Electromagnetic flowmeter for measuring gas flow

Abstract

The invention discloses an electromagnetic flowmeter for measuring gas flow, and belongs to the technical field of electromagnetic flowmeters.The electromagnetic flowmeter comprises a mounting mechanism, a measuring mechanism, a switching mechanism, a mounting cylinder and a pressure relief mechanism, the mounting mechanism comprises a pipe body and a mounting assembly, the mounting assembly is connected with the pipe body, and the measuring mechanism comprises a first mounting frame and a rotating speed detection assembly; the rotating speed detection assembly is connected with the pipe body; the first mounting frame is connected with the mounting assembly; the switch mechanism comprises a driving shaft, a pressing block and a transmission assembly, the driving shaft is installed on the outer surface of the pipe body and connected with the transmission assembly, the transmission assembly is connected with the pressing block, and the pressing block is installed on the side face of the pipe body; the installation cylinder is installed on the pipe body, the pressure relief mechanism comprises a lifting rod, a ventilation cylinder, a pressure intensity measuring assembly and a pressure relief assembly, one part of the lifting rod is installed in the installation cylinder, the part, installed outside the installation cylinder, of the lifting rod is connected with the pressure intensity measuring assembly, and the pressure intensity measuring assembly is connected with the pipe body and connected with the pressure relief assembly; the pressure relief assembly is connected with the pipe body.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic flowmeters, and particularly discloses an electromagnetic flowmeter for measuring gas flow. Background Art

[0002] Gas flow measurement is a key technology in fields such as chemical industry, energy, environmental protection, and medical equipment. Traditional electromagnetic flowmeters are based on Faraday's law of electromagnetic induction and calculate the flow rate by measuring the electromotive force generated when a conductive fluid cuts the magnetic induction line. However, gas media generally have non-conductivity, resulting in the inability to directly apply classical electromagnetic flowmeters to gas measurement. The patent with the publication number CN216159948U discloses a gas electromagnetic flowmeter capable of stabilizing air flow. The technical solution of this patent is as follows: It includes a flowmeter body, an intelligent measurement meter is installed at the upper end of the flowmeter body, connection flanges are installed at both ends of the flowmeter body, flow stabilizing plate mechanisms are installed at the upper and lower ends inside the inlet end of the flowmeter body, a front flow stabilizing tube is arranged behind the flow stabilizing plate mechanism, and the outer wall of the front flow stabilizing tube is hermetically connected to the flowmeter body. The rear end of the front flow stabilizing tube is connected to a flow stabilizing straight tube body, the rear end of the flow stabilizing straight tube body is connected to an exhaust pipe, an inner tube body is arranged inside the outer tube body, the inner tube body and the outer tube body are concentrically arranged, and several connecting rods are connected to the outer side wall of the inner tube body. The outer ends of the several connecting rods are connected to the inner side wall of the outer tube body. However, when the gas pressure inside the tube body is too high, it cannot be relieved, which easily leads to damage to the tube body. Therefore, a gas electromagnetic flowmeter capable of stabilizing air flow is invented to address this defect. Summary of the Invention

[0003] In view of the above technical problems, the technical solution adopted by the present invention is: An electromagnetic flowmeter for measuring gas flow includes an installation mechanism, a measurement mechanism, a switch mechanism, an installation cylinder, and a pressure relief mechanism. The installation mechanism includes a tube body and an installation component, the installation component is connected to the tube body. The measurement mechanism includes a first installation frame and a rotation speed detection component, the rotation speed detection component is connected to the tube body, and the first installation frame is connected to the installation component. The switch mechanism includes a driving shaft, a pressing block, a switch component, and a transmission component. The driving shaft is installed on the outer surface of the tube body, the driving shaft is connected to the transmission component, the transmission component is connected to the pressing block, the transmission component is connected to the switch component, and the pressing block is installed on the side of the tube body.

