An extractable dust instrument with constant speed extraction function

Abstract

The utility model belongs to environmental monitoring equipment technical field relates to a kind of dust instrument with isocratic function, it includes: sampling tube, measuring unit and control unit;Sampling tube is provided with first flow detection piece, second flow detection piece and flue gas extraction part, flue gas extraction part extracts flue gas, first flow detection piece is used to detect flue gas flow in real time, and second flow detection piece is used to detect sampling flow in real time;Measuring unit is used to measure dust concentration;Control unit and first flow detection piece, second flow detection piece and flue gas extraction part are electrically connected.The utility model is compared by the real-time flow rate of flue gas and the real-time flow rate of sampling by the combination of first flow detection piece, second flow detection piece and control unit, and adjusts sampling flow rate by flue gas extraction part, so that sampling flow rate is equal to flue gas flow rate, to reduce the error between sampling flow rate and flue gas flow rate, improve the measurement accuracy of dust concentration.

Description

Technical Field

[0001] This utility model relates to the field of environmental monitoring equipment technology, specifically to an extractable dust meter with isokinetic extraction function. Background Technology

[0002] With increasingly stringent environmental regulations on industrial flue gas emission monitoring, the measurement accuracy of extraction dust meters, as a core component of continuous flue gas monitoring systems, directly impacts the effectiveness of pollution control. Currently, most mainstream extraction dust meters employ a constant-speed extraction method to collect flue gas samples, meaning the extraction pump operates at a constant speed, resulting in a fixed sampling flow rate.

[0003] However, in actual working conditions, the flue gas velocity flues frequently with the production load. Measuring dust concentration using a constant-speed sampling method has a fundamental measurement error: when the sampling speed is greater than the flue gas velocity, a negative pressure zone is formed at the sampling nozzle, and the airflow accelerates into the sampling tube. However, large dust particles in the flue gas cannot follow the deflection of the airflow due to inertia and still move along the original trajectory, resulting in the dust concentration of the collected sample being lower than the true value. When the sampling speed is less than the flue gas velocity, the airflow stagnates at the sampling nozzle, and dust is deposited on the tube wall due to the turbulent settling effect, causing the dust concentration of the collected sample to be higher than the true value. Utility Model Content

[0004] To address the fundamental measurement error inherent in the method of measuring dust concentration using a constant-speed extraction mode, where flue gas velocity fluctuates frequently with production load in actual working conditions, this invention provides an extraction-type dust meter with constant-speed extraction function.

[0005] This utility model relates to an extraction-type dust meter with constant velocity extraction function. It detects the real-time flow rate of flue gas using a first flow detection element and the real-time flow rate of the sampled gas using a second flow detection element. The control unit combines the real-time flow rate of the flue gas and the real-time flow rate of the sampled gas to calculate their real-time velocity. The control unit compares the real-time velocity of the flue gas and the real-time velocity of the sampled gas, and adjusts the sampling velocity by adjusting the flow rate of the flue gas extracted by the extraction element, making the sampling velocity equal to the flue gas velocity. This reduces the error between the sampling velocity and the flue gas velocity, improving the accuracy of dust concentration measurement.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0007] A dust collector with isokinetic extraction function includes: a sampling tube, a measuring unit, and a control unit; the sampling tube is equipped with a first flow detection element, a second flow detection element, and a flue gas extraction element, the flue gas extraction element being connected to a chimney to extract flue gas, the first flow detection element being located at the inlet section of the sampling tube and connected to the flue gas extraction element, the first flow detection element being used to detect the flue gas flow rate in real time, the second flow detection element being located at the outlet section of the sampling tube and being used to detect the sampling flow rate in real time; the measuring unit being connected to the sampling tube, the measuring unit being used to measure the dust concentration in the flue gas; the control unit being electrically connected to the first flow detection element, the second flow detection element, and the flue gas extraction element.

[0008] Optionally, the first flow detection element is a venturi flow meter.

[0009] Optionally, one end of the Venturi flow meter is connected to the chimney, and the other end of the Venturi flow meter is connected to the flue gas extraction device.

