Pump impeller and pump equipped with same

Abstract

To provide a pump capable of preventing or suppressing blockage of a plurality of blades formed in an impeller at an inner diameter part as much as possible.SOLUTION: A crushing pump 1 comprises a casing 20, and an impeller 4 arranged inside the casing 20 and rotated by a rotational shaft. The impeller 4 has a main plate 4a coaxially cantilevered on the tip side of a rotational shaft 3, and a plurality of blades 4b provided on a surface of the main plate 4a facing a suction side. The plurality of blades 4b are formed so that an inner diameter part of each blade 4b extends to a position where it is connected to a boss 4c provided at the center part of the main plate 4a.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a pump, and more particularly to an impeller suitable for use in a pump for transporting a transported fluid while crushing impurities contained in the transported fluid. [Background technology]

[0002] A fracturing pump is known as a pump suitable for crushing impurities contained in a transport fluid while transporting them. This type of fracturing pump is equipped with a casing having therein a crushing section that crushes the impurities in the transport fluid, and a centrifugal pump section that mixes the impurities crushed in the crushing section with the transport fluid to transport them as a solid-liquid mixture (see, for example, Patent Document 1).

[0003] This type of crushing pump is used, for example, in wastewater treatment facilities to process impurities such as hair, sanitary products, and disposable diapers. In order to prevent clogging of the piping equipment and blockage of the flow paths, the crushing pump crushes the impurities in the transported fluid and pumps them as a solid-liquid mixture. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP-A-08-135598 (FIG. 5) Summary of the Invention [Problem to be solved by the invention]

[0005] However, in this type of fracturing pump, clogging may occur not only in the piping equipment but also in the inner diameter part of the impeller. That is, as shown in Fig. 4, the impeller 104 in the casing 120 has multiple blades 104b on the front side of the main plate 104a, but in the conventional impeller 104, the inner diameter side end 104k of each blade 104b protrudes from a position separated from the boss 104c at the center of the main plate 104a, similar to the blade design adopted for the impeller in a normal centrifugal pump.

[0006] As a result, a space is created between the outer peripheral surface of the boss 104c and the inner diameter end 104k of each blade 104b into which impurities K can enter, resulting in a problem that the impurities K can become caught between the inner diameter end 104k of each blade 104b and the boss 104c, as in the crushing pump 100 shown in Figure 5.

[0007] In particular, in the case of crushing pumps used to treat sewage impurities, such as hair, sanitary products, and disposable diapers, it can be difficult to crush the impurities sufficiently in the crushing section, and blockages in the inner diameter of the impeller are more likely to occur.

[0008] Therefore, the present invention has been made with attention to such problems, and an object of the present invention is to provide a pump impeller that can prevent or suppress as much as possible blockage in the inner diameter portions of the multiple blades formed on the impeller, and a pump equipped with the same. [Means for solving the problem]

[0009] In order to solve the above problems, a pump impeller according to one embodiment of the present invention is used in a pump that transfers a transfer fluid from an axially forward suction port of a casing to a radially forward discharge port of the casing, and is an impeller disposed inside the casing and rotated by a rotating shaft, the impeller having a main plate coaxially supported on the tip side of the rotating shaft, and a plurality of blades provided on a surface of the main plate facing the suction port side, the plurality of blades being formed so that the inner diameter portion of each blade extends to a position connected to a boss provided in the center of the main plate.

[0010] In addition, in order to solve the above-mentioned problems, a pump according to one aspect of the present invention comprises a casing and an impeller disposed inside the casing and rotated by a rotating shaft, and transfers a transfer fluid from an axially forward suction port of the casing via the impeller to a radial discharge port of the casing, and is characterized in that the impeller is a pump impeller according to one aspect of the present invention.

[0011] According to a pump according to an aspect of the present invention, the pump impeller according to an aspect of the present invention is provided, and the inner diameter portion of each blade of the pump impeller according to an aspect of the present invention is extended to a position where it is connected to a boss provided at the center of the main plate, so that the centrifugal force of the rotating impeller can be used to forcibly splash impurities on the inner diameter portion of each blade toward the outer periphery of the main plate, thereby making it possible to prevent or suppress as much as possible clogging of the inner diameter portions of the multiple blades formed in the impeller. Effect of the Invention

[0012] As described above, according to the present invention, clogging of the inner diameter portion of each blade of the impeller can be prevented or suppressed as much as possible. [Brief description of the drawings]