[0004] The installation cylinder is installed on the tube body. The pressure relief mechanism includes a lifting rod, a ventilation cylinder, a pressure measurement component, and a pressure relief component. A part of the lifting rod is installed inside the installation cylinder, the part of the lifting rod installed outside the installation cylinder is connected to the pressure measurement component, the pressure measurement component is connected to the tube body, the pressure measurement component is connected to the pressure relief component, and the pressure relief component is connected to the tube body.

[0005] Further, the installation component includes an air outlet pipe and an air inlet pipe. The air outlet pipe and the air inlet pipe are installed on two end faces of the pipe body. The outer surface of the pipe body is provided with a first mounting hole, a second mounting hole, a third mounting hole, and a fourth mounting hole. The axial directions of the first mounting hole and the second mounting hole are parallel, the axial directions of the third mounting hole and the fourth mounting hole are parallel, the axial direction of the first mounting hole and the axial direction of the third mounting hole are perpendicular, and the axial directions of the pipe body, the first mounting hole, and the third mounting hole are perpendicular to each other. The mounting cylinder is installed on the inner wall of the first mounting hole, and the ventilation cylinder is installed on the inner wall of the second mounting hole.

[0006] Further, the pressure measuring component includes a rotating shaft. The rotating shaft is rotatably installed on the inner wall of the third mounting hole. A part of the rotating shaft extends into the pipe body. A rotating rod is fixedly installed on the outer surface of the part of the rotating shaft that extends into the pipe body. A detection head is fixedly installed on the outer surface of the part of the rotating shaft that does not extend into the pipe body. The measuring mechanism further includes a first mounting bracket and a second mounting bracket. The air inlet pipe is fixedly installed on the first mounting bracket, and the air outlet pipe is fixedly installed on the second mounting bracket. A mounting rod is fixedly installed on the side of the first mounting bracket, and a rotation measuring instrument is fixedly installed on the side of the mounting rod.

[0007] Further, there are two sets of transmission components. Each set of transmission components includes a driving shaft. The driving shaft is rotatably installed on the inner wall of the fourth mounting hole. A first spring is wound around the outer surface of the driving shaft. One end of the first spring is fixedly installed on the outer surface of the driving shaft, and the other end of the first spring is fixedly installed on the outer surface of the pipe body. A part of the driving shaft extends into the pipe body. A rotating fan blade is fixedly installed on the outer surface of the part of the driving shaft that extends into the pipe body. A rotating fan blade is fixedly installed on the outer surface of the part of the driving shaft that extends into the pipe body. A turntable is fixedly installed on the outer surface of the part of the driving shaft that does not extend into the pipe body. A scale is provided on the side of the turntable. A turntable is also rotatably installed on the outer surface of the part of the driving shaft that does not extend into the pipe body. The turntable is located on the side of the turntable away from the pipe body. A third mounting bracket is rotatably installed on the outer surface of the driving shaft. The first pointer is fixedly connected to the third mounting bracket. An intermediate plate is fixedly installed on the side of the third mounting bracket. The intermediate plate is fixedly installed between the first mounting bracket and the second mounting bracket.

[0008] Further, there are two sets of switch components. The two sets of switch components are symmetrically installed on two end faces of the pipe body. Each set of switch components includes a first connecting rod and a fixed sleeve. The two first connecting rods are respectively rotatably connected to a turntable. The two fixed sleeves are symmetrically fixedly installed on two end faces of the pipe body. The two fixed sleeves are coaxial with the air outlet pipe and the air inlet pipe respectively. A limiting track is fixedly installed on each fixed sleeve. A slider is slidably installed on the side of the limiting track. A pressing block is fixedly installed below the slider. The lower part of the pressing block is semi-circular. A driving plate is fixedly installed on the side of the slider. A second connecting rod is fixedly installed on the side of the driving plate. The two second connecting rods are respectively rotatably connected to a first connecting rod.

