Calibrating device for dust concentration measuring instrument

Abstract

The utility model discloses a calibrating device for a dust concentration measuring instrument. The calibrating device comprises a dust supply device, a test fan drift, a dust remover, a plurality of sampling pieces and a detected instrument, the two ends of the test fan drift are connected with the dust supply device and the dust remover respectively, the multiple sampling pieces are connected into the test fan drift and located on the same vertical section of the test fan drift, sampling openings are formed in the top ends of the sampling pieces, and the bottoms of the sampling pieces extend out of the test fan drift and then are connected with a detected instrument. The device has the beneficial effects that the limitation of the internal space of the test fan drift is broken through, after the detected instruments are moved out, the number of the sampling pieces can be correspondingly expanded, a plurality of sampling pieces are added, a plurality of detected instruments can work simultaneously, a plurality of sampling ports work independently at the same time, airflow interference does not exist among the sampling ports, and the working efficiency is improved.

Description

Technical Field

[0001] This utility model relates to a calibration device, and more particularly to a device for periodically calibrating dust concentration measuring equipment. Background Technology

[0002] Dust concentration measuring equipment is increasingly being installed in underground coal mines to achieve real-time online monitoring of dust concentration. Periodic calibration of the CTF-Ⅳ dust concentration measuring instrument using a calibration device ensures the accuracy and reliability of the online monitoring data. This provides data support for comprehensive dust control and plays a crucial role in establishing a dust hazard early warning mechanism, thereby further guaranteeing safe production in coal mines.

[0003] like Figure 1 As shown, the working principle of the CTF-Ⅳ dust concentration measuring instrument calibration device is as follows: Based on the measurement range requirements of the dust concentration measuring equipment, this device generates a quantitative dust concentration value within the test duct and operates under certain wind speed conditions, creating a stable and uniform dust concentration test condition within the working section. A standard sampling device and the dust concentration measuring equipment under test are used to simultaneously sample and measure the dust concentration. The measured value is compared with the value displayed by the dust concentration measuring equipment under test to determine the sampling accuracy of the dust measuring equipment under test. The calibration device mainly consists of four parts: a test duct, a dust supply device, a standard sampling device, and an operating platform. The test duct is a straight-path type with a working section diameter of 800mm and a total length of 10m (including the fan and dust collector). The dust supply device is a disc-type jet dust supply, consisting of a dust collector, a dust supply disc, a stepper motor, a drive power supply, and an air compressor. The standard sampling device consists of a standard sampling tube, a filter membrane clamp, a flow meter, a flow stabilizer, and a flow regulating valve.

[0004] The existing CTF-Ⅳ dust concentration measuring instrument calibration device has the following drawbacks:

[0005] 1. The limited space within the ventilation shaft restricts the number of dust concentration measuring devices (hereinafter referred to as the tested instruments) that can be placed inside (maximum of two at a time). According to the requirements of the "Verification Procedure for Dust Concentration Measuring Instruments" (JJG846-2015), and considering the actual working conditions, it takes one day to complete the verification of two tested instruments (excluding subsequent data processing). This time-consuming and inefficient process results in high verification costs.

[0006] 2. According to the requirements of the "Verification Procedure for Dust Concentration Meters" (JJG846-2015), three measurement points at approximately 20%, 50%, and 80% of the measurement range of the instrument under test need to be selected for indication error verification. The process is as follows: After selecting the measurement points, the instrument under test needs to record a stable concentration display value every 10 seconds within one minute after dust generation stabilizes, for a total of 6 records. Each measurement point is then repeated 3 times according to the above steps. Statistics show that each measuring device needs to record up to 18 data points in a short period, and all data recording is done manually by two verification personnel, which is prone to errors, requires frequent rework, and significantly reduces work efficiency.

[0007] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0008] The technical problem to be solved by this utility model is: how to solve the problems of limited space, limited number of instruments to be tested, and long testing time in the existing dust concentration measuring instrument calibration device.

