Multifunctional cutter collecting efficiency evaluation device and method

Abstract

The invention provides a multifunctional device and method for evaluating the trapping efficiency of a cutter, and the device comprises a uniform mixing cabin which is used for storing different types of particulate particles and atomizing the particulate particles to form aerosol; a rotatable Y-shaped pipe, a cutter to be evaluated and a reference passage are arranged in the measuring cabin, the first end of the Y-shaped pipe is communicated with the uniform mixing cabin, and when the trapping efficiency of the cutter is evaluated by using a shunt method, the Y-shaped pipe is rotated to enable the second end of the Y-shaped pipe to be communicated with the input end of the cutter to be evaluated, and the third end of the Y-shaped pipe is communicated with the input end of the reference passage; when a static box method is used for evaluating the trapping efficiency of the cutter, the Y-shaped pipe is rotated to enable the second end of the Y-shaped pipe not to be communicated with the input end of the cutter to be evaluated, and the third end of the Y-shaped pipe not to be communicated with the input end of the reference passage. According to the invention, by rotating the Y-shaped pipe, a shunting method and a static box method can be flexibly switched, and the testing of the two methods can be completed without replacing equipment, so that the testing convenience and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental monitoring, and in particular, to a multifunctional evaluation device and method for the capture efficiency of a cutter. Background Art

[0002] With the acceleration of the industrialization process and the expansion of the urbanization scale, the particulate matter pollution problem in the atmosphere has become increasingly serious. In particular, fine particulate matter with a particle size less than 2.5 micrometers (PM2.5), due to its small particle size and large specific surface area, is prone to adsorbing toxic and harmful substances, posing a serious threat to human health. PM2.5 can enter the human body through the respiratory system, penetrate deep into the lungs and even enter the blood circulation, causing health problems such as respiratory diseases, cardiovascular diseases, and lung cancer. Therefore, the monitoring and control of PM2.5 have become an important topic in the fields of environmental protection and public health.

[0003] In recent years, with the country's emphasis on PM2.5 monitoring, particulate matter monitoring technologies such as light scattering and beta-ray have developed rapidly. However, the collection of environmental particulate matter and the separation of different particle sizes are key steps affecting the accuracy of detection results. To improve the accuracy of detection results, it is usually necessary to screen the aerosol through a cutter before it enters the instrument monitoring unit. The internal structure design of the cutter determines the particles of different sizes that can pass through it, thereby achieving the classification and screening of particulate matter. The main methods for evaluating the capture efficiency of common cutters are the shunt method and the static chamber method. The shunt method and the static chamber method require the use of different capture efficiency evaluation devices to complete the measurement respectively, increasing the complexity and cost of the measurement. Summary of the Invention

[0004] To solve the above problems, the purpose of the present invention is to provide a multifunctional evaluation device and method for the capture efficiency of a cutter.

[0005] A multifunctional evaluation device for the capture efficiency of a cutter includes:

[0006] A mixing chamber 2 for storing aerosol formed by atomizing particulate matter particles of different types;

[0007] A measurement chamber, in which a rotatable Y-shaped tube 3, a cutter to be evaluated 6, and a reference path 5 are arranged. The first end of the Y-shaped tube 3 is connected to the mixing chamber 2. When using the shunt method to evaluate the capture efficiency of the cutter, rotate the Y-shaped tube 3 so that the second end of the Y-shaped tube 3 is connected to the input end of the cutter to be evaluated 6, and the third end of the Y-shaped tube 3 is connected to the input end of the reference path 5;

[0008] When using the static chamber method to evaluate the capture efficiency of the cutter, rotate the Y-shaped tube 3 so that the second end of the Y-shaped tube 3 is no longer connected to the input end of the cutter to be evaluated 6, and the third end of the Y-shaped tube 3 is no longer connected to the input end of the reference path 5;

[0009] The output end of the cutter 6 to be evaluated and the output end of the reference path 5 are both connected to the particle size spectrometer.

[0010] Preferably, it further includes: an atomizer 1, connected to the mixing chamber 2, for atomizing different types of particulate matter particles to form an aerosol.

[0011] Preferably, it further includes: a rotating bracket 7, connected to the Y-shaped tube 3, for adjusting the rotation angle of the Y-shaped tube 3.

