CN115199594A - A jet self-priming pump - Google Patents

Abstract

The invention discloses a jet self-priming pump, which comprises a pump shell and an impeller, wherein the impeller is rotatably arranged on one side in the pump shell, a circulation cavity for jet circulation is arranged in the pump shell, a jet device assembly is arranged in the circulation cavity, the jet device assembly is provided with a jet pipe fixedly arranged in the pump shell, the jet pipe is arranged along the axis of the pump, the tail end of the jet pipe is opposite to the center of the impeller, the front end of the jet pipe is connected with a front guide pipe, an inducer is arranged in the front guide pipe, the inducer is provided with a shaft body, the outer wall of the shaft body is spirally and circularly provided with a plurality of spiral blades, and a driving shaft of the impeller penetrates through the jet pipe along the axis of the pump and extends into the front guide pipe to be connected with the shaft body of the inducer. Because the liquid on the hub side is pressed outwards under the action of centrifugal force, bubbles are pressed to be controlled at the local part of the outer edge and are condensed in the inducer, the whole central flow passage is not easy to be blocked, the overflowing effect is effectively enhanced, the cavitation allowance of the pump can be reduced, the cavitation resistance is improved, the pumping efficiency is improved, and the noise is reduced.

Description

A jet self-priming pump

technical field

The invention relates to the technical field of self-priming pumps, in particular to a jet self-priming pump.

Background technique

Self-priming pumps have the characteristics of high lift, convenient start, wide applicability and simple operation, and are widely used in industrial, agricultural, construction and domestic water supply and other occasions. Compared with self-priming centrifugal pumps such as gas-liquid mixing type, as shown in Figure 1, the jet self-priming pump directly connects the impeller inlet pipe and the jet device, and integrates the jet device inside the pump body. It has good suction performance and is easy to install and maintain, so it is widely used.

However, because the central jet has the characteristics of small surface area of high-speed jet, large pressure drop of the jet tube, short length and easy flow separation, the jet self-priming pump using the central jet device often has high dead point lift, narrow high-efficiency area, Problems such as large flow cavitation, steep lift and power curves (large slope), etc., especially when operating under large flow conditions, are often prone to cavitation, vibration and flow interruption. In view of the above, we propose a jet self-priming pump to solve the above problems.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the above technical defects, and to provide a jet self-priming pump with reasonable structure, good anti-cavitation performance, reduced energy loss, improved pump efficiency, reduced noise and good use effect.

In order to solve the above technical problems, the technical solution provided by the present invention is: a jet self-priming pump, including a pump casing and an impeller, the impeller is rotatably arranged on one side of the inside of the pump casing, and the inside of the pump casing is provided with a circulation cavity for jet circulation, and the circulation There is an ejector assembly in the cavity, and the ejector assembly has a jet pipe fixed in the pump casing. The jet pipe is arranged along the axis of the pump and its end is facing the center of the impeller. The front end of the jet pipe is connected with a front conduit. There is an inducer wheel in the front conduit, the inducer wheel has a shaft body, the outer wall of the shaft is spirally surrounded by a plurality of helical blades, and the drive shaft of the impeller extends through the jet pipe along the axis of the pump to the front conduit It is connected with the shaft body of the inducer, and the outer edge outlet of the impeller communicates with the circulation cavity through the guide vane cavity.

Further, the ejector assembly also includes an inlet structure, the inlet structure includes an inlet cavity surrounded between the front conduit and the injection pipe, the side wall of the pump casing is provided with an inlet pipe, one end of the inlet pipe is connected to the water inlet end. connected, and the other end communicates with the inlet.

Further, a constricted section is provided at one end of the front conduit near the injection pipe.

Further, the diameter of the side close to the inlet port of the injection pipe is smaller than the diameter of the side close to the impeller to form a Venturi tube structure.

Further, three spiral blades are arranged around the outer periphery of the shaft in a circular array, and the width of the flanks of the helical blades away from the constricted section is smaller than the width of the flanks near the constricted section.

Further, the top of the circulation cavity is connected with a water outlet pipe, one side of the water outlet pipe is connected with a water injection hole, and one side of the circulation strong bottom is provided with a drainage hole, and the water injection hole and the drainage hole are screwed with wire plugs.

