Dust measuring device and dust explosion-proof control system

Abstract

The invention belongs to the technical field of industrial dust explosion safety prevention and control, and particularly relates to a dust measuring device and a dust explosion-proof control system. The first detection element is used for sensing an electrostatic signal of dust in the dusty gas at a first position; the second detection element is used for sensing an electrostatic signal of dust in the dusty gas at a second position; the third detection element is used for generating a resistance signal when being in contact with the dust-containing gas; the data processor is used for determining the flow rate of the dusty gas according to the time difference of the two electrostatic signals, determining the dust concentration according to the electrostatic signals and determining the temperature of the dusty gas according to the resistance signals. According to the invention, a plurality of different detection elements are arranged in the same section of monitoring pipe body, so that synchronous measurement of three measurement parameters of flow velocity, temperature and dust concentration of the same dusty gas can be realized, the data space-time consistency is good, the monitoring precision of the dust measurement device is improved, and correlation analysis, process control and safety explosion-proof control are facilitated.

Description

Technical Field

[0001] This application belongs to the field of industrial dust explosion safety prevention and control technology, and particularly relates to a dust measuring device and a dust explosion prevention control system. Background Technology

[0002] In numerous industrial sectors such as coal mining, grain processing, and metal processing, dust is a major risk source that endangers occupational health, causes safety accidents, and affects production efficiency. It can not only lead to occupational health problems such as pneumoconiosis, but also cause secondary dust pollution, and even destructive dust explosions when it reaches a certain concentration. Therefore, effective monitoring and timely control of dust are crucial for achieving safe production, protecting human health, and improving the environment.

[0003] Dust control typically involves key processes such as dust-laden pneumatic conveying, dust removal and purification, or combustion treatment. In these key processes, real-time, accurate, and continuous monitoring of the flow rate, temperature, and dust concentration of dust-laden gas in pipelines (such as flues) or enclosed spaces is directly related to process safety, equipment efficiency, emission compliance, and energy consumption control.

[0004] Currently, monitoring the flow rate, temperature, and dust concentration of dust-laden gas in pipelines typically employs a combination of discrete instruments: a Pitot tube, thermal, or ultrasonic flow meter is used to measure flow rate; an insertion thermocouple or resistance temperature detector (RTD) is used to measure temperature; and a separate dust concentration meter based on optical, electrostatic, or triboelectric principles is used to measure concentration. This discrete instrument combination not only requires multiple mounting holes in the pipeline, making installation complex and potentially damaging to the pipeline structure, but also easily leads to asynchronous data from multiple sensors in time and space, making accurate correlation difficult. Consequently, it cannot provide accurate data references for subsequent explosion-proof control. Furthermore, the measurement accuracy and reliability of discrete instruments are easily affected under low flow rate, high humidity, or complex flow field conditions. Summary of the Invention

[0005] This application aims to provide a dust measuring device and a dust explosion-proof control system, which greatly improves the measurement accuracy of the flow rate, temperature and dust concentration of dust-laden gas, and helps with subsequent explosion-proof control.

[0006] This application provides a dust measuring device, comprising: a monitoring tube for conveying dust-laden gas; a first detection element disposed on the inner wall of the monitoring tube for sensing an electrostatic signal of dust in the dust-laden gas at a first position; a second detection element disposed on the inner wall of the monitoring tube and spaced apart from the first detection element for sensing an electrostatic signal of dust in the dust-laden gas at a second position; a third detection element at least partially disposed within the monitoring tube for generating a resistance signal upon contact with the dust-laden gas; and a data processor connected to the first detection element, the second detection element, and the third detection element. The data processor is configured to determine the flow rate of the dust-laden gas based on the time difference between the electrostatic signals transmitted by the first and second detection elements, to determine the dust concentration in the dust-laden gas based on the electrostatic signals transmitted by the first and / or second detection elements, and to determine the temperature of the dust-laden gas based on the resistance signal transmitted by the third detection element.

[0007] In an optional embodiment of this application, the second detection element is located downstream of the first detection element along the flow direction of the dust-laden gas, and the third detection element is also located downstream of the second detection element along the flow direction of the dust-laden gas. The data processor is configured to determine the flow velocity of the dust-laden gas based on the time difference between the electrostatic signals transmitted by the first and second detection elements and the distance between them along the flow direction of the dust-laden gas, and is also configured to determine the dust concentration in the dust-laden gas based on the electrostatic signal transmitted by the second detection element.

[0008] In an optional embodiment of this application, the axial length of the first detection element along the flow direction of the dust-laden gas is: The axial distance between the inlet end of the first detection element and the inlet end of the second detection element is ,and Between 0.15 and 0.30.

