Generating device for formaldehyde bottled gas standard substance

Abstract

The utility model discloses a generation device of a formaldehyde bottled gas standard substance. The generation device comprises a sublimation device, a catalytic cracking device, a gas storage bottle and a gas carrying system, according to the utility model, the formaldehyde bottled gas standard substance is prepared by a static cracking method, solid powdery trioxymethylene is adopted as a raw material, and a new way of preparing the gas standard substance from solid to gas is realized by regulating parameters such as cracking temperature, reaction time and the like. The device is simple in overall structure composition, small in size, convenient to disassemble and assemble and flexible to use, and the prepared formaldehyde gas standard substance is stored by adopting a gas cylinder, is convenient to carry and transport and can be flexibly applied to field measurement outside a specific laboratory. In addition, passivation coatings are arranged in the formaldehyde gas storage bottle and the formaldehyde conveying pipeline, so that the formaldehyde gas is prevented from being easily adsorbed, reacted and the like in the pipeline in the preparation process and the storage process in the gas bottle, the stable storage of the gas standard substance in the formaldehyde bottle is realized, and the accurate quantity value of the gas standard substance is ensured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of measurement technology relates to formaldehyde gas standard substance preparation device, especially, relate to a kind of generation device of formaldehyde bottled gas standard substance. BACKGROUND

[0002] When detecting formaldehyde concentration in air, formaldehyde gas standard substance with accurate and stable value is needed to calibrate formaldehyde concentration detector to ensure accurate and reliable measurement results. Formaldehyde gas standard substance is often prepared by dynamic generation method, which principle is to crack trioxymethylene in constant temperature diffusion pipe and diffuse formaldehyde gas, and obtain formaldehyde standard gas by dilution with flow carrier gas.

[0003] But dynamic generation device is complex in structure and large in size, only suitable for operation in specific laboratory, difficult to apply to field, which limits the application scene of formaldehyde gas standard substance. To solve this problem, the utility model provides a kind of generation device of formaldehyde bottled gas standard substance. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a kind of generation device of formaldehyde bottled gas standard substance, which prepares formaldehyde bottled gas standard substance by static cracking method, formaldehyde gas standard substance is stored in gas cylinder, convenient to carry and transport, can be flexibly applied to field measurement and calibration outside specific laboratory, to solve the problems existing in the prior art.

[0005] To achieve the above object, the utility model provides the following scheme:

[0006] The utility model provides a kind of generation device of formaldehyde bottled gas standard substance, comprising:

[0007] Sublimation device, at least used for containing solid trioxymethylene in it, to make the solid trioxymethylene sublimate to generate trioxymethylene vapor;

[0008] Catalytic cracking device, at least used for containing cracking catalyst in the catalytic cracking device, the catalytic cracking device is used to catalytically crack the trioxymethylene vapor generated by the sublimation device to generate formaldehyde gas;

[0009] Gas storage bottle, connected with the catalytic cracking device, can collect the formaldehyde gas;

[0010] Carrier gas system, connected with the gas storage bottle, is used to dilute the formaldehyde gas in the gas storage bottle, to prepare formaldehyde bottled gas standard substance in the gas storage bottle.

[0011] Some embodiments, the sublimation device comprises:

[0012] a reaction tube one, in which the solid trioxane is contained, and a drying agent for drying the solid trioxane.

[0013] a multi-way valve, which comprises at least a first valve port, a second valve port and a third valve port, the first valve port is connected with the gas outlet of the reaction tube one, the second valve port and the third valve port are connected with the carrier gas system and the catalytic cracking device respectively, and the multi-way valve can control the third valve port to communicate with the first valve port or the second valve port.

[0014] In some embodiments, the sublimation device further comprises a passivated quartz wool, which is detachably arranged at the gas outlet end of the reaction tube one.

[0015] In some embodiments, the sublimation device further comprises a heating device one, which comprises at least one of an electric heating wire and an electric heating tape, and at least one of the electric heating wire and the electric heating tape is wound outside the reaction tube one.

