Multi-point backrest type flow tube

Abstract

The utility model provides a kind of multi-point backrest type velocity tube, comprising: multiple velocity probes, positive pressure connecting pipe and negative pressure connecting pipe, each velocity probe includes: positive pressure measuring pipe and negative pressure measuring pipe fixedly arranged back to back;The positive pressure measuring pipe and negative pressure measuring pipe are hollow pipe;The first end of the positive pressure measuring pipe and negative pressure measuring pipe is inclined plane hole;The positive pressure measuring pipe of each velocity probe is sequentially arranged in head and tail, the negative pressure measuring pipe of each velocity probe is sequentially arranged in head and tail;The tail end of two adjacent positive pressure measuring pipes is communicated via the positive pressure connecting pipe being arranged between the two, the tail end of two adjacent negative pressure measuring pipes is communicated via the negative pressure connecting pipe being arranged between the two.The multi-point backrest type velocity tube provided by the utility model is simple and reliable in structure, and can improve the efficiency of measuring the wind speed of wind powder pipeline.

Description

Technical Field

[0001] This utility model relates to the field of speed measuring tube technology, specifically to a multi-point backrest speed measuring tube. Background Technology

[0002] In the performance testing and daily monitoring of pulverizing systems in coal-fired power plants, wind speed is one of the most basic and critical measurement objects. The fluid in the outlet air-coal duct of the pulverizing system is a gas-solid two-phase flow. The BS-I type back-mounted tube is a non-standard velocity measuring tube recommended by power industry standards for directly measuring the velocity of the gas-solid two-phase flow in the air-coal duct. Figure 1 As shown, when using the BS-I type back-mounted tube to measure the flow velocity of dust-laden airflow, it is less prone to dust accumulation and does not require correction for coal dust mass concentration.

[0003] For air-powder ducts, if the upstream straight section of the wind speed measuring point is ≥10D (D is the equivalent diameter of the measured duct), the downstream straight section is ≥3D, and there are no local resistance elements such as dampers or baffles, only one measuring hole needs to be opened, and the measurement method of a pre-calibrated representative point can be used. If the above straight section conditions are not met, 2 to 3 measuring holes should be opened (evenly distributed along the circumference), that is, multiple wind speed measuring points should be set.

[0004] Due to site constraints, the straight sections before and after the wind speed measurement points in air-powder ducts often fail to meet the aforementioned straight section requirements, resulting in multiple wind speed measurement points. Therefore, measuring the wind speed in air-powder ducts requires inserting a backing pipe into the duct, adjusting its position, and measuring each point individually using the cross-sectional grid method, then calculating the average value. This method is labor-intensive, time-consuming, prone to significant human error, and has low measurement accuracy. Utility Model Content

[0005] To address at least one problem in the prior art, this utility model provides a multi-point back-to-back speed measuring tube, which has a simple and reliable structure and can improve the efficiency of measuring wind speed in air-powder pipelines.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0007] This utility model provides a multi-point back-to-back speed measuring tube, including: multiple speed measuring probes, a positive pressure connecting tube and a negative pressure connecting tube, each speed measuring probe including: a positive pressure measuring tube and a negative pressure measuring tube fixedly arranged back to back;

[0008] Both the positive pressure measuring tube and the negative pressure measuring tube are hollow pipes; the beginning ends of both the positive pressure measuring tube and the negative pressure measuring tube are beveled holes; the positive pressure measuring tubes in each speed probe are arranged end to end in sequence, and the negative pressure measuring tubes in each speed probe are arranged end to end in sequence.

[0009] The ends of two adjacent positive pressure measuring tubes are connected via a positive pressure connecting tube disposed between them, and the ends of two adjacent negative pressure measuring tubes are connected via a negative pressure connecting tube disposed between them.

[0010] In one embodiment, both the positive pressure connecting pipe and the negative pressure connecting pipe are U-shaped pipes;

[0011] The positive pressure connecting pipe and the negative pressure connecting pipe between two adjacent speed measuring probes form a rectangular space, and the vertical planes corresponding to the inclined holes of the positive pressure measuring pipe and the negative pressure measuring pipe are perpendicular to the rectangular space.

