CN205301358U - Take fixing device's pin type pitot tube - Google Patents

Abstract

The utility model discloses a needle-type bi-tube tube with a fixing device, a bi-tube tube and a tube body fixing device, the tube body of the bi-tube tube is L-shaped with a 90° elbow, and the tube body is divided into an X-axis tube in the horizontal direction and an X-axis tube in the horizontal direction. The Y-axis tube in the vertical direction, the Y-axis tube runs through the through hole of the tube body fixing device, and the Pitot tube body is only provided with openings at both ends, and the rest are hermetically sealed. Pitot tube pipe area is less than 2% of the measured pipe area. The pipe body fixing device includes: a lower concave block, a sealing ring and an upper convex block, and the upper convex block is embedded in the groove of the lower concave block; the sealing ring is placed at the bottom of the groove; the upper opening of the lower concave block, the sealing ring and the upper convex block There is a through hole for accommodating the pipe body; the sealing ring is made of elastic material. The utility model solves the problem of internal flow distribution measurement in small pipelines, and can easily adjust and realize the position and angle of the end-to-end tube. At the same time, the full pressure of the high-speed fluid can be accurately controlled, and the interference to the entire flow field is also greatly reduced. It is suitable for Modern precision measurement or teaching requirements.

Description

A needle-type Pitot tube with a fixing device

technical field

The utility model belongs to the field of fluid measuring instruments, in particular to a needle-type Pitot tube with a fixing device.

Background technique

In scientific research, production, teaching, environmental protection, clean room, mine ventilation, and energy management departments, Pitot tubes are often used to measure the wind speed of the pipeline and the air velocity in the flue of the kiln. After conversion, the flow rate can be determined, and the water flow velocity in the pipeline can also be measured. Using Pitot tubes to measure speed and determine flow has a reliable theoretical basis, is easy to use, and is accurate. It is a classic and extensive measurement method. In addition, it can also be used to measure the pressure of fluids. Pitot is a commonly used experimental tool in courses and experiments in today's colleges and universities, especially in fluid mechanics experiments. Pitot tubes should correctly select the cross-section of the measuring point during the experiment to ensure that the measuring point is in the straight pipe section where the air flow is smooth. For this reason, the relative requirements for Pitot tubes are relatively high, such as: elbows, variable-diameter special-shaped pipes and other local components in the measurement section away from the direction of flow should be more than 4 times the diameter of the pipe; local elbows and variable-diameter structures in the downstream direction should be More than 2 times the diameter of the pipe, etc., the Pitot tubes for measuring gas and liquid have different structures due to different medium densities.

Traditional Pitot tubes are often bulky to achieve their purpose of use, and the measurement process greatly interferes with the entire flow field. They can only be used in outflows or large pipelines, and the flow velocity range is narrow. ～2m/s, the speed measurement range of air Pitot tube is 1～60m/s, if the flow velocity range of water or air exceeds the limit, or in some aspects, such as internal flow problems in small pipes, measurement of subtle flow velocity difference distribution, etc., Traditional Pitot trust is useless, and other traditional experimental methods are also useless. Unless advanced methods such as PIV and other expensive unconventional methods are used, people can only analyze or estimate theoretically, and cannot accurately measure through conventional methods.

In view of this, it is urgent to design a new measurement method to realize the application of the current measurement blind zone.

In addition, currently, there is no better way to fix small-sized Pitot tubes. Pitot tubes are usually used to detect the airflow velocity in some pipelines or wind tunnels. As mentioned earlier, the addition of pitot tubes should minimize the impact on the shape of the fluid itself. Therefore, if other fixtures are introduced into the wind tunnel, the turbulence will inevitably increase, which will greatly interfere with the measurement results. Based on this consideration, it is necessary to develop a device that can fix the pitot tube on the wall of the device or other positions while minimizing interference.