[0009] This utility model solves the above-mentioned technical problems through the following technical means:

[0010] The dust concentration measuring instrument calibration device includes a dust supply device, a test ventilation shaft, a dust collector, multiple sampling components, and the instrument under test. The two ends of the test ventilation shaft are connected to the dust supply device and the dust collector, respectively. Multiple sampling components are connected inside the test ventilation shaft and are located on the same vertical section of the test ventilation shaft. The top of the sampling component is the sampling port, and the bottom of the sampling component extends to the outside of the test ventilation shaft and is connected to the instrument under test.

[0011] Preferably, it also includes a hose, with the bottom of the sampling piece extending to the outside of the test duct and connected to one end of the hose, and the other end of the hose connected to the instrument under test.

[0012] Flexible hoses are used to connect the sampling ports inside the ventilation shaft to the instruments under test one by one to ensure equivalent transmission of the samples.

[0013] Preferably, the number of sampling components is odd, with the middle sampling component located at the center of the cross-section of the test wind tunnel, and the remaining sampling components distributed equidistantly on both sides of the middle sampling component.

[0014] Preferably, there are five sampling components. The inner diameter of the test ventilation shaft is 800mm. The middle sampling component is located at the center of the cross-section of the test ventilation shaft, and the other four sampling components are installed horizontally at 100mm intervals from the center to both ends.

[0015] Preferably, a connecting plate is connected to the bottom of the sampling component, and a mounting frame is connected inside the test air chamber. The connecting plates of multiple sampling components are all connected to the mounting frame.

[0016] Preferably, the sampling port of the sampling component is located in the working section of the test ventilation shaft.

[0017] Preferably, the number of sampling items is the same as the number of instruments being tested.

[0018] Preferably, the instrument under test is located below the test ventilation shaft.

[0019] The advantages of this utility model are:

[0020] This invention cleverly utilizes the negative pressure suction sampling characteristic of the instrument under test. By moving the bottom of its sampling port outside the test chamber and connecting it to the instrument under test, the instrument under test can be successfully moved from inside the test chamber to outside. This successfully overcomes the limitations of the internal space of the test chamber. After the instrument under test is removed, the number of sampling components can be expanded accordingly, allowing multiple sampling components to be added. This enables multiple instruments under test to work simultaneously, and multiple sampling ports to work independently without airflow interference between them, thus improving work efficiency.

[0021] Flexible hoses are used to connect the sampling ports inside the ventilation shaft to the instruments under test one by one to ensure equivalent transmission of the samples.

[0022] Meanwhile, moving the instrument under test outside the test tunnel not only makes the observed data clearer and more intuitive, but more importantly, it reduces the impact of the number of times the tunnel's observation window is opened and closed on the data. During the operation, the error caused by human factors is eliminated, ensuring the traceability of the data.

[0023] The improved power supply system no longer passes through the test ventilation shaft, providing independent power and eliminating electrostatic interference. This improves calibration safety and eliminates the problem of electrostatic interference causing reading inconsistencies in the tested instruments, thus enhancing the reliability of calibration results. Reducing the frequency of opening and closing the test ventilation shaft's observation window also lowers the level of environmental pollution in the testing room to some extent. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the existing CTF-Ⅳ dust concentration measuring instrument calibration device of this utility model;

[0025] Figure 2 This is a schematic diagram of the dust concentration measuring device of this utility model being sampled in a calibration device;

[0026] Figure 3 This is a distribution diagram of the sampling components in an embodiment of this utility model;

[0027] Figure 4 This is a schematic diagram of the structure of the sampling component according to an embodiment of this utility model;

[0028] Numbering on the map:

[0029] 1. Dust supply device; 2. Test air chamber; 21. Mounting frame; 3. Dust collector; 4. Sampling component; 41. Connecting plate; 5. Hoses; 6. Instrument under test. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0031] Example 1:

[0032] like Figure 2 As shown, the dust concentration detection equipment includes a dust supply device 1, a test ventilation shaft 2, a dust collector 3, multiple sampling components 4, a flexible hose 5, and an instrument under test 6. The two ends of the test ventilation shaft 2 are connected to the dust supply device 1 and the dust collector 2, respectively. The bottoms of the multiple sampling components 4 are connected inside the test ventilation shaft 2, and the multiple sampling components 4 are located in the same vertical plane of the test ventilation shaft 2. The top of the sampling component 4 is the sampling port, located in the working section of the test ventilation shaft 2. The bottom of the sampling component 4 extends to the outside of the test ventilation shaft 2 and connects to the flexible hose 5, which is connected to the instrument under test 6.

