Method for automatically measuring wet weight and distribution of pulp fibers in multi-stage manner

Abstract

The invention relates to a method for automatically measuring the wet weight and distribution of pulp fibers in a multi-stage mode, and belongs to the technical field of paper-making process reconstituted tobacco. According to the method, an automatic multi-stage pulp fiber wet weight measuring device is adopted and comprises a storage unit, a measuring unit, a weighing unit, a transmission unit and a microprocessor, the microprocessor adjusts the flow of gas sprayed by the gas nozzle through the gas flow electromagnetic valve so as to blow and disperse the low-concentration reconstituted tobacco pulp in the storage unit to ensure that the low-concentration reconstituted tobacco pulp to be detected is uniformly mixed; the uniformly dispersed low-concentration reconstituted tobacco pulp vertically falls into a multi-stage wet weight frame of the measuring unit, and fibers in different length intervals in the low-concentration reconstituted tobacco pulp are respectively intercepted on different stages of wet weight frames under the action of gravity; the weight sensors of the weighing units arranged on the different stages of wet weight frames monitor the wet weight of the fibers intercepted on the stages of wet weight frames in real time so as to accurately reflect the fiber proportion condition of the pulp in different length intervals, and the detection efficiency and accuracy can be greatly improved.

Description

Technical Field

[0001] This invention relates to an automated, multi-stage method for determining the wet weight and distribution of pulp fibers, belonging to the field of papermaking reconstituted tobacco technology. Background Technology

[0002] Reconstituted tobacco (hereinafter referred to as reconstituted tobacco) is an industrialized tobacco product made using the principles and processes of wet papermaking. It involves pulping, papermaking, coating, and drying of extracted tobacco stems, scraps, and other tobacco byproducts. Compared to natural tobacco, reconstituted tobacco has a looser tissue structure, controllable physicochemical properties, and significant tar and harm reduction functions, making it an indispensable and important component of Chinese-style cigarettes.

[0003] Pulp serves as a crucial carrier between the upstream raw materials and downstream substrate of reconstituted tobacco, and fiber wet weight is a key parameter affecting pulp quality and substrate physical properties. Currently, the reconstituted tobacco industry uses the fiber wet weight testing methods of the traditional paper industry to evaluate pulp quality. Compared to traditional paper pulp, reconstituted tobacco pulp has a more complex composition, containing tobacco fibers such as stems and leaves, as well as non-tobacco components such as wood pulp and fillers. Pulp properties vary significantly, with differences in length and shape, and the quality of raw materials is unstable. Even with the same raw materials, there are substantial differences in composition depending on the origin and year. Therefore, using a single-gauge umbrella frame with varying density to evaluate pulp quality and composition cannot comprehensively and accurately reflect the pulp's composition and distribution. Furthermore, during the process of measuring the wet weight of fibers using an umbrella frame, the feeding speed and the length of the settling time make it difficult to ensure uniform mixing of the pulp. In addition, some water droplets attached to the umbrella frame inevitably remain and drip during the measurement process, resulting in large fluctuations in the wet weight data. For pulp with shorter fibers, the allowable range of wet weight fluctuations has exceeded the measured value.

[0004] Patent application No. 201720620441.0 improves the spacing of the umbrella frame in the existing Schubert freeness tester by increasing the number of inner frame sections (ribs) from the current standard of 25 to 28, and the center distance between ribs from 5 mm to 4.46 mm, thereby improving the accuracy and resolution of reconstituted tobacco pulp fiber wet weight determination by more than 20%. Patent application No. 202310899214.6 uses standard meshes of different mesh sizes combined with metal strips to prepare a reconstituted tobacco pulp mesh wet weight detection frame that can effectively trap irregularly shaped, non-fibrous tobacco pulp. The trapping mesh is one of the following standard sieves: 8 mesh, 10 mesh, 12 mesh, 14 mesh, 16 mesh, 18 mesh, 20 mesh, 24 mesh, and 30 mesh. Patent application No. 201820113107.0 relates to a pulp wet weight testing device. The pulp tank has a mesh frame with grooves inside. These grooves act as a flow guide and buffer, reducing the flocculation effect of the pulp during feeding and improving the stability and accuracy of the test results. Patent application No. CN202121860289.6 discloses a lifting device for reconstituted tobacco pulp wet weight testing equipment, including a lifting rod, a turntable, a limiting shell, and a control handle. This lifting device has good positioning stability, effectively prevents reverse rotation, can achieve multi-level adjustment, and has good docking performance.

[0005] The aforementioned devices and methods for detecting the wet weight of reconstituted tobacco pulp fibers mainly rely on manual sampling and testing. Furthermore, they can only measure the wet weight of the first level of pulp fibers at a time, failing to comprehensively reflect the proportion and composition of different pulp zones. They also cannot avoid the problem of significant fluctuations in wet weight data caused by variations in the duration of the umbrella-shaped frame's settling time and differences in human operation, leading to water droplet retention and dripping. Therefore, it is particularly important to invent an automated device and method for multi-level determination of pulp fiber wet weight and distribution, which can reflect the pulp composition across multiple zones while ensuring stable and accurate measurement results. Summary of the Invention

[0006] To address the shortcomings of existing methods for monitoring the wet weight of reconstituted tobacco pulp fibers, which rely on manual sampling and testing and can only measure the wet weight of one level of pulp fibers at a time, failing to comprehensively reflect the proportion and composition of different pulp ranges, and also unable to avoid significant fluctuations in wet weight data due to variations in the duration of the umbrella-shaped frame settling time and human operational differences causing water droplets to remain and fall, this invention proposes an automated multi-stage method for determining the wet weight and distribution of pulp fibers. This invention employs an automated multi-stage wet weight measurement device for pulp fibers, which includes a storage unit, a measurement unit, a weighing unit, a transmission unit, and a microprocessor. The microprocessor utilizes gas... A flow solenoid valve regulates the gas flow rate from the gas nozzle to disperse the low-concentration reconstituted tobacco slurry in the storage unit, ensuring uniform mixing. The uniformly dispersed low-concentration reconstituted tobacco slurry falls vertically onto the multi-stage wet weighing frame of the measuring unit. Under gravity, fibers of different length ranges in the low-concentration reconstituted tobacco slurry are trapped on different levels of the wet weighing frame. Weight sensors of the weighing units arranged on different levels of the wet weighing frame monitor the wet weight of the fibers trapped on that level of the wet weighing frame in real time to accurately reflect the fiber ratio of the slurry in different length ranges, which can significantly improve detection efficiency and accuracy.

