JP2007092565A - Centrifugal pump, mixed flow pump, axial flow pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a centrifugal pump, a mixed flow pump, an axial flow pump, eliminating a swirl component (a circumferential velocity) of a back flow generated around an impeller inlet part causing a pump excessive vibrations in a partial flow operation and to suppress the pump excessive vibrations in a partial flow area. <P>SOLUTION: In the centrifugal pump having a pump casing 10 and an impeller 13, a liner ring 17 is interposed between a pump casing 10 and an impeller inlet 13a, a plurality of fins 18 are disposed in a circumferential direction of a liquid flow inlet side of the liner ring 17 to prevent a backflow swirl component of a liquid flow in a center direction of the inside of the impeller inlet 13a or a direction inclined by a predetermined angle with respect to the center direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a centrifugal pump, a mixed flow pump, and an axial flow pump, and more particularly to a centrifugal pump, a mixed flow pump, and an axial flow pump that can suppress excessive vibration in a partial flow rate region and improve pump performance. is there.

  In the centrifugal pump, the mixed flow pump, and the axial flow pump, of the liquid that has flowed into the impeller inlet in the partial flow operation, the liquid that could not flow out of the impeller outlet flows back from the impeller inlet while being rotated by the impeller. The reverse flow of the liquid having the swirl component becomes an excessive vibration source in the partial flow rate region of the pump.

  Further, in both suction centrifugal pumps that are centrifugal pumps, the inflowed liquid flows into the impeller in a state of having a certain degree of swirling (pre-swirling). However, the flow at the impeller inflow section is not uniform in the circumferential direction, so the inlet blade angle of the impeller cannot be optimal when viewed locally, although it matches the liquid inflow flow on average, which improves pump performance. It is a barrier.

  FIG.1 and FIG.2 is a figure which shows the structural example of the double suction vortex pump which is an example of a centrifugal pump. 1 is a front sectional view (BB cross section in FIG. 2), and FIG. 2 is a side view (viewed along arrow A in FIG. 1). As shown in the figure, the pump casing 10 has a front section in which a discharge casing portion 12 is disposed at the center of the suction casing portion 11, and the suction port 11 a of the suction casing portion 11 and the discharge port 12 a of the discharge casing portion 12 are opposite to each other. It has become. An impeller 13 fixed to the main shaft 14 is disposed at the center of the pump casing 10. Both ends of the main shaft 14 are rotatably supported by bearings 15, 15, and a driving device (not shown) such as an electric motor is connected to one end of the main shaft 14. In FIG. 1, 16 and 16 are shaft seals, and 17 and 17 are liner rings.

  When the impeller 13 is rotated together with the main shaft 14 by a driving device (not shown) in the two suction centrifugal pumps having the above-described configuration, the liquid sucked from the suction port 11a of the suction casing portion 11 by the rotation of the impeller 13 is moved through the inside of the suction casing portion 11 with an arrow. C, flows from the impeller inlet 13a into the impeller 13, flows in the discharge casing portion 12 as indicated by arrow E, and the discharge port 12a of the discharge casing portion 12 disposed on the side opposite to the suction port 11a. Is exhaled from.

  In the flow of the liquid during the operation of the dual suction centrifugal pump having the above-described configuration, the liquid that could not flow out from the outlet 13b of the impeller 13 in the partial flow operation becomes a reverse flow as indicated by an arrow D at the impeller inlet 13a. This reverse flow has a swirl component (circumferential speed), which increases the vibration speed in the partial flow rate region C as shown by the curve B in FIG. 3, and causes excessive pump vibration as described above. . In addition, the cause of such pump vibration also has other centrifugal pumps, mixed flow pumps, and axial flow pumps.

  Further, in the above two centrifugal pumps, the liquid sucked from the suction port 11a of the suction casing portion 11 flows in a state where the swirl is performed to some extent as described above. However, as shown in FIG. The liquid flow is not uniform in the circumferential direction and adversely affects pump performance. It should be noted that such a non-uniform flow of liquid in the circumferential direction of the impeller inlet portion that adversely affects the pump performance has not only both suction centrifugal pumps but also other centrifugal pumps.

  The present invention has been made in view of the above points, and eliminates the swirl component (circumferential speed) of the reverse flow generated at the impeller inlet that causes excessive pump vibration in partial flow operation, and excessive vibration in the partial flow region. An object of the present invention is to provide a centrifugal pump, a mixed flow pump, and an axial flow pump that can suppress the above.

