CN207764177U - A kind of countryside portable gas-detecting device - Google Patents

Abstract

The utility model proposes a kind of countryside portable gas-detecting device, including babinet, babinet is provided with gas sampling unit, and the babinet is internally provided with gas separation unit, detection unit, data acquisition and processing unit, control unit and carrier gas unit；Wherein, the gas separation unit is arranged in an independent separator box, and the separator box is provided with three air inlet pipe and three exhaust pipes of its inside of connection.The countryside portable gas-detecting device of the utility model provides the overall structure being integrated in built in whole in babinet, easy to carry and transport, and the emergent gas analysis for being suitable for various wild environments detects.The gas separation unit of absolute construction can facilitate to form the highly integrated gas analyzer for facilitating exchange, reduce the quantity of connecting pipe and the quantity of control valve, can effectively reduce systematic error, improve the accuracy of detection and reliability of system.

Description

Open-air portable gaseous detection device

Technical Field

The utility model belongs to the technical field of environmental protection's gaseous detection and analysis technique and specifically relates to a can be used to detect detection device, especially a field portable gaseous detection device of gaseous composition.

Background

The environmental protection field often needs to detect and analyze various gases, and a gas chromatograph is generally used. The gas chromatograph is a device for analyzing and detecting a mixed sample, and generally comprises a gas path system, a sample introduction system, a separation system, a circuit control system, a detection system, a data acquisition and processing system and the like. However, the existing gas chromatograph is generally installed in a laboratory, the whole volume is very large, complicated airflow pipelines and various power supply and control cables and the like need to be connected among systems, the connection reliability of the whole device is very unstable, the calibration needs to be checked again when the system is changed slightly, and the possibility of carrying conveniently does not exist basically.

CN 106841483 a discloses a chromatographic sample feeding separation device, which is combined by an eight-way valve and a ten-way valve to improve the analysis efficiency. However, the two sets of valves are only half the time to utilize half of the gas paths, and the two sets of gas paths are not related to each other. As a result, systematic errors are easily caused by the difference between the two sets of air passages, for example, the volume difference of the two quantitative pipes inevitably exists, so that the inevitable systematic errors exist. And more gas circuit pipelines need a large amount of connecting pipelines, the more pipelines, the larger the error brought by the volume of the gas circuit, and the larger the adsorption influence of pipeline materials on components in the gas. In addition, the more pipes, the more easily the joints are subjected to connection failure, the time for calibrating and troubleshooting is greatly increased, and the reliability of the system is deteriorated. The use of the two sets of valves brings the problem of synchronism, the control conversion of the system is complex, the volume occupied by the two sets of valves is larger, and the two sets of valves are difficult to be used for portable emergency sampling analysis.

CN 104374860 a discloses a portable gas analyzer, which adopts a single ten-way valve in cooperation with two chromatographic columns to perform post-separation analysis on gas. However, the introduction of the whole frame of the portable gas analyzer in the prior art is very crude, and only the description includes a box body, an automatic sampling and sampling mechanism, a sample gas separation mechanism and a chromatographic detection mechanism are arranged in the box body, the automatic sampling and sampling mechanism includes a ten-way valve and a sampling ring, the mixed gas separation mechanism mainly includes a coarse chromatographic column, a fine chromatographic column, an auxiliary pipeline and heat insulation cotton, and the mixed gas detection mechanism mainly includes a fuel cell and an auxiliary pipeline. No description is given as to the delivery of gas, calibration of the apparatus, control of the apparatus, etc., and the person skilled in the art cannot imagine the overall structure of the portable gas analyzer of the prior art. In addition, this prior art adopts two chromatographic columns mode of ally oneself with to carry out the separation of gas, gets rid of the influence of impurity through the mode of establishing ties, and two chromatographic columns keep the continuity to establish ties during the use, and a state sampling adds the washing pipeline, and a state advances a kind analysis. However, the dual chromatographic columns of the prior art are continuously used in series, and only the species of the target section can be selectively highlighted according to two columns, so that the rest sections are omitted, but the prior art cannot remove interfering substances, cannot pull and amplify the peak patterns of different components in trace gas, the peak patterns of the species of the target section are not sufficiently subdivided, and the accuracy of the analysis result is still to be improved.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a portable gas detection device in field to reduce or avoid the aforementioned problem.

Particularly, the utility model provides a field portable gas detection device, it can effectively reduce system error, improves system reliability and detection precision to can be more practical and portable.