[0007] An automated multi-stage method for determining the wet weight and distribution of pulp fibers employs an automated multi-stage pulp fiber wet weight determination device. The device includes a storage unit 1, a measuring unit 2, a weighing unit 3, a transmission unit 4, and a microprocessor 5. The storage unit 1 includes a storage chamber 101. A horizontal slide is provided at the bottom of the inner wall of the storage chamber 101. The bottom plate of the storage chamber 101 includes a partition I and a partition II. The partition I and the partition II are slidably installed in the horizontal slide from both ends of the horizontal slide. The partition I and the partition II are spliced ​​together to form a pneumatic bubbling dispersion partition 102. Gas supply pipes are buried around the perimeter of the pneumatic bubbling dispersion partition 102. A gas flow solenoid valve and several gas nozzles are installed on the gas supply pipes. The gas nozzles are higher than the plate surface of the pneumatic bubbling dispersion partition 102. The gas flow solenoid valve is electrically connected to the microprocessor 5. The measuring unit 2 includes a multi-stage wet weighing frame 201, a water filter chamber 202, and a drainage tray 203. The multi-stage wet weighing frame 201 is located directly below the storage chamber 101. The top of the multi-stage wet weighing frame 201 extends vertically upward through the storage chamber 101. The water filter chamber 202 is located directly below the multi-stage wet weighing frame 201. The bottom of the water filter chamber 202 is a conical drainage tray 203. The weighing unit 3 includes several layers of weight sensors. The weight sensors of each layer are evenly distributed on the corresponding wet weighing frame of the multi-level wet weighing frame 201. The weight sensors are electrically connected to the microprocessor 5. The transmission unit 4 includes a reciprocating drive motor I, a reciprocating drive motor II, and a longitudinal support frame. The support frame is located on one side of the measuring unit 2. A longitudinal electric slide rail is provided on the longitudinal support frame, and a transverse sliding rod slides on the longitudinal electric slide rail. The end of the transverse support rod is fixedly connected to the top of the multi-stage wet weight frame 201 through a universal joint. The reciprocating drive motor I and the reciprocating drive motor II are fixedly mounted on the longitudinal support frame through the transverse support rod I and the transverse support rod II, respectively. The reciprocating drive motor I, the reciprocating drive motor II, the partition I, and the partition II are located on the same horizontal plane. The reciprocating drive motor I is located to the left of the partition I, and the output end of the reciprocating drive motor I is fixedly connected to the left side of the partition I. The reciprocating drive motor II is located to the right of the partition II, and the output end of the reciprocating drive motor II is fixedly connected to the right side of the partition II. The longitudinal electric slide rail, the reciprocating drive motor I, and the reciprocating drive motor II are all electrically connected to the microprocessor 5. The specific steps are as follows: S1. Microprocessor controls reciprocating drive motor I and reciprocating drive motor II to push partition I and partition II along the horizontal slide rail at the bottom of the storage chamber from both ends of the horizontal slide rail toward the middle and splice them together to form a pneumatic bubble dispersion partition; S2. Add the reconstituted tobacco low-concentration slurry into the bottom-closed storage unit. The microprocessor adjusts the gas flow rate of the gas nozzle through the gas flow solenoid valve to spray and disperse the reconstituted tobacco low-concentration slurry in the storage unit. S3. The microprocessor controls the reciprocating drive motor I and the reciprocating drive motor II to pull the partition I and the partition II along the horizontal slide rail at the bottom of the storage chamber from the middle of the horizontal slide rail to both ends to separate the partition I and the partition II; S4. The uniformly dispersed low-concentration reconstituted tobacco pulp falls vertically onto the multi-stage wet weighing frame of the measuring unit. Under the action of gravity, fibers of different length ranges in the low-concentration reconstituted tobacco pulp are trapped on different levels of the wet weighing frame. The weight sensors of the weighing units arranged on different levels of the wet weighing frame monitor the wet weight of the fibers trapped on the wet weighing frame in real time. S5. The reconstituted tobacco fiber is placed on a multi-stage wet weighing rack without any water droplets falling into the filter chamber, and the weight sensor monitors in real time that the wet weight of the fiber retained on the wet weighing rack at that stage remains unchanged. The wet weight of the fiber in different length ranges retained on the wet weighing rack at different levels is recorded, and the total wet weight and fiber content in different length ranges in the reconstituted tobacco low-concentration slurry are calculated. The microprocessor controls the longitudinal electric slide rail to drive the multi-stage wet weight frame of the measuring unit upward and separate it from the storage unit via the transverse sliding rod; S6. Collect and clean the fibers of different lengths trapped on the multi-stage wet weighing frame. The microprocessor controls the longitudinal electric slide rail to drive the multi-stage wet weighing frame of the measuring unit downward through the transverse sliding rod and pass through the storage unit to complete the return of the measuring unit.