[0010] Optionally, the extraction-type dust collector with isokinetic extraction function further includes: a heating device, which is installed on the sampling tube and is used to heat the flue gas in the sampling tube.

[0011] Optionally, the measurement unit includes: a flue gas concentration detector and a filter; the flue gas concentration detector is connected to the sampling tube, the flue gas concentration detector emits a light beam into the sampling tube, and obtains the dust concentration in the flue gas by measuring the intensity of the light beam; the filter is connected to the flue gas concentration detector, the plane of the filter has an angle with the axis of the sampling tube, and the filter is used to filter out stray light outside the preset wavelength range.

[0012] Optionally, the angle between the plane of the filter and the axis of the sampling tube is 90°.

[0013] Optionally, the measurement unit further includes a support frame, which is connected to the sampling tube, and the filter is mounted on the support frame.

[0014] Optionally, the support frame has a slot, and the filter is placed in the slot.

[0015] Optionally, the extraction-type dust meter with isokinetic extraction function further includes: a display unit, which is electrically connected to the control unit, and displays flue gas flow rate, sampling flow rate and dust concentration data in real time.

[0016] In summary, this utility model has the following beneficial technical effects:

[0017] This utility model relates to an extraction-type dust meter with constant velocity extraction function. It detects the real-time flow rate of flue gas using a first flow detection element and the real-time flow rate of the sampled gas using a second flow detection element. The control unit combines the real-time flow rate of the flue gas and the real-time flow rate of the sampled gas to calculate their real-time velocity. The control unit compares the real-time velocity of the flue gas and the real-time velocity of the sampled gas, and adjusts the sampling velocity by adjusting the flow rate of the flue gas extracted by the extraction element, making the sampling velocity equal to the flue gas velocity. This reduces the error between the sampling velocity and the flue gas velocity, improving the accuracy of dust concentration measurement. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the extraction dust meter with constant velocity extraction function of this utility model.

[0019] Figure 2 This is a schematic diagram of the sampling unit of the extraction-type dust meter with constant velocity extraction function of this utility model.

[0020] Explanation of reference numerals in the attached drawings: 1. Display unit; 2. Measurement unit; 3. Heating device; 4. Control unit; 5. Filter; 6. Sampling tube. Detailed Implementation

[0021] The technical solution of this utility model will be further explained and described below with reference to the accompanying drawings and embodiments, but this utility model is not limited to the embodiments described below.

[0022] Reference Figure 1 and Figure 2 This utility model provides a dust collector with isokinetic extraction function, comprising: a sampling tube 6, a measuring unit 2, and a control unit 4; the sampling tube 6 is equipped with a first flow rate detector, a second flow rate detector, and a flue gas extraction component, the flue gas extraction component being connected to a chimney to extract flue gas; the first flow rate detector is located at the inlet section of the sampling tube 6 and connected to the flue gas extraction component, and is used to detect the flue gas flow rate in real time; the second flow rate detector is located at the outlet section of the sampling tube 6 and is used to detect the sampling flow rate in real time; the measuring unit 2 is connected to the sampling tube 6 and is used to measure the dust concentration in the flue gas; the control unit 4 is electrically connected to the first flow rate detector, the second flow rate detector, and the flue gas extraction component, and is used to compare the real-time flow rate of the flue gas with the real-time flow rate of the sampled gas and adjust the sampling flow rate of the flue gas extraction component in real time. The control unit 4 is a controller, specifically a Siemens SIMATIC S7-1200 controller. The measuring unit adopts the measuring structure of a commercially available extraction dust meter, which is a technology well known to those skilled in the art, and therefore will not be described in detail here.

[0023] Specifically, the first flow detection element can be a venturi tube flow meter, a Pitot tube, or an ultrasonic flow meter, all of which fall within the protection scope of this utility model; the second flow detection element can be a thermal flow meter, a differential pressure flow meter, or a vortex flow meter, all of which fall within the protection scope of this utility model.

