Cationic polyacrylamide purity detection method

Abstract

The invention discloses a cationic polyacrylamide purity detection method, and belongs to the technical field of cationic polyacrylamide purity detection, and the method specifically comprises the following steps: 1, pretreatment: installing a CPAM reagent tube and liquid collection equipment, and collecting liquid through the liquid collection equipment, the collected liquid enters a CPAM reagent tube after being subjected to filtration, re-filtration and mixing pretreatment operation, then a CPAM sample solution is transferred and dissolved in a solvent to dilute the sample solution, and the dilution concentration is within the linear range of a detection instrument; 2, HPLC separation: injecting the prepared sample into an HPLC system, selecting a special chromatographic column with a cation exchange function as a chromatographic column, and setting the flow rate, composition and temperature of a mobile phase to ensure that polyacrylamide components with different molecular weights in the sample can be completely separated. According to the scheme, through the combination of HPLC and LSC, the detection speed is remarkably increased, one-time detection can be completed within several minutes, and complex steps of a traditional method are not needed any more.

Description

Technical Field

[0001] The present invention relates to the technical field of cationic polyacrylamide purity detection, and more particularly to a method for cationic polyacrylamide purity detection. Background Art

[0002] Cationic polyacrylamide (CPAM) is a linear polymer compound with a variety of active groups that can form hydrogen bonds with many substances through affinity and adsorption. It is primarily used to flocculate negatively charged colloids and has functions such as turbidity removal, decolorization, adsorption, and adhesion. Due to its unique properties, cationic polyacrylamide plays a vital role in oilfield production, improving oil recovery efficiency, optimizing drilling fluid performance, reducing environmental pollution, and, to a certain extent, extending the life of oil wells. The rational use of CPAM can significantly improve the economic benefits and environmental protection level of oilfield production.

[0003] In the oilfield production process, CPAM is often used to improve oil recovery, especially in polymer flooding technology, where it can help increase the fluidity of crude oil, thereby increasing oil well production. If the purity of CPAM is insufficient, its flocculation properties may decline, affecting oil recovery efficiency and thus reducing crude oil production. The cost of CPAM is relatively high, especially high-purity products. Ensuring that the CPAM used has the expected purity can avoid unnecessary waste. Rapid detection of the purity of cationic polyacrylamide in the oilfield can timely adjust the addition amount or change suppliers to control costs. It is also helpful to quickly determine whether the formula needs to be adjusted to adapt to the specific conditions on site, which is crucial to ensuring the efficiency, economy, safety and environmental protection of the process. In addition, since oilfield operations are often carried out in remote areas, rapid detection can reduce the time waiting for laboratory analysis results, allowing decisions to be made faster. Summary of the Invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for detecting the purity of cationic polyacrylamide, which can realize rapid detection of the purity of CPAM in oil fields.

[0005] To solve the above problems, the present invention adopts the following technical solutions.

[0006] A method for detecting the purity of cationic polyacrylamide comprises the following steps:

[0007] Step 1: Pretreatment: Install the CPAM reagent tube and the liquid collection device, collect the liquid through the liquid collection device, filter, refilter, and mix the collected liquid before entering the CPAM reagent tube. Then, transfer the CPAM sample solution to a solvent to dilute the sample solution to a concentration within the linear range of the detection instrument.

[0008] Step 2: HPLC separation: Inject the prepared sample into the HPLC system. Select a dedicated chromatographic column with cation exchange function and set the flow rate, composition and temperature of the mobile phase to ensure that the polyacrylamide components with different molecular weights in the sample can be completely separated.

[0009] Step 3: Light scattering detection: The components separated by HPLC are detected in real time by a light scattering detector, and the purity data is obtained by combining the concentration calculation. The calculation process: The light scattering detection signal of component i separated by HPLC is Si, and its concentration is obtained after correction as C i , the purity of polyacrylamide can be expressed as:

[0010]

[0011] Wherein, n is the number of cationic polyacrylamide-related components, and m is the number of all detected components;

[0012] It represents the total concentration of all components related to cationic polyacrylamide;

[0013] It represents the sum of the concentrations of all components detected in the sample, including cationic polyacrylamide and other impurities;

[0014] Step 4: Data analysis: quantitatively calculate the content of each component through the peak area of ​​the chromatogram and the light scattering detection signal. After all the data are sorted, a purity test report is automatically generated, showing the content of cationic polyacrylamide in the sample and its molecular weight distribution information;

[0015] Preferably, in the light scattering detection step, PCA principal component analysis, linear discriminant analysis, independent component analysis and kernel principal component analysis methods are used to extract key features in the light scattering data;

[0016] Preferably, in the light scattering detection step, a feedback loop is used to monitor and adjust the power of the light source in real time to achieve light source power control and enhance light source stability. A thermostat is used to accurately control the temperature of the sample flow system to avoid changes in sample viscosity and refractive index caused by temperature changes, maintain constant temperature of the sample solution, and further adjust the flow rate according to the characteristics of the sample.

[0017] Preferably, in the light scattering detection step, the specific steps of PCA principal component analysis are as follows:

[0018] Step 1: Data standardization: standardize each feature in the data set to have a mean of 0 and a variance of 1, ensuring that all features are on the same scale.

[0019]

[0020] Where X is the original data, μ is the mean, and σ is the standard deviation;

[0021] Step 2: Calculate the covariance matrix. Calculate the covariance matrix of the standardized data set to reflect the linear relationship between features.

[0022]

[0023] Step 3: Eigenvalue decomposition, perform eigenvalue decomposition on the covariance matrix to obtain eigenvalues ​​and eigenvectors.

[0024] Cw=λw

[0025] Among them, λ is the eigenvalue and w is the eigenvector;

[0026] Step 4: Select the principal components. Select the first few eigenvectors as principal components based on the size of the eigenvalues, and retain the principal components whose cumulative variance contribution rate reaches 90%;

[0027] Step 5: Project to the principal component space. Project the original data to the principal component space to obtain the data after dimensionality reduction.

[0028] Y=X std W

[0029] Among them, W is the matrix composed of the selected principal components, and Y is the data after dimensionality reduction.

[0030] It can effectively reduce the dimension of data while retaining most of the information in the data, simplify calculations, and reduce the complexity of the model. It is suitable for data analysis and modeling.

[0031] Preferably, in the light scattering detection step, the specific steps of linear discriminant analysis are as follows:

[0032] Step 1: Calculate the intra-class scatter matrix. For each category of samples, calculate the intra-class scatter matrix.