[0012] In one embodiment, the beveled hole of the positive pressure measuring tube is used to face the direction of airflow, and the beveled hole of the negative pressure measuring tube is used to face away from the direction of airflow.

[0013] In one embodiment, the axes of all positive pressure measuring tubes are on the same straight line, and the axes of all negative pressure measuring tubes are on the same straight line.

[0014] In one embodiment, the multi-point back-to-back speed measuring tube further includes: a positive pressure lead-out tube and a negative pressure lead-out tube;

[0015] The outlet of the positive pressure measuring tube at the tail position is connected to the positive pressure lead-out tube, and the outlet of the negative pressure measuring tube at the tail position is connected to the negative pressure lead-out tube.

[0016] In one embodiment, both the positive pressure lead and the negative pressure lead are used to connect to a micromanometer.

[0017] In one embodiment, the angle between the inclined plane corresponding to the inclined hole and the vertical plane is 75°.

[0018] In one embodiment, the positive pressure measuring tube, the negative pressure measuring tube, the positive pressure connecting tube, and the negative pressure connecting tube are all stainless steel pipes.

[0019] In one embodiment, the positive pressure lead-out tube includes: a straight tube and a bent tube communicating with the straight tube, the straight tube of the positive pressure lead-out tube being connected to the tail end of a positive pressure measuring tube at the tail position, and the bent tube of the positive pressure lead-out tube being used to connect to a micromanometer; the negative pressure lead-out tube includes: a straight tube and a bent tube communicating with the straight tube, the straight tube of the negative pressure lead-out tube being connected to the tail end of a negative pressure measuring tube at the tail position, and the bent tube of the negative pressure lead-out tube being used to connect to a micromanometer.

[0020] In one embodiment, the positive pressure connecting pipes and negative pressure connecting pipes have the same structure.

[0021] As can be seen from the above technical solution, this utility model provides a multi-point back-to-back speed measuring tube, including: multiple speed measuring probes, a positive pressure connecting pipe, and a negative pressure connecting pipe. Each speed measuring probe includes: a positive pressure measuring pipe and a negative pressure measuring pipe fixed back-to-back; both the positive pressure measuring pipe and the negative pressure measuring pipe are hollow pipes; the beginning ends of both the positive pressure measuring pipe and the negative pressure measuring pipe are beveled holes; the positive pressure measuring pipes in each speed measuring probe are arranged end-to-end in sequence, and the negative pressure measuring pipes in each speed measuring probe are arranged end-to-end in sequence; the end ends of two adjacent positive pressure measuring pipes are connected through a positive pressure connecting pipe disposed between them, and the end ends of two adjacent negative pressure measuring pipes are connected through a negative pressure connecting pipe disposed between them. This multi-point back-to-back... The velocity measuring tube has a simple and reliable structure, which can improve the efficiency of measuring the wind speed in air-powder ducts. The multi-point back-to-back velocity measuring tube can be inserted into the air-powder duct, and the wind speed measuring points corresponding to each velocity measuring probe can be different, so that multiple wind speed measuring points can be measured simultaneously. While ensuring the accuracy of wind speed measurement in air-powder ducts, it improves the efficiency of measuring the wind speed of the entire cross-section of the air-powder duct. That is, by placing multiple velocity measuring probes in appropriate positions and connecting them in series, the wind speed of the entire cross-section of the air-powder duct can be measured simply and quickly. Moreover, it is not easy to accumulate dust when measuring the flow velocity of dusty airflow, and there is no need to perform coal dust mass concentration correction. Its measurement workload is small, the measurement time is short, the human error is small, and the measurement accuracy is high.

[0022] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the BS-I type backrest tube in the prior art.

[0025] Figure 2 This is a schematic diagram of the structure of the multi-point backrest speed measuring tube in an embodiment of this utility model.

[0026] Figure 3 This is a top view schematic diagram of the multi-point backrest speed measuring tube in the embodiment of this utility model.

[0027] Figure 4 This is a schematic diagram showing the relationship between the speed measuring probe, the positive pressure connecting pipe, and the negative pressure connecting pipe in an embodiment of this utility model.

[0028] Figure 5This is a side view of the positive pressure measuring tube and the negative pressure measuring tube in the embodiments of this utility model.

[0029] Figure 6 This is a schematic diagram of the structure of a multi-point backrest speed measuring tube in another embodiment of the present invention.

