Differential pressure extraction unit for venturi device and mixing device

Abstract

The utility model provides a differential pressure extraction unit for a Venturi device. The differential pressure extraction unit comprises a first pressure extraction pipe (10) and a second pressure extraction pipe (20), the first pressure extraction tube (10) has a first pressure extraction opening (11). The orientation of the first pressure extraction port (11) is set so as to be able to extract the static pressure of the main fluid. The first pressure extraction port (11) is located within a constriction tube of the venturi device. The second pressure extraction pipe (20) is provided with a second pressure extraction opening (21). The orientation of the second pressure extraction port (21) is set so as to be able to extract the total pressure or static pressure of the main fluid. The second pressure extraction port (21) is located on the rear side of the first pressure extraction port (11) in the inflow direction (L). The differential pressure extraction unit is favorable for obtaining larger main fluid differential pressure. In addition, the utility model also provides a mixing device comprising the differential pressure extraction unit.

Description

Technical Field

[0001] The utility model relates to a differential pressure extraction unit, in particular to a differential pressure extraction unit for a Venturi device and a mixing device including the differential pressure extraction unit. Background Art

[0002] A Venturi mixer utilizes the Venturi effect to mix a main fluid (such as air) and a secondary fluid (such as a combustible gas), and its performance is directly affected by the regulation ratio of the secondary fluid control valve. This regulation ratio is crucial for the Venturi mixer because it can improve energy efficiency and reduce emissions, ensure combustion efficiency under different load conditions; optimize combustion stability, provide a uniform mixture gas, and maintain an appropriate air-fuel ratio; enhance adaptability and flexibility, enabling the mixer to operate efficiently in an environment with large demand fluctuations. Therefore, a high regulation ratio is a key factor in enhancing the performance and application value of the Venturi mixer.

[0003] The regulation ratio of the secondary fluid control valve is affected by the differential pressure of the main fluid that the secondary fluid control valve can obtain. Normally, the greater the differential pressure of the main fluid, the higher the achievable regulation ratio. Currently, most Venturi mixers on the market adopt a single-point total pressure extraction mode and combine the fan speed to obtain the differential pressure of the main fluid, and it is difficult to obtain a large differential pressure of the main fluid in this way. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a differential pressure extraction unit for a Venturi device, which is conducive to obtaining a large differential pressure of the main fluid.

[0005] Another purpose of the utility model is to provide a mixing device, which is conducive to obtaining a large differential pressure of the main fluid and is conducive to improving the regulation ratio of the secondary fluid control valve.

[0006] The utility model provides a differential pressure extraction unit for a Venturi device, which includes a first pressure extraction pipe and a second pressure extraction pipe. The first pressure extraction pipe has a first pressure extraction port. The orientation of the first pressure extraction port is set to be able to extract the static pressure of the main fluid. The first pressure extraction port is located in the contraction pipe of the Venturi device. The second pressure extraction pipe has a second pressure extraction port. The orientation of the second pressure extraction port is set to be able to extract the total pressure or static pressure of the main fluid. The second pressure extraction port is located on the rear side of the first pressure extraction port along the inflow direction.

[0007] This differential pressure extraction unit for a Venturi device is conducive to obtaining a large differential pressure of the main fluid. When this differential pressure extraction unit is used in a Venturi mixer, the large differential pressure of the main fluid is conducive to improving the regulation ratio of the secondary fluid control valve.

[0008] In another schematic embodiment of the differential pressure extraction unit for a Venturi device, the first pressure extraction port is located at the small-diameter end of the converging tube of the Venturi device. Thereby, a smaller static pressure can be obtained to further increase the differential pressure of the main fluid pressure extracted by the first pressure extraction tube and the second pressure extraction tube. When this differential pressure extraction unit is used in a Venturi mixer, a larger differential pressure of the main fluid is conducive to further increasing the regulation ratio of the secondary fluid control valve.

