JP2018204566A - Self-priming centrifugal pump - Google Patents

Abstract

To provide a self-priming centrifugal pump capable of improving self-priming performance with a simple structure.SOLUTION: A self-priming centrifugal pump comprises an impeller, and a pump casing storing the impeller. In the pump casing, provided is a gas-liquid separation chamber configured to separate fluid discharged from the impeller during self-priming operation into liquid and gas. The pump casing has a guide part arranged between the gas-liquid separation chamber and the impeller so as to guide fluid. The guide part comprises a flow passage having an inlet opened to the inside of the gas-liquid separation chamber so as to receive part of swirl flow of the liquid in the gas-liquid separation chamber, and outlet opened toward an outer peripheral part of the impeller, wherein the inlet is arranged on an upstream side of the swirl flow with respect to the outlet.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a self-priming centrifugal pump.

  In the centrifugal pump, the liquid transferred by the pump is taken in from the suction port of the casing in which the impeller is accommodated, is given centrifugal force by the impeller, and is sent out from the discharge port of the casing to the discharge pipe. In the casing, a guide portion can be provided that forms a flow path for efficiently discharging the liquid given centrifugal force by the impeller. The guide portion is, for example, a diffuser member having a diffuser flow path formed substantially radially around the impeller, or a partition wall disposed in the casing so as to form a spiral volute chamber around the impeller It may be.

  The self-priming centrifugal pump is a pump having a function of sucking up and discharging the air in the suction pipe connected to the suction port of the casing simultaneously with the activation of the pump. The inside of the suction pipe is filled with water rising in the suction pipe as the air is discharged. Thus, in the self-priming centrifugal pump, normal operation of the pump is started by automatically supplying priming water to the pump.

  FIG. 7 is a side sectional view showing a configuration example of a conventional self-priming centrifugal pump 1. Referring to FIG. 7, the self-priming centrifugal pump 1 includes an impeller 2 and a pump casing 3 that houses the impeller 2. The pump casing 3 includes the impeller 2 during the self-priming operation. A gas-liquid separation chamber 4 is provided for separating the fluid discharged from the liquid into a liquid and a gas. Moreover, the pump casing 3 has a guide part disposed between the gas-liquid separation chamber 4 and the impeller 2 so as to guide the fluid. In the illustrated example, the guide portion is a diffuser member 5.

  During the first operation after the pump is installed, water is supplied from the outside into the suction chamber 6 of the pump casing 3 through a water inlet (not shown). When the impeller 2 rotates at the start of the pump, water in the suction chamber 6 is sucked into the impeller 2. The water discharged from the impeller 2 moves to the gas-liquid separation chamber 4 in the pump casing 3 through the diffuser flow path 5a of the diffuser member 5. Along with this, air in a suction pipe (not shown) connected to the suction port 7 is sucked up and becomes bubbles in the impeller 2 and mixed into water. In the gas-liquid separation chamber 4, only air is discharged from the discharge port 8 of the pump casing 3 to the discharge pipe (not shown) due to the difference in specific gravity. Water is returned from the gas-liquid separation chamber 4 to the impeller 2 and circulates in the pump casing 3.

  In the conventional example shown in the drawing, as a flow path for returning water after gas-liquid separation to the impeller 2, the diffuser member 5 has a substantially axial direction (in other words, an impeller in a position near the outlet side of the impeller 2. A through hole 9 extending in a direction parallel to the rotating shaft 2a of the vehicle 2 is formed. Specifically, the diffuser member 5 has a side wall portion 5c disposed on the front side of the impeller 2 (in other words, the side close to the suction chamber 6), and the through hole 9 has the side wall portion 5c. Formed through. In FIG. 7, 10 is a motor, 11 is a bracket provided between the pump casing 3 and the rotating shaft 2 a of the impeller 2, and 12 is a check valve for preventing the backflow of fluid from the suction chamber 6. Show.