[0030] Figure 7 This is a top view schematic diagram of the multi-point backrest speed measuring tube in another embodiment of the present invention.

[0031] Icon labels:

[0032] 1. Speed ​​measuring probe;

[0033] 11. Positive pressure measuring tube;

[0034] 12. Negative pressure measuring tube;

[0035] 21. Positive pressure connecting pipe;

[0036] 22. Negative pressure connecting pipe;

[0037] 31. Positive pressure measuring port;

[0038] 32. Negative pressure measuring port;

[0039] 41. Positive pressure outlet pipe;

[0040] 42. Negative pressure outlet pipe;

[0041] 51. Vertical plane;

[0042] 52. Incline;

[0043] 61. The axis of the positive pressure measuring tube;

[0044] 62. The axis of the negative pressure measuring tube. Detailed Implementation

[0045] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0046] Specific embodiments of the present invention are disclosed in detail with reference to the following description and accompanying drawings, indicating how the principles of the present invention can be employed. It should be understood that the embodiments of the present invention are not limited in scope. Within the spirit and scope of the appended claims, the embodiments of the present invention include many changes, modifications, and equivalents.

[0047] Features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0048] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, or components.

[0049] This utility model provides an example of a multi-point back-mounted velocity measuring tube, which has a simple and reliable structure and can improve the efficiency of measuring wind speed in air-powder ducts. See [link to relevant documentation]. Figures 2 to 4 The multi-point back-mounted speed measuring tube includes:

[0050] The system includes multiple speed measuring probes 1, a positive pressure connecting pipe 21, and a negative pressure connecting pipe 22. Each speed measuring probe 1 includes a positive pressure measuring pipe 11 and a negative pressure measuring pipe 12 fixed back to back. Both the positive pressure measuring pipe 11 and the negative pressure measuring pipe 12 are hollow pipes. The beginning ends of both the positive pressure measuring pipe 11 and the negative pressure measuring pipe 12 are beveled holes. The positive pressure measuring pipes 11 in each speed measuring probe 1 are arranged end to end in sequence, and the negative pressure measuring pipes 12 in each speed measuring probe 1 are arranged end to end in sequence. The end ends of two adjacent positive pressure measuring pipes 11 are connected through the positive pressure connecting pipe 21 between them, and the end ends of two adjacent negative pressure measuring pipes 12 are connected through the negative pressure connecting pipe 22 between them.

[0051] Specifically, the positive pressure measuring tube 11 and the negative pressure measuring tube 12 in the same speed probe 1 can be welded together back to back. Both the positive pressure measuring tube 11 and the negative pressure measuring tube 12 can be hollow straight pipes. The beveled hole of the positive pressure measuring tube 11 is the positive pressure measuring hole 31, and the beveled hole of the negative pressure measuring tube 12 is the negative pressure measuring hole 32. In this embodiment, the beveled hole of the positive pressure measuring tube 11 in the first speed probe 1 can be connected to the outlet of the positive pressure measuring tube 11 in the last speed probe 1. The beveled hole of the negative pressure measuring tube 12 in the first speed probe 1 can be connected to the outlet of the negative pressure measuring tube 12 in the last speed probe 1. The outlets of both the positive pressure measuring tube 11 and the negative pressure measuring tube 12 in the last speed probe 1 can be connected to a micromanometer.

[0052] Each positive pressure measuring tube 11 may have an outlet at its tail end. The first positive pressure measuring tube 11 has one outlet, which is used to connect to the positive pressure connecting tube 21. The last positive pressure measuring tube 11 has two outlets, one on the side wall of the tail end, which is used to connect to the positive pressure connecting tube 21, and the other at the bottom of the tail end, which can be used to connect to the micromanometer. The other positive pressure measuring tubes 11 may have two outlets, which are symmetrically opened on the side wall of the tail end of the positive pressure measuring tube 11, and the two outlets are respectively connected to their corresponding positive pressure connecting tubes 21. The first negative pressure measuring tube 12 has one outlet for connecting to the negative pressure connecting tube 22; the last negative pressure measuring tube 12 has two outlets, one on the side wall of the last end for connecting to the negative pressure connecting tube 22, and the other at the bottom of the last end for connecting to a micromanometer; the remaining negative pressure measuring tubes 12 each have two outlets, symmetrically located on the side wall of the last end of the negative pressure measuring tube 12, and the two outlets are connected to their respective negative pressure connecting tubes 22.