[0009] In yet another schematic embodiment of the differential pressure extraction unit for a Venturi device, the first pressure extraction port is located on the axis of the Venturi device. Thereby, it is conducive to reducing the interference caused by fluid turbulence to pressure extraction.

[0010] In still another schematic embodiment of the differential pressure extraction unit for a Venturi device, the second pressure extraction port is located inside the inlet pipe of the Venturi device. Thereby, it is conducive to reducing the interference caused by fluid turbulence to pressure extraction.

[0011] The present utility model also provides a mixing device, which includes a Venturi mixer, a differential pressure extraction unit as described above, and a secondary fluid supply pipeline. The first pressure extraction port is located inside the converging tube of the Venturi mixer. The second pressure extraction port is located at the rear side of the first pressure extraction port along the inflow direction. The secondary fluid supply pipeline is used to supply secondary fluid to the Venturi mixer. The secondary fluid supply pipeline is provided with a secondary fluid control valve to regulate the flow rate of the secondary fluid. The actuator of the secondary fluid control valve has a first pressure sampling port and a second pressure sampling port. The first pressure sampling port is connected to the second pressure extraction tube, and the second pressure sampling port is connected to the first pressure extraction tube. The differential pressure extraction unit of this mixing device is conducive to obtaining a larger differential pressure of the main fluid, and a larger differential pressure of the main fluid is conducive to increasing the regulation ratio of the secondary fluid control valve.

[0012] In another schematic embodiment of the mixing device, the Venturi mixer includes a converging tube, a diverging tube, and an outer tube. The converging tube is axially parallel to the inflow direction and the inner diameter gradually decreases along the inflow direction. The diverging tube is coaxially arranged with the converging tube and the inner diameter of the diverging tube gradually increases along the inflow direction. The small-diameter end of the diverging tube is spaced apart and sleeved around the small-diameter end of the converging tube to form an annular secondary fluid inlet between the two. The outer tube includes a sleeve portion. The sleeve portion is coaxially arranged with the converging tube and the sleeve portion is sleeved on the converging tube and the diverging tube. The inner surface of the sleeve portion is hermetically connected to the annular edge of the large-diameter end of the converging tube and the annular edge of the large-diameter end of the diverging tube to form an annular cavity communicating with the secondary fluid inlet. A secondary fluid supply port communicating with the annular cavity is opened on the circumferential wall of the sleeve portion. The secondary fluid supply port is connected to the secondary fluid supply pipeline. The rear end of the sleeve portion along the inflow direction forms the inlet pipe of the Venturi mixer. This structure is conducive to later maintenance.

[0013] In yet another exemplary embodiment of the mixing device, the mixing device further includes two pipe connectors. The pipe connectors are inserted through and fixed to the sleeve portion. One end of the first pressure extraction pipe is connected to the portion of one pipe connector located inside the sleeve portion, and the other end is freely disposed. One end of the second pressure extraction pipe is connected to the portion of the other pipe connector located inside the sleeve portion, and the other end is freely disposed. This structure facilitates installation and subsequent maintenance.

[0014] In yet another exemplary embodiment of the mixing device, the second pressure extraction pipe includes a second extension section and a second sampling section that are continuously arranged. The second extension section is connected to the pipe connector and extends radially along the venturi mixer. The second sampling section extends axially along the venturi mixer. The second pressure extraction port is provided on the axial end face of the free end of the second sampling section. This structure facilitates the flexible setting of the position of the second pressure extraction port in the inflow direction.

[0015] In yet another exemplary embodiment of the mixing device, the first pressure extraction pipe includes a first extension section and a first sampling section that are continuously arranged. The first extension section is connected to the pipe connector and extends radially along the venturi mixer. The first sampling section extends axially along the venturi mixer. The first pressure extraction port is provided on the axial end face of the free end of the first sampling section. This structure facilitates the flexible setting of the position of the first pressure extraction port in the inflow direction.