[0009] In an optional embodiment of this application, the data processor includes a speed processing module, a concentration processing module, a temperature processing module, and a housing that houses the speed processing module, the concentration processing module, and the temperature processing module. The speed processing module is connected to the first detection element and the second detection element, and is configured to determine the flow velocity of the dust-laden gas based on the time difference between the electrostatic signals sent by the first and second detection elements and the distance between the first and second detection elements in the flow direction of the dust-laden gas. The concentration processing module is connected to the second detection element and is configured to determine the dust concentration in the dust-laden gas based on the electrostatic signal sent by the second detection element. The concentration processing module is connected to the third detection element and is configured to determine the temperature of the dust-laden gas based on the resistance signal sent by the third detection element.

[0010] In an optional embodiment of this application, the concentration processing module includes a first conversion circuit, a first amplification circuit, a peak detection circuit, and a second conversion circuit connected in sequence. The first conversion circuit is connected to the second detection element and converts the electrostatic signal sent by the second detection element into a first voltage signal. The first amplification circuit amplifies the first voltage signal. The peak detection circuit detects the amplified first voltage signal until it reaches a first target voltage and then transmits the first target voltage to the second conversion circuit, which converts the first target voltage into a first current signal. The first current signal corresponds one-to-one with the dust concentration, allowing the dust concentration in the dust-laden gas to be obtained based on the first current signal.

[0011] In an optional embodiment of this application, the concentration processing module further includes a second amplification circuit, which is disposed between the peak detection circuit and the second conversion circuit, and is used to amplify the first voltage signal sent by the peak detection circuit. The first amplification circuit is a two-stage amplification circuit, and the second amplification circuit is a single-stage amplification circuit.

[0012] In an optional embodiment of this application, the temperature processing module includes a power supply regulator circuit, a Wheatstone bridge circuit, a differential amplifier circuit, and a current drive circuit connected in sequence. The power supply regulator circuit is connected to the Wheatstone bridge circuit and supplies power to the Wheatstone bridge circuit, the differential amplifier circuit, and the current drive circuit. The Wheatstone bridge circuit is connected to the third detection element and converts the resistance signal sent by the third detection element into a second voltage signal. The differential amplifier circuit processes the second voltage signal to obtain a second target voltage, and the current drive circuit converts the second target voltage into a second current signal. The second current signal corresponds one-to-one with the temperature, so that the temperature of the corresponding dust-laden gas is obtained based on the second current signal.

[0013] In an optional embodiment of this application, both the first detection element and the second detection element include an induction coil, wherein the induction coil has a spiral ring electrode structure.

[0014] In an optional embodiment of this application, the first detection element, the second detection element, and the third detection element are connected to the data processor via signal lines. The monitoring tube has an opening communicating with its interior, and the dust measuring device further includes a connecting tube and a fixed base. The fixed base is located outside the monitoring tube and is fixedly connected to the monitoring tube at the opening. The fixed base has a channel communicating with the opening, and the connecting tube passes through the channel and the opening and is connected to the fixed base. The third detection element is located within the connecting tube and partially extends into the monitoring tube. The signal lines connecting the first, second, and third detection elements pass through the connecting tube to connect to the data processor.

[0015] In an optional embodiment of this application, the monitoring tube, the housing, the connecting tube, and the fixing base are metal components and are grounded.

[0016] A second aspect of this application provides a dust explosion-proof control system, which includes any of the dust measuring devices described above and a controller, wherein the controller performs explosion-proof control based on the flow rate, temperature and dust concentration of the dust-laden gas monitored by the dust measuring device.

[0017] In summary, the solution provided in this application has at least the following beneficial effects:

[0018] In the dust measuring device provided in this application, by integrating the first, second, and third detection elements into the same monitoring tube, near-synchronous measurement of three parameters—flow rate, temperature, and dust concentration—of the same dust-laden gas can be achieved. This results in good spatiotemporal consistency of the data, improving the monitoring accuracy of the dust-laden gas and facilitating subsequent correlation analysis, process control, and explosion-proof safety control. Furthermore, when measuring the flow rate of the dust-laden gas, the gas itself acts as a signal carrier, and the calculation is performed based on the time difference between the electrostatic signals sent by the upstream and downstream first and second detection elements. The entire measurement process involves no moving parts, avoiding wear on the first and second detection elements and improving the overall reliability of the dust measuring device. When measuring the dust concentration, the electrostatic signal of at least one of the first and second detection elements can be used to determine the dust concentration. Using both simultaneously improves the monitoring accuracy. When measuring the temperature of the dust-laden gas, contact measurement with the third detection element ensures accurate temperature monitoring. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the specific embodiments of this application, the drawings used in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the dust measuring device provided according to an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the concentration processing module of the data processor provided according to an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of the temperature processing module of the data processor provided according to an embodiment of this application.