In order to solve the technical problem, the utility model provides a field portable gas detection device, which comprises a box body, wherein the box body is provided with a gas sampling unit, and a gas separation unit, a detection unit, a data acquisition and processing unit, a control unit and a carrier gas unit are arranged inside the box body; the gas separation unit is arranged in an independent separation box, and the separation box is provided with three gas inlet pipes and three gas outlet pipes communicated with the interior of the separation box; the three gas inlet pipes are respectively a first gas inlet pipe and a second gas inlet pipe which are communicated with the carrier gas unit, and a third gas inlet pipe which is communicated with the gas sampling unit; the three exhaust pipes are respectively a first exhaust pipe and a second exhaust pipe for emptying, and a third exhaust pipe communicated with the detection unit.

Preferably, the data acquisition and processing unit is connected with the detection unit through a circuit.

Preferably, the carrier gas unit comprises a carrier gas steel cylinder, and the carrier gas steel cylinder provides the first path of carrier gas and the second path of carrier gas through the first gas inlet pipe and the second gas inlet pipe respectively.

Preferably, the gas separation unit includes a ten-way valve provided inside the separation tank, the ten-way valve having first to tenth connection ports numbered in order of adjoining positions; the first connecting port is communicated with the eighth connecting port through a pipeline provided with a first chromatographic column; the second connecting port is communicated with the third exhaust pipe, and the third exhaust pipe is provided with a second chromatographic column positioned between the second connecting port and the detection unit; the third connecting port is communicated with the second air inlet pipe; the fourth connecting port is communicated with the seventh connecting port through a pipeline provided with a quantitative pipe; the fifth connecting port is communicated with the second exhaust pipe; the sixth connecting port is communicated with the third air inlet pipe; the ninth connecting port is communicated with the first exhaust pipe; the tenth connection port is communicated with the first intake pipe.

Preferably, the ten-way valve has a first state in which the first connection port communicates with the tenth connection port, the second connection port communicates with the third connection port, the fourth connection port communicates with the fifth connection port, the sixth connection port communicates with the seventh connection port, and the eighth connection port communicates with the ninth connection port.

Preferably, the ten-way valve has a second state in which the first connection port communicates with the second connection port, the third connection port communicates with the fourth connection port, the fifth connection port communicates with the sixth connection port, the seventh connection port communicates with the eighth connection port, and the ninth connection port communicates with the tenth connection port.

Preferably, the ten-way valve has a third state in which the ten-way valve is connected in the same relationship as the first state.

The utility model discloses a portable gaseous detection device in field provides whole built-in integrated overall structure in the box, and each structure is stable connection as an organic whole in the box, compact structure, portable and transportation are applicable to the emergent gaseous analysis of various field environment and detect. And the gas separation unit with an independent structure can conveniently form a highly integrated gas analyzer which can be conveniently exchanged, and the number of connecting pipelines and the number of control valves are reduced, so that the system error can be effectively reduced, and the reliability and the detection precision of the system are improved. Additionally, the utility model discloses a gaseous back flushing of holding back of gaseous miscellaneous peak that will resolve after through first chromatographic column of gas separation unit is favorable to waiting to examine the improvement of gaseous detection precision, later pulls open the crest interval of each composition through the second chromatographic column, has improved the detection degree of different compositions especially trace composition, has improved the detection precision.

Drawings

The drawings are only intended to illustrate and explain the present invention and do not limit the scope of the invention. Wherein,

FIG. 1 is a schematic diagram of a field portable gas detection device according to an embodiment of the present invention;

FIG. 2 is a schematic diagram showing the connection structure of a field portable gas detection device according to another embodiment of the present invention;

FIG. 3 is a schematic diagram showing first and third states of a gas separation unit of a field portable gas detection apparatus according to yet another embodiment of the present invention;

fig. 4 shows a schematic view of a second state of the gas separation unit of fig. 3.

Detailed Description

In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described with reference to the accompanying drawings. Wherein like parts are given like reference numerals.

As described in the background section, the conventional gas analyzing apparatus, such as a gas chromatograph, has a complicated structure and many connecting pipes, power supply cables, control cables, etc., which results in poor stability and inconvenience in carrying. Therefore, the utility model provides a field portable gas detection device through simplifying the structure, with necessary structure integration as far as possible together, reduces connecting tube's quantity and control flap's quantity through reducing the part quantity of piece-rate system as far as possible to can effectively reduce system error, improve gas analyzer's detection precision when improving the reliability, with the field portable gas detection device who obtains a more practical.

