Peroxyacetyl nitrate gas synthesis device

Abstract

The utility model provides a peroxyacetyl nitrate gas synthesis device, which belongs to the technical field of gas synthesis, the peroxyacetyl nitrate gas synthesis device comprises a feeding assembly, a premixer, a synthesis pool and an ultraviolet light source, the feeding assembly comprises an acetone outlet, a nitric oxide outlet and a synthesis air outlet; the premixer comprises an outer cylinder and an inner cylinder arranged on the inner ring of the outer cylinder at intervals, a temperature adjusting cavity is formed in the space between the inner cylinder and the outer cylinder, a temperature adjusting assembly is arranged in the temperature adjusting cavity, and three air inlets distributed at intervals up and down are formed in one end of the inner cylinder. The three air inlets are respectively communicated with the acetone outlet, the nitric oxide outlet and the synthetic air outlet; the synthesis tank is provided with a spiral reaction cavity, openings are formed in the two ends of the reaction cavity, and one opening is communicated with the mixed gas outlet and the synthesis air outlet; and the ultraviolet light source is positioned at the axis of the reaction cavity.

Description

Technical Field

[0001] The utility model belongs to the technical field of gas synthesis, and in particular relates to a peroxyacetyl nitrate gas synthesis device. Background Art

[0002] Peroxyacetyl nitrate (PAN) is an important secondary organic pollutant in the atmospheric environment, with the chemical formula CH 3 COO 2 NO 2 PAN in the atmosphere has significant negative impacts on human health and plant growth. It has a strong irritating effect on the human body, and can even cause breathing difficulties and abnormal lung function. PAN's strong oxidizing property causes serious corrosion to plants and buildings. The current detection method for PAN is mainly gas chromatography (GC) combined with electron capture detector (ECD). The above detection method has high selectivity and sensitivity for electronegative compounds and is the most widely used in field observations of atmospheric PAN. Instruments based on this method need to be calibrated regularly using standard concentrations of PAN gas.

[0003] The technical route generally adopted by the existing PAN standard gas generator is: acetone standard solution and NO are decomposed under ultraviolet light, and peroxyacetyl free radicals are generated when in contact with oxygen, and NO is converted into NO under the action of oxygen. 2 , and then combined with peroxyacetyl radicals to generate PAN. The acetone standard solution in the PAN standard gas generator needs to be converted into a high-concentration standard gas by bubbling, which has poor control accuracy and large standard gas concentration error; when irradiating with ultraviolet light, the ultraviolet light irradiation is uneven, the PAN synthesis efficiency is not high, resulting in a certain degree of waste, and some uncontrollable by-products will be synthesized and mixed into the standard gas as impurities. Utility Model Content

[0004] The embodiment of the utility model provides a peroxyacetyl nitrate gas synthesis device, which aims to solve the technical problems of poor acetone control accuracy, large concentration error, uneven ultraviolet lamp irradiation, uncontrollable intensity, low PAN synthesis efficiency, and easy mixing of impurities in the existing PAN standard gas generation device.

[0005] To achieve the above object, the technical solution adopted by the utility model is: to provide a peroxyacetyl nitrate gas synthesis device, comprising:

[0006] a feed assembly including an acetone outlet, a nitric oxide outlet, and a synthetic air outlet;

[0007] A premixer, comprising an outer cylinder, and an inner cylinder arranged at intervals on the inner circle of the outer cylinder, wherein the space between the inner cylinder and the outer cylinder forms a temperature adjustment chamber, wherein a temperature adjustment component is arranged in the temperature adjustment chamber, wherein one end of the inner cylinder is provided with three air inlets spaced apart from each other, wherein the three air inlets are respectively connected to the acetone outlet, the nitric oxide outlet and the synthetic air outlet, and the other end of the inner cylinder is provided with a mixed gas outlet;

[0008] A synthesis tank, having a spiral reaction chamber, both ends of the reaction chamber are provided with openings, one of the openings is connected to the mixed gas outlet and the synthetic air outlet respectively, and the other opening is used to discharge the standard gas;

[0009] The ultraviolet light source is located at the axis of the reaction chamber, and lamp beads are evenly distributed on the periphery of the ultraviolet light source.