[0016] In yet another exemplary embodiment of the mixing device, the secondary fluid supply pipeline further includes a flow limiting valve. The flow limiting valve is connected in series with the secondary fluid control valve. The mixing device further includes an inlet pressure extraction pipe provided at the inlet of the flow limiting valve and an outlet pressure extraction pipe provided at the outlet of the flow limiting valve. The actuator of the secondary fluid control valve further has a third pressure sampling port and a fourth pressure sampling port. The third pressure sampling port communicates with the inlet pressure extraction pipe, and the fourth pressure sampling port communicates with the outlet pressure extraction pipe. The provision of the flow limiting valve is conducive to improving the adjustment ability of the secondary fluid flow rate. Description of the Drawings

[0017] The following drawings only schematically illustrate and explain the present utility model and do not limit the scope of the present utility model.

[0018] Figure 1 For illustrating an exemplary embodiment of the differential pressure extraction unit for a venturi device.

[0019] Figure 2 For illustrating another exemplary embodiment of the differential pressure extraction unit for a venturi device.

[0020] Figure 3 Schematic structural diagram of an exemplary embodiment of the mixing device.

[0021] Label Description

[0022] 100 Differential pressure extraction unit

[0023] 10 First pressure extraction pipe

[0024] 11 First pressure extraction port

[0025] 12 First extension section

[0026] 13 First sampling section

[0027] 20 Second pressure extraction pipe

[0028] 21 Second pressure extraction port

[0029] 22 Second extension section

[0030] 23 Second sampling section

[0031] 200 Venturi mixer

[0032] 31 Converging pipe

[0033] 32 Diverging pipe

[0034] 33 Secondary fluid inlet

[0035] 40 Outer pipe

[0036] 41 Sleeve part

[0037] 411 Inlet pipe

[0038] 412 Secondary fluid supply port

[0039] 42 Annular cavity

[0040] 43 Interface pipe part

[0041] 50 Pipe joint

[0042] 300 Secondary fluid supply pipeline

[0043] 80 Secondary fluid control valve

[0044] 81 Actuator

[0045] 82 Valve

[0046] S1 First pressure sampling port

[0047] S2 Second pressure sampling port

[0048] S3 Third pressure sampling port

[0049] S4 Fourth pressure sampling port

[0050] 90 Flow limiting valve

[0051] 91 Inlet pressure guide pipe

[0052] 92 Outlet pressure guiding pipe

[0053] L Inflow direction

[0054] Axis A Detailed implementation manners

[0055] For a clearer understanding of the technical features, objectives, and effects of the utility model, the following describes the detailed implementation manners of the utility model with reference to the accompanying drawings. In the drawings, the same reference numerals denote components with the same or similar structures but the same functions.

[0056] In this document, "schematic" means "serving as an example, instance, or illustration", and any illustration or implementation manner described as "schematic" in this document should not be construed as a more preferred or advantageous technical solution.

[0057] In this document, "first", "second", etc. do not indicate their importance or order, etc., but are only used to indicate the differences from each other for the convenience of document description.

[0058] For the sake of simplicity of the drawings, only the parts related to the utility model are schematically shown in each drawing, and they do not represent the actual structure of the product.

[0059] Figure 1 This is used to illustrate a schematic implementation manner of a differential pressure extraction unit for a Venturi device. The Venturi device is, for example, a Venturi mixer, but is not limited thereto. In other schematic implementation manners, the Venturi device may also be other Venturi devices other than the Venturi mixer. This schematic implementation manner specifically illustrates the differential pressure extraction unit in combination with the Venturi mixer.