[0023] The attached icons are numbered as follows:

[0024] 100. Dust measuring device;

[0025] 1. Monitoring tube body; 2. First detection element; 3. Second detection element; 4. Third detection element;

[0026] 5. Data processor; 51. Speed ​​processing module; 52. Concentration processing module; 521. First conversion circuit; 522. First amplification circuit; 523. Peak detection circuit; 524. Second conversion circuit; 525. Second amplification circuit; 53. Temperature processing module; 531. Power supply regulator circuit; 532. Wheatstone bridge circuit; 533. Differential amplifier circuit; 534. Current drive circuit; 54. Housing;

[0027] 6. Connecting pipe body; 7. Fixing base; 8. Sealing element;

[0028] The axial length of the first detection element;

[0029] The axial distance between the inlet end of the first detection element and the inlet end of the second detection element;

[0030] The distance between the first detection element and the second detection element in the direction of flow of the dust-laden gas. Detailed Implementation

[0031] To make the above and other features and advantages of this application clearer, the application is further described below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explanation to those skilled in the art and are exemplary only, not restrictive.

[0032] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "a plurality of" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects.

[0033] This application provides a dust measuring device that can be connected to the gas conveying pipeline of a dust removal system, the dust-laden gas conveying pipeline of a pneumatic conveying system, or the dust-laden gas conveying pipeline of a combustion treatment system. Of course, it is not limited to these connections; the dust measuring device can also be connected to the conveying pipeline of any other system that needs to monitor dust-laden gas.

[0034] Figure 1 This is a schematic diagram of the dust measuring device provided according to an embodiment of this application.

[0035] See Figure 1 The dust measuring device 100 may include a monitoring tube 1, a first detection element 2, a second detection element 3, a third detection element 4, and a data processor 5.

[0036] The interior of the monitoring tube 1 serves as a monitoring channel for dust-laden gas, used to transport the gas. At least one end of the monitoring tube 1 can be directly connected to the main transport pipeline for the dust-laden gas via a flange. The monitoring tube 1 can be a single-layer or multi-layer structure. The main transport pipeline for the dust-laden gas can be a dust removal pipeline or a combustion furnace or dust-laden gas transport pipeline (such as a flue) involved in a combustion process. In other words, the monitoring tube 1 can be connected to a dust removal pipeline, a combustion furnace, or a flue. A first detection element 2 is disposed on the inner wall of the monitoring tube 1 and is used to sense the electrostatic signal of dust particles in the dust-laden gas at a first position. It should be noted that when the dust-laden gas flows within its transport pipeline, it rubs against the inner wall of the pipeline, causing the dust particles in the gas to become charged. When the charged dust particles pass through the first detection element 2, the first detection element 2 can sense a weak, alternating electrostatic signal at its location (i.e., the first position).

[0037] The first detection element 2 can be disposed at any position on the monitoring tube 1. Preferably, the first detection element 2 can be disposed at the end of the monitoring tube 1. Further, the first detection element 2 can be disposed at the end of the monitoring tube 1 that receives the dust-laden gas.

[0038] The second detection element 3 is disposed on the inner wall of the monitoring tube 1 and spaced apart from the first detection element 2, and is used to sense the electrostatic signal of dust in the dust-laden gas at the second position. When a charged dust particle passes through the second detection element 3, the second detection element 3 can also sense another weak, alternating electrostatic signal at its location (i.e., the second position). In other words, different electrostatic signals can be detected at different locations on the inner wall of the monitoring tube 1 by using different detection elements.

[0039] The second detection element 3 can be arranged upstream or downstream of the first detection element 2 along the flow direction of the dust-laden gas. Furthermore, when the first detection element 2 is located at the end of the monitoring tube 1 that receives the dust-laden gas, the second detection element 3 can also be arranged close to that end and spaced a certain distance from the first detection element 2.

[0040] At least a portion of the third detection element 4 is disposed within the monitoring tube 1, and is used to generate a resistance signal when in contact with dust-laden gas. The third detection element 4 may be disposed between the first detection element 2 and the second detection element 3, or on the side of the first detection element 2 away from the second detection element 3, or on the side of the second detection element 3 away from the first detection element 2.

[0041] The data processor 5 is connected to the first detection element 2, the second detection element 3, and the third detection element 4. The data processor 5 is the core component of the dust measuring device 100. It can receive relevant data information sent by the first detection element 2, the second detection element 3, and the third detection element 4 in real time, process the received relevant data information through built-in calibration algorithms and compensation models, and convert the processed results into standard industrial signals or digital protocols for output.

