Method for detecting the filtration efficiency of an ultra-high efficiency filter

Abstract

The present application relates to a kind of methods for detecting the filtering efficiency of ultra-high efficiency filter, establish the filtering efficiency calculation equation containing unknown coefficient for the ultra-high efficiency filter of the type to be detected, filtering efficiency calculation equation is used to characterize the relationship between the filtering efficiency of selected local area in the filtering plane of ultra-high efficiency filter and the overall filtering efficiency of ultra-high efficiency filter;The filtering efficiency data of selected local area in the filtering plane of ultra-high efficiency filter and the overall filtering efficiency data of ultra-high efficiency filter are obtained by carrying out multiple experiments to the ultra-high efficiency filter of the type to be detected, the unknown coefficient is solved using the data obtained by experiment to determine filtering efficiency calculation equation;For the ultra-high efficiency filter to be detected, the filtering efficiency of selected local area in the filtering plane thereof is detected, and the overall filtering efficiency of the ultra-high efficiency filter to be detected is calculated using filtering efficiency calculation equation.The present application can improve the speed and accuracy of filter efficiency detection.

Description

Technical Field

[0001] This invention relates to a method for detecting the filtration efficiency of an ultra-high efficiency filter. Background Technology

[0002] Ultra-high efficiency filters are mainly used to capture particles of 0.1μm and smaller, and are used in a variety of applications such as high-end manufacturing, aerospace, semiconductors, precision instruments and equipment, and nuclear energy.

[0003] In the traditional process of calculating filter efficiency, the entire filter needs to be scanned to obtain the overall efficiency, which is time-consuming and labor-intensive and not conducive to improving the overall detection efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a method for rapidly and accurately detecting the filtration efficiency of ultra-high efficiency filters.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for detecting the filtration efficiency of an ultra-high efficiency filter (UHEPA filter) is provided for testing the filtration efficiency of any model of UHEPA filter. The method comprises: establishing a filtration efficiency calculation equation containing unknown coefficients for the UHEPA filter of the model to be tested; the filtration efficiency calculation equation characterizes the relationship between the filtration efficiency of a selected local area in the filtration plane of the UHEPA filter and the overall filtration efficiency of the UHEPA filter; conducting multiple experiments on the UHEPA filter of the model to be tested to obtain filtration efficiency data of the selected local area in the filtration plane of the UHEPA filter and the overall filtration efficiency data of the UHEPA filter in each experiment; solving for the unknown coefficients using the experimental data to determine the filtration efficiency calculation equation; and for the UHEPA filter to be tested, detecting the filtration efficiency of the selected local area in its filtration plane, and calculating the overall filtration efficiency of the UHEPA filter to be tested using the filtration efficiency calculation equation.

[0007] The method for determining the selected local region for the filtration plane of the ultra-high efficiency filter of the model to be tested is as follows: the filtration plane of the ultra-high efficiency filter of the model to be tested is divided into p sub-regions. For each sub-region, an efficiency deviation coefficient is calculated, which characterizes the deviation between the filtration efficiency of the sub-region and the overall filtration efficiency of the ultra-high efficiency filter. The efficiency deviation coefficients are sorted in ascending order to obtain an efficiency deviation coefficient sequence. The sub-regions corresponding to the first q efficiency deviation coefficients in the efficiency deviation coefficient sequence are selected as the selected local regions, where p is an integer greater than or equal to 2, q is an integer greater than or equal to 1, and q < p.

[0008] The efficiency deviation coefficient k of the nth sub-region Deltan =K n 2 *K posn Where n is the number of the sub-region, K n K is the local efficiency factor of the nth sub-region. posn is the positional deviation factor for the nth sub-region.

[0009] K n =(f n -f All ) / f All f n f is the filtering efficiency value of the nth sub-region. All This refers to the overall filtration efficiency value of the ultra-high efficiency filter.

[0010] K posn =50%*k XPosn +50%*k YPosn k XPosn k represents the magnitude of the deviation in the X direction of the nth sub-region relative to the center of the filtration plane of the ultra-high efficiency filter. YPosn The magnitude of the deviation of the nth sub-region from the center of the filtration plane of the ultra-high efficiency filter in the Y direction.

[0011] k XPosn k YPosn The value range is 0 to 1.

[0012] Based on the magnitude of the deviation in the X and Y directions between the center of the nth sub-region and the center or edge of the ultra-high efficiency filter's filtration plane, k is interpolated. XPosn k YPosn .

[0013] Let there be g sub-regions from the edge to the center in the X direction of the filter plane of the ultra-high efficiency filter, and let the nth sub-region be the rth sub-region from the edge to the center in the X direction of the filter plane of the ultra-high efficiency filter. Then k XPosn =1.0*(r / g); Let there be h sub-regions from the edge to the center in the Y direction of the filter plane of the ultra-high efficiency filter, and the nth sub-region is the s-th sub-region from the edge to the center in the Y direction of the filter plane of the ultra-high efficiency filter, then k YPosn =1.0*(s / h).

