A wind pressure detection device of a coal mine ventilator

Abstract

The application relates to a wind pressure detection device of a coal mine ventilator, which comprises a shell provided with a cavity, a gas hole arranged on the inner wall of the cavity, a blow-off gas channel arranged in the shell and communicated with the gas hole, a differential pressure transmitter arranged on the shell, a pitot tube movably arranged in the cavity along an axial direction and communicated with the differential pressure transmitter, an extension device arranged in the cavity, one end of which is connected with the pitot tube and the other end of which is connected with the shell, a sealing element arranged at the end of the cavity and abutting against the pitot tube to form an air-tight seal, and a negative pressure generating element communicated with the blow-off gas channel and used for generating negative pressure to form air flow from the cavity to the negative pressure generating element. The utility model fundamentally solves the problem that the static pressure hole is easy to be blocked in a high-pollution environment, and ensures long-term accuracy and reliability of the wind pressure detection data.

Description

Technical Field

[0001] This application relates to the field of coal mine ventilation technology, and in particular to a wind pressure detection device for a coal mine ventilation fan. Background Technology

[0002] Air pressure detection is a crucial aspect of safety monitoring in coal mine ventilation systems, and its accuracy directly impacts the safety of the underground working environment and the assessment of ventilation efficiency. Currently, air pressure / velocity detection devices based on the Pitot tube principle are widely used in industrial measurement. The basic principle is as follows: the Pitot tube has a total pressure orifice facing the airflow at its front end and a static pressure orifice parallel to the airflow direction on its side. According to Bernoulli's equation, the airflow stagnates at the total pressure orifice, and the measured pressure is the total pressure (the sum of static and dynamic pressures), while the static pressure orifice measures the static pressure. By measuring the difference between the total pressure and the static pressure, the dynamic pressure of the airflow can be calculated, and thus the air velocity and volume can be determined. This method is based on a classic principle, has a relatively simple structure, and offers high reliability.

[0003] However, directly applying traditional pitot tube testing devices to the air pressure testing of coal mine ventilation fans faces significant challenges. The airflow within underground coal mine ventilation ducts is rich in coal dust, water vapor, oil, and other impurities, creating a harsh environment. During long-term operation, the static pressure pores on the pitot tube surface become extremely small, making them highly susceptible to adhesion and blockage by these contaminants. Once these pores are blocked, static pressure conduction fails, leading to severe distortion in differential pressure measurements and consequently, significant errors in wind speed and air volume calculations. Furthermore, frequent pitot tube replacements would greatly increase the workload.

[0004] Therefore, there is a need for a wind pressure detection device in coal mine ventilation fans that can solve the problem of static pressure hole blockage and cleaning of Pitot tubes in highly polluted coal mine environments. Utility Model Content

[0005] Therefore, it is necessary to provide a wind pressure detection device for coal mine ventilation fans, and its specific technical solution is as follows.

[0006] A pressure detection device for a coal mine ventilation fan, comprising: The outer shell has an internal cavity; the inner wall of the cavity has air holes, and the outer shell has a sewage exhaust duct communicating with the air holes. Differential pressure transmitter, mounted on the housing; The pitot tube is movably installed in the cavity along the axial direction and is connected to the differential pressure transmitter; The telescopic device is located inside the cavity, with one end connected to the pitot tube and the other end connected to the outer shell; A sealing element is located at the end of the cavity and fits against the Pitot tube to form an airtight seal. The negative pressure generator is connected to the sewage exhaust duct and is used to generate negative pressure to form an airflow from the cavity to the negative pressure generator.

[0007] Furthermore, the pitot tube includes a body and a base, the body being connected to the base, and the base being movably disposed within the cavity along the axial direction; the cavity is provided with a stepped portion, so that the base and the stepped portion abut against each other to form a seal.

[0008] Furthermore, the base is provided with a first flexible hose and a second flexible hose; the first flexible hose connects the differential pressure transmitter and the static pressure port on the Pitot tube; the second flexible hose connects the differential pressure transmitter and the total pressure port on the Pitot tube.

[0009] Furthermore, the stepped portion is provided with multiple annular sealing rings on the side facing the base.

[0010] Furthermore, the inner wall of the cavity is provided with multiple air holes.

[0011] Furthermore, the cavity is provided with a cleaning section, which has bristles that contact the surface of the pitot tube.

[0012] Furthermore, the cleaning section is offset from the air vent.

[0013] Furthermore, the sealing element includes multiple elastic sealing flaps, one side of which is connected to the outer shell; the end of the Pitot tube near the main pressure hole has a conical outer contour; the inner contour of the multiple elastic sealing flaps of the sealing element in the closed state is the same as the conical outer contour of the Pitot tube.