Specifically, referring to fig. 1, which shows a schematic structural diagram of a portable gas detection device in the field according to an embodiment of the present invention, the portable gas detection device in the field includes a box 100, the box 100 is provided with a gas sampling unit 11, and a gas separation unit 12, a detection unit 13, a data acquisition and processing unit 14, a control unit 15, a carrier gas unit 16 and a calibration unit 17 are arranged inside the box 100; in addition, according to the needs of the pressure condition of the sampling air source, the utility model discloses a field portable gas detection device can also embed the sampling pump 18 by the control unit 15 control in box 100. The outer side of the box 100 may also be provided with a terminal for an external power line, or the terminal of the external power source may be replaced with a USB power supply connector (not shown in the figure) for connecting to a vehicle-mounted power source, which is also an alternative feasible solution. Of course, in a particularly compact and portable configuration, a battery may also be built into the case 100 for emergency testing.

In addition, in the specific structure of the utility model, as shown in fig. 2, it shows that according to the utility model discloses a connection structure schematic diagram of open-air portable gas detection device of another embodiment, see fig. 1-2, still be provided with various cables, solenoid valve isotructures of connecting data acquisition and processing unit 14, the control unit 15 in the box 100, corresponding also has the gaseous duct isotructure that feeds through gaseous introduction unit 11, gas separation unit 12, detecting element 13, carrier gas unit 16 and calibration unit 17.

In addition, the utility model discloses a still embed gas separation unit 12 that has independent structure among the portable gas detection device in open-air, it sets up in an independent separator box 120, separator box 120 is provided with its inside three intake pipe 121 of intercommunication, 122, 123 and three blast pipe 124, 125, 126. That is, the gas separation unit 12 disposed in the box 100 is designed as an independent structure, there are only six pipes connecting the inside and the outside of the separation box 120, namely, three inlet pipes 121, 122, 123 and three outlet pipes 124, 125, 126, and the inside of the separation box 120 is integrated with a gas phase separation column suitable for separating a specific kind of gas, for example, for the separation detection of aromatic hydrocarbon compounds, such as-502.2 metal capillary column in combination with a gas phase separation column of the CP-Sil 43CB type; or for separate detection of halogenated compounds, for example-502.2 metal capillary column and gas phase separation column of ae.ov-1301 type. WhereinThe series of metal capillary columns, CP-Sil 43CB and AE.OV-1301 are commercially available gas phase components of common typesThe gas analysis performance of the off-column model can be obtained by inquiring various product manuals. In addition, a constant temperature control mechanism can be further arranged in the separation box 120 to avoid the interference of the room temperature fluctuation with the analysis result.

The gas separation unit 12 with an independent structure can form a highly integrated and conveniently interchangeable gas analyzer, that is, for the detection of the separation of gases of different types, the gas separation boxes 120 of various specifications can be prefabricated, when a certain type of gas needs to be analyzed, the gas separation boxes 120 of corresponding types can be installed in the box body 100, and the gas analyzer of one type can be correspondingly formed only by six pipelines which are communicated with the internal pipeline of the box body 100 and are communicated with the gas separation boxes 120. In fact, in the embodiment shown in fig. 2, the six pipes of the gas separation box 120, in fact, with the two evacuation pipes 124 and 126 for emptying, are directly discharged outside the box 100, i.e. the two pipes 124 and 126 are integrated in the gas separation box 120, and when being installed in the box 100, there is no need for any joints at all, so that only four pipe joints are needed for replacing one gas separation box 120.

Correspondingly, at a suitable position of the box 100, an air inlet pipe of the gas sample injection unit 11 and a channel for exhausting air from the three air outlet pipes 124, 125, 126 may be provided. In addition, according to the specific situation of the sampled gas, in order to facilitate gas analysis, a filter joint 111 for preliminary dehumidification and dust removal may be disposed on the gas inlet pipe of the gas sampling unit 11; of course, in an environment where the gas source is dry and dust-free, the gas may be directly filtered by the dust removing structure built in the gas sampling unit 11 without the filter joint 111.

That is, can see from fig. 1-2, the utility model discloses a portable gaseous detection device in field can provide the overall structure of whole built-in integrations in the box, and each structure is as an organic whole at the stable connection of box, compact structure, portable and transportation are applicable to the emergent gaseous analysis detection of various field environment. And the gas separation unit with an independent structure can conveniently form a highly integrated gas analyzer which can be conveniently exchanged, and the number of connecting pipelines and the number of control valves are reduced, so that the system error can be effectively reduced, and the reliability and the detection precision of the system are improved.