FIG. 8 is a view showing the inside of the self-priming centrifugal pump 1 during the self-priming action, and is a view of the impeller 2 and the diffuser member 5 in the pump casing 3 as seen from the front side of the impeller 2. An arrow F indicates a fluid flow in the gas-liquid separation chamber 4. As described above, the air in the suction pipe is sucked into the suction chamber 6 during the self-priming action. The sucked air is collected on the inner peripheral side of the impeller 2, becomes bubbles in the impeller 2, enters the water, and is discharged into the gas-liquid separation chamber 4 together with the water. Therefore, in order to perform a good self-priming action, the low-density air present on the inner peripheral side of the impeller 2 is removed from the impeller 2.
It must be carried on a flow of dense water in which the centrifugal force of the outer periphery of the tube is acting.

  It is known that a bubble group is formed between the outlet side of the rotating impeller 2 and the diffuser member 5 during the self-priming action. By discharging as many bubbles as possible from the impeller 2 together with water, it is possible to efficiently discharge the air in the suction pipe and shorten the time until the normal operation of the pump is started. In the illustrated conventional example, the water in the gas-liquid separation chamber 4 is returned to the outlet side of the impeller 2 through an axial through hole 9 provided in the diffuser member 5. In this way, the air bubbles are pushed out from the diffuser member 5 by the water returned from the gas-liquid separation chamber 4, and the self-priming action is promoted. In FIG. 8, the side wall 5c of the diffuser member 5 is omitted, and only the position of the through hole 9 is shown. An arrow R indicates the direction of rotation of the rotating shaft 2a of the impeller 2. During the self-priming action, the water in the gas-liquid separation chamber 4 is circulated in the pump casing 3 while forming a swirling flow around the rotating shaft 2 a without being discharged from the pump casing 3. The flow direction F of the swirling flow is the same as the rotation direction R of the rotating shaft 2a.

  The formation of a return flow path such as the through hole 9 is described in Patent Document 1, for example.

Japanese Utility Model Publication No. 52-38601

  An object of one embodiment of the present invention is to provide a self-priming centrifugal pump capable of improving self-priming performance with a simple configuration.

  According to one embodiment of the present invention, a self-priming centrifugal pump comprising an impeller and a pump casing that houses the impeller, is discharged from the impeller into the pump casing during the self-priming operation. A gas-liquid separation chamber for separating the fluid into liquid and gas is provided, and the pump casing has a guide portion disposed between the gas-liquid separation chamber and the impeller so as to guide the fluid. And the guide portion includes an inlet opening in the gas-liquid separation chamber so as to receive a part of the swirling flow of the liquid in the gas-liquid separation chamber, and an outlet opening toward the outer peripheral portion of the impeller. A self-priming centrifugal pump is provided in which the inlet is disposed at a position upstream of the swirling flow with respect to the outlet.

It is a fragmentary sectional side view which shows an example of the self-priming centrifugal pump by 1st Embodiment of this invention. It is a figure which shows the inside of the pump in self-priming action in the self-priming centrifugal pump of 1st Embodiment. It is a figure for demonstrating arrangement | positioning of the entrance and exit of a flow path. It is a sectional side view which shows an example of the self-priming centrifugal pump by 2nd Embodiment of this invention. It is a figure which shows the inside of the pump in self-priming action in the self-priming centrifugal pump of 2nd Embodiment. It is a figure corresponding to FIG. 2 which shows an example of the self-priming centrifugal pump by 3rd Embodiment of this invention. It is a figure which shows the experimental result of the self-priming centrifugal pump of 3rd Embodiment. It is a figure which shows the structural example of the flow-path formation part shown in FIG. It is a figure which shows the other structural example of a flow-path formation part. It is a figure which shows the other structural example of a flow-path formation part. It is a figure which shows the other structural example of a flow-path formation part. It is a sectional side view which shows the structural example of the conventional self-priming centrifugal pump. It is a figure which shows the inside of the pump in self-priming action.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the accompanying drawings, the same or similar elements are denoted by the same or similar reference numerals, and redundant description of the same or similar elements may be omitted in the description of each embodiment. Further, the features shown in each embodiment can be applied to other embodiments as long as they do not contradict each other.