[0014] Furthermore, when the Pitot tube is housed within the cavity, the elastic sealing flap fits against the conical outer contour, and adjacent elastic sealing flaps are in contact with each other.

[0015] Furthermore, a cyclone separator is provided between the sewage exhaust duct and the negative pressure generator, and a waste collection box is installed below the cyclone separator.

[0016] Beneficial Effects: The wind pressure detection device for a coal mine ventilation fan provided by this utility model, through the setting of a retractable Pitot tube and a corresponding sealed cavity, allows the Pitot tube to be stored and protected within the cavity during non-measuring periods. When cleaning is required, a negative pressure generator produces a directional airflow within the cavity. This airflow effectively flows through and draws in the static pressure holes on the surface of the Pitot tube, powerfully removing coal dust, water vapor, and other pollutants adhering to or clogging the holes and surrounding areas. This fundamentally solves the problem of easy clogging of static pressure holes in highly polluted environments, ensuring the long-term accuracy and reliability of wind pressure detection data.

[0017] The cleaning method employs negative pressure suction, with airflow moving from the inside of the static pressure orifice outwards. This effectively separates and removes blockages from the orifice, resulting in thorough cleaning. Compared to high-pressure purging, this method is gentler, avoiding the risk of permanently clogging the pipes by forcibly blowing contaminants deep into them. It also reduces the possibility of damage to the delicate static pressure orifice structure, extending the lifespan of the Pitot tube.

[0018] By incorporating a stepped section that abuts against the base, a multi-ringed sealing ring, and an elastic sealing flap, a reliable airtight seal is formed at the end of the cavity during cleaning. This design ensures the sealed environment required for negative pressure cleaning, effectively preventing pressure leakage and ensuring that the suction force is concentrated on the cleaning target. Simultaneously, the overall device has a compact structure, good protection, and can adapt to the harsh working environment of damp, dusty, and vibrating conditions in underground coal mines.

[0019] The brush scrapes the surface of the Pitot tube during its extension and retraction, achieving initial physical cleaning. Combined with negative pressure cleaning, this forms a multi-stage cleaning system of "physical scraping pretreatment + negative pressure adsorption deep cleaning," further improving cleaning efficiency and the adaptability of the device. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application 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 only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the wind pressure detection device in measurement mode; Figure 2 This is a schematic diagram of the wind pressure detection device in a clean or non-operating state; Figure 3 This is a cross-sectional view of the outer shell.

[0022] Explanation of reference numerals in the attached drawings: 1. Housing; 2. Differential pressure transmitter; 3. Pitot tube; 4. Telescopic device; 5. Seal; 6. Negative pressure generator; 7. Cyclone separator; 8. Waste collection box; 11. Cavity; 12. Air vent; 13. Sewage exhaust duct; 14. Stepped section; 15. Brush bristles; 31. Static pressure port; 32. Total pressure port; 33. Base; 34. First flexible hose; 35. Second flexible hose; 51. Elastic sealing flap. Detailed Implementation

[0023] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0024] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0028] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0029] Example Reference Figure 1-3 As shown, this embodiment provides a wind pressure detection device for a coal mine ventilation fan, including a housing 1, a differential pressure transmitter 2, a Pitot tube 3, a telescopic device 4, a sealing element 5, and a negative pressure generator 6. The housing 1 has an internal cavity 11; the inner wall of the cavity 11 has air holes 12, and the housing 1 has an internal exhaust duct 13 communicating with the air holes 12. The differential pressure transmitter 2 is mounted on the housing 1. The Pitot tube 3 is movably disposed within the cavity 11 along an axial direction, and the Pitot tube 3 is connected to the differential pressure transmitter 2; this axial direction refers to the axial direction of the Pitot tube 3. The Pitot tube 3, connected to the differential pressure transmitter 2, delivers the airflow from the static pressure port and the total pressure port to the differential pressure transmitter 2 for wind pressure detection. The telescopic device 4 is disposed within the cavity 11, with one end connected to the Pitot tube 3 and the other end connected to the housing 1. The Pitot tube 3 is moved by the telescopic device 4, so that it extends outside the cavity 11 during measurement and retracts into the cavity 11 during cleaning or non-working conditions. In this embodiment, the telescopic device 4 can be an electric telescopic rod, a cylinder, a hydraulic cylinder, or other similar equipment. A sealing element 5 is located at the end of the cavity 11 and fits against the Pitot tube 3 to form an airtight seal. The negative pressure generator 6 is connected to the exhaust duct 13 and is used to generate negative pressure, forming an airflow from the cavity 11 to the negative pressure generator 6. In this embodiment, the negative pressure generator 6 can be a Venturi vacuum generator.