[0033]

[0034] Among them, S i is the scatter matrix of the ith class, and μ is the mean of the ith class.

[0035] Step 2: Calculate the inter-class scatter matrix and the scatter matrix between the class means.

[0036]

[0037] Among them, N i is the number of samples in class i, and μ is the population mean.

[0038] Step 3: Eigenvalue decomposition, by solving the generalized eigenvalue problem, the between-class scatter matrix and the within-class scatter matrix are combined to obtain the projection direction.

[0039]

[0040] Step 4: Select eigenvectors. Select several eigenvectors with the largest eigenvalues ​​as projection directions and project the original data onto these directions.

[0041] It is suitable for classification problems and can effectively enhance the separation between different categories. It can retain category information while reducing the dimension and improve the performance of the classifier.

[0042] Preferably, in the light scattering detection step, the specific steps of independent component analysis are as follows:

[0043] Step 1: Centering and whitening: Centralize the data to make its mean 0, and perform whitening so that the data has the same variance.

[0044] X whiten =VΛ -1 / 2 V T X

[0045] Where V and Λ are the eigenvector matrix and eigenvalue matrix of the covariance matrix, respectively.

[0046] Step 2: Maximize non-Gaussianity. Through an iterative algorithm (such as fast ICA), find the direction that maximizes non-Gaussianity and extract independent components.

[0047] w=argmax w {negentropy(w T X)}

[0048] Here, w is the direction of the independent component.

[0049] Step 3: Extract independent components and use the obtained independent component directions to project the data onto these directions to obtain independent components.

[0050] S=W T X

[0051] Among them, S is the extracted independent component matrix.

[0052] It can effectively separate independent signals from each other, is suitable for blind source separation and signal processing, can extract potential independent features, and enhance the explanatory power of the model.

[0053] Preferably, in the light scattering detection step, the specific steps of nuclear principal component analysis are as follows:

[0054] Step 1: Select a kernel function, such as Gaussian kernel or polynomial kernel function, to map the data into a high-dimensional space.

[0055] K(x i ,x j )=φ(x i ) T φ(x j )

[0056] Step 2: Calculate the kernel matrix, calculate the kernel matrix of the data in high-dimensional space.

[0057] K=φ(X) T φ(X)

[0058] Step 3: Center the kernel matrix. The kernel matrix is ​​centralized to make it suitable for PCA.

[0059] K centered =K-1K-K1+1K1

[0060] Among them, 1 is an all-1 matrix.

[0061] Step 4: Eigenvalue decomposition: perform eigenvalue decomposition on the centralized kernel matrix and select the principal components corresponding to the first few eigenvectors.

[0062] α=K·λ

[0063] Step 5: Project to kernel space. Project the data onto the selected principal components of the kernel space to obtain the data after dimensionality reduction.

[0064] It is suitable for nonlinear feature extraction, can capture nonlinear relationships in data, perform PCA in high-dimensional space, and can handle complex data structures.

[0065] Preferably, in step 4, the eigenvalue decomposition of the centralized kernel matrix is ​​performed by non-negative matrix decomposition, and the non-negative matrix decomposition specifically includes:

[0066] Step 1: Initial matrix decomposition, assuming that the original data matrix X can be expressed as the product of two non-negative matrices W and H.

[0067] X≈WH

[0068] Step 2: Iterative optimization, use the multiplication update rule to continuously iteratively optimize the matrices W and H until convergence.

[0069]

[0070]

[0071] Step 3: Obtain low-dimensional feature representation, where the matrix W represents the feature matrix and the matrix H represents the weight of the sample on these features.

[0072] Applicable to scenarios containing only non-negative data, such as image processing and text analysis, and can extract sparse features with actual physical meaning

[0073] Preferably, the liquid collection device includes a housing, a handle is fixedly mounted on the rear end of the outer surface of the housing, and a slide rail is fixedly mounted on the front end of the outer surface of the housing, characterized in that: a sleeve is provided on the front side of the slide rail, a fixing member is fixedly mounted between the sleeve and the housing, an extension tube is connected to the front end of the sleeve, a filter head is connected to one end of the extension tube, and a turbidity meter is fixedly mounted on the outer surface of the housing;

[0074] The filter mechanism is installed inside the sleeve to perform preliminary suction and filtration on the oilfield wastewater, filter out the larger impurities in the oilfield, and discharge them out of the equipment to prevent impurities from entering the equipment and affecting subsequent detection, and at the same time prevent impurities from damaging the equipment;

[0075] The re-filtration mechanism is arranged inside the filtering mechanism to filter the oilfield wastewater again after filtering by the filtering mechanism, and further filter out the crude oil, salt, minerals and other impurities in the oilfield wastewater to prevent these substances from affecting the test results;

[0076] The mixing mechanism mixes CPAM with filtered oilfield fluid and stirs it. After stirring, the mixture is allowed to stand for a period of time to allow the formed flocs to settle. The turbidity of the supernatant after flocculation is then measured using a turbidimeter to observe the morphology of the flocs. The flocs formed by high-quality, high-purity CPAM should be more compact and uniform.

[0077] The fixing mechanism adopts quick installation and disassembly processing for the CPAM reagent tube, so that it can be quickly recharged for re-testing, improving its convenience.

[0078] Preferably, the filtering mechanism includes a reciprocating screw rod rotatably connected inside the slide rail, a motor is fixedly installed at the lower end of the slide rail, the output shaft of the motor extends to the inside of the slide rail and is fixedly connected to the reciprocating screw rod, the thread groove on the outer surface of the reciprocating screw rod is a bidirectional thread groove, the upper side of the outer surface of the reciprocating screw rod is spirally connected with a threaded sleeve 1, the front end of the outer surface of the threaded sleeve 1 is rotatably connected with a connecting rod 1, the lower side of the outer surface of the reciprocating screw rod is spirally connected with a threaded sleeve 2, the front end of the outer surface of the threaded sleeve 2 is rotatably connected with a connecting rod 2, a top block 1 is provided on the front side of the slide rail, and the connecting rod 1 and the connecting rod 2 are both rotatably connected to the top block 1.

[0079] A transmission pipe is fixedly installed on the front end surface of the top block 1, and a filter suction plate is slidably connected to the interior of the sleeve. The transmission pipe extends to the interior of the sleeve and is fixedly connected to the filter suction plate. The filter suction plate and the transmission pipe are communicated with each other. A filter plate is fixedly installed on the front side of the interior of the sleeve, and an output pipe 1 and an output pipe 2 are communicated on the upper side of the outer surface of the sleeve. The output pipe 1 is arranged at the front side of the filter plate, and the output pipe 2 is arranged at the rear side of the filter plate.

