Online continuous monitoring system and method for aldehyde and ketone compounds in gas

Abstract

The present invention provides an online continuous monitoring system and method for aldehyde and ketone compounds in gas, the online continuous monitoring system includes a detection unit; further includes: a bearing member is arranged on a base and rotates under the driving of a driving module; M groups of working units, M is an integer not less than 1, each group of working units includes P working units, P is an integer not less than 3; the working unit is arranged on the bearing member; during the rotation of the bearing member, each working unit is sequentially in a preparation work position, a sampling work position and a detection work position; the preparation flow path is arranged in the preparation work position, the sampling flow path is arranged in the sampling work position, and the detection flow path is arranged in the detection work position; the control device is used to control whether the working unit in the preparation work position enters the preparation flow path, whether the working unit in the sampling work position enters the sampling flow path, and whether the working unit in the detection work position enters the detection flow path. The present invention has the advantages of high work efficiency and accurate analysis results.

Description

Technical Field

[0001] The invention relates to gas monitoring, and in particular to an online continuous monitoring system and method for aldehyde and ketone compounds in gas. Background Art

[0002] At present, the sampling and analysis methods and related standards for aldehyde and ketone compounds are mainly based on offline sampling methods. For example, the national standard HJ683-2014 stipulates that after offline sampling using DNPH-silica gel adsorption tubes, the samples are transferred to the laboratory for analysis and detection using high-performance liquid chromatography. This offline working method has many shortcomings, such as:

[0003] 1. Affected by human factors, the preservation and transportation of samples require high standards;

[0004] 2. The high cost of consumables and manual analysis is not conducive to long-term high-frequency observation and cannot meet the current requirements for fine control of photochemical pollution;

[0005] 3. During the manual sampling process, the DNPH-silica gel adsorption tube is greatly affected by the ambient temperature, and the adsorption and derivatization efficiency of aldehydes and ketones on the adsorption tube is unstable, resulting in large measurement and analysis errors;

[0006] 4. This analysis method uses a packed column sampling tube coated with DNPH. The preparation process refers to the EPA TO-11A standard. The production process is complex, the storage conditions are strict, and the blank background value is required to be very high. Summary of the invention

[0007] In order to solve the deficiencies in the above-mentioned prior art solutions, the present invention provides an online continuous monitoring system for aldehyde and ketone compounds in gas which is automated, highly efficient and has accurate measurement.

[0008] The objective of the present invention is achieved through the following technical solutions:

[0009] An online continuous monitoring system for aldehyde and ketone compounds in gas, the online continuous monitoring system for aldehyde and ketone compounds in gas comprising a detection unit; and further comprising:

[0010] A base, a bearing and a driving module, wherein the bearing is arranged on the base and rotates under the driving of the driving module;

[0011] M groups of working units, M is an integer not less than 1, each group of working units includes P working units, P is an integer not less than 3; the working units are arranged on the carrier, the working units include silicone columns, and both ends of the silicone columns are open; during the rotation of the carrier, when one working unit in any group of working units is in the preparation working position, the other working units are respectively in the sampling working position and the detection working position, so that each working unit is in the preparation working position, the sampling working position and the detection working position in sequence;

[0012] A preparation flow path, a sampling flow path and a detection flow path, wherein the preparation flow path is arranged at the preparation work position, a silica gel column entering the preparation flow path forms a sampling column for adsorbing aldehyde and ketone compounds, the sampling flow path is arranged at the sampling work position, the detection flow path is arranged at the detection work position, and the detection unit is located in the detection flow path;

[0013] A control device is used to control whether a working unit at a preparation work position enters a preparation flow path, whether a working unit at a sampling work position enters a sampling flow path, and whether a working unit at a detection work position enters a detection flow path.