[0042] The data processor 5 is configured to determine the flow rate of the dust-laden gas based on the time difference between the electrostatic signals sent by the first detection element 2 and the second detection element 3. That is, when measuring the flow rate of the dust-laden gas, the dust-laden gas itself is used as a signal carrier, and the calculation is performed based on the time difference between the electrostatic signals sent by the upstream and downstream first detection element 2 and the second detection element 3, which is a non-contact measurement.

[0043] The data processor 5 is configured to determine the dust concentration in the dust-laden gas based on the electrostatic signals sent by the first detection element 2 and / or the second detection element 3. That is, when measuring the dust concentration in the dust-laden gas, the dust concentration can be determined using only the electrostatic signal sent by the first detection element 2, only the electrostatic signal sent by the second detection element 3, or both the electrostatic signals sent by the first and second detection elements 2 and 3.

[0044] Furthermore, when determining the dust concentration in the dust-laden gas using the electrostatic signals sent by the first detection element 2 and the second detection element 3, a dust concentration can be determined first based on the electrostatic signal sent by the first detection element 2 and another dust concentration based on the electrostatic signal sent by the second detection element 3. Then, the two dust concentrations can be processed to obtain the final dust concentration, such as by taking the average or by performing a weighted average (the detection element with higher accuracy has a greater weight).

[0045] The data processor 5 is also configured to determine the temperature of the dust-laden gas based on the resistance signal sent by the third detection element 4. The third detection element 4 generates a resistance signal when it comes into contact with the dust-laden gas, which is a contact-type measurement.

[0046] In the dust measuring device 100 of this application, by integrating the first detection element 2, the second detection element 3, and the third detection element 4 into the same monitoring tube 1, near-synchronous measurement of three parameters—flow rate, temperature, and dust concentration—of the same dust-laden gas can be achieved. This results in good spatiotemporal consistency of the data, improving the monitoring accuracy of the dust measuring device 100 for dust-laden gas. It facilitates subsequent correlation analysis, process control, and safety and explosion-proof control, making it particularly suitable for industrial dust removal pipelines, pneumatic conveying systems, combustion flues, and other applications requiring dust safety and process control. Furthermore, when measuring the flow rate of the dust-laden gas, the dust-laden gas itself is used as a signal carrier. The flow rate is calculated based on the time difference between the electrostatic signals sent by the upstream and downstream first detection element 2 and second detection element 3. This is a non-contact measurement method, with no moving parts throughout the measurement process, avoiding wear on the first detection element 2 and second detection element 3 and improving the overall reliability of the dust measuring device 100. When measuring the dust concentration of dust-laden gas, the dust concentration can be determined using the electrostatic signal of at least one of the first detection element 2 and the second detection element 3. Using the electrostatic signals of both simultaneously improves the monitoring accuracy of the dust concentration. When measuring the temperature of dust-laden gas, using the third detection element 4 in contact with the dust-laden gas ensures accurate temperature monitoring.

[0047] In some embodiments, see Figure 1 Both the first detection element 2 and the second detection element 3 include an induction coil, which has a spiral ring electrode structure. The induction coil may be covered with an insulating layer, which may be made of polytetrafluoroethylene (PTFE).

[0048] Because the spiral ring electrode structure forms a larger "virtual sensing area" on the cross-section of the monitoring tube 1, dust particles in the dusty gas have a longer path and a longer time to be near the sensitive electric field generated by the electrode when passing through the pipe of the monitoring tube 1. This not only increases the probability that the induction coil will detect the electrostatic signal on the dust particles to improve the detection limit and signal stability at low concentrations, but also reduces the measurement deviation caused by uneven distribution of dust in the pipe (such as due to gravity deposition or turbulence).

[0049] In some embodiments, see Figure 1 The second detection element 3 is located downstream of the first detection element 2 along the flow direction of the dust-laden gas, and the third detection element 4 is located downstream of the second detection element 3 along the flow direction of the dust-laden gas. That is, the second detection element 3 is located between the first detection element 2 and the third detection element 4 along the flow direction of the dust-laden gas.

[0050] Here, since the second detection element 3 is closer to the middle region of the monitoring tube 1 than the first detection element 2, the airflow in the region where the second detection element 3 is located is more stable than the airflow in the region where the first detection element 2 is located. Therefore, setting the data processor 5 to determine the dust concentration in the dust-laden gas based on the electrostatic signal sent by the second detection element 3 can further improve the measurement accuracy of the dust concentration in the dust-laden gas. Furthermore, the data processor 5 is also set to determine the flow velocity of the dust-laden gas based on the time difference between the electrostatic signals sent by the first detection element 2 and the second detection element 3, and the distance between the first detection element 2 and the second detection element 3 in the flow direction of the dust-laden gas.