[0012] The present invention also provides a method for evaluating the capture efficiency of a cutter, including:

[0013] Step 1: Rotate the Y-shaped tube so that the second end of the Y-shaped tube is connected to the input end of the cutter to be evaluated, and the third end of the Y-shaped tube is connected to the input end of the reference path;

[0014] Step 2: Use the particle size spectrometer to detect the change in the concentration of particulate matter before and after the operation of the cutter, and calculate the capture efficiency obtained by the split flow method;

[0015] Step 3: Rotate the Y-shaped tube so that the second end of the Y-shaped tube is no longer connected to the input end of the cutter to be evaluated, and the third end of the Y-shaped tube is no longer connected to the input end of the reference path;

[0016] Step 4: Use the particle size spectrometer to detect the change in the concentration of particulate matter before and after the operation of the cutter, and calculate the capture efficiency obtained by the static chamber method.

[0017] Preferably, in the said Step 2: Use the particle size spectrometer to detect the change in the concentration of particulate matter before and after the operation of the cutter, and calculate the capture efficiency obtained by the split flow method, including:

[0018] Step 2.1: Taking the particle size as the abscissa and the capture efficiency as the ordinate, fit to obtain the capture efficiency curve;

[0019] Step 2.2: Obtain the aerodynamic equivalent particle size corresponding to a capture efficiency of 50% and use it as the performance parameter measured by the split flow method;

[0020] Step 2.3: Calculate the geometric standard deviation measured by the split flow method according to the capture efficiency curve.

[0021] Preferably, in Step 2.3, the calculation formula for the geometric standard deviation is:

[0022]

[0023] where Da 16 、Da 50 、Da 84respectively represent the aerodynamic equivalent diameters corresponding to the capture efficiencies of 16%, 50%, and 84%, and σ g1 represents the first geometric standard deviation measured using the split-flow method, and σ g2 represents the second geometric standard deviation measured using the split-flow method.

[0024] Preferably, in step 4: detecting the change in the particulate matter concentration before and after the operation of the cutter using a particle size spectrometer, and calculating the capture efficiency obtained by the static chamber method, including:

[0025] Step 4.1: With the particle size as the abscissa and the capture efficiency as the ordinate, fitting to obtain a capture efficiency curve;

[0026] Step 4.2: Obtain the aerodynamic equivalent diameter corresponding to a capture efficiency of 50% and use it as a performance parameter measured by the static chamber method;

[0027] Step 4.3: Calculate the geometric standard deviation measured by the static chamber method according to the capture efficiency curve.

[0028] Preferably, in step 4.3, the calculation formula for the geometric standard deviation is:

[0029]

[0030] where Da 16 、Da 50 、Da 84 respectively represent the aerodynamic equivalent diameters corresponding to the capture efficiencies of 16%, 50%, and 84%, and σ g3 represents the first geometric standard deviation measured using the static chamber method, and σ g4 represents the second geometric standard deviation measured using the static chamber method.

[0031] The beneficial effects of a multifunctional evaluation device and method for the capture efficiency of a cutter provided by the present invention are as follows: Compared with the prior art, by rotating the Y-shaped tube, the present invention can flexibly switch between the split-flow method and the static chamber method, and complete the tests of the two methods without replacing the equipment, improving the convenience and efficiency of the test.

[0032] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given, and in conjunction with the accompanying drawings, the detailed description is as follows. Brief Description of the Drawings

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0034] Figure 1 Fig. shows a schematic diagram of a multifunctional evaluation device for the capture efficiency of a cutter provided by the present invention;

[0035] Figure 2 Fig. shows a comparison chart of the capture efficiency curves of the inlet cutter provided by the present invention;

[0036] Figure 3 Fig. shows a comparison chart of the capture efficiency curves of the domestic cutter provided by the present invention. Detailed implementation manners

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0038] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0039] In the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Please refer to Figure 1 , a multifunctional evaluation device for the capture efficiency of a cutter, comprising:

[0041] An atomizer 1, which is connected to a mixing chamber 2 and is used for atomizing different types of particulate matter particles to form an aerosol.

[0042] A measurement chamber, in which a rotatable Y-shaped tube 3, a cutter to be evaluated 6 and a reference path 5 are provided. The first end of the Y-shaped tube 3 is connected to the mixing chamber 2. When evaluating the capture efficiency of the cutter using the split flow method, the Y-shaped tube 3 is rotated so that the second end of the Y-shaped tube 3 is connected to the input end of the cutter to be evaluated 6, and the third end of the Y-shaped tube 3 is connected to the input end of the reference path 5.

[0043] When evaluating the capture efficiency of the cutter using the static chamber method, the Y-shaped tube 3 is rotated so that the second end of the Y-shaped tube 3 is no longer connected to the input end of the cutter to be evaluated 6, and the third end of the Y-shaped tube 3 is no longer connected to the input end of the reference path 5. The output ends of the cutter to be evaluated 6 and the reference path 5 are both connected to a particle size spectrometer. A rotating bracket 7, which is connected to the Y-shaped tube 3 and is used for adjusting the rotation angle of the Y-shaped tube 3.