[0014] Another object of the present invention is to provide an online continuous monitoring method for aldehyde and ketone compounds in gas using the above-mentioned online continuous monitoring system for aldehyde and ketone compounds in gas. This object of the invention is achieved by the following technical solutions:

[0015] The online continuous monitoring method of aldehyde and ketone compounds in gas using the online continuous monitoring system of aldehyde and ketone compounds in gas of the present invention is as follows:

[0016] The carrier rotates, and when one working unit in any group of working units is in the preparation working position, the other working units are respectively in the sampling working position and the detection working position;

[0017] Under the control of the control device, the working unit at the preparation work position enters the preparation flow path, the silica gel column forms a sampling column for adsorbing aldehyde and ketone compounds, the sampling column at the sampling work position that has completed preparation enters the sampling flow path to adsorb aldehyde and ketone compounds in the environment to be tested, and the sampling column at the detection work position that has completed sampling enters the detection flow path;

[0018] Under the control of the control device, the working unit that has completed preparation at the preparation working position is separated from the preparation flow path, the sampling column that has completed sampling at the sampling working position is separated from the sampling flow path, and the sampling column that has completed detection at the detection working position is separated from the detection flow path;

[0019] The carrier further rotates so that each working unit is in the preparation working position, the sampling working position and the detection working position in sequence, and circulates.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. High work efficiency;

[0022] Through the design of work units and work cells, one work unit in the same group of work units is in the preparation work position to prepare the sampling column online, while another work unit with the prepared sampling column is in the sampling work position to realize online sampling, and the work unit after sampling is in the detection work position to realize online detection, that is, the preparation, sampling and detection of the sampling column corresponding to the same group of work units are carried out simultaneously, that is, parallel processing, which greatly reduces the waiting time of each link and significantly improves the work efficiency;

[0023] The simultaneous operation of the M group of working units (divided into single-turn one-time working cycle and multiple working cycles) further improves the work efficiency;

[0024] 2. Automation;

[0025] The working unit (including the silica gel column) automatically cycles between the preparation workstation, the sampling workstation and the detection workstation, and automatically enters and leaves the flow path corresponding to the workstation without manual intervention;

[0026] 3. Work continuously online;

[0027] Preparation, sampling and testing are carried out online, which significantly improves work efficiency;

[0028] There are working units that continuously enter the sampling working position and the detection working position cyclically, realizing continuous sampling and continuous detection (except for the time of switching between the two working units, which is short and can be ignored);

[0029] 4. Accurate test results;

[0030] The sampling column is regenerated at the preparation workstation, avoiding the need for long-distance transportation. The formaldehyde derivative is less than 10 ng / root, which has a lower background blank than the DNPH adsorption column specified in the existing national standard (formaldehyde derivative is less than 150 ng / root), and the measurement results at low concentrations are more reliable.

[0031] 5. Low testing cost;

[0032] The sampling column regeneration and reuse can realize automatic regeneration of consumables, reducing the cost of single sample consumables by more than 90%. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The disclosure of the present invention will become easier to understand with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. In the drawings:

[0034] Figure 1 2 is a schematic diagram of the structure of an online continuous monitoring system for aldehyde and ketone compounds in gas according to an embodiment of the present invention;

[0035] Figure 2 2 is a schematic diagram of the flow path structure of an online continuous monitoring system for aldehyde and ketone compounds in gas according to an embodiment of the present invention;

[0036] Figure 3 2 is a schematic diagram of the structure of an online continuous monitoring system for aldehyde and ketone compounds in gas according to an embodiment of the present invention;

[0037] Figure 4 Schematic diagram of the structure of an online continuous monitoring system for aldehyde and ketone compounds in gas according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] Figure 1-4 The following description describes the optional embodiments of the present invention to teach those skilled in the art how to implement and reproduce the present invention. In order to explain the technical solution of the present invention, some conventional aspects have been simplified or omitted. Those skilled in the art will understand that variations or replacements derived from these embodiments will be within the scope of the present invention. Those skilled in the art will understand that the following features can be combined in various ways to form multiple variations of the present invention. Thus, the present invention is not limited to the following optional embodiments, but is only limited by the claims and their equivalents.