[0014] The equation for calculating the filtration efficiency is: Where Y is the overall filtration efficiency of the ultra-high efficiency filter, i is the selected sub-region number, and x iFor the filtering efficiency of the selected i-th sub-region, k i is the coefficient corresponding to the selected i-th sub-region.

[0015] The ultra-high efficiency filter is divided into p sub-regions, which are arranged in an array of multiple rows and columns.

[0016] Based on the filtration efficiency calculation equation containing unknown coefficients, the experimental data is used to connect the equation system, and the equation system is transformed into a coefficient matrix. The coefficient matrix is ​​then transformed to obtain the step matrix, and finally the value of the unknown coefficient is obtained.

[0017] Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art: the present invention can improve the speed and accuracy of filter efficiency detection. Attached Figure Description

[0018] Appendix Figure 1 This is a schematic diagram of the filtration plane division of the ultra-high efficiency filter in this invention.

[0019] Appendix Figure 2 This is a schematic diagram of the position deviation factor distribution in this invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0021] Example 1: A method for detecting the filtration efficiency of an ultra-high efficiency filter (UHEPA filter) of any model is as follows:

[0022] Step 1: Establish a filtration efficiency calculation equation containing unknown coefficients for the model of ultra-high efficiency filter to be tested. The filtration efficiency calculation equation is used to characterize the relationship between the filtration efficiency of a selected local area in the filtration plane of the ultra-high efficiency filter and the overall filtration efficiency of the ultra-high efficiency filter.

[0023] 1. Local region selection

[0024] The principle followed in selecting the local area is to maximize its correlation with the overall efficiency of the filter, also known as the local characteristic efficiency of the filter. The following methods can be used to determine the selected local area for the filter plane of the ultra-high efficiency filter model to be tested:

[0025] 1) Divide the filter plane of the ultra-high efficiency filter to be tested into p (where p is an integer greater than or equal to 2) sub-regions. See attached... Figure 1As shown in this embodiment, the filter plane (top plane) of the rectangular ultra-high efficiency filter is divided into p (p=48) sub-regions arranged in a multi-row, multi-column array, with each sub-region also being rectangular. Simultaneously, two perpendicular directions are defined for the filter plane of the ultra-high efficiency filter: the X direction and the Y direction. For example, the length direction of the filter plane is the X direction, and the width direction is the Y direction.

[0026] 2) Calculate the efficiency deviation coefficient for each sub-region. This efficiency deviation coefficient represents the deviation between the filtration efficiency of the corresponding sub-region and the overall filtration efficiency of the ultra-high efficiency filter.

[0027] The efficiency deviation coefficient of the sub-region involves two aspects: filtration efficiency and location.

[0028] For the nth subregion (n is a positive integer less than or equal to p), K n Its local efficiency factor is the filtering efficiency value f obtained from the current test in the nth sub-region. n The overall filtration efficiency value f of the ultra-high efficiency filter All The deviation ratio, i.e., K n =(f n -f All ) / f All When calculating the efficiency deviation coefficient of the nth sub-region, it needs to be squared again, denoted as K. Deltan =K n *K n .

[0029] For the nth sub-region, K posn Its position deviation factor, K posn =50%*k XPosn +50%*k YPosn , where k XPosn k represents the magnitude of the deviation in the X direction of the center of the filter plane of the nth sub-region relative to the ultra-high efficiency filter. YPosn Characterizes the magnitude of the deviation in the Y direction of the center of the filter plane of the nth sub-region relative to the ultra-high efficiency filter.

[0030] For details, see attached. Figure 2 As shown, deviations at the edges generally have the greatest impact. Let k be the center of the filter plane of the ultra-high efficiency filter. XPosn / k YPosn The value of k is 0, while the value of k at the edge is 0. XPosn / k YPosn The value is 1, meaning the positional deviation decreases from the edge to the center. Let the initial value be 1 and the center value be 0. XPosn k YPosnThe values ​​of are all between 0 and 1. k can be interpolated based on the deviations in the X and Y directions from the center of the nth sub-region to the center or edge of the ultra-high efficiency filter's filtration plane. XPosn k YPosn Let there be g sub-regions from the edge to the center of the filter plane in the X direction of the ultra-high efficiency filter. Let the nth sub-region be the rth sub-region from the edge to the center of the filter plane in the X direction. Then k XPosn =1.0*(r / g); Let there be h sub-regions from the edge to the center of the filter plane in the Y direction of the ultra-high efficiency filter. The nth sub-region is the s-th sub-region from the edge to the center of the filter plane in the Y direction. Then k YPosn = 1.0*(s / h). The positional deviation factor K for the nth sub-region. posn Both are composed of the X and Y directions, with each contributing 50% of the influence, therefore K posn =50%*k XPosn +50%*k YPosn .