[0009] Further, the installation cylinder is fixedly installed on the inner wall of the first installation hole. The pressure measurement assembly is provided with a lifting plate, which is slidably installed on the inner wall of the installation cylinder. A fixed plate is also fixedly installed on the inner wall of the installation cylinder, and the fixed plate is located above the lifting plate. A sliding shaft is fixedly installed on the lifting plate, and the sliding shaft is slidably connected to the fixed plate. A second spring is wound around the outer surface of the sliding shaft. One end of the second spring is fixedly installed on the outer surface of the sliding shaft, and the other end of the second spring is fixedly installed on the fixed plate. The fixed plate is slidably connected to the lifting rod.

[0010] Further, the lower part of the lifting rod is hemispherical, and the lower part of the lifting rod is tangent to the lifting plate. A third spring is wound around the outer surface of the lifting plate. One end of the third spring is fixedly installed on the lifting rod, and the other end of the third spring is fixedly installed on the fixed plate. A driving rod and a third connecting rod are fixedly installed on the lifting rod. A chute is arranged on the outer surface of the lifting rod, and both the driving rod and the third connecting rod are slidably installed on the inner wall of the chute. A second pointer is fixedly installed on the side of the driving rod, a scale plate is slidably installed on the side of the second pointer, and scales are arranged on the side of the scale plate.

[0011] Further, a vertical rod is fixedly installed on the third connecting rod, and a fourth connecting rod is fixedly installed on the outer surface of the vertical rod. The pressure relief assembly includes a piston shaft, the piston shaft is fixedly installed at the lower part of the fourth connecting rod, a piston is arranged at the lower part of the piston shaft, and the piston at the lower part of the piston shaft is slidably connected to the ventilation cylinder. A discharge pipe is fixedly installed on the outer surface of the ventilation cylinder, and the discharge pipe is communicated with the inside of the ventilation cylinder. In the initial state, the piston at the lower part of the piston shaft is located below the discharge pipe.

[0012] The beneficial effects of the present invention compared with the prior art are as follows: (1) Measure the gas pressure in the pipe body, and relieve the pressure inside the pipe body when the gas pressure is too high; (2) Close the air inlet and outlet when the gas pressure is too high, so as to facilitate the pressure relief process; (3) Detect the gas flow rate and gas pressure in the pipe simultaneously, so as to improve work efficiency. Description of the Drawings

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0014] Figure 2 It is a schematic diagram of the structure of the measurement mechanism of the present invention.

[0015] Figure 3 It is a schematic diagram of the structure of the switch mechanism of the present invention.

[0016] Figure 4 It is Figure 3 a partial enlarged structural schematic diagram at A in

[0017] Figure 5 It is a schematic diagram of the structure of the pressure relief mechanism of the present invention.

[0018] Figure 6 It isFigure 5 Schematic diagram of the partially enlarged structure at position B in [the figure].

[0019] Figure 7 is Figure 5 Schematic diagram of the partially enlarged structure at position C in [the figure].

[0020] Figure 8 Schematic diagram of the internal structure of the installation cylinder of the present invention.

[0021] Reference numerals: 1 - installation mechanism; 2 - measuring mechanism; 3 - switch mechanism; 4 - installation cylinder; 5 - pressure relief mechanism; 101 - pipe body; 102 - air outlet pipe; 103 - air inlet pipe; 104 - first installation hole; 105 - second installation hole; 106 - third installation hole; 107 - fourth installation hole; 201 - first installation frame; 202 - installation rod; 203 - rotary measuring instrument; 204 - rotating rod; 205 - rotating shaft; 206 - detection head; 207 - intermediate plate; 208 - second installation frame; 209 - third installation frame; 301 - driving shaft; 302 - first pointer; 303 - turntable; 304 - rotating fan blade; 305 - first spring; 306 - first connecting rod; 307 - second connecting rod; 308 - driving plate; 309 - limiting track; 310 - slider; 311 - fixed sleeve; 312 - pressing block; 501 - lifting rod; 502 - driving rod; 503 - third connecting rod; 504 - second pointer; 505 - scale plate; 506 - vertical rod; 507 - fourth connecting rod; 508 - piston shaft; 509 - air release pipe; 510 - ventilation cylinder; 511 - chute; 512 - fixing plate; 513 - sliding shaft; 514 - second spring; 515 - lifting plate; 516 - third spring. Detailed implementation manners

[0022] The technical solution of the present invention will be further described below in conjunction with and through specific implementation manners.