[0039] Embodiment 1:

[0040] Figure 1 A schematic diagram of the structure of an online continuous monitoring system for aldehyde and ketone compounds in gas according to an embodiment of the present invention is given. Figure 1 As shown, the online continuous monitoring system for aldehyde and ketone compounds in the gas comprises:

[0041] A detection unit, such as a liquid chromatography detection unit;

[0042] A base, a carrier 41 and a driving module, wherein the carrier 41 is arranged on the base and rotates under the driving of the driving module;

[0043] M groups of working units, M is an integer not less than 1, each group of working units includes P working units, P is an integer not less than 3, such as a first working unit 21, a second working unit 22 and a third working unit 23; the working units are arranged on the carrier 41, and the working units include a silica gel column, and both ends of the silica gel column are open; in the forward or reverse rotation of the carrier 41, when one working unit in any group of working units is in the preparation working position, the other working units are respectively in the sampling working position and the detection working position, so that each working unit is in the preparation working position, the sampling working position and the detection working position in sequence;

[0044] A preparation flow path 11, a sampling flow path 31 and a detection flow path 51, wherein the preparation flow path 11 is arranged at the preparation work position, a silica gel column entering the preparation flow path 11 forms a sampling column for adsorbing aldehyde and ketone compounds, the sampling flow path 31 is arranged at the sampling work position, the detection flow path 51 is arranged at the detection work position, and the detection unit is located in the detection flow path 51;

[0045] A control device is used to control whether a working unit at a preparation work position enters a preparation flow path, whether a working unit at a sampling work position enters a sampling flow path, and whether a working unit at a detection work position enters a detection flow path.

[0046] In order for the working units at each working position to automatically enter the flow path, further, the control device includes:

[0047] a first moving member and a plurality of first pipelines, wherein the first pipelines are arranged on the first moving member and are located on the upper side of the bearing member, and the preparation flow path, the sampling flow path and the detection flow path are respectively connected to the first pipelines;

[0048] a second moving member and a plurality of second pipes, wherein the second pipes are arranged on the second moving member and are located at the lower side of the bearing member;

[0049] A guide rail and a driving unit, wherein the first moving member and the second moving member are respectively arranged on the guide rail, and the driving unit is used to drive the first moving member and the second moving member to move on the guide rail, so that the lower end of the first pipe is connected to and separated from the upper end opening of the working unit, and the upper end of the second pipe is connected to and separated from the lower end opening of the working unit.

[0050] In order to prepare (regenerate) the sampling column automatically online, further, as Figure 2As shown, the preparation flow path includes a first container, a first pump 45, a first column 81 and a second column 82, and a second container 73 connected in sequence; the second column 82 is connected to the first pipeline, and the second container 73 is connected to the second pipeline; DNPH powder is filled in the first column 81, and organic silica gel is filled in the second column 82;

[0051] A cleaning unit is used to remove the solvent entering the working unit of the preparation flow path.

[0052] In order to automatically clean and prepare (regenerate), the preparation flow path 11 further includes:

[0053] A first switching module 61, the first switching module 61 is used to make the outlet of the first pump 45 selectively connect to the first column 81 and the second pipeline;

[0054] The second switching module 62 is used to make the second column 82 selectively connect to the first column 81 and the second container 73 .

[0055] In order to quickly remove the solvent in the silica gel column, further, the removal unit includes:

[0056] A gas source 75, wherein the gas source 75 provides a purge gas;

[0057] The third switching module 63 is used to enable the working unit entering the preparation flow path 11 to selectively connect to the gas source 75 and the second column 82 .

[0058] In order to realize automatic preparation of the sampling column, further, the first container includes a first cleaning liquid container 71 and a coating liquid container 72;

[0059] The fourth switching module 64 is used to selectively connect the inlet of the first pump 45 to the first cleaning liquid container 71 and the coating liquid container 72 .

[0060] In order to automatically sample, the sampling flow path further comprises:

[0061] A pre-treatment unit, one end of which is connected to the air and the other end of which is connected to the second pipe;

[0062] A second pump 46 is connected to the first pipeline.