[0044] The present invention also provides a method for evaluating the capture efficiency of a cutter, including:

[0045] Step 1: Rotate the Y-shaped tube so that the second end of the Y-shaped tube is connected to the input end of the cutter to be evaluated, and the third end of the Y-shaped tube is connected to the input end of the reference path.

[0046] Step 2: Use a particle size spectrometer to detect the change in the concentration of particulate matter before and after the cutter operates, and calculate the capture efficiency obtained by using the split flow method.

[0047] Further, the step 2 includes:

[0048] Step 2.1: With the particle size as the abscissa and the capture efficiency as the ordinate, fit to obtain a capture efficiency curve.

[0049] Step 2.2: Obtain the aerodynamic equivalent particle size corresponding to a capture efficiency of 50% and use it as a performance parameter measured by the split flow method.

[0050] Step 2.3: Calculate the geometric standard deviation measured by the split flow method according to the capture efficiency curve.

[0051] In step 2.3, the calculation formula for the geometric standard deviation is:

[0052]

[0053] Wherein, Da 16 、Da 50 、Da 84 respectively represent the aerodynamic equivalent particle sizes corresponding to capture efficiencies of 16%, 50%, and 84%, σg1 represents the first geometric standard deviation measured using the shunt method, σ g2 represents the second geometric standard deviation measured using the shunt method.

[0054] Step 3: Rotate the Y-shaped tube so that the second end of the Y-shaped tube is no longer in communication with the input end of the cutter to be evaluated, and the third end of the Y-shaped tube is no longer in communication with the input end of the reference path;

[0055] Step 4: Detect the change in the particulate matter concentration before and after the operation of the cutter using a particle size spectrometer, and calculate the capture efficiency obtained using the static chamber method.

[0056] Further, the said Step 4 includes:

[0057] Step 4.1: With the particle size as the abscissa and the capture efficiency as the ordinate, fit to obtain the capture efficiency curve;

[0058] Step 4.2: Obtain the aerodynamic equivalent particle size corresponding to a capture efficiency of 50% and use it as the performance parameter measured by the static chamber method;

[0059] Step 4.3: Calculate the geometric standard deviation measured by the static chamber method according to the capture efficiency curve.

[0060] In Step 4.3, the calculation formula for the geometric standard deviation is:

[0061]

[0062] where Da 16 , Da 50 , Da 84 respectively represent the aerodynamic equivalent particle sizes corresponding to capture efficiencies of 16%, 50%, and 84%, σ g3 represents the first geometric standard deviation measured using the static chamber method, σ g4 represents the second geometric standard deviation measured using the static chamber method.

[0063] In order to evaluate the difference in the measurement results between the static chamber method and the shunt method, the present invention evaluated two cutters using the static chamber method and the shunt method respectively by rotating the Y-shaped tube, and its capture efficiency curve is as Figures 2-3 shown. It can be seen that the two curves are almost coincident and the consistency is very good. The specific data of the test results are shown in Table 1.

[0064] Table 1

[0065]

[0066] The Da 50 deviation between the two cases is within 0.02 μm. After statistical analysis, Da 50The p-values of the significance levels are 0.0601 and 0.1012 respectively, both greater than 0.05, indicating no significant difference. The relative standard deviations of the capture efficiencies obtained by the two methods are shown in Table 2, all within 10%, indicating that whether the Y-shaped pipeline is installed has little effect on the evaluation results of the cutter.

[0067] Table 2

[0068]

[0069] It should be noted that the factors affecting the uncertainty of the capture efficiency Da 50 of the cutter are mainly three aspects, namely the uncertainty of the capture efficiency measurement, the uncertainty introduced by the fitting of the capture efficiency curve, and the uncertainty introduced by the particle size. Based on these three aspects, it is necessary to comprehensively consider the capture efficiency measurement model, measurement repeatability and cutter evaluation device, the national certified single-dispersed particulate matter standard substance for PM2.5 cutters, and the uncertainty component introduced by using the Reverse Asymmetric Sigmoid Equation as the fitting curve, and finally obtain the expanded uncertainty U 50 of Da r = 4.5% (k = 2). When actually comparing the results of measuring the Da 50 of the PM2.5 cutter by the static chamber method and the shunt method, the influence introduced by the above uncertainty components has been taken into account.

[0070] In the present invention, by rotating the Y-shaped tube, the shunt method and the static chamber method can be flexibly switched, and the tests of the two methods can be completed without replacing the equipment, improving the convenience and efficiency of the test.