Contents of the invention

The purpose of this utility model is to solve the problems existing in the prior art, and to provide a needle-type Bi-tube tube with a fixing device. The specific technical scheme is as follows:

A needle-type Pitot tube with a fixing device, including a Pitot tube and a tube body fixing device. The Pitot tube body is L-shaped with a 90° elbow, and the tube body is divided into a horizontal X-axis tube and a vertical Y-axis tube. The shaft tube and the Y-axis tube run through the through hole of the tube body fixing device, and the Pitot tube body is only provided with openings at both ends, and the rest are hermetically sealed. That is to say, only the total pressure tube is set in the Pitot tube, and the pressure measuring tube for measuring the static pressure is not set.

In order to reduce the interference of the Pitot tube to the fluid form, preferably, the area of the Pitot tube is less than 2% of the area of the measurement tube. Because the traditional Pitot tube needs to install the total pressure tube and the static pressure tube at the same time in the tube body, it is usually impossible to make the tube body into a needle type with a small hole diameter, so it will have a great influence on the fluid form.

Preferably, scales are arranged on the Y-axis tube of the Pitot tube body.

Preferably, the pipe body fixing device includes: a lower concave block, a sealing ring and an upper bump, the upper bump is embedded in the groove of the lower concave block, so that the upper bump can move up and down in the groove; the sealing ring is placed At the bottom of the groove; the lower concave block, the sealing ring and the upper bump are provided with through holes for accommodating the pipe body; the sealing ring is made of elastic material, which is used for deformation and clamping when squeezed by the upper bump tube body.

Any connection method can be used between the upper convex block and the lower concave block, as long as the upper convex block and the lower concave block can slide in a damping manner, that is, the upper convex block can be fixed at a certain position in the groove , to achieve the compression of the sealing ring. As a further preference, the upper convex block and the lower concave block are connected by threads. Through convenient rotation, the upper convex block can be embedded in the lower concave block.

In order to better maintain the stability of the Pitot tube, it is necessary to increase the contact length and area between the fixing device and the tube body as much as possible. As a further preference, the bottom of the lower concave block is also provided with a cylindrical extension block extending along the direction of the pipe body, and a through hole for accommodating the pipe body is also opened on the extension block, and the through hole is sealed with the lower concave block and the pipe body. The ring and the through hole on the upper bump pass through. The through holes on the above four parts are combined to accommodate the pipe body. The extension block can also be used as a fixed end and directly inserted into the wall of the tube to be tested.

As a still further preference, threads are provided on the outer wall of the extension block;

As a further preference, the extension block is covered with a gasket, so that the gas or liquid below the airtight part cannot overflow, and the airtightness is maintained.

Since the bottom of the Pitot tube usually protrudes into the device under test, it must be ensured that the inlet of the Pitot tube is facing the direction of fluid flow during the measurement. Preferably, the upper part of the Pitot tube body is fixed with a guide rod showing the orientation of the Pitot tube entrance.

As a further preference, the direction of the guide rod is consistent with the direction of the X-axis tube in the horizontal direction of the Pitot tube body, and the direction of the X-axis tube at the bottom can be directly determined through the guide rod, and it can also be used as a force point for adjusting the direction .

The beneficial effect of the utility model relative to the prior art is:

1) Aiming at the problem of fixing the Pitot tube, the utility model proposes a uniquely designed fixing device, which can fix the Pitot tube or other tubes on the device through easy adjustment, and greatly reduces the influence on the internal fluid;

2) A needle-type Pitot tube that only needs to measure the total pressure is designed. The pipe diameter is small, which is especially suitable for the flow velocity distribution measurement of the internal flow problems such as thin pipes. For the high-speed flow field of the wind tunnel, the wind pressure can be easily measured. Thus, the flow rate is converted.

3) The scale is arranged on the Y-axis of the Pitot tube, so that the functional relationship between the spatial distance and the pressure distribution can be measured in one step when the Pitot tube is working, which greatly improves the experimental efficiency and the accuracy of the measured value;

4) A guide rod is set on the Y-axis of the Pitot tube, which can easily adjust the measurement direction and angle of the pressure detection hole of the Pitot tube's X-axis tube, which greatly improves the experimental efficiency and the accuracy of the measured value.

Description of drawings

Fig. 1 is a structural representation of a pin-type Pitot tube with a fixing device;

Fig. 2 is the structural representation of the pin-type Pitot tube of the present utility model;

Fig. 3 is a kind of realization mode of the pipe fixing device of the present invention;

Fig. 4 is another implementation of the pipe fixing device of the present invention;

Fig. 5 is the arrangement mode of the gasket of the present utility model;

Fig. 6 is the setting method of the guide rod of the present invention.