[0013] [Figure 1] 1 is an illustration of one embodiment of a pump according to one aspect of the present invention, the cross section being taken along an axis. [Diagram 2] 2A is a cross-sectional view of a main portion of the impeller taken along the ZZ cross section in FIG. 1, and FIG. 2B is a projection view showing the relationship between the inner diameter portion of the impeller blade and a boss at the center of the main plate. [Diagram 3] 3A and 3B are diagrams showing modified examples of a plurality of impeller blades, and show views (a) and (b) corresponding to FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view of a main part of an impeller of a conventional pump, showing views (a) and (b) corresponding to FIG. 2. [Diagram 5] FIG. 1 is an explanatory diagram of an example of a conventional pump, showing a cross section taken along an axis line. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment is an example of application of a pump according to one aspect of the present invention to a crushing pump that crushes and transfers impurities contained in a transport fluid. Note that the drawings are schematic. Therefore, it should be noted that the relationship and ratio between thickness and planar dimensions are different from the actual ones, and the drawings include parts where the relationship and ratio of dimensions are different from each other. Furthermore, the embodiments described below are merely examples of devices and methods for embodying the technical ideas of the present invention, and the technical ideas of the present invention do not limit the materials, shapes, structures, arrangements, etc. of the components to the embodiments described below.

[0015] 1, the fracturing pump 1 of this embodiment includes a pump body 10 provided on the upper part of a base in an installation position. The pump body 10 includes a casing 20, a bearing mechanism 2 fixed to the rear part of the casing 20, and a rotating shaft 3 whose axis is supported horizontally by the bearing mechanism 2.

[0016] The casing 20 is produced by casting, and in the installed position, an upper portion of the casing 20 is provided with a discharge port 21 that opens upward. A drive motor is connected to the rear end of the rotating shaft 3 via a coupling (not shown). In the pump body 10 of this embodiment, the impeller 4 is fixed in a cantilevered state to the tip side of the rotating shaft 3 so as to be located in a defined space inside the casing 20.

[0017] In the fracturing pump 1 of this embodiment, in order to increase the pump head of the volute pump, the flow path of the casing 20 is formed so as to gradually expand in diameter in an involute curve toward the discharge port 21 located radially outside the impeller 4.

[0018] In addition, since the crushing pump 1 of this embodiment is a pump for treating human waste impurities such as hair, sanitary products, paper diapers, and leftover food, the pump bore (discharge diameter) is preferably in the range of Φ65 mm to Φ150 mm. If the pump bore is a small bore diameter of less than Φ65 mm, the flow path in the casing 20 becomes narrow, making it difficult to smoothly pass the human waste impurities as described above.

[0019] In the crushing pump 1 of this embodiment, as shown in the figure, the crushing section casing 5 is fixed by bolts to the upstream side of the suction passage of the casing 20 coaxially with the axis of the rotating shaft 3. Furthermore, on the upstream side of the suction passage of the casing 20, the suction casing 30 having a suction port 31 formed in the center is fixed by bolts to the front side of the crushing section casing 5 coaxially with the axis of the rotating shaft 3.

[0020] In the space defined inside the crushing section casing 5, a crushing impeller 6 is fixed to the tip of the rotating shaft 3, and this crushing impeller 6 rotates integrally with the impeller 4 on the suction passage side of the casing 20. In addition, a disk-shaped fixed blade 7 is fixed to the rear of the inner peripheral surface of the crushing section casing 5 in the axial direction so as to form a small gap between the rear surface of the crushing impeller 6 and the blade 7.

[0021] Furthermore, in the crushing pump 1 of this embodiment, a circular shroud ring 8 is provided between the inner surface of the crushing section casing 5 and the outer surface of the crushing impeller 6 so as to form a small radial gap between the crushing impeller 6.

[0022] In the installed position, the crushing blade 9 is provided at the upper part of the suction casing 30 at an attachment part penetrating the upper part of the suction casing 30 from diagonally above. The crushing blade 9 is arranged so that its tip faces the front face of the crushing impeller 6 with a small gap in the axial direction.

[0023] As a result, the crushing impeller 6, the crushing blades 9 at the rear of the suction casing 30, and the shroud ring 8 and fixed blades 7 provided on the crushing section casing 5 constitute a crushing section that crushes impurities in the transported fluid.

[0024] In the fracturing pump 1 of this embodiment, the impeller 4 has a disk-shaped main plate 4a and a plurality of blades 4b provided on the surface of the main plate 4a facing the suction side, and the front edges of the plurality of blades 4b are attached to face the inner wall surface of the casing 20. This impeller 4 rotates by the rotating shaft 3 inside the casing 20 to constitute a volute pump section that transfers the transfer fluid.