[0030] It should be noted that the static pressure port 31 and the total pressure port 32 of the Pitot tube 3 are relatively independent. Therefore, when the sealing element 5 and the Pitot tube 3 are in contact to form an air seal in the clean state, the cavity 11 and the ventilation duct outside the housing form a relatively sealed state. Therefore, when the negative pressure generator 6 generates airflow, an airflow is formed from the static pressure port 31 channel - cavity 11 - sewage exhaust duct 13 - negative pressure generator 6.

[0031] The wind pressure detection device for a coal mine ventilation fan provided in this embodiment features a retractable Pitot tube 3 and a corresponding sealed cavity 11. During non-measuring periods, the Pitot tube 3 can be stored and protected within the cavity 11. When cleaning is required, a negative pressure generator 6 creates a directional airflow within the cavity 11. This airflow effectively flows through and draws in the static pressure holes 31 on the surface of the Pitot tube 3, powerfully removing coal dust, water vapor, and other pollutants adhering to or clogging the holes and surrounding areas. This fundamentally solves the problem of easy clogging of the static pressure holes 31 in highly polluted environments, ensuring the long-term accuracy and reliability of wind pressure detection data.

[0032] The cleaning method employs negative pressure suction, with airflow moving from the inside of the static pressure hole 31 outwards. This effectively separates and removes blockages from the inside of the channel, resulting in thorough cleaning. Compared to high-pressure purging, this method is gentler, avoiding the risk of permanently blocking contaminants by forcibly blowing them deep into the pipe. It also reduces the possibility of damage to the structure of the precision static pressure hole 31, extending the service life of the Pitot tube 3.

[0033] Specifically, the Pitot tube 3 includes a body and a base 33. The body is connected to the base 33, and the base 33 is movably disposed within the cavity 11 along the axial direction. The cavity 11 is provided with a stepped portion 14, which abuts against the base 33 to form a seal. The stepped portion 14 is provided with multiple annular sealing rings on the side facing the base 33.

[0034] By incorporating a stepped section 14 that abuts against the base 33, a multi-ringed sealing ring, and a sealing element 5, a reliable airtight seal is formed at the end of the cavity 11 during cleaning. This design ensures the sealed environment required for negative pressure cleaning, effectively preventing pressure leakage and ensuring that the suction force is concentrated on the cleaning target. Simultaneously, the overall device has a compact structure, good protection, and can adapt to the harsh working environment of damp, dusty, and vibrating conditions in underground coal mines.

[0035] Specifically, the base 33 is provided with a first flexible hose 34 and a second flexible hose 35; the first flexible hose 34 connects the differential pressure transmitter 2 and the static pressure port 31 on the Pitot tube 3; the second flexible hose 35 connects the differential pressure transmitter 2 and the total pressure port 32 on the Pitot tube 3. The airflow from the static pressure port 31 and the total pressure port 32 can be delivered to the differential pressure transmitter 2 through the first flexible hose 34 and the second flexible hose 35, respectively, to achieve wind pressure detection. In this embodiment, the flexible hose can also be a corrugated pipe.

[0036] Specifically, the inner wall of the cavity 11 is provided with a plurality of air holes 12. By providing a plurality of air holes 12, pollutants can be absorbed more effectively.

[0037] Specifically, the cavity 11 is further provided with a cleaning section, which has bristles 15 that contact the surface of the pitot tube 3. The cleaning section is offset from the air hole 12.

[0038] The brush scrapes the surface of the Pitot tube 3 during its extension and retraction, achieving preliminary physical cleaning. Combined with negative pressure cleaning, this forms a multi-stage cleaning system of "physical scraping pretreatment + negative pressure adsorption deep cleaning," further improving cleaning efficiency and the adaptability of the device.

[0039] Specifically, the sealing element 5 includes multiple elastic sealing flaps 51, one side of which is connected to the outer shell 1; the pitot tube 3 has a conical outer contour at one end near the main pressure hole 32; the inner contours of the multiple elastic sealing flaps 51 of the sealing element 5 in the retracted state are the same as the conical outer contour of the pitot tube 3. When the pitot tube 3 is housed in the cavity 11, the elastic sealing flaps 51 fit against the conical outer contour, and adjacent elastic sealing flaps 51 are in contact with each other. In this embodiment, the elastic sealing flaps 51 can be made of rubber or other elastic materials.