[0023] Among them, the attached drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to this patent; in order to better illustrate the embodiments of the present invention, some components in the attached drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the attached drawings may be omitted.

[0024] As shown in the attached Figure 1 ~attached '' Figure 7As shown, the installation mechanism 1 includes a pipe body 101 and an installation component. The installation component is connected to the pipe body 101. The measurement mechanism 2 includes a first mounting bracket 201 and a rotational speed detection component. The rotational speed detection component is connected to the pipe body 101. The first mounting bracket 201 is connected to the installation component; the switch mechanism 3 includes a driving shaft 301, a pressing block 312, a switch component, and a transmission component. The driving shaft 301 is installed on the outer surface of the pipe body 101. The driving shaft 301 is connected to the transmission component. The transmission component is connected to the pressing block 312. The transmission component is connected to the switch component. The pressing block 312 is installed on the side of the pipe body 101; the installation cylinder 4 is installed on the pipe body 101. The pressure relief mechanism 5 includes a lifting rod 501, a ventilation cylinder 510, a pressure measurement component, and a pressure relief component. A part of the lifting rod 501 is installed inside the installation cylinder 4. The part of the lifting rod 501 installed outside the installation cylinder 4 is connected to the pressure measurement component. The pressure measurement component is connected to the pipe body 101. The pressure measurement component is connected to the pressure relief component. The pressure relief component is connected to the pipe body 101. The air outlet pipe 102 and the air inlet pipe 103 are both flexible hoses.

[0025] As shown in the attached Figure 2 ~ attached Figure 6 As shown, the installation component includes an air outlet pipe 102 and an air inlet pipe 103. The air outlet pipe 102 and the air inlet pipe 103 are installed on two end faces of the pipe body 101. The outer surface of the pipe body 101 is provided with a first mounting hole 104, a second mounting hole 105, a third mounting hole 106, and a fourth mounting hole 107. The axial directions of the first mounting hole 104 and the second mounting hole 105 are parallel. The axial directions of the third mounting hole 106 and the fourth mounting hole 107 are parallel. The axial directions of the first mounting hole 104 and the third mounting hole 106 are perpendicular. The axial directions of the pipe body 101, the first mounting hole 104, and the third mounting hole 106 are perpendicular to each other. The installation cylinder 4 is installed on the inner wall of the first mounting hole 104. The ventilation cylinder 510 is installed on the inner wall of the second mounting hole 105; the pressure measurement component includes a rotating shaft 205. The rotating shaft 205 is rotatably installed on the inner wall of the third mounting hole 106. A part of the rotating shaft 205 extends into the pipe body 101. A rotating rod 204 is fixedly installed on the outer surface of the rotating shaft 205 extending into the pipe body 101. A detection head 206 is fixedly installed on the outer surface of the rotating shaft 205 that does not extend into the pipe body 101. The measurement mechanism 2 further includes a first mounting bracket 201 and a second mounting bracket 208. The air inlet pipe 103 is fixedly installed on the first mounting bracket 201. The air outlet pipe 102 is fixedly installed on the second mounting bracket 208. An installation rod 202 is fixedly installed on the side of the first mounting bracket 201. A rotation measurement instrument 203 is fixedly installed on the side of the installation rod 202. The rotation measurement instrument 203 detects the rotational speed of the detection head 206.