[0010] In a possible implementation, the synthesis pool is a spiral tube, and the inner cavity of the spiral tube forms the reaction chamber;

[0011] Alternatively, the synthesis tank is a cylindrical tube structure, and the reaction chamber is arranged on the side wall of the synthesis tank and is located between the inner surface and the outer surface of the synthesis tank.

[0012] In a possible implementation, the peroxyacetyl nitrate gas synthesis device further includes a first bracket and a second bracket, the first bracket includes a clamp, the clamp is fixed to the outer periphery of the synthesis tank, and the second bracket is fixed to both ends of the ultraviolet light source.

[0013] In a possible implementation, the first bracket also includes a support leg and a threaded connector, the clamp includes two semicircular fixing plates, both ends of the fixing plates are provided with connecting parts, the connecting parts are provided with a first through hole, the top of the leg is provided with a second through hole corresponding to the first through hole, and the threaded connector is connected to the first through hole and the second through hole.

[0014] In a possible implementation, the second brackets are respectively disposed at two ends of the synthesis pool, and the ultraviolet light source extends from the two ends of the synthesis pool to be connected to the second brackets.

[0015] In a possible implementation, the second bracket includes a support column and an insertion rod fixedly connected to the top of the support column, and an end of the ultraviolet light source is provided with a socket that cooperates with the insertion rod.

[0016] In a possible implementation, the peroxyacetyl nitrate gas synthesis device further includes a synthesis platform, and the feed assembly, the premixer, the first bracket and the second bracket are all installed on the synthesis platform.

[0017] In a possible implementation, the ultraviolet light source is a columnar structure with a circular or rectangular cross-section, and a plurality of lamp beads are evenly distributed along the axial direction of the ultraviolet light source. The lamp beads in the same row are preset as a light source group, and a plurality of light source groups are evenly distributed around the axial direction of the ultraviolet light source.

[0018] In a possible implementation, the temperature adjustment component includes:

[0019] A heating wire is wound around the outer circumference of the inner cylinder;

[0020] The semiconductor refrigeration sheet is placed in the temperature adjustment chamber.

[0021] In a possible implementation, the peroxyacetyl nitrate gas synthesis device further includes a controller connected to the ultraviolet light source, and a control button disposed between the controller and the ultraviolet light source.

[0022] In the embodiment of the present application, compared with the prior art, when acetone, nitric oxide, and synthetic air enter the premixer, acetone is connected to the top air inlet, nitric oxide is connected to the middle air inlet, and synthetic air is connected to the bottom air inlet. After being evenly mixed, the mixed gas enters the reaction chamber, and synthetic air is introduced into the reaction chamber at the same time. Under the irradiation of the ultraviolet light source, the mixed gas reacts in the reaction chamber to generate PAN standard gas. The upper and lower distribution forms of the air inlet of the premixer in the utility model can ensure that the mixed gas is in a laminar state in the premixer and is evenly mixed; the temperature regulating component in the premixer can adjust the temperature in the premixer to ensure that acetone, nitric oxide, and synthetic air are fully mixed inside without chemical reaction in advance, and ensure that only PAN standard gas is generated in the reaction chamber; the reaction chamber is spiral, which increases the gas travel path, prolongs the residence time of the mixed gas, improves the synthesis efficiency, and inhibits the generation of by-products (i.e., avoids the mixing of impurities in PAN); the ultraviolet light source is at the axial position of the spiral, and the illumination of the synthesis pool is uniform, which improves the synthesis efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the working process of a peroxyacetyl nitrate gas synthesis device provided in an embodiment of the utility model;

[0024] Figure 2 A schematic diagram of the top view of the peroxyacetyl nitrate gas synthesis device provided in an embodiment of the utility model;

[0025] Figure 3 A schematic diagram of the three-dimensional structure of a peroxyacetyl nitrate gas synthesis device provided by an embodiment of the utility model;

[0026] Figure 4 This is a schematic diagram of the cross-sectional structure of the premixer used in the embodiment of the utility model.