[0025] More specifically, in the fracturing pump 1 of this embodiment, as shown in Fig. 2, the multiple blades 4b of the impeller 4 are equally arranged in three positions in the circumferential direction on the front surface of the main plate 4a. Each blade 4b is formed to spread radially in the circumferential direction from the boss 4c at the center of the main plate 4a and to be curved in a spiral shape, so that the distance between adjacent blades 4b in the opposing direction increases as they move radially outward. The space between adjacent blades 4b forms a flow path for the transported fluid.

[0026] Here, in this type of fracturing pump, clogging may occur even in the inner diameter part of the impeller, but in the fracturing pump 1 of this embodiment, the inner diameter part of each blade 4b of the impeller 4 is extended to the boss 4c at the center of the main plate 4a, and the end part 4k on the inner diameter side is integrally formed with the outer circumferential surface of the boss 4c, so that the impurities around the boss 4c can be forcibly thrown up to the outer circumferential side of the main plate 4a by using centrifugal force. In particular, in this embodiment, the front edge part of each blade 4b is formed to extend to the same height to the position connected to the boss 4c.

[0027] In this embodiment, the shape of each blade 4b is widest at the end 4k on the inner diameter side connected to the boss 4c, and the width gradually narrows from the base end of the end 4k to the middle part toward the outer periphery, and continues as a smooth arc of almost constant width from the middle part of each blade 4b to the tip on the outer periphery. In this embodiment, each blade 4b has basically the same curved shape, width dimension, and thickness dimension, and therefore has the same performance.

[0028] Next, the operation and effects of the crushing pump 1 of this embodiment will be described. In the crushing pump 1 of this embodiment, when a drive motor (not shown in FIG. 1) is driven, the rotational force of the drive motor is transmitted to the rotating shaft 3 supported by the bearing mechanism 2 via a coupling, and the impeller 4 and the crushing impeller 6 rotate integrally with the rotation of the rotating shaft 3.

[0029] As a result, according to the crushing pump 1 of this embodiment, impurities are sucked in together with the transport fluid from the suction port 31 of the suction casing 30, and inside the crushing section casing 5, the impurities contained in the transport fluid can be crushed by the cooperation of the crushing impeller 6, shroud ring 8, crushing blade 9, and fixed blade 7.

[0030] Furthermore, the crushed impurities can be pumped as a solid-liquid mixture mixed with the transport fluid by the rear impeller 4 toward the discharge port 21 at the top of the casing 20. Note that the mechanism of action of the crushing in the crushing section and the mechanism of action of the pumping in the centrifugal pump section are the same as those of known crushing pumps, so detailed explanations will be omitted.

[0031] As described above, in this type of crushing pump, although the impurities are crushed in the crushing section, depending on the nature of the impurities, clogging may occur in the inner diameter of the multiple blades formed on the impeller. In particular, in the case of a crushing pump for treating human waste impurities, since impurities such as hair, sanitary products, and paper diapers are treated, it may be difficult to crush sufficiently in the crushing section, and there is a problem that clogging is more likely to occur in the inner diameter of each blade.

[0032] In contrast, according to the fracturing pump 1 of this embodiment, as shown in Fig. 2, the impeller 4 extends the inner diameter side end 4k of each blade 4b to the boss 4c, so that the impurities in the inner diameter part of each blade 4b can be forcibly thrown up toward the outer periphery side of the main plate 4a by using the centrifugal force of the rotating impeller 4. Therefore, clogging in the inner diameter part of the multiple blades 4b formed on the impeller 4 can be prevented or suppressed as much as possible.

[0033] In other words, in a typical centrifugal pump as shown in Figures 4 and 5, the flow path at the portion of the multiple blades 104b formed on the impeller 104 is narrowed to reduce the flow rate and convert it into pressure, thereby improving the pump efficiency.

[0034] However, in the blade design used in typical centrifugal pumps, as shown in Figures 4 and 5, the inner diameter end portion 104k of each blade 104b is formed away from the outer peripheral surface of the boss 104c on the inner diameter side, and impurities K in the transported fluid become caught on the inner diameter portion of the multiple blades 104b formed on the impeller 104 around the boss 104c.

[0035] In particular, when there are many blades 104b (for example, four or more), the blades 104b are crowded near the boss 104c, hindering smooth flow. Also, when there are many blades 104b, it is difficult to extend the blade shape to match the smooth flow. For this reason, the blade design used in normal centrifugal pumps is formed so that the end 104k of the blade 104b on the center side is located away from the boss 104c.