[0031] Multiplying the local efficiency factor by the location deviation factor yields the final efficiency deviation coefficient of the local location, which is the efficiency deviation coefficient k of the nth sub-region. Deltan =K n 2 *K posn Where n is the sub-region number, K n K is the local efficiency factor of the nth sub-region. posn This is the positional deviation factor for the nth sub-region.

[0032] 3) Sort the efficiency deviation coefficients of each sub-region in ascending order to obtain the efficiency deviation coefficient sequence {k}. Delta1 ,k Delta2 ,k Delta3 ,…,k Deltap}°

[0033] 4) Select the sub-regions corresponding to the first q efficiency deviation coefficients in the efficiency deviation coefficient sequence as the selected local regions, where q is an integer greater than or equal to 1, and q < p. In this embodiment, q = 10, that is, select the 10 sub-regions with the smallest efficiency deviation coefficients as the selected local regions. After selecting q sub-regions, number them.

[0034] 2. Filtration efficiency calculation equation

[0035] For the ultra-high efficiency filter model under test, a linear equation is established for calculating the filtration efficiency, containing unknown coefficients. That is, the filtration efficiency calculation equation is: Where Y represents the overall filtration efficiency of the ultra-high efficiency filter, i is the selected sub-region number, and x... i For the filtering efficiency of the selected i-th sub-region, k i This represents the coefficient corresponding to the selected i-th sub-region. In this embodiment, since 10 sub-regions are selected as the local regions, therefore...

[0036] Step 2: Conduct multiple experiments on the UHEPA filter of the model to be tested to obtain filtration efficiency data of a selected local area in the filtration plane of the UHEPA filter and the overall filtration efficiency data of the UHEPA filter in each experiment. Use the experimental data to solve for the unknown coefficients and then determine the filtration efficiency calculation equation.

[0037] Experiments were conducted on the selected local areas following the steps outlined above. Each experiment yielded a set of data, including the overall filtration efficiency of the ultra-high efficiency filter and the filtration efficiency of each selected sub-region. For example, the first experiment yielded the overall filtration efficiency Y1 of the ultra-high efficiency filter and the filtration efficiency x of each selected sub-region. 1,1 ~x 1,q The second experiment yielded the overall filtration efficiency Y2 of the ultra-high efficiency filter and the filtration efficiency x of each selected sub-region. 2,1 ~x 2,q This process continues until the m-th experiment yields the overall filtration efficiency Y of the ultra-high efficiency filter. m and the filtering efficiency x of each selected sub-region m,1 ~x m,q By solving a system of equations using data from multiple experiments, we obtain:

[0038]

[0039] Here, Y1~Y m This represents the overall filter efficiency value obtained by scanning the filter multiple times, x. i,j Then, k1 represents the local efficiency value of the j-th sub-region after the i-th measurement, where k1 ~ k q This represents the coefficients corresponding to the q sub-regions, which are currently unknown.

[0040] Since q = 10 in this embodiment, the above system of equations in this embodiment is:

[0041]

[0042] Based on the above equation for calculating filtration efficiency containing unknown coefficients, the experimental data is used to connect the equation system, and the equation system is transformed into a coefficient matrix. The coefficient matrix is ​​then transformed to obtain the step matrix, and finally the values ​​of the unknown coefficients are obtained.

[0043] Taking q=10 as an example, the details are as follows:

[0044] Transform the above system of equations into a coefficient matrix:

[0045]

[0046] Simultaneously, substitute the data obtained from each experiment, including Y1 to Y2. m and x i,j At this point, the matrix becomes one with only unknown coefficients k1 to k2. 10 Given a matrix, perform row operations on the matrix to obtain the echelon matrix, and finally obtain k1~k 10 The solution yields the equation for the overall efficiency.

[0047] Step 3: For the new ultra-high efficiency filter to be tested, the filtration efficiency of a selected local area in its filtration plane is tested, and the overall filtration efficiency of the ultra-high efficiency filter to be tested is calculated using the filtration efficiency calculation equation.

[0048] The above method establishes a predictive calculation equation based on the known filtration efficiency data of several filters. When testing the filtration efficiency of other new filters to be tested, only the values ​​at some locations need to be detected to calculate the overall filter efficiency, which greatly saves the scanning and testing time. This scheme helps to quickly test the efficiency of a large number of filters in batches.

[0049] The above method, by shortening the detection area and time and correctly and reasonably calculating the overall efficiency, is conducive to batch testing in factory production and greatly helps manufacturers improve filter quality and reduce production costs.