[0080] The re-filtration mechanism includes a slot 1 opened inside the connecting rod 1, a fixed column 1 is fixedly installed inside the slot 1, and the outer surface of the fixed column 1 is rotatably connected to the connecting rod 3, a slot 2 is opened inside the connecting rod 2, a fixed column 2 is fixedly installed inside the slot 2, and the outer surface of the fixed column 2 is rotatably connected to the connecting rod 4, a top block 2 is provided on the rear side of the top block 1, and the connecting rods 3 and 4 are both rotatably connected to the top block 2.

[0081] A piston plate is slidably connected to the interior of the transmission tube, a transmission column is fixedly installed between the piston plate and the second top block, a delivery pipe is provided between the transmission tube and the outer shell, and a one-way output valve is provided inside the delivery pipe, output pipe 1 and output pipe 2.

[0082] The mixing mechanism includes a threaded groove provided on the inner wall of the shell, and two groups of threaded rings are provided inside the shell corresponding to the threaded sleeve 1 and the threaded sleeve 2 respectively. The threaded rings are spirally connected to the threaded grooves, and an inner ring rod is fixedly installed on the inner wall of the threaded ring. The inner ring rods are arranged in multiple groups at an angle and are dispersed in a ring shape. A magnet 1 is provided inside the threaded ring, and magnets 2 that are mutually attracted are provided inside the threaded sleeve 1 and the threaded sleeve 2.

[0083] A gear 1 is provided on the upper side of the slide rail, and a gear 2 is engaged with the right side of the gear 1. The upper end of the reciprocating screw extends to the upper side of the slide rail and is fixedly connected to the gear 1. A rotating shaft is rotatably connected to the inside of the shell, and the upper end of the rotating shaft extends to the upper side of the shell and is fixedly connected to the gear 2. A plurality of stirring rods are fixedly installed on the outer surface of the rotating shaft, and a rubber plug is embedded in the lower end surface of the shell.

[0084] The fixing mechanism includes a handle 1 having an inner cavity formed therein, a transmission ring being slidably connected to the inner front side of the inner cavity, a spring being fixedly installed between the transmission ring and the inner front end surface of the inner cavity, a CPAM reagent tube being provided inside the inner cavity, a tube head being provided at the front end of the CPAM reagent tube, the tube head being inserted into the interior of the outer shell and being connected to the outer shell, a push plate being slidably connected to the interior of the CPAM reagent tube, and a handle 2 being provided on the rear side of the CPAM reagent tube, one end of the handle 2 extending to the interior of the CPAM reagent tube and being fixedly connected to the push plate.

[0085] Two groups of clips 1 are fixedly installed on the rear end face of the handle 1, and the two groups of clips 1 are symmetrically arranged and are L-shaped and rotated 90 degrees around the center line. Two groups of clips 2 are fixedly installed on the rear end face of the CPAM reagent tube corresponding to the clip 1, and the two groups of clips 2 are also symmetrically arranged and are rectangular and rotated 90 degrees around the center line. The clips 1 and 2 are clamped with each other.

[0086] Compared with the prior art, the present invention has the following beneficial effects:

[0087] (1) This solution uses a filtering mechanism to perform preliminary suction and filtration on the oilfield wastewater, filter out larger impurities in the oilfield, and discharge them from the equipment, preventing impurities from entering the equipment and affecting subsequent testing, while also preventing impurities from damaging the equipment.

[0088] (2) This solution sets up a refiltration mechanism to filter the oilfield wastewater after filtration, and further filters out crude oil, salt, minerals and other impurities in the oilfield wastewater to prevent these substances from affecting the test results;

[0089] (3) This scheme uses a mixing mechanism to mix and stir CPAM with filtered oilfield fluid. After stirring, the mixture is allowed to stand for a period of time to allow the formed flocs to settle. The turbidity value of the supernatant after flocculation is then measured using a turbidity meter (8) to observe the morphology of the flocs. The flocs formed by high-quality, high-purity CPAM should be more compact and uniform.

[0090] (4) This solution adopts a quick installation and disassembly process for the CPAM reagent tube by setting up a fixing mechanism, so that it can be quickly recharged for re-testing, thereby improving its convenience.

[0091] (5) This scheme significantly improves the detection speed by combining HPLC with LSC. A single test can be completed within a few minutes without the complex steps of traditional methods.

[0092] (6) The light scattering detector of this scheme can accurately detect polyacrylamides of different molecular weights, thereby improving the detection accuracy of sample purity.

[0093] (7) This new method can automatically control and analyze through software, reduce manual intervention, reduce operational errors, and improve the stability of detection data BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0095] Figure 2 For the present invention Figure 1 A in the middle is an enlarged schematic diagram;

[0096] Figure 3 It is a cross-sectional view of the overall structure of the present invention;

[0097] Figure 4 For the present invention Figure 3 The enlarged schematic diagram of point B in the middle;

[0098] Figure 5 For the present invention Figure 3 The enlarged schematic diagram of point C in the middle;

[0099] Figure 6 For the present invention Figure 3 The enlarged schematic diagram of point D in the middle;

[0100] Figure 7 For the present invention Figure 3 The enlarged schematic diagram at E in the middle;

[0101] Figure 8 For the present invention Figure 3 The enlarged schematic diagram at F in the middle;

[0102] Figure 9 For the present invention Figure 3 Enlarged schematic diagram at point G in the middle.

[0103] Description of the numbers in the figure:

[0104] 1. Housing; 2. Handle 1; 3. Slide rail; 4. Sleeve; 5. Fixing piece; 6. Extension tube; 7. Filter head; 8. Turbidimeter; 9. Motor; 10. Reciprocating screw; 11. Threaded sleeve 1; 12. Connecting rod 1; 13. Threaded sleeve 2; 14. Connecting rod 2; 15. Ejector block 1; 16. Transmission tube; 17. Filter plate; 18. Filter plate; 19. Output tube 1; 20. Output tube 2; 21. Notch 1; 22. Fixing column 1; 23. Connecting rod 3; 24. Notch 2 25. Fixed column 2; 26. Connecting rod 4; 27. Top block 2; 28. Piston plate; 29. ​​Drive shaft; 30. Delivery pipe; 31. Threaded groove; 32. Threaded ring; 33. Inner ring rod; 34. Gear 1; 35. Gear 2; 36. Rotating shaft; 37. Stirring rod; 38. Rubber stopper; 39. Inner cavity; 40. Drive ring; 41. Spring; 42. CPAM reagent tube; 43. Tube head; 44. Clamp 1; 45. Clamp 2; 46. Push plate; 47. Handle 2. DETAILED DESCRIPTION

[0105] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0106] See also Figures 1 to 9 , a method for detecting the purity of cationic polyacrylamide, comprising.