[0008] Preferably, the sidewall of the storage chamber 101 is composed of plates A, B, C, and D, which are fixedly connected sideways. Plates A and C are arranged parallel to each other, and plates B and D are arranged parallel to each other. A horizontal groove I is formed at the bottom of the inner sidewall of plate A, and a horizontal groove II is formed at the bottom of the inner sidewall of plate C. Horizontal grooves I and II are located on the same horizontal plane to form a horizontal slide on the inner sidewall of the storage chamber 101. A limiting piece is provided at the center of both horizontal grooves I and II. The pneumatic bubble dispersion baffle 102 includes baffle I and baffle II. The four sides of baffle I are A', B', C', and D', respectively. Sides A' and C' are parallel, and side B' and D' are parallel. Side A' of baffle I slides on the storage chamber. The C' side of the partition plate 101A slides in the horizontal groove Ⅰ on the inner side wall of the storage chamber 101A plate, and the B' side of the partition plate 1 has a horizontal limiting groove. The four sides of the partition plate 2 are A” side, B” side, C” side, and D” side, with A” side parallel to C” side and B” side parallel to D” side. The A” side of the partition plate 2 slides in the horizontal groove Ⅰ on the inner side wall of the storage chamber 101A plate, and the C” side of the partition plate 2 slides in the horizontal groove Ⅱ on the inner side wall of the storage chamber 101A plate. The D” side of the partition plate 2 has a horizontal positioning protrusion. When the partition plate 1 and the partition plate 2 are spliced ​​together to form the pneumatic bubble dispersion partition plate 102, the horizontal positioning protrusion is embedded in the horizontal limiting groove. A semi-circular through groove I is vertically opened at the center of the B' side of partition I, and a semi-circular through groove II is vertically opened at the center of the D” side of partition II. When partition I and partition II are spliced ​​together to form a pneumatic bubble dispersion partition 102, the semi-circular through groove I and the semi-circular through groove II form a circular central through hole. The top of the multi-stage wet weight frame 201 passes vertically upward through the circular central through hole and extends upward to the outside of the storage unit 1, and is connected to the end of the horizontal support rod through a universal joint.

[0009] More preferably, a semi-circular sealing gasket I is fixedly provided on the inner wall of the semi-circular through groove I, and a semi-circular sealing gasket II is fixedly provided on the inner wall of the semi-circular through groove II. When the partition I and the partition II are spliced ​​together to form a pneumatic bubble dispersion partition 102, the semi-circular sealing gasket I and the semi-circular sealing gasket II form a circular central sealing ring.

[0010] Preferably, the multi-level wet load rack 201 includes a supporting vertical rod and several layers of umbrella-shaped frames, which are arranged on the supporting vertical rod, and the aperture of the umbrella-shaped frames decreases from top to bottom.

[0011] Preferably, the bottom cone tip of the drainage tray 203 is a drainage outlet, and the drainage outlet is equipped with a drainage valve.

[0012] Preferably, the spacing between the gas nozzles is 5~10mm.

[0013] The blowing angle α of the gas in the gas nozzle is the angle between the gas blowing direction and the horizontal plane; the blowing angle α is positive when the gas is blown obliquely upward and negative when the gas is blown obliquely downward.

[0014] More preferably, when the average fiber length L of the reconstituted tobacco low-concentration pulp is ≥1.5mm, the blowing angle α of the gas in the gas nozzle is -10°<α≤0°, the gas flow rate v of the gas transmission pipeline is 60L / min<v≤80L / min, and the blowing dispersion time t is 6s<t≤10s. When the average fiber length L of the reconstituted tobacco low-concentration pulp is less than 1.5 mm, the blowing angle α of the gas in the gas nozzle is -30°≤α≤-10°, the gas flow rate v in the gas pipeline is 40L / min≤v≤60L / min, and the blowing dispersion time t is 3s≤t≤6s.

[0015] The average fiber length L of reconstituted tobacco low-concentration pulp was correlated with the gas injection angle α in the gas nozzle, the gas flow rate v in the gas pipeline, and the injection dispersion time t using multiple linear regression. A dataset containing 6 observations, 3 independent variables (gas injection angle α in the gas nozzle, gas flow rate v in the gas pipeline, and injection dispersion time t) and 1 dependent variable (average fiber length L of reconstituted tobacco low-concentration pulp) was constructed based on the average fiber length L of reconstituted tobacco low-concentration pulp, the gas injection angle α in the gas nozzle, the gas flow rate v in the gas pipeline, and the injection dispersion time t), as shown in Table 1. Table 1 Dataset of Bubbling Dispersion Conditions

[0016] Establish a multiple regression model: L = β0 + β1 × α + β2 × v + β3 × t; In the formula: β0 is the intercept, and β1, β2, and β3 are the partial regression coefficients of α, v, and t, respectively; The least squares method is used to find a set of coefficients that minimizes the sum of squared residuals between the actual values ​​and the model predictions for all data points. This allows us to solve for the regression coefficients β0, β1, β2, and β3. The formula for the sum of squared residuals is: ; In the formula: RSS is the sum of squared residuals. It is the actual value of the i-th sample. It is the model prediction value for the i-th sample, α 1i v 2i t 3i These are the values ​​of the first independent variable α, the second independent variable v, and the third independent variable t for the i-th sample, respectively, where n is the number of samples. After optimization, the final regression coefficients and regression equations are obtained as shown in the formula. That is, the average fiber length L of the reconstituted tobacco low-concentration pulp, the gas injection angle α in the gas nozzle, the gas flow rate v in the gas pipeline, and the injection dispersion time t satisfy the following functional relationship: L=0.180+0.008α-0.010v+0.320t; In the formula: L is the average fiber length of the reconstituted tobacco low-concentration pulp, in mm; α is the blowing angle of the gas in the gas nozzle, in °; v is the gas flow rate in the gas pipeline, in L / min; t is the blowing and dispersion time, in s; The blowing and dispersion time t is calculated based on the average fiber length L of the reconstituted tobacco low-concentration pulp, the blowing angle α of the gas in the gas nozzle, and the gas flow rate v in the gas pipeline.