[First Embodiment]
FIG. 1 is a partial side sectional view showing an example of a self-priming centrifugal pump 1 according to a first embodiment of the present invention. The self-priming centrifugal pump 1 of the first embodiment includes an impeller 2 and a pump casing 3 that houses the impeller 2, as in the conventional self-priming centrifugal pump 1 shown in FIG. A gas-liquid separation chamber 4 is provided in the pump casing 3 for separating the fluid discharged from the impeller 2 during the self-priming operation into liquid and gas. Moreover, the pump casing 3 includes a diffuser member 5 as a guide portion disposed between the gas-liquid separation chamber 4 and the impeller 2 so as to guide the fluid. The first embodiment is characterized in the configuration of a flow path provided in the guide for returning the liquid in the gas-liquid separation chamber 4 to the vicinity of the exit of the impeller 2. Therefore, FIG. 1 shows only the peripheral configuration of the flow path, and a detailed description of portions common to the above-described prior art is omitted.

  In 1st Embodiment, the diffuser member 5 is provided with the side wall part 5c arrange | positioned at the front side (in other words, the side close | similar to the suction chamber 6) of the impeller 2, and a gas-liquid separation chamber is provided in the side wall part 5c. A flow path forming portion 19 is provided that defines a flow path (in other words, a return flow path) for returning the liquid in 4 to the vicinity of the exit of the impeller 2. The flow path forming portion 19 has an inlet opening 19a (not shown in FIG. 1) that defines the inlet of the flow path and an outlet opening 19b that defines the outlet of the flow path. The inlet opening 19 a opens into the gas-liquid separation chamber 4. Moreover, the exit opening 19b is opened in the position which faces the outer peripheral part of the impeller 2 as FIG. 1 shows. Thereby, the flow of the liquid from the gas-liquid separation chamber 4 can be made to flow out near the exit of the impeller 2. A part of the liquid flowing out in the vicinity of the outlet of the impeller 2 can flow into the inside of the impeller 2 and cause an unbalanced state of pressure at the outer peripheral portion of the impeller 2. In this way, the bubble group which stagnates on the outer peripheral part of the impeller 2 can be efficiently pushed out through the diffuser flow path 5a.

  FIG. 2 is a diagram showing the inside of the self-priming centrifugal pump 1 of FIG. 1 during the self-priming action, and is a view of the impeller 2 and the diffuser member 5 in the pump casing 3 as seen from the front side of the impeller 2. It is. During the self-priming action, the liquid discharged from the diffuser member 5 circulates in the pump casing 3 without being discharged from the pump casing 3. As shown by an arrow F in FIG. 2, this circulating flow forms a strong swirling flow that flows in the same direction as the rotation direction R of the impeller 2. According to the first embodiment, the self-priming action of the self-priming centrifugal pump 1 can be promoted using this swirling flow.

6A is a partial cross-sectional view of the diffuser member 5 shown in FIG. 1 and FIG. 2, when the diffuser member 5 is viewed from the top of FIG. 1 or 2 (in other words, the discharge port 8 side of the pump casing 3). It is a fragmentary sectional view which shows the structure of the flow-path formation part 19. FIG. A gas-liquid separation chamber 4 (not shown) is arranged on the left side of FIG. 6A, and an impeller 2 (not shown) is arranged on the right side of FIG. 6A. The flow path forming unit 19 defines a flow path 19d that allows the inlet opening 19a and the outlet opening 19b to communicate with each other. The direction of the swirling flow passing through the flow path forming unit 19 in the gas-liquid separation chamber 4 is indicated by an arrow F. The direction F in which the swirling flow flows is the same direction as the rotation direction R of the impeller 2. In the first embodiment, for example, as shown in FIG. 6A, the inlet opening 19a (that is, the flow path 19d) of the flow path forming portion 19 is used.
Is disposed at a position upstream of the swirling flow passing through the flow path forming portion 19 with respect to the outlet opening 19b (that is, the outlet of the flow path 19d).