[0107] A method for detecting the purity of cationic polyacrylamide comprises the following steps:

[0108] Step 1: Pretreatment: Install the CPAM reagent tube and the liquid collection device, collect the liquid through the liquid collection device, filter, refilter, and mix the collected liquid before entering the CPAM reagent tube. Then, transfer the CPAM sample solution to a solvent to dilute the sample solution to a concentration within the linear range of the detection instrument.

[0109] Step 2: HPLC separation: Inject the prepared sample into the HPLC system. Select a dedicated chromatographic column with cation exchange function and set the flow rate, composition and temperature of the mobile phase to ensure that the polyacrylamide components with different molecular weights in the sample can be completely separated.

[0110] Step 3: Light scattering detection: The components separated by HPLC are detected in real time by a light scattering detector, and the purity data is obtained by combining the concentration calculation. The calculation process: The light scattering detection signal of component i separated by HPLC is Si, and its concentration is obtained after correction as C i , the purity of polyacrylamide can be expressed as:

[0111]

[0112] Wherein, n is the number of cationic polyacrylamide-related components, and m is the number of all detected components;

[0113] It represents the total concentration of all components related to cationic polyacrylamide;

[0114] It represents the sum of the concentrations of all components detected in the sample, including cationic polyacrylamide and other impurities;

[0115] Step 4: Data analysis: quantitatively calculate the content of each component through the peak area of ​​the chromatogram and the light scattering detection signal. After all the data are sorted, a purity test report is automatically generated, showing the content of cationic polyacrylamide in the sample and its molecular weight distribution information;

[0116] Specifically, in the light scattering detection step, PCA principal component analysis, linear discriminant analysis, independent component analysis, and kernel principal component analysis methods are used to extract key features in the light scattering data;

[0117] Specifically, the light scattering detection step uses a feedback loop to monitor and adjust the power of the light source in real time to achieve light source power control and enhance light source stability. A thermostat is used to accurately control the temperature of the sample flow system to avoid changes in sample viscosity and refractive index caused by temperature changes. The sample solution is kept at a constant temperature, and the flow rate is further adjusted according to the sample characteristics.

[0118] Specifically, in the light scattering detection step, the PCA principal component analysis steps are as follows:

[0119] Step 1: Data standardization: standardize each feature in the data set to have a mean of 0 and a variance of 1, ensuring that all features are on the same scale.

[0120]

[0121] Where X is the original data, μ is the mean, and σ is the standard deviation;

[0122] Step 2: Calculate the covariance matrix. Calculate the covariance matrix of the standardized data set to reflect the linear relationship between features.

[0123]

[0124] Step 3: Eigenvalue decomposition, perform eigenvalue decomposition on the covariance matrix to obtain eigenvalues ​​and eigenvectors.

[0125] Cw=λw

[0126] Among them, λ is the eigenvalue and w is the eigenvector;

[0127] Step 4: Select the principal components. Select the first few eigenvectors as principal components based on the size of the eigenvalues, and retain the principal components whose cumulative variance contribution rate reaches 90%;

[0128] Step 5: Project to the principal component space. Project the original data to the principal component space to obtain the data after dimensionality reduction.

[0129] Y=X std W

[0130] Among them, W is the matrix composed of the selected principal components, and Y is the data after dimensionality reduction.

[0131] It can effectively reduce the dimension of data while retaining most of the information in the data, simplify calculations, and reduce the complexity of the model. It is suitable for data analysis and modeling.

[0132] Specifically, in the light scattering detection step, the specific steps of linear discriminant analysis are as follows:

[0133] Step 1: Calculate the intra-class scatter matrix. For each category of samples, calculate the intra-class scatter matrix.

[0134]

[0135] Among them, S i is the scatter matrix of the ith class, and μ is the mean of the ith class.

[0136] Step 2: Calculate the inter-class scatter matrix and the scatter matrix between the class means.

[0137]

[0138] Among them, N i is the number of samples in class i, and μ is the population mean.

[0139] Step 3: Eigenvalue decomposition, by solving the generalized eigenvalue problem, the between-class scatter matrix and the within-class scatter matrix are combined to obtain the projection direction.

[0140]

[0141] Step 4: Select eigenvectors. Select several eigenvectors with the largest eigenvalues ​​as projection directions and project the original data onto these directions.

[0142] It is suitable for classification problems and can effectively enhance the separation between different categories. It can retain category information while reducing the dimension and improve the performance of the classifier.

[0143] Specifically, in the light scattering detection step, the specific steps of independent component analysis are as follows:

[0144] Step 1: Centering and whitening: Centralize the data to make its mean 0, and perform whitening so that the data has the same variance.

[0145] X whiten =VΛ -1 / 2 V T X

[0146] Where V and Λ are the eigenvector matrix and eigenvalue matrix of the covariance matrix, respectively.

[0147] Step 2: Maximize non-Gaussianity. Through an iterative algorithm (such as fast ICA), find the direction that maximizes non-Gaussianity and extract independent components.

[0148] w=argmax w{negentropy(w T X)}

[0149] Here, w is the direction of the independent component.

[0150] Step 3: Extract independent components and use the obtained independent component directions to project the data onto these directions to obtain independent components.

[0151] S=W T X

[0152] Among them, S is the extracted independent component matrix.

[0153] It can effectively separate independent signals from each other, is suitable for blind source separation and signal processing, can extract potential independent features, and enhance the explanatory power of the model.

[0154] Specifically, in the light scattering detection step, the specific steps of nuclear principal component analysis are as follows:

[0155] Step 1: Select a kernel function, such as Gaussian kernel or polynomial kernel function, to map the data into a high-dimensional space.

[0156] K(x i ,x j )=φ(x i ) T φ(x j )

[0157] Step 2: Calculate the kernel matrix, calculate the kernel matrix of the data in high-dimensional space.

[0158] K=φ(X) T φ(X)

[0159] Step 3: Center the kernel matrix. The kernel matrix is ​​centralized to make it suitable for PCA.

[0160] K centered =K-1K-K1+1K1

[0161] Among them, 1 is an all-1 matrix.

