Sampler with gas path switching and sampling method

Abstract

The present application relates to a kind of sampler with gas path switching, including controller, and respectively with the sampler pump and switching electromagnetic valve of the controller connection, one end of the switching electromagnetic valve is connected with the sampler pump by gas guide pipe, the other end of the switching electromagnetic valve is respectively equipped with first gas inlet pipe and second gas inlet pipe, first gas inlet and second gas inlet for gas inlet are respectively equipped on the first gas inlet pipe and the second gas inlet pipe, sampling medium is arranged at the first gas inlet, bypass back pressure control device is equipped on the second gas inlet pipe, and the bypass back pressure control device is connected with the controller;It also includes gas pressure sensor for measuring gas pressure, and the gas pressure sensor is connected with the controller.The present application also relates to a kind of sampling method based on the above sampler, by the sampler and sampling method, the influence caused by deviation to detection result in sampling process can be effectively reduced, so that sampling data is more accurate.

Description

Technical Field

[0001] This invention relates to the field of atmospheric sampling equipment technology, and in particular to a sampler and sampling method with gas path switching. Background Technology

[0002] Commonly used fully automatic air samplers typically employ air flow sensors and pressure sensors as detection devices. By detecting the sampling flow rate and sampling time, they obtain the final amplified and converted detection values, compare them with the set values ​​in the control unit, and then output instructions to the execution unit (sampling pump) for compensation and adjustment. Therefore, the stability and accuracy of the sampling flow rate and the accuracy of the sampling time are crucial during the sampling process.

[0003] like Figure 1 As shown, the sampling stability band is the part we need in the entire acquisition process. A complete sampling process may have multiple starts and stops. During startup, the sampling system needs to compensate and adjust to reach the set sampling flow rate and correspond to the back pressure of the sampling medium, thus generating a deviation band at the front end. At the end, the sampling system will carry the original sampling inertia, causing a deviation band at the back end. If this deviation band is included in the sampling data, it will affect the final result.

[0004] In actual sampling, many factors can cause deviations in the sampling flow rate. For example, there will be a certain flow rate deviation between the two time periods when the sampling device starts and stops, and there will be a deviation after restarting the sampling after a sampling error event stops. When these factors disturb the closed-loop system, the system will find a new balance point through its own compensation and adjustment. This compensation process is a deviation band that affects the sampling accuracy. In the case of short-term sample collection and multiple short-term intermittent samples being combined into a single sample, this flow rate deviation will cause a significant decrease in the overall sampling accuracy, resulting in a situation that far exceeds the accuracy requirements of the sampler industry. Summary of the Invention

[0005] Therefore, it is necessary to provide a sampler and sampling method with gas path switching to address the above problems. This can effectively reduce the impact of deviation bands on the detection results during the sampling process, making the sampling results more accurate.

[0006] The technical solution is as follows:

[0007] On one hand, a sampler with gas path switching is provided, including a controller, a sampling pump and a switching solenoid valve respectively connected to the controller. One end of the switching solenoid valve is connected to the sampling pump through a gas guide pipe, and the other end of the switching solenoid valve is respectively provided with a first air inlet pipe and a second air inlet pipe. The first air inlet pipe and the second air inlet pipe are respectively provided with a first air inlet and a second air inlet for air intake. A sampling medium is provided at the first air inlet, and a bypass back pressure control device is provided on the second air inlet pipe. The bypass back pressure control device is connected to the controller. It also includes a gas pressure sensor for measuring gas pressure, and the gas pressure sensor is connected to the controller.

[0008] The technical solution will be further explained below:

[0009] In one embodiment, the system further includes a housing, in which the controller, sampling pump, switching solenoid valve, first air inlet pipe, second air inlet pipe, air guide pipe and air outlet pipe are all disposed, and the first air inlet, second air inlet and air outlet are disposed outside the housing.

[0010] In one embodiment, a touch screen is provided on one side of the housing, and the touch screen is connected to the controller.