  It is another object of the present invention to provide a centrifugal pump that improves the pump performance by removing a non-uniform flow of liquid in the circumferential direction of the impeller inlet portion that adversely affects the pump performance.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a centrifugal pump comprising a pump casing and an impeller, wherein a liner ring is interposed between the pump casing and the impeller inlet. A plurality of fins for preventing a counter-current swirl component of the liquid flow in the central direction of the impeller inlet or in a direction inclined by a predetermined angle with respect to the central direction is provided in the end circumferential direction.

  According to a second aspect of the present invention, in the centrifugal pump according to the first aspect, a reinforcing ring for reinforcing the fins is provided at an inner end of the plurality of fins.

  The invention according to claim 3 is a centrifugal pump comprising a pump casing and an impeller, wherein a liner ring is interposed between the pump casing and the impeller inlet, and the liquid inflow side end portion of the liner ring is the impeller inlet. A jaw portion having an inclined surface that protrudes from the liquid inflow side end portion to a liquid inflow side at a predetermined angle and is inclined toward the impeller inlet side, and the impeller inlet in the circumferential direction of the liquid inflow side end portion of the jaw portion A plurality of fins for preventing a counter-current swirling component of the liquid flow are provided in the central direction or a direction inclined by a predetermined angle with respect to the central direction.

  According to a fourth aspect of the present invention, in the centrifugal pump according to the third aspect, a reinforcing ring for reinforcing the fins is provided at the inner ends of the plurality of fins.

  The invention according to claim 5 is a mixed flow pump or an axial flow pump that includes a pump casing and an impeller, and a liner ring is interposed between the pump casing and the impeller, and the impeller liquid inflow side end. A plurality of fins for preventing a counter-current swirling component of the liquid flow in the circumferential direction of the impeller inlet in the circumferential direction or a direction inclined by a predetermined angle with respect to the central direction are provided on the inner circumferential surface of the liner ring or the pump casing. It is characterized by that.

  According to a sixth aspect of the present invention, in the mixed flow pump or the axial flow pump according to the fifth aspect, a reinforcing ring for reinforcing the fins is provided at an inner end of the plurality of fins.

  The invention according to claim 7 is a centrifugal pump comprising a pump casing and an impeller, wherein a liner ring is interposed between the pump casing and the impeller inlet. A plurality of rectifying plates are provided on the outer peripheral side of the impeller inlet for rectifying the liquid flow flowing into the impeller inlet in a direction inclined by a predetermined angle with respect to the radial direction.

  According to an eighth aspect of the present invention, in the centrifugal pump according to the seventh aspect, a reinforcing ring that reinforces the rectifying plates is provided at the liquid inflow side ends of the plurality of rectifying plates.

  The invention according to claim 9 is a centrifugal pump comprising a pump casing and an impeller, wherein a liner ring is interposed between the pump casing and the impeller inlet. Provided with a plurality of countercurrent swirl component preventing / rectifying plates that prevent the countercurrent swirl component of the liquid flow in a direction inclined by a predetermined angle with respect to the radial direction on the inner peripheral side and outer peripheral side of the impeller inlet and rectify the liquid flow. Features.

  According to a tenth aspect of the present invention, in the centrifugal pump according to the ninth aspect, a reinforcing ring for reinforcing the countercurrent swirl component preventing / rectifying plate is provided at an inner end of the plurality of countercurrent swirling component preventing / rectifying plates. It is characterized by.

  According to the first aspect of the present invention, a plurality of reverse flow swirling components of the liquid flow are prevented in the circumferential direction of the liquid inlet side of the liner ring in the circumferential direction of the impeller inlet or in a direction inclined by a predetermined angle with respect to the central direction. Since the fins are provided, it is possible to provide a centrifugal pump that can prevent the swirl component of the backflow generated at the impeller inlet and prevent a large vibration speed (excessive vibration) in the partial flow rate region of the pump.

  According to the second aspect of the present invention, since the reinforcing ring for reinforcing the fins is provided at the inner ends of the plurality of fins, the fins are reinforced, and there is an effect that the large vibration speed can be suppressed in the partial flow rate region of the pump. Further improvement.

  According to the third aspect of the present invention, the counter-current swirl component of the liquid flow in the circumferential direction of the liquid inflow side end portion of the jaw portion of the liner ring in the central direction of the impeller inlet or in a direction inclined by a predetermined angle with respect to the central direction. Since the plurality of fins to be prevented are provided, it is possible to provide a centrifugal pump that prevents the swirling component of the backflow generated at the impeller inlet and prevents a large vibration speed in the partial flow rate region of the pump.