Further, the data collecting and processing unit 14 shown in fig. 1-2 is electrically connected to the detecting unit 13, and the data collecting and processing unit 14 has a display screen 141 for displaying the detection result and at least one data output interface 142. Three USB-type data output interfaces 142 are shown in detail in fig. 1, wherein one data output interface 142 may also be provided in the form of a card reader adapted to mount a memory card. The display 141 may be a liquid crystal display (lcd) embedded in one side of the casing 100, or may be only a video output interface, and may be connected to an external display by means of a video cable. Or, in another embodiment, according to the state of the art, the display screen 141 and the data output interface 142 may be combined into a unified and independent interface, such as a USB Type-C interface, through which an external notebook computer may be connected to receive the detection data and/or the video signal, which has better scalability.

In addition, as shown in fig. 2, the three gas inlet pipes 121, 122, 123 are a first gas inlet pipe 121 and a second gas inlet pipe 122 respectively communicated with the carrier gas unit 16, and a third gas inlet pipe 123 communicated with the gas sampling unit 11 and the calibration unit 17.

In addition, the three exhaust pipes 124, 125, 126 are a first exhaust pipe 124 and a second exhaust pipe 125 for evacuation, respectively, and a third exhaust pipe 126 communicating with the detection unit 13.

Further, the carrier gas unit 16 may include a carrier gas cylinder 161 disposed in the box 100, and the carrier gas cylinder 161 provides the first carrier gas and the second carrier gas through the first inlet pipe 121 and the second inlet pipe 122, respectively. That is, in the present embodiment, the carrier gas cylinder 161 is built in, so that the trouble of connecting gas cylinders on site can be reduced, the system error is reduced, the redundant calibration process after temporary connection is avoided, and the method is particularly suitable for gas analysis and detection in emergency situations, such as toxic gas leakage situations. In addition, two paths of carrier gas are provided by a single carrier gas steel cylinder 161, so that system errors such as flow and components of different gas sources are avoided, and the detection precision is improved. Of course, in view of portability, the amount of carrier gas in the built-in carrier gas cylinder 161 is limited, and the housing 100 may be provided with an interface connected in parallel with the carrier gas cylinder 161 for externally connecting another high-ballast gas cylinder during a long-time field test. Since the flow rate and the type selection of the carrier gas have a great influence on the result, the external carrier gas source needs to be replaced and calibration needs to be performed again, and the calibration process will be further described below.

Further, the calibration unit 17 includes a calibration steel cylinder 171 and a dynamic calibration instrument 172 built in the housing 100, and the third gas inlet pipe 123 communicates the calibration steel cylinder 171 and the dynamic calibration instrument 172 through a three-way valve. Similarly, the calibration steel cylinder 171 is arranged in the gas cylinder calibration device, so that the trouble of connecting the gas cylinder on site can be reduced, and the system error is reduced. With the calibration cylinder 171, a quick calibration can be performed, that is, by collecting a standard mixed gas with a known concentration in the calibration cylinder 171 into the quantitative tube 203, performing a normal separation detection procedure to obtain the component peaks of each component, and comparing the quantitative data such as the peak height and the peak area with a standard curve of a laboratory to determine whether the system state meets formal measurement.

In addition, the dynamic calibration instrument 172 in the calibration unit 17 may perform a multi-point dynamic calibration process. That is, the dynamic calibration instrument 172 is a multi-point calibration instrument, and after the dynamic calibration instrument 172 is used to prepare mixed gas with different known concentrations and detect the mixed gas to obtain an analysis result, a plurality of points are obtained by plotting the concentrations of the different gases and quantitative values (peak heights or peak areas), and a standard curve can be obtained from the points. Typically, when taken out of the field for testing, the dynamic calibration apparatus 172 may not be connected to the housing, but the calibration cylinder 171 may remain continuously connected, i.e., built into the housing. If the detection time is too long, a high-pressure gas cylinder with large capacity of standard gas can be externally connected. The calibration cylinder 171 is only of fixed concentration, i.e. only corresponds to a point on the standard curve obtained by the dynamic calibration instrument 172, and the operating state of the instrument can be known from the deviation of the point from the curve, so that the calibration is called fast calibration or also called fast verification. This fast calibration system can be performed at the beginning or near the end of a field test, or it can be programmed to perform 1-2 fast calibrations periodically by the control system 15 each day.