[0027] Description of reference numerals:

[0028] 10-feeding assembly;

[0029] 20-premixer; 21-outer cylinder; 22-inner cylinder; 23-temperature adjustment component; 231-heating wire; 232-semiconductor cooling sheet; 24-air inlet;

[0030] 30-synthetic pool;

[0031] 40-ultraviolet light source; 41-lamp beads; 42-mounting plate;

[0032] 50-first bracket; 51-leg; 52-clamp; 53-connecting part;

[0033] 60-second bracket; 61-support column; 62-insertion rod;

[0034] 70-Synthesis platform;

[0035] 80-Controller. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] Please also read Figures 1 to 4 , the peroxyacetyl nitrate gas synthesis device provided by the utility model is now described. The peroxyacetyl nitrate gas synthesis device comprises a feed assembly 10, a premixer 20, a synthesis tank 30 and an ultraviolet light source 40, wherein the feed assembly 10 comprises an acetone outlet, a nitric oxide outlet and a synthetic air outlet; the premixer 20 comprises an outer cylinder 21, and an inner cylinder 22 arranged at intervals in the inner circle of the outer cylinder 21, the space between the inner cylinder 22 and the outer cylinder 21 forms a temperature adjustment chamber, a temperature adjustment assembly 23 is arranged in the temperature adjustment chamber, one end of the inner cylinder 22 is provided with three air inlets 24 spaced apart from each other, the three air inlets 24 are respectively connected to the acetone outlet, the nitric oxide outlet and the synthetic air outlet, and the other end of the inner cylinder 22 is provided with a mixed gas outlet; the synthesis tank 30 has a spiral reaction chamber, both ends of the reaction chamber are provided with openings, one of which is respectively connected to the mixed gas outlet and the synthetic air outlet, and the other opening is used to discharge the standard gas; the ultraviolet light source 40 is located at the axis of the reaction chamber, and lamp beads 41 are evenly distributed on the periphery of the ultraviolet light source 40.

[0038] For ease of understanding, the acetone outlet is connected to the uppermost air inlet 24 , the synthetic air is connected to the lowermost air inlet 24 , and the nitric oxide outlet is connected to the middle air inlet 24 .

[0039] It should be noted that the outer cylinder 21 in the premixer 20 is opaque (isolates ultraviolet rays). Synthetic air is zero-grade air, or cold air, which is a gas that has been freed of water vapor, carbon dioxide and other impurities. It is made of high-purity nitrogen and high-purity oxygen in the proportion of air. Synthetic air is a prior art and will not be described in detail here.

[0040] Specifically, the feed assembly 10 includes three feed pipes, each of which is equipped with a mass flow controller 80, and the outlets of the three feed pipes correspond to an acetone outlet, a nitric oxide outlet, and a synthetic air outlet, respectively.

[0041] Compared with the prior art, the peroxyacetyl nitrate gas synthesis device provided in this embodiment is different from the prior art in that when acetone, nitric oxide, and synthetic air enter the premixer 20, acetone is connected to the uppermost air inlet 24, nitric oxide is connected to the middle air inlet 24, and synthetic air is connected to the lowermost air inlet 24. After being evenly mixed, the mixed gas enters the reaction chamber, and synthetic air is simultaneously introduced into the reaction chamber. Under the irradiation of the ultraviolet light source 40, the mixed gas reacts in the reaction chamber to generate PAN standard gas. The upper and lower distribution form of the air inlet 24 of the premixer 20 in the utility model can ensure that the mixed gas is in a laminar state in the premixer 20 and is mixed evenly; the temperature regulating component 23 in the premixer 20 can adjust the temperature in the premixer 20 to ensure that acetone, nitric oxide, and synthetic air are fully mixed inside without premature chemical reaction, and only PAN standard gas is generated in the reaction chamber; the reaction chamber is spiral, which increases the gas travel path, prolongs the residence time of the mixed gas, improves the synthesis efficiency, and inhibits the generation of by-products (i.e., avoids impurities from mixing into PAN); the ultraviolet light source 40 is at the axial center position of the spiral, and the illumination of the synthesis pool 30 is uniform, thereby improving the synthesis efficiency.

