A method and device for detecting a gas in a limited space

Abstract

The application belongs to the technical field of gas detection, and discloses a limited space operation gas detection method, and the specific steps are as follows: S1, the detection device is checked and calibrated to ensure normal operation of the device. The application also discloses a limited space operation gas detection device, which comprises: a shell mechanism, an insulating rope is hung on the shell mechanism; a communication mechanism is arranged in the shell mechanism, and the shell mechanism is used for opening and closing the contact of the sensor with the outside air. The application drives the movable mechanism as a whole to move downward through the electric telescopic rod, so as to drive the communication mechanism to open the channel of the sensor with the outside. With the movable mechanism moving away from the communication mechanism, the outside gas is sucked into the first shell. When the movable mechanism moves to the maximum value, the communication mechanism is closed, and at this time, the gas in the communication mechanism is in a relatively static state, which is convenient for detection and prevents errors caused by gas flow.

Description

Technical Field

[0001] This invention belongs to the field of gas detection technology, specifically a gas detection method and device for confined space operations. Background Technology

[0002] A confined space refers to a closed or partially closed space with restricted access but accessible to personnel. It is not designed as a fixed workplace, has poor ventilation, and is prone to the accumulation of toxic, harmful, flammable, or explosive substances, or insufficient oxygen content. When working in a confined space, the gas content must be monitored using a professional gas detector before and during the operation, adhering to the core principle of "detect first, then ventilate, then work."

[0003] When detecting air in a confined space, the detection device is typically suspended at different depths within the space using ropes. After maintaining the device stable for several minutes, stable data can be obtained. This requires that the detection device not adhere to the inner wall of the confined space, and that the device not be allowed to shake. Shaking will cause airflow disturbance, leading to gas mixing within the confined space and affecting detection accuracy. Furthermore, the air in a confined space contains many impurities that easily adhere to the sensor, further impacting detection accuracy. Therefore, improvements are made to address these issues. Summary of the Invention

[0004] To address the problem mentioned in the background art that impurities in a confined space can adhere to the sensor, the present invention provides a method and apparatus for detecting gases in confined spaces.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a gas detection method for confined space operations, the specific steps of which are as follows:

[0006] S1. Inspect and calibrate the detection device to ensure its normal operation;

[0007] S2. Determine the detection points based on the depth within the confined space, namely, 50 centimeters below the entrance of the confined space, halfway through the depth of the confined space, and 30 centimeters above the bottom of the confined space, to ensure coverage of areas where gases of different densities accumulate.

[0008] S3. Suspend the insulating rope on the detection device and slowly lower it to the point in the confined space;

[0009] S4. Stay at the measurement point for three to five minutes and record the data after it has stabilized.

[0010] This invention also provides the following technical solution: a confined space operation gas detection device, comprising:

[0011] The housing mechanism is suspended by an insulating rope.

[0012] A communication mechanism is provided inside the housing mechanism, which is used to open and close the sensor's contact with the outside air;

[0013] An active mechanism is disposed inside the housing mechanism and below the communication mechanism. The active mechanism is used to carry the sensor and to expel or draw gas from the confined space into the housing mechanism by moving up and down.

[0014] An electric telescopic rod is installed inside the housing mechanism and located below the movable mechanism. The electric telescopic rod is used to drive the movable mechanism to move up and down.

[0015] Preferably, the housing mechanism includes a first housing, a filter screen, and a second housing, the first housing and the second housing being detachably connected, and the filter screen being disposed on the top of the first housing.

[0016] Preferably, the communication mechanism includes a first baffle assembly, a second baffle assembly, a second pawl, and a cleaning assembly. The first baffle assembly and the second baffle assembly are both horizontally rotatably connected to the inside of the first housing and are in close contact with each other. The second pawl is arranged in a ring on the inner wall of the first housing and is elastically rotatably connected to the first housing through a torsion spring. The cleaning assembly is disposed inside the second baffle assembly.

[0017] Preferably, the first baffle assembly includes a first plate, a first connecting plate, a first ratchet, and a second ratchet. The first connecting plate is annularly mounted in the middle of the first plate, the first ratchet is mounted at the bottom of the first plate, and the second ratchet is mounted on the outer side of the first plate. The second ratchet is restricted by a second pawl to rotate only in one direction.

[0018] Preferably, the second baffle assembly includes a second plate, an annular groove, a first pawl, a spiral groove, and a second connecting plate. The annular groove is formed on the outer edge of the top of the second plate. The first pawl is arranged in a ring inside the annular groove and is elastically rotatably connected to the second plate by a torsion spring. The spiral groove is formed in a ring on the outer side of the second plate. The second connecting plate is installed in a ring in the middle of the second plate. The first pawl elastically abuts against the first ratchet. In the initial state, the second connecting plate is offset from the first connecting plate.