[0026] As shown in the attached Figure 3 ~ attached Figure 7As shown in the figure, there are two sets of transmission components. Each set of transmission components includes a driving shaft 301. The driving shaft 301 is rotatably installed on the inner wall of the fourth installation hole 107. A first spring 305 is wound around the outer surface of the driving shaft 301. One end of the first spring 305 is fixedly installed on the outer surface of the driving shaft 301, and the other end of the first spring 305 is fixedly installed on the outer surface of the pipe body 101. A part of the driving shaft 301 extends into the pipe body 101. A rotating fan blade 304 is fixedly installed on the outer surface of the part of the driving shaft 301 that extends into the pipe body 101. A rotating fan blade 304 is fixedly installed on the outer surface of the part of the driving shaft 301 that extends into the pipe body 101. A turntable 303 is fixedly installed on the outer surface of the part of the driving shaft 301 that does not extend into the pipe body 101. A scale is provided on the side surface of the turntable 303. A turntable 303 is also rotatably installed on the outer surface of the part of the driving shaft 301 that does not extend into the pipe body 101. The turntable 303 is located on the side surface of the turntable 303 away from the pipe body 101. A third mounting bracket 209 is rotatably installed on the outer surface of the driving shaft 301. The first pointer 302 is fixedly connected to the third mounting bracket 209. An intermediate plate 207 is fixedly installed on the side surface of the third mounting bracket 209. The intermediate plate 207 is fixedly installed between the first mounting bracket 201 and the second mounting bracket 208; there are two sets of switch components. The two sets of switch components are symmetrically installed on the two end faces of the pipe body 101. Each set of switch components includes a first connecting rod 306 and a fixed sleeve 311. The two first connecting rods 306 are respectively rotatably connected to a turntable 303. The two fixed sleeves 311 are symmetrically fixedly installed on the two end faces of the pipe body 101. The two fixed sleeves 311 are respectively coaxial with the air outlet pipe 102 and the air inlet pipe 103. A limiting track 309 is fixedly installed on each fixed sleeve 311. A slider 310 is slidably installed on the side surface of the limiting track 309. A pressing block 312 is fixedly installed on the lower part of the slider 310. The lower part of the pressing block 312 is semicircular. A driving plate 308 is fixedly installed on the side surface of the slider 310. A second connecting rod 307 is fixedly installed on the side surface of the driving plate 308. The two second connecting rods 307 are respectively rotatably connected to a first connecting rod 306.

[0027] As shown in the attached Figure 4 ~ attached Figure 8As shown in the figure, the installation cylinder 4 is fixedly installed on the inner wall of the first installation hole 104. The pressure measurement assembly is provided with a lifting plate 515, which is slidably installed on the inner wall of the installation cylinder 4. A fixed plate 512 is also fixedly installed on the inner wall of the installation cylinder 4, and the fixed plate 512 is located above the lifting plate 515. A sliding shaft 513 is fixedly installed on the lifting plate 515, and the sliding shaft 513 is slidably connected with the fixed plate 512. A second spring 514 is wound around the outer surface of the sliding shaft 513. One end of the second spring 514 is fixedly installed on the outer surface of the sliding shaft 513, and the other end of the second spring 514 is fixedly installed on the fixed plate 512. The fixed plate 512 is slidably connected with the lifting rod 501; the lower part of the lifting rod 501 is hemispherical, and the lower part of the lifting rod 501 is tangent to the lifting plate 515. A third spring 516 is wound around the outer surface of the lifting plate 515. One end of the third spring 516 is fixedly installed on the lifting rod 501, and the other end of the third spring 516 is fixedly installed on the fixed plate 512. A driving rod 502 and a third connecting rod 503 are fixedly installed on the lifting rod 501. A chute 511 is arranged on the outer surface of the lifting rod 501, and both the driving rod 502 and the third connecting rod 503 are slidably installed on the inner wall of the chute 511. Second pointers 504 are fixedly installed on the sides of the driving rod 502 and the third connecting rod 503, and a scale plate 505 is slidably installed on the side of the second pointer 504, and scales are arranged on the side of the scale plate 505; a vertical rod 506 is fixedly installed on the third connecting rod 503, and a fourth connecting rod 507 is fixedly installed on the outer surface of the vertical rod 506. The pressure relief assembly includes a piston shaft 508, and the piston shaft 508 is fixedly installed at the lower part of the fourth connecting rod 507. A piston is arranged at the lower part of the piston shaft 508, and the piston at the lower part of the piston shaft 508 is slidably connected with the ventilation cylinder 510. A pressure relief pipe 509 is fixedly installed on the outer surface of the ventilation cylinder 510, and the pressure relief pipe 509 is communicated with the inside of the ventilation cylinder 510. In the initial state, the piston at the lower part of the piston shaft 508 is located below the pressure relief pipe 509.