[0162] Step 4: Eigenvalue decomposition: perform eigenvalue decomposition on the centralized kernel matrix and select the principal components corresponding to the first few eigenvectors.

[0163] α=K·λ

[0164] Step 5: Project to kernel space. Project the data onto the selected principal components of the kernel space to obtain the data after dimensionality reduction.

[0165] It is suitable for nonlinear feature extraction, can capture nonlinear relationships in data, perform PCA in high-dimensional space, and can handle complex data structures.

[0166] Specifically, in step 4, the eigenvalue decomposition of the centralized kernel matrix is ​​performed using non-negative matrix decomposition, and the non-negative matrix decomposition specifically includes:

[0167] Step 1: Initial matrix decomposition, assuming that the original data matrix X can be expressed as the product of two non-negative matrices W and H.

[0168] X≈WH

[0169] Step 2: Iterative optimization, use the multiplication update rule to continuously iteratively optimize the matrices W and H until convergence.

[0170]

[0171] Step 3: Obtain low-dimensional feature representation, where the matrix W represents the feature matrix and the matrix H represents the weight of the sample on these features.

[0172] Applicable to scenarios containing only non-negative data, such as image processing and text analysis, and can extract sparse features with actual physical meaning

[0173] Specifically, the liquid collection device includes a housing 1, a handle 2 is fixedly mounted on the rear end of the outer surface of the housing 1, and a slide rail 3 is fixedly mounted on the front end of the outer surface of the housing 1. The device is characterized in that: a sleeve 4 is provided on the front side of the slide rail 3, a fixing member 5 is fixedly mounted between the sleeve 4 and the housing 1, an extension tube 6 is connected to the front end of the sleeve 4, and a filter head 7 is connected to one end of the extension tube 6. A turbidity meter 8 is fixedly mounted on the outer surface of the housing 1;

[0174] The filtering mechanism is arranged inside the sleeve 4, and performs preliminary suction and filtration on the oilfield sewage, filters out the larger impurities in the oilfield, and discharges them from the equipment to prevent impurities from entering the equipment and affecting subsequent detection, and at the same time prevent impurities from damaging the equipment;

[0175] The re-filtration mechanism is arranged inside the filtering mechanism to filter the oilfield wastewater again after filtering by the filtering mechanism, and further filter out the crude oil, salt, minerals and other impurities in the oilfield wastewater to prevent these substances from affecting the test results;

[0176] The mixing mechanism mixes and stirs the CPAM with the filtered oilfield fluid. After stirring, the mixture is allowed to stand for a period of time to allow the formed flocs to settle. The turbidity of the supernatant after flocculation is then measured using a turbidimeter 8 to observe the morphology of the flocs. The flocs formed by high-quality, high-purity CPAM should be more compact and uniform.

[0177] The fixing mechanism adopts quick installation and disassembly processing for the CPAM reagent tube 42, so that it can be quickly recharged for re-testing, thereby improving its convenience.

[0178] Specifically, the filtering mechanism includes a reciprocating screw 10 rotatably connected to the inside of the slide rail 3, and a motor 9 is fixedly installed at the lower end of the slide rail 3. The output shaft of the motor 9 extends to the inside of the slide rail 3 and is fixedly connected to the reciprocating screw 10. The thread groove on the outer surface of the reciprocating screw 10 is a bidirectional thread groove. The upper side of the outer surface of the reciprocating screw 10 is spirally connected to a threaded sleeve 11, and the front end of the outer surface of the threaded sleeve 11 is rotatably connected to a connecting rod 12. The lower side of the outer surface of the reciprocating screw 10 is spirally connected to a threaded sleeve 2 13, and the front end of the outer surface of the threaded sleeve 2 13 is rotatably connected to a connecting rod 2 14. A top block 15 is provided on the front side of the slide rail 3, and the connecting rod 12 and the connecting rod 2 14 are both rotatably connected to the top block 15.

[0179] A transmission pipe 16 is fixedly installed on the front end surface of the top block 15, and a filter suction plate 17 is slidably connected to the interior of the sleeve 4. The transmission pipe 16 extends to the interior of the sleeve 4 and is fixedly connected to the filter suction plate 17. The filter suction plate 17 and the transmission pipe 16 are communicated with each other. A filter plate 18 is fixedly installed on the front side of the interior of the sleeve 4. An output pipe 19 and an output pipe 2 20 are connected on the upper side of the outer surface of the sleeve 4. The output pipe 19 is arranged on the front side of the filter plate 18, and the output pipe 2 20 is arranged on the rear side of the filter plate 18.

[0180] The re-filtration mechanism includes a slot 21 opened inside the connecting rod 12, a fixing column 22 is fixedly installed inside the slot 21, and a connecting rod 3 23 is rotatably connected to the outer surface of the fixing column 22. A slot 24 is opened inside the connecting rod 2 14, a fixing column 25 is fixedly installed inside the slot 24, and a connecting rod 4 26 is rotatably connected to the outer surface of the fixing column 2 25. A top block 27 is provided on the rear side of the top block 15, and the connecting rod 3 23 and the connecting rod 4 26 are both rotatably connected to the top block 27.

[0181] The transmission tube 16 is slidably connected to a piston plate 28 inside, a transmission column is fixedly installed between the piston plate 28 and the top block 27, a delivery tube 30 is connected between the transmission tube 16 and the outer shell 1, and one-way output valves are provided inside the delivery tube 30, the output tube 1 19 and the output tube 2 20.

[0182] The mixing mechanism includes a threaded groove 31 provided on the inner wall of the outer shell 1, and two groups of threaded rings 32 are provided inside the outer shell 1 corresponding to the threaded sleeve 11 and the threaded sleeve 2 13 respectively. The threaded ring 32 is spirally connected to the threaded groove 31, and an inner ring rod 33 is fixedly installed on the inner wall of the threaded ring 32. The inner ring rod 33 is arranged in multiple groups at an angle and is dispersed in a ring shape. A magnet 1 is provided inside the threaded ring 32, and a magnet 2 that is magnetically attracted to each other is provided inside the threaded sleeve 11 and the threaded sleeve 2 13.

[0183] A gear 1 34 is provided on the upper side of the slide rail 3, and a gear 2 35 is engaged with the right side of the gear 1 34. The upper end of the reciprocating screw 10 extends to the upper side of the slide rail 3 and is fixedly connected to the gear 1 34. The interior of the shell 1 is rotatably connected to a rotating shaft 36, and the upper end of the rotating shaft 36 extends to the upper side of the shell 1 and is fixedly connected to the gear 2 35. A plurality of stirring rods 37 are fixedly installed on the outer surface of the rotating shaft 36, and a rubber plug 38 is embedded in the lower end surface of the shell 1.