  According to the fourth aspect of the present invention, since the reinforcing ring for reinforcing the fins is provided at the inner ends of the plurality of fins, the fins are reinforced, and there is an effect that the large vibration speed can be suppressed in the partial flow rate region of the pump. Further improvement.

  According to the fifth aspect of the present invention, the inner ring peripheral surface or the pump casing inner peripheral surface in the vicinity of the impeller liquid inflow side end portion in the circumferential direction impeller inlet central direction or a direction inclined by a predetermined angle with respect to the central direction. Since a plurality of fins for preventing the reverse flow swirl component of the liquid flow are provided, the swirl component of the reverse flow generated at the inlet of the impeller is prevented, and a mixed flow pump that can suppress a large vibration speed in the partial flow rate region of the pump Alternatively, an axial flow pump can be provided.

  According to the sixth aspect of the present invention, since the reinforcing ring for reinforcing the fins is provided at the inner ends of the plurality of fins, the fins are reinforced, and there is an effect that the large vibration speed can be suppressed in the partial flow rate region of the pump. Further improvement.

  According to the seventh aspect of the present invention, a plurality of rectifying liquid flows flowing into the impeller inlet in a direction inclined at a predetermined angle with respect to the outer peripheral side of the impeller inlet in the circumferential direction of the liquid inlet side of the liner ring with respect to the radial direction. Since the current plate is provided, the liquid flow flowing into the impeller is made uniform, and a centrifugal pump with improved pump performance can be provided.

  According to the eighth aspect of the present invention, since the reinforcing ring that reinforces the current plate is provided at the liquid inflow side end of the plurality of current plates, the pump performance is further improved.

  According to the ninth aspect of the present invention, the reverse flow swirl component of the liquid flow is inclined in a direction inclined at a predetermined angle with respect to the radial direction on the inner peripheral side and the outer peripheral side of the impeller inlet in the circumferential direction of the liquid inlet side of the liner ring. Since a plurality of backflow swirl component preventing / rectifying plates that prevent and rectify the liquid flow are provided, it is possible to provide a centrifugal pump that can suppress a large vibration speed and improve pump performance in a partial flow rate region of the pump.

  According to the invention described in claim 10, since the reinforcing ring for reinforcing the backflow swirl component preventing / rectifying plate is provided at the inner end of the backflow swirling component preventing / rectifying plate, a large vibration speed is generated in the partial flow rate region of the pump. The suppressing action and the pump performance are further improved.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a diagram showing a front cross-sectional configuration (corresponding to the BB cross section of FIG. 2) of a main part of a double suction centrifugal pump which is an example of a centrifugal pump according to the present invention, and FIG. 5 shows a configuration of a liner ring unit. FIG. In FIG. 4, the parts denoted by the same reference numerals as those in FIGS. 1 and 2 indicate the same or corresponding parts. The same applies to other drawings. In the both suction centrifugal pumps, a discharge casing portion 12 is arranged in the center of the suction casing portion 11 in the front section of the pump casing 10, and a suction port (not shown) of the suction casing portion 11 and a discharge port of the discharge casing portion 12 are arranged. The outlets (not shown) are opposite to each other, and the impeller 13 fixed to the main shaft 14 is disposed at the center of the pump casing 10 because the two suction centrifugal pumps shown in FIGS. Are the same.

  The difference between this suction pump and the suction pump shown in FIGS. 1 and 2 is that, as shown in FIGS. 4 and 5, the circumferential edges of the liquid inflow side ends of the liner rings 17 and 17 are equally spaced. And the point which has provided the several fin 18 which goes to the center O of the impeller inlet 13a. Thus, by providing a plurality of fins at equal intervals in the circumferential direction on the liquid inflow side end portions of the liner rings 17, 17, the swirl component of the reverse flow generated near the impeller inlet 13 a is blocked by the plurality of fins 18. Therefore, the large vibration speed (excessive vibration) generated in the partial flow rate region of the pump can be suppressed.

FIG. 4 is a diagram showing test results of the pump flow rate (m ³ / min) and the vibration speed peak (mm / s) in FIG. 3, and a curve A shows a plurality of fins 18 in the circumferential direction of the liner rings 17 and 17 on both suction spiral pumps. As for the test results of the two suction centrifugal pumps according to the present invention, the curve B shows a conventional example in which the liner rings 17 and 17 are not provided with a plurality of fins. As shown in the figure, in the double suction centrifugal pump according to the present invention in which a plurality of fins 18 are provided at equal intervals in the circumferential direction of the liquid inflow side ends of the liner rings 17, 17, the vibration speed in the partial flow region C is the conventional example. It turns out that it is small compared.