[0051] When charged dust particles pass through the first detection element 2, a weak electrostatic signal (signal 1) is generated in the first detection element 2 due to electrostatic induction. Then, as the airflow continues downstream, a similar electrostatic signal (signal 2) is generated in the second detection element 3. Simultaneously, the data processor 5 accurately captures the generation times of these two electrostatic signals and calculates their time difference. The distance between the first detection element 2 and the second detection element 3 in the direction of dust gas flow is combined. The flow velocity of the dust-laden gas is determined. That is, the flow velocity of the dust-laden gas can be determined using the formula... get.

[0052] In some embodiments, see Figure 1 Along the flow direction of the dust-laden gas, the axial length of the first detection element 2 is The axial distance between the inlet end of the first detection element 2 and the inlet end of the second detection element 3 is ,and Between 0.15 and 0.30. For example, It can be 0.15, 0.17, 0.19, 0.21, 0.23, 0.25, 0.27, 0.29, 0.30, etc.

[0053] Here, the axial length of the first detection element 2 is... The axial distance between the inlet end of the first detection element 2 and the inlet end of the second detection element 3 The ratio between them is set within the above range. On the one hand, this ensures that the first detection element 2 has sufficient length to generate a sufficiently large induced electrostatic signal, thereby ensuring that the induced electrostatic signal of the first detection element 2 can still be reliably detected under low concentration and low flow rate conditions. On the other hand, it avoids the ambiguity in judging the moment when the signal front corresponds to the dust entry due to the excessive axial length of the first detection element 2, thus preventing the introduction of time measurement errors.

[0054] This is because when the axial length of the first detection element 2 is too long, it will increase the pulse width of the induced electrostatic signal. Too large, and the electrostatic signal pulse width An excessively large pulse width can lead to ambiguity in determining the moment the dust enters the signal, introducing time measurement errors. Therefore, in this application, to accurately detect the signal leading edge, the electrostatic signal pulse width is... With the flow rate of dust-laden gas The following conditions must be met:

[0055] (1);

[0056] (2).

[0057] Based on formulas (1) and (2), we obtain .

[0058] When the axial length of the first detection element 2 is too short, the sensing area of ​​the first detection element 2 will be insufficient, resulting in a low amplitude of the induced electrostatic signal, which is easily affected by noise. This is especially problematic when the dust concentration is below 10 mg / m³ or when dust particles are unevenly distributed across the pipe cross-section, potentially preventing effective timing. Therefore, in this application, to improve the statistical stability of signal triggering and avoid false or missed triggers caused by single large particles or local concentration fluctuations, this application determines the signal-to-noise ratio (SNR) based on a signal-to-noise ratio (SNR) model. Less than or equal to 0.15, that is .

[0059] Specifically, the signal-to-noise ratio (SNR) model is as follows:

[0060] (3).

[0061] here, Where S is the dust concentration, and SNR is the signal-to-noise ratio. The signal-to-noise ratio SNR needs to be guaranteed to be greater than 10:1 at the minimum design concentration of 1 mg / m³.

[0062] Furthermore, the axial length of the first detection element 2 The axial distance between the inlet end of the first detection element 2 and the inlet end of the second detection element 3 The ratio between them is between 0.15 and 0.25. For example, The values ​​can be 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, etc.

[0063] The axial length of the first detection element 2 The axial distance between the inlet end of the first detection element 2 and the inlet end of the second detection element 3 Setting the ratio between them within the above range can minimize time measurement errors.

[0064] Furthermore, it should be noted that this application ensures a sufficient distance between the first detection element 2 and the second detection element 3. To improve Under the premise of measurement accuracy, control It also helps to reduce the space occupied by the dust measuring device 100 and avoid the total length of the monitoring tube 1 being limited by the installation space.

[0065] Based on the above design, the dust measuring device 100 can achieve, but is not limited to, measurements under conditions of flow velocity range of 0.5 to 30 m / s and concentration range of 1 to 1000 mg / m³.

[0066] In some embodiments, see Figure 1 The data processor 5 may include a speed processing module 51, a concentration processing module 52, a temperature processing module 53, and a housing 54. The housing 54 houses the speed processing module 51, the concentration processing module 52, and the temperature processing module 53.

[0067] The speed processing module 51 is connected to the first detection element 2 and the second detection element 3, and is configured to determine the flow rate of the dust-laden gas based on the time difference between the electrostatic signals sent by the first detection element 2 and the second detection element 3, and the distance between the first detection element 2 and the second detection element 3 in the flow direction of the dust-laden gas.