[0024] Specifically, the flue gas extraction component can be a blower or an air pump, both of which fall within the protection scope of this utility model; the control unit adjusts the flow rate of the extracted flue gas by controlling the speed of the blower or the speed of the air pump.

[0025] Specifically, the measuring unit 2 can be a dust concentration sensor, which measures the dust concentration in the flue gas.

[0026] The extraction-type dust meter with isokinetic extraction function may further include: a heating device 3, which is installed on the sampling tube 6 and is used to heat the flue gas in the sampling tube 6. That is, the flue gas in the sampling tube 6 is heated by the heating device 3, and then the dust concentration in the heated flue gas is measured by the measuring unit 2. This configuration facilitates the evaporation of moisture in the flue gas, thereby preventing dust in the flue gas from agglomerating and causing blockage, while ensuring that the flue gas is at a high temperature during the measurement process, thus improving the accuracy and reliability of the measurement.

[0027] The extraction-type dust collector with isokinetic extraction function may further include: a display unit 1, which is electrically connected to the control unit 4. The display unit 1 displays real-time data on flue gas flow rate, sampling flow rate, and dust concentration. The display unit 1 can be a touch screen or a wireless transmission device, both of which fall within the protection scope of this utility model. This configuration facilitates operators' intuitive monitoring of flue gas flow rate, sampling flow rate, and dust concentration data.

[0028] Reference Figure 1 and Figure 2 In some embodiments, the second flow detection element is a thermal flow meter, which is installed at the outlet section of the sampling tube 6. This configuration allows for direct contact measurement of the sample using the thermal flow meter, ensuring timely measurement and improving the accuracy of the results. Furthermore, installing the thermal flow meter at the outlet section of the sampling tube 6 avoids the turbulence effects of a venturi flow meter, further enhancing the accuracy of the measurement results.

[0029] Reference Figure 1 and Figure 2 In some embodiments, the first flow detection device is a venturi flow meter. One end of the venturi flow meter is connected to the chimney, and the other end of the venturi flow meter is connected to the flue gas extraction device. When the flue gas flows to the throat of the venturi flow meter, it accelerates rapidly. The kinetic energy generated by the high-speed flow washes away the dust particles in the flue gas, thereby preventing the dust particles from clogging the venturi flow meter.

[0030] The angle between the axial direction of the Venturi flowmeter and the axial direction of the sampling tube 6 can be 0°, 30°, 60°, 90°, etc., all of which fall within the protection scope of this utility model. When the angle between the axial direction of the Venturi flowmeter and the axial direction of the sampling tube 6 is 0°, turbulence is avoided, and the measurement accuracy of flue gas velocity is improved.

[0031] Reference Figure 1 and Figure 2 In some embodiments, the measuring unit may include: a flue gas concentration detector and a filter 5; the flue gas concentration detector is connected to a sampling tube 6, emits a light beam into the sampling tube 6, and obtains the dust concentration in the flue gas by measuring the intensity of the light beam; the filter 5 is connected to the flue gas concentration detector, and the plane of the filter 5 forms an angle with the axis of the sampling tube 6, the filter 5 is used to filter out stray light outside the preset wavelength range. Specifically, the photoelectric smoke detector or the dust concentration monitor of the flue gas concentration detector are both within the protection scope of this utility model. The flue gas concentration detector uses the principle of light scattering to measure the dust concentration in the flue gas, which is a conventional technology well known to those skilled in the art, and therefore will not be described in detail here.

[0032] Specifically, the angle between the plane of the filter 5 and the axis of the sampling tube 6 can be 0°, 60°, 90°, etc., all of which fall within the protection scope of this utility model. When the angle between the plane of the filter 5 and the axis of the sampling tube 6 is 90°, the filter 5 filters out the most stray light outside the preset wavelength range, thereby improving the accuracy of dust concentration measurement in flue gas.

[0033] The extraction-type dust collector with isokinetic extraction function also includes: a support frame, which is connected to the inner wall of the sampling tube 6, and a filter 5 mounted on the support frame. This configuration, with the support frame supporting the filter 5, improves the stability of the filter 5.

