A pipe device for mass spectrometric online collection of gas phase components in off-gas

Abstract

The present application relates to the technical field of online mass spectrum detection, and particularly relates to a pipeline device for collecting gas phase components in tail gas by online mass spectrum. The pipeline device comprises a detection pipeline, a gas extraction pipeline and a quartz capillary, the detection pipeline and the gas extraction pipeline are communicated, a diaphragm pump is arranged on the gas extraction pipeline, tail gas in the detection pipeline is extracted by the diaphragm pump, the gas flow rate in the detection pipeline is accelerated, a powder sintered filter head is arranged at the sampling head of the detection pipeline, a filter is arranged in the middle part of the detection pipeline, and particulate matter with a cross section greater than 1 um is intercepted; meanwhile, an electric resistance wire heating layer and a temperature insulation layer are sequentially arranged outside the detection pipeline, the temperature of the detection pipeline is controlled to be lower than the pyrolysis temperature of the detected substance, and the pollution problems such as pipeline blockage and solid particle tail gas condensation of the instrument can be prevented; therefore, the present application not only separates the distance between the high-precision detection mass spectrometer and the production line to be detected, but also does not cause the signal collected by the mass spectrometer to decrease, and trace detection of the species concerned in the process of collecting the gas phase components of the tail gas is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of online mass spectrometry, and in particular to a pipeline device for online mass spectrometry collection of gas phase components in tail gas. BACKGROUND

[0002] With the development of the times, in the production process of full-automatic production lines, unmanned workshops, etc., such as steel smelting, cigarette production, food production, and garbage treatment, a large amount of tail gas is discharged into the atmosphere during the production process. Due to the needs of environmental protection, product quality detection feedback, etc., it is necessary to detect and quantitatively analyze the tail gas online. Online real-time detection needs to be carried out at key production links to control the quality and content of tail gas, gas phase components in tail gas of various industries, and simultaneously collect quantitative data to better improve the process upgrading of production links.

[0003] Mass spectrometry can be used for online detection and quantitative analysis. Due to the diverse production line environment, high temperature, large particle dust pollution, and narrow space, etc., the high-precision detection mass spectrometer cannot be placed close to the production line. If the sampling pipeline is extended to separate the production line from the mass spectrometer, the mass spectrometer can be protected from the influence of the production line environment during online detection. However, extending the sampling pipeline will reduce the solid particle tail gas collection signal.

[0004] In the case of high-temperature, heating, and baking production lines, the sampling pipeline of the mass spectrometer also needs to be accompanied by the same temperature on the production line. Quartz capillary tubes are widely used in mass spectrometry sampling. They have the advantage of being resistant to high temperatures and can be placed at any angle with the pipeline. Due to the large amount of particulate matter in the tail gas, the mass spectrometry sampling capillary tube is easily clogged and has a small effective sampling amount, which cannot be used for trace detection of the species of interest in the process of collecting gas phase components in tail gas. SUMMARY

[0005] According to the problems in the background art, the present application provides a pipeline device for online mass spectrometry collection of gas phase components in tail gas. By setting a bypass diaphragm pump, the gas flow rate of the extended pipeline is assisted, and the sampling amount of the mass spectrometer for online collection of gas phase components in tail gas is enhanced.

[0006] The specific technical scheme of the present application is as follows: a pipeline device for online mass spectrometry collection of gas phase components in tail gas, comprising a detection pipeline 1, an air extraction pipeline 2, and a quartz capillary tube 3, and an electric resistance wire heating layer 11 and a temperature insulation layer 12 are sequentially arranged outside the detection pipeline 1;

[0007] A powder sintered filter head 13 is arranged at the gas inlet end of the detection pipeline 1, and a cavity entrance connecting mechanism 4 with heating function is arranged at the outlet end of the detection pipeline 1,

[0008] The filter 14 and the detection valve 15 are sequentially arranged between the gas inlet end and the outlet end of the detection pipeline 1,

[0009] The detection pipeline 1 corresponding to the detection valve 15 and the cavity connecting mechanism 4 is connected with the air suction end of the air suction pipeline 2 through the tee joint 16, the other end of the air suction pipeline 2 is connected with the diaphragm pump 21, and the air suction valve 22 is arranged on the air suction pipeline 2;

[0010] The quartz capillary tube 3 is arranged in the detection pipeline 1, and the collection end of the quartz capillary tube 3 is located in the detection pipeline 1 corresponding to the tee joint 16 and the detection valve 15, and the detection end of the quartz capillary tube 3 extends into the mass spectrometer through the cavity connecting mechanism 4;

[0011] In use, the powder sintering filter head 13 is arranged on the sample production line, the diaphragm pump 21, the detection valve 15 and the air suction valve 22 are opened, the cavity mechanism 4 heats the detection end of the quartz capillary tube 3, and the quartz capillary tube 3 collects the gas of the sample production line into the mass spectrometer for quantitative data analysis.