In the figure: Pitot tube 1, tube fixing device 2, guide rod 3, X-axis tube 101, Y-axis tube 102, upper bump 201, sealing ring 202, lower concave block 203, extension block 204, washer 205.

detailed description

Below in conjunction with accompanying drawing, the utility model is further elaborated and illustrated. The technical features of each embodiment in the utility model can be combined correspondingly on the premise that there is no mutual conflict.

As shown in FIG. 1 , a needle-type Pitot tube with a fixing device includes a Pitot tube 1 and a tube body fixing device 2 . The shape of Pitot tube 1 is shown in Figure 2. The tube body is L-shaped with a 90° elbow. The tube body is divided into an X-axis tube 101 in the horizontal direction and a Y-axis tube 102 in the vertical direction. The X-axis tube 101 and the Y-axis tube 101 are Tube 102 communicates. The Y-axis tube 102 runs through the through hole of the tube fixing device 2 . The pipe body of Pitot tube 1 is only provided with openings at both ends, and the rest are hermetically sealed. The pressure probe hole is disposed at the end of the X-axis tube 101 . That is to say, only the total pressure tube is set in the Pitot tube, and the pressure measuring tube for measuring the static pressure is not set.

The traditional Pitot tube needs to install the total pressure tube and the static pressure tube at the same time in the tube body. Therefore, under the current technological level, it is usually impossible to make the tube body into a needle type with a small hole diameter, so it will have a great impact on the fluid form. In order to reduce the interference of the Pitot tube to the fluid form, the pipe area of the Pitot tube 1 is less than 2% of the measurement pipe area, which can meet the requirement of accurate measurement. Scales are arranged on the Y-axis tube 102 of the Pitot tube 1 tube body, so that the liquid level can be easily read. The Pitot tube 1 can be used for the flow velocity measurement of liquid and the flow velocity measurement of gas. The pitot tube omits the pressure measuring tube used to detect the static pressure, and is directly used to measure the total pressure. If you need to know the static pressure, you can convert it by the depth of the bottom of the Pitot tube immersed in the liquid. And because of the structural change, it is possible to reduce its size.

The pipe body fixing device can be implemented in various ways, such as buckles or other fastening elements. The utility model discloses a specially designed device. As shown in Figure 3, the pipe body fixing device 2 in the utility model is composed of a lower concave block 203, a sealing ring 202 and an upper convex block 201, and the upper convex block 201 is embedded in the groove of the lower concave block 203, so that the upper convex block 201 can move up and down in the groove; the sealing ring 202 is placed at the bottom of the groove; the lower concave block 203, the sealing ring 202 and the upper convex block 201 have through holes for accommodating the pipe body; the sealing ring 202 adopts elastic material. Therefore, when the sealing ring 202 is pressed by the upper protrusion 201, it will be deformed, so that the diameter of the cavity in the middle of the ring body will be reduced, thereby clamping the tube body.

Any connection method can be adopted between the upper convex block 201 and the lower concave block 203 , as long as the upper convex block 201 can be slidably fixed at a certain position of the groove to realize the compression of the sealing ring 202 . In this embodiment, the upper convex block 201 and the lower concave block 203 are connected by threads.

The fixing method of the above-mentioned device is: put the sealing ring 202 into the groove of the lower concave block 203, insert the Y-axis tube 102 of the Pitot tube into the through hole of the tube body fixing device 2, and then tighten the upper convex block 201, The X-axis tube 101 goes deep into the fluid to be tested, and the tube body fixing device 2 is fixed on the tube wall of the tube to be tested by fasteners such as buckles.