[0063] In order to automatically detect, further, the detection flow path includes:

[0064] A second cleaning liquid container 74 and a third pump 47, wherein the second cleaning liquid container 74, the third pump 47 and the first pipeline are connected in sequence;

[0065] The sample container 76 is connected to the second pipeline, and the detection unit 10 is connected to the sample container 76 .

[0066] The online continuous monitoring method of aldehyde and ketone compounds in gas according to the embodiment of the present invention, that is, the working method of the online continuous monitoring system of aldehyde and ketone compounds in gas according to the embodiment of the present invention, the online continuous monitoring method of aldehyde and ketone compounds in gas is:

[0067] The carrier 41 rotates, and when one working unit in any group of working units is in the preparation working position, the other working units are respectively in the sampling working position and the detection working position;

[0068] Under the control of the control device, the working unit at the preparation work position enters the preparation flow path 11, the silica gel column forms a sampling column for adsorbing aldehyde and ketone compounds, the sampling column at the sampling work position that has completed preparation enters the sampling flow path 31 to adsorb aldehyde and ketone compounds in the environment to be tested, and the sampling column at the detection work position that has completed sampling enters the detection flow path 51;

[0069] Under the control of the control device, the working unit that has completed preparation at the preparation working position is separated from the preparation flow path 11, the sampling column that has completed sampling at the sampling working position is separated from the sampling flow path 31, and the sampling column that has completed detection at the detection working position is separated from the detection flow path 51;

[0070] The carrier 41 further rotates, so that each working unit is in the preparation working position, the sampling working position and the detection working position in turn, and circulates, thereby completing the preparation, sampling and detection online and automatically.

[0071] In order to realize online and automatic preparation of the sampling column, further, in the preparation flow path 11, the silica gel column forms the sampling column in the following manner:

[0072] The cleaning liquid passes through the silica gel column and the second column 82 in sequence, and the second column 82 is filled with organic silica gel;

[0073] The coating liquid passes through the first column 81, the second column 82 and the silica gel column in sequence, and the first column 81 is filled with DNPH powder;

[0074] The solvent in the silica gel column is removed, and the silica gel column forms a sampling column.

[0075] Embodiment 2:

[0076] An example of application of the online continuous monitoring system and method for aldehyde and ketone compounds in gas according to Example 1 of the present invention in air monitoring.

[0077] In this application example, Figure 1As shown, the carrier 41 is a disk, and through holes are evenly arranged on the circumference of the disk; a group of working units is arranged on the carrier 41, and the only group of working units includes three working units, and the three working units (the first working unit 21, the second working unit 22 and the third working unit 23) are respectively arranged in the through holes, and the central angles corresponding to adjacent working units are 120 degrees; the working unit includes a silicone column (filled with pure silicone) with openings at the upper and lower ends; the driving module uses a motor to drive the carrier 41 to rotate;

[0078] In the control device, the first movable member and the second movable member are respectively disc-shaped and arranged on the vertical guide rail. The driving unit adopts a screw driven by a motor to independently drive the first movable member and the second movable member to move up and down on the vertical guide rail (only move up and down); three first pipes are evenly arranged on the circumference of the first movable member, when the first movable member moves vertically downward, the lower end of each first pipe is respectively connected and sealed with the upper end opening of the working unit on the carrier 41, when the first movable member moves vertically upward, the lower end of each first pipe is respectively separated from the upper end opening of the working unit on the carrier 41; three second pipes are evenly arranged on the circumference of the second movable member, when the first movable member moves vertically upward, the upper end of each second pipe is respectively connected and sealed with the lower end opening of the working unit on the carrier 41, when the second movable member moves vertically downward, the upper end of each second pipe is respectively separated from the lower end opening of the working unit on the carrier 41, thereby automatically controlling whether the working unit enters the flow path;