[0016] In some embodiments, the catalytic cracking device comprises a reaction tube two, in which at least the cracking catalyst is contained, and a heating device two, which comprises at least one of an electric heating wire and an electric heating tape, and at least one of the electric heating wire and the electric heating tape is wound outside the reaction tube two.

[0017] In some embodiments, the heating device two further comprises a thermal insulation layer wrapped outside the electric heating wire and / or the electric heating tape.

[0018] In some embodiments, the catalytic cracking device comprises a plurality of reaction tube twos connected in series through a formaldehyde delivery pipeline, wherein the first end of the reaction tube two is connected with the third valve port through the formaldehyde delivery pipeline, and the last end of the reaction tube two is connected with the gas cylinder through the formaldehyde delivery pipeline.

[0019] In some embodiments, the inner wall of the gas cylinder and / or the inner wall of the formaldehyde delivery pipeline is provided with a passivation coating.

[0020] In some embodiments, the inner diameter of the first formaldehyde delivery pipeline is not less than the inner diameter of the second formaldehyde delivery pipeline, and the inner diameter of the second formaldehyde delivery pipeline is greater than the inner diameter of the third formaldehyde delivery pipeline, wherein the first formaldehyde delivery pipeline is the formaldehyde delivery pipeline between the first end of the reaction tube two and the third valve port, the second formaldehyde delivery pipeline is the formaldehyde delivery pipeline between two reaction tube twos, and the third formaldehyde delivery pipeline is the formaldehyde delivery pipeline between the last end of the reaction tube two and the gas cylinder.

[0021] In some embodiments, the multi-way valve is a three-way ball valve.

[0022] In some embodiments, the carrier gas system includes a carrier gas cylinder and a carrier gas delivery line, the carrier gas cylinder being connected to the second valve port via the carrier gas delivery line.

[0023] The present application has the following technical effects compared with the prior art:

[0024] The device for generating formaldehyde bottled gas standard substance has novel and reasonable structure, and is used for preparing formaldehyde bottled gas standard substance by a static cracking method, adopts solid powder trioxane as raw material, and realizes a new way of preparing gas standard substance from solid to gas by adjusting and controlling parameters such as cracking temperature and reaction time. The device has simple overall structure, small volume, and is convenient to disassemble and assemble, flexible to use, and the prepared formaldehyde gas standard substance is stored in a gas cylinder, convenient to carry and transport, and can be flexibly applied to on-site measurement and calibration outside a specific laboratory, and breaks through the limitation that traditional dynamic formaldehyde standard gas is only suitable for laboratory testing.

[0025] In some technical solutions disclosed by the present application, a passivation coating is arranged in the formaldehyde storage cylinder and the formaldehyde delivery line, so that the formaldehyde gas is prevented from being adsorbed and reacted in the pipeline during preparation and storage in the cylinder, the formaldehyde bottled gas standard substance is stably stored, and the quantity value is ensured to be accurate.

[0026] In some technical solutions disclosed by the present application, a carrier gas is used to purge the reaction tube two for generating formaldehyde gas, so that the formaldehyde gas can be completely transferred out and loss is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0028] Figure 1 A structural schematic view of the device for generating formaldehyde bottled gas standard substance disclosed in the embodiments of the present application is shown in the figure.

[0029] Figure 2 A schematic view of the first valve port and the third valve port being communicated in the multi-way valve disclosed in the embodiments of the present application is shown in the figure.

[0030] Figure 3 A schematic view of the second valve port and the third valve port being communicated in the multi-way valve disclosed in the embodiments of the present application is shown in the figure.

[0031] Figure 4The utility model discloses three valve ports of the multi -way valve of the embodiment of the utility model are not connected to the schematic diagram of each other.

[0032] Figure 5 The utility model discloses the schematic diagram of article placement of reaction tube two.

[0033] In the drawing, the reference signs are:

[0034] 100, formaldehyde bottled gas standard substance's generating device;

[0035] 1, reaction tube one;

[0036] 2, multi -way valve;21, first valve port;22, second valve port;23, third valve port;

[0037] 3, gas cylinder;

[0038] 4, carrier gas system;41, carrier gas cylinder;42, carrier gas delivery pipeline;

[0039] 5, reaction tube two;

[0040] 6, formaldehyde delivery pipeline;

[0041] 7, solid trioxane;

[0042] 8, cracking catalyst;

[0043] 9, passivated quartz wool;

[0044] 10, stainless steel net;

[0045] 11, drying agent. DETAILED DESCRIPTION

[0046] The technical scheme in the embodiments of the utility model will be described clearly and completely below in conjunction with the drawings of the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the utility model.