[0042] In some embodiments, a specific embodiment of the synthesis tank 30 can be as follows: Figures 1 to 3 See the structure shown. Figures 1 to 3 , the synthesis pool 30 is a spiral tube, and the inner cavity of the spiral tube forms a reaction chamber; or, the synthesis pool 30 is a cylindrical tube structure (not shown in the figure), and the reaction chamber is arranged on the side wall of the synthesis pool 30 and is located between the inner surface and the outer surface of the synthesis pool 30. When the synthesis pool 30 is a spiral tube, the straight tube can be conveniently bent into a spiral shape, which is convenient for processing, but rebound may occur during use, resulting in an increase in the interval between adjacent circles, and the axial length of the overall spiral tube becomes longer, which may easily cause the ultraviolet light source 40 to be unable to cover; the cylindrical tube structure has a fixed axial length, which can ensure the contact area with the ultraviolet light source 40, but the spiral cavity inside it is not easy to process, and the synthesis pool 30 can be divided into two cylinders. After the spiral groove is processed on the outer circumference of the inner cylinder, the outer cylinder 21 is clamped on the outer circumference of the inner cylinder 22, and the inner circumference of the outer cylinder 21 is abutted against the outer circumference of the inner cylinder 22 to enclose and form a spiral reaction chamber.

[0043] In some embodiments, an improved embodiment of the above-mentioned peroxyacetyl nitrate gas synthesis device can be adopted as follows Figures 2 to 3 See the structure shown. Figures 2 to 3 The peroxyacetyl nitrate gas synthesis device further includes a first bracket 50 and a second bracket 60. The first bracket 50 includes a clamp 52, which is fixed to the outer periphery of the synthesis pool 30, and the second bracket 60 is fixed to both ends of the ultraviolet light source 40. The synthesis pool 30 is fixed by the first bracket 50, and the ultraviolet light source 40 is fixed by the second bracket 60, so that the positional relationship between the first bracket 50 and the ultraviolet light source 40 can be adjusted conveniently.

[0044] Specifically, the first bracket 50 and the second bracket 60 can both be configured as components that can be extended and retracted up and down, so as to facilitate adjustment of the positional relationship between the ultraviolet light source 40 and the synthesis pool 30 .

[0045] In some embodiments, a specific implementation of the first bracket 50 can be as follows: Figures 2 to 3 See the structure shown. Figures 2 to 3 The first bracket 50 also includes a leg 51 and a threaded connector. The clamp 52 includes two semicircular fixing plates. Both ends of the fixing plates are provided with a connecting portion 53. The connecting portion 53 is provided with a first through hole. The top of the leg 51 is provided with a second through hole corresponding to the first through hole. The threaded connector is connected to the first through hole and the second through hole. After the two semicircular fixing plates are sleeved on the outer periphery of the synthesis pool 30, the first through hole on the fixing plate is matched with the second through hole on the leg 51, and then tightened to complete the connection between the synthesis pool 30 and the first bracket 50, which is convenient for loading and unloading the synthesis pool 30.

[0046] In some embodiments, an improved implementation of the above-mentioned ultraviolet light source 40 can be adopted as follows Figures 2 to 3 See the structure shown. Figures 2 to 3 , the second bracket 60 is respectively arranged at both ends of the synthesis pool 30, and the ultraviolet light source 40 extends from both ends of the synthesis pool 30 to be connected with the second bracket 60. The ultraviolet light source 40 extends from both ends of the synthesis pool 30, that is, the central area of ​​the synthesis pool 30 is a through cavity. If the ultraviolet light source 40 is completely in the internal space of the synthesis pool 30, the second bracket 60 also needs to pass through the synthesis pool 30. The ultraviolet light source 40 extends to be conveniently fixed to the second bracket 60, which is not only convenient for operation, but also does not reduce the volume of the reaction chamber due to the second bracket 60 occupying the space of the synthesis pool 30; at the same time, since the two ends of the ultraviolet light source 40 extend, good heat dissipation can be achieved, and the service life of the ultraviolet light source 40 is extended.