[0079] like Figure 2 As shown, the preparation flow path 11 is in the preparation working position, including the first container, the fourth switching module 64, the first pump 45, the first switching module 61, the first column 81, the second switching module 62, the second column 82 and the third switching module 63 connected in sequence, and the fifth switching module 65 and the second container 63 connected in sequence, the cleaning unit adopts the gas source 75; the third switching module 63 is connected to the first pipeline, the fifth switching module 65 is connected to the second pipeline, the first container includes a first cleaning liquid container 71 and a coating liquid container 72, the cleaning liquid adopts acetone, the coating liquid adopts isopropanol (or methanol, ethyl acetate) and an acid solution, and hydrochloric acid, boric acid, etc. can be used; the above switching modules all adopt electromagnetic three-way valves, one outlet of the first switching module 61 is connected to the second pipeline, one outlet of the second switching module 62 is connected to the second container 73, and the inlet of the third switching module 63 is connected to the first MFC91 and the gas source 75, such as a nitrogen bottle, in sequence; the first column 81 is filled with DNPH powder, and the second column 82 is filled with organic silica gel, such as Phenyl silica gel;

[0080] The sampling flow path 31 is in the sampling working position, and includes a pretreatment unit, a second MFC 92 and a second pump 46. The pretreatment unit includes a filter 56 and a deozonation column 57. The deozonation column 57 is connected to the second pipeline. The second pump 46, the second MFC 92 and the first pipeline are connected in sequence.

[0081] The detection flow path 51 is in the detection working state, including the second cleaning liquid container 74, the third pump 47 and the sixth switching module 66, as well as the sample container 76 and the detection unit 10 connected in sequence; the third pump 74 adopts a syringe pump, the sixth switching module 66 is connected to the first pipeline, the sample container 76 is connected to the second pipeline, and the detection unit 10 adopts a liquid chromatography detection unit; the gas source 75 is connected to the sixth switching module 66 through the third MFC93; the second cleaning liquid container 74 is filled with acetone.

[0082] The online continuous monitoring method of aldehyde and ketone compounds in gas according to the embodiment of the present invention, that is, the working method of the online continuous monitoring system of aldehyde and ketone compounds in gas according to the embodiment of the present invention, the online continuous monitoring method of aldehyde and ketone compounds in gas is:

[0083] The driving module drives the carrier 41 to rotate forward, and the first working unit 21 is in the preparation working position, while the second working unit 22 is in the sampling working position, and the third working unit 23 is in the detection working position;

[0084] The driving unit drives the first moving member to move downward and the second moving member to move upward, and the upper end openings of each first pipeline and the working unit are connected and sealed, and the upper end of the second pipeline and the lower end opening of the working unit are connected and sealed, so that the first working unit 21 enters the preparation flow path 11, that is, the third switching module 63, the first pipeline, the first working unit (silicone column) 21, the second pipeline and the fifth switching module 65 are connected, and at the same time, the second working unit 22 enters the sampling flow path 31, that is, the second pump 46, the second MFC92, the first pipeline, the second working unit (prepared sampling column) 22, the second pipeline, the deozonation column 57 and the filter 56 are connected, and the third working unit 23 enters the detection flow path 51, that is, the sixth switching module 66, the first pipeline, the third working unit (sampling column after sampling) 23, the second pipeline and the sample container 76 are connected;

[0085] In the preparation flow path, the first-fifth switching modules are switched. First, the cleaning liquid flows through the fourth switching module 64, the first pump 45, the first switching module 61, the fifth switching module 65, the first working unit (silicone column) 21, the third switching module 63, the second column 82 and the second switching module 62 in sequence, and then enters the second container 73, thereby cleaning the first working unit (silicone column) 21 and the second column 82; then, the coating liquid flows through the fourth switching module 64, the first pump 45, the first switching module 61, the first column 81, the second switching module 62, the second column 82, the third switching module 63, the first working unit (silicone column) 21 and the fifth switching module 65 in sequence, and then enters the second container 73; then, the nitrogen provided by the gas source 75 flows through the third switching module 63, the first working unit (silicone column) 21 and the fifth switching module 65 in sequence, thereby realizing the automated online preparation of the sampling column;