[0047] The utility model discloses a kind of formaldehyde bottled gas standard substance's generating device, which is prepared by static cracking method formaldehyde bottled gas standard substance, formaldehyde gas standard substance is stored using gas cylinder, it is convenient to carry transport, it can be flexibly applied to specific laboratory outside the field measurement, to solve the problems existing in prior art.

[0048] To make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the utility model will be further described in detail in conjunction with the drawings and specific embodiments.

[0049] Example 1

[0050] like Figure 1 As shown, this embodiment provides a formaldehyde bottled gas standard material generating apparatus 100, including a sublimation device, a catalytic cracking device, a gas storage bottle 3, and a carrier gas system 4. The sublimation device is used to hold at least solid trioxymethylene 7, so that the solid trioxymethylene 7 sublimates to generate trioxymethylene vapor; the catalytic cracking device is used to hold at least a cracking catalyst 8, which is used to catalytically crack the trioxymethylene vapor generated by the sublimation device to generate formaldehyde gas; the gas storage bottle 3 is connected to the catalytic cracking device and can collect formaldehyde gas; the carrier gas system 4, connected to the gas storage bottle 3, is used to introduce a carrier gas such as nitrogen into the gas storage bottle 3 to dilute the formaldehyde gas in the gas storage bottle 3, thereby obtaining the formaldehyde bottled gas standard material in the gas storage bottle 3. The above-mentioned formaldehyde bottled gas standard material generating apparatus 100 is based on the static cracking method to prepare formaldehyde bottled gas standard material, using solid powdered trioxymethylene as raw material, and by controlling parameters such as cracking temperature and reaction time, a new approach to preparing gas standard material "from solid to gas" is realized. Furthermore, the device has a simple overall structure, small size, is easy to disassemble and assemble, and is flexible in use. The formaldehyde gas standard substance produced is stored in gas cylinders, which is easy to carry and transport, and can be flexibly applied to on-site measurements outside of specific laboratories.

[0051] In some implementations, such as Figure 1 As shown, the aforementioned sublimation device includes a reaction tube 1 and a multi-port valve 2. The reaction tube 1 contains solid paraformaldehyde 7 and a desiccant 11, whose main function is to absorb the water of crystallization in the solid paraformaldehyde. The desiccant 11 is preferably phosphorus pentoxide. To prevent the solid paraformaldehyde 7 and the pyrolysis catalyst 8 from being discharged with the formaldehyde gas, a detachable passivated silica cotton 9 is installed at the outlet of the reaction tube 1. The passivated silica cotton 9 mainly serves to intercept solid powder or particles. The multi-port valve 2 includes at least a first valve port 21, a second valve port 22, and a third valve port 23. The first valve port 21 is connected to the outlet of the reaction tube 1, and the second valve port 22 and the third valve port 23 are respectively connected to the carrier gas system 4 and the catalytic pyrolysis device. The multi-port valve 2 can control the connection between the third valve port 23 and either the first valve port 21 or the second valve port 22. The multi-port valve 2 integrates the reaction tube 1, carrier gas system 4, and catalytic cracking unit, which not only simplifies the structure and reduces the number of internal components, but also allows for sensitive switching between different valve ports and good shut-off effect, thus improving the reliability of the system. Passivated silica cotton 9 is generally made of silane-based silica cotton.