[0060] Such as Figure 1As shown, the Venturi mixer 200 includes, for example, a converging tube 31, a diverging tube 32, and an outer tube 40. The axis of the converging tube 31 is parallel to the inflow direction L, and the inner diameter of the converging tube 31 gradually decreases along the inflow direction L. The inflow direction L refers to the direction parallel to the axis A of the Venturi mixer 200 and from the inlet to the outlet of the Venturi mixer 200. The diverging tube 32 is coaxially arranged with the converging tube 31, and the inner diameter of the diverging tube 32 gradually increases along the inflow direction L. The small-end of the diverging tube 32 is spacedly sleeved around the small-end of the converging tube 31 to form an annular secondary fluid inlet 33 therebetween. The outer tube 40 includes a sleeve portion 41. The sleeve portion 41 is coaxially arranged with the converging tube 31, and the sleeve portion 41 is sleeved on the converging tube 31 and the diverging tube 32. The inner surface of the sleeve portion 41 is sealingly connected to the annular edge of the large-end of the converging tube 31 and the annular edge of the large-end of the diverging tube 32 to form an annular cavity 42 communicating with the secondary fluid inlet 33. A secondary fluid supply port 412 communicating with the annular cavity 42 is formed on the circumferential wall of the sleeve portion 41. The secondary fluid supply port 412 is used to communicate with the secondary fluid supply pipeline. The rear end of the sleeve portion 41 along the inflow direction L forms the inlet pipe 411 of the Venturi mixer 200.

[0061] The main fluid (such as air) first enters the Venturi mixer 200 through the inlet pipe 411, which is usually designed as a straight pipe to provide stable and uniform flow conditions. In the converging tube 31, the pipe cross-section gradually decreases, resulting in an increase in flow velocity and a decrease in static pressure. When the main fluid reaches the outlet of the converging tube 31, the flow velocity reaches the maximum and the static pressure is the lowest. At this time, the secondary fluid (such as combustible gas) added through the secondary fluid inlet 33 is mixed into the main fluid. The mixed fluid then enters the diverging tube 32, where the pipe cross-section gradually expands, the flow velocity decreases, and finally flows out of the Venturi mixer 200.

[0062] As Figure 1 As shown, the differential pressure extraction unit 100 includes a first pressure extraction pipe 10 and a second pressure extraction pipe 20. The first pressure extraction pipe 10 has a first pressure extraction port 11. The orientation of the first pressure extraction port 11 is set to be able to extract the static pressure of the main fluid. Specifically, in this exemplary embodiment, the orientation of the first pressure extraction port 11 is the same as the inflow direction L of the Venturi mixer 200, but is not limited thereto. In other exemplary embodiments, the orientation of the first pressure extraction port 11 can also be other orientations capable of extracting the static pressure of the main fluid, such as but not limited to the orientation of the first pressure extraction port 11 being perpendicular to the inflow direction L of the Venturi mixer 200.

[0063] The second pressure extraction pipe 20 has a second pressure extraction port 21. The orientation of the second pressure extraction port 21 is set to be able to extract the total pressure or static pressure of the main fluid. Specifically, in the present illustrative embodiment, the orientation of the second pressure extraction port 21 is opposite to the inflow direction L of the Venturi mixer 200 to extract the total pressure of the main fluid, but is not limited thereto. In other illustrative embodiments, the orientation of the second pressure extraction port 21 can also be other orientations capable of extracting the total pressure or static pressure of the main fluid, such as but not limited to the orientation of the second pressure extraction port 21 being the same as or perpendicular to the inflow direction L of the Venturi mixer 200.

[0064] The first pressure extraction port 11 is located in the converging pipe 31 of the Venturi mixer 200 to obtain a relatively small static pressure of the main fluid. The second pressure extraction port 21 is located on the rear side of the first pressure extraction port 11 along the inflow direction L to obtain a relatively large pressure of the main fluid. Thereby, a differential pressure of the main fluid is formed between the main fluid pressures extracted by the first pressure extraction pipe 10 and the second pressure extraction pipe 20. By configuring the positions of the first pressure extraction port 11 and the second pressure extraction port 21, a relatively large differential pressure of the main fluid can be achieved.

[0065] The differential pressure extraction unit for the Venturi device is conducive to obtaining a relatively large differential pressure of the main fluid. When the differential pressure extraction unit is used for the Venturi mixer, the relatively large differential pressure of the main fluid is conducive to improving the regulation ratio of the secondary fluid control valve.