[0019] Preferably, the cleaning assembly includes a cleaning plate and a first spring, wherein the cleaning plate is elastically connected to and slides inside the second plate via the first spring.

[0020] Preferably, the movable mechanism includes a first movable plate, a second movable plate, a bracket, a positioning plate, and a second spring. The bracket is fixedly installed at the bottom of the first movable plate. The second movable plate is elastically slidably connected to the first movable plate through the second spring. The positioning plate is installed on both sides of the first movable plate and slides up and down inside the first housing. The bottom of the bracket is connected to the output shaft of the electric telescopic rod. One end of the positioning plate is provided with a slider adapted to the spiral groove. When the first movable plate moves up and down, it can drive the second baffle assembly to rotate through the positioning plate, and the maximum rotation angle of the second baffle assembly is 180 degrees.

[0021] Preferably, the surface of the second movable disc is provided with a cross-shaped groove, the width of which is smaller than the width of the cleaning plate, and a sensor is provided in the included angle area of ​​the cross-shaped groove on the surface of the second movable disc.

[0022] Preferably, a baffle is provided at the lower end of the interior of the first housing, the baffle being a hollow frustum, and ventilation holes are provided on the surface of the second housing.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] This invention uses an electric telescopic rod to drive the entire movable mechanism downward, thereby causing the connecting mechanism to open the channel between the sensor and the outside world. As the movable mechanism moves away from the connecting mechanism, outside gas is drawn into the first housing. When the movable mechanism moves to its maximum value, the connecting mechanism closes. At this time, the gas inside the connecting mechanism is in a relatively static state, which facilitates detection and prevents errors caused by gas flow.

[0025] When the gas inside the first housing is discharged after detection, the cleaning plate is in contact with the surface of the second movable disk. This can wipe the sensor on the surface of the second movable disk. The bottom of the cleaning plate can be made of a flexible, insulating and fireproof material to prevent scratches on the sensor and further prevent the residue of impurities. The cleaning plate can be completely retracted into the second plate body, which can also ensure the complete discharge of the gas inside the first housing after detection.

[0026] The present invention moves the entire movable mechanism upward, and the gas inside the first housing pushes the second movable disk under pressure, creating a gap between the second movable disk and the first movable disk. The gas is discharged through this gap. The cross-shaped groove on the surface of the second movable disk can store the impurities wiped off by the cleaning plate and be discharged through the second housing with the airflow. The porous design reduces the disturbance to the surrounding gas during exhaust. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention;

[0028] Figure 2This is a cross-sectional view of the structure of the first housing of the present invention;

[0029] Figure 3 For the present invention Figure 2 Enlarged view of A in the middle;

[0030] Figure 4 This is a detailed structural diagram of the connecting mechanism of the present invention;

[0031] Figure 5 This is a detailed structural diagram of the first baffle assembly of the present invention;

[0032] Figure 6 This is a detailed structural diagram of the cleaning component of the present invention;

[0033] Figure 7 This is a structural separation diagram of the active mechanism of the present invention;

[0034] Figure 8 This is a schematic diagram of the internal structure of the second housing of the present invention.

[0035] In the diagram: 100, housing mechanism; 110, first housing; 120, filter screen; 130, second housing; 101, baffle; 200, connecting mechanism; 210, first baffle assembly; 211, first plate; 212, first connecting plate; 213, first ratchet; 214, second ratchet; 220, second baffle assembly; 221, second plate; 222, annular groove; 223, first pawl; 224, spiral groove; 225, second connecting plate; 230, second pawl; 240, cleaning assembly; 241, cleaning plate; 242, first spring; 300, movable mechanism; 310, first movable disc; 320, second movable disc; 330, bracket; 340, positioning plate; 350, second spring; 400, electric telescopic rod. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] This invention provides a gas detection method for confined space operations, the specific steps of which are as follows:

[0038] S1. Inspect and calibrate the detection device to ensure its normal operation;

[0039] S2. Determine the detection points based on the depth within the confined space, namely, 50 centimeters below the entrance of the confined space, halfway through the depth of the confined space, and 30 centimeters above the bottom of the confined space, to ensure coverage of areas where gases of different densities accumulate.

[0040] S3. Suspend the insulating rope on the detection device and slowly lower it to the point in the confined space;

[0041] S4. Stay at the measurement point for three to five minutes and record the data after it has stabilized.