[0052] In some implementations, such as Figure 1As shown, in order to improve the sublimation efficiency of solid trioxane 7, the sublimation device preferably further comprises a first heating device, which comprises at least one of an electric heating wire and an electric heating belt, and at least one of the electric heating wire and the electric heating belt is wound outside the first reaction tube 1 to heat the first reaction tube 1. In order to facilitate temperature control, the electric heating wire and the electric heating belt are generally used in combination with a thermocouple and a temperature controller to facilitate real-time monitoring of the heating temperature of the electric heating wire and the electric heating belt, and the heating temperature of the electric heating wire and the electric heating belt is flexibly adjusted by using the temperature controller, which is beneficial to the efficient and stable operation of the formaldehyde gas preparation process. In order to further improve the sublimation efficiency of trioxane and improve the preparation rate of formaldehyde, the above-mentioned first heating device can further be provided with a heat preservation layer wrapped outside the electric heating wire and / or the electric heating belt. The heat preservation layer can be made of heat preservation cotton or aluminum foil.

[0053] In some embodiments, as shown in Figure 1 As shown, the above-mentioned catalytic cracking device comprises a second reaction tube 5 and a second heating device, the second reaction tube 5 is at least used for containing a cracking catalyst 8, and the second heating device comprises at least one of an electric heating wire and an electric heating belt, and at least one of the electric heating wire and the electric heating belt is wound outside the second reaction tube 5 to heat the second reaction tube 5. In order to facilitate temperature control, the electric heating wire and the electric heating belt of the second heating device are generally used in combination with a thermocouple and a temperature controller to facilitate real-time monitoring of the heating temperature of the electric heating wire and the electric heating belt, and the heating temperature of the electric heating wire and the electric heating belt is flexibly adjusted by using the temperature controller, which is beneficial to the efficient and stable operation of the formaldehyde gas preparation process. In order to further improve the formaldehyde conversion efficiency and improve the preparation rate of formaldehyde, the above-mentioned second heating device can further be provided with a heat preservation layer wrapped outside the electric heating wire and / or the electric heating belt. The heat preservation layer can be made of heat preservation cotton or aluminum foil. The above-mentioned second heating device generally uses high-temperature heating of 150°C to 400°C to ensure the smooth progress of the cracking catalytic reaction.

[0054] In some embodiments, the above-mentioned catalytic cracking device can simultaneously comprise a plurality of second reaction tubes 5 connected in series through the formaldehyde delivery pipeline 6, wherein the first end of the second reaction tube 5 is connected with the third valve port 23 through the formaldehyde delivery pipeline 6, and the last end of the second reaction tube 5 is connected with the gas storage bottle 3 through the formaldehyde delivery pipeline 6.

[0055] In some embodiments, the inner wall of the gas storage bottle 3 and / or the inner wall of the formaldehyde delivery pipeline 6 is provided with a passivation coating. In order to improve the passivation effect, the inner wall of the gas storage bottle 3 and the inner wall of each formaldehyde delivery pipeline 6 are generally provided with a passivation coating.

[0056] In some embodiments, as shown in Figure 1As shown, two reaction tubes two 5 are preferably arranged in series in the catalytic cracking device, and each reaction tube two 5 is externally provided with the heating device two. In order to distinguish, the formaldehyde delivery pipeline one is defined as the formaldehyde delivery pipeline between the first reaction tube two 5 and the third valve port 23, the formaldehyde delivery pipeline two is defined as the formaldehyde delivery pipeline between the two reaction tubes two 5, and the formaldehyde delivery pipeline three is defined as the formaldehyde delivery pipeline between the tail reaction tube two 5 and the gas cylinder 3. The inner diameter of the formaldehyde delivery pipeline one is not less than that of the formaldehyde delivery pipeline two, and the inner diameter of the formaldehyde delivery pipeline two is greater than that of the formaldehyde delivery pipeline three. Based on this, the pipeline diameter reduction design is formed in the catalytic cracking device along the gas flow direction, which can prolong the flow time of the formaldehyde gas in the pipeline, and further improve the generation purity and conversion rate of the formaldehyde gas.

[0057] In some embodiments, as shown in Figure 5 As shown, the reaction tube two 5 is further provided with a stainless steel mesh 10 and a passivated quartz wool 9 on both sides of the cracking catalyst 8. The stainless steel mesh 10 and the passivated quartz wool 9 in the reaction tube two 5 play a role in intercepting solid particles and fixing the catalyst, so as to avoid the catalyst particles from being transferred with the gas flow and blocking the gas cylinder port.