[0066] It can be understood that the differential pressure extraction unit 100 of the present illustrative embodiment is not limited to being used for the Venturi mixer described above. Based on the same principle, it can also be used for other types / structures of Venturi mixers and can also be used for other Venturi devices other than the Venturi mixer.

[0067] As Figure 1 shown, in the illustrative embodiment, the first pressure extraction port 11 is located at the small-end of the converging pipe 31 of the Venturi mixer 200 to obtain a relatively smaller static pressure of the main fluid. Preferably, the first pressure extraction port 11 and the opening of the small-end of the converging pipe 31 of the Venturi mixer 200 are located in the same plane to minimize the obtained static pressure of the main fluid. Thereby, a relatively smaller static pressure of the main fluid can be obtained, further improving the differential pressure between the main fluid pressures extracted by the first pressure extraction pipe and the second pressure extraction pipe. When the differential pressure extraction unit is used for the Venturi mixer, the relatively larger differential pressure of the main fluid is conducive to further improving the regulation ratio of the secondary fluid control valve.

[0068] In the illustrative embodiment, the first pressure extraction port 11 is located on the axis A of the Venturi mixer 200. Thereby, it is conducive to reducing the interference caused by fluid turbulence to pressure extraction.

[0069] In a schematic embodiment, the second pressure extraction port 21 is located within the inlet pipe 411 of the Venturi mixer 200. This helps to reduce the interference caused by fluid turbulence to pressure extraction. Preferably, the second pressure extraction port 21 and the inlet of the inlet pipe 411 of the Venturi mixer 200 are in the same plane to further reduce the interference caused by fluid turbulence to pressure extraction. In other schematic embodiments, preferably, the second pressure extraction port 21 is located at the axis A of the Venturi mixer 200, which helps to further reduce the interference caused by fluid turbulence to pressure extraction.

[0070] In a schematic embodiment, the specific shapes of the first pressure extraction pipe 10 and the second pressure extraction pipe 20 can be set as needed. Figure 2 Shows a second pressure extraction pipe 20 different from that Figure 1 shown.

[0071] Figure 3 Is a schematic structural diagram of a schematic embodiment of a mixing device. As Figure 3 shown, the mixing device includes a Figure 1 shown Venturi mixer 200, a Figure 1 shown differential pressure extraction unit 100 and a secondary fluid supply pipeline 300. In other schematic embodiments, the Venturi mixer can also be the Figure 2 shown Venturi mixer.

[0072] As Figure 1 shown, the first pressure extraction port 11 is located within the contraction pipe 31 of the Venturi mixer 200 to obtain a relatively small static pressure of the main fluid. The second pressure extraction port 21 is located behind the first pressure extraction port 11 along the inflow direction L to obtain a relatively large pressure of the main fluid. This forms a differential pressure of the main fluid between the main fluid pressures extracted by the first pressure extraction pipe 10 and the second pressure extraction pipe 20. By configuring the positions of the first pressure extraction port 11 and the second pressure extraction port 21, a relatively large differential pressure of the main fluid can be achieved.

[0073] The secondary fluid supply pipeline 300 is used to supply the secondary fluid to the Venturi mixer 200. As Figure 3As shown, a secondary fluid supply pipeline 300 is provided with a secondary fluid control valve 80 to regulate the flow rate of the secondary fluid. The actuator 81 of the secondary fluid control valve 80 has a first pressure sampling port S1 and a second pressure sampling port S2. The first pressure sampling port S1 is communicated with the second pressure extraction pipe 20 through a hose (not shown in the figure), and the second pressure sampling port S2 is communicated with the first pressure extraction pipe 10 through a hose (not shown in the figure). In use, for example, the actuator 81 can be set to adjust the opening degree of the valve 82 of the secondary fluid control valve 80 according to the differential pressure of the fluid pressure collected from the first pressure sampling port S1 and the second pressure sampling port S2, so as to automatically control the flow rate of the secondary fluid according to the flow rate of the main fluid.

