Jet type liquid medium output efficient rotary jet pump

Abstract

The invention provides a jet type liquid medium output efficient rotary jet pump. A main shaft is installed in the front end of a shell; a rotor cavity is formed in the rear end of the shell and consists of a rotary shell and a rotary shell cover; an impeller coaxial with the rotor cavity is fixedly mounted at the rear end in the rotor cavity, and a radial channel is formed in the rear side, directly facing the right inner wall of the rotor cavity, of the impeller to facilitate flowing of a liquid medium; the tail end of the spindle is connected with the front end of the rotor cavity through a driving disc to drive the rotor cavity, the impeller and the liquid medium to rotate together; a cover plate and a water inlet and outlet body are sequentially arranged at the rear end of the shell; the shell and the cover plate as well as the cover plate and the water inlet and outlet body are fixedly connected; the rotary shell cover is connected with the water inlet and outlet body through a mechanical sealing assembly. A static collecting pipe is further installed in the rotor cavity, a liquid medium discharging channel is arranged at the bottom of the collecting pipe, and a jet flow assembly is installed. The rotary jet pump is combined with the jet flow assembly, and it is guaranteed that the rotary jet pump obtains relatively large flow during high efficiency and high lift.

Description

Technical Field

[0001] The invention provides a high-efficiency rotary jet pump for outputting jet-type liquid medium, belonging to the technical field of water pumps. Background Art

[0002] The rotary jet pump is a low specific speed centrifugal pump. Through the special design of its internal structure, it converts the inlet fluid into a high-speed rotating vortex, and then sprays the vortex along the axial direction of the equipment to the outlet through the jet energy, thereby achieving the purpose of conveying the fluid. It is mainly used in petrochemical, hydraulic cleaning, boiler water supply, seawater desalination, steel plant descaling, oil field water injection and other industries. It can replace segmental multistage pumps, high-speed pumps, reciprocating pumps, and can overcome their shortcomings. Its seal is at the inlet pressure end, with a good working environment and easy sealing.

[0003] The existing rotary jet pump is mainly composed of three parts: impeller, rotor cavity and manifold. The liquid medium rotates with the impeller to obtain energy when passing through the impeller channel, and then enters the rotor cavity from the impeller outlet; finally, it is output to the pump outlet by the manifold in the rotor cavity. Compared with ordinary extremely low specific speed centrifugal pumps, the impellers of the two are roughly the same. The rotary jet pump has no disc friction loss and volute hydraulic loss, but has more hydraulic loss in the rotor cavity and manifold. That is, the liquid medium produces energy appreciation (impeller head) per unit weight of liquid after passing through the impeller, and generates energy loss in the rotor cavity and manifold after passing through the rotor cavity and manifold.

[0004] The design of the rotor cavity (external flow field of the manifold) and the manifold is particularly important for the mechanical efficiency of the jet pump. At present, the research on the external characteristics of the jet pump mainly focuses on the experimental research and theoretical analysis of the influence of the geometric parameters of the impeller and the manifold on the pump performance. Studies have shown that the working head of the jet pump is high and the flow rate is small. With the increase of the flow rate of the jet pump, the head shows a monotonically decreasing trend, while the efficiency first increases with the flow rate, and then shows a decreasing trend after reaching the maximum value. Therefore, for the flow rate, it is difficult to achieve the optimal head and efficiency at the same time. Summary of the invention

[0005] The technical problem to be solved by the present invention is to solve the problem of optimizing the flow rate, head and efficiency of the rotary jet pump when the flow rate is small. The specific technical solution is:

[0006] A high-efficiency rotary jet pump for jet-type liquid medium output comprises a housing, a main shaft is installed in the front end of the housing through a bearing, a bearing end cover and a bearing box;

[0007] The outer shell is provided with a rotor cavity, which is composed of a rotary shell and a rotary shell cover; an impeller coaxial with the rotor cavity is fixedly installed at the rear end of the rotor cavity; the end of the main shaft is connected to the front end of the rotor cavity through a driving disk;

