integral cast metal part, which is mounted on the pump shaft through the hub and limited by the shaft end nut. The impeller cooperates with the front cover plate and the rear cover plate to form a flow channel for the flow medium. The impeller has multiple blades evenly distributed on it, and the blades include cast iron, memory alloy strips and flexible blades;

[0009] The heating device is used to heat the pump shaft, transfer heat to the memory alloy strip through the pump shaft, and perform feedback adjustment according to the temperature of the memory alloy strip to control the blade stiffness.

[0010] In the present invention, the front half of the blade is combined with the hub to ensure rigidity so as to do work on the fluid entering the impeller. The rigidity of the back half of the blade can be adjusted by the memory alloy. For flow media of different concentrations, impellers with different wrap angles and placement angles are formed, thereby improving the operating efficiency of the slurry pump under flow media of different concentrations.

[0011] As a further description of the above technical solution:

[0012] The heating device comprises an infrared thermal probe, an electromagnetic coil and a controller, wherein the electromagnetic coil is wound on the pump shaft, and the infrared thermal probe and the controller are mounted on the rear cover plate.

[0013] As a further description of the above technical solution:

[0014] The infrared thermal sensor probe is used to detect the temperature of the impeller and transmit the temperature signal to the controller to adjust the heating temperature of the electromagnetic coil.

[0015] As a further description of the above technical solution:

[0016] The flexible blades are wrapped with several memory alloy strips, and the cast iron and flexible blades are bonded together with an adhesive. Considering the high manufacturing cost and fatigue failure risk of memory alloys, the flexible portion of the impeller is encased in hard rubber and bonded to the metal portion of the impeller. This significantly reduces the amount of memory alloy used while maintaining performance. Furthermore, if the memory alloy's properties change, the impeller's performance can be maintained by simply replacing the memory alloy.

[0017] As a further description of the above technical solution:

[0018] The impeller is provided with a plurality of balancing holes.

[0019] As a further description of the above technical solution:

[0020] The front cover is circumferentially provided with multiple circular holes, each housing a second magnet. A corresponding first magnet is positioned on the pump body, forming a magnetic attraction with the second magnet. The impeller front cover is magnetically secured, offering easy installation and a simple structure. The rear cover features a labyrinth seal, minimizing volumetric losses in the slurry pump.

[0021] As a further description of the above technical solution:

[0022] The impeller and rear cover are fitted with a labyrinth seal groove, and the rear cover is fitted with a mechanical seal where it meets the pump body and pump shaft, secured by a seal cap. The mechanical seal is equipped with a dedicated mechanical seal cap, simplifying the process of replacing the mechanical seal.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] 1. In the present invention, the front half of the blade is combined with the hub to ensure rigidity so as to do work on the fluid entering the impeller. The rigidity of the back half of the blade can be adjusted by the memory alloy. For different concentrations of the flow medium, impellers with different wrap angles and placement angles are formed, thereby improving the operating efficiency of the slurry pump under different concentrations of the flow medium.

[0025] 2. In the present invention, the pump shaft is heated by the principle of electromagnetic induction. The heat is transferred along the pump shaft to the impeller and finally to the nickel-titanium memory alloy bar to control its stiffness. The infrared thermal probe monitors the impeller temperature, thereby achieving precise control of the blade stiffness. The heating electromagnetic induction coil is equipped with an infrared thermal probe and a temperature control algorithm to achieve precise control of the temperature, ensuring that the blade stiffness meets the expected requirements.

[0026] 3. In the present invention, considering the high manufacturing cost and fatigue failure risk of memory alloy, the flexible part of the impeller adopts the method of wrapping the memory alloy with hard rubber, and bonding it to the metal part of the impeller. While ensuring the performance, the amount of memory alloy used is significantly reduced. At the same time, when the performance of the memory alloy changes, the impeller performance can be guaranteed by only replacing the memory alloy.

[0027] 4. In the present invention, the impeller is combined with the front and rear cover plates to form a flow channel that is approximately a closed impeller, thereby improving the hydraulic performance of the slurry pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic cross-sectional view of a closed impeller slurry pump with controllable flexible blades according to an embodiment of the present invention is shown;

[0029] Figure 2 A schematic diagram of the impeller structure of a closed impeller slurry pump with controllable flexible blades according to an embodiment of the present invention is shown;

[0030] Figure 3 A schematic diagram of the blade structure of a closed impeller slurry pump with controllable flexible blades according to an embodiment of the present invention is shown;

[0031] Figure 4 A schematic cross-sectional view of a rear cover plate of a closed impeller slurry pump with controllable flexible blades provided in accordance with an embodiment of the present invention is shown;

[0032] Figure 5 A schematic structural diagram of a front cover plate of a closed impeller slurry pump with controllable flexible blades according to an embodiment of the present invention is shown;

[0033] Figure 6A schematic diagram of the three-dimensional structure of a closed impeller slurry pump with controllable flexible blades provided according to an embodiment of the present invention is shown.