[0074] The differential pressure extraction unit of the mixing device is conducive to obtaining a larger differential pressure of the main fluid, and the larger differential pressure of the main fluid is conducive to improving the regulation ratio of the secondary fluid control valve.

[0075] As Figure 1 shown, in the schematic embodiment, the Venturi mixer 200 includes a contraction pipe 31, a diffuser pipe 32 and an outer pipe 40. The contraction pipe 31 is axially parallel to the inflow direction L and the inner diameter gradually decreases along the inflow direction L, where the inflow direction L refers to the direction parallel to the axis of the Venturi mixer 200 from the inlet of the Venturi mixer 200 to the outlet of the Venturi mixer 200. The diffuser pipe 32 is coaxially arranged with the contraction pipe 31 and the inner diameter of the diffuser pipe 32 gradually increases along the inflow direction L. The small end of the diffuser pipe 32 is sleeved around the small end of the contraction pipe 31 at intervals to form an annular secondary fluid inlet 33 therebetween.

[0076] The outer pipe 40 includes a sleeve portion 41. The sleeve portion 41 is coaxially arranged with the contraction pipe 31 and the sleeve portion 41 is sleeved on the contraction pipe 31 and the diffuser pipe 32. The inner surface of the sleeve portion 41 is hermetically connected to the annular edge of the large end of the contraction pipe 31 and the annular edge of the large end of the diffuser pipe 32 to form an annular cavity 42 communicating with the secondary fluid inlet 33. A secondary fluid supply port 412 communicating with the annular cavity 42 is opened on the circumferential wall of the sleeve portion 41. The secondary fluid supply port 412 communicates with the secondary fluid supply pipeline 300. Specifically, as Figure 1 and Figure 3 shown, the outer pipe 40 further includes an interface pipe portion 43. The interface pipe portion 43 is tubular and one end communicates with the secondary fluid supply port 412, and the other end is used to connect the supply pipeline 300. The rear end of the sleeve portion 41 along the inflow direction L forms the inlet pipe 411 of the Venturi mixer 200. Flange plates for connecting external pipelines are provided at both ends of the sleeve portion 41. This structure is conducive to later maintenance.

[0077] The main fluid (such as air) first enters the Venturi mixer 200 through the inlet pipe 411, which is usually designed as a straight pipe to provide stable and uniform flow conditions. In the converging pipe 31, the cross-section of the pipe gradually decreases, resulting in an increase in flow velocity and a decrease in static pressure. When the main fluid reaches the outlet of the converging pipe 31, the flow velocity reaches the maximum and the static pressure reaches the minimum. At this time, the secondary fluid (such as combustible gas) added through the secondary fluid inlet 33 is mixed into the main fluid. The mixed fluid then enters the diverging pipe 32, where the cross-section of the pipe gradually expands, the flow velocity decreases, and finally flows out of the Venturi mixer 200.

[0078] As Figure 1 shown, in the schematic embodiment, the mixing device further includes two pipe connectors 50. The pipe connectors 50 penetrate and are fixed to the sleeve portion 41. One end of the first pressure extraction pipe 10 is connected to the portion of one pipe connector 50 located inside the sleeve portion 41, and the other end is freely disposed. One end of the second pressure extraction pipe 20 is connected to the portion of the other pipe connector 50 located inside the sleeve portion 41, and the other end is freely disposed. This structure facilitates installation and subsequent maintenance.

[0079] As Figure 1 shown, in the schematic embodiment, the second pressure extraction pipe 20 includes a second extension section 22 and a second sampling section 23 that are continuously arranged. The second extension section 22 is connected to the pipe connector 50 and extends radially along the Venturi mixer 200. The second sampling section 23 extends axially along the Venturi mixer 200. The second pressure extraction port 21 is provided on the axial end face of the free end of the second sampling section 23. This structure facilitates the flexible setting of the position of the second pressure extraction port 21 along the inflow direction L.