In one embodiment, a sampling pump 18 may be disposed in the second exhaust pipe 125 for providing a certain flow pressure, which facilitates gas sampling under normal pressure conditions, and improves the efficiency controllability of sampling analysis. In this embodiment, sampling pump 18 has set up the terminal position at the gas circuit, and the gas circuit that sampling pump 18 itself probably brought connects and the material adsorbs scheduling problem, for setting up in the front end of gas circuit, its influence greatly reduced to detecting the precision, therefore this embodiment is preferred to be rearmounted sampling pump 18, is about to sampling pump 18 sets up in second blast pipe 125, can reduce the interference that sampling pump 18 itself brought, is favorable to detecting the improvement of precision.

The specific structure of the separation unit of the field portable gas detection device of the present invention is further described with reference to fig. 3-4, wherein fig. 3 shows the first and third state diagrams of the gas separation unit of the field portable gas detection device according to another embodiment of the present invention; fig. 4 shows a schematic view of a second state of the gas separation unit of fig. 3.

It is shown that the separation unit of the field portable gas detection apparatus of the present invention includes a ten-way valve 20 disposed inside the separation chamber 120, the ten-way valve 20 having first to tenth connection ports numbered in accordance with the order of the adjoining positions. Since there are too many connectors of the illustrated ten-way valve 20, the drawing is very confused by labeling specific reference numerals one by one, and for a clearer understanding, in fig. 3 and 4 of the present invention, each connector is numbered with arabic numerals in sequence according to adjacent positions, and each arabic numeral corresponds to a connector of chinese serial number of the same value, for example, the connector corresponding to arabic numeral 1 is shown in the following description as the first connector, the connector corresponding to arabic numeral 2 is shown in the following description as the second connector, and so on.

The ten-way valve 20 of the separation unit 12 of the field portable gas detection device of the present invention is shown, and the first connection port and the eighth connection port are communicated through a pipeline provided with a first chromatographic column 201; the second connection port communicates with a third exhaust pipe 126, and the third exhaust pipe 126 is provided with a second chromatography column 202 located between the second connection port and the detection unit 13; the third connection port communicates with the second intake pipe 122; the fourth connecting port is communicated with the seventh connecting port through a pipeline provided with a quantitative pipe 203; the fifth connection port is communicated with the second exhaust pipe 125; the sixth connection port is communicated with the third air inlet pipe 123; the ninth connection port communicates with the first exhaust pipe 124; the tenth connection port communicates with the first intake pipe 121.

The operation method of the field portable gas detection device of the present invention will be described in detail with reference to fig. 1 to 4, and the function and function of the connection structure of the separation unit 12 of the present invention can be more clearly understood through the process of operating gas analysis.

As shown in fig. 1-4, the operation method of the field portable gas detection device of the present invention comprises the following steps:

referring first to fig. 1 and 3, the ten-way valve 20 is adjusted by the control unit 15 to a first state, that is, the ten-way valve 20 has a first state in which the first connection port is communicated with the tenth connection port, the second connection port is communicated with the third connection port, the fourth connection port is communicated with the fifth connection port, the sixth connection port is communicated with the seventh connection port, and the eighth connection port is communicated with the ninth connection port.

Then, the sampling pump 18 is started, the sample gas is collected by the gas sampling unit 11, the sample gas is continuously introduced into the third gas inlet pipe 123, then enters the sixth connecting port and enters the quantitative tube 203 from the seventh connecting port, and the gas flowing out of the quantitative tube 203 enters the fourth connecting port and the fifth connecting port and then is exhausted through the second gas outlet pipe 125. By the continuous flow of the sample gas, a desired predetermined amount of the sample gas is stored in the quantitative tube 203, facilitating the next analytical detection.

Meanwhile, the control unit 15 makes the first path of carrier gas provided by the carrier gas unit 16 continuously pass through the first gas inlet pipe 121 and enter the tenth connection port and the first connection port, then flow through the first chromatographic column 201, and the gas flowing out of the first chromatographic column 201 enters the eighth connection port and the ninth connection port, and then is exhausted through the first exhaust pipe 124.