[0008] The rear end of the shell is provided with a cover plate and an inlet and outlet water body in sequence, the rotating shell cover is connected with the inlet and outlet water body through a mechanical seal assembly, and the rotor cavity rotates relative to the shell and the cover plate under the drive of the main shaft;

[0009] The liquid medium flows through the inlet and outlet of the water body in sequence through the rear radial channel of the impeller facing the right inner wall of the rotor cavity and the rotor cavity;

[0010] A stationary collecting pipe is also installed in the rotor cavity, and the bottom of the collecting pipe is a liquid medium discharge channel, and the liquid medium discharge channel is coaxially installed in the liquid medium inlet channel;

[0011] The liquid medium discharge channel has a plurality of circumferentially distributed openings at the annular channel between the rear side of the impeller and the right inner wall of the rotor chamber, which is the suction port of the liquid medium suction chamber of the jet assembly;

[0012] A jet assembly is installed on the liquid medium discharge channel, and the jet assembly includes a suction chamber, a nozzle and a mixing and expansion chamber; the suction chamber is the horizontal part of the manifold; the nozzle is positioned and installed in the inlet cavity of the suction chamber, and the outlet end of the conical nozzle is facing the throat of the mixing and expansion chamber; the nozzle is a small conical tube structure; the mixing and expansion chamber is an inner conical tube component, and its cone angle is opposite to the cone angle of the nozzle, and the outer wall of the large-diameter rear end of the mixing and expansion chamber is mounted on the liquid medium discharge channel in the inlet and outlet water body; the gradually enlarged structure of the mixing and expansion chamber gradually reduces the speed of the mixed flow, and converts the speed energy into pressure energy.

[0013] The present invention adopts the combination of a rotary jet pump and a jet component. The most obvious advantage is that it can ensure a relatively large flow rate when the rotary jet pump has a high head. In addition, the size of the suction port of the suction chamber of the jet component is reasonably selected, so that the rotary jet pump can operate in the optimal mechanical efficiency range. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic cross-sectional structure diagram of a jet-type liquid medium output high-efficiency rotary jet pump of the present invention;

[0015] Figure 2 It is a layout diagram of the collector, impeller and rotor chamber of the present invention;

[0016] Figure 3 It is a structural schematic diagram of the liquid collecting pipe of the present invention;

[0017] Figure 4 It is a schematic diagram of the outer contour structure of the liquid collecting pipe of the present invention;

[0018] Figure 5 It is a schematic diagram of the enlarged structure of the jet assembly of the present invention;

[0019] Figure 6 It is a schematic diagram of the structure of the jet outlet mixing and expansion chamber of the present invention;

[0020] Figure 7 It is a flow division and confluence route diagram of the liquid medium of the present invention. DETAILED DESCRIPTION

[0021] like Figure 1 As shown, a high-efficiency rotary jet pump for jet-type liquid medium output includes a housing 11, and a main shaft 4 is installed in the front end of the housing 11 through a bearing 2, a bearing end cover 1 and a bearing box 5;

[0022] The housing 11 is provided with a rotor cavity, which is composed of a rotary shell 7 and a rotary shell cover 12; an impeller 9 coaxial with the rotor cavity is fixedly installed at the rear end of the rotor cavity; the end of the main shaft 4 is connected to the front end of the rotor cavity through a driving disk 6;

[0023] The rear end of the housing 11 is provided with a cover plate 13 and an inlet and outlet water body 15 in sequence, the rotary shell cover 12 is connected to the inlet and outlet water body 15 through a mechanical seal assembly 14, and the rotor cavity rotates relative to the housing 11 and the cover plate 13 under the drive of the main shaft 4;

[0024] The liquid medium flows through the inlet of the water inlet and outlet 15 and sequentially through the rear radial channel of the impeller 9 facing the right inner wall of the rotor cavity and the rotor cavity;

[0025] A stationary manifold 8 is also installed in the rotor cavity. The lower end of the manifold 8 is a liquid medium discharge channel, and the liquid medium discharge channel is coaxially installed in the liquid medium inlet channel.