[0042] like Figures 1 to 8 As shown, the present invention provides a gas detection device for confined space operations, comprising:

[0043] The housing mechanism 100 is suspended by an insulating rope.

[0044] A connecting mechanism 200 is disposed inside the housing mechanism 100, which is used to open and close the sensor's contact with the outside air.

[0045] The movable mechanism 300 is located inside the housing mechanism 100 and below the connecting mechanism 200. The movable mechanism 300 is used to carry the sensor and to discharge or draw gas from the confined space into the housing mechanism 100 by moving up and down.

[0046] An electric telescopic rod 400 is disposed inside the housing mechanism 100 and located below the movable mechanism 300. The electric telescopic rod 400 is used to drive the movable mechanism 300 to move up and down.

[0047] The above scheme is adopted: the electric telescopic rod 400 drives the movable mechanism 300 to move down as a whole, thereby driving the connecting mechanism 200 to open the channel between the sensor and the outside world. As the movable mechanism 300 moves away from the connecting mechanism 200, the outside gas is drawn into the first housing 110. When the movable mechanism 300 moves to the maximum value, the connecting mechanism 200 is closed. At this time, the gas inside the connecting mechanism 200 is in a relatively static state, which facilitates detection and prevents errors caused by gas flow.

[0048] like Figures 1 to 6As shown, the housing mechanism 100 includes a first housing 110, a filter screen 120, and a second housing 130. The first housing 110 and the second housing 130 are detachably connected. The filter screen 120 is disposed on the top of the first housing 110. The communication mechanism 200 includes a first baffle assembly 210, a second baffle assembly 220, a second pawl 230, and a cleaning assembly 240. The first baffle assembly 210 and the second baffle assembly 220 are both horizontally rotatably connected to the inside of the first housing 110 and are in close contact with each other. The second pawl 230 is annularly disposed on the inner wall of the first housing 110 and is elastically rotatably connected to the first housing 110 by a torsion spring. The cleaning assembly 240 is disposed inside the second baffle assembly 220. The first baffle assembly 210 includes a first plate 211, a first connecting plate 212, a first ratchet 213, and a second ratchet 214. The first connecting plate 212 is annularly disposed on the first baffle assembly 220. The first ratchet 213 is installed at the bottom of the first plate 211, and the second ratchet 214 is installed on the outside of the first plate 211. The second ratchet 214 is restricted to rotating in only one direction by the second pawl 230. The second baffle assembly 220 includes a second plate 221, an annular groove 222, a first pawl 223, a spiral groove 224, and a second connecting plate 225. The annular groove 222 is opened at the outer edge of the top of the second plate 221. The first pawl 223 is arranged in an annular shape inside the annular groove 222. The first pawl 223 is elastically rotatably connected to the second plate 221 by a torsion spring. The spiral groove 224 is opened in an annular shape on the outside of the second plate 221. The second connecting plate 225 is installed in an annular shape at the middle of the second plate 221. The first pawl 223 and the first ratchet 213 elastically abut against each other. In the initial state, the second connecting plate 225 is offset from the first connecting plate 212.

[0049] Using the above scheme: the filter 120 can pre-filter the gas in the confined space, reducing the content of impurities in the gas. In the top projection view, when the second plate 221 rotates clockwise, the first ratchet 213 and the first pawl 223 are locked, while the second ratchet 214 and the second pawl 230 are not locked. At this time, the rotation of the second plate 221 can synchronously drive the first baffle assembly 210 to rotate. When the second plate 221 rotates counterclockwise, the second ratchet 214 and the second pawl 230 are locked, while the first ratchet 213 and the first pawl 223 are not locked. At this time, the second plate 221 can only rotate on its own.

[0050] like Figure 6 As shown, the cleaning assembly 240 includes a cleaning plate 241 and a first spring 242. The cleaning plate 241 is elastically connected to and slides inside the second plate 221 via the first spring 242.

[0051] The above solution is adopted as follows: During the process of the moving mechanism 300 moving upward inside the first housing 110, that is, when the gas inside the first housing 110 is discharged after detection, the cleaning plate 241 is in contact with the surface of the second moving disk 320. This can wipe the sensor on the surface of the second moving disk 320. The bottom of the cleaning plate 241 can be made of a flexible, insulating and fireproof material to prevent scratching the sensor. In addition, the cleaning plate 241 can be completely retracted into the second plate 221, which can also ensure the complete discharge of the gas inside the first housing 110 after detection.