  Further, in the above example, each fin 18 is arranged toward the center O of the impeller inlet 13a, but the direction in which the fin 18 faces is in the direction (radial direction) toward the center O of the impeller inlet 13a as shown in FIG. On the other hand, excessive vibration generated in the partial flow rate region of the pump can be suppressed even if the liquid flow flowing into the impeller 13 is made uniform in a direction inclined by a predetermined angle. In the above example, the fins 18 are provided at equal intervals in the circumferential direction of the liquid inflow side end portions of the liner rings 17, 17. The swirl component of the reverse flow generated in the vicinity of the impeller inlet 13a can be prevented, and the large vibration speed (excessive vibration) generated in the partial flow rate region of the pump can be suppressed.

  FIG. 7 is a diagram showing a front cross-sectional configuration of the main part of both suction centrifugal pumps according to the present invention, and FIGS. 8 and 9 are diagrams showing the configuration of the liner ring portion. As shown in the figure, the both suction centrifugal pumps are provided at equal intervals in the circumferential direction of the liquid inflow end of the liner ring 17 and toward the center of the impeller inlet 13a as shown in FIGS. A reinforcing ring 19 for reinforcing the fins 18 is provided at the inner ends of the plurality of fins 18. Further, as shown in FIGS. 7 and 9, a plurality of lines provided at equal intervals in the circumferential direction of the liquid inflow side end of the liner ring 17 and in a direction inclined at a predetermined angle with respect to the center O direction of the impeller inlet 13a. A reinforcing ring 19 for reinforcing the fin is provided at the inner end of the fin 18.

  Thus, by providing the reinforcing ring 19 at the inner ends of the plurality of fins 18, the fins 18 are reinforced, and vibrations or the like are not generated in the fins 18 due to the liquid flow flowing into the impeller 13. It is possible to further improve the action of suppressing the excessive vibration that occurs. In this case as well, the fins 18 do not necessarily have to be provided at equal intervals in the circumferential direction of the liquid inflow side end portions of the liner rings 17 and 17, and even if they are unequal intervals, the swirl component of the reverse flow generated near the impeller inlet 13 a is somewhat inhibited. The large vibration speed (excessive vibration) generated in the partial flow rate region of the pump can be suppressed.

  FIG. 10A is a diagram showing a front cross-sectional configuration of the main part of the double suction centrifugal pump according to the present invention, and FIG. 10B is an enlarged view of a portion B of FIG. This dual suction centrifugal pump is different from the dual suction centrifugal pump shown in FIG. 4 in that the liquid inflow side end of the liner ring 17 is more than the liquid inflow side end of the impeller inlet 13a as shown in FIG. A jaw portion (protruding portion) 17a having an inclined surface protruding to the liquid inflow side by a predetermined angle and inclined to the impeller inlet side is formed. A plurality of backflow swirling components of the liquid flow are prevented at the liquid inflow side end of the jaw portion 17a at equal intervals in the circumferential direction and toward the impeller inlet central direction or a direction inclined at a predetermined angle with respect to the central direction. Fins 18 are provided (see FIGS. 5 and 6).

  The liner ring 17 having the jaw portion 17a as described above is directed to the liquid inflow side end portion of the jaw portion 17a at equal intervals in the circumferential direction toward the impeller inlet central direction or a direction inclined by a predetermined angle with respect to the central direction. By providing the plurality of fins 18 for preventing the reverse flow swirl component of the liquid flow, excessive vibrations generated in the partial flow rate region of the pump can be suppressed as in the case of the double suction centrifugal pump shown in FIG.

  FIG. 11 is a diagram showing a front cross-sectional configuration of the main part of the double suction centrifugal pump according to the present invention. The difference between the double suction centrifugal pump and the double suction centrifugal pump shown in FIG. A reinforcing ring 19 for reinforcing the fin 18 is provided at the end (see FIGS. 8 and 9). Thus, by providing the reinforcing ring 19 at the inner ends of the plurality of fins 18, the fins 18 are reinforced, and vibrations or the like are not generated in the fins 18 due to the liquid flow flowing into the impeller 13. It is possible to further improve the action of suppressing the excessive vibration that occurs. 10 and 11, the fins 18 do not necessarily have to be provided at equal intervals in the circumferential direction of the liquid inflow end portions of the liner rings 17 and 17, and the impeller inlet 13a is not evenly spaced. It is possible to prevent the swirl component of the reverse flow generated in the vicinity of to some extent, and to suppress a large vibration speed (excessive vibration) generated in the partial flow rate region of the pump.