  In this embodiment, the meaning of “position on the upstream side of the swirl flow” is defined using an angle in the rotation direction of the impeller 2. As an example, consider a coordinate system having the origin of rotation of the impeller 2 as shown in FIG. 2A. 2A is a view similar to FIG. 2, showing the impeller 2 and the diffuser member 5 in the pump casing 3 along the axial direction of the impeller 2 from the front side of the impeller 2 during the self-priming action. .

In this coordinate system, a position where the one-dot chain line on the Y-axis is rotated counterclockwise (that is, the rotational direction R of the impeller 2) by an angle α and a position rotated by an angle β are respectively represented by a one-dot chain line P _α. , P _β . The angle β is larger than the angle α (where 0 ° <α <360 °, 0 ° <β <360 °). Angular position P _alpha having such beta-alpha> 0 relationships, the position of P _alpha when there is P _beta, is a position on the upstream side of the swirling flow with respect to P _beta. In the example of FIG. 2A, the positions of the inlet and the outlet of the flow path viewed along the axial direction of the impeller 2 are completely separated in the circumferential direction of the impeller 2 (see FIG. 6A). However, depending on the specific shape of the flow path, the inlet and the outlet may be arranged at positions that partially overlap in the circumferential direction. In other words, the opening range of the inlet and the opening range of the outlet may partially overlap when viewed in plan along the axial direction of the impeller 2.

  Furthermore, the direction of the inlet opening 19a is determined so as to receive a part of the swirling flow in a direction that is not parallel to the axis of the impeller 2 (in other words, a non-parallel direction). In order to show the axial direction of the impeller 2, in FIG. 6A, the line parallel to the axial line of the impeller 2 is shown by dotted line AA. Specifically, as illustrated in FIG. 6A, the flow path 19 d includes a portion (for example, a portion 19 c illustrated in FIG. 6A) that extends from the inlet to the outlet while being inclined with respect to the axis of the impeller 2. be able to. Here, “inclination with respect to the axis of the impeller 2” means not parallel to the axial direction AA, and substantially corresponds to the axial direction AA as shown in FIG. 6A. This includes the case where the orientation is perpendicular to.

  As described above, in the present embodiment, the flow path 19d of the flow path forming unit 19 has a swirl flow with respect to the outlet where the inlet opening in the gas-liquid separation chamber 4 opens toward the outer peripheral portion of the impeller 2. It is disposed at a position on the upstream side of F and includes a portion extending from the inlet to the outlet while being inclined with respect to the axis of the impeller 2. As a result, a part of the swirling flow F flows into the flow path 19d of the flow path forming portion 19 without greatly impairing the strength of the flow.

  In the example of FIG. 6A, the side wall 5c of the diffuser member 5 includes a protrusion 5b protruding into the gas-liquid separation chamber 4, and the inlet opening 19a is formed in the protrusion 5b. The protrusion 5b may be an external member such as an elbow pipe connected to the side wall 5c by welding, or may be molded or cast integrally with the side wall 5c.

  The flow path 19d of the flow path forming portion 19 of the first embodiment flows through the gas-liquid separation chamber 4 as compared with the through hole 9 that extends in the axial direction as a whole as in the conventional example shown in FIGS. A swirl flow can be easily accepted. As shown in FIG. 6A, the swirl flow that has entered the flow path 19 of the flow path forming unit 19 from the inlet opening 19a is supplied to the vicinity of the exit of the impeller 2 without significantly impairing the strength of the flow. Thus, the bubbles can be efficiently pushed out of the diffuser member 5 to the gas-liquid separation chamber 4 by the strong swirl flow. Therefore, the self-priming action of the self-priming centrifugal pump 1 can be promoted.