[0047] In some embodiments, a specific implementation of the second bracket 60 can be as follows: Figures 2 to 3 See the structure shown. Figures 2 to 3The second bracket 60 includes a support column 61 and an insertion rod 62 fixed to the top of the support column 61. The end of the ultraviolet light source 40 is provided with a socket that matches the insertion rod 62. When the insertion rod 62 and the support column 61 are both cylindrical, the diameter of the insertion rod 62 is smaller than the diameter of the support column 61, and the two are coaxial; when the insertion rod 62 and the support column 61 are both rectangular columns, the width of the insertion rod 62 is smaller than the width of the support column 61. The above two methods can form a lap step between the insertion rod 62 and the support column 61.

[0048] A corresponding mounting plate 42 can be provided at the end of the ultraviolet light source 40, and a socket is provided on the mounting plate 42. After the ultraviolet light source 40 passes through the space in the middle of the synthesis pool 30, the insertion rod 62 passes through the socket. The mounting plate 42 is placed on the overlapping step to complete the fixation of the ultraviolet light source 40, which is convenient for loading and unloading of the ultraviolet light source 40.

[0049] In some embodiments, an improved embodiment of the above-mentioned peroxyacetyl nitrate gas synthesis device can be adopted as follows Figures 2 to 3 See the structure shown. Figures 2 to 3 The peroxyacetyl nitrate gas synthesis device further includes a synthesis platform 70, and the feed assembly 10, the premixer 20, the first bracket 50 and the second bracket 60 are all installed on the synthesis platform 70. The synthesis platform 70 forms the present embodiment as a whole, and the synthesis platform 70 can be directly taken and placed during transportation, which is convenient for use.

[0050] For easy operation, structures such as handles and rollers may also be provided on the synthesis platform 70. It should be noted that the premixer 20 may be installed on the synthesis platform 70 using the same structure as the first bracket 50.

[0051] In some embodiments, a specific distribution method of the lamp beads 41 can be as follows: Figures 2 to 3 See the structure shown. Figures 2 to 3 The ultraviolet light source 40 is a columnar structure with a circular or rectangular cross section, and a plurality of lamp beads 41 are evenly distributed along the axial direction of the ultraviolet light source 40. The lamp beads 41 in the same row are preset as a light source group, and the light source groups are evenly distributed around the axial direction of the ultraviolet light source 40. The lamp beads 41 are evenly distributed along the axial direction, and the light source groups are evenly distributed around the axial direction, so that the ultraviolet light can be irradiated 360 degrees, which increases the illumination area of ​​the gas synthesis reaction, improves the synthesis efficiency, and inhibits the generation of by-products.

[0052] In some embodiments, a specific implementation of the temperature adjustment component 23 can be as follows: Figure 4 See the structure shown. Figure 4The temperature adjustment component 23 includes a heating wire 231 and a semiconductor cooling sheet 232. The heating wire 231 is wound around the outer periphery of the inner tube 22; the semiconductor cooling sheet 232 is placed in the temperature adjustment cavity. The heating wire 231 is used for temperature increase adjustment, and the semiconductor cooling sheet 232 is used for temperature decrease adjustment. It can be flexibly controlled according to actual use conditions, and the adjustment range is relatively wide.

[0053] In some embodiments, the improved implementation of the above-mentioned peroxyacetyl nitrate gas synthesis device can be adopted as follows Figures 2 to 3 See the structure shown. Figures 2 to 3 The peroxyacetyl nitrate gas synthesis device further includes a controller 80 connected to the ultraviolet light source 40, and a control button disposed between the controller 80 and the ultraviolet light source 40. The controller 80 can control the light intensity of the ultraviolet light source 40, and the control button can control the opening and closing of the ultraviolet light source 40. The intensity of the ultraviolet light source 40 is controllable, which is convenient for real-time adjustment.

[0054] Specifically, the controller 80 can also control the temperature adjustment component 23. By allowing the controller 80 to participate in temperature control, the adjustment accuracy is higher.