[0012] Further, the inner hole diameter of the quartz capillary tube 3 is 0.15 mm, and the collection end of the quartz capillary tube 3 is 30 mm away from the air suction end of the air suction pipeline 2;

[0013] The vacuum degree of the diaphragm pump 21 is 150 Mbar, and the air suction speed is 30 L / min.

[0014] Further, the filter 14 comprises a first pressing plate 141 and a second pressing plate 142, one side of the first pressing plate 141 is provided with a mounting boss, and a first taper groove is formed in the mounting boss,

[0015] One side of the second pressing plate 142 is provided with a mounting groove, and a second taper groove is formed in the groove bottom of the mounting groove,

[0016] The mounting boss and the mounting groove are matched and sealed by the O ring 143, so that the first pressing plate 141 and the second pressing plate 142 are fixed by bolts, and the first taper groove and the second taper groove are matched to form a mounting cavity, and the mounting cavity is provided with a filter paper 144,

[0017] The detection pipeline 1 is disconnected at the mounting cavity, and the two ends of the detection pipeline 1 are fixedly connected with the first pressing plate 141 and the second pressing plate 142, so that the gas in the detection pipeline 1 is filtered through the filter paper 144.

[0018] Further, the cavity connecting mechanism 4 comprises a cavity flange 41, a graphite taper sleeve 42 and a compression nut 43, the cavity flange 41 is fixed on the inlet end of the mass spectrometer by bolts and is sealed by a center support O ring 46;

[0019] The connecting end of the cavity flange 41 is provided with a flat cavity insertion plate 44, the quartz capillary tube 3 extends out of the detection pipeline 1 and penetrates through the cavity insertion plate 44, extends into the mass spectrometer, and the quartz capillary tube 3 is locked and fixed on the cavity insertion plate 44 through the cooperation of the graphite cone sleeve 42 and the compression nut 43 at the position corresponding to the cavity insertion plate 44.

[0020] Further, the thermocouple heating rod 45 is inserted on the cavity insertion plate 44, which is used for heating the detection end of the quartz capillary tube 3, so that the temperature of the detection end of the quartz capillary tube 3 is 40-250 DEG C.

[0021] The beneficial technical effects of the present application are as follows:

[0022] The pipeline device for online collection of gas phase components in tail gas by mass spectrometry provided by the present application comprises a detection pipeline, a gas suction pipeline and a quartz capillary tube, the detection pipeline and the gas suction pipeline are communicated, a diaphragm pump is arranged on the gas suction pipeline, tail gas suction of the detection pipeline is carried out through the diaphragm pump, the gas flow rate in the detection pipeline is accelerated, and then the collection of solid particle tail gas by the mass spectrometer is enhanced, a powder sintering filter head is designed at the sampling head of the detection pipeline, a filter is arranged in the middle part, and particles with a cross section greater than 1 um are intercepted, small molecules are still retained in the pipeline after being filtered by the filter paper, the effective acquisition of the capillary sampling end for the current product is effectively improved, and meanwhile, an electric resistance wire heating layer and a temperature insulation layer are sequentially arranged outside the detection pipeline, the temperature of the detection pipeline is controlled to be lower than the pyrolysis temperature of the detected substance, and the problems of pipeline blockage, solid particle tail gas condensation and other pollution problems can be prevented.

[0023] Therefore, the present application not only widens the distance between the high-precision detection mass spectrometer and the production line to be detected, but also does not cause the signal collected by the mass spectrometer to be reduced, and trace detection of the species concerned in the process of collecting the gas phase components of the tail gas is realized. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Fig. 1 is a structural schematic view of the pipeline device for online collection of gas phase components in tail gas by mass spectrometry provided by the present application.

[0025] Figure 2 Fig. 2 is a sectional view of the pipeline device for online collection of gas phase components in tail gas by mass spectrometry provided by the present application. Figure 1

[0026] Figure 3 Fig. 4 is a sectional view of the detection pipeline of the pipeline device for online collection of gas phase components in tail gas by mass spectrometry provided by the present application.

[0027] Figure 4 Fig. 6 is a structural schematic view of the filter of the pipeline device for online collection of gas phase components in tail gas by mass spectrometry provided by the present application.