[0017] Preferably, when the average fiber length L of the reconstituted tobacco low-concentration pulp is ≥2.0mm, a two-stage strip wet weighing frame is used, with the first stage strip wet weighing frame having a gear X1 of 16~20 and the second stage strip wet weighing frame having a gear X2 of 22~26. When the average fiber length of reconstituted tobacco low-concentration pulp is 1.5mm≤L<2.0mm, a two-stage strip wet weighing frame is used. The first stage strip wet weighing frame has a gear X1 of 20~24 and the second stage strip wet weighing frame has a gear X2 of 26~28. When the average fiber length of reconstituted tobacco low-concentration pulp is 1.0mm≤L<1.5mm, a three-stage wet weighing frame is used. The first and second stages of the wet weighing frame are strip-shaped wet weighing frames, and the third stage of the wet weighing frame is a mesh-shaped wet weighing frame. The X1 of the first stage strip-shaped wet weighing frame is 26~28, the X2 of the second stage strip-shaped wet weighing frame is 30~32, and the X3 of the third stage mesh-shaped wet weighing frame is 10 mesh. When the average fiber length of reconstituted tobacco low-concentration pulp is 0.5mm≤L<1.0mm, a three-stage wet weighing frame is used. The first and second stages of the wet weighing frame are strip-shaped wet weighing frames, and the third stage of the wet weighing frame is a mesh-shaped wet weighing frame. The X1 of the first stage strip-shaped wet weighing frame is 28~32, the X2 of the second stage strip-shaped wet weighing frame is 32~36, and the X3 of the third stage mesh-shaped wet weighing frame is 20 mesh.

[0018] A dataset containing 6 observations, 3 independent variables (the position of the first-level strip wet weighing frame X1, the position of the second-level strip wet weighing frame X2, and the aperture of the third-level mesh wet weighing frame X3) and one dependent variable (the average fiber length L of the reconstituted tobacco low-concentration pulp) was constructed based on the average fiber length L of the reconstituted tobacco low-concentration pulp, the position of the first-level strip wet weighing frame X1, the position of the second-level strip wet weighing frame X2, and the aperture of the third-level mesh wet weighing frame X3) and one dependent variable (the average fiber length L of the reconstituted tobacco low-concentration pulp), as shown in Table 2. Table 2 Selection Criteria for Wet Weight Frames

[0019] Establish a multiple regression model: When the average fiber length L of reconstituted tobacco low-concentration pulp is ≥2.0 mm: L = α0 + α1 × X1 + α2 × X2; In the formula, L is the average fiber length of reconstituted tobacco low-concentration pulp, in mm; α0 is the intercept; α1 is the partial regression coefficient of the first-level strip wet weight frame grade X1; α2 is the partial regression coefficient of the second-level strip wet weight frame grade X2. The least squares method is used to find a set of coefficients that minimizes the sum of squared residuals between the actual values ​​and the model predictions of all data points. This allows for the calculation of regression coefficients α0, α1, and α2. After optimization, the final regression coefficients and regression equation are obtained. Specifically, when the average fiber length L of the reconstituted tobacco low-concentration pulp is ≥ 2.0 mm, the average fiber length L of the reconstituted tobacco low-concentration pulp, the grade X1 of the first-stage strip wet weighing frame, and the grade X2 of the second-stage strip wet weighing frame satisfy the following relationship: ; X2 = X1 + 6; In the formula, L is the average fiber length of the reconstituted tobacco low-concentration pulp, in mm; X1 is the level of the first-stage strip wet weight frame, in the unit of level; X2 is the level of the second-stage strip wet weight frame, in the unit of level. When the average fiber length of reconstituted tobacco low-concentration pulp is 1.5 mm ≤ L < 2.0 mm: ; X2 = X1 + 6; In the formula, L is the average fiber length of the reconstituted tobacco low-concentration pulp, in mm; X1 is the level of the first-stage strip wet weight frame, in the unit of level; X2 is the level of the second-stage strip wet weight frame, in the unit of level. When the average fiber length of reconstituted tobacco low-concentration pulp is 1.0 mm ≤ L < 1.5 mm: L=β0+β1×X1+β2×X2+β3×X3; In the formula, L is the average fiber length of reconstituted tobacco low-concentration pulp, in mm; β0 is the intercept; β1 is the partial regression coefficient of the first-level strip wet weight frame X1; β2 is the partial regression coefficient of the second-level strip wet weight frame X2; and β3 is the partial regression coefficient of the third-level strip wet weight frame X3. The least squares method was used to find a set of coefficients that minimized the sum of squared residuals between the actual values ​​and the model predictions of all data points. This allowed the regression coefficients β0, β1, β2, and β3 to be solved. After optimization, the final regression coefficients and regression equation were obtained. Specifically, when the average fiber length of the reconstituted tobacco low-concentration pulp is 1.0 mm ≤ L < 1.5 mm, the average fiber length L, the position X1 of the first-stage strip wet-weighting frame, the position X2 of the second-stage strip wet-weighting frame, and the aperture X3 of the third-stage mesh wet-weighting frame satisfy the following relationship: ; X2 = X1 + 4; X3 is a fixed value of 10; In the formula, L is the average fiber length of the reconstituted tobacco low-concentration pulp, in mm; X1 is the level of the first-stage strip wet weighing frame, in the unit of level; X2 is the level of the second-stage strip wet weighing frame, in the unit of level; and X3 is the aperture of the third-stage mesh wet weighing frame, in the unit of mesh.