[0034] Legend:

[0035] 1. Pump body; 11. First magnet; 2. Impeller; 21. Cast iron; 22. Memory alloy; 23. Flexible blades; 24. Hub; 25. Balancing hole; 3. Pump shaft; 31. Shaft end nut; 4. Front cover; 41. Second magnet; 5. Rear cover; 51. Sealing cover; 52. Labyrinth seal groove; 6. Mechanical seal; 71. Infrared thermal sensor; 72. Electromagnetic coil; 73. Controller. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] Example 1

[0038] See also Figure 1-6 The present invention provides a technical solution: a closed impeller slurry pump with controllable flexible blades, comprising:

[0039] Pump body 1, such as Figure 1 As shown, a pump shaft 3 is installed therein. The pump shaft 3 is the main motor torque input component and is connected to the motor through a flat key. A front cover plate 4 is arranged at the front end of the pump shaft 3, and a rear cover plate 5 is arranged at the rear end of the pump shaft 3. A plurality of circular holes are arranged circumferentially on the front cover plate 4, and second magnets 41 are placed in the circular holes. A first magnet 11 that forms magnetic attraction with the second magnet 41 is provided at a corresponding position on the pump body 1 to ensure that the front cover plate 4 is axially fixed. The middle section of the front cover plate 4 has a boss structure for installation and cooperation between the front cover plate 4 and the pump body 1 to determine the radial position of the front cover plate 4. The rear cover plate 5 is connected to the pump body 1 by bolts and cooperates with the impeller 2 to ensure that the hydraulic performance of the flow channel is similar to that of a closed impeller. A labyrinth seal groove 52 is provided at the joint between the impeller 2 and the rear cover plate 5 to reduce leakage of the flow medium, reduce volume loss, and improve the overall efficiency of the pump equipment. A mechanical seal 6 is provided at the joint between the rear cover plate 5, the pump body 1 and the pump shaft 3, and is positioned by a sealing cover 51. The sealing cover 51 is installed on the rear cover plate 5 and is used to position the mechanical seal 6. During maintenance, the mechanical seal 6 can be replaced by removing the sealing cover 51 alone;

[0040] Impeller 2, such as Figure 2 and Figure 3As shown, it is an integral cast metal part, which is mounted on the pump shaft 3 through the hub 24 and limited by the shaft end nut 31. The impeller 2 cooperates with the front cover plate 4 and the rear cover plate 5 to form a flow channel for the flow medium. Its form is consistent with that of a closed impeller. There are seven blades evenly distributed on the impeller 2. The blades include a front cast iron 21, a nickel-titanium memory alloy strip 22 and a rear flexible blade 23. The cast iron 21 ensures the rigidity of the front half of the blade and provides energy for the fluid that has just entered the impeller 2. The flexible blade 23 is made of hard rubber, and the nickel-titanium memory alloy strip 22 has a certain degree of rigidity. Tonality, a number of memory alloy strips 22 are wrapped inside the flexible blades 23, and the cast iron 21 and the flexible blades 23 are bonded by an adhesive. The impeller 2 has multiple balancing holes 25 to reduce the axial force of the impeller 2. Specifically, the front half of the blade is combined with the hub 24 to ensure rigidity so as to do work on the fluid entering the impeller 2. The stiffness of the back half of the blade can be adjusted by the memory alloy strips 22. For different concentrations of the flow medium, the impeller 2 with different wrap angles and placement angles is formed to improve the operating efficiency of the slurry pump under different concentrations of the flow medium;

[0041] Heating devices, such as Figure 1 As shown, it is used to heat the pump shaft 3, transfer heat to the memory alloy strip 22 through the pump shaft 3, and perform feedback adjustment according to the temperature of the memory alloy strip 22 to control the blade stiffness. The heating device includes an infrared thermal probe 71, an electromagnetic coil 72 and a controller 73. The electromagnetic coil 72 is wound on the pump shaft 3, and the infrared thermal probe 71 and the controller 73 are installed on the rear cover 5. The controller 73 controls the electromagnetic coil 72 to adjust its temperature, and heats the pump shaft 3 through the electromagnetic induction principle. The heat is transferred along the pump shaft 3 to the impeller 2 and finally to the nickel-titanium memory alloy strip 22 to control its stiffness. The infrared thermal probe 71 monitors the temperature of the impeller 2, thereby realizing precise control of the blade stiffness. Specifically, the heating electromagnetic induction coil is equipped with an infrared sensor and a temperature control algorithm to realize precise control of the temperature to ensure that the blade stiffness meets the expected requirements. Among them, electromagnetic induction heating control and its feedback control are well-known technical means for those skilled in the art, so they will not be elaborated here.