[0028] The working principle of the present invention is as follows.

[0029] (1) Before starting to work, the rotation measuring instrument 203 is started, and the gas is sent into the pipe body 101 through the air outlet pipe 102 and discharged through the air inlet pipe 103. When the gas passes through the pipe body 101, the rotating rod 204 drives the rotating shaft 205 to rotate under the action of the gas, and the rotating shaft 205 drives the detection head 206 to rotate. When the rotation speed of the detection head 206 is constant, the rotation speed of the detection head 206 is measured by the rotation measuring instrument 203, so as to detect the flow velocity of the gas in the pipe body 101. The result obtained by multiplying the flow velocity of the gas by the cross-sectional area of the pipe body 101 is the gas flow rate.

[0030] (2) Under the action of the gas in the pipe body 101, the rotating fan blade 304 rotates. When the force generated by the pipe body 101 blowing the rotating fan blade 304 reaches an equilibrium with the elastic force of the first spring 305, the rotating fan blade 304 stops rotating. At this time, the driving shaft 301 drives the turntable 303 to rotate, so as to display the pressure in the pipe body 101 through the scale on the turntable 303. When the gas pressure in the pipe body 101 is too high, the first connecting rod 306 is driven to move under the action of the turntable 303. The first connecting rod 306 drives the driving plate 308 to move through the second connecting rod 307. The driving plate 308 drives the pressing block 312 to descend through the slider 310. Furthermore, the semicircle at the lower part of the pressing block 312 closes the air outlet pipe 102 and the air inlet pipe 103, thereby stopping the supply and discharge of gas.

[0031] (3) When the gas pressure in the pipe body 101 is too high, the lifting plate 515 rises along the installation cylinder 4. At this time, the lifting plate 515 pushes the lifting rod 501 to rise. The lifting rod 501 drives the second pointer 504 to rise through the driving rod 502 and the third connecting rod 503, so as to detect the gas pressure in the pipe body 101 through the scale on the side of the scale plate 505. At the same time, the third connecting rod 503 drives the vertical rod 506 to rise. The vertical rod 506 drives the piston shaft 508 to rise through the fourth connecting rod 507. When the piston at the lower part of the piston shaft 508 crosses the air release pipe 509, the gas is discharged through the air release pipe 509. When the gas pressure weakens to the safe range, the lifting plate 515 descends. At the same time, the pressing block 312 opens the air inlet pipe 103 and the air outlet pipe 102.

