Trace chemiluminescence nitrogen detector

Abstract

The utility model discloses a trace chemiluminescence nitrogen detector in a nitrogen content detection technology, and aims to solve the problems of low detection sensitivity and incapability of meeting the requirement of trace analysis due to low luminous efficiency and serious light quenching effect of a chemiluminescence nitrogen detector in the prior art. The light-emitting chamber comprises a light-emitting chamber body and a photomultiplier, the light-emitting chamber body is detachably connected with the photomultiplier through a connecting block, a nitrogen light-emitting chamber is formed in the side, close to the connecting block, of the outer wall of the light-emitting chamber body, a light filter used for sealing the nitrogen light-emitting chamber is arranged on the outer wall of the light-emitting chamber body, and a convex lens is arranged in the connecting block in a sleeved mode; the nitrogen light-emitting chamber is controlled by the vacuum pump to reach a certain vacuum degree, so that the air pressure in the nitrogen light-emitting chamber is close to a vacuum state, the quenching effect of light is reduced, and the detection sensitivity is improved; the convex lens gathers the originally scattered light to the photomultiplier tube, so that the total amount of light emitted to the surface of the photomultiplier tube is increased.

Description

Technical Field

[0001] The utility model relates to a trace chemiluminescent nitrogen detector, belonging to the technical field of nitrogen content detection. Background Art

[0002] Nitrogen content is a key testing item in petroleum and chemical products. Nitrogen content not only affects product quality but can also poison catalysts during the production process, increasing production costs. In atmospheric environmental monitoring, nitrogen compound content is a key indicator of atmospheric quality. In summary, the necessity of nitrogen content testing is reflected in multiple fields, from oil quality control to environmental protection and scientific research. Accurate nitrogen content testing is essential.

[0003] Currently, most methods for detecting nitrogen content use chemiluminescence. This method is simple in principle, does not cause secondary pollution during the detection process, and can be used to detect nitrogen content in solid, liquid, and gaseous samples. The sample undergoes a high-temperature cracking reaction, converting various forms of nitrogen into nitric oxide gas. Nitric oxide gas and ozone gas are simultaneously introduced into a nitrogen luminescence chamber through two different pipes. Nitric oxide and ozone react chemically to produce high-energy nitrogen dioxide. High-energy nitrogen dioxide is unstable and releases energy in the form of light when transitioning to a lower energy state. The intensity of this light is detected by a photomultiplier tube. Since the intensity of the light is proportional to the nitric oxide content, the nitrogen content can be calculated.

[0004] Existing chemiluminescent nitrogen detectors have low luminescence efficiency and severe light quenching effect, resulting in low detection sensitivity, which cannot meet the requirements of trace analysis and affects the working performance of the detector. Utility Model Content

[0005] The purpose of the utility model is to overcome the deficiencies in the prior art and provide a trace chemiluminescent nitrogen detector to solve the problems of low luminescence efficiency and severe light quenching effect of the existing chemiluminescent nitrogen detector, which leads to low detection sensitivity and cannot meet the requirements of trace analysis.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The utility model provides a trace chemiluminescent nitrogen detector, comprising a luminescence chamber body and a photomultiplier tube, wherein the luminescence chamber body is detachably connected to the photomultiplier tube via a connecting block, a nitrogen luminescence chamber is provided on the outer wall of the luminescence chamber body close to the connecting block, a filter is provided on the outer wall of the luminescence chamber body for sealing the nitrogen luminescence chamber, a convex lens is provided in the connecting block, and the photomultiplier tube, the convex lens and the nitrogen luminescence chamber are coaxially arranged;

[0008] An air outlet and two air inlet holes are provided on the outer wall of the luminous chamber body. One end of the air outlet and one end of the two air inlet holes are both connected to the nitrogen luminous chamber, and the other end of the air outlet is connected to the vacuum pump.