[0068] The concentration processing module 52 is connected to the second detection element 3 and is configured to determine the dust concentration in the dust-laden gas based on the electrostatic signal sent by the second detection element 3. Specifically, based on the principle of electrostatic induction, when charged dust particles pass by, the second detection element 3 will sense signal 2, which is an extremely weak pulse current signal. After being received by the concentration processing module 52, this pulse current signal can be processed into a stable DC voltage signal that is proportional to the dust concentration. That is, the dust concentration corresponding to this DC voltage signal is the dust concentration of the dust-laden gas.

[0069] The temperature processing module 53 is connected to the third detection element 4 and is configured to determine the temperature of the dust-laden gas based on the resistance signal sent by the third detection element 4.

[0070] Specifically, the third detection element 4 can be a temperature sensing element, which can be a platinum resistance thermometer (such as a PT100 platinum resistance thermometer). The temperature processing module 53 can determine the temperature of the dust-laden gas based on the temperature and resistance relationship of the third detection element 4. That is, when the third detection element 4 comes into contact with the dust-laden gas, the temperature of the third detection element 4 itself changes due to the temperature of the dust-laden gas. At the same time, the resistance of the third detection element 4 itself will change. The temperature processing module 53 can collect the current resistance signal of the third detection element 4 in real time to deduce the temperature of the dust-laden gas.

[0071] Figure 2 This is a schematic diagram of the concentration processing module of the data processor provided according to an embodiment of this application.

[0072] See Figure 2 The concentration processing module 52 may include a first conversion circuit 521, a first amplification circuit 522, a peak detection circuit 523, and a second conversion circuit 524 connected in sequence.

[0073] The first conversion circuit 521 is connected to the second detection element 3 and is used to convert the electrostatic signal sent by the second detection element 3 into a first voltage signal. Here, the electrostatic signal is a pulse current signal, and correspondingly, the first voltage signal is a pulse voltage signal.

[0074] The first amplifier circuit 522 is used to amplify the first voltage signal. Specifically, the first amplifier circuit 522 is used to amplify and enhance the gain of the first voltage signal and shape its waveform. The first amplifier circuit 522 can be a single-stage amplifier circuit or a multi-stage amplifier circuit, depending on the overall requirements for gain, bandwidth, and signal quality in the actual application.

[0075] The peak detection circuit 523 detects the amplified first voltage signal until it reaches the first target voltage and then transmits the first target voltage to the second conversion circuit 524. That is, the peak detection circuit 523 continuously captures the pulse voltage signal (first voltage signal) transmitted by the first amplification circuit 522, determines the peak value of the pulse voltage signal as the first target voltage, and transmits the first target voltage to the second conversion circuit 524. In other words, the first target voltage output by the peak detection circuit 523 is a stable DC voltage.

[0076] The second conversion circuit 524 is used to convert the first target voltage into a first current signal. The first current signal corresponds one-to-one with the dust concentration, thus the dust concentration in the dust-laden gas can be obtained based on the first current signal. Specifically, the second conversion circuit 524 is a current loop chip (such as XTR115), which can convert the first target voltage into a standard 4-20mA current signal output.

[0077] To ensure stable dust concentration measurement in complex industrial environments, the entire concentration signal processing link involved in the concentration processing module 52 is placed in a fully shielded metal shell (i.e., both the monitoring tube 1 and the shell 54 are metal parts and grounded), and anti-interference measures such as power isolation and active low-pass filters can also be adopted.

[0078] In some embodiments, see Figure 2 The concentration processing module 52 may further include a second amplification circuit 525, which is disposed between the peak detection circuit 523 and the second conversion circuit 524, and is used to amplify the first voltage signal sent by the peak detection circuit 523. The first amplification circuit 522 is a two-stage amplification circuit, and the second amplification circuit 525 is a single-stage amplification circuit.

[0079] Figure 3 This is a schematic diagram of the temperature processing module of the data processor provided according to an embodiment of this application.

[0080] See Figure 3 The temperature processing module 53 may include a power supply regulator circuit 531, a Wheatstone bridge circuit 532, a differential amplifier circuit 533, and a current drive circuit 534 connected in sequence.

[0081] The power supply regulator circuit 531 is connected to the Wheatstone bridge circuit 532 and is used to supply power to the Wheatstone bridge circuit 532, the differential amplifier circuit 533, and the current drive circuit 534. Specifically, the power supply regulator circuit 531 can convert the +24VDC power supply to a stable +5V to power the subsequent circuits.