  FIG. 12 is a view showing a side configuration of the mixed flow pump according to the present invention. As shown in the figure, this mixed flow pump includes a pump casing including a suction bell 20 and a discharge bowl 21, and a discharge pipe 22 is connected to a discharge port of the discharge bowl 21. Reference numeral 23 denotes a pump impeller, which is fixed to the front end of a main shaft 24 via a hub 25, and the pump impeller 23 has a rear end of the suction bell 20 that constitutes a pump casing. Located close to the inner surface. The liner ring 17 is attached to the inner peripheral surface of the suction bell 20 so as to face the tip of the pump impeller 23.

  In the mixed flow pump configured as described above, when the pump impeller 23 is rotated by the rotation of the main shaft 24, the liquid sucked from the suction port of the suction bell 20 passes through the discharge bowl 21 and is discharged to the discharge pipe 22. Even in such a mixed flow pump, a portion of the liquid flowing into the inlet of the pump impeller 23 in the partial flow operation that cannot be discharged from the outlet of the pump impeller 23 is rotated by the pump impeller 23 while being pumped. It flows backward from the entrance of the car 23. The reverse flow having this swirl component becomes an excessive vibration source in the partial flow rate region of the pump as described above.

  Therefore, here, as shown in FIGS. 12 and 13, the inlet center of the pump impeller 23 (center of the suction bell 20) is equally spaced in the circumferential direction on the inner peripheral surface near the liquid inflow side end of the liner ring 17. A plurality of fins 18 are provided to prevent a reverse flow swirl component of the liquid flow (see FIG. 5). FIG. 13 is an enlarged view of a portion A in FIG. Thus, by providing a plurality of fins 18 at equal intervals in the circumferential direction on the inner peripheral surface of the liquid inflow side end portion of the liner ring 17, the reverse flow swirl component of the liquid flow is blocked by the plurality of fins 18. Excessive vibration generated in the partial flow rate region of the pump can be suppressed.

  The plurality of fins 18 may be provided in a direction inclined by a predetermined angle with respect to the direction of the inlet center of the pump impeller 23 (center of the suction bell 20) as shown in FIG. As a result, the flow of the liquid flowing into the impeller 23 is made uniform, and excessive vibration generated in the partial flow rate region of the pump can be suppressed.

  As shown in FIGS. 8 and 9, the fins 18 are reinforced by providing the inner ends of the plurality of fins 18, and vibrations and the like are generated in the fins 18 due to the liquid flow flowing into the pump impeller 23. Without this, it is possible to further improve the suppression action of excessive vibration generated in the partial flow rate region of the pump. Note that the fins 18 do not necessarily have to be provided at equal intervals in the circumferential direction of the liquid inflow end portions of the liner rings 17 and 17, and even if they are unequal intervals, the reverse swirl component generated in the vicinity of the pump impeller inlet 23 a is prevented to some extent. The large vibration speed (excessive vibration) generated in the partial flow rate region of the pump can be suppressed.

  In the above example, a plurality of fins 18 are provided at equal intervals in the circumferential direction of the liquid inflow side end of the liner ring 17, but when there is no liner ring 17 as shown in FIG. A plurality of fins 18 may be provided on the inner peripheral surface of the suction bell (a part of the pump casing) 20 in the vicinity of the liquid inflow side end portion directly at equal intervals in the circumferential direction. Thus, even when the plurality of fins 18 are directly provided on the inner peripheral surface of the suction bell 20, excessive vibrations generated in the partial flow rate region of the pump can be suppressed. The fins 18 do not necessarily have to be provided at equal intervals on the inner peripheral surface of the suction bell 20, and even if the intervals are not equal, the swirl component of the reverse flow generated near the pump impeller inlet 23 a can be prevented to some extent, and the partial flow rate region of the pump Can suppress a large vibration speed (excessive vibration).

    FIG. 15 is a view showing a side sectional structure of the axial flow pump according to the present invention. As shown in the figure, the axial flow pump includes a pump casing 27, a suction casing 26 is connected to the front end, and a discharge casing 28 is connected to the rear end. Reference numeral 29 denotes a pump impeller (impeller). The pump impeller 29 is fixed to the front end of the main shaft 24 via a hub 30, and the front end of the pump impeller 29 is located near the inner peripheral surface of the pump casing 27. . The liner ring 17 is attached to the inner peripheral surface of the pump casing 27 so as to face the tip of the pump impeller 29.