[0009] Furthermore, a first sealing block is provided in one of the air inlet holes, and a nitric oxide inlet pipe is sleeved in the first sealing block. One end of the nitric oxide inlet pipe passes through the air inlet hole and extends to the inside of the nitrogen light-emitting chamber, and the other end of the nitric oxide inlet pipe extends to the outside of the light-emitting chamber body.

[0010] Furthermore, a second sealing block is provided in the other air inlet hole, and an ozone inlet pipe is sleeved in the second sealing block. One end of the ozone inlet pipe passes through the air inlet hole and extends to the inside of the nitrogen luminous chamber, and the other end of the ozone inlet pipe extends to the outside of the luminous chamber body.

[0011] Furthermore, the nitric oxide inlet pipe and the ozone inlet pipe are both capillaries.

[0012] Furthermore, a third sealing block is provided in the air outlet, a connecting pipe is sleeved in the third sealing block, and one end of the connecting pipe extends to the outside of the light-emitting chamber body and is connected to the vacuum pump.

[0013] Furthermore, the convex lens is a compound lens.

[0014] Furthermore, the connecting block is detachably connected to the photomultiplier tube via bolts.

[0015] Furthermore, the photomultiplier tube is provided with a first support block at one end away from the light-emitting chamber body, and the outer wall of the light-emitting chamber body is provided with a second support block. The outer walls of the first support block and the second support block are covered with the same light-proof sealing cover, and the light-proof sealing cover is located outside the photomultiplier tube.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. This trace chemiluminescent nitrogen detector uses a vacuum pump to extract the reaction exhaust from the nitrogen luminescence chamber, thereby controlling the nitrogen luminescence chamber to reach a certain vacuum level, making the air pressure in the nitrogen luminescence chamber close to a vacuum state, reducing the light quenching effect and improving the detection sensitivity. The present application adds a convex lens between the nitrogen luminescence chamber and the photomultiplier tube to focus the originally scattered light onto the photomultiplier tube, increasing the total amount of light emitted to the surface of the photomultiplier tube, and further improving the detection sensitivity.

[0018] 2. The nitric oxide inlet pipe and the ozone inlet pipe of the utility model are both capillaries, which control the flow of nitric oxide gas and ozone gas entering the nitrogen luminescence chamber, avoid leakage in the nitrogen luminescence chamber, and ensure the stability of the vacuum pump during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The figure is a schematic diagram of a main cross-section of a trace chemiluminescent nitrogen detector provided according to an embodiment of the present utility model.

[0020] In the figure: 1. Light-emitting chamber body; 2. Photomultiplier tube; 3. Connecting block; 4. Nitrogen light-emitting chamber; 5. Filter; 6. Convex lens; 7. Air outlet; 8. Air inlet; 9. Vacuum pump; 10. Nitric oxide inlet pipe; 11. Ozone inlet pipe; 12. Connecting pipe; 13. Bolt; 14. First support block; 15. Second support block; 16. Light-proof sealed outer cover. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention.

[0022] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0023] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0024] like Figure 1 As shown, the utility model provides a trace chemiluminescent nitrogen detector, comprising a luminescence chamber body 1 and a photomultiplier tube 2, wherein the luminescence chamber body 1 is detachably connected to the photomultiplier tube 2 via a connecting block 3, a nitrogen luminescence chamber 4 is provided on the outer wall of the luminescence chamber body 1 close to the connecting block 3, a filter 5 is provided on the outer wall of the luminescence chamber body 1 for sealing the nitrogen luminescence chamber 4, a convex lens 6 is provided inside the connecting block 3, and the photomultiplier tube 2, the convex lens 6 and the nitrogen luminescence chamber 4 are coaxially arranged; an air outlet 7 and two air inlet holes 8 are provided on the outer wall of the luminescence chamber body 1, one end of the air outlet 7 and one end of the two air inlet holes 8 are both connected to the nitrogen luminescence chamber 4, and the other end of the air outlet 7 is connected to a vacuum pump 9.