[0071] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technical solution that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. A multifunctional evaluation device for the trapping efficiency of a cutter, characterized in that, Comprising: A mixing chamber (2) for storing aerosol formed by atomizing particulate matter particles of different types; A measurement chamber, in which a rotatable Y-shaped tube (3), a cutter to be evaluated (6) and a reference path (5) are arranged. The first end of the Y-shaped tube (3) is communicated with the mixing chamber (2). When evaluating the collection efficiency of the cutter by the splitting method, rotate the Y-shaped tube (3) so that the second end of the Y-shaped tube (3) is communicated with the input end of the cutter to be evaluated (6), and the third end of the Y-shaped tube (3) is communicated with the input end of the reference path (5); When evaluating the collection efficiency of the cutter by the static chamber method, rotate the Y-shaped tube (3) so that the second end of the Y-shaped tube (3) is no longer communicated with the input end of the cutter to be evaluated (6), and the third end of the Y-shaped tube (3) is no longer communicated with the input end of the reference path (5); The output ends of the cutter to be evaluated (6) and the reference path (5) are both communicated with a particle size spectrometer.

2. A multifunctional cutter capture efficiency evaluation device according to claim 1, characterized in that Further comprising: An atomizer (1) communicated with the mixing chamber (2) for atomizing particulate matter particles of different types to form an aerosol.

3. A multifunctional cutter capture efficiency evaluation device according to claim 1, characterized in that, Further comprising: A rotating bracket (7) connected to the Y-shaped tube (3) for adjusting the rotation angle of the Y-shaped tube (3).

4. A method for evaluating the trapping efficiency of a cutter, characterized in that, Applied to a multifunctional evaluation device for the collection efficiency of a cutter described in any one of claims 1-3, comprising: Step 1: Rotate the Y-shaped tube so that the second end of the Y-shaped tube is communicated with the input end of the cutter to be evaluated, and the third end of the Y-shaped tube is communicated with the input end of the reference path; Step 2: Use a particle size spectrometer to detect the change in the concentration of particulate matter before and after the operation of the cutter, and calculate the collection efficiency obtained by the splitting method; Step 3: Rotate the Y-shaped tube so that the second end of the Y-shaped tube is no longer communicated with the input end of the cutter to be evaluated, and the third end of the Y-shaped tube is no longer communicated with the input end of the reference path; Step 4: Use a particle size spectrometer to detect the change in the concentration of particulate matter before and after the operation of the cutter, and calculate the collection efficiency obtained by the static chamber method.

5. The evaluation method for the capture efficiency of a cutter according to claim 4, characterized in that In the said Step 2: Use a particle size spectrometer to detect the change in the concentration of particulate matter before and after the operation of the cutter, and calculate the collection efficiency obtained by the splitting method, including: Step 2.1: Taking the particle size as the abscissa and the collection efficiency as the ordinate, fit to obtain a collection efficiency curve; Step 2.2: Obtain the aerodynamic equivalent particle size corresponding to a collection efficiency of 50% and use it as a performance parameter measured by the splitting method; Step 2.3: Calculate the geometric standard deviation measured by the splitting method according to the collection efficiency curve.

6. The evaluation method for the trapping efficiency of a cutter according to claim 5, wherein In Step 2.3, the calculation formula for the geometric standard deviation is: Among them, Da 16 , Da 50 , Da 84 respectively represent the aerodynamic equivalent diameters corresponding to the collection efficiencies of 16%, 50%, and 84%, and σ g1 represents the first geometric standard deviation measured by the splitting method, and σ g2 represents the second geometric standard deviation measured by the splitting method.

7. A method for evaluating the trapping efficiency of a cutter according to claim 4, characterized in that, The said Step 4: Use a particle size spectrometer to detect the change in the concentration of particulate matter before and after the operation of the cutter, and calculate the collection efficiency obtained by the static chamber method, including: Step 4.1: Taking the particle size as the abscissa and the collection efficiency as the ordinate, fit to obtain a collection efficiency curve; Step 4.2: Obtain the aerodynamic equivalent particle size corresponding to a collection efficiency of 50% and use it as a performance parameter measured by the static chamber method; Step 4.3: Calculate the geometric standard deviation measured by the static chamber method according to the collection efficiency curve.

8. A method for evaluating the trapping efficiency of a cutter according to claim 7, characterized in that In Step 4.3, the calculation formula for the geometric standard deviation is: Among them, Da 16 , Da 50 , Da 84 respectively represent the aerodynamic equivalent diameters corresponding to the capture efficiencies of 16%, 50%, and 84%, and σ g3 represents the first geometric standard deviation measured using the static chamber method, and σ g4 represents the second geometric standard deviation measured using the static chamber method.

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