[0080] As Figure 2 shown, in other schematic embodiments, the second pressure extraction pipe 20 can also be set as a straight pipe extending radially along the Venturi mixer 200 and the axial end face of its free end is closed. The second pressure extraction port 21 is opened, for example, on the circumferential wall of the second pressure extraction pipe 20.

[0081] As Figure 1 shown, in the present schematic embodiment, the first pressure extraction pipe 10 includes a first extension section 12 and a first sampling section 13 that are continuously arranged. The first extension section 12 is connected to the pipe connector 50 and extends radially along the Venturi mixer 200. The first sampling section 13 extends axially along the Venturi mixer 200. The first pressure extraction port 11 is provided on the axial end face of the free end of the first sampling section 13. This structure facilitates the flexible setting of the position of the first pressure extraction port 11 along the inflow direction L.

[0082] As Figure 3As shown, in the illustrative embodiment, the secondary fluid supply line 300 further includes a flow limiting valve 90. The flow limiting valve 90 is connected in series with the secondary fluid control valve 80. The mixing device further includes an inlet pressure tapping pipe 91 disposed at the inlet of the flow limiting valve 90 and an outlet pressure tapping pipe 92 disposed at the outlet of the flow limiting valve 90. The inlet pressure tapping pipe 91 is used, for example, to extract the static pressure of the fluid at the inlet of the flow limiting valve 90, and the outlet pressure tapping pipe 92 is used, for example, to extract the static pressure of the fluid at the outlet of the flow limiting valve 90.

[0083] The actuator 81 of the secondary fluid control valve 80 further has a third pressure sampling port S3 and a fourth pressure sampling port S4. The third pressure sampling port S3 is connected to the inlet pressure tapping pipe 91 through a hose (not shown in the figure), and the fourth pressure sampling port S4 is connected to the outlet pressure tapping pipe 92 through a hose (not shown in the figure). In use, for example, the actuator 81 can be set to adjust the opening degree of the valve 82 of the secondary fluid control valve 80 according to the differential pressure of the fluid pressure collected from the third pressure sampling port S3 and the fourth pressure sampling port S4, so as to be able to automatically make an adaptive adjustment according to the change of the opening degree of the flow limiting valve 90. In use, the control valve 80 is used, for example, for small-scale adjustment and real-time adjustment of the secondary fluid flow rate, and the flow limiting valve 90 is used, for example, for large-scale adjustment and pre-adjustment of the secondary fluid flow rate. The setting of the flow limiting valve is beneficial to improving the adjustment ability of the secondary fluid flow rate.

[0084] It should be understood that although this specification is described according to each embodiment, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0085] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalent implementation or change made without departing from the technical spirit of the present invention, such as the combination, division or repetition of features, shall be included in the protection scope of the present invention.

Claims

1. A differential pressure extraction unit for a Venturi device, characterized in that: include: A first pressure extraction pipe (10) having a first pressure extraction port (11), wherein the first pressure extraction port (11) is oriented so as to be able to extract the static pressure of the main fluid, and the first pressure extraction port (11) is located in the contraction tube of the venturi device; as well as A second pressure extraction pipe (20) has a second pressure extraction port (21), the direction of the second pressure extraction port (21) is set to be able to extract the total pressure or static pressure of the main fluid, and the second pressure extraction port (21) is located on the rear side of the first pressure extraction port (11) along the inlet direction (L).

2. The differential pressure extraction unit for a Venturi device according to claim 1, characterized in that: The first pressure extraction port (11) is located at the small end of the contraction tube of the venturi device.

3. The differential pressure extraction unit for a Venturi device according to claim 1, characterized in that: The first pressure extraction port (11) is located at the axis (A) of the Venturi device.

4. The differential pressure extraction unit for a Venturi device according to claim 1, characterized in that: The second pressure extraction port (21) is located in the inlet pipe of the Venturi device.