[0036] In contrast, in the impeller 4 of this embodiment, emphasis is placed on the passage of impurities rather than on improving the pump efficiency of the fracturing pump 1, and for pump efficiency, a blade design is adopted that has a head performance that allows the transfer of the transfer fluid to the next process. That is, in order to prevent or suppress the entrapment of impurities, as shown in FIG. 2, as in the fracturing pump 1 of this embodiment, it is an effective measure to extend the inner diameter part of each blade 4b to the boss 4c, integrate the inner diameter side end k with the boss 4c, and use centrifugal force to forcibly jump up the impurities in the inner diameter part of each blade 4b to the outer periphery side of the main plate 4a. In this way, it can be said that there is a trade-off between the pump efficiency and the passage performance of impurities due to the impeller blade design.

[0037] The pump impeller and pump according to the present invention are not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. For example, in the above embodiment, an example in which three blades 4b are provided on the front surface of the main plate 4a is shown as an example of the plurality of blades 4b, but the present invention is not limited to this.

[0038] For example, as shown in a modified example in Fig. 3, a configuration can be adopted in which two blades 4b are provided on the front surface of the main plate 4a. In the example in the figure, the inner diameter portions of the two blades 4b are also extended to the boss 4c, and the end portions k on the inner diameter side are integrated with the boss 4c. Therefore, as in the above embodiment, it is possible to forcibly splash up impurities on the inner diameter portions of the blades 4b to the outer periphery side of the main plate 4a by using centrifugal force.

[0039] However, the greater the number of blades, the smaller the particle size passing through the flow passage between adjacent blades 4b. This is disadvantageous in terms of preventing or suppressing clogging in the inner diameter portion of the impeller. Therefore, in order to prevent or suppress clogging in the inner diameter portion of the impeller as much as possible, it is desirable to limit the number of blades 4b to three or less, as shown in Figure 2 or Figure 3.

[0040] In addition, for example, in the above embodiment, an example of application to a crushing pump 1 for treating sewage impurities was shown as an example of a pump that can prevent or suppress clogging at the inner diameter portion of the impeller 4 as much as possible, but the pump impeller and pump of the present invention are not limited to this and can be applied to various pumps.

[0041] For example, in the above embodiment, an example of application to a crushing pump with a built-in crushing impeller was shown, but the present invention can be applied to an impeller of a pump that does not have a crushing impeller. Also, the present invention is not limited to a pump with a built-in crushing mechanism, and as long as it is possible to crush impurities in the transported fluid on the suction side of the casing, the crushing mechanism may be attached externally to the pump, for example. [Explanation of symbols]

[0042] 1. Fracturing pump (pump) 2 Bearing mechanism 3 Rotation Axis 4 Impeller 4a Main plate 4b Feather 4c Boss 5 Crushing section casing 6 Crushing impeller 7 Fixed blade 8 Shroud Ring 9 Crushing blade 10 Pump body 20 Casing 21 Discharge port 30 Suction casing 31 Intake port 104 Impeller 104a Main plate 104b Feather 104c Boss K Contaminants

Claims

1. An impeller used in a pump that transfers a transfer fluid from a suction port at a front side of a casing in an axial direction to a discharge port in a radial direction of the casing, the impeller being disposed inside the casing and rotated by a rotating shaft, A main plate is coaxially supported on the tip side of the rotating shaft, and a plurality of blades are provided on a surface of the main plate facing the suction port side, Only the plurality of blades are provided on a surface of the main plate facing the suction port side, The plurality of blades are formed such that an inner diameter portion of each blade extends to a position connected to a boss provided at the center of the main plate, The blade has a shape in which the width of an end portion on the inner diameter side connected to the boss is the widest, the width of the end portion narrows from the base end portion of the end portion toward the outer periphery, and the width of the blade is continuous from the tip portion on the outer periphery side to the base end portion by a smooth curve, 13. A pump impeller, comprising: a boss having a boss section and a boss section extending in a direction parallel to the axis of rotation of the impeller;

2. 2. The pump impeller according to claim 1, wherein leading edges of the plurality of blades are formed to extend at the same height to a position connected to the boss.

3. 3. The pump impeller according to claim 1, wherein the number of the blades is three or less.

4. A pump comprising: a casing; and an impeller disposed inside the casing and rotated by a rotary shaft, the pump transferring a transfer fluid from a suction port at a front side in an axial direction of the casing to a discharge port in a radial direction of the casing via the impeller, A pump comprising the pump impeller according to any one of claims 1 to 3 as the impeller.

5. 5. The pump according to claim 4, further comprising a crushing mechanism for crushing impurities in the transported fluid on the suction side of the casing.

6. 6. The pump according to claim 5, wherein the crushing mechanism is a crushing impeller attached to the tip of the rotary shaft and mounted on the suction side of the casing so as to be capable of crushing impurities in the transported fluid.

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