[0052] like Figures 4 to 7 As shown, the movable mechanism 300 includes a first movable disk 310, a second movable disk 320, a bracket 330, a positioning plate 340, and a second spring 350. The bracket 330 is fixedly installed at the bottom of the first movable disk 310. The second movable disk 320 is elastically slidably connected to the first movable disk 310 through the second spring 350. The positioning plate 340 is installed on both sides of the first movable disk 310 and slides up and down inside the first housing 110. The bottom of the bracket 330 is connected to the output shaft of the electric telescopic rod 400. One end of the positioning plate 340 is provided with a slider that matches the spiral groove 224. When the first movable disk 310 moves up and down, it can drive the second baffle assembly 220 to rotate through the positioning plate 340, and the maximum rotation angle of the second baffle assembly 220 is 180 degrees. A cross-shaped groove is opened on the surface of the second movable disk 320. The width of the cross-shaped groove is smaller than the width of the cleaning plate 241. A sensor is provided in the included angle area of ​​the cross-shaped groove on the surface of the second movable disk 320.

[0053] The above scheme is adopted: the movable mechanism 300 is driven up and down by the electric telescopic rod 400. When the movable mechanism 300 moves down, the cooperation between the positioning plate 340 and the spiral groove 224 can drive the second plate 221 to rotate, thereby intermittently opening the contact channel between the sensor and the external gas. When the movable mechanism 300 moves up, the positioning plate 340 drives the second plate 221 to rotate in the opposite direction. The cleaning plate 241 gradually sticks to the second movable disk 320 and rotates on the surface of the second movable disk 320 to form a wiping action, further preventing the residue of impurities. The cross-shaped groove opened on the surface of the second movable disk 320 can store the impurities wiped off by the cleaning plate 241 and be discharged with the airflow.

[0054] It is worth noting that the sensors can be configured in different types. Electrochemical sensors generate a current proportional to the gas concentration through a redox reaction between the gas and the electrodes inside the sensor, which is used to detect hydrogen sulfide and carbon monoxide. Catalytic combustion sensors generate a current by burning combustible gas on the sensor surface, consuming oxygen and producing a current whose magnitude reflects the gas concentration. Infrared sensors detect carbon dioxide and oxygen by detecting the concentration of the target gas when infrared light of a specific wavelength passes through it and is absorbed by the target gas when the infrared light is attenuated.

[0055] An alarm corresponding to the sensor can also be set. When the sensor detects that the harmful gas exceeds the threshold, the alarm will sound to warn the operator. Two sets of alarms can be set, one set is located outside the first housing 110, and the other set is located outside the confined space, specifically at the operator's location, to ensure that the warning can be perceived by the operator as soon as possible.

[0056] like Figure 8 As shown, a baffle 101 is provided at the lower end of the interior of the first housing 110. The baffle 101 is a hollow frustum. Ventilation holes are provided on the surface of the second housing 130.

[0057] The above solution is adopted: the design of the baffle 101 can prevent the backflow of impurities, and the gas passing through the gap between the second movable disk 320 and the first movable disk 310 is discharged through the exhaust hole on the surface of the second housing 130. The porous design reduces the disturbance to the surrounding gas during exhaust.

[0058] It is worth noting that this application is applicable to spaces such as manually excavated bored piles and fire water tanks.

[0059] Working principle and usage process of this invention:

[0060] In use, the insulating rope is first suspended on the first housing 110 and slowly lowered to the point in the confined space. After reaching the position, the stability of the detection device is ensured. Then, the electric telescopic rod 400 drives the movable mechanism 300 to move down inside the first housing 110. During the downward movement, the positioning plate 340 drives the second plate 221 to rotate counterclockwise in the top projection view through the cooperation with the spiral groove 224. At this time, the second ratchet 214 and the second pawl 230 are locked, while the first ratchet 213 and the first pawl 223 are not locked. The second plate 221 can only rotate on its own. The first connecting plate 212 and the second connecting plate 225 are connected, drawing external gas into the first housing 110. When the movable mechanism 300 moves down to the maximum position, the first connecting plate 212 and the second connecting plate 225 are misaligned and not connected. At this time, the sensor detects the harmful gas components.