[0042] During installation, the present invention first fixes the position of the pump body 1, installs the first magnet 11 into the groove of the pump body, and simultaneously installs the second magnet 41 into the circular hole of the front cover plate 4. Then, the installed front cover plate 4 is installed onto the pump body 1. When the second magnet 41 is firmly attracted, the installation of the front cover plate 4 is completed. Next, the flexible blades 23 are installed onto the memory alloy strips 22 to form a complete impeller 2. The impeller 2 is fixed to the pump shaft 3 and fixed with the shaft end nut 31. Next, the sealing cover 51 is bolted to the rear cover plate 5 to form a complete pump body rear cover plate 5. The mechanical seal 6 is then installed from the other end of the pump shaft 3 onto the pump shaft 3. The rear cover plate 5 is then installed and positioned by the impeller 2 and the mechanical seal 6. Finally, the rear cover plate 5, the pump shaft 3, and the impeller 2 are installed together onto the pump body 1 and connected with bolts to complete the installation.

[0043] Working principle: When in use, during the operation of the slurry pump, the motor drives the impeller 2 to rotate through the pump shaft 3, doing work on the conveying medium, thereby promoting the conveying of the slurry. The pump shaft 3 is heated by the principle of electromagnetic induction, and the heat is transferred along the pump shaft 3 to the impeller 2, and finally to the nickel-titanium memory alloy bar 22 to control its stiffness. The infrared thermal probe 71 monitors the temperature of the impeller 2, thereby achieving precise control of the blade stiffness. For different concentrations of the flowing medium, the impeller 2 is formed with different wrap angles and placement angles, thereby improving the operating efficiency of the slurry pump under different concentrations of the flowing medium;

[0044] When the slurry concentration is low, at the same speed and flow rate, the blades are subjected to less force, and the impeller 2 has a smaller wrap angle and a larger outlet placement angle. When the slurry concentration is high, the blades are subjected to greater force, and the impeller 2 has an increased wrap angle and a smaller outlet placement angle. By changing the shape of the blades, the performance range of the slurry pump is expanded, which can better adapt to the transportation of slurry media of different concentrations and improve the working efficiency of the pump.

[0045] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A closed impeller slurry pump with controllable flexible blades, characterized in that: include: A pump body (1) is provided with a pump shaft (3) therein, a front cover plate (4) is provided at the front end of the pump shaft (3), and a rear cover plate (5) is provided at the rear end of the pump shaft (3); The impeller (2) is an integrally cast metal part, which is mounted on the pump shaft (3) through the hub (24) and is limited by the shaft end nut (31). The impeller (2) cooperates with the front cover plate (4) and the rear cover plate (5) to form a flow channel for the flow medium. The impeller (2) has a plurality of blades evenly distributed on it, and the blades include cast iron (21), memory alloy strips (22) and flexible blades (23); When the motor of the pump body (1) is started, the cast iron (21) ensures the rigidity of the front half of the blade, providing energy for the fluid just entering the impeller (2). The flexible blade (23) is made of hard rubber, and the rigidity of the nickel-titanium memory alloy strip (22) has a certain degree of adjustability. The front half of the blade is combined with the hub (24) to ensure rigidity so as to perform work on the fluid entering the impeller (2). The rigidity of the rear half of the blade is adjusted by the memory alloy strip (22). For different concentrations of the flowing medium, the impeller (2) is formed with different wrap angles and placement angles, thereby improving the operating efficiency of the slurry pump under different concentrations of the flowing medium. A heating device is used for heating a pump shaft (3), transferring heat to a memory alloy strip (22) through the pump shaft (3), and performing feedback adjustment according to the temperature of the memory alloy strip (22) to control the blade stiffness.

2. A closed impeller slurry pump with controllable flexible blades according to claim 1, characterized in that: The heating device comprises an infrared thermal probe (71), an electromagnetic coil (72) and a controller (73), wherein the electromagnetic coil (72) is wound around the pump shaft (3), and the infrared thermal probe (71) and the controller (73) are mounted on the rear cover (5).

3. A closed impeller slurry pump with controllable flexible blades according to claim 2, characterized in that: The infrared thermal probe (71) is used to detect the temperature of the impeller (2) and transmit the temperature signal to the controller (73) to adjust the heating temperature of the electromagnetic coil (72).

4. A closed impeller slurry pump with controllable flexible blades according to claim 1, characterized in that: A plurality of memory alloy bars (22) are wrapped inside the flexible blade (23), and the cast iron (21) and the flexible blade (23) are bonded together by an adhesive.

5. A closed impeller slurry pump with controllable flexible blades according to claim 1, characterized in that: The impeller (2) is provided with a plurality of balancing holes (25).

6. A closed impeller slurry pump with controllable flexible blades according to claim 1, characterized in that: The front cover plate (4) is provided with a plurality of circular holes in the circumferential direction, and second magnets (41) are placed in the circular holes. A first magnet (11) is provided at a corresponding position on the pump body (1) to form a magnetic attraction with the second magnet (41).

7. A closed impeller slurry pump with controllable flexible blades according to claim 1, characterized in that: A labyrinth seal groove (52) is provided at the joint between the impeller (2) and the rear cover plate (5), and a mechanical seal (6) is provided at the joint between the rear cover plate (5), the pump body (1) and the pump shaft (3), and is positioned by a sealing cover (51).

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