[0026] The liquid medium discharge channel has a plurality of circumferentially distributed openings at the annular channel between the rear side of the impeller 9 and the right inner wall of the rotor chamber, which is the suction port of the liquid medium suction chamber of the jet assembly 10, such as Figure 5 As shown;

[0027] A jet assembly 10 is installed on the liquid medium discharge channel, and the jet assembly 10 includes a suction chamber, a nozzle and a mixing and expansion chamber; the suction chamber is the horizontal part of the collecting pipe 8; the nozzle is positioned and installed in the inlet cavity of the suction chamber, and the outlet end of the conical nozzle is opposite to the throat of the mixing and expansion chamber; the nozzle is a small conical tube structure; the mixing and expansion chamber is an inner conical tube component, and its cone angle is opposite to the cone angle of the nozzle, and the outer wall of the large-diameter rear end of the mixing and expansion chamber is mounted on the liquid medium discharge channel of the inlet and outlet water body 15; the gradually enlarged structure of the mixing and expansion chamber makes the speed of the mixed flow gradually reduce, and the speed energy is converted into pressure energy.

[0028] The present invention adds a suitable jet assembly 10 to the bottom outlet of the manifold of an ordinary rotary jet pump. On the one hand, the jet assembly 10 is used to divert the flow, thereby reducing the flow of the liquid medium entering the rotor cavity, so as to ensure that the flow entering the rotor cavity of the rotary jet pump corresponds to the high efficiency range of the rotary jet pump; on the other hand, the flow diverted by the jet assembly 10 is combined with the high-pressure liquid medium at the outlet of the manifold of the rotary jet pump, thereby increasing the flow of the rotary jet pump. The position of the jet assembly 10 in the rotary jet pump is as follows: Figure 1 shown.

[0029] Figure 1 The power is provided by a diesel engine or an electric motor, which is input from the main shaft 4 and drives the rotor cavity composed of the swirl shell 7 and the swirl shell cover 12, the impeller 9, and the liquid medium in the rotor cavity to rotate together. The rotor cavity, the manifold 8, and the impeller 9 directly interact with the liquid medium. Figure 2 It can be seen that the manifold 8 is an important component for energy conversion of the rotary jet pump. It collects the high-speed rotating liquid medium in the rotor cavity and converts the velocity energy of the liquid medium into pressure energy through the diffusion section. Figure 2 The header position shown in Figure 3 From the shape of the middle manifold, the liquid medium, from entering the manifold nozzle of the rotary jet pump to flowing out from the bottom outlet of the manifold, on the one hand, converts velocity energy into pressure energy through the diffusion section; on the other hand, it undergoes two nearly 90-degree direction changes, which will inevitably cause hydraulic losses. To reduce this part of the loss, in addition to improving the finish of the flow-through components, try to use an excellent hydraulic model. Figure 4 In order to reduce the interaction between the fluid medium in the rotor cavity and the collecting pipe 8, the collecting pipe 8 is made into an airfoil structure.

[0030] The technical solution of the present invention is to install a jet assembly 10 on the liquid medium discharge channel at the bottom of the manifold. Figure 5 This is a 3x magnified image of the jet assembly.

[0031] The jet assembly 10 here is actually a jet pump. Since it is a pump product composed of parts that do not move relative to each other, it is relatively convenient to install it at the outlet of the manifold 8 of an ordinary rotary jet pump. The complete jet assembly 10 includes a suction chamber, a nozzle, a mixing chamber and a flange; and here the suction chamber is the horizontal part at the bottom of the manifold 8; the suction chamber and the mixing chamber are coaxially connected, the nozzle is positioned and installed in the inlet cavity of the suction chamber, and the outlet end of the conical nozzle faces the throat of the mixing chamber. The nozzle is a small conical tube inside the jet assembly 10, and the structure and cone angle of the conical hole directly affect the speed of the liquid flow; the mixing chamber is also an inner conical tube component, and its cone angle is opposite to the cone angle of the nozzle. The gradually increasing structure makes the speed of the mixed flow gradually decrease, and the speed energy is converted into pressure energy with the smallest possible loss. The outer wall of the large-diameter right end of the mixing chamber is mounted on the liquid medium discharge channel of the inlet and outlet water body 15, and no flange is required here.