5. A mixing device, characterized in that include: a venturi mixer (200); A differential pressure extraction unit according to any one of claims 1 to 4, wherein the first pressure extraction port (11) is located in the contraction tube of the Venturi mixer (200), and the second pressure extraction port (21) is located at the rear side of the first pressure extraction port (11) along the inlet direction (L); as well as A secondary fluid supply pipeline (300) is used to provide secondary fluid to the Venturi mixer (200). The secondary fluid supply pipeline (300) is provided with a secondary fluid control valve (80) to adjust the flow rate of the secondary fluid. The actuator (81) of the secondary fluid control valve (80) has a first pressure sampling port (S1) and a second pressure sampling port (S2). The first pressure sampling port (S1) is connected to the second pressure extraction pipe (20), and the second pressure sampling port (S2) is connected to the first pressure extraction pipe (10).

6. The mixing device according to claim 5, characterized in that The venturi mixer (200) comprises: A shrink tube (31) whose axial direction is parallel to the inflow direction (L) and whose inner diameter gradually decreases along the inflow direction (L); a diffuser (32) which is coaxially arranged with the contraction tube (31) and whose inner diameter gradually increases along the inflow direction (L); the small-mouth end of the diffuser (32) is intermittently sleeved on the small-mouth end of the contraction tube (31) to form an annular secondary fluid inlet (33) therebetween; and An outer tube (40) comprises a sleeve portion (41), wherein the sleeve portion (41) is coaxially arranged with the shrink tube (31) and sleeved on the shrink tube (31) and the diffuser (32), wherein the inner surface of the sleeve portion (41) is sealedly connected to the annular edge of the large end of the shrink tube (31) and the annular edge of the large end of the diffuser (32) to form an annular cavity (42) connected to the secondary fluid inlet (33), and a secondary fluid supply port (412) connected to the annular cavity (42) is provided on the circumferential wall of the sleeve portion (41), wherein the secondary fluid supply port (412) is connected to the secondary fluid supply pipeline (300), and the rear end of the sleeve portion (41) along the inlet direction (L) forms the inlet pipe (411) of the Venturi mixer (200).

7. The mixing device according to claim 6, characterized in that The mixing device further comprises two pipe joints (50), wherein the pipe joints (50) are passed through and fixed to the sleeve portion (41), one end of the first pressure extraction pipe (10) is connected to a portion of one pipe joint (50) located inside the sleeve portion (41), and the other end is freely arranged, and one end of the second pressure extraction pipe (20) is connected to a portion of another pipe joint (50) located inside the sleeve portion (41), and the other end is freely arranged.

8. The mixing device according to claim 7, characterized in that The second pressure extraction tube (20) comprises a second extension section (22) and a second sampling section (23) which are arranged in series, the second extension section (22) being connected to the pipe joint (50) and extending in the radial direction of the Venturi mixer (200), the second sampling section (23) extending in the axial direction of the Venturi mixer (200), and the second pressure extraction port (21) being arranged on the axial end face of the free end of the second sampling section (23).

9. The mixing device according to claim 7, characterized in that The first pressure extraction tube (10) comprises a first extension section (12) and a first sampling section (13) which are arranged continuously, wherein the first extension section (12) is connected to the pipe joint (50) and extends in the radial direction of the Venturi mixer (200), the first sampling section (13) extends in the axial direction of the Venturi mixer (200), and the first pressure extraction port (11) is arranged on the axial end face of the free end of the first sampling section (13).

10. The mixing device according to claim 5, characterized in that The secondary fluid supply pipeline (300) further comprises a flow limiting valve (90), wherein the flow limiting valve (90) is connected in series with the secondary fluid control valve (80), and the mixing device further comprises an inlet pressure-conducting pipe (91) arranged at the inlet of the flow limiting valve (90) and an outlet pressure-conducting pipe (92) arranged at the outlet of the flow limiting valve (90). The actuator (81) of the secondary fluid control valve (80) further comprises a third pressure sampling port (S3) and a fourth pressure sampling port (S4), wherein the third pressure sampling port (S3) is connected to the inlet pressure-conducting pipe (91), and the fourth pressure sampling port (S4) is connected to the outlet pressure-conducting pipe (92).

Images