[0184] The fixing mechanism includes a handle 2 having an inner cavity 39 opened therein, a transmission ring 40 being slidably connected to the inner front side of the inner cavity 39, a spring 41 being fixedly installed between the transmission ring 40 and the inner front end surface of the inner cavity 39, a CPAM reagent tube 42 being provided inside the inner cavity 39, a tube head 43 being provided at the front end of the CPAM reagent tube 42, the tube head 43 being inserted into the interior of the outer shell 1 and being communicated with the outer shell 1, a push plate 46 being slidably connected to the interior of the CPAM reagent tube 42, a handle 2 47 being provided on the rear side of the CPAM reagent tube 42, one end of the handle 2 47 extending to the interior of the CPAM reagent tube 42 and being fixedly connected to the push plate 46.

[0185] Two groups of clamps 1 44 are fixedly installed on the rear end face of the handle 1 2. The two groups of clamps 1 44 are symmetrically arranged and are L-shaped and rotated ninety degrees around the center line. Two groups of clamps 2 45 are fixedly installed on the rear end face of the CPAM reagent tube 42 corresponding to the clamps 1 44. The two groups of clamps 2 45 are also symmetrically arranged and are rectangular and rotated ninety degrees around the center line. The clamps 1 44 and 45 are clamped with each other.

[0186] Method of using the liquid collection device: First, the CPAM reagent tube 42 needs to be fixedly installed with the device. The CPAM reagent tube 42 is inserted into the inner cavity 39 on the handle 1 2, and the nozzle is inserted into the interior of the housing 1. At the same time, the CPAM reagent tube 42 squeezes the transmission ring 40 and the spring 41. Then, the CPAM reagent tube 42 is rotated ninety degrees, so that the clamping piece 1 44 on the CPAM reagent tube 42 rotates to the inside of the clamping piece 2 45. Under the action of the spring 41, the clamping piece 1 44 and the clamping piece 2 45 are clamped and fixed to each other, thereby completing the convenient installation of the CPAM reagent tube 42.

[0187] Then, the filter head 7 of the extension tube 6 is inserted into the oilfield raw liquid, and the motor 9 is started so that the output shaft of the motor 9 drives the reciprocating screw 10 to rotate, and the threaded sleeve 11 and the threaded sleeve 2 13 connected by the spiral transmission on the outer surface of the reciprocating screw 10 will move relative to each other, and the threaded sleeve 11 carries the connecting rod 12 to move, and the threaded sleeve 2 13 carries the connecting rod 2 14 to move. The connecting rod 12 and the connecting rod 2 14 are both rotatably connected to the top block 15 on the transmission tube 16, so that the filter suction plate 17 will be displaced to the rear end inside the sleeve 4 through the transmission tube 16, thereby sucking the oilfield raw liquid into the interior of the sleeve 4. In this process, the raw liquid first passes through the filtration of the filter head 7 to filter out large impurities in the raw liquid, and then passes through the filter plate 18 to filter out small impurities in the raw liquid again;

[0188] Secondly, the displacement of connecting rod 12 will cause the displacement of connecting rod 3 23 through fixed column 1 22, and connecting rod 2 14 will cause the displacement of connecting rod 4 26 through fixed column 2 25. Connecting rod 3 23 and connecting rod 4 26 are both rotatably connected to top block 2 27, so top block 27 will drive piston plate 28 to slide inside transmission pipe 16 through transmission shaft 29, thereby sucking the raw liquid after secondary filtration treatment into the interior of transmission pipe 16 through filter suction plate 17. When the raw liquid passes through filter suction plate 17, it will undergo a third filtration treatment. The salt, crude oil and other substances that may affect the test results in the raw liquid will be filtered out. Then, the threaded sleeve 11 and the threaded sleeve 2 13 on the reciprocating screw 10 will move to the end, and then they will move in the opposite direction, becoming relative displacement. At this time, the above-mentioned transmission structure will be reversed, and the piston plate 28 inside the transmission pipe 16 will move forward, and the raw liquid will be discharged into the interior of the housing 1 through the delivery pipe 30. The raw liquid containing impurities after filtering inside the sleeve 4 will be discharged from the equipment through the output pipe 19 and the output pipe 2 20 respectively.

[0189] Before the device sucks the raw liquid, a certain amount of CPAM is injected into the interior of the housing 1 by pressing the handle 2 47. As the filtered raw liquid is discharged into the interior of the housing 1 and mixed with the CPAM, the reciprocating screw 10 rotates to drive the gear 1 34 to rotate, and the gear 1 34 is engaged with the gear 2 35 on the shaft 36. The shaft 36 rotates synchronously and carries the stirring rod 37 to rotate to mix the raw liquid and CPAM. At the same time, the relative displacement of the threaded sleeve 11 and the threaded sleeve 2 13 is driven by the magnetic attraction between the magnet 1 provided inside and the magnet 2 inside the threaded ring 32 provided in the housing 1, thereby driving the threaded ring 32 to rotate synchronously. The threaded ring 32 is displaced, and the threaded ring 32 is spirally connected to the threaded groove 31 inside the shell 1. Therefore, the threaded ring 32 rotates while displacing, and the CPAM and the stock solution are mixed and stirred through the inner ring rod 33 arranged on the inner wall, thereby improving the stirring rate and mixing quality of the CPAM and the stock solution. After the mixing is completed, the mixture is allowed to stand for a certain period of time to allow the formed flocs to settle. Then the turbidity value of the supernatant after flocculation is measured by the turbidity meter 8. The flocculation efficiency is calculated based on the turbidity value of the initial suspended matter solution and the turbidity value of the supernatant after flocculation. Curves are drawn for different CPAM concentrations and flocculation efficiencies to find the optimal flocculation conditions.

[0190] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any person skilled in the art who, within the technical scope disclosed by the present invention, makes equivalent substitutions or modifications based on the technical solutions and improved concepts of the present invention shall be covered by the scope of protection of the present invention.