[0025] Specifically, during operation, the nitrogen compound is converted into nitric oxide gas after pretreatment, and the nitric oxide gas is input into the interior of the nitrogen luminescent chamber 4 through one of the air inlet holes 8, and the ozone gas is input into the interior of the nitrogen luminescent chamber 4 through the other air inlet hole 8, so that the nitric oxide gas and the ozone gas undergo a chemiluminescence reaction in the nitrogen luminescent chamber 4, and the emitted light is filtered by the filter 5 and focused by the convex lens 6, and then irradiated onto the photomultiplier tube 2. The photomultiplier tube 2 converts the light signal into a corresponding electrical signal and sends it to the secondary instrument for processing. Because the light signal is proportional to the nitrogen content, the concentration of the nitrogen content can be calculated by measuring the size of the electrical signal; during operation, the reaction tail gas is extracted from the nitrogen luminescent chamber 4 by the vacuum pump 9, thereby controlling the nitrogen luminescent chamber 4 to reach a certain vacuum degree, reducing the chemiluminescence quenching effect of nitrogen, and achieving the purpose of improving the detection sensitivity; the present application reduces the volume of the nitrogen luminescent chamber 4, thereby increasing the optical density, reducing the scattering of light, and improving the light intensity; optionally, the convex lens 6 is a composite lens.

[0026] The utility model uses a vacuum pump 9 to extract the reaction tail gas from the nitrogen luminescence chamber 4, thereby controlling the nitrogen luminescence chamber 4 to reach a certain vacuum degree, so that the air pressure in the nitrogen luminescence chamber 4 is close to a vacuum state, reducing the light quenching effect, improving the detection sensitivity, meeting the requirements of trace analysis, and the minimum detection limit reaches 10ppb; the present application adds a convex lens 6 between the nitrogen luminescence chamber 4 and the photomultiplier tube 2, and the originally scattered light is gathered onto the photomultiplier tube 2, thereby increasing the total amount of light emitted to the surface of the photomultiplier tube 2, and further improving the detection sensitivity.

[0027] In one embodiment, a first sealing block is provided in one of the air inlet holes 8, and a nitric oxide inlet pipe 10 is sleeved in the first sealing block. One end of the nitric oxide inlet pipe 10 passes through the air inlet hole 8 and extends to the interior of the nitrogen luminous chamber 4, and the other end of the nitric oxide inlet pipe 10 extends to the outside of the luminous chamber body 1; a second sealing block is provided in the other air inlet hole 8, and an ozone inlet pipe 11 is sleeved in the second sealing block. One end of the ozone inlet pipe 11 passes through the air inlet hole 8 and extends to the interior of the nitrogen luminous chamber 4, and the other end of the ozone inlet pipe 11 extends to the outside of the luminous chamber body 1; the nitric oxide inlet pipe 10 and the ozone inlet pipe 11 are both capillaries.

[0028] Specifically, the first sealing block supports the nitric oxide inlet pipe 10, and the second sealing block supports the ozone inlet pipe 11. At the same time, the nitric oxide inlet pipe 10 and the ozone inlet pipe 11 are both capillaries, which control the flow of nitric oxide gas and ozone gas into the nitrogen reaction chamber 4, thereby avoiding leakage in the nitrogen luminescence chamber 4; ensuring the stability of the vacuum pump 9 during operation, thereby ensuring that the air pressure in the nitrogen luminescence chamber 4 is close to a vacuum state, and ensuring the stability of the device during operation.

[0029] In one embodiment, a third sealing block is provided in the air outlet 7, and a connecting pipe 12 is sleeved in the third sealing block. One end of the connecting pipe 12 extends to the outside of the light-emitting chamber body 1 and is connected to the vacuum pump 9. The third sealing block supports the connecting pipe 12 to avoid air leakage when the vacuum pump 9 is working, thereby ensuring the stability of the device during operation.

[0030] In one embodiment, the connecting block 3 is detachably connected to the photomultiplier tube 2 via bolts 13, thereby ensuring the convenience of the device and facilitating replacement and maintenance work.