[Second Embodiment]
FIG. 3 is a side sectional view showing an example of the self-priming centrifugal pump 101 according to the second embodiment of the present invention. FIG. 4 is a view corresponding to FIG. 2 and showing the inside of the self-priming centrifugal pump 101 during the self-priming action. 3 is a cross-sectional view taken along the line BB in FIG. The self-priming centrifugal pump 101 of the second embodiment is a volute type in which a spiral liquid passage (in other words, a volute chamber) 103 a is formed in a pump casing 103. As an example, the illustrated self-priming centrifugal pump 101 is of a double volute type having two volute chambers 103a. Specifically, the self-priming centrifugal pump 101 of FIG. 3 includes an impeller 102 and a pump casing 103 that houses the impeller 102. The pump casing 103 includes a vane during self-priming operation. A gas-liquid separation chamber 104 for separating the fluid discharged from the vehicle 102 into a liquid and a gas is provided. The interior of the pump casing 103 is partitioned by a partition wall (in other words, a volute wall) 103b so as to form a volute chamber 103a around the impeller 102. In the second embodiment, the partition wall 103b forms a guide for guiding the fluid.

  In 2nd Embodiment, the partition 103b is provided with the side wall part 103c arrange | positioned at the front side of the impeller 2, and returns the liquid in the gas-liquid separation chamber 104 to the vicinity of the exit of the impeller 102 to the side wall part 103c. A flow path forming part 119 is provided to define a flow path for this purpose. The flow path forming portion 119 has an inlet opening 119a (reference numeral omitted in FIG. 3) that defines the inlet of the flow path and an outlet opening 119b that defines the outlet of the flow path. The inlet opening 119a opens into the gas-liquid separation chamber 104. Further, as shown in FIG. 3, the outlet opening 119 b opens at a position facing the outer peripheral portion of the impeller 102.

  During the first operation after the pump is installed, water is supplied from the outside into the suction chamber 106 of the pump casing 103 through a water inlet (not shown). When the impeller 102 rotates when the pump is activated, water in the suction chamber 106 is sucked into the impeller 102. The water discharged from the impeller 102 moves to the gas-liquid separation chamber 104 in the pump casing 103 through the volute chamber 103a. Along with this, air in a suction pipe (not shown) connected to the suction port 107 is sucked up and becomes bubbles in the impeller 102 and mixed into water. In the gas-liquid separation chamber 104, only air is discharged from the discharge port 108 of the pump casing 103 to a discharge pipe (not shown) due to the difference in specific gravity, and water is impeller from the gas-liquid separation chamber 104 through the flow path forming unit 119. Returned to the vicinity of the exit of the car 102. In FIG. 3, 110 is a bearing body, 102 a is a rotating shaft of the impeller 102, and 112 is a check valve that prevents the backflow of fluid from the suction chamber 106.

  The liquid flow from the gas-liquid separation chamber 104 can flow out to the vicinity of the outlet of the impeller 102 through the outlet opening 119 b that opens at a position facing the outer peripheral portion of the impeller 102. A part of the liquid flowing out in the vicinity of the exit of the impeller 102 can flow into the impeller 102 and cause an unbalanced state of pressure on the outer peripheral portion of the impeller 102. In this way, the bubble group stagnating on the outer peripheral portion of the impeller 102 can be efficiently pushed out of the volute chamber 103a.

  As shown in FIG. 4, during the self-priming action, the liquid discharged from the volute chamber 103 a circulates in the pump casing 103 without being discharged from the pump casing 103. As shown by the arrow F in FIG. 4, this circulating flow forms a strong swirling flow that flows in the same direction as the rotation direction of the impeller 102. According to the second embodiment, as in the first embodiment, the self-priming action of the self-priming centrifugal pump 101 can be promoted using this swirling flow. The configuration of the flow path forming unit 119 is substantially the same as the configuration of the flow path forming unit 19 shown in FIG. 6A with respect to the first embodiment.

[Third Embodiment]
FIG. 5 is a view corresponding to FIG. 2 and showing a self-priming centrifugal pump 201 according to the third embodiment. The self-priming centrifugal pump 201 of the third embodiment is substantially the same as the self-priming centrifugal pump 1 of the first embodiment except that a baffle 203a is provided in the pump casing 203. A baffle 203a as shown in FIG. 5 may be provided so as to suppress the generation of an excessive swirl flow. When the baffle 203a is provided, it is desirable that the outlet opening 219b of the flow path forming portion is separated from the position of the baffle 203a in the rotation direction R of the impeller 202 by a predetermined angle γ. It is desirable that the inlet opening of the flow path forming portion is not far away from the outlet opening 219b in terms of angle. In the third embodiment, only the outlet opening of the flow path forming portion is denoted by reference numeral 219b to indicate its position.