[0020] When the average fiber length of reconstituted tobacco low-concentration pulp is 0.5mm ≤ L < 1.0mm: L=γ0+γ1×X1+γ2×X2+γ3×X3; In the formula, L is the average fiber length of the reconstituted tobacco low-concentration pulp, in mm; γ0 is the intercept; γ1 is the partial regression coefficient of the first-level strip wet weight frame X1; γ2 is the partial regression coefficient of the second-level strip wet weight frame X2; and γ3 is the partial regression coefficient of the third-level strip wet weight frame X3. The least squares method was used to find a set of coefficients that minimized the sum of squared residuals between the actual values ​​and the model predictions of all data points. This allowed the regression coefficients γ0, γ1, γ2, and γ3 to be solved. After optimization, the final regression coefficients and regression equation were obtained. Specifically, when the average fiber length of the reconstituted tobacco low-concentration pulp is 0.5mm ≤ L < 1.0mm, the average fiber length L, the position X1 of the first-stage strip wet-weighting frame, the position X2 of the second-stage strip wet-weighting frame, and the aperture X3 of the third-stage mesh wet-weighting frame satisfy the following relationship: ; X2 = X1 + 4; X3 is a fixed value of 20; In the formula, L is the average fiber length of the reconstituted tobacco low-concentration pulp, in mm; X1 is the level of the first-stage strip wet weighing frame, in the unit of level; X2 is the level of the second-stage strip wet weighing frame, in the unit of level; and X3 is the aperture of the third-stage mesh wet weighing frame, in the unit of mesh.

[0021] Based on the average fiber length L of the reconstituted tobacco low-concentration pulp, the number of stages of the multi-stage wet weighing frame and the shape of each stage of the wet weighing frame are precisely selected.

[0022] The beneficial effects of this invention are: (1) This invention reduces tedious manual operations by automatically dispersing pulp, weighing online and collecting data, shortens the time for a single measurement, and greatly improves the measurement efficiency. It can measure the wet weight of pulp fibers at multiple levels at one time, comprehensively reflecting the proportion and composition of different ranges of pulp. The traditional single index of fiber wet weight has been expanded into multi-level and quantitative fiber distribution data, providing better data support for in-depth analysis of pulp quality and pulping process optimization. (2) The automated detection of this invention avoids the fluctuation of slurry uniformity caused by inconsistent slurry addition and settling time during the measurement process, avoids the problem of water droplet retention and drop caused by the length of settling time of the wet weight frame and human operation differences, resulting in large fluctuations in wet weight data, eliminates subjective bias caused by different operating methods and visual reading errors, and makes the measurement results have extremely high accuracy, stability and repeatability. Attached Figure Description

[0023] Figure 1 A schematic diagram of an automated multi-stage device for determining the wet weight of pulp fibers. Figure 2 This is a schematic diagram of a pneumatic bubble dispersion partition structure. Figure 3 This is a schematic diagram of the weighing unit structure; Figure 4 This is a schematic diagram of the structure of different wet weight frames. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described. Invention Overview This invention relates to an automated multi-stage device for determining the wet weight of pulp fibers. The device includes a storage unit 1, a measuring unit 2, a weighing unit 3, a transmission unit 4, and a microprocessor 5. The storage unit 1 includes a storage chamber 101. A horizontal slide is provided at the bottom of the inner wall of the storage chamber 101. The bottom plate of the storage chamber 101 includes a partition I and a partition II. The partition I and the partition II are slidably installed in the horizontal slide from both ends of the horizontal slide. The partition I and the partition II are spliced ​​together to form a pneumatic bubbling dispersion partition 102. Gas supply pipes are buried around the perimeter of the pneumatic bubbling dispersion partition 102. A gas flow solenoid valve and several gas nozzles are installed on the gas supply pipes. The gas nozzles are higher than the plate surface of the pneumatic bubbling dispersion partition 102. The gas flow solenoid valve is electrically connected to the microprocessor 5. The measuring unit 2 includes a multi-stage wet weighing frame 201, a water filter chamber 202, and a drainage tray 203. The multi-stage wet weighing frame 201 is located directly below the storage chamber 101. The top of the multi-stage wet weighing frame 201 extends vertically upward through the storage chamber 101. The water filter chamber 202 is located directly below the multi-stage wet weighing frame 201. The bottom of the water filter chamber 202 is a conical drainage tray 203. The weighing unit 3 includes several layers of weight sensors. The weight sensors of each layer are evenly distributed on the corresponding wet weighing frame of the multi-level wet weighing frame 201. The weight sensors are electrically connected to the microprocessor 5. The transmission unit 4 includes a reciprocating drive motor I, a reciprocating drive motor II, and a longitudinal support frame. The support frame is located on one side of the measuring unit 2. A longitudinal electric slide rail is provided on the longitudinal support frame, and a transverse sliding rod slides on the longitudinal electric slide rail. The end of the transverse support rod is fixedly connected to the top of the multi-stage wet weight frame 201 through a universal joint. The reciprocating drive motor I and the reciprocating drive motor II are fixedly mounted on the longitudinal support frame through the transverse support rod I and the transverse support rod II, respectively. The reciprocating drive motor I, the reciprocating drive motor II, the partition I, and the partition II are located on the same horizontal plane. The reciprocating drive motor I is located to the left of the partition I, and the output end of the reciprocating drive motor I is fixedly connected to the left side of the partition I. The reciprocating drive motor II is located to the right of the partition II, and the output end of the reciprocating drive motor II is fixedly connected to the right side of the partition II. The longitudinal electric slide rail, the reciprocating drive motor I, and the reciprocating drive motor II are all electrically connected to the microprocessor 5. The sidewall of the storage chamber 101 is composed of plates A, B, C, and D, which are fixedly connected sideways. Plates A and C are arranged parallel to each other, and plates B and D are arranged parallel to each other. A horizontal groove I is formed at the bottom of the inner sidewall of plate A, and a horizontal groove II is formed at the bottom of the inner sidewall of plate C. Horizontal grooves I and II are located on the same horizontal plane to form a horizontal slide on the inner sidewall of the storage chamber 101. A limiting piece is provided at the center of both horizontal grooves I and II. The pneumatic bubble dispersion baffle 102 includes baffle I and baffle II. The four sides of baffle I are A', B', C', and D', respectively. Sides A' and C' are parallel, and side B' and D' are parallel. Side A' of baffle I slides in the storage chamber. Within the horizontal sliding groove Ⅰ of the inner wall of the 101A plate, the C' side of the partition plate Ⅰ is slidably disposed within the horizontal sliding groove Ⅱ of the inner wall of the storage chamber 101A plate. A horizontal limiting groove is provided on the side of the B' side of the partition plate Ⅰ. The four sides of the partition plate Ⅱ are A” side, B” side, C” side, and D” side, respectively. The A” side is parallel to the C” side, and the B” side is parallel to the D” side. A horizontal positioning protrusion is provided on the side of the partition plate Ⅱ. When the partition plate Ⅰ and the partition plate Ⅱ are spliced ​​together to form the pneumatic bubble dispersion partition plate 102, the horizontal positioning protrusion is embedded in the horizontal limiting groove. A semi-circular through groove I is vertically opened at the center of the B' side of partition I, and a semi-circular through groove II is vertically opened at the center of the D” side of partition II. When partition I and partition II are spliced ​​together to form a pneumatic bubble dispersion partition 102, the semi-circular through groove I and the semi-circular through groove II form a circular central through hole. The top of the multi-stage wet weight frame 201 passes vertically upward through the circular central through hole and extends upward to the outside of the storage unit 1, and is connected to the end of the horizontal support rod through a universal joint.