[0033] The dust supply device 1 is used to provide dust-laden airflow, and the dust collector 3 is used to collect dust.

[0034] In this embodiment, the sampling ports within the test ventilation shaft 2 are designed to be installed on the same cross-section and at the same height, with the center point of the test ventilation shaft 2 as the sampling range. For example... Figure 3 As shown, there are five sampling components 4. The middle sampling component 4 is located at the center of the cross-section of the test wind tunnel 2, and the other four sampling components 4 are distributed equidistantly on both sides of the middle sampling component 4.

[0035] like Figure 2 As shown, the inner diameter of the test ventilation shaft 2 is 800mm. Experiments have verified that the effective dust collection radius of the instrument under test is 20mm. There are 5 sampling components 4. One of them is installed at the center of the cross-section of the test ventilation shaft 2. The other four sampling components 4 are installed horizontally at 100mm intervals from the center to both ends. The total span of the 5 sampling components 4 is 400mm. This makes the effective collection radius between each sampling port independent of each other, while avoiding the influence of the weak airflow zone on the inner wall of the test ventilation shaft 2, thus ensuring the sampling effect of the sampling port.

[0036] This embodiment is not limited to the number of sampling pieces 4. The number can be adjusted according to the inner diameter of the test ventilation shaft 2. The distance between adjacent sampling pieces 4 can be set according to the effective radius of the collected dust. The number of instruments 6 under test can be matched with the number of sampling pieces 4.

[0037] The test air chamber 2 is supported by the dust supply device 1 and the dust collector 3 at both ends, and is suspended in the air below. The instrument under test 6 can be placed below the test air chamber 2, and multiple instruments under test 6 are placed on a mobile frame.

[0038] In this embodiment, a hole is opened at the bottom of the test ventilation shaft 2 for the sampling component 4 to pass through. After the sampling component 4 passes through the test ventilation shaft, it is connected to the hose 5. The hose 5 can be a rubber tube with the same inner diameter as the sampling component 4.

[0039] The working process of this embodiment is as follows: According to the requirements of the "Verification Procedure for Dust Concentration Meters" (JJG846-2015), a stable concentration display value of the tested instrument is recorded every 10 seconds. As the number of instruments increases, the amount of data generated also increases significantly. A signal converter is used to convert the digital signal generated by the tested instrument into a frequency signal, automatically recording the data in real time and uploading it to computer software. The software records the detection data, forming the original verification record and generating a verification report. The entire process is seamless and fully automated. This greatly reduces the impact of human factors on the verification data and improves data processing efficiency.

[0040] This embodiment cleverly utilizes the negative pressure suction sampling characteristic of the tested instrument 6. The bottom of its sampling component 4 is moved horizontally to the outside of the test ventilation shaft 2 and connected to the tested instrument 6. This successfully moves the tested instrument 6 from inside the test ventilation shaft 2 to the outside, overcoming the limitations of the internal space of the test ventilation shaft 2. The number of tested instruments 6 is correspondingly expanded according to the number of sampling components 4 inside the test ventilation shaft 2. The designed and installed five sampling ports work independently simultaneously without airflow interference. Rubber tubes of the same inner diameter and length are used to connect the sampling ports inside the ventilation shaft to the tested instruments one-to-one, ensuring equivalent sampling transmission and increasing work efficiency by five times.

[0041] Moving the tested instrument 6 outside the test ventilation shaft 2 not only made the observed data clearer and more intuitive, but more importantly, it reduced the impact of the number of times the ventilation shaft's observation window was opened and closed on the data. During the operation, the influence of human error was eliminated, ensuring the traceability of the data.