[0032] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. An electromagnetic flowmeter for measuring gas flow rate, comprising a mounting mechanism (1), characterized in that: The electromagnetic flowmeter for measuring gas flow also includes a measuring mechanism (2), a switching mechanism (3), a mounting cylinder (4) and a pressure relief mechanism (5). The mounting mechanism (1) includes a pipe body (101) and a mounting component, and the mounting component is connected to the pipe body (101). The measuring mechanism (2) includes a first mounting bracket (201) and a rotational speed detection component, and the rotational speed detection component is connected to the pipe body (101). The first mounting bracket (201) is connected to the mounting component; The switching mechanism (3) includes a driving shaft (301), a pressing block (312), a switching component and a transmission component. The driving shaft (301) is installed on the outer surface of the pipe body (101), the driving shaft (301) is connected to the transmission component, the transmission component is connected to the pressing block (312), the transmission component is connected to the switching component, and the pressing block (312) is installed on the side of the pipe body (101). The mounting cylinder (4) is installed on the pipe body (101). The pressure relief mechanism (5) includes a lifting rod (501), a ventilation cylinder (510), a pressure measuring component and a pressure relief component. A part of the lifting rod (501) is installed inside the mounting cylinder (4), and the part of the lifting rod (501) installed outside the mounting cylinder (4) is connected to the pressure measuring component. The pressure measuring component is connected to the pipe body (101), the pressure measuring component is connected to the pressure relief component, and the pressure relief component is connected to the pipe body (101).

2. The electromagnetic flowmeter for measuring gas flow according to claim 1, wherein: The mounting component includes an air outlet pipe (102) and an air inlet pipe (103). The air outlet pipe (102) and the air inlet pipe (103) are installed on two end faces of the pipe body (101). The outer surface of the pipe body (101) is provided with a first mounting hole (104), a second mounting hole (105), a third mounting hole (106) and a fourth mounting hole (107). The axial directions of the first mounting hole (104) and the second mounting hole (105) are parallel, the axial directions of the third mounting hole (106) and the fourth mounting hole (107) are parallel, the axial direction of the first mounting hole (104) and the third mounting hole (106) are perpendicular, and the axial directions of the pipe body (101), the first mounting hole (104) and the third mounting hole (106) are perpendicular to each other. The mounting cylinder (4) is installed on the inner wall of the first mounting hole (104), and the ventilation cylinder (510) is installed on the inner wall of the second mounting hole (105).

3. The electromagnetic flowmeter for measuring gas flow according to claim 2, wherein: The pressure measuring component includes a rotating shaft (205). The rotating shaft (205) is rotatably installed on the inner wall of the third mounting hole (106). A part of the rotating shaft (205) extends into the pipe body (101). A rotating rod (204) is fixedly installed on the outer surface of the rotating shaft (205) extending into the pipe body (101). A detection head (206) is fixedly installed on the outer surface of the rotating shaft (205) that does not extend into the pipe body (101). The measuring mechanism (2) also includes a first mounting bracket (201) and a second mounting bracket (208). The air inlet pipe (103) is fixedly installed on the first mounting bracket (201), the air outlet pipe (102) is fixedly installed on the second mounting bracket (208). An installation rod (202) is fixedly installed on the side of the first mounting bracket (201), and a rotation measuring instrument (203) is fixedly installed on the side of the installation rod (202).

4. An electromagnetic flowmeter for measuring gas flow according to claim 2, characterized in that: There are two sets of transmission components. Each set of transmission components includes a driving shaft (301). The driving shaft (301) is rotatably installed on the inner wall of the fourth mounting hole (107). A first spring (305) is wound around the outer surface of the driving shaft (301). One end of the first spring (305) is fixedly installed on the outer surface of the driving shaft (301), and the other end of the first spring (305) is fixedly installed on the outer surface of the pipe body (101). A part of the driving shaft (301) extends into the interior of the pipe body (101). A rotating fan blade (304) is fixedly installed on the outer surface of the part of the driving shaft (301) extending into the interior of the pipe body (101). A rotating fan blade (304) is fixedly installed on the outer surface of the part of the driving shaft (301) extending into the interior of the pipe body (101). A turntable (303) is fixedly installed on the outer surface of the part of the driving shaft (301) that does not extend into the interior of the pipe body (101). A scale is provided on the side surface of the turntable (303). A turntable (303) is also rotatably installed on the outer surface of the part of the driving shaft (301) that does not extend into the interior of the pipe body (101). The turntable (303) is located on the side surface of the turntable (303) away from the pipe body (101). A third mounting bracket (209) is rotatably installed on the outer surface of the driving shaft (301). The first pointer (302) is fixedly connected to the third mounting bracket (209). An intermediate plate (207) is fixedly installed on the side surface of the third mounting bracket (209). The intermediate plate (207) is fixedly installed between the first mounting bracket (201) and the second mounting bracket (208).