[0086] In the sampling flow path 31, the second pump 46 works, and the air flows through the filter 56, the deozonation column 57, the second working unit (prepared sampling column) 22, the second MFC 92, and the second pump 46 in sequence, and the aldehyde and ketone compounds in the air are adsorbed in the sampling column;

[0087] In the detection flow path 51, through the switching of the sixth switching module 66, first, the cleaning liquid flows through the third pump 47, the sixth switching module 66, the third working unit (the sampling column that has been sampled) 23 and the sample container 76 in sequence, and the DNPH derivative adsorbed in the third working unit (the sampling column that has been sampled) 23 enters the sample container 76, and then, the unit provided by the gas source 75 flows through the third MFC 93, the sixth switching module 66, the third working unit (the sampling column that has been sampled) 23 and the sample container 76 in sequence, achieving purging and bubbling mixing in the sample container 76; then, the liquid in the sample container 76 enters the detection unit 10 for detection; the above-mentioned preparation, sampling and detection are carried out simultaneously;

[0088] The driving unit drives the first moving member to move upward and the second moving member to move downward, so that the upper end openings of the first pipes and the working units are separated, and the upper ends of the second pipes and the lower end openings of the working units are separated;

[0089] The driving module drives the carrier 41 to rotate 120 degrees in the forward direction, and the third working unit 23 that has completed the detection is in the preparation working position. At the same time, the second working unit 22 that has completed the sampling is in the detection working position, and the first working unit 21 that has completed the preparation is in the sampling working position.

[0090] Under the control device, the third working unit 23 enters the preparation flow path 11, and at the same time, the second working unit 22 enters the detection flow path 51, and the first working unit 21 enters the sampling flow path 31. The way of entering each flow path is the same as above; the third working unit 23 automatically completes the sampling column preparation (regeneration) online, and at the same time, the second working unit 22 automatically detects online, and the first working unit 21 automatically samples online; the preparation, sampling and detection methods are the same as above;

[0091] Under the control device, the third working unit 23 is separated from the preparation flow path 11, and at the same time, the second working unit 22 is separated from the detection flow path 51, and the first working unit 21 is separated from the sampling flow path 31. The way of separating from each flow path is the same as above.

[0092] The driving module drives the carrier 41 to rotate 120 degrees in the forward direction, and the third working unit 23 that has completed preparation is in the sampling working position. Meanwhile, the second working unit 22 that has completed detection is in the preparation working position, and the first working unit 21 that has completed sampling is in the detection working position.

[0093] Under the control device, the third working unit 23 enters the sampling flow path 31, and at the same time, the second working unit 22 enters the preparation flow path 11, and the first working unit 21 enters the detection flow path 51. The way of entering each flow path is the same as above; the second working unit 22 automatically completes the sampling column preparation (regeneration) online, and at the same time, the third working unit 23 automatically samples online, and the first working unit 21 automatically detects online;

[0094] Under the control device, the third working unit 23 is separated from the sampling flow path 31, and at the same time, the second working unit 22 is separated from the preparation flow path 11, and the first working unit 21 is separated from the detection flow path 51;

[0095] The above cycle is repeated; it can be seen that, through the rotation of the carrier 41, each working unit is in the preparation work position, the sampling work position and the detection work position in turn, and cycles, thereby completing the preparation, sampling and detection online and automatically.

[0096] Embodiment 3:

[0097] The application example of the online continuous monitoring system and method of aldehyde and ketone compounds in gas according to Example 1 of the present invention in air monitoring is different from Example 2 in that:

[0098] like Figure 3As shown, there are two groups of working units, each group of working units includes three working units, the first group of working units includes a first working unit 21, a second working unit 22 and a third working unit 23, the second group of working units includes a fourth working unit 27, a fifth working unit 28 and a sixth working unit 29, the six working units of the two groups of working units are evenly arranged on the entire circumference of the carrier 41, and the central angle corresponding to two adjacent working units is 60 degrees; corresponding to the two groups of working units, the first preparation flow path 11 and the second preparation flow path 12 are respectively in the preparation working position, the first sampling flow path 31 and the second sampling flow path 32 are respectively in the sampling working position, and the first detection flow path 51 and the second detection flow path 52 are respectively in the detection working position;