[0042] The improved power supply system no longer passes through the test ventilation shaft, providing independent power and eliminating electrostatic interference. This improves calibration safety and eliminates the problem of sensor reading distortion caused by electrostatic interference, thus enhancing the reliability of calibration results. Reducing the number of times the test ventilation shaft's observation window is opened and closed also lowers the level of environmental pollution in the testing room to some extent.

[0043] Example 2:

[0044] like Figure 3 As shown, based on the above embodiment one, the bottom of the sampling component 4 is connected to the connecting plate 41. Since the test ventilation shaft 2 is cylindrical, a mounting frame 21 can be installed inside the test ventilation shaft 2. The sampling component 4 is connected to the mounting frame 21 through the connecting plate 41. The mounting frame 21 is an inverted concave frame. The mounting frame 21 can be connected to the inner wall of the test ventilation shaft 2 by welding or bonding. Multiple connection holes can be opened on the connecting plate 41, and multiple connection holes can be opened on the mounting frame 21. The connecting plate 41 and the mounting frame 21 are connected by bolts.

[0045] The bottom of the sampling component 4 is connected to the first connecting tube, and the top of the instrument under test 6 is connected to the second connecting tube. The first and second connecting tubes are used for a sealed connection with the hose 5.

[0046] The project has been successfully implemented in a company, and its economic and social benefits are significant.

[0047] (1) After the transformation, the verification process was automated, the data processing efficiency was improved many times, and the accuracy and reliability of the data were ensured. It also filled the gap in the intelligentization of this verification device.

[0048] (2) Before the renovation, each instrument under inspection required two people to operate simultaneously, and it took three days to complete the calibration work. After the renovation, the time required to calibrate a dust concentration measuring instrument was reduced from 6 working days / person to 0.5 working days / person. The labor efficiency was increased by 12 times, greatly reducing the required labor force. It is estimated that the annual labor cost will be reduced by 300,000 yuan.

[0049] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A dust concentration measuring instrument calibration device, characterized in that, It includes a dust supply device, a test air chamber, a dust collector, multiple sampling components, and the instrument under test. The two ends of the test air chamber are connected to the dust supply device and the dust collector, respectively. Multiple sampling components are connected inside the test air chamber and are located on the same vertical section of the test air chamber. The top of the sampling component is the sampling port, and the bottom of the sampling component extends to the outside of the test air chamber and is connected to the instrument under test.

2. The dust concentration measuring instrument calibration device according to claim 1, characterized in that, It also includes a hose, with the bottom of the sampling piece extending to the outside of the test ventilation shaft and connected to one end of the hose, and the other end of the hose connected to the instrument under test.

3. The dust concentration measuring instrument calibration device according to claim 1, characterized in that, The number of sampling components is odd, with the central sampling component located at the center of the cross-section of the test wind tunnel, and the remaining sampling components distributed equidistantly on both sides of the central sampling component.

4. The dust concentration measuring instrument calibration device according to claim 3, characterized in that, The sampling components consist of five parts. The inner diameter of the test ventilation shaft is 800 mm. The middle sampling component is located at the center of the cross-section of the test ventilation shaft, and the other four sampling components are installed horizontally at 100 mm intervals from the center to both ends.

5. The dust concentration measuring instrument calibration device according to claim 1, characterized in that, A connecting plate is connected to the bottom of the sampling piece, and a mounting frame is connected inside the test air chamber. The connecting plates of multiple sampling pieces are all connected to the mounting frame.

6. The dust concentration measuring instrument calibration device according to claim 1, characterized in that, The sampling port of the sample is located in the working section of the test ventilation shaft.

7. The dust concentration measuring instrument calibration device according to claim 1, characterized in that, The number of sampling items is the same as the number of instruments being tested.

8. The dust concentration measuring instrument calibration device according to claim 1, characterized in that, The instrument under test is located below the test ventilation shaft.

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