[0040] The seal 5 is configured as multiple elastic sealing flaps 51, such that in the clean state, each elastic sealing flap 51 surrounds the conical outer contour of the Pitot tube 3, thereby improving the sealing effect. It should be noted that, in order to minimize interference with the incoming flow and thus measure the "total pressure" most accurately, the prior art always sets the end of the Pitot tube 3 closest to the total pressure hole 32 to be conical.

[0041] Specifically, a cyclone separator 7 is installed between the exhaust gas duct 13 and the negative pressure generator 6, and a waste collection box 8 is installed below the cyclone separator 7. The cyclone separator 7 separates the gas and pollutants, and the pollutants are collected into the waste collection box under gravity, minimizing the impact of pollutants on the negative pressure generator 6. By setting up the cyclone separator 7 and waste collection box 8 connected to the exhaust gas duct 13, the pollutants sucked out by the negative pressure are effectively separated and collected centrally, avoiding secondary pollution caused by direct discharge of pollutants during the cleaning process, facilitating centralized treatment, and meeting the requirements of mine safety production and environmental protection.

[0042] Work process: Detection status: The Pitot tube 3 is driven by the telescopic device 4 to move out of the cavity 11, so that the total pressure port 32 and static pressure port 31 of the Pitot tube 3 are exposed to the duct of the ventilator. The airflow from the static pressure port 31 and the total pressure port 32 flows to the differential pressure transmitter 2 through the flexible hose, thereby performing wind pressure detection.

[0043] Cleaning process: The telescopic device 4 drives the Pitot tube 3 to move into the cavity 11, so that the base 33 and the step part 14 abut against each other to form an air seal. The elastic sealing flap 51 and the conical outer contour of the end of the Pitot tube 3 form an air seal. During the movement of the telescopic device 4, the surface of the Pitot tube 3 is initially cleaned by a brush. The negative pressure generator 6 is activated to form a negative pressure airflow, so that the pollutants move along the sewage channel and are collected by the sewage collection box 8 after passing through the cyclone separator 7.

[0044] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A wind pressure detection device for a coal mine ventilation fan, characterized in that, include: The outer shell has an internal cavity; the inner wall of the cavity has air holes, and the outer shell has a sewage exhaust duct communicating with the air holes. Differential pressure transmitter, mounted on the housing; The pitot tube is movably installed in the cavity along the axial direction and is connected to the differential pressure transmitter; The telescopic device is located inside the cavity, with one end connected to the pitot tube and the other end connected to the outer shell; A sealing element is located at the end of the cavity and fits against the Pitot tube to form an airtight seal. The negative pressure generator is connected to the sewage exhaust duct and is used to generate negative pressure to form an airflow from the cavity to the negative pressure generator.

2. The air pressure detection device for a coal mine ventilation fan according to claim 1, characterized in that, The Pitot tube includes a body and a base, the body and the base are connected, and the base is movably disposed in the cavity along the axial direction; the cavity is provided with a stepped portion, so that the base and the stepped portion abut against each other to form a seal.

3. The air pressure detection device for a coal mine ventilation fan according to claim 2, characterized in that, The base is provided with a first flexible hose and a second flexible hose; the first flexible hose connects the differential pressure transmitter and the static pressure port on the Pitot tube; the second flexible hose connects the differential pressure transmitter and the total pressure port on the Pitot tube.

4. The air pressure detection device for a coal mine ventilation fan according to claim 2, characterized in that, The stepped section is provided with multiple annular sealing rings on the side facing the base.

5. The air pressure detection device for a coal mine ventilation fan according to claim 1, characterized in that, The inner wall of the cavity is provided with multiple air holes.

6. The air pressure detection device for a coal mine ventilation fan according to claim 1, characterized in that, The cavity is also provided with a cleaning section, which has bristles that are in contact with the surface of the Pitot tube.

7. The air pressure detection device for a coal mine ventilation fan according to claim 6, characterized in that, The cleaning section is offset from the air vent.

8. The air pressure detection device for a coal mine ventilation fan according to claim 1, characterized in that, The sealing element includes multiple elastic sealing flaps, one side of which is connected to the outer shell; the end of the Pitot tube near the main pressure hole has a conical outer contour; the inner contour of the multiple elastic sealing flaps of the sealing element in the closed state is the same as the conical outer contour of the Pitot tube.

9. The air pressure detection device for a coal mine ventilation fan according to claim 8, characterized in that, When the Pitot tube is housed in the cavity, the elastic sealing flap fits against the conical outer contour, and adjacent elastic sealing flaps are in contact with each other.

10. The air pressure detection device for a coal mine ventilation fan according to claim 1, characterized in that, A cyclone separator is provided between the sewage exhaust duct and the negative pressure generator, and a waste collection box is installed below the cyclone separator.

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