FIG. 5A shows the experimental results for determining the angle γ. For each parameter, the suction height is 5 m, the exit area of the return channel is 176 mm ² , the flow velocity U ₂ is 30 m / sec, 25 m / sec, the self-priming speed is on the vertical axis, and the angle γ is on the horizontal axis. A curve like this was obtained. The vertical axis indicates the ratio of the self-priming rate at each angle γ as a ratio. Here, the ratio of the self-priming rate when the angle γ is −60 degrees is set to 1. From the experimental results, it is understood that the predetermined angle γ is preferably 10 to 220 degrees from the viewpoint of the self-priming speed.

  According to the third embodiment, also in the self-priming centrifugal pump 1 provided with the baffle 203a, a flow path forming portion similar to that in the first and second embodiments can be formed. In addition, as a guide part, it replaces with the diffuser member 5 of 3rd Embodiment, and the partition 103b which forms the volute chamber 103a of 2nd Embodiment may be provided.

[Modification]
In the above-described embodiment, the flow path forming unit 19 having the configuration illustrated in FIG. 6A has been described as a specific example of the flow path forming unit that forms the return flow channel. However, the configuration of the flow path forming unit 19 is illustrated in FIG. 6A. Not limited to. The flow path 19 d of the flow path forming unit 19 is arranged at a position upstream of the swirl flow F with respect to the outlet opening of the gas-liquid separation chamber 4 toward the outer peripheral portion of the impeller 2. And a portion extending in an inclined manner with respect to the axis of the impeller 2 from the inlet toward the outlet. In FIG. 6B, the flow path 19 d of the flow path forming portion 19 is entirely linear, and the inlet thereof opens at a substantially flat surface of the side wall portion 5 c of the diffuser member 5. In FIG. 6C, as in FIG. 6B, the flow path 19d of the flow path forming part 19 is entirely linear, but the side wall part 5c of the diffuser member 5 protrudes into the gas-liquid separation chamber 4 (in other words, For example, the protruding portion 5b is formed with an inlet of the flow path 19d. Moreover, in FIG. 6D, the flow path 19d of the flow-path formation part 19 contains a bending part or a curved part similarly to FIG. 6A. The side wall portion 5c of the diffuser member 5 includes a protrusion (in other words, a raised portion) 5b protruding into the gas-liquid separation chamber 4, and an inlet of the flow path 19d is formed in the protrusion 5b.

  In the example of FIGS. 6A to 6D, the flow path cross-sectional area of the flow path forming unit 19 is constant. However, the flow path forming unit 19 may be configured such that the cross-sectional area of the flow path changes, for example, a bell mouth shape or a conical shape.

  In any embodiment of the present invention, the number of flow path forming portions is not particularly limited. However, when the diffuser member 5 is provided as a guide portion, the number is the same as the number of diffuser flow paths 5a. Is preferred.

  In any embodiment of the present invention, the form of the impeller is not particularly limited. Various types of impellers such as a closed type, an open type, and a semi-open type can be used. Also, the form of the guide part is not particularly limited.

The embodiments of the present invention have been described above based on some examples. However, the above-described embodiments of the present invention are for facilitating understanding of the present invention and do not limit the present invention. . The present invention can be changed and improved without departing from the gist thereof, and the present invention naturally includes equivalents thereof. In addition, any combination or omission of each constituent element described in the claims and the specification is possible within a range where at least a part of the above-described problems can be solved or a range where at least a part of the effect is achieved. It is.