  In the axial flow pump configured as described above, when the pump impeller 29 is rotated by the rotation of the main shaft 24, the liquid sucked from the suction port of the suction casing 26 passes through the pump casing 27 and is discharged to the discharge casing 28. Even in such an axial flow pump, a part of the liquid flowing into the inlet of the pump impeller 29 in the partial flow rate operation that cannot be discharged from the outlet of the pump impeller 29 is rotated by the pump impeller 29 while the pump impeller 29 rotates. It flows backward from the entrance of the car 29. The reverse flow of the liquid having the swirl component becomes an excessive vibration source in the partial flow rate region of the pump.

  Therefore, in this case, the inner ring surface of the liner ring 17 in the vicinity of the liquid inflow side end portion is equally spaced in the circumferential direction and in the direction of the center of the inlet of the pump impeller 29 (center of the pump casing 27) (see FIG. 5). A plurality of fins 18 are provided to prevent a reverse flow swirl component of the flow. FIG. 16 is an enlarged view of a portion A in FIG. Thus, by providing a plurality of fins at equal intervals in the circumferential direction of the liquid inflow side end portion of the liner ring 17, the reverse flow swirl component of the liquid flow is blocked by the plurality of fins 18, so that the partial flow rate region of the pump Can suppress the large vibration speed generated.

  The plurality of fins 18 may be provided in a direction inclined by a predetermined angle with respect to the inlet center of the pump impeller 29 (center of the pump casing 27) as shown in FIG. Thereby, the flow of the liquid flowing into the pump impeller 29 is made uniform, and the excessive vibration speed generated in the partial flow rate region of the pump can be suppressed.

  As shown in FIGS. 8 and 9, the fin 18 is reinforced by providing the inner end of the plurality of fins 18, and the pump 18 does not vibrate due to the liquid flow flowing into the impeller 29. It is possible to further improve the effect of suppressing excessive vibration generated in the partial flow rate region. Further, the fins 18 do not necessarily have to be provided at equal intervals in the circumferential direction of the liquid inflow side ends of the liner rings 17, 17, and can prevent the swirl component of the reverse flow generated near the pump impeller inlet to some extent even at unequal intervals, A large vibration speed (excessive vibration) generated in the partial flow rate region of the pump can be suppressed.

  Further, in the above example, the example in which the plurality of fins 18 are provided at equal intervals in the circumferential direction of the liquid inflow side end portion of the liner ring 17 is shown. However, when the liner ring 17 is not provided as shown in FIG. A plurality of fins 18 may be provided directly at equal intervals in the circumferential direction on the inner peripheral surface of the pump casing 27 in the vicinity of the liquid inflow side end. As described above, even when the plurality of fins 18 are directly provided on the inner peripheral surface of the pump casing 27, it is possible to suppress the excessive speed generated in the partial flow rate region of the pump. The fins 18 do not necessarily have to be provided on the inner peripheral surface of the pump casing 27 at equal intervals in the circumferential direction, and even if the intervals are not equal, the swirl component of the reverse flow generated near the pump impeller inlet can be prevented to some extent, and the partial flow rate of the pump A large vibration speed (excessive vibration) generated in the region can be suppressed.

  FIG. 18 is a diagram showing a front cross-sectional configuration of a main part of a double suction centrifugal pump which is an example of a centrifugal pump according to the present invention, and FIG. 19 is a diagram showing a configuration of a liner ring portion. This dual suction centrifugal pump is different from the dual suction centrifugal pump shown in FIG. 4 in that the peripheral diameter of the impeller inlet 13a is equidistant as shown in FIG. This is that a plurality of rectifying plates 31 for rectifying the liquid flow flowing into the impeller inlet in a direction inclined by a predetermined angle with respect to the direction is provided.

  As described above, a plurality of rectifications for rectifying the liquid flow flowing into the impeller inlet 13a at equal intervals in the circumferential direction of the liquid inflow side end portion of the liner ring 17 and in a direction inclined at a predetermined angle with respect to the outer peripheral side radial direction of the impeller inlet. By providing the plate 31, the flow of the liquid flowing into the impeller 13 is made uniform, and the pump performance is improved.

  FIG. 20 is a diagram showing a front sectional configuration of a main part of a double suction centrifugal pump which is an example of a centrifugal pump according to the present invention, and FIG. 21 is a diagram showing a configuration of a liner ring portion. This double suction centrifugal pump is different from the double suction centrifugal pump shown in FIG. 18 in that the flow straightening plates 31 are provided at the liquid flow side end portions of the flow straightening plates 31 provided in the circumferential direction of the liquid flow side end portions of the liner ring 17. This is the point that a reinforcing ring 32 for reinforcing 31 is provided.