[0011] In one embodiment, the sampling pump is further provided with an exhaust pipe, the exhaust pipe is provided with an exhaust port, the air guide pipe is provided with a first pressure measuring port, the exhaust pipe is provided with a second pressure measuring port, and the first pressure measuring port and the second pressure measuring port are respectively provided with the gas pressure sensor.

[0012] In one embodiment, the outlet pipe is further provided with a buffer for buffering the airflow, the buffer being disposed between the sampling pump and the second pressure measuring port.

[0013] On the other hand, a sampling method based on the above-mentioned sampler with gas path switching is also provided, which further includes the following steps:

[0014] S1. Control the sampling pump to start via the controller;

[0015] S2. Install the sampling medium at the first air inlet, select the back pressure corresponding to the sampling medium, and set the back pressure of the bypass back pressure control device to be consistent with the back pressure of the sampling medium through the controller.

[0016] S3. Set the sampling flow rate and sampling time;

[0017] S4. Start the sampling pump start switch. At this time, the solenoid valve will connect the second air inlet pipe and the air guide pipe.

[0018] S5. When the real-time flow rate in the second air intake pipe deviates from the set value within the preset range, the switching solenoid valve disconnects the second air intake pipe and simultaneously connects the first air intake pipe to perform formal sampling of the sampling medium; otherwise, the air intake flow rate is adjusted by the sampling pump.

[0019] S6. When the gas flow rate of the sampling medium deviates from the sampling flow rate in step S2 within the preset range and the sampling time has been reached, the sampling ends.

[0020] The technical solution will be further explained below:

[0021] In one embodiment, the preset range value in steps S5 and S6 is ±5%.

[0022] In one embodiment, step S6 specifically includes the following steps:

[0023] S61. When the gas flow rate of the sampling medium deviates from the sampling flow rate in step S2 within the preset range, normal sampling shall continue until the sampling time is reached.

[0024] S62. During normal sampling, if the gas flow rate of the sampling medium deviates from the sampling flow rate in step S2 by a value exceeding the preset range and cannot be adjusted by the sampling pump, it is determined to be a fault, and the process jumps to step S4 to restart the sampling pump.

[0025] The beneficial effects of this invention are:

[0026] Compared with the prior art, the sampler and sampling method of the present invention with air path switching sets the sampling medium at the first air inlet of the first air inlet pipe to realize the sampling of the sampling medium. Specifically, the sampling power is provided by the sampling pump and controlled by the controller, which is simple and convenient to operate.

[0027] Furthermore, to avoid deviation bands during the start-up and shutdown of the sampling pump, a second air inlet pipe with a bypass back pressure control device is installed. During sampling, the controller sets the back pressure value of the bypass back pressure control device electronically based on the back pressure value of the corresponding sampling medium at the corresponding flow rate. After setting, the sampling system is started. Before reaching the set back pressure value and flow rate, the solenoid valve switches to operate on the second air inlet pipe. When the real-time flow rate is within the preset range, the solenoid valve switches to the first air inlet pipe to begin the formal sampling process. When the sampling time or sampling volume reaches the set value, the air path switches to the bypass control device end, and the sampling pump stops operating. Thus, during the sampling of the sampling medium, the deviation bands during the start-up and shutdown phases of the sampling pump are avoided, ensuring that the entire sampling process remains within the sampling stability range and guaranteeing the accuracy of the sampling data. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 Real-time flow graph of the sampling process described in the background art;

[0031] Figure 2 This is a schematic diagram of the shell structure in one embodiment;

[0032] Figure 3 This is a partial exploded schematic diagram of a sampler with gas path switching in one embodiment;

[0033] Figure 4 This is a schematic diagram of the gas path connection of a sampler with gas path switching in one embodiment;

[0034] Figure 5 This is a schematic diagram of a sampler with gas path switching in one embodiment;