[0082] The Wheatstone bridge circuit 532 is connected to the third sensing element 4 and converts the resistance signal sent by the third sensing element 4 into a second voltage signal. Specifically, when the third sensing element 4 comes into contact with dusty gas, the resistance value of the third sensing element 4 changes, causing the Wheatstone bridge circuit 532 to become unbalanced. At the same time, the Wheatstone bridge circuit 532 outputs a temperature-dependent millivolt-level differential voltage (i.e., the second voltage signal).

[0083] The differential amplifier circuit 533 amplifies the second voltage signal and performs common-mode rejection to obtain the second target voltage. The current drive circuit 534 converts the second target voltage into a second current signal. Specifically, the current drive circuit 534 can linearly convert the second target voltage into a standard 4-20mA current signal. The second current signal corresponds one-to-one with the temperature, meaning the temperature of the dust-laden gas can be obtained based on the second current signal.

[0084] To ensure stable temperature measurement of dust-laden gas in complex industrial environments, the entire signal processing link involving the temperature processing module 53 can be enhanced with filter capacitors and ground isolation to improve anti-interference capabilities.

[0085] In some embodiments, the housing 54 of the data processor 5 is provided with a local digital tube or LCD screen. After the speed processing module 51, concentration processing module 52, and temperature processing module 53 synchronously acquire, calculate, and process the three signals, the determined flow rate, temperature, and concentration values ​​can be displayed in real time on the local digital tube or LCD screen.

[0086] In some embodiments, the first detection element 2, the second detection element 3, and the third detection element 4 are connected to different processing modules of the data processor 5 via signal lines. (See also...) Figure 1 The monitoring tube 1 has an opening that communicates with the inside of the monitoring tube 1. The dust measuring device 100 also includes a connecting tube 6 and a fixed base 7.

[0087] A fixed base 7 is disposed on the outside of the monitoring tube 1 and is fixedly connected to the monitoring tube 1 at the opening. The fixed base 7 is provided with a channel communicating with the opening. The connecting tube 6 passes through the channel and the opening and is connected to the fixed base 7. The third detection element 4 is disposed inside the connecting tube 6 and partially extends into the monitoring tube 1. The signal lines connected to the first detection element 2, the second detection element 3 and the third detection element 4 pass through the connecting tube 6 to connect to the data processor 5.

[0088] In some embodiments, see Figure 1 The dust measuring device 100 also includes a sealing element 8, through which the third detection element 4 is sealed to the inner wall of the connecting pipe 6. Preferably, the sealing element 8 can be made of high-temperature resistant and aging-resistant rubber or silicone.

[0089] In some embodiments, the monitoring tube 1, housing 54, connecting tube 6, and fixed base 7 are all metal components and grounded, forming a continuous electromagnetic shield to achieve electromagnetic shielding. Of course, in addition to electromagnetic shielding, power isolation, ground separation, and filtering circuits can also be superimposed on the dust measuring device 100 to further effectively suppress electromagnetic interference in industrial environments.

[0090] This application also provides a dust explosion-proof control system, which includes the dust measuring device 100 and controller described in any of the above embodiments. This dust explosion-proof control system can be integrated into a dust removal system and can be used for dust removal in dust removal pipelines, combustion furnaces, and flues. The controller of this dust explosion-proof control system can perform explosion-proof control (such as early warning or dust removal closed-loop control) based on the flow rate, temperature, and dust concentration of the dust-laden gas monitored by the dust measuring device 100.

[0091] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A dust measuring device, characterized in that, include: The monitoring tube (1) is used to transport dust-laden gas; The first detection element (2) is disposed on the inner wall of the monitoring tube (1) and is used to sense the electrostatic signal of dust in the dust-laden gas at the first position. The second detection element (3) is disposed on the inner wall of the monitoring tube (1) and spaced apart from the first detection element (2), and is used to sense the electrostatic signal of dust in the dust-laden gas at the second position; The third detection element (4) is at least partially disposed inside the monitoring tube (1) and is used to generate a resistance signal when in contact with dust-laden gas; as well as The data processor (5) is connected to the first detection element (2), the second detection element (3), and the third detection element (4); The data processor (5) is configured to determine the flow rate of the dust-laden gas based on the time difference between the electrostatic signals sent by the first detection element (2) and the second detection element (3), and to determine the dust concentration in the dust-laden gas based on the electrostatic signals sent by the first detection element (2) and / or the second detection element (3), and to determine the temperature of the dust-laden gas based on the resistance signal sent by the third detection element (4).