[0031] In one embodiment, the photomultiplier tube 2 is provided with a first support block 14 at one end away from the light-emitting chamber body 1, and the outer wall of the light-emitting chamber body 1 is provided with a second support block 15. The outer walls of the first support block 14 and the second support block 15 are covered with the same light-proof sealing cover 16, and the light-proof sealing cover 16 is located on the outside of the photomultiplier tube 2.

[0032] During use, the light-proof sealed outer cover 16 is installed by cooperating with the first support block 14 and the second support block 15, so that the light-proof sealed outer cover 16 is easy to repair and replace. During operation, the light-proof sealed outer cover 16 protects and shields the photomultiplier tube 2 from light, preventing the external environment from affecting the detection effect of the device, thereby ensuring the detection sensitivity of the device.

[0033] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A trace chemiluminescent nitrogen detector, characterized in that The invention comprises a luminous chamber body (1) and a photomultiplier tube (2), wherein the luminous chamber body (1) is detachably connected to the photomultiplier tube (2) via a connecting block (3), a nitrogen luminous chamber (4) is provided on the outer wall of the luminous chamber body (1) close to the connecting block (3), a filter (5) for sealing the nitrogen luminous chamber (4) is provided on the outer wall of the luminous chamber body (1), a convex lens (6) is provided inside the connecting block (3), and the photomultiplier tube (2), the convex lens (6) and the nitrogen luminous chamber (4) are coaxially arranged; An air outlet (7) and two air inlet holes (8) are provided on the outer wall of the light-emitting chamber body (1); one end of the air outlet (7) and one end of the two air inlet holes (8) are both connected to the nitrogen light-emitting chamber (4); and the other end of the air outlet (7) is connected to a vacuum pump (9).

2. The trace chemiluminescent nitrogen detector according to claim 1, characterized in that A first sealing block is provided in one of the air inlet holes (8), and a nitric oxide air inlet pipe (10) is sleeved in the first sealing block. One end of the nitric oxide air inlet pipe (10) passes through the air inlet hole (8) and extends to the interior of the nitrogen light-emitting chamber (4), and the other end of the nitric oxide air inlet pipe (10) extends to the outside of the light-emitting chamber body (1).

3. The trace chemiluminescent nitrogen detector according to claim 2, characterized in that A second sealing block is provided in the other air inlet hole (8), and an ozone air inlet pipe (11) is sleeved in the second sealing block. One end of the ozone air inlet pipe (11) passes through the air inlet hole (8) and extends to the interior of the nitrogen luminescence chamber (4), and the other end of the ozone air inlet pipe (11) extends to the outside of the luminescence chamber body (1).

4. The trace chemiluminescent nitrogen detector according to claim 3, characterized in that The nitric oxide inlet pipe (10) and the ozone inlet pipe (11) are both capillaries.

5. The trace chemiluminescent nitrogen detector according to claim 1, characterized in that A third sealing block is provided in the air outlet (7), and a connecting pipe (12) is sleeved in the third sealing block. One end of the connecting pipe (12) extends to the outside of the light-emitting chamber body (1) and is connected to the vacuum pump (9).

6. The trace chemiluminescent nitrogen detector according to claim 1, characterized in that The convex lens (6) is a compound lens.

7. The trace chemiluminescent nitrogen detector according to claim 1, characterized in that The connecting block (3) is detachably connected to the photomultiplier tube (2) via bolts (13).

8. The trace chemiluminescent nitrogen detector according to claim 1, characterized in that A first support block (14) is provided at one end of the photomultiplier tube (2) away from the light-emitting chamber body (1), a second support block (15) is provided on the outer wall of the light-emitting chamber body (1), and the outer walls of the first support block (14) and the second support block (15) are covered with a same light-proof sealing cover (16), and the light-proof sealing cover (16) is located outside the photomultiplier tube (2).

Images