[0035] Figure 6 This is a flowchart of a sampling method using a sampler with gas path switching in one embodiment.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Controller; 2. Sampling pump; 3. Switching solenoid valve; 4. First air inlet pipe; 5. Second air inlet pipe; 6. First air inlet; 7. Second air inlet; 8. Sampling medium; 9. Bypass back pressure control device; 10. Gas pressure sensor; 11. Housing; 12. Touch screen; 13. Air outlet pipe; 14. Air outlet; 15. First pressure measuring port; 16. Second pressure measuring port; 17. Buffer; 18. Air guide pipe. Detailed Implementation

[0038] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] In the description of this invention, it should be noted that the terms "inner," "outer," "upper," "lower," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," "fourth," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "fixation," and "tightly fitting," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or a connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] like Figures 2 to 5 As shown, in one embodiment, a sampler with gas path switching is provided, including a controller 1, a sampling pump 2 and a switching solenoid valve 3 respectively connected to the controller 1. One end of the switching solenoid valve 3 is connected to the sampling pump 2 through a gas guide pipe 18, and the other end of the switching solenoid valve 3 is respectively provided with a first air inlet pipe 4 and a second air inlet pipe 5. The first air inlet pipe 4 and the second air inlet pipe 5 are respectively provided with a first air inlet 6 and a second air inlet 7 for air intake. A sampling medium 8 is provided at the first air inlet 6. A bypass back pressure control device 9 is provided on the second air inlet pipe 5 and is connected to the controller 1. It also includes a gas pressure sensor 10 for measuring gas pressure and is connected to the controller 1.

[0042] In this embodiment, a sampling medium 8 is provided at the first air inlet 6 of the first air inlet pipe 4 to achieve sampling of the sampling medium 8. Specifically, the sampling power is provided by the sampling pump 2 and controlled by the controller 1, which is simple and convenient to operate.

[0043] Furthermore, to avoid deviation bands during the start-up and shutdown of sampling pump 2, a second air inlet pipe 5 with a bypass back pressure control device 9 is also provided. During sampling operations, controller 1 sets the back pressure value of the bypass back pressure control device 9 electronically based on the back pressure value of the corresponding sampling medium 8 at the corresponding flow rate. After setting, the sampling system is started. Before reaching the set back pressure value and flow rate, the solenoid valve 3 is switched to operate on the second air inlet pipe 5. When the real-time flow rate value and the set value are within the preset range, the solenoid valve 3 switches to the first air inlet pipe 4 to start the formal sampling process. When the sampling time or sampling volume reaches the set value, the air path switches to the bypass control device end, and the operation of sampling pump 2 is stopped. Thus, during the sampling operation of sampling medium 8, the deviation bands during the start-up and shutdown phases of sampling pump 2 are avoided, ensuring that the entire sampling process remains within the sampling stability band and guaranteeing the accuracy of the sampling data.

[0044] In one embodiment, the system further includes a housing 11. The controller 1, sampling pump 2, switching solenoid valve 3, first air inlet pipe 4, second air inlet pipe 5, air guide pipe 18, and air outlet pipe 13 are all housed within the housing 11. The first air inlet 6, second air inlet 7, and air outlet 14 are located outside the housing 11. Housed within the housing 11, all components and parts are protected, especially for outdoor operations, and the housing also facilitates carrying and transportation. Furthermore, the location of the first air inlet 6, second air inlet 7, and air outlet 14 outside the housing 11 facilitates air intake and exhaust operations, and in specific scenarios, can be used via external pipes.

[0045] In one embodiment, a touch screen 12 is provided on one side of the housing 11. The touch screen 12 is connected to the controller 1, allowing direct operation of the controller 1 via the touch screen 12. This facilitates the setting of various parameters and the control of the sampling pump 2. Simultaneously, the operator can also intuitively observe the real-time sampling status on the touch screen 12 to take appropriate actions.