Claims

1. A method for detecting the purity of cationic polyacrylamide, characterized in that: The specific steps include: Step 1: Pretreatment, installing the CPAM reagent tube and the liquid collection device, and collecting the liquid through the liquid collection device. The collected liquid enters the CPAM reagent tube after filtering, re-filtering and mixing pretreatment operations, and then the CPAM sample solution is transferred and dissolved in a solvent to dilute the sample solution, and the dilution concentration is within the linear range of the detection instrument; Step 2: HPLC separation: Inject the prepared sample into the HPLC system, select a special chromatographic column with cation exchange function, and set the flow rate, composition and temperature of the mobile phase to ensure that the polyacrylamide components with different molecular weights in the sample can be completely separated; Step 3: Light scattering detection: The light scattering detector is used to detect the components separated by HPLC in real time, and the purity data is obtained by combining the concentration calculation. The light scattering detection signal of component i separated by HPLC is Si, and its concentration is obtained by correction as C i , the purity of polyacrylamide can be expressed as: Where n is the number of cationic polyacrylamide-related components, and m is the number of all detected components; It represents the total concentration of all components related to cationic polyacrylamide; It represents the sum of the concentrations of all components detected in the sample, including cationic polyacrylamide and other impurities; Step 4: Data analysis: quantitatively calculate the content of each component through the peak area of ​​the chromatogram and the light scattering detection signal. After all the data are sorted out, a purity test report is automatically generated to display the content of cationic polyacrylamide in the sample and its molecular weight distribution information.

2. A method for detecting the purity of cationic polyacrylamide according to claim 1, characterized in that: In the light scattering detection step, PCA principal component analysis, linear discriminant analysis, independent component analysis and kernel principal component analysis methods are used to extract key features in the light scattering data.

3. A method for detecting the purity of cationic polyacrylamide according to claim 1, characterized in that: In the light scattering detection step, a feedback loop is used to monitor and adjust the power of the light source in real time to achieve light source power control and enhance light source stability. A thermostat is used to accurately control the temperature of the sample flow system to avoid changes in sample viscosity and refractive index caused by temperature changes. The sample solution is kept at a constant temperature, and the flow rate is further adjusted according to the sample characteristics.

4. A method for detecting the purity of cationic polyacrylamide according to claim 2, characterized in that: In the light scattering detection step, the specific steps of PCA principal component analysis are as follows: Step 1: Data standardization: standardize each feature in the data set to have a mean of 0 and a variance of 1, ensuring that each feature is on the same scale. Among them, X is the original data, μ is the mean, and σ is the standard deviation; Step 2: Calculate the covariance matrix. Calculate the covariance matrix of the standardized data set to reflect the linear relationship between features. Step 3: Eigenvalue decomposition, perform eigenvalue decomposition on the covariance matrix to obtain eigenvalues ​​and eigenvectors; Cw=λw Among them, λ is the eigenvalue and w is the eigenvector; Step 4: Select the principal components. Select the first few eigenvectors as the principal components according to the size of the eigenvalues, and retain the principal components whose cumulative variance contribution rate reaches 90%; Step 5: Project the original data into the principal component space to obtain the data after dimensionality reduction; Y=X std W Among them, W is the matrix composed of the selected principal components, and Y is the data after dimensionality reduction.

5. A method for detecting the purity of cationic polyacrylamide according to claim 2, characterized in that: In the light scattering detection step, the specific steps of linear discriminant analysis are as follows: Step 1: Calculate the intra-class scatter matrix. For each class of samples, calculate the intra-class scatter matrix. Among them, S i is the scatter matrix of the ith class, μ is the mean of the ith class; Step 2: Calculate the inter-class scatter matrix and the scatter matrix between the class means; Among them, N i is the number of samples in the i-th class, μ is the population mean; Step 3: Eigenvalue decomposition, by solving the generalized eigenvalue problem, the between-class scatter matrix and the within-class scatter matrix are combined to obtain the projection direction; Step 4: Select eigenvectors. Select several eigenvectors with the largest eigenvalues ​​as projection directions and project the original data onto these directions.

6. A method for detecting the purity of cationic polyacrylamide according to claim 2, characterized in that: In the light scattering detection step, the specific steps of independent component analysis are as follows: Step 1: Centering and whitening: centralize the data to make its mean 0, and perform whitening so that the data has the same variance; X whiten =VΛ -1 / 2 V T X Among them, V and Λ are the eigenvector matrix and eigenvalue matrix of the covariance matrix respectively; Step 2: Maximize non-Gaussianity. Through iterative algorithms (such as fast ICA), find the direction that maximizes non-Gaussianity and extract independent components. w=argmax w {negentropy(in T X)} Among them, w is the direction of the independent component; Step 3: Extract independent components, use the obtained independent component directions, project the data onto these directions, and obtain independent components; S=W T X Among them, S is the extracted independent component matrix.

7. A method for detecting the purity of cationic polyacrylamide according to claim 2, characterized in that: In the light scattering detection step, the specific steps of nuclear principal component analysis are as follows: Step 1: Select the kernel function, such as Gaussian kernel or polynomial kernel function, to map the data into high-dimensional space; K(x i ,x j )=φ(x i ) T φ(x j ) Step 2: Calculate the kernel matrix, calculate the kernel matrix of the data in high-dimensional space; K=φ(X) T φ(X) Step 3: Centralize the kernel matrix to make it suitable for PCA. K centered =K-1K-K1+1K1 Among them, 1 is a matrix of all 1s; Step 4: Eigenvalue decomposition: perform eigenvalue decomposition on the centralized kernel matrix and select the principal components corresponding to the first few eigenvectors; α=K·λ Step 5: Project to kernel space. Project the data onto the selected principal components of the kernel space to obtain the reduced-dimensional data.

8. A method for detecting the purity of cationic polyacrylamide according to claim 7, characterized in that: In the step 4, the eigenvalue decomposition of the centralized kernel matrix is ​​performed by non-negative matrix decomposition, and the non-negative matrix decomposition specifically includes: Step 1: Initial matrix decomposition. The original data matrix X can be expressed as the product of two non-negative matrices W and H; X≈WH Step 2: Iterative optimization, using the multiplication update rule to continuously iteratively optimize the matrices W and H until convergence; Step 3: Obtain low-dimensional feature representation, matrix W represents the feature matrix, and matrix H represents the weight of the sample on these features.