Meanwhile, the control unit 15 makes the second path of carrier gas provided by the carrier gas unit 16 pass through the second gas inlet pipe 122, enter the third connection port and the second connection port, flow through the second chromatographic column 202 through the third gas outlet pipe 126, and then the gas flowing out of the second chromatographic column 202 enters the detection unit 13 and is exhausted.

The first chromatographic column 201 and the corresponding connectors and pipelines are cleaned in sequence by using the first path of carrier gas, and the second path of carrier gas is used for emptying the second chromatographic column 202 and the detection unit 13 after being cleaned in sequence, so that the system can be cleaned by using the same gas source, the gas source is stable, the efficiency is higher, and more accurate detection results can be obtained subsequently. And after the cleaning is stable, the system reaches a preset state which can be analyzed and detected in the next step.

Then, when the system reaches a predetermined stable state, the control unit 15 may adjust the ten-way valve 20 from the first state shown in fig. 3 to the second state shown in fig. 4, that is, the ten-way valve 20 has a second state in which the first connection port communicates with the second connection port, the third connection port communicates with the fourth connection port, the fifth connection port communicates with the sixth connection port, the seventh connection port communicates with the eighth connection port, and the ninth connection port communicates with the tenth connection port in the second state shown in fig. 4.

At this time, the sampled sample gas is continuously introduced into the third gas inlet pipe 123 through the sampling pump 18 and the gas sampling unit 11, and then enters the sixth connection port and the fifth connection port and is evacuated from the second gas exhaust pipe 125. This process is arranged in keeping the gaseous flow of sample in the pipeline, and the air current interruption can not appear in the sampling of the next circulation of being convenient for to this continuity of guaranteeing continuous on-line analysis avoids appearing data jump and influences the detection precision, guarantees simultaneously that the malleation gas that lasts flows and can avoid the outside air to get into the gas circuit and cause the pollution, guarantees that the gas circuit is stable clean, thereby has further guaranteed the accuracy nature of analysis result.

Meanwhile, the control unit 15 makes the first path of carrier gas provided by the carrier gas unit 16 continuously pass through the first gas inlet pipe 121 to the tenth connection port and the ninth connection port, and then is exhausted through the first exhaust pipe 124. Therefore, the pipeline is continuously cleaned by the carrier gas, pollution is avoided, and next gas analysis is prepared.

Meanwhile, the control unit 15 makes the second path of carrier gas provided by the carrier gas unit 16 pass through the second gas inlet tube 122 and enter the third connector and the fourth connector, then the carrier gas enters the quantitative tube 203 by back flushing to push the sample gas stored in the quantitative tube 203 in the first state out of the quantitative tube 203, then the sample gas flows into the seventh connector and the eighth connector, and similarly the sample gas enters the first chromatographic column 201 by back flushing, under the action of the first chromatographic column 201, different gas components are analyzed and discharged at different speeds, the analyzed gas firstly passes through the first connector and the second connector, then flows into the second chromatographic column 202 through the third gas outlet tube 126, and enters the detection unit 13 for detection after being separated by the second chromatographic column 202.

The second state shown in fig. 4 appears superficially similar to the separation detection with the first 201 and second 202 chromatography columns connected in series, then the operation steps of the present invention are not simple series separation, but need to be switched to the following third state immediately after the first column 201 has been in a predetermined time for the analytical separation of the sample gas.

That is, according to the characteristics of the first chromatographic column 201, the time when the gas analyzed first is completely evacuated through the first chromatographic column 201 and enters the third exhaust pipe 126 can be calculated or obtained experimentally, and when the evacuation time of the gas analyzed first is reached, the control unit 15 automatically starts the state transition, that is, the control unit 15 adjusts the ten-way valve 20 from the second state to the third state, that is, the ten-way valve 20 has a third state in which the connection relationship of the ten-way valve 20 is the same as that in the first state, as shown in fig. 3, the same is true, at this time, the first connection port is communicated with the tenth connection port, the second connection port is communicated with the third connection port, the fourth connection port is communicated with the fifth connection port, the sixth connection port is communicated with the seventh connection port, and the eighth connection port is communicated with the ninth connection port.

At this time, the gas resolved first enters the third exhaust pipe 126 completely, and a part of the gas resolved first may reach the second chromatographic column 202 and even the detection unit 13 (this may be flexibly set by the volume of the third exhaust pipe 126 between the second connection port and the second chromatographic column 202, and depends on the width range of the target species zone). After that, the control unit 15 immediately switches from the second state to the third state, and the gas desorbed from the rear section of the first chromatographic column 201 is suddenly cut off and does not enter the third exhaust pipe 126 again. That is, in this step of the present invention, the gas component analyzed from the first chromatographic column 201 in the sample gas first needs to be the gas to be measured, and the gas component analyzed from the first chromatographic column 201 later is the useless impurity gas, so that the impurity peak generated after the gas enters the detecting unit 13 is prevented from reducing the curve accuracy of the gas to be measured.