[0028] Figure 5 Fig. 8 is a structural schematic view of the cavity insertion mechanism of the pipeline device for online collection of gas phase components in tail gas by mass spectrometry provided by the present application.

[0029] Figure 6 Fig. 10 is a position layout schematic view of the gas suction end of the quartz capillary tube and the gas suction pipeline of the pipeline device for online collection of gas phase components in tail gas by mass spectrometry provided by the present application.​

[0030] Figure 7 is a local enlarged view of Figure 6

[0031] Figure 8 is a detection data graph when the diaphragm pump and heating function of the pipeline device of the application are not started.

[0032] Figure 9 is a detection data graph when the diaphragm pump and heating function of the pipeline device of the application are started.

[0033] Wherein: the detection pipeline 1, the resistance wire heating layer 11, the temperature insulation layer 12, the powder sintering filter head 13, the filter 14, the first pressing plate 141, the second pressing plate 142, the O-ring 143, the filter paper 144, the detection valve 15, the three-way pipe 16, the air extraction pipeline 2, the diaphragm pump 21, the air extraction valve 22, the quartz capillary tube 3, the cavity entry connecting mechanism 4, the cavity entry flange 41, the graphite cone sleeve 42, the compression nut 43, the cavity entry plug 44, and the thermocouple heating rod 45. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the application more clear and understandable, the application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the application and not to limit the application. EXAMPLE

[0035] In the process of cigarette production, the tobacco is often treated by processes such as moisture recovery, temperature increase and drying. After each process, the internal chemical composition of the tobacco will change in a series of ways, and will also be accompanied by the loss of chemical composition. Moreover, the changes in process route and process parameters often lead to different changes and losses of chemical composition, which in turn cause changes in the quality of the cigarette product. Scientific and reasonable setting of the cigarette production process route, process parameters and ensuring the stability of the entire production process.

[0036] Therefore, the pipeline device for online collection of gas phase components in tail gas by mass spectrometry is applied in online air extraction detection of cut tobacco tail gas in a cigarette factory.

[0037] See Figure 1 and Figure 2 A pipeline device for online collection of gas phase components in tail gas by mass spectrometry, comprising a detection pipeline 1, an air extraction pipeline 2 and a quartz capillary tube 3, see Figure 3 The detection pipeline 1 is provided with a resistance wire heating layer 11 and a temperature insulation layer 12 in sequence outside.

[0038] The air inlet end of the detection pipeline 1 is provided with a powder sintering filter head 13, and the outlet end of the detection pipeline 1 is provided with a cavity entry connecting mechanism 4 with heating function, ​

[0039] The filter 14 and the detection valve 15 are sequentially arranged between the gas inlet end and the outlet end of the detection pipeline 1, that is, the gas inlet end of the detection pipeline 1 collects the cut tobacco tail gas of the cigarette factory.

[0040] The detection pipeline 1 corresponding to the detection valve 15 and the cavity connecting mechanism 4 is connected with the air suction end of the air suction pipeline 2 through the tee joint 16, the other end of the air suction pipeline 2 is connected with the diaphragm pump 21, and the air suction valve 22 is arranged on the air suction pipeline 2;

[0041] The quartz capillary tube 3 is arranged in the detection pipeline 1, and the collection end of the quartz capillary tube 3 is located in the detection pipeline 1 corresponding to the tee joint 16 and the detection valve 15, and the detection end of the quartz capillary tube 3 extends into the mass spectrometer through the cavity connecting mechanism 4;

[0042] In use, the powder sintering filter head 13 is arranged on the sample production line, the diaphragm pump 21, the detection valve 15 and the air suction valve 22 are turned on, the cavity connecting mechanism 4 heats the detection end of the quartz capillary tube 3, and the quartz capillary tube 3 collects the gas of the sample production line into the mass spectrometer for quantitative data analysis.

[0043] See Figure 6 and Figure 7 , the inner hole diameter of the quartz capillary tube 3 is 0.15 mm, and the collection end of the quartz capillary tube 3 is 30 mm away from the air suction end of the air suction pipeline 2; the vacuum degree of the diaphragm pump 21 is 150 Mbar, and the air suction speed is 30 L / min; under the action of the diaphragm pump 21, the gas flow rate of the detection pipeline 1 is accelerated, and the mass spectrometer collects the solid particle tail gas.