[0050] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for detecting the filtration efficiency of an ultra-high efficiency filter, used to detect the filtration efficiency of any type of ultra-high efficiency filter, characterized in that: The method is as follows: A filtration efficiency calculation equation containing unknown coefficients is established for the ultra-high efficiency filter of the model to be tested. This equation characterizes the relationship between the filtration efficiency of a selected local area in the filtration plane of the ultra-high efficiency filter and the overall filtration efficiency of the ultra-high efficiency filter. Multiple experiments are conducted on the ultra-high efficiency filter of the model to be tested to obtain filtration efficiency data for the selected local area in the filtration plane and the overall filtration efficiency data of the ultra-high efficiency filter in each experiment. The unknown coefficients are solved using the experimental data to determine the filtration efficiency calculation equation. For the ultra-high efficiency filter to be tested, the filtration efficiency of the selected local area in its filtration plane is detected, and the overall filtration efficiency of the ultra-high efficiency filter to be tested is calculated using the filtration efficiency calculation equation. The method for determining the selected local region for the filtration plane of the ultra-high efficiency filter of the model to be tested is as follows: the filtration plane of the ultra-high efficiency filter of the model to be tested is divided into p sub-regions. For each sub-region, an efficiency deviation coefficient is calculated, which characterizes the deviation between the filtration efficiency of the sub-region and the overall filtration efficiency of the ultra-high efficiency filter. The efficiency deviation coefficients are sorted in ascending order to obtain an efficiency deviation coefficient sequence. The sub-regions corresponding to the first q efficiency deviation coefficients in the efficiency deviation coefficient sequence are selected as the selected local regions, where p is an integer greater than or equal to 2, q is an integer greater than or equal to 1, and q < p.

2. The method for detecting the filtration efficiency of an ultra-high efficiency filter according to claim 1, characterized in that: The efficiency deviation coefficient k of the nth sub-region Deltan =K n 2 *K posn Where n is the number of the sub-region, K n K is the local efficiency factor of the nth sub-region. posn is the positional deviation factor for the nth sub-region.

3. The method for detecting the filtration efficiency of an ultra-high efficiency filter according to claim 2, characterized in that: K n =(f n -f All ) / f All f n f is the filtering efficiency value of the nth sub-region. All This represents the overall filtration efficiency value of the ultra-high efficiency filter.

4. The method for detecting the filtration efficiency of an ultra-high efficiency filter according to claim 2, characterized in that: K posn =50%*k XPosn +50%*k YPosn k XPosn k represents the magnitude of the deviation in the X direction of the nth sub-region relative to the center of the filtration plane of the ultra-high efficiency filter. YPosn The magnitude of the deviation of the nth sub-region from the center of the filtration plane of the ultra-high efficiency filter in the Y direction.

5. The method for detecting the filtration efficiency of an ultra-high efficiency filter according to claim 4, characterized in that: k XPosn k YPosn The value range is 0 to 1.

6. The method for detecting the filtration efficiency of an ultra-high efficiency filter according to claim 5, characterized in that: Based on the magnitude of the deviation in the X and Y directions between the center of the nth sub-region and the center or edge of the ultra-high efficiency filter's filtration plane, k is interpolated. XPosn k YPosn .

7. The method for detecting the filtration efficiency of an ultra-high efficiency filter according to claim 6, characterized in that: Let there be g sub-regions from the edge to the center in the X direction of the filter plane of the ultra-high efficiency filter, and let the nth sub-region be the rth sub-region from the edge to the center in the X direction of the filter plane of the ultra-high efficiency filter. Then k XPosn =1.0*(r / g); Let there be h sub-regions from the edge to the center in the Y direction of the filter plane of the ultra-high efficiency filter, and the nth sub-region is the s-th sub-region from the edge to the center in the Y direction of the filter plane of the ultra-high efficiency filter, then k YPosn =1.0*(s / h).

8. The method for detecting the filtration efficiency of an ultra-high efficiency filter according to claim 1, characterized in that: The equation for calculating the filtration efficiency is: Where Y is the overall filtration efficiency of the ultra-high efficiency filter, i is the selected sub-region number, and x i For the filtering efficiency of the selected i-th sub-region, k i is the coefficient corresponding to the selected i-th sub-region.

9. The method for detecting the filtration efficiency of an ultra-high efficiency filter according to claim 1, characterized in that: The ultra-high efficiency filter is divided into p sub-regions, which are arranged in an array of multiple rows and columns.

10. The method for detecting the filtration efficiency of an ultra-high efficiency filter according to claim 1, characterized in that: Based on the filtration efficiency calculation equation containing unknown coefficients, the experimental data is used to connect the equation system, and the equation system is transformed into a coefficient matrix. The coefficient matrix is ​​then transformed to obtain the step matrix, and finally the value of the unknown coefficient is obtained.

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