[0099] Corresponding to the number of working units, the first moving member has six first pipes, and the second moving member has six second pipes. When the first moving member and the second moving member move up and down, the first pipes (second pipes) and the corresponding working units are connected and separated;

[0100] When the carrier 41 rotates one circle, each working unit undergoes two working cycles, such as being in the preparation work position, sampling work position, detection work position, preparation work position, sampling work position, and detection work position in sequence; at the same time, there are two working units (such as the first working unit 21 and the fourth working unit 27) preparing online, two working units (such as the second working unit 22 and the fifth working unit 28) sampling online, and two working units (such as the third working unit 23 and the sixth working unit 29) detecting online; every time the carrier 41 rotates 60 degrees, the working unit changes its work position.

[0101] Embodiment 4:

[0102] The application example of the online continuous monitoring system and method of aldehyde and ketone compounds in gas according to Example 1 of the present invention in air monitoring is different from Example 3 in that:

[0103] like Figure 4As shown, there are two groups of working units, each group of working units includes three working units, the first group of working units includes the first working unit 21, the second working unit 22 and the third working unit 23, and the second group of working units includes the fourth working unit 27, the fifth working unit 28 and the sixth working unit 29; the three working units of each group of working units are evenly arranged on the entire circumference of the carrier 41, and the central angle corresponding to two adjacent working units in each group is 120 degrees, that is, any working unit in the second group of working units is between adjacent working units of the first group of working units, and the central angle between adjacent working units of the first group of working units and working units of the second group of working units is less than 120 degrees, such as 30 degrees, 45 degrees, 60 degrees, 90 degrees; that is, the six working units are evenly or unevenly arranged on the entire circumference of the carrier 41; the number and position of the pipelines on the first moving member and the second moving member match the position of the working units on the carrier;

[0104] Every time the carrier 41 rotates 120 degrees, the working units in each group of working units change working positions, but the working units between groups will not change positions, for example, the working units in the first group of working units will not change positions to the corresponding working positions of the second group of working units.

[0105] It can be seen that every time the carrier 41 rotates one circle, the same working unit undergoes a working cycle, that is, it is in the preparation work position, sampling work position and detection work position at different times; at the same time, two working units are preparing online, two working units are sampling online, and two working units are detecting online.

[0106] The above embodiments provide the case of one or two groups of working units. Of course, there may be more groups, such as three, four or more groups. In this case, more preparation flow paths, sampling flow paths and detection flow paths need to be configured, as well as more pipelines for the first movable part and the second movable part.

Claims

1. An online continuous monitoring system for aldehyde and ketone compounds in gas, the online continuous monitoring system for aldehyde and ketone compounds in gas comprising a detection unit; characterized in that: The online continuous monitoring system for aldehyde and ketone compounds in the gas also includes: A base, a bearing and a driving module, wherein the bearing is arranged on the base and rotates under the driving of the driving module; M groups of working units, M is an integer not less than 1, each group of working units includes P working units, P is an integer not less than 3; the working units are arranged on the carrier, the working units include silicone columns, and both ends of the silicone columns are open; during the rotation of the carrier, when one working unit in any group of working units is in the preparation working position, the other working units are respectively in the sampling working position and the detection working position, so that each working unit is in the preparation working position, the sampling working position and the detection working position in sequence; A preparation flow path, a sampling flow path and a detection flow path, wherein the preparation flow path is arranged at the preparation work position, a silica gel column entering the preparation flow path forms a sampling column for adsorbing aldehyde and ketone compounds, the sampling flow path is arranged at the sampling work position, the detection flow path is arranged at the detection work position, and the detection unit is located in the detection flow path; A control device, the control device is used to control whether the working unit in the preparation work position enters the preparation flow path, whether the working unit in the sampling work position enters the sampling flow path, and whether the working unit in the detection work position enters the detection flow path; The preparation flow path includes a first container, a first pump, a first column, a second column, a silica gel column and a second container connected in sequence; DNPH powder is filled in the first column, and organic silica gel is filled in the second column; the first container includes a cleaning liquid container and a coating liquid container; A cleaning unit, the cleaning unit is used to remove the solvent entering the working unit of the preparation flow path; a first switching module, the first switching module being used to selectively connect the outlet of the first pump to the first column and a fifth switching module; a second switching module, the second switching module being used to selectively connect the second column with the first column and the second container; The fourth switching module is used to selectively connect the inlet of the first pump to the cleaning liquid container and the coating liquid container; A fifth switching module is used to enable the silica gel column to selectively connect the second container and the first switching module.