[0053] To improve the reliability of the multi-point back-to-back speed measuring tube, the positive pressure measuring tube 11, negative pressure measuring tube 12, positive pressure connecting tube 21, and negative pressure connecting tube 22 can all be made of stainless steel pipes. Preferably, all of these are Φ10×1 stainless steel pipes. The structures of each positive pressure connecting tube 21 and negative pressure connecting tube 22 can be identical.

[0054] Specifically, the angled hole of the positive pressure measuring tube 11 can be used to face the direction of airflow, that is, to be located on the windward side; the angled hole of the negative pressure measuring tube 12 can be used to face away from the direction of airflow, that is, to be located on the leeward side. Figure 5 In the diagram, 61 represents the axis of the positive pressure measuring tube 11, 62 represents the axis of the negative pressure measuring tube 12, 51 represents the vertical plane, and 52 represents the inclined plane. Figure 5 As shown, the airflow direction can be parallel to the vertical plane 51 corresponding to the inclined hole, and the inclined plane 52 forms an angle with the vertical plane 51. Preferably, the angle between the inclined plane corresponding to the inclined hole and the vertical plane is 75°. The axes of each positive pressure measuring tube 11 can be on the same straight line, and the axes of each negative pressure measuring tube 12 can be on the same straight line. The multi-point back-to-back velocity measuring tube provided in this embodiment can be a multi-point BS-I type back-to-back tube, which can be a wind speed measuring device for the outlet air-coal duct of the pulverizing system of a coal-fired power plant. Except for the outlet and outlet position, the structures of each velocity measuring probe in this embodiment can be the same, and can be consistent with the velocity measuring probe of the existing BS-I type back-to-back tube.

[0055] As described above, the multi-point back-to-back speed measuring tube provided in this embodiment has a simple and reliable structure, which can improve the efficiency of measuring the wind speed in air-powder ducts. The number and relative positions of the speed measuring probes can be determined according to the dimensions of the air-powder duct using methods in the standard, and then a multi-point back-to-back speed measuring tube suitable for that duct size can be custom-made. The multi-point back-to-back speed measuring tube is inserted into the air-powder duct, and the tail end of the tube can be connected to a micromanometer via a flexible hose to measure the wind speed across the entire cross-section of the air-powder duct.

[0056] To ensure that the positive pressure connecting pipe and the negative pressure connecting pipe do not obstruct the speed measuring probe and that the speed measuring probe can measure the pressure of the air-powder pipeline normally, in one embodiment, both the positive pressure connecting pipe 21 and the negative pressure connecting pipe 22 are U-shaped pipes; the positive pressure connecting pipe 21 and the negative pressure connecting pipe 22 between two adjacent speed measuring probes form a rectangular space, and the vertical planes corresponding to the inclined holes of the positive pressure measuring pipe 11 and the negative pressure measuring pipe 12 are perpendicular to the rectangular space.

[0057] To facilitate the extraction of pressure from the air-powder duct, such as Figure 6 and Figure 7 As shown, in one embodiment, the multi-point backrest speed measuring tube further includes: a positive pressure lead-out tube 41 and a negative pressure lead-out tube 42; the outlet of the positive pressure measuring tube 11 at the tail position is connected to the positive pressure lead-out tube 41, and the outlet of the negative pressure measuring tube 12 at the tail position is connected to the negative pressure lead-out tube 42.

[0058] Specifically, both the positive pressure outlet pipe 41 and the negative pressure outlet pipe 42 are used to connect to a micromanometer. The positive pressure outlet pipe 41 and the negative pressure outlet pipe 42 can have the same structure and can both be metal pipes. Preferably, both the positive pressure outlet pipe 41 and the negative pressure outlet pipe 42 are Φ10×1 stainless steel pipes. The positive pressure outlet pipe 41 includes a straight pipe and a bent pipe connected to the straight pipe. The straight pipe of the positive pressure outlet pipe 41 is connected to the tail end of the positive pressure measuring pipe 11, and the bent pipe of the positive pressure outlet pipe 41 is used to connect to the micromanometer. The negative pressure outlet pipe 42 includes a straight pipe and a bent pipe connected to the straight pipe. The straight pipe of the negative pressure outlet pipe 42 is connected to the tail end of the negative pressure measuring pipe 12, and the bent pipe of the negative pressure outlet pipe 42 is used to connect to the micromanometer. A U-shaped space can be formed between the positive pressure outlet pipe 41 and the bent pipe of the negative pressure outlet pipe 42.