[0026] More preferably, a semi-circular sealing gasket I is fixedly provided on the inner wall of the semi-circular through groove I, and a semi-circular sealing gasket II is fixedly provided on the inner wall of the semi-circular through groove II. When the partition I and the partition II are spliced ​​together to form a pneumatic bubble dispersion partition 102, the semi-circular sealing gasket I and the semi-circular sealing gasket II form a circular central sealing ring.

[0027] Preferably, the multi-level wet load rack 201 includes a supporting vertical rod and several layers of umbrella-shaped frames, which are arranged on the supporting vertical rod, and the aperture of the umbrella-shaped frames decreases from top to bottom.

[0028] Preferably, the bottom cone tip of the drainage tray 203 is a drainage outlet, and the drainage outlet is equipped with a drainage valve.

[0029] Preferably, the spacing between the gas nozzles is 5~10mm.

[0030] The blowing angle α of the gas in the gas nozzle is the angle between the gas blowing direction and the horizontal plane; the blowing angle α is positive when the gas is blown obliquely upward and negative when the gas is blown obliquely downward.

[0031] More preferably, when the average fiber length L of the reconstituted tobacco low-concentration pulp is ≥1.5mm, the blowing angle α of the gas in the gas nozzle is -10°<α≤0°, the gas flow rate v of the gas transmission pipeline is 60L / min<v≤80L / min, and the blowing dispersion time t is 6s<t≤10s. When the average fiber length L of the reconstituted tobacco low-concentration pulp is less than 1.5 mm, the blowing angle α of the gas in the gas nozzle is -30°≤α≤-10°, the gas flow rate v in the gas pipeline is 40L / min≤v≤60L / min, and the blowing dispersion time t is 3s≤t≤6s.

[0032] The average fiber length L of reconstituted tobacco low-concentration pulp, the gas injection angle α in the gas nozzle, the gas flow rate v in the gas delivery pipeline, and the injection dispersion time t satisfy the following functional relationship: L = 0.180 + 0.008α - 0.010v + 0.320t The blowing and dispersion time t is calculated based on the average fiber length L of the reconstituted tobacco low-concentration pulp, the blowing angle α of the gas in the gas nozzle, and the gas flow rate v in the gas pipeline.

[0033] Preferably, when the average fiber length L of the reconstituted tobacco low-concentration pulp is ≥2.0mm, a two-stage strip wet weighing frame is used, with the first stage strip wet weighing frame having a gear X1 of 16~20 and the second stage strip wet weighing frame having a gear X2 of 22~26. When the average fiber length of reconstituted tobacco low-concentration pulp is 1.5mm≤L<2.0mm, a two-stage strip wet weighing frame is used. The first stage strip wet weighing frame has a gear X1 of 20~24 and the second stage strip wet weighing frame has a gear X2 of 26~28. When the average fiber length of reconstituted tobacco low-concentration pulp is 1.0mm≤L<1.5mm, a three-stage wet weighing frame is used. The first and second stages of the wet weighing frame are strip-shaped wet weighing frames, and the third stage of the wet weighing frame is a mesh-shaped wet weighing frame. The X1 of the first stage strip-shaped wet weighing frame is 26~28, the X2 of the second stage strip-shaped wet weighing frame is 30~32, and the X3 of the third stage mesh-shaped wet weighing frame is 10 mesh. When the average fiber length of reconstituted tobacco low-concentration pulp is 0.5mm≤L<1.0mm, a three-stage wet weighing frame is used. The first and second stages of the wet weighing frame are strip-shaped wet weighing frames, and the third stage of the wet weighing frame is a mesh-shaped wet weighing frame. The X1 of the first stage strip-shaped wet weighing frame is 28~32, the X2 of the second stage strip-shaped wet weighing frame is 32~36, and the X3 of the third stage mesh-shaped wet weighing frame is 20 mesh.

[0034] When the average fiber length L of the reconstituted tobacco low-concentration pulp is ≥ 2.0 mm, the average fiber length L of the reconstituted tobacco low-concentration pulp, the first-stage strip wet weight frame position X1, and the second-stage strip wet weight frame position X2 satisfy the following relationship: ; X2 = X1 + 6; When the average fiber length of reconstituted tobacco low-concentration pulp is 1.5mm ≤ L < 2.0mm, the average fiber length L of the reconstituted tobacco low-concentration pulp, the first-stage strip wet weight frame position X1, and the second-stage strip wet weight frame position X2 satisfy the following relationship: ; X2 = X1 + 6; When the average fiber length of reconstituted tobacco low-concentration pulp is 1.0 mm ≤ L < 1.5 mm, the average fiber length L, the position X1 of the first-stage strip wet weighing frame, the position X2 of the second-stage strip wet weighing frame, and the aperture X3 of the third-stage mesh wet weighing frame satisfy the following relationship: ; X2 = X1 + 4; X3 is a fixed value of 10; When the average fiber length of reconstituted tobacco low-concentration pulp is 0.5mm ≤ L < 1.0mm, the average fiber length L, the position X1 of the first-stage strip wet weighing frame, the position X2 of the second-stage strip wet weighing frame, and the aperture X3 of the third-stage mesh wet weighing frame satisfy the following relationship: ; X2 = X1 + 4; X3 is a fixed value of 20; Based on the average fiber length L of the reconstituted tobacco low-concentration pulp, the number of stages of the multi-stage wet weighing frame and the shape of each stage of the wet weighing frame are precisely selected.