[0032] The jet assembly 10, i.e. the jet pump, generates power to drive the sucked medium by the liquid flow ejected from the nozzle. Therefore, the nozzle is the core component of the jet pump. The high-speed liquid flow ejected from the nozzle mouth naturally forms a low-pressure area through the suction chamber. The medium sucked into the suction chamber exchanges momentum with the high-speed liquid flow, thereby forming a uniform mixed flow that enters the mixing and expansion chamber in sequence. Figure 6 It is the jet outlet mixing and expansion chamber.

[0033] The problem to be solved by the present invention is that the existing rotary jet pump can ensure high head and small flow rate, but the mechanical efficiency may be low because the flow rate corresponding to the high efficiency range of the mechanical efficiency of the rotary jet pump is relatively large.

[0034] The present invention skillfully combines the rotary jet pump and the jet pump, which can fully expand the low-pressure end suction port of the jet assembly 10 when the flow rate is large. Figure 5 The vertical dot-dash line shown indicates that the liquid medium discharge channel has an opening at the annular channel, which guides part of the liquid medium entering the rotor cavity to flow, such as Figure 7 As shown, the liquid medium enters the low-pressure chamber of the jet assembly 10. The other part of the liquid medium enters the rotor cavity of the rotary jet pump, and like the ordinary rotary jet pump, passes through the impeller 9, the manifold nozzle, and the bottom outlet of the manifold 8, and then is ejected through the jet assembly 10, merging with the aforementioned part of the diverted liquid medium to form a relatively large flow output.

[0035] In this way, not only the shortcomings of high head and small flow of ordinary rotary jet pumps are overcome to a certain extent, the flow of the rotary jet pump is significantly improved, but also the diameter of the suction port of the suction chamber of the jet component 10 is reasonably selected, so that the rotary jet pump can work in the best mechanical efficiency range.

Claims

1. A high-efficiency rotary jet pump for outputting jet-type liquid medium, comprising a housing (11), a main shaft (4) being installed in the front end of the housing (11) through a bearing (2), a bearing end cover (1) and a bearing box (5); It is characterized in that A rotor cavity is provided in the housing (11), and the rotor cavity is composed of a rotary shell (7) and a rotary shell cover (12); an impeller (9) coaxial with the rotor cavity is fixedly installed at the rear end of the rotor cavity; the end of the main shaft (4) is connected to the front end of the rotor cavity through a driving disk (6); A cover plate (13) and an inlet and outlet water body (15) are sequentially arranged at the rear end of the housing (11); the rotary cover (12) is connected to the inlet and outlet water body (15) via a mechanical seal assembly (14); and the rotor chamber rotates relative to the housing (11) and the cover plate (13) under the drive of the main shaft (4); A stationary collecting pipe (8) is also installed in the rotor cavity. The lower end of the collecting pipe (8) is a liquid medium discharge channel. The liquid medium discharge channel is coaxially installed in the liquid medium inlet channel. A jet assembly (10) is installed on the liquid medium discharge channel. The liquid medium discharge channel has a plurality of circumferentially distributed openings at an annular channel located between the rear side of the impeller (9) and the right inner wall of the rotor chamber, which are the suction ports of the liquid medium suction chamber of the jet assembly (10).

2. A high-efficiency rotary jet pump for outputting jet-type liquid medium according to claim 1, characterized in that: A mechanical sealing component (14) is provided between the rotary shell cover (12) and the inlet and outlet water bodies (15).

3. A high-efficiency rotary jet pump for outputting jet-type liquid medium according to claim 1, characterized in that: The liquid medium entering the rotor cavity is partially distributed in the rotor cavity along the radial channel of the impeller (9) through the rotation of the impeller (9) and the rotor cavity, and obtains velocity energy, while a part of the liquid medium directly enters the suction chamber under the action of the jet assembly (10) at the bottom of the manifold (8) spraying the liquid medium in the manifold (8), thereby playing the role of diverting the rotor cavity and converging the output liquid medium.

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