[0059] Based on the above, this utility model also provides an application example of a multi-point back-to-back speed measuring tube. In this application example, the multi-point back-to-back speed measuring tube includes: multiple speed measuring probes, connecting pipes, and lead-out pipes. Specifically:

[0060] (1) Speed ​​probe

[0061] The speed measuring probe consists of a positive pressure measuring tube and a negative pressure measuring tube. Both the positive and negative pressure measuring tubes are hollow pipes.

[0062] The first end of the positive pressure measuring tube is a positive pressure measuring hole, which is an inclined hole with an angle of 75° between the inclined plane and the vertical plane. The second end of the positive pressure measuring tube is a blind tube. The side of the second end of the positive pressure measuring tube is connected to the positive pressure connecting pipe, and the positive pressure measuring tube and the positive pressure connecting pipe are internally connected. Airflow can enter the positive pressure connecting pipe through the positive pressure measuring hole and the positive pressure measuring tube. Multiple positive pressure measuring tubes are connected together by multiple positive pressure connecting pipes. The positive pressure measuring tube of the last velocity probe is connected to the positive pressure outlet pipe. The air-powder pipeline pressure measured by the multiple positive pressure measuring holes is then led out by the positive pressure outlet pipe.

[0063] The first end of the negative pressure measuring tube is a negative pressure measuring hole, which is an inclined hole with an angle of 75° between the inclined plane and the vertical plane. The second end of the negative pressure measuring tube is a blind tube. The side of the second end of the negative pressure measuring tube is connected to the negative pressure connecting pipe, and the interiors of the negative pressure measuring tube and the negative pressure connecting pipe are interconnected. Airflow can enter the negative pressure connecting pipe through the negative pressure measuring hole and the negative pressure measuring tube. Multiple negative pressure measuring tubes are connected together by multiple negative pressure connecting pipes. The negative pressure measuring tube of the last speed measuring probe is connected to the negative pressure outlet pipe. The air-powder pipeline pressure measured by the multiple negative pressure measuring holes is then led out by the negative pressure outlet pipe.

[0064] Both the positive and negative pressure measuring tubes are made of metal and can be welded back-to-back to form a speed measuring probe. The positive and negative pressure measuring tubes are made of Φ10×1 stainless steel.

[0065] The multi-point back-to-back speed measuring tube in this application example has multiple speed measuring probes. The number and relative positions of the speed measuring probes can be determined according to the size of the air-powder duct and the method in the standard.

[0066] (2) Connecting pipe

[0067] The connecting pipes are hollow tubes that connect the various speed measuring probes. There are two types of connecting pipes: positive pressure connecting pipes and negative pressure connecting pipes. The positive pressure connecting pipes are U-shaped, connecting multiple positive pressure measuring tubes together from the side. The negative pressure connecting pipes are U-shaped, connecting multiple negative pressure measuring tubes together from the side. Both positive and negative pressure connecting pipes are made of Φ10×1 stainless steel. The positive and negative pressure connecting pipes do not obstruct the speed measuring probes, allowing them to measure the pressure in the air-powder duct normally.

[0068] The positive and negative pressure connecting pipes form several rectangular spaces, within which some speed measuring probes are located. The positive and negative pressure connecting pipes do not obstruct the speed measuring probes, allowing them to measure the pressure in the air-powder duct normally.

[0069] (3) Outlet tube

[0070] The outlet pipes are divided into positive pressure outlet pipes and negative pressure outlet pipes. Both the positive and negative pressure outlet pipes have a ferrule at the end for easy connection to a flexible hose. They can be connected to a micromanometer via a flexible hose to measure the pressure in the air-powder pipeline. Both the positive and negative pressure outlet pipes are made of Φ10×1 stainless steel.