[0044] See Figure 4 , the filter 14 includes a first pressing plate 141 and a second pressing plate 142, one side of the first pressing plate 141 is provided with a mounting boss, and a first taper groove is formed in the mounting boss;

[0045] A mounting groove is formed in one side of the second pressing plate 142, and a second taper groove is formed in the groove bottom of the mounting groove;

[0046] The mounting boss and the mounting groove are matched and sealed through the O-ring 143, so that the first pressing plate 141 and the second pressing plate 142 are fixed and locked through bolts, the first taper groove and the second taper groove are matched to form a mounting cavity, and the mounting cavity is provided with a filter paper 144;

[0047] The detection pipeline 1 is disconnected at the mounting cavity, and the two ends of the disconnected detection pipeline 1 are fixedly connected with the first pressing plate 141 and the second pressing plate 142, so that the gas in the detection pipeline 1 is filtered through the filter paper 144.

[0048] The powder sintering filter head 13 and the filter 14 are arranged to trap particles with a cross section greater than 1 um, and small molecules are filtered through the filter paper 144 and still remain in the detection pipeline 1, so that the effective acquisition of the current product by the sampling end of the quartz capillary 3 is improved.

[0049] See Figure 5 The cavity inlet connecting mechanism 4 comprises a cavity inlet flange 41, a graphite cone sleeve 42 and a compression nut 43, the cavity inlet flange 41 is fixed on the inlet end of the mass spectrometer through bolts and is sealed through a center support O ring 46.

[0050] The connecting end of the cavity inlet flange 41 is provided with a flat cavity inlet plug-in plate 44, the quartz capillary 3 extends out of the detection pipeline 1 and penetrates through the cavity inlet plug-in plate 44 and extends into the mass spectrometer.

[0051] The quartz capillary 3 is locked and fixed on the cavity inlet plug-in plate 44 through the cooperation of the graphite cone sleeve 42 and the compression nut 43 at the position corresponding to the cavity inlet plug-in plate 44, a thermocouple heating rod 45 is inserted on the cavity inlet plug-in plate 44 and is used for heating the end cavity of the quartz capillary 3, so that the temperature of the detection end of the quartz capillary 3 is 40 DEG C ~ 250 DEG C.

[0052] In combination with the arrangement of the resistance wire heating layer 11 and the temperature insulation layer 12, the temperature of the detection pipeline 1 can be controlled to be lower than the pyrolysis temperature of the detected substance, so that the pollution problems such as pipeline blockage and solid particle tail gas condensation of the instrument pipeline can be prevented.

[0053] The pipeline device for on-line collection of gas phase components in tail gas of mass spectrometry is applied to on-line air extraction detection of cut tobacco baking tail gas in a cigarette factory, Figure 8 , Figure 9 The experimental comparison graph.

[0054] Specifically, as shown in Figure 8 The detection of the mass spectrometry pipeline device shows that the cut tobacco baking tail gas in the cigarette factory contains water, nitrogen and oxygen, and the signal intensity of other species is almost zero, the diaphragm pump 21 of the pipeline device is not started, and the heating is not started, so that the tail gas emission of cut tobacco baking nicotine in the cigarette factory cannot be measured, but this does not mean that the cut tobacco baking process link in the cigarette factory does not release nicotine and other tail gas, only because the detection pipeline 1 is too long, and the solid particle tail gas condensation in the tail gas cannot normally enter the mass spectrometer.

[0055] From the detection data trend, the on-line monitoring of water, nitrogen and oxygen in the period of 11:15:00-17:35:00 has a signal intensity attenuation phenomenon, which can be analyzed that the sampling pipeline of the mass spectrometer may be blocked due to the condensation of some solid particle tail gas.

[0056] Therefore, in order to confirm whether there is a trace species release, the pipe device of the present application must be set up in the cigarette factory cut tobacco production process, the temperature close to the cigarette factory cut tobacco production process is set, the conditions are similar, under the action of the pipe temperature, the tail gas released by the cigarette cut tobacco does not condense, at the same time, the suction and collection speed is improved, the cigarette cut tobacco production tail gas quickly enters the mass spectrometer for detection and analysis, as shown in Figure 9 When the pipe device diaphragm pump 12 is started and the pipe device heating is started, the cigarette factory cut tobacco nicotine tail gas emission can be obviously detected, the cigarette factory cut tobacco tail gas contains water, nitrogen, oxygen, nicotine and other species, at the same time, the water, nitrogen and oxygen signal intensity is obviously enhanced by 1 times, this series of changes are caused by the pipe device diaphragm pump 12 suction of the gas phase components in the tail gas, pipe heating and insulation. Further, it is explained that the cigarette factory has released nicotine in the air in the tobacco cutting link, the content of the measured tail gas release is further analyzed, and the tobacco production baking temperature parameters and process are better improved in the future.