Compared with the prior art, the present invention has the advantages that an inducer wheel is added in the front duct at the front end of the injection pipe, and the inducer wheel is driven to rotate by the rotation of the impeller, and the inducer wheel is an axial flow impeller. The outer edge of the wheel produces air bubbles. During the movement of the air bubbles to the rear side in the axial direction, the air bubbles are pressure-controlled at the outer edge and condense in the inducer due to the outward pressure of the liquid on the hub side under the action of centrifugal force. Therefore, it is not easy to cause the entire central flow channel to be blocked, effectively enhancing the overcurrent effect, and can reduce the cavitation allowance of the pump, improve the anti-cavitation performance, improve the pumping efficiency, and reduce noise.

Description of drawings

FIG. 1 is a schematic structural diagram of a jet self-priming pump in the prior art.

2 is a schematic structural diagram of a jet self-priming pump of the present invention.

Figure 3 is a schematic diagram of the structure of the inducer of the present invention.

As shown in the figure: 1. Pump casing; 2. Impeller; 3. Circulation cavity; 4. Ejector assembly; Blade; 10, drive shaft; 11, guide vane cavity; 12, inlet cavity; 13, inlet pipe; 14, necked section; 15, outlet pipe; 16, water injection hole; 17, drainage hole.

Detailed ways

The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Wherein the same parts are denoted by the same reference numerals.

In the description of the present invention, it should be understood that the terms "center", "lateral", "top", "bottom", "left", "right", "vertical", "horizontal", "top", The orientation or positional relationship indicated by "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated device. Or elements must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise specified, "plurality" means two or more. Additionally, the term "comprising" and any variations thereof are intended to cover non-exclusive inclusion.

A jet self-priming pump, as shown in Figure 1, includes a pump casing 1 and an impeller 2. The impeller 2 is rotatably arranged on one side of the inside of the pump casing 1. The inside of the pump casing 1 is provided with a circulation cavity 3 for jet circulation. The impeller 2 passes through The motor is driven to run, and the circulation chamber 3 is provided with an ejector assembly 4, the ejector assembly has an injection pipe 5 fixedly arranged in the pump casing 1, the injection pipe 5 is arranged along the axis of the pump and its end faces the impeller 2 When the impeller 2 rotates, a negative pressure is generated in the center of the impeller 2 to absorb the liquid in the injection pipe 5, and then the impeller 2 is rotated and pressurized to be thrown out from the outer edge of the impeller 2.

The front end of the injection pipe 5 is connected with a pre-pipe 6, and the inlet structure includes an inlet cavity 12 surrounded between the pre-pipe 6 and the injection pipe 5. The diameter of the side of the injection pipe 5 close to the inlet cavity 12 is smaller than the diameter of the side close to the impeller 2. Venturi structure. The outer edge outlet of the impeller 2 and the circulation cavity 3 are communicated through the guide vane cavity 11; the high-pressure and high-speed liquid thrown out by pressurization enters the guide vane cavity 11, and enters the circulation cavity 3 through the guide vane cavity 11, and then goes to the guide vane cavity 11. The end of the pre-pipe 6 in the low pressure area flows and is sucked into the injection pipe 5 through the pre-pipe 6 again. Since the jet pipe 5 has a venturi-shaped structure, a sufficient low pressure is formed at the inlet chamber 12 to attract the liquid connected to the inlet pipe 13 to enter into and form self-priming, so that a circulation of liquid flow is formed in the pump casing 1, and the continuously circulating liquid flow passes through The injection pipe 5 forms a negative pressure to suck in the liquid from the inlet pipe 13 for supplementation, and when the liquid flow circulates, the water outlet pipe 15 can be opened to pump the liquid outward. The ejector assembly 4 also includes an inlet structure. An inlet pipe 13 is provided through the side wall of the pump casing 1 . One end of the inlet pipe 13 is connected to the water inlet end, and the other end is communicated with the inlet chamber 12 . The top of the circulation cavity 3 is connected with a water outlet pipe 15, one side of the water outlet pipe 15 is connected with a water injection hole 16, and one side of the circulation strong bottom is provided with a drainage hole 17, and the water injection hole 16 and the drainage hole 17 are screwed with wires. Blocking.

As an improvement, as shown in Figures 2 and 3, an inducer 7 is provided in the front conduit 6, the inducer 7 has a shaft 8, and the outer wall of the shaft 8 is spirally surrounded by a plurality of helical blades 9. The impeller 2 The drive shaft 10 extends through the jet pipe 5 along the axis of the pump to the front conduit 6 and is connected to the shaft body 8 of the inducer 7. In actual use, the impeller 2 rotates through the drive shaft 10 that drives the impeller 2 and drives the inducer 7 at the same time. During rotation, the helical blades 9 are arranged around the outer circumference of the shaft body 8 in a circular array with three pieces.