After the state is switched to the third state, as shown in fig. 3, the collected sample gas is continuously introduced into the third gas inlet pipe 123 through the sampling pump 18 and the gas sampling unit 11, then enters the sixth connection port and enters the quantitative tube 203 from the seventh connection port, and the gas flowing out of the quantitative tube 203 enters the fourth connection port and the fifth connection port and is then evacuated through the second gas outlet pipe 125; thereby discharging the gas in the second state entirely for storing the sample gas for the next analysis in the quantitative tube 203.

Meanwhile, the control unit 15 makes the first path of carrier gas provided by the carrier gas unit 16 continuously enter the tenth connection port and the first connection port through the first gas inlet pipe 121, and then enters the first chromatographic column 201 through back flushing. The first column 201 originally retains the rear stage analysis gas which has not yet flowed out, and the waste gas is trapped when the second state is switched to the third state because of its slow passing speed. At this time, through the back-blowing action of the first path of carrier gas, the part of gas originally remaining in the first chromatographic column 201 can be easily pushed out of the first chromatographic column 201 by the first path of carrier gas through the back-blowing manner. With the continuous entering of the first path of carrier gas, all the original gas in the first chromatographic column 201 can be pushed out reversely, and then enters the eighth connecting port and the ninth connecting port, and is exhausted through the first exhaust pipe 124. That is, in this step, by switching to the third state, the exhaust gas in the first chromatographic column 201 can be blown clean in the reverse direction by the first path of carrier gas, because the speed of the exhaust gas passing through the first chromatographic column 201 is originally very slow, if the forward purging efficiency is very low, and through the reverse purging, the first chromatographic column 201 and the related pipeline interfaces and the like can be cleaned faster, the cleaning efficiency is higher, the required time is shorter, the purging and cleaning effect is much better than the forward purging effect, the problem that the species difficult to purge out in the forward purging have too long analysis time to enter the detection unit 13 of the next analysis is also avoided, thereby reducing the impurity interference, and improving the accuracy of the analysis result.

At the same time, the second path of carrier gas provided by the carrier gas unit 16 is continuously introduced into the third connection port and the second connection port through the second gas inlet pipe 121 by the control unit 15, and then flows into the third gas outlet pipe 126. The remaining gas to be detected, which is just the just intercepted gas to be detected and analyzed in the previous stage, in the third exhaust pipe 126 at this time is switched to the third state, and then the remaining gas to be detected is pushed to the second chromatographic column 202 by just passing through the second path of carrier gas to flow into the third exhaust pipe 126 in a relay manner, then the components in the gas to be detected are continuously analyzed and discharged at different speeds by the second chromatographic column 202 normally, and then the gas flowing out of the second chromatographic column 202 enters the detection unit 13 for detection and then is discharged; thus completing a cycle of gas analysis in the third state; the analysis result obtained by the detection unit 13 is further transmitted to the data acquisition and processing unit 14 through a circuit.

In this step, since the impurity gas with a longer resolving time is intercepted by the first chromatographic column 201 before and does not enter the third exhaust pipe 126, the gas component which is really required to be analyzed and detected is pushed to the second chromatographic column 202 through the second path of carrier gas, the gas to be detected with different components is resolved and discharged at different speeds by the second chromatographic column 202, the intervals of the curve wave crests of different gas components are opened, the mutual masking interference of adjacent wave crests is avoided, the detection degree of different components, especially trace components, is improved, and the detection precision is improved.

The utility model discloses in, the sample gas does not directly carry out the series analysis through first chromatographic column 201 and second chromatographic column 202 and detects, but first chromatographic column 201 has carried out one before the detection and has held back the operation, utilizes first chromatographic column 201 to carry out a preseparation to the sample gas, will resolve earlier the gaseous direction second chromatographic column that awaits measuring that goes out, cuts back end waste gas through the state switching and stays in first chromatographic column 201, later go out waste gas blowback and prepare next detection. The control unit 15 can set an appropriate time for the state transition according to the characteristics of the first chromatographic column 201, and can intercept the rear-stage exhaust gas other than the gas to be detected to be analyzed, and analyze only the front-stage gas to be detected.