[0046] In one embodiment, the sampling pump 2 is further provided with an exhaust pipe 13, an exhaust port 14 for venting gas, a first pressure measuring port 15 on the gas guide pipe 18, and a second pressure measuring port 16 on the exhaust pipe 13. Gas pressure sensors 10 are respectively installed at the first pressure measuring port 15 and the second pressure measuring port 16. By comparing the values ​​of the gas pressure sensors 10 at the first pressure measuring port 15 and the second pressure measuring port 16, the gas flow rate can be accurately determined, reducing errors in the system's judgment due to inaccurate gas flow rate values ​​and helping to ensure the accuracy of the sampling operation.

[0047] In one embodiment, the outlet pipe 13 is further provided with a buffer 17 for buffering the airflow. The buffer 17 is disposed between the sampling pump 2 and the second pressure measuring port 16. The airflow is buffered by the buffer 17 to avoid the airflow speed being too fast and easily causing deviation in the detection results.

[0048] like Figure 5 As shown, in one embodiment, a sampling method based on the above-described sampler with gas path switching is also provided, which further includes the following steps:

[0049] S1. Control the sampling pump 2 to start via controller 1;

[0050] S2. Install the sampling medium 8 at the first air inlet 6, select the back pressure corresponding to the sampling medium 8, and set the back pressure of the bypass back pressure control device 9 to be consistent with the back pressure of the sampling medium 8 through the controller 1.

[0051] S3. Set the sampling flow rate and sampling time;

[0052] S4. Start the sampling pump 2 start switch. At this time, switch the solenoid valve 3 to connect the second air inlet pipe 5 and the air guide pipe 18.

[0053] S5. When the real-time flow rate in the second air inlet pipe 5 deviates from the set value within the preset range, the switching solenoid valve 3 disconnects the second air inlet pipe 5 and simultaneously connects the first air inlet pipe 4 to perform formal sampling of the sampling medium 8; otherwise, the air inlet flow rate is adjusted by the sampling pump 2.

[0054] S6. When the gas flow rate of the sampling medium 8 deviates from the sampling flow rate in step S2 within the preset range and the sampling time has been reached, the sampling ends.

[0055] The technical solution will be further explained below:

[0056] In one embodiment, the preset range value in steps S5 and S6 is ±5% to ensure that the final sampling result is within the standard range. Of course, the preset range value can be adjusted according to the actual sampling situation and indicators, and is not limited to the above ±5%, as long as it is to ensure that the sampling result is within the range of the final sampling standard. Such designs are all within the protection scope of this invention.

[0057] In one embodiment, step S6 specifically includes the following steps:

[0058] S61. When the gas flow rate of the sampling medium 8 deviates from the sampling flow rate in step S2 within a preset range, normal sampling shall continue until the sampling time is reached.

[0059] S62. During normal sampling, if the gas flow rate of the sampling medium 8 deviates from the sampling flow rate in step S2 by a value exceeding the preset range and cannot be adjusted by the sampling pump 2, it is determined to be a fault, and the process jumps to step S4 to restart the sampling pump 2.

[0060] In practice, the cause of the malfunction may be that during prolonged sampling, dust, particles, and other impurities in the sampling medium 8 adhere to the first air inlet 6 or the first air inlet pipe 4, causing blockage. This prevents the sampling pump 2 from operating at maximum power, ensuring that the gas flow rate of the sampling medium 8 is within the preset range. In this case, the pump needs to be stopped, the fault identified, and then restarted for sampling. Of course, there are many other possible causes for the malfunction, such as blockages caused by foreign objects or human error. All of these require restarting to avoid inaccurate sampling results.