The present invention includes the following embodiments.
1. A self-priming centrifugal pump comprising an impeller and a pump casing that houses the impeller,
A gas-liquid separation chamber for separating the fluid discharged from the impeller during the self-priming operation into liquid and gas is provided in the pump casing,
The pump casing has a guide portion disposed between the gas-liquid separation chamber and the impeller so as to guide the fluid,
The guide unit includes a flow path including an inlet opening in the gas-liquid separation chamber so as to receive a part of the swirling flow of the liquid in the gas-liquid separation chamber, and an outlet opening toward the outer peripheral portion of the impeller. A self-priming centrifugal pump in which the inlet is disposed at a position upstream of the swirling flow with respect to the outlet.
2. The flow path includes a portion extending in an inclined manner with respect to the axis of the impeller from the inlet toward the outlet. The self-priming centrifugal pump described in 1.
3. The guide portion includes a side wall portion disposed on the front side of the impeller, and the flow path is provided in the side wall portion. Or 2. The self-priming centrifugal pump described in 1.
4). The side wall portion includes a protruding portion that protrudes into the gas-liquid separation chamber, and the inlet is formed in the protruding portion. The self-priming centrifugal pump described in 1.
5. The flow path is generally linear, as described in 1. above. ~ 4. The self-priming centrifugal pump according to any one of the above.
6). The flow path includes a bent portion or a curved portion, and ~ 4. The self-priming centrifugal pump according to any one of the above.
7). The guide part is a diffuser member that forms a diffuser flow path around the impeller, and ~ 6. The self-priming centrifugal pump according to any one of the above.
8). The guide part is a partition wall that partitions the inside of the pump casing so as to form a volute chamber around the impeller. ~ 6. The self-priming centrifugal pump according to any one of the above.

  The present invention can be widely applied to a self-priming centrifugal pump.

A-A Line F parallel to the axis of the impeller F Swirling flow R Rotating direction of the impeller 1, 101, 201 Self-priming centrifugal pump 2, 102, 202 Impeller 2a, 102a, 202a Rotating shaft 3, 103, 203 Casing 203a Baffle 4, 104 Gas-liquid separation chamber 5, 205 Diffuser member 5a Diffuser flow path 5b Projection portion 5c, 103c Side wall portion 6, 106 Suction chamber 7, 107 Suction port 8, 108 Discharge port 9 Through hole 10 Motor 11 Bracket 12, 112 Check valve 19, 119 Flow path forming portion 19a, 119a Inlet opening 19b, 119b, 219b Outlet opening 19c Inclined portion 19d Flow path 103a Volute chamber 103b Partition 110 Bearing body

Claims (8)

A self-priming centrifugal pump comprising an impeller and a pump casing that houses the impeller,
A gas-liquid separation chamber for separating the fluid discharged from the impeller during the self-priming operation into liquid and gas is provided in the pump casing,
The pump casing has a guide portion disposed between the gas-liquid separation chamber and the impeller so as to guide a fluid,
The guide section includes an inlet that opens into the gas-liquid separation chamber so as to receive a part of the swirling flow of the liquid in the gas-liquid separation chamber, and an outlet that opens toward the outer peripheral portion of the impeller. Has a road,
The inlet is a self-priming centrifugal pump disposed at a position upstream of the swirling flow with respect to the outlet.   The self-priming centrifugal pump according to claim 1, wherein the flow path includes a portion extending from the inlet toward the outlet with an inclination with respect to an axis of the impeller.   The self-priming centrifugal pump according to claim 1 or 2, wherein the guide portion includes a side wall portion disposed on a front side of the impeller, and the flow path is provided in the side wall portion.   4. The self-priming centrifugal pump according to claim 3, wherein the side wall includes a protrusion that protrudes into the gas-liquid separation chamber, and the inlet is formed in the protrusion.   The self-priming centrifugal pump according to any one of claims 1 to 4, wherein the flow path is entirely linear.   The self-priming centrifugal pump according to any one of claims 1 to 4, wherein the flow path includes a bent portion or a curved portion.   The self-priming centrifugal pump according to any one of claims 1 to 6, wherein the guide portion is a diffuser member that forms a diffuser flow path around the impeller.   The self-priming centrifugal pump according to any one of claims 1 to 6, wherein the guide portion is a partition that partitions the interior of the pump casing so as to form a volute chamber around the impeller.

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