  By providing the reinforcing ring 32 at the liquid inflow side end portions of the plurality of rectifying plates 31 as described above, the rectifying plate 31 is reinforced, and vibration or the like is generated in the rectifying plate 31 due to the liquid flow flowing into the impeller 13. Since the flow of the liquid flowing into the impeller 13 is uniform, the pump performance is further improved. 18 to 21, the plurality of rectifying plates 31 are provided at equal intervals in the circumferential direction of the liquid inflow side end of the liner ring 17, but it is not always necessary to provide them at equal intervals. The flow of the liquid flowing into the impeller 13 is made uniform even though the intervals are not uniform, and the pump performance is improved.

  FIG. 22 is a diagram showing a front sectional configuration of a main part of a double suction centrifugal pump which is an example of a centrifugal pump according to the present invention, and FIG. 23 is a diagram showing a configuration of a liner ring portion. This double suction centrifugal pump is different from the dual suction centrifugal pump shown in FIG. 18 in that the circumferential direction of the liquid inflow side end portion of the liner ring 17 is equidistant as shown in FIG. This is that a plurality of countercurrent swirl component preventing / rectifying plates 33 are provided which have an effect of preventing the countercurrent swirling component of the liquid flow and a function of rectifying the liquid flow in a direction inclined by a predetermined angle with respect to the outer peripheral side radial direction.

  By providing the backflow swirl component preventing / rectifying plate 33 in the direction inclined at a predetermined angle with respect to the radial direction of the impeller inlet 13a at equal intervals in the circumferential direction of the liquid inflow side end portion of the liner ring 17 as described above, The excessive vibration speed in the partial flow rate region of the pump is suppressed, and the pump performance is improved.

  FIG. 24 is a diagram showing a front sectional configuration of a main part of a double suction centrifugal pump which is an example of a centrifugal pump according to the present invention, and FIG. 25 is a diagram showing a configuration of a liner ring portion. 22 is different from the both suction centrifugal pumps shown in FIG. 22 in that a reinforcing ring 34 for reinforcing the backflow swirl component preventing / rectifying plate 33 is provided at the inner end of the plurality of backflow swirling component preventing / rectifying plates 33. It is a point provided.

  By providing the reinforcing ring 34 at the inner end of the backflow swirl component preventing / rectifying plate 33 as described above, the backflow swirling component preventing / rectifying plate 33 is reinforced, and the backflow swirling component preventing / current preventing function is achieved by the liquid flow flowing into the impeller 13. The action of suppressing excessive vibration in the partial flow rate region of the pump and the pump performance are further improved without generating vibration or the like in the rectifying plate 33. 20 to 25, a plurality of backflow swirl component preventing / rectifying plates 33 are provided at equal intervals in the circumferential direction of the liquid inflow side end portion of the liner ring 17, but are not necessarily equal intervals. The reverse flow swirl component of the liquid flow flowing into the impeller 13 is prevented, and the liquid flow is rectified to suppress excessive vibration in the partial flow rate region of the pump. Action and pump performance are improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various centrifuges are included within the scope of the technical idea described in the claims and the specification and drawings. Applicable to pumps, mixed flow pumps and axial flow pumps.

It is a front sectional view (BB section of Drawing 2) of the conventional both suction centrifugal pump. FIG. 2 is a side view of a conventional double suction centrifugal pump (viewed in the direction of arrow A in FIG. 1). It is a figure which shows the test result of the both suction vortex pump which concerns on this invention, and the conventional both suction vortex pump. It is sectional drawing which shows the structural example of the principal part of the both suction centrifugal pump which concerns on this invention. It is a figure which shows the structural example of the liner ring part of the both suction vortex pump shown in FIG. It is a figure which shows the structural example of the liner ring part of the both suction vortex pump shown in FIG. It is sectional drawing which shows the structural example of the principal part of the both suction centrifugal pump which concerns on this invention. It is a figure which shows the structural example of the liner ring part of the both suction vortex pump shown in FIG. It is a figure which shows the structural example of the liner ring part of the both suction vortex pump shown in FIG. It is sectional drawing which shows the structural example of the principal part of the both suction centrifugal pump which concerns on this invention. It is sectional drawing which shows the structural example of the principal part of the both suction centrifugal pump which concerns on this invention. It is sectional drawing which shows the structural example of the mixed flow pump which concerns on this invention. It is an enlarged view of the A part of FIG. It is sectional drawing which shows the pump impeller front-end | tip part of the mixed flow pump which concerns on this invention. It is sectional drawing which shows the structural example of the axial flow pump which concerns on this invention. It is an enlarged view of A part of FIG. It is sectional drawing which shows the pump impeller front-end | tip part of the axial flow pump which concerns on this invention. It is sectional drawing which shows the structural example of the principal part of the both suction centrifugal pump which concerns on this invention. It is a figure which shows the structural example of the liner ring part of the both suction vortex pump shown in FIG. It is sectional drawing which shows the structural example of the principal part of the both suction centrifugal pump which concerns on this invention. It is a figure which shows the structural example of the liner ring part of the both suction vortex pump shown in FIG. It is sectional drawing which shows the structural example of the principal part of the both suction centrifugal pump which concerns on this invention. It is a figure which shows the structural example of the liner ring part of the both suction vortex pump shown in FIG. It is sectional drawing which shows the structural example of the principal part of the both suction centrifugal pump which concerns on this invention. It is a figure which shows the structural example of the liner ring part of the both suction vortex pump shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pump casing 11 Suction casing part 12 Discharge casing part 13 Impeller 14 Main shaft 15 Bearing 16 Shaft seal part 17 Liner ring 17a Jaw part 18 Fin 19 Reinforcement ring 20 Suction bell 21 Discharge bowl 22 Discharge pipe 23 Pump impeller (impeller)
24 Main shaft 25 Hub 26 Suction casing 27 Pump casing 28 Discharge casing 29 Pump impeller (impeller)
30 Hub 31 Current plate 32 Reinforcement ring 33 Backflow swirl component prevention and current plate 34 Reinforcement ring