To sum up, the utility model discloses a portable gaseous detection device in field provides whole built-in integrated overall structure in the box, and each structure is stable connection as an organic whole in the box, compact structure, and portable and transportation are applicable to the emergent gaseous analysis detection of various field environment. And the gas separation unit with an independent structure can conveniently form a highly integrated gas analyzer which can be conveniently exchanged, and the number of connecting pipelines and the number of control valves are reduced, so that the system error can be effectively reduced, and the reliability and the detection precision of the system are improved. Additionally, the utility model discloses a gaseous back flushing of holding back of gaseous miscellaneous peak that will resolve after through first chromatographic column of gas separation unit is favorable to waiting to examine the improvement of gaseous detection precision, later pulls open the crest interval of each composition through the second chromatographic column, has improved the detection degree of different compositions especially trace composition, has improved the detection precision.

It is to be understood by those skilled in the art that while the present invention has been described in terms of several embodiments, it is not intended that each embodiment cover a separate embodiment. The description is given for clearness of understanding only, and it is to be understood that all matters in the embodiments are to be interpreted as including all technical equivalents which are encompassed by the claims.

The above description is only exemplary of the present invention, and is not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations that may be made by those skilled in the art without departing from the spirit and principles of the invention should be considered within the scope of the invention.

Claims (7)

1. A field portable gas detection device comprises a box body (100), and is characterized in that the box body (100) is provided with a gas sampling unit (11), and a gas separation unit (12), a detection unit (13), a data acquisition and processing unit (14), a control unit (15) and a carrier gas unit (16) are arranged in the box body (100); wherein the gas separation unit (12) is arranged in an independent separation box (120), and the separation box (120) is provided with three air inlet pipes (121, 122, 123) and three air outlet pipes (124, 125, 126) communicated with the interior of the separation box; the three gas inlet pipes (121, 122, 123) are respectively a first gas inlet pipe (121) and a second gas inlet pipe (122) which are communicated with the carrier gas unit (16), and a third gas inlet pipe (123) which is communicated with the gas sampling unit (11); the three exhaust pipes (124, 125, 126) are respectively a first exhaust pipe (124) and a second exhaust pipe (125) for emptying, and a third exhaust pipe (126) communicated with the detection unit (13).

2. A field portable gas-detecting apparatus according to claim 1, characterized in that the data acquisition and processing unit (14) is connected to the detecting unit (13) by means of an electric circuit.

3. The field portable gas sensing device of claim 2, wherein said carrier gas unit (16) comprises a carrier gas cylinder (161), said carrier gas cylinder (161) providing a first and a second path of carrier gas through said first and second gas inlet tubes (121, 122), respectively.

4. A field portable gas detection apparatus according to claim 3, wherein said gas separation unit (12) comprises a ten-way valve (20) disposed inside said separation tank (120), said ten-way valve (20) having first to tenth connection ports numbered in sequence in adjacent positions; the first connecting port is communicated with the eighth connecting port through a pipeline provided with a first chromatographic column (201); the second connecting port is communicated with the third exhaust pipe (126), and the third exhaust pipe (126) is provided with a second chromatographic column (202) positioned between the second connecting port and the detection unit (13); the third connecting port is communicated with the second air inlet pipe (122); the fourth connecting port is communicated with the seventh connecting port through a pipeline provided with a quantitative pipe (203); the fifth connecting port is communicated with the second exhaust pipe (125); the sixth connecting port is communicated with the third air inlet pipe (123); the ninth connection port is communicated with the first exhaust pipe (124); the tenth connection port communicates with the first intake pipe (121).

5. The field portable gas sensing device of claim 4, wherein the ten-way valve (20) has a first state in which the first port communicates with the tenth port, the second port communicates with the third port, the fourth port communicates with the fifth port, the sixth port communicates with the seventh port, and the eighth port communicates with the ninth port.

6. The field portable gas sensing device as defined in claim 5, wherein the ten-way valve (20) has a second state in which the first port communicates with the second port, the third port communicates with the fourth port, the fifth port communicates with the sixth port, the seventh port communicates with the eighth port, and the ninth port communicates with the tenth port.

7. The field portable gas detection apparatus as defined in claim 6, wherein the ten-way valve (20) has a third state in which the ten-way valve (20) is connected in the same relationship as the first state.