[0057] Therefore, the present application not only widens the distance between the high-precision detection mass spectrometer and the production line to be detected, but also does not cause the signal collected by the mass spectrometer to decrease, realizes trace detection of the species concerned in the gas phase component process of the collected tail gas. The photoionization time-of-flight mass spectrometer is better applied to the main component analysis of the key process of the cut tobacco process, a variety of tobacco internal chemical component online detection system is developed, a neural source network of multi-process online detection, multi-component linkage and man-machine interaction is formed, the influence law of the key parameters in the tobacco production process is clarified, and an effective detection means and customized scheme are further provided for perfecting the process flow and optimizing the best process parameters.

[0058] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A pipeline device for online collection of gas phase components in tail gas by mass spectrometry, characterized in that: it comprises a detection pipeline (1), a suction pipeline (2) and a quartz capillary (3), and the detection pipeline (1) is sequentially provided outside with a resistance wire heating layer (11) and a temperature insulation layer (12); the gas inlet end of the detection pipeline (1) is provided with a powder sintered filter head (13), and the gas outlet end of the detection pipeline (1) is provided with a cavity inlet connecting mechanism (4) with heating function; the gas inlet end and the gas outlet end of the detection pipeline (1) are sequentially provided with a filter (14) and a detection valve (15); the detection valve (15) and the cavity inlet connecting mechanism (4) are connected with the suction end of the suction pipeline (2) through a tee joint (16), the other end of the suction pipeline (2) is connected with a diaphragm pump (21), and the suction pipeline (2) is provided with a suction valve (22); the quartz capillary (3) is arranged in the detection pipeline (1), and the collection end of the quartz capillary (3) is located in the detection pipeline (1) between the tee joint (16) and the detection valve (15), and the detection end of the quartz capillary (3) extends into the mass spectrometer through the cavity inlet connecting mechanism (4); in use, the powder sintered filter head (13) is arranged on a sample production line, the diaphragm pump (21), the detection valve (15) and the suction valve (22) are turned on, the detection end of the quartz capillary (3) is heated by the cavity inlet connecting mechanism (4), and the quartz capillary (3) collects the gas of the sample production line and quantitatively analyzes the data in the mass spectrometer. The inner hole diameter of the quartz capillary (3) is 0.15 mm, and the collection end of the quartz capillary (3) is 30 mm away from the suction end of the suction pipeline (2). The vacuum degree of the diaphragm pump (21) is 150 Mbar, and the suction speed is 30 L / min. The filter (14) comprises a first pressing plate (141) and a second pressing plate (142), the first pressing plate (141) is provided on one side with a mounting boss, and the mounting boss is provided with a first taper groove, the second pressing plate (142) is provided on one side with a mounting groove, and the groove bottom of the mounting groove is provided with a second taper groove, the mounting boss and the mounting groove are matched and sealed by an O ring (143), so that the first pressing plate (141) and the second pressing plate (142) are fixed by bolts, the first taper groove and the second taper groove are matched to form a mounting cavity, and the mounting cavity is provided with filter paper (144), the detection pipeline (1) is disconnected at the mounting cavity, and the two ends of the disconnected detection pipeline (1) are fixedly connected with the first pressing plate (141) and the second pressing plate (142), so that the gas in the detection pipeline (1) is filtered by the filter paper (144).

2. The conduit device for online collection of gas phase components in tail gas by mass spectrometry according to claim 1, characterized in that: The cavity inlet connecting mechanism (4) comprises a cavity inlet flange (41), a graphite taper sleeve (42) and a compression nut (43), the cavity inlet flange (41) is fixed on the inlet end of the mass spectrometer by bolts and is sealed by a center support O ring (46); the connecting end of the cavity inlet flange (41) is provided with a flat cavity inlet plug-in plate (44), the quartz capillary (3) extends out of the detection pipeline (1) and penetrates through the cavity inlet plug-in plate (44) to extend into the mass spectrometer, ​ 3. The conduit device for online collection of gas phase components in tail gas by mass spectrometry according to claim 1, characterized in that: ​ ​ ​ ​ 4. The conduit device for online collection of gas phase components in tail gas by mass spectrometry according to claim 1, characterized in that: ​ ​ The quartz capillary (3) is locked and fixed on the cavity-inserting plate (44) through the cooperation of the graphite cone sleeve (42) and the compression nut (43) corresponding to the cavity-inserting plate (44).

5. The conduit device for online collection of gas phase components in tail gas by mass spectrometry according to claim 4, characterized in that: The thermocouple heating rod (45) is inserted on the cavity-inserting plate (44) and used for heating the detection end of the quartz capillary (3), so that the temperature of the detection end of the quartz capillary (3) is 40℃-250℃.

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