Claims (10)

In a centrifugal pump comprising a pump casing and an impeller, and a liner ring interposed between the pump casing and the impeller inlet,
A plurality of fins for preventing a counter-current swirling component of the liquid flow in the circumferential direction of the liquid inlet side of the liner ring in the central direction of the impeller inlet or in a direction inclined by a predetermined angle with respect to the central direction are provided. Centrifugal pump. The centrifugal pump according to claim 1,
A centrifugal pump characterized in that a reinforcing ring for reinforcing the fins is provided at inner ends of the plurality of fins. In a centrifugal pump comprising a pump casing and an impeller, and a liner ring interposed between the pump casing and the impeller inlet,
A liquid inflow end portion of the liner ring is formed with a jaw portion that protrudes from the liquid inflow side end portion of the impeller inlet to a liquid inflow side at a predetermined angle and has an inclined surface inclined toward the impeller inlet side. A centrifugal pump comprising a plurality of fins for preventing a counter-current swirling component of the liquid flow in a central direction of the impeller inlet or in a direction inclined at a predetermined angle with respect to the central direction in a circumferential direction of the liquid inflow side end of the portion . The centrifugal pump according to claim 3,
A centrifugal pump characterized in that a reinforcing ring for reinforcing the fins is provided at inner ends of the plurality of fins. In a mixed flow pump or an axial flow pump comprising a pump casing and an impeller, and with or without a liner ring interposed between the pump casing and the impeller,
Prevents a reverse flow swirl component of the liquid flow in the central direction of the impeller inlet or in the direction inclined at a predetermined angle with respect to the inner peripheral surface of the liner ring or the inner peripheral surface of the pump casing in the vicinity of the impeller liquid inflow side end. A mixed flow pump or an axial flow pump comprising a plurality of fins. The mixed flow pump or axial flow pump according to claim 5,
A mixed flow pump or an axial flow pump, wherein a reinforcing ring for reinforcing the fins is provided at inner ends of the plurality of fins. In a centrifugal pump comprising a pump casing and an impeller, and a liner ring interposed between the pump casing and the impeller inlet,
A plurality of rectifying plates for rectifying a liquid flow flowing into the impeller inlet in a direction inclined at a predetermined angle with respect to a radial direction on an outer peripheral side of the impeller inlet in a circumferential direction of the liquid inflow side of the liner ring. And centrifugal pump. The centrifugal pump according to claim 7,
A centrifugal pump comprising a reinforcing ring that reinforces the current plate at the liquid inflow side end of the plurality of current plates. In a centrifugal pump comprising a pump casing and an impeller, and a liner ring interposed between the pump casing and the impeller inlet,
A plurality of components that prevent a reverse flow swirl component in a direction inclined at a predetermined angle with respect to the inner circumferential side and the outer circumferential side of the impeller inlet in the circumferential direction of the liquid inlet side of the liner ring and rectify the liquid flow. A centrifugal pump characterized in that a backflow swirl component preventing / rectifying plate is provided. The centrifugal pump according to claim 9,
A centrifugal pump characterized in that a reinforcing ring for reinforcing the backflow swirl component preventing / rectifying plate is provided at an inner end of the plurality of backflow swirling component preventing / rectifying plates.

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