[0058] In some embodiments, the cracking catalyst 8 can be selected from phosphorus pentoxide.

[0059] In some embodiments, the electric heating wire and / or the electric heating tape are preferably wound on at least one of the formaldehyde delivery pipelines 6, and a heat preservation layer is arranged outside the electric heating wire and / or the electric heating tape. The heat preservation layer can be made of heat preservation cotton or aluminum foil

[0060] In some embodiments, as shown in Figure 1 As shown, the carrier gas system 4 includes a carrier gas cylinder 41 and a carrier gas delivery pipeline 42, and the carrier gas cylinder 41 is connected with the second valve port 22 through the carrier gas delivery pipeline 42. The carrier gas in the carrier gas cylinder 41 includes but is not limited to nitrogen. After the reaction tube two 5 generates the formaldehyde gas, due to the pressure difference between the negative pressure in the gas cylinder 3 and the reaction tube two 5, part of the formaldehyde gas will be transferred to the gas cylinder 3 until the pressure balance between them, and part of the formaldehyde gas will remain in the reaction tube two 5 or the formaldehyde delivery pipeline 6; then the first formaldehyde delivery pipeline 6 of the catalytic cracking device is connected with the carrier gas delivery pipeline 42 through the multi-way valve 2, and nitrogen can be blown into the catalytic cracking device through the carrier gas cylinder 41 to carry all the residual formaldehyde gas into the gas cylinder 3. At the same time, the formaldehyde gas with high purity is easy to polymerize into polyformaldehyde, which is difficult to be stably stored, and therefore it is necessary to dilute it with nitrogen or synthetic air to obtain a gas standard substance with stable value. As can be seen from the above, the carrier gas system 4 is mainly used to assist the cracking generated formaldehyde gas to be completely transferred to the gas cylinder 3, and to dilute the formaldehyde concentration to the target value.

[0061] In some embodiments, the multi-way valve 2 is preferably a three-way ball valve.

[0062] In some embodiments, the above-mentioned generating device 100 of formaldehyde bottled gas standard substance is generally used in cooperation with a vacuumizing device. The vacuumizing device is generally connected with the second valve port 22 or the third valve port 23. The vacuumizing device can be independently arranged and connected with the corresponding valve port of the multi-way valve 2 for use when needed. In addition, the vacuumizing device can also be directly arranged on the carrier gas delivery pipeline 42 and the formaldehyde delivery pipeline 6, and only used when needed and closed when not needed, only serving as a gas flow path.

[0063] In some embodiments, the above-mentioned vacuumizing device can be a vacuum molecular pump group (including a mechanical pump and a molecular pump). The following will make a specific description on the process, principle and technical effect of preparing formaldehyde gas by combining the structure design of the above-mentioned generating device 100 of formaldehyde bottled gas standard substance. The operation process is as follows:

[0064] I. Pre-saturation of gas cylinder

[0065] A 10-liter PW gas cylinder is selected, and an appropriate amount of formaldehyde standard gas (i.e. formaldehyde standard gas substance) is pre-saturated. The amount of formaldehyde standard gas and the pre-saturation time can be flexibly adjusted according to needs.

[0066] II. Experimental operation

[0067] 1. A set of generating device 100 of formaldehyde bottled gas standard substance is used as an experimental reactor. About 0.019 grams of solid trioxane 7, about 0.02 grams of phosphorus pentoxide and passivated quartz wool 9 (in actual application, the amount of each substance can be adjusted according to the concentration of the generated formaldehyde standard gas) are sequentially added into the reaction tube one 1, and the reaction tube one 1 is connected to the first valve port 21. The multi-way valve 2 is adjusted to state one (i.e. the first valve port 21 and the third valve port 23 are communicated) as shown in the figure, and the third valve port 23 is connected to a vacuum molecular pump group (including a mechanical pump and a molecular pump). Figure 2 After the mechanical pump is vacuumized, the molecular pump is vacuumized for about 30 seconds (it should be particularly noted that during this process, the solid trioxane 7 is continuously sublimed, and the vacuum degree cannot reach 10 -6 hPa, and long waiting time will cause loss of trioxane). Then, the multi-way valve 2 is adjusted to state two (i.e. the third valve port 23 and the second valve port 22 are communicated) as shown in the figure. Figure 3

[0068] 2. The initial mass m0 of the experimental reactor is weighed and recorded.