[0035] The present invention provides an automated, multi-stage method for determining the wet weight and distribution of pulp fibers, comprising the following specific steps: S1. Microprocessor controls reciprocating drive motor I and reciprocating drive motor II to push partition I and partition II along the horizontal slide rail at the bottom of the storage chamber from both ends of the horizontal slide rail toward the middle and splice them together to form a pneumatic bubble dispersion partition; S2. Add the reconstituted tobacco low-concentration slurry into the bottom-closed storage unit. The microprocessor adjusts the gas flow rate of the gas nozzle through the gas flow solenoid valve to spray and disperse the reconstituted tobacco low-concentration slurry in the storage unit. S3. The microprocessor controls the reciprocating drive motor I and the reciprocating drive motor II to pull the partition I and the partition II along the horizontal slide rail at the bottom of the storage chamber from the middle of the horizontal slide rail to both ends to separate the partition I and the partition II; S4. The uniformly dispersed low-concentration reconstituted tobacco pulp falls vertically onto the multi-stage wet weighing frame of the measuring unit. Under the action of gravity, fibers of different length ranges in the low-concentration reconstituted tobacco pulp are trapped on different levels of the wet weighing frame. The weight sensors of the weighing units arranged on different levels of the wet weighing frame monitor the wet weight of the fibers trapped on the wet weighing frame in real time. S5. The reconstituted tobacco fiber is placed on a multi-stage wet weighing rack without any water droplets falling into the filter chamber, and the weight sensor monitors in real time that the wet weight of the fiber retained on the wet weighing rack at that stage remains unchanged. The wet weight of the fiber in different length ranges retained on the wet weighing rack at different levels is recorded, and the total wet weight and fiber content in different length ranges in the reconstituted tobacco low-concentration slurry are calculated. The microprocessor controls the longitudinal electric slide rail to drive the multi-stage wet weight frame of the measuring unit upward and separate it from the storage unit via the transverse sliding rod; S6. Collect and clean the fibers of different lengths trapped on the multi-stage wet weighing frame. The microprocessor controls the longitudinal electric slide rail to drive the multi-stage wet weighing frame of the measuring unit downward through the transverse sliding rod and pass through the storage unit to complete the return of the measuring unit.

[0036] Comparative Example 1: The composition of the reconstituted tobacco low-concentration pulp in this comparative example is: leaf pulp 38.5%, stem pulp 16.5%, softwood pulp 30%, CaCO3 15%, wherein the fiber length of the leaf pulp is 0.3mm-0.5mm, the fiber length of the stem pulp is 0.4mm-0.7mm, the fiber length of the softwood pulp is 2.0mm-2.4mm, and the calcium carbonate particle size is 1000-1500 mesh. The average fiber length L in the reconstituted tobacco low-concentration pulp of this example is 1.43mm. The wet weight of fibers was tested using a single wet weight rack with 16, 22, 25, 28, and 32 settings. The results are shown in Table 3. Table 3 Wet weight of pulp fiber under a single grade

[0037] As shown in Table 3, the wet weight of the fiber increases with the increase of the wet weight rack position. The higher the position, the more water droplets adhere to the wet weight rack, and the greater the impact of water droplets on the wet weight of the fiber.