[0071] As described above, the multi-point back-to-back speed measuring tube provided by this utility model has a simple and reliable structure, which can improve the efficiency of measuring the wind speed of the air-powder pipeline; each speed measuring probe corresponds to a different wind speed measuring point, and multiple wind speed measuring points can be measured simultaneously. While ensuring the accuracy of the wind speed measurement in the air-powder pipeline, it improves the efficiency of measuring the wind speed of the entire cross section of the air-powder pipeline; it is not easy to accumulate dust when measuring the flow velocity of dusty airflow, and there is no need to perform coal powder mass concentration correction. Its measurement workload is small, the measurement time is short, the human error is small, and the measurement accuracy is high.

[0072] This utility model uses specific embodiments to illustrate the principle and implementation of the utility model. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​the utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the utility model. Therefore, the content of this specification should not be construed as a limitation of the utility model.

Claims

1. A multi-point backrest speed measuring tube, characterized in that, include: Multiple speed measuring probes, positive pressure connecting pipes and negative pressure connecting pipes, each speed measuring probe including: a positive pressure measuring pipe and a negative pressure measuring pipe fixed back to back; Both the positive pressure measuring tube and the negative pressure measuring tube are hollow pipes; the beginning ends of both the positive pressure measuring tube and the negative pressure measuring tube are beveled holes; the positive pressure measuring tubes in each speed probe are arranged end to end in sequence, and the negative pressure measuring tubes in each speed probe are arranged end to end in sequence. The ends of two adjacent positive pressure measuring tubes are connected via a positive pressure connecting tube disposed between them, and the ends of two adjacent negative pressure measuring tubes are connected via a negative pressure connecting tube disposed between them.

2. The multi-point backrest speed measuring tube according to claim 1, characterized in that, Both the positive pressure connecting pipe and the negative pressure connecting pipe are U-shaped pipes; The positive pressure connecting pipe and the negative pressure connecting pipe between two adjacent speed measuring probes form a rectangular space, and the vertical planes corresponding to the inclined holes of the positive pressure measuring pipe and the negative pressure measuring pipe are perpendicular to the rectangular space.

3. The multi-point backrest speed measuring tube according to claim 1, characterized in that, The angled holes of the positive pressure measuring tube are for facing the direction of airflow, while the angled holes of the negative pressure measuring tube are for facing away from the direction of airflow.

4. The multi-point backrest speed measuring tube according to claim 1, characterized in that, The axes of all positive pressure measuring tubes are on the same straight line, and the axes of all negative pressure measuring tubes are on the same straight line.

5. The multi-point backrest speed measuring tube according to claim 1, characterized in that, Also includes: Positive pressure outlet pipe and negative pressure outlet pipe; The outlet of the positive pressure measuring tube at the tail position is connected to the positive pressure lead-out tube, and the outlet of the negative pressure measuring tube at the tail position is connected to the negative pressure lead-out tube.

6. The multi-point backrest speed measuring tube according to claim 5, characterized in that, Both the positive pressure lead-out tube and the negative pressure lead-out tube are used to connect to the micromanometer.

7. The multi-point backrest speed measuring tube according to claim 1, characterized in that, The angle between the inclined plane corresponding to the inclined hole and the vertical plane is 75°.

8. The multi-point backrest speed measuring tube according to claim 1, characterized in that, The positive pressure measuring tube, negative pressure measuring tube, positive pressure connecting tube, and negative pressure connecting tube are all stainless steel pipes.

9. The multi-point backrest speed measuring tube according to claim 5, characterized in that, The positive pressure lead-out tube includes a straight tube and a bent tube connected to the straight tube. The straight tube of the positive pressure lead-out tube is connected to the tail end of the positive pressure measuring tube at the tail position, and the bent tube of the positive pressure lead-out tube is used to connect to a micromanometer. The negative pressure lead-out tube includes a straight tube and a bent tube connected to the straight tube. The straight tube of the negative pressure lead-out tube is connected to the tail end of the negative pressure measuring tube at the tail position, and the bent tube of the negative pressure lead-out tube is used to connect to a micromanometer.

10. The multi-point backrest speed measuring tube according to claim 1, characterized in that, The structures of all positive pressure connecting pipes and negative pressure connecting pipes are the same.

Images