[0061] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A sampler with gas path switching, characterized in that, The system includes a controller (1), a sampling pump (2) and a switching solenoid valve (3) connected to the controller (1). One end of the switching solenoid valve (3) is connected to the sampling pump (2) through a gas guide pipe (18). The other end of the switching solenoid valve (3) is provided with a first air inlet pipe (4) and a second air inlet pipe (5). The first air inlet pipe (4) and the second air inlet pipe (5) are respectively provided with a first air inlet (6) and a second air inlet (7) for air intake. A sampling medium (8) is provided at the first air inlet (6). A bypass back pressure control device (9) is provided on the second air inlet pipe (5). The bypass back pressure control device (9) is connected to the controller (1). The system also includes a gas pressure sensor (10) for measuring gas pressure. The gas pressure sensor (10) is connected to the controller (1). When performing sampling operations, the controller (1) sets the back pressure value of the bypass back pressure control device (9) by electronic control according to the back pressure value of the corresponding sampling medium at the corresponding flow rate. After setting, the sampling system is started. Before the set back pressure value and flow rate are reached, the solenoid valve (3) is switched to connect the second air inlet pipe (5) and the air guide pipe (18). When the real-time flow rate value deviates from the set value within the preset range, the solenoid valve (3) is switched to the first air inlet pipe (4) to start the formal sampling process. When the sampling time or sampling volume reaches the set value, the air path is switched to one end of the bypass back pressure control device (9), and the sampling pump (2) stops working.

2. A sampler with gas path switching according to claim 1, characterized in that, The sampling pump (2) is also provided with an air outlet pipe (13), the air outlet pipe (13) is provided with an air outlet (14) for exhausting air, the air guide pipe (18) is provided with a first pressure measuring port (15), the air outlet pipe (13) is provided with a second pressure measuring port (16), and the first pressure measuring port (15) and the second pressure measuring port (16) are respectively provided with the gas pressure sensor (10).

3. A sampler with gas path switching according to claim 2, characterized in that, It also includes a housing (11), the controller (1), sampling pump (2), switching solenoid valve (3), and the first air inlet pipe (4), the second air inlet pipe (5), the air guide pipe (18) and the air outlet pipe (13) are all located inside the housing (11), and the first air inlet (6), the second air inlet (7) and the air outlet (14) are located outside the housing (11).

4. A sampler with gas path switching according to claim 3, characterized in that, A touch screen (12) is provided on one side of the housing (11), and the touch screen (12) is connected to the controller (1).

5. A sampler with gas path switching according to claim 4, characterized in that, The outlet pipe (13) is also provided with a buffer (17) for buffering the airflow. The buffer (17) is located between the sampling pump (2) and the second pressure measuring port (16).

6. A sampling method based on a sampler with gas path switching according to any one of claims 1 to 5, characterized in that, It also includes the following steps: S1. Control the sampling pump (2) to start via controller (1); S2. Install the sampling medium (8) at the first air inlet (6), select the back pressure corresponding to the sampling medium (8), and set the back pressure of the bypass back pressure control device (9) to be consistent with the back pressure of the sampling medium (8) through the controller (1); S3. Set the sampling flow rate and sampling time; S4. Start the sampling pump (2) and start the switch. At this time, switch the solenoid valve (3) to connect the second air inlet pipe (5) and the air guide pipe (18). S5. When the real-time flow rate in the second air inlet pipe (5) deviates from the set value within the preset range, switch the solenoid valve (3) to disconnect the second air inlet pipe (5) and simultaneously connect the first air inlet pipe (4) to perform formal sampling of the sampling medium (8); otherwise, adjust the air inlet flow rate through the sampling pump (2). S6. When the deviation between the gas flow rate of the sampling medium (8) and the sampling flow rate in step S3 is within the preset range and the sampling time has been reached, the sampling ends.

7. A sampling method according to claim 6, characterized in that, The preset range value in steps S5 and S6 is ±5%.

8. A sampling method according to claim 6, characterized in that, Step S6 specifically includes the following steps: S61. When the deviation between the gas flow rate of the sampling medium (8) and the sampling flow rate in step S3 is within the preset range, normal sampling shall be maintained until the sampling time is reached. S62. During normal sampling, if the gas flow rate of the sampling medium (8) deviates from the sampling flow rate in step S3 by a value exceeding the preset range and cannot be adjusted by the sampling pump (2), it is determined to be a fault and the process jumps to step S4 to restart the sampling pump (2).

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