[0034] The support frame can be provided with a slot, and the filter 5 is placed in the slot. This design facilitates the installation of the filter 5 and makes operation convenient.

[0035] The working principle of this novel extraction-type dust collector with isokinetic extraction function is as follows: The flue gas extraction component draws the flue gas from the chimney to the sampling tube 6; at the inlet section of the sampling tube 6, the first flow detection component detects the real-time flow rate of the flue gas and outputs the flue gas flow rate signal to the control unit 4; at the outlet section of the sampling tube 6, the second flow detection component detects the real-time sampled flow rate and outputs the sampled flow rate signal to the control unit 4; the control unit 4 combines the real-time flow rate of the flue gas and the real-time sampled flow rate to calculate the real-time velocity of the flue gas and the real-time velocity of the sampled flow rate, and compares the real-time velocity of the flue gas and the real-time velocity of the sampled flow rate. Based on the comparison result, the control unit calculates the flue gas extraction flow rate required by the flue gas extraction component when the real-time velocity of the flue gas and the real-time velocity of the sampled flow rate are equal. Then, the control unit adjusts the rotation speed of the flue gas extraction component to adjust the flue gas extraction flow rate, ultimately achieving isokinetic extraction of the flue gas.

[0036] The preferred embodiments of this utility model are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape, and principle of this utility model should be included within the scope of protection of this utility model.

Claims

1. A dust collector with constant velocity extraction function, characterized in that, include: A sampling tube (6) is provided with a first flow detection element, a second flow detection element and a flue gas extraction element. The flue gas extraction element is connected to a chimney to extract flue gas. The first flow detection element is located at the inlet section of the sampling tube (6) and is connected to the flue gas extraction element. The first flow detection element is used to detect the flue gas flow rate in real time. The second flow detection element is located at the outlet section of the sampling tube (6) and is used to detect the sampling flow rate in real time. The measuring unit (2) is connected to the sampling tube (6) and is used to measure the dust concentration in the flue gas; The control unit (4) is electrically connected to the first flow detection element, the second flow detection element, and the flue gas extraction element.

2. The extraction-type dust collector with constant velocity extraction function according to claim 1, characterized in that: The first flow detection device is a venturi flow meter.

3. The extraction-type dust collector with constant velocity extraction function according to claim 2, characterized in that: One end of the Venturi flow meter is connected to the chimney, and the other end of the Venturi flow meter is connected to the flue gas extraction device.

4. The extraction-type dust collector with constant velocity extraction function according to claim 1, characterized in that, The extraction-type dust collector with isokinetic extraction function also includes: Heating device (3) is installed on the sampling tube (6) and is used to heat the flue gas in the sampling tube (6).

5. The extraction-type dust collector with constant velocity extraction function according to claim 3 or 4, characterized in that, The measurement unit includes: A flue gas concentration detector is connected to the sampling tube (6). The flue gas concentration detector emits a light beam into the sampling tube (6) and obtains the dust concentration in the flue gas by measuring the intensity of the light beam. A filter (5) is connected to the flue gas concentration detector. The plane of the filter (5) has an angle with the axis of the sampling tube (6). The filter (5) is used to filter out stray light outside the preset wavelength range.

6. The extraction-type dust collector with constant velocity extraction function according to claim 5, characterized in that: The angle between the plane of the filter (5) and the axis of the sampling tube (6) is 90°.

7. The extraction-type dust collector with constant velocity extraction function according to claim 5, characterized in that, The measurement unit also includes: A support frame is connected to the sampling tube (6), and the filter (5) is mounted on the support frame.

8. The extraction-type dust collector with isokinetic extraction function according to claim 7, characterized in that: The support frame has a slot, and the filter (5) is placed in the slot.

9. The extraction-type dust collector with constant velocity extraction function according to claim 1, characterized in that, The extraction-type dust collector with isokinetic extraction function also includes: The display unit (1) is electrically connected to the control unit (4) and displays the flue gas flow rate, sampling flow rate and dust concentration data in real time.

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