The jet self-priming pump includes the main flow components such as the ejector, the centrifugal impeller 2, the guide vane cavity 11, etc. The ejector device is installed before the inlet of the impeller 2, and the ejector assembly 4 is used to achieve high-speed jetting effect. The momentum and energy exchange of the pump form a low pressure at the inlet of the pump to achieve self-priming.

In the present invention, a newly designed three-blade inducer 7 matching the original model impeller 2 is added in front of the ejector assembly 4 , as shown in FIG.

In the present invention, a three-blade inducer 7 is added in front of the ejector nozzle, which belongs to the axial flow impeller 2, and has the geometric characteristics and cavitation characteristics of the axial flow impeller 2. There is no centrifugal impeller 2 that promotes the separation of liquid and bubbles. of centrifugal force. In this way, the air bubbles generated at the outer edge of the inducer 7 (where the relative speed is the largest), during the process of moving forward in the axial direction, the air bubbles are pressed due to the outward pressure of the liquid on the hub side under the action of centrifugal force. It is controlled locally at the outer edge and condensed in the inducer 7, so it is not easy to cause blockage of the entire flow channel. The performance of its external characteristics is that the performance declines slowly during the cavitation process, and there is no obvious sudden decline stage. The cavitation on the outer edge is compressed, so that the outer edge moves along the axial direction, and collapses after reaching the high pressure area, which greatly limits the development of the cavitation and avoids the influence of the cavitation phenomenon on the overcurrent parts. The lift generated by the inducer 7 reduces the NPSH of the pump and improves the anti-cavitation performance of the pump, thereby improving performance, increasing efficiency and reducing noise.

The present invention and the embodiments thereof have been described above, and the description is not restrictive. The specific embodiments show only a part of the embodiments of the present invention, rather than all the embodiments, and the actual structure is not limited thereto. All in all, if those of ordinary skill in the art are inspired by it, and without departing from the purpose of the present invention, any structural modes and embodiments similar to this technical solution are designed without creativity, all should belong to the protection scope of the present invention.

Claims (6)

1. The utility model provides a efflux self priming pump, includes pump case (1), impeller (2), and impeller (2) rotate to set up in the inside one side of pump case (1), its characterized in that, and pump case (1) is inside to be equipped with and to be used for the circulating chamber (3) of efflux circulation, is equipped with ejector assembly (4) in circulating chamber (3), ejector assembly has fixed injection pipe (5) of setting in pump case (1), and injection pipe (5) set up and its end is just to impeller (2) center along the axis of pump, and injection pipe (5) front end is connected and is equipped with leading pipe (6), is equipped with inducer (7) in leading pipe (6), inducer (7) have axis body (8), and axis body (8) outer wall spiral is around being equipped with multi-disc helical blade (9), drive shaft (10) of impeller (2) pass injection pipe (5) along the axis of pump and extend to and be connected with the axis body (8) of inducer (7) in leading pipe (6), through guide vane chamber (11) intercommunication between the outer fringe export of impeller (2) and circulating chamber (3).

2. The jet self-priming pump according to claim 1, wherein the jet assembly (4) further comprises an inlet structure, the inlet structure comprises an inlet cavity (12) surrounding between the front guide pipe (6) and the jet pipe (5), an inlet pipe (13) is arranged on the side wall of the pump shell (1) in a penetrating manner, one end of the inlet pipe (13) is connected with the water inlet end, and the other end of the inlet pipe is communicated with the inlet cavity (12).

3. A fluidic self-primer pump according to claim 2, characterized in that the end of the foreline (6) close to the ejector tube (5) is provided with a neck section (14).

4. A fluidic self-primer pump according to claim 2, characterized in that the diameter of the side of the ejector tube (5) close to the inlet chamber (12) is smaller than the diameter of the side close to the impeller (2) to form a venturi structure.

5. A fluidic self-primer pump according to claim 3, characterized in that the helical blade (9) is provided in three pieces in a circumferential array around the shaft body (8), and the width of the flank of the helical blade (9) away from the neck section (14) is smaller than the width of the flank close to the neck section (14).

6. The jet flow self-priming pump according to any one of the claims 1 to 5, wherein the top of the circulation cavity (3) is connected with a water outlet pipe (15), one side of the water outlet pipe (15) is connected with a water injection hole (16), one side of the bottom of the circulation cavity is provided with a water discharge hole (17), and the water injection hole (16) and the water discharge hole (17) are both screwed with plugs.

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