2. The online continuous monitoring system for aldehyde and ketone compounds in gas according to claim 1, characterized in that: The control device comprises: a first moving member and a plurality of first pipelines, wherein the first pipelines are arranged on the first moving member and are located on the upper side of the bearing member, and the preparation flow path, the sampling flow path and the detection flow path are respectively connected to the first pipelines; a second moving member and a plurality of second pipes, wherein the second pipes are arranged on the second moving member and are located at the lower side of the bearing member; A guide rail and a driving unit, wherein the first moving member and the second moving member are respectively arranged on the guide rail, and the driving unit is used to drive the first moving member and the second moving member to move on the guide rail, so that the lower end of the first pipe is connected to and separated from the upper end opening of the working unit, and the upper end of the second pipe is connected to and separated from the lower end opening of the working unit.

3. The online continuous monitoring system for aldehyde and ketone compounds in gas according to claim 1, characterized in that: The cleaning unit comprises: a gas source, the gas source providing a purge gas; A third switching module is used to enable the working unit entering the preparation flow path to selectively connect the gas source and the second column.

4. The online continuous monitoring system for aldehyde and ketone compounds in gas according to claim 2, characterized in that: The sampling flow path comprises: A pre-treatment unit, one end of which is connected to the air and the other end of which is connected to the second pipe; A second pump is connected to the first pipeline.

5. The online continuous monitoring system for aldehyde and ketone compounds in gas according to claim 2, characterized in that: The detection flow path comprises: a cleaning liquid container and a third pump, wherein the cleaning liquid container, the third pump and the first pipeline are connected in sequence; A sample container is connected to the second pipeline, and the detection unit is connected to the sample container.

6. An online continuous monitoring method for aldehyde and ketone compounds in gas using the online continuous monitoring system for aldehyde and ketone compounds in gas according to any one of claims 1 to 5, wherein the online continuous monitoring method for aldehyde and ketone compounds in gas is: The carrier rotates, and when one working unit in any group of working units is in the preparation working position, the other working units are respectively in the sampling working position and the detection working position; Under the control of the control device, the working unit at the preparation work position enters the preparation flow path, the silica gel column forms a sampling column for adsorbing aldehyde and ketone compounds, the sampling column at the sampling work position that has completed preparation enters the sampling flow path to adsorb aldehyde and ketone compounds in the environment to be tested, and the sampling column at the detection work position that has completed sampling enters the detection flow path; Under the control of the control device, the working unit that has completed preparation at the preparation working position is separated from the preparation flow path, the sampling column that has completed sampling at the sampling working position is separated from the sampling flow path, and the sampling column that has completed detection at the detection working position is separated from the detection flow path; The carrier further rotates so that each working unit is in the preparation working position, the sampling working position and the detection working position in sequence, and cycles; In the preparation flow path, the silica gel column forms the sampling column in the following way: The cleaning liquid passes through the silica gel column and the second column in sequence, and the second column is filled with organic silica gel; The coating liquid passes through the first column, the second column and the silica gel column in sequence, and the first column is filled with DNPH powder; The solvent in the silica gel column is removed, and the silica gel column forms a sampling column.

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