9. A method for detecting the purity of cationic polyacrylamide according to claim 1, characterized in that: The liquid collection device comprises a shell (1), a handle (2) is fixedly mounted on the rear end of the outer surface of the shell (1), a slide rail (3) is fixedly mounted on the front end of the outer surface of the shell (1), and the device is characterized in that: a sleeve (4) is arranged on the front side of the slide rail (3), a fixing member (5) is fixedly mounted between the sleeve (4) and the shell (1), an extension tube (6) is connected to the front end surface of the sleeve (4), a filter head (7) is connected to one end of the extension tube (6), and a turbidity meter (8) is fixedly mounted on the outer surface of the shell (1); The filtering mechanism is arranged inside the sleeve (4) to perform preliminary suction and filtration on the oilfield sewage, filter out the larger impurities in the oilfield, and discharge them out of the equipment, thereby preventing impurities from entering the equipment and affecting subsequent detection, and preventing impurities from damaging the equipment; The re-filtration mechanism is arranged inside the filtering mechanism, and filters the oilfield wastewater filtered by the filtering mechanism again, and further filters out the crude oil, salt, minerals and other impurities in the oilfield wastewater to prevent these substances from affecting the test results; A mixing mechanism is used to mix and stir the CPAM and the filtered oilfield raw liquid. After the stirring is completed, the mixture is allowed to stand for a period of time to allow the formed flocs to settle. A turbidity meter (8) is then used to measure the turbidity value of the supernatant after flocculation to observe the morphology of the flocs. The flocs formed by high-quality and high-purity CPAM should be more compact and uniform. The fixing mechanism adopts quick installation and disassembly processing for the CPAM reagent tube (42), so that it can be quickly recharged for re-testing, thereby improving its convenience.

10. A method for detecting the purity of cationic polyacrylamide according to claim 1, characterized in that: The liquid collection device comprises a filtering mechanism including a reciprocating screw (10) rotatably connected inside a slide rail (3), a motor (9) is fixedly installed at the lower end of the slide rail (3), an output shaft of the motor (9) extends into the interior of the slide rail (3) and is fixedly connected to the reciprocating screw (10), a thread groove on the outer surface of the reciprocating screw (10) is a bidirectional thread groove, a thread sleeve (11) is spirally connected to the upper side of the outer surface of the reciprocating screw (10), a connecting rod (12) is rotatably connected to the front end of the outer surface of the thread sleeve (11), a thread sleeve (2) is spirally connected to the lower side of the outer surface of the reciprocating screw (10), a connecting rod (14) is rotatably connected to the front end of the outer surface of the thread sleeve (2) (13), a top block (15) is arranged on the front side of the slide rail (3), and both the connecting rod (12) and the connecting rod (14) are rotatably connected to the top block (15); A transmission tube (16) is fixedly mounted on the front end surface of the top block 1 (15); a filter suction plate (17) is slidably connected to the interior of the sleeve (4); the transmission tube (16) extends into the interior of the sleeve (4) and is fixedly connected to the filter suction plate (17); the filter suction plate (17) and the transmission tube (16) are in communication with each other; a filter plate (18) is fixedly mounted on the front side of the interior of the sleeve (4); an output tube 1 (19) and an output tube 2 (20) are in communication on the upper side of the outer surface of the sleeve (4); the output tube 1 (19) is arranged on the front side of the filter plate (18), and the output tube 2 (20) is arranged on the rear side of the filter plate (18); The re-filtration mechanism comprises a notch 1 (21) provided inside the connecting rod 1 (12), a fixing column 1 (22) being fixedly installed inside the notch 1 (21), a connecting rod 3 (23) being rotatably connected to the outer surface of the fixing column 1 (22), a notch 2 (24) being provided inside the connecting rod 2 (14), a fixing column 2 (25) being fixedly installed inside the notch 2 (24), a connecting rod 4 (26) being rotatably connected to the outer surface of the fixing column 2 (25), a top block 2 (27) being provided at the rear side of the top block 1 (15), and the connecting rod 3 (23) and the connecting rod 4 (26) being rotatably connected to the top block 2 (27); The transmission tube (16) is slidably connected to a piston plate (28), a transmission column is fixedly installed between the piston plate (28) and the second top block (27), a delivery tube (30) is connected between the transmission tube (16) and the housing (1), and one-way output valves are arranged inside the delivery tube (30), the first output tube (19) and the second output tube (20); The mixing mechanism comprises a threaded groove (31) formed on the inner wall of the outer shell (1); two groups of threaded rings (32) are arranged inside the outer shell (1) corresponding to the first threaded sleeve (11) and the second threaded sleeve (13); the threaded rings (32) are connected to the threaded grooves (31) by spiral transmission; inner ring rods (33) are fixedly mounted on the inner walls of the threaded rings (32); the inner ring rods (33) are arranged in multiple groups in an inclined manner and are dispersedly arranged in an annular shape; a first magnet is arranged inside the threaded ring (32); and second magnets that attract each other are arranged inside the first threaded sleeve (11) and the second threaded sleeve (13) respectively; A gear 1 (34) is arranged on the upper side of the slide rail (3), and a gear 2 (35) is meshed on the right side of the gear 1 (34). The upper end of the reciprocating screw rod (10) extends to the upper side of the slide rail (3) and is fixedly connected to the gear 1 (34). A rotating shaft (36) is rotatably connected inside the housing (1), and the upper end of the rotating shaft (36) extends to the upper side of the housing (1) and is fixedly connected to the gear 2 (35). A plurality of stirring rods (37) are fixedly mounted on the outer surface of the rotating shaft (36), and a rubber plug (38) is embedded in the lower end surface of the housing (1); The fixing mechanism comprises a handle (2) having an inner cavity (39) formed therein, a transmission ring (40) being slidably connected to the inner front side of the inner cavity (39), a spring (41) being fixedly installed between the transmission ring (40) and the inner front end surface of the inner cavity (39), a CPAM reagent tube (42) being arranged inside the inner cavity (39), a tube head (43) being arranged at the front end of the CPAM reagent tube (42), the tube head (43) being inserted into the inner part of the outer shell (1) and being in communication with the outer shell (1), a push plate (46) being slidably connected to the inner part of the CPAM reagent tube (42), a handle (47) being arranged at the rear side of the CPAM reagent tube (42), one end of which extends into the inner part of the CPAM reagent tube (42) and being fixedly connected to the push plate (46); Two groups of clamping parts 1 (44) are fixedly installed on the rear end surface of the handle 1 (2), and the two groups of clamping parts 1 (44) are symmetrically arranged and L-shaped and rotated ninety degrees around the center line. Two groups of clamping parts 2 (45) are fixedly installed on the rear end surface of the CPAM reagent tube (42) corresponding to the clamping parts 1 (44), and the two groups of clamping parts 2 (45) are also symmetrically arranged and rectangular and rotated ninety degrees around the center line. The clamping parts 1 (44) and the clamping parts 2 (45) are mutually engaged.

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