2. The dust measuring device according to claim 1, characterized in that, The second detection element (3) is located downstream of the first detection element (2) along the flow direction of the dust-laden gas, and the third detection element (4) is located downstream of the second detection element (3) along the flow direction of the dust-laden gas. The data processor (5) is configured to determine the flow rate of the dust-laden gas based on the time difference between the electrostatic signals sent by the first detection element (2) and the second detection element (3) and the distance between the first detection element (2) and the second detection element (3) in the flow direction of the dust-laden gas, and is configured to determine the dust concentration in the dust-laden gas based on the electrostatic signal sent by the second detection element (3).

3. The dust measuring device according to claim 2, characterized in that, The data processor (5) includes a speed processing module (51), a concentration processing module (52), a temperature processing module (53), and a housing (54) that houses the speed processing module (51), the concentration processing module (52), and the temperature processing module (53). The speed processing module (51) is connected to the first detection element (2) and the second detection element (3), and is configured to determine the flow rate of the dust-laden gas based on the time difference of the electrostatic signals sent by the first detection element (2) and the second detection element (3) and the distance between the first detection element (2) and the second detection element (3) in the flow direction of the dust-laden gas. The concentration processing module (52) is connected to the second detection element (3) and is configured to determine the dust concentration in the dust-laden gas based on the electrostatic signal sent by the second detection element (3); The concentration processing module (52) is connected to the third detection element (4) and is configured to determine the temperature of the dust-laden gas based on the resistance signal sent by the third detection element (4).

4. The dust measuring device according to claim 3, characterized in that, The concentration processing module (52) includes a first conversion circuit (521), a first amplification circuit (522), a peak detection circuit (523), and a second conversion circuit (524) connected in sequence. The first conversion circuit (521) is connected to the second detection element (3) and is used to convert the electrostatic signal sent by the second detection element (3) into a first voltage signal; the first amplification circuit (522) is used to amplify the first voltage signal. The peak detection circuit (523) is used to detect the amplified first voltage signal until the first voltage signal reaches the first target voltage and then transmits the first target voltage to the second conversion circuit (524). The second conversion circuit (524) is used to convert the first target voltage into a first current signal. The first current signal corresponds one-to-one with the dust concentration, so that the dust concentration in the corresponding dust-laden gas can be obtained based on the first current signal.

5. The dust measuring device according to claim 3, characterized in that, The temperature processing module (53) includes a power supply regulator circuit (531), a Wheatstone bridge circuit (532), a differential amplifier circuit (533), and a current drive circuit (534) connected in sequence. The power supply regulator circuit (531) is connected to the Wheatstone bridge circuit (532) and is used to supply power to the Wheatstone bridge circuit (532). The Wheatstone bridge circuit (532) is connected to the third detection element (4) and converts the resistance signal sent by the third detection element (4) into a second voltage signal; The differential amplifier circuit (533) is used to process the second voltage signal and obtain the second target voltage, and the current drive circuit (534) is used to convert the second target voltage into a second current signal. The second current signal corresponds one-to-one with the temperature, so that the temperature of the corresponding dust-laden gas can be obtained based on the second current signal.

6. The dust measuring device according to claim 3, characterized in that, Along the flow direction of the dust-laden gas, the axial length of the first detection element (2) is The axial distance between the inlet end of the first detection element (2) and the inlet end of the second detection element (3) is ,and Between 0.15 and 0.

30.

7. The dust measuring device according to claim 3, characterized in that, Both the first detection element (2) and the second detection element (3) include an induction coil, which is a spiral ring electrode structure.

8. The dust measuring device according to any one of claims 3-7, characterized in that, The first detection element (2), the second detection element (3) and the third detection element (4) are connected to the data processor (5) via signal lines; The monitoring tube (1) has an opening that communicates with the inside of the monitoring tube (1), and the dust measuring device also includes a connecting tube (6) and a fixed base (7). The fixed base (7) is disposed on the outside of the monitoring tube (1) and is fixedly connected to the monitoring tube (1) at the opening. The fixed base (7) is provided with a channel communicating with the opening. The connecting tube (6) passes through the channel and the opening and is connected to the fixed base (7). The third detection element (4) is disposed inside the connecting tube (6) and partially extends into the monitoring tube (1), and the signal line connected to the first detection element (2), the second detection element (3) and the third detection element (4) passes through the connecting tube (6) to connect to the data processor (5).

9. The dust measuring device according to claim 8, characterized in that, The monitoring tube (1), the housing (54), the connecting tube (6), and the fixed base (7) are metal components and are grounded.

10. A dust explosion-proof control system, characterized in that, The invention includes a dust measuring device (100) as described in any one of claims 1-9 and a controller, wherein the controller performs explosion-proof control based on the flow rate, temperature and dust concentration in the dust-laden gas monitored by the dust measuring device.

Images