5. An electromagnetic flowmeter for measuring gas flow rate according to claim 4, characterized in that: There are two sets of switch components. The two sets of switch components are symmetrically installed on the two end faces of the pipe body (101). Each set of switch components includes a first connecting rod (306) and a fixed sleeve (311). The two first connecting rods (306) are respectively rotatably connected to a turntable (303). The two fixed sleeves (311) are symmetrically fixedly installed on the two end faces of the pipe body (101). The two fixed sleeves (311) are coaxial with the air outlet pipe (102) and the air inlet pipe (103) respectively. A limiting track (309) is fixedly installed on each fixed sleeve (311). A slider (310) is slidably installed on the side surface of the limiting track (309). A pressing block (312) is fixedly installed at the lower part of the slider (310). The lower part of the pressing block (312) is semicircular. A driving plate (308) is fixedly installed on the side surface of the slider (310). A second connecting rod (307) is fixedly installed on the side surface of the driving plate (308). The two second connecting rods (307) are respectively rotatably connected to a first connecting rod (306).

6. An electromagnetic flowmeter for measuring gas flow according to claim 4, characterized in that: The mounting cylinder (4) is fixedly mounted on the inner wall of the first mounting hole (104). The pressure measuring assembly is provided with a lifting plate (515). The lifting plate (515) is slidably mounted on the inner wall of the mounting cylinder (4). A fixing plate (512) is also fixedly mounted on the inner wall of the mounting cylinder (4). The fixing plate (512) is located above the lifting plate (515). A sliding shaft (513) is fixedly mounted on the lifting plate (515). The sliding shaft (513) is slidably connected with the fixing plate (512). A second spring (514) is wound around the outer surface of the sliding shaft (513). One end of the second spring (514) is fixedly mounted on the outer surface of the sliding shaft (513), and the other end of the second spring (514) is fixedly mounted on the fixing plate (512). The fixing plate (512) is slidably connected with the lifting rod (501).

7. An electromagnetic flowmeter for measuring gas flow rate according to claim 6, characterized in that: The lower part of the lifting rod (501) is hemispherical. The lower part of the lifting rod (501) is tangent to the lifting plate (515). A third spring (516) is wound around the outer surface of the lifting plate (515). One end of the third spring (516) is fixedly mounted on the lifting rod (501), and the other end of the third spring (516) is fixedly mounted on the fixing plate (512). A driving rod (502) and a third connecting rod (503) are fixedly mounted on the lifting rod (501). A chute (511) is provided on the outer surface of the lifting rod (501). Both the driving rod (502) and the third connecting rod (503) are slidably mounted on the inner wall of the chute (511). A second pointer (504) is fixedly mounted on the side of the driving rod (502). A scale plate (505) is slidably mounted on the side of the second pointer (504). Scales are provided on the side of the scale plate (505).

8. An electromagnetic flowmeter for measuring gas flow rate according to claim 7, characterized in that: A vertical rod (506) is fixedly mounted on the third connecting rod (503). A fourth connecting rod (507) is fixedly mounted on the outer surface of the vertical rod (506). The pressure relief assembly includes a piston shaft (508). The piston shaft (508) is fixedly mounted on the lower part of the fourth connecting rod (507). A piston is provided at the lower part of the piston shaft (508). The piston at the lower part of the piston shaft (508) is slidably connected with the ventilation cylinder (510). An air release pipe (509) is fixedly mounted on the outer surface of the ventilation cylinder (510). The air release pipe (509) is communicated with the inside of the ventilation cylinder (510). In the initial state, the piston at the lower part of the piston shaft (508) is located below the air release pipe (509).

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