[0061] After the test is completed, the electric telescopic rod 400 drives the movable mechanism 300 to move upward as a whole, and the second plate 221 rotates clockwise. The first ratchet 213 and the first pawl 223 are locked, while the second ratchet 214 and the second pawl 230 are not locked. At this time, the rotation of the second plate 221 can synchronously drive the first baffle assembly 210 to rotate. The first connecting plate 212 and the second connecting plate 225 remain staggered and not connected. The gas inside the first housing 110 pushes the second movable disk 320 under pressure, creating a gap between the second movable disk 320 and the first movable disk 310. The gas is discharged through this gap. At the same time, the cleaning plate 241 gradually presses against the second movable disk 320 and rotates on the surface of the second movable disk 320 to form a wiping action, further preventing the residue of impurities. The cross-shaped groove on the surface of the second movable disk 320 can store the impurities wiped off by the cleaning plate 241 and be discharged with the airflow.

[0062] After the test at this point is completed, the insulating rope is lowered to test another point.

[0063] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0064] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A gas detection device for confined space operations, characterized in that, include: Housing mechanism (100), with an insulating rope suspended from the housing mechanism (100); A connecting mechanism (200) is disposed inside the housing mechanism (100), the housing mechanism (100) being used to open and close the sensor's contact with the outside air; An active mechanism (300) is disposed inside the housing mechanism (100) and below the connecting mechanism (200). The active mechanism (300) is used to carry the sensor and to discharge or draw gas from the confined space into the housing mechanism (100) by moving up and down. An electric telescopic rod (400) is disposed inside the housing mechanism (100) and located below the movable mechanism (300). The electric telescopic rod (400) is used to drive the movable mechanism (300) to move up and down. The housing mechanism (100) includes a first housing (110), a filter (120), and a second housing (130). The communication mechanism (200) includes a first baffle assembly (210), a second baffle assembly (220), a second pawl (230), and a cleaning assembly (240). The first baffle assembly (210) and the second baffle assembly (220) are both horizontally rotatably connected to the inside of the first housing (110) and are in close contact with each other. The second pawl (230) is arranged in a ring on the inner wall of the first housing (110). The second pawl (230) is elastically rotatably connected to the first housing (110) through a torsion spring. The cleaning assembly (240) is disposed inside the second baffle assembly (220). The first baffle assembly (210) includes a first plate (211), a first connecting plate (212), a first ratchet (213), and a second ratchet (214). The first connecting plate (212) is annularly mounted in the middle of the first plate (211). The first ratchet (213) is mounted at the bottom of the first plate (211). The second ratchet (214) is mounted on the outside of the first plate (211). The second ratchet (214) is restricted by the second pawl (230) to rotate only in one direction. The second baffle assembly (220) includes a second plate (221), an annular groove (222), a first pawl (223), a spiral groove (224), and a second connecting plate (225). The annular groove (222) is opened on the outer edge of the top of the second plate (221). The first pawl (223) is arranged in an annular shape inside the annular groove (222). The first pawl (223) is elastically rotatably connected to the second plate (221) through a torsion spring. The spiral groove (224) is opened in an annular shape on the outer side of the second plate (221). The second connecting plate (225) is installed in an annular shape in the middle of the second plate (221). The first pawl (223) elastically abuts against the first ratchet (213). In the initial state, the second connecting plate (225) is offset from the first connecting plate (212). The movable mechanism (300) includes a first movable plate (310), a second movable plate (320), a bracket (330), a positioning plate (340), and a second spring (350); The bracket (330) is fixedly installed at the bottom of the first movable plate (310). The second movable plate (320) is elastically slidably connected to the first movable plate (310) through the second spring (350). The positioning plate (340) is installed on both sides of the first movable plate (310) and slides up and down inside the first housing (110). The bottom of the bracket (330) is connected to the output shaft of the electric telescopic rod (400). One end of the positioning plate (340) is provided with a slider that matches the spiral groove (224). When the first movable plate (310) moves up and down, it can drive the second baffle assembly (220) to rotate through the positioning plate (340), and the maximum rotation angle of the second baffle assembly (220) is 180 degrees. The surface of the second movable disc (320) is provided with a cross-shaped groove, the width of which is smaller than the width of the cleaning plate (241); A sensor is provided in the included area of ​​the cross-shaped groove on the surface of the second movable disk (320); The surface of the second housing (130) is provided with ventilation holes.

2. The confined space operation gas detection device according to claim 1, characterized in that: The first housing (110) and the second housing (130) are detachably connected, and the filter (120) is disposed on the top of the first housing (110).

3. The confined space operation gas detection device according to claim 1, characterized in that: The cleaning assembly (240) includes a cleaning plate (241) and a first spring (242), wherein the cleaning plate (241) is elastically connected to and slides inside the second plate (221) via the first spring (242).

4. The confined space operation gas detection device according to claim 2, characterized in that: A baffle (101) is provided at the lower end of the interior of the first housing (110), and the baffle (101) is a hollow frustum.

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