[0055] In order to protect the ultraviolet light source 40, a fan may be provided. When the ultraviolet light source 40 works for a long time, the fan may be turned on to cool down the ultraviolet light source 40 to avoid overheating and damage.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A peroxyacetyl nitrate gas synthesis device, characterized in that: include: a feed assembly including an acetone outlet, a nitric oxide outlet, and a synthetic air outlet; A premixer, comprising an outer cylinder, and an inner cylinder arranged at intervals on the inner circle of the outer cylinder, wherein the space between the inner cylinder and the outer cylinder forms a temperature adjustment chamber, wherein a temperature adjustment component is arranged in the temperature adjustment chamber, wherein one end of the inner cylinder is provided with three air inlets spaced apart from each other, wherein the three air inlets are respectively connected to the acetone outlet, the nitric oxide outlet and the synthetic air outlet, and the other end of the inner cylinder is provided with a mixed gas outlet; A synthesis tank, having a spiral reaction chamber, both ends of the reaction chamber are provided with openings, one of the openings is connected to the mixed gas outlet and the synthetic air outlet respectively, and the other opening is used to discharge the standard gas; The ultraviolet light source is located at the axis of the reaction chamber, and lamp beads are evenly distributed on the periphery of the ultraviolet light source.

2. The peroxyacetyl nitrate gas synthesis device according to claim 1, characterized in that: The synthesis pool is a spiral tube, and the inner cavity of the spiral tube forms the reaction chamber; Alternatively, the synthesis tank is a cylindrical tube structure, and the reaction chamber is arranged on the side wall of the synthesis tank and is located between the inner surface and the outer surface of the synthesis tank.

3. The peroxyacetyl nitrate gas synthesis device according to claim 1, characterized in that: The peroxyacetyl nitrate gas synthesis device further comprises a first bracket and a second bracket, wherein the first bracket comprises a clamp fixed to the outer periphery of the synthesis tank, and the second bracket is fixed to both ends of the ultraviolet light source.

4. The peroxyacetyl nitrate gas synthesis device according to claim 3, characterized in that: The first bracket also includes a support leg and a threaded connector, the clamp includes two semicircular fixing plates, both ends of the fixing plates are provided with connecting parts, the connecting parts are provided with a first through hole, the top of the support leg is provided with a second through hole corresponding to the first through hole, and the threaded connector is connected to the first through hole and the second through hole.

5. The peroxyacetyl nitrate gas synthesis device according to claim 3, characterized in that: The second brackets are respectively arranged at two ends of the synthesis pool, and the ultraviolet light sources extend from the two ends of the synthesis pool to be connected with the second brackets.

6. The peroxyacetyl nitrate gas synthesis device according to claim 5, characterized in that: The second bracket includes a support column and an insertion rod fixedly connected to the top of the support column, and the end of the ultraviolet light source is provided with a socket matched with the insertion rod.

7. The peroxyacetyl nitrate gas synthesis device according to claim 3, characterized in that: The peroxyacetyl nitrate gas synthesis device further comprises a synthesis platform, and the feed assembly, the premixer, the first bracket and the second bracket are all installed on the synthesis platform.

8. The peroxyacetyl nitrate gas synthesis device according to claim 1, characterized in that: The ultraviolet light source is a columnar structure with a circular or rectangular cross-section. A plurality of lamp beads are evenly distributed along the axial direction of the ultraviolet light source. The lamp beads in the same row are preset as a light source group. There are multiple light source groups evenly distributed around the axial direction of the ultraviolet light source.

9. The peroxyacetyl nitrate gas synthesis device according to claim 1, characterized in that: The temperature adjustment component comprises: A heating wire is wound around the outer circumference of the inner cylinder; The semiconductor refrigeration sheet is placed in the temperature adjustment chamber.

10. The peroxyacetyl nitrate gas synthesis device according to claim 1, characterized in that: The peroxyacetyl nitrate gas synthesis device also includes a controller connected to the ultraviolet light source, and a control button arranged between the controller and the ultraviolet light source.

Images