[0069] 3. The mass M0 of the gas storage cylinder 3 is weighed, and then two groups of reaction tube two 5 are connected in series between the third valve port 23 and the gas storage cylinder 3 as shown in the figure. Figure 1

[0070] 4. The second valve port 22 is connected to a vacuum molecular pump group (including a mechanical pump and a molecular pump), and the pipeline is vacuumized to 10​​- 6 hPa. Then the multi-way valve 2 is adjusted to Figure 4 the state three as shown in the figure, that is, the multi-way valve 2 is closed, and each valve port is not connected to each other.

[0071] 5. The reaction tube one 1 is wrapped with an electric heating belt and an aluminum foil, and the reaction tube one 1 is heated to accelerate the sublimation of the solid trioxane 7 in the reaction tube one 1; after reaching the set temperature, the multi-way valve 2 is adjusted to Figure 2 the state one as shown in the figure, and the bottle valve of the gas storage bottle 3 is opened, and the reaction is waited for 5 hours; during the process, the trioxane vapor obtained by sublimation flows through the multiple sets of reaction tube two 5 in sequence to perform a catalytic cracking reaction to generate formaldehyde gas, and the formaldehyde gas is collected by the gas storage bottle 3.

[0072] 6. After the reaction, the second valve port 22 is connected to the vacuum molecular pump group (including a mechanical pump and a molecular pump), and the pipeline is pumped to 10 -6 hPa. Then the second valve port 22 is connected to the carrier gas delivery pipeline 42, and the multi-way valve 2 is adjusted to Figure 3 the state two as shown in the figure (that is, the third valve port 23 and the second valve port 22 are connected), and the carrier gas system 4 slowly blows high-purity N2 (or other dilution gas) into the multi-way valve 2 and the multiple sets of reaction tube two 5 until the bottle valve is closed and the blowing is stopped when the target pressure (such as 10 bar) is reached in the gas storage bottle 3.

[0073] 7. The reactor is disassembled, and the mass m1 of the experimental reactor is weighed and recorded. The actual transferred mass of trioxane is m=m0-m1.

[0074] 8. The gas storage bottle 3 is cooled and weighed to obtain the mass M1, and the mass M of the added nitrogen in the gas storage bottle 3 is M=M1-M0-m, and the concentration of the formaldehyde in the bottle is calculated. The formaldehyde gas standard substance generation device 100 of the present scheme collects the formaldehyde gas by using the pressure difference and carrier gas blowing, and collects the formaldehyde gas by using the gas bottle, thereby realizing the preparation of the formaldehyde bottled gas.

[0075] The formaldehyde gas molecule has a lively property, and in the preparation and storage process in the gas bottle, it is easy to have behaviors such as adsorption and reaction in the pipeline, which brings great challenges to the accurate value and stable preservation of the formaldehyde bottled gas standard substance. Based on this, the present scheme is provided with a passivation coating in the gas storage bottle 3 and the formaldehyde delivery pipeline 6. The pipeline coating can be selected from the silicon passivation pipeline of SilcoTek company in the United States, and the pipeline is passivated by technology; and the gas storage bottle 3 can be a PW type coating gas bottle produced by Fushun Jieneng Technology Co., Ltd. which has a passivation coating.

[0076] It is to be understood that the structures, proportions, sizes, etc. shown in the drawings of the present application are merely used to cooperate with the disclosed content, to be understood and read by those skilled in the art, and are not used to limit the implementation conditions of the present application, so they do not have substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in the present application are only for clear description, and are not used to limit the scope of the present application. The change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the scope of the present application.

[0077] The principles and implementation modes of the present application are described by applying specific examples in the present application. The above examples are only used to help understand the method and core idea of the present application. Meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In conclusion, the content of the present application should not be understood as a limitation of the present application.