In addition, the utility model also provides another fixing method. As shown in Figure 4, the bottom of the lower concave block 203 is also provided with a cylindrical extension block 204 extending along the direction of the pipe body, and the extension block 204 is also provided with a through hole for accommodating the pipe body, and the through hole is connected with the lower concave block 203, The sealing ring 202 is connected with the through hole on the upper bump 201 . The method of using this tube body fixing device is: put the sealing ring 202 into the groove of the lower concave block 203, insert the Y-axis tube 102 of the Pitot tube into the through hole of the tube body fixing device 2, and then tighten the upper bump 201. Drill a hole matching the diameter of the extension block 204 on the wall of the tube to be fixed, insert the X-axis tube 101 into the fluid to be measured, and then directly insert the extension block 204 into the hole for fixing.

In order to make the fixing of the extension block 204 more firm and convenient, the outer wall of the extension block 204 is provided with threads, which can be screwed into the pipe wall. In order to maintain airtightness, a gasket 205 may also be set on the extension block.

In order to adjust the direction of the pressure detection hole, the upper part of the pipe body of the Pitot tube 1 is fixed with a guide rod 3 showing the direction of the entrance of the Pitot tube 1 . The direction of the guide rod 3 is preferably consistent with the direction of the X-axis tube 101 in the horizontal direction of the Pitot tube 1 tube body.

In the actual use process, the Pitot tube of the utility model can be fixed on the position to be tested, the Y-axis tube 102 of the Pitot tube 3 is connected with a pressure gauge or a pressure sensor, and the port pressure detection hole of the X-axis tube 101 is aligned with the guide rod 3 Adjust the height of the fluid to be measured, and the pressure of the part to be measured can be measured by a manometer or a pressure sensor, so as to convert the flow rate.

The embodiments described above are only several preferred solutions of the present utility model, but they are not intended to limit the present utility model. within the scope of protection.

Claims (10)

1. A needle-type Pitot tube with a fixing device, characterized in that it includes a Pitot tube (1) and a tube body fixing device (2), and the tube body of the Pitot tube (1) is L-shaped with a 90° elbow, The tube body is divided into the X-axis tube (101) in the horizontal direction and the Y-axis tube (102) in the vertical direction. The Y-axis tube (102) runs through the through hole of the tube body fixing device (2). The body is only provided with openings at both ends, and the rest are hermetically sealed. 2. The needle-type Pitot tube with fixing device according to claim 1, characterized in that, the pipe area of the Pitot tube (1) is less than 2% of the area of the measurement pipe. 3 . The pin-type Pitot tube with fixing device according to claim 1 , characterized in that, scales are arranged on the Y-axis tube ( 102 ) of the Pitot tube ( 1 ) body. 4 . 4. The needle-type Pitot tube with fixing device according to claim 1, characterized in that, the tube body fixing device (2) comprises: a lower concave block (203), a sealing ring (202) and an upper convex block (201), the upper bump (201) is embedded in the groove of the lower concave block (203), so that the upper bump (201) can move up and down in the groove; the sealing ring (202) is placed at the bottom of the groove; the lower The concave block (203), the sealing ring (202) and the upper bump (201) are provided with a through hole for accommodating the pipe body; the sealing ring (202) is made of elastic material, which is used for receiving the upper bump (201) ) deforms and clamps the tube body when it is squeezed. 5. The needle-type Pitot tube with fixing device according to claim 4, characterized in that, the upper convex block (201) and the lower concave block (203) are connected by threads. 6. The needle-type Pitot tube with fixing device according to claim 5, characterized in that, the bottom of the lower concave block (203) is also provided with a cylindrical extension block (204) extending along the direction of the tube body, extending A through hole for accommodating the pipe body is also opened on the block (204), and the through hole communicates with the through holes on the lower concave block (203), the sealing ring (202) and the upper convex block (201). 7. The needle-type Pitot tube with a fixing device according to claim 6, wherein the outer wall of the extension block is provided with threads. 8 . The needle-type Pitot tube with a fixing device according to claim 6 , wherein a washer ( 205 ) is sheathed on the extension block. 9. The needle-type Pitot tube with fixing device according to claim 1, characterized in that, the upper part of the Pitot tube (1) body is fixed with a guide rod (3) showing the orientation of the Pitot tube (1) entrance. 10. The pin-type Pitot tube with fixing device according to claim 9, characterized in that, the direction of the guide rod (3) is consistent with the direction of the X-axis tube (101) in the horizontal direction of the Pitot tube (1) tube body .