Claims

1. A device for generating a bottled formaldehyde gas standard substance, characterized in that, The application relates to a device for preparing a formaldehyde gas standard substance, comprising: a sublimation device, which is used for at least containing solid trioxane (7) to sublimate the solid trioxane (7) to generate trioxane vapor; a catalytic cracking device, which is used for at least containing a cracking catalyst (8) and is used for catalytically cracking the trioxane vapor generated by the sublimation device to generate formaldehyde gas; a gas storage cylinder (3) connected with the catalytic cracking device and capable of collecting the formaldehyde gas; a carrier gas system (4) connected with the gas storage cylinder (3) and used for diluting the formaldehyde gas in the gas storage cylinder (3) to prepare a formaldehyde cylinder gas standard substance in the gas storage cylinder (3).

2. The apparatus for generating a formaldehyde-bottled gas standard according to claim 1, wherein The sublimation device comprises: a first reaction tube (1) used for containing the solid trioxane (7) and a drying agent (11) for drying the solid trioxane (7); a multi-way valve (2) comprising at least a first valve port (21), a second valve port (22) and a third valve port (23), wherein the first valve port (21) is connected with a gas outlet of the first reaction tube (1), the second valve port (22) and the third valve port (23) are respectively connected with the carrier gas system (4) and the catalytic cracking device, and the multi-way valve (2) can control the third valve port (23) to communicate with the first valve port (21) or the second valve port (22).

3. The apparatus for generating a formaldehyde-bottled gas standard according to claim 2, wherein The sublimation device further comprises a passivated quartz wool (9) which is detachably arranged at the gas outlet end of the first reaction tube (1).

4. The apparatus for generating a formaldehyde-bottled gas standard according to claim 2, wherein The sublimation device further comprises a first heating device, which comprises at least one of an electric heating wire and an electric heating belt, and at least one of the electric heating wire and the electric heating belt is wound outside the first reaction tube (1).

5. The apparatus for generating a formaldehyde gas standard according to any one of claims 2 to 4, wherein The catalytic cracking device comprises a second reaction tube (5) used for at least containing the cracking catalyst (8) and a second heating device comprising at least one of an electric heating wire and an electric heating belt, and at least one of the electric heating wire and the electric heating belt is wound outside the second reaction tube (5).

6. The apparatus for generating a formaldehyde-bottled gas standard according to claim 5, wherein The second heating device further comprises a heat preservation layer wrapped outside the electric heating wire and / or the electric heating belt.

7. The apparatus for generating a formaldehyde-bottled gas standard according to claim 5, wherein The catalytic cracking device comprises a plurality of second reaction tubes (5) connected in series through a formaldehyde delivery pipeline (6), wherein the first end of the second reaction tube (5) is connected with the third valve port (23) through the formaldehyde delivery pipeline (6), and the last end of the second reaction tube (5) is connected with the gas storage cylinder (3) through the formaldehyde delivery pipeline (6).

8. The apparatus for generating a formaldehyde-bottled gas standard according to claim 7, wherein The inner wall of the gas storage cylinder (3) and / or the inner wall of the formaldehyde delivery pipeline (6) is provided with a passivation coating.

9. The apparatus for generating a formaldehyde-bottled gas standard according to claim 7, wherein The inner diameter of the first formaldehyde delivery pipeline is not less than the inner diameter of the second formaldehyde delivery pipeline, and the inner diameter of the second formaldehyde delivery pipeline is greater than the inner diameter of the third formaldehyde delivery pipeline, wherein the first formaldehyde delivery pipeline is the formaldehyde delivery pipeline (6) between the reaction tube two (5) at the front end and the third valve port (23), the second formaldehyde delivery pipeline is the formaldehyde delivery pipeline (6) between the two reaction tube two (5), and the third formaldehyde delivery pipeline is the formaldehyde delivery pipeline (6) between the reaction tube two (5) at the tail end and the gas storage bottle (3).

10. The apparatus for generating a formaldehyde gas standard according to any one of claims 2 to 4, wherein The carrier gas system (4) comprises a carrier gas bottle (41) and a carrier gas delivery pipeline (42), and the carrier gas bottle (41) is connected with the second valve port (22) through the carrier gas delivery pipeline (42).

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