[0038] Example 1: The reconstituted tobacco low-concentration pulp in this example is the same as that in Comparative Example 1. Therefore, the average fiber length L in the reconstituted tobacco low-concentration pulp in this example is 1.43 mm, L < 1.5 mm; therefore, the blowing angle of the gas in the gas nozzle is -30° ≤ α ≤ -10°, the gas flow rate v in the gas delivery pipeline is 40 L / min ≤ v ≤ 60 L / min, and the blowing dispersion time t is 3 ≤ t ≤ 6 s; Based on the functional relationship between the average fiber length L of reconstituted tobacco low-concentration pulp and the gas injection angle α in the gas nozzle, the gas flow rate v in the gas pipeline, and the injection dispersion time t: L=0.180+0.008α-0.010v+0.320t; The gas injection angle α in the gas nozzle is selected as 0°, the gas flow rate v in the gas pipeline is selected as 60L / min, and the injection dispersion time t is calculated to be 6.0s. Since the average fiber length L in the low-concentration slurry of reconstituted tobacco is 1.43 mm, and 1.0 mm ≤ L < 1.5 mm, a three-stage wet weighing frame is adopted. The first stage strip wet weighing frame has a spacing X1 of 26 ≤ X1 ≤ 28, the second stage strip wet weighing frame has a spacing X2 of 30 ≤ X2 ≤ 32, and the third stage mesh wet weighing frame has a mesh size X3 of 10 mesh. The average fiber length L of the reconstituted tobacco low-concentration pulp, the position X1 of the first-stage strip wet weighing frame, the position X2 of the second-stage strip wet weighing frame, and the aperture X3 of the third-stage mesh wet weighing frame satisfy the following relationship: ; X2 = X1 + 4; X3 is a fixed value of 10; According to the above formula, L=1.43, the number of gears of the first-level strip wet weight rack X1=27 and the number of gears of the second-level strip wet weight rack X2=31 can be calculated. An automated multi-stage method for determining the wet weight and distribution of pulp fibers, employing an automated multi-stage pulp fiber wet weight determination device, comprises the following steps: S1. Microprocessor controls reciprocating drive motor I and reciprocating drive motor II to push partition I and partition II along the horizontal slide rail at the bottom of the storage chamber from both ends of the horizontal slide rail toward the middle and splice them together to form a pneumatic bubble dispersion partition; S2. Add the reconstituted tobacco low-concentration slurry into the bottom-closed storage unit. The microprocessor adjusts the gas flow rate of the gas nozzle through the gas flow solenoid valve to spray and disperse the reconstituted tobacco low-concentration slurry in the storage unit. S3. The microprocessor controls the reciprocating drive motor I and the reciprocating drive motor II to pull the partition I and the partition II along the horizontal slide rail at the bottom of the storage chamber from the middle of the horizontal slide rail to both ends to separate the partition I and the partition II; S4. The uniformly dispersed low-concentration reconstituted tobacco pulp falls vertically onto the multi-stage wet weighing frame of the measuring unit. Under the action of gravity, fibers of different length ranges in the low-concentration reconstituted tobacco pulp are trapped on different levels of the wet weighing frame. The weight sensors of the weighing units arranged on different levels of the wet weighing frame monitor the wet weight of the fibers trapped on the wet weighing frame in real time. S5. The reconstituted tobacco fiber is placed on a multi-stage wet weighing rack without any water droplets falling into the filter chamber, and the weight sensor monitors in real time that the wet weight of the fiber retained on the wet weighing rack at that stage remains unchanged. The wet weight of the fiber in different length ranges retained on the wet weighing rack at different levels is recorded, and the total wet weight and fiber content in different length ranges in the reconstituted tobacco low-concentration slurry are calculated. The microprocessor controls the longitudinal electric slide rail to drive the multi-stage wet weight frame of the measuring unit upward and separate it from the storage unit via the transverse sliding rod; S6. Collect and clean the fibers of different lengths trapped on the multi-stage wet weighing frame respectively. The microprocessor controls the longitudinal electric slide rail to drive the multi-stage wet weighing frame of the measuring unit to move downward through the transverse sliding rod and pass through the storage unit to complete the return of the measuring unit. The wet weight of the pulp fibers measured by the three-stage strip wet weight frame in this embodiment is shown in Table 4. Table 4. Wet weight of pulp fibers measured by a three-stage strip wet weight rack.

[0039] As shown in Table 4, the total wet weight of pulp fibers in Sample 1 was 14.9g, with 3.4g of fiber wet weight retained by the first-stage strip wet weighing frame (22.82% of the total fiber weight), 3.8g by the second-stage strip wet weighing frame (25.50% of the total fiber weight), and 7.7g by the third-stage mesh wet weighing frame (51.68% of the total fiber weight). In Sample 2, the total wet weight of pulp fibers was 15.1g, with 3.5g of fiber wet weight retained by the first-stage strip wet weighing frame (23.18% of the total fiber weight), 3.8g by the second-stage strip wet weighing frame (25.17% of the total fiber weight), and 7.8g by the third-stage mesh wet weighing frame (51.66% of the total fiber weight). The higher the wet weight rack setting, the greater the wet weight of the fiber. The three-stage wet weight rack separates fibers of different length ranges, reducing the interference of water droplets on the wet weight quality. The standard deviation between wet weight measurement groups is smaller, and the data is more stable.

[0040] Example 2: The reconstituted tobacco low-concentration slurry in this example consists of: leaf slurry 25%, stem slurry 10%, softwood slurry 50%, and CaCO3 15%. The leaf slurry fiber length is 0.3mm-0.5mm, the stem slurry fiber length is 0.4mm-0.7mm, the softwood slurry fiber length is 2.0mm-2.4mm, and the calcium carbonate particle size is 1000-1500 mesh. The average fiber length L in this example's reconstituted tobacco low-concentration slurry is 2.21mm, and L≥1.5mm. Therefore, the gas injection angle in the gas nozzle is -10°≤α≤0°, the gas flow rate v in the gas delivery pipeline is 60L / min≤v≤80L / min, and the injection dispersion time t is 6<t≤10s. Based on the functional relationship between the average fiber length L of reconstituted tobacco low-concentration pulp and the gas injection angle α in the gas nozzle, the gas flow rate v in the gas pipeline, and the injection dispersion time t: L=0.180+0.008α-0.010v+0.320t; The blowing angle α of the gas in the gas nozzle is selected as -10°, the gas flow rate of the gas pipeline is v=80L / min, and the blowing dispersion time t is calculated to be 9s. Since the average fiber length L in the low-concentration slurry of reconstituted tobacco is 2.21 mm and L≥2.0 mm, a two-stage wet weighing frame is adopted. The first stage of the strip wet weighing frame has a gear X1 of 16≤X1≤20 and the second stage of the strip wet weighing frame has a gear X2 of 22≤X2≤26. The average fiber length L of the reconstituted tobacco low-concentration pulp, the first-stage strip wet weighing frame position X1, and the second-stage strip wet weighing frame position X2 satisfy the following relationship: ; X2 = X1 + 6; According to the above formula, L=2.21, the number of gears of the first-level strip wet weight rack X1=19 and the number of gears of the second-level strip wet weight rack X2=25 can be calculated. The method for automated multi-stage determination of wet weight and distribution of pulp fibers in this embodiment is the same as that in Embodiment 1; The wet weight of the pulp fibers measured by the two-stage strip wet weight frame in this embodiment is shown in Table 5. Table 5. Wet weight of pulp fibers measured by two-stage strip wet weight rack.

[0041] As shown in Table 5, the total wet weight of pulp fibers in Sample 1 was 5.3g, with 2.0g of fiber wet weight retained by the first-stage strip wet weighing frame, accounting for 37.74% of the total fiber weight, and 3.3g of fiber wet weight retained by the second-stage strip wet weighing frame, accounting for 62.26% of the total fiber weight. In Sample 2, the total wet weight of pulp fibers was 5.3g, with 1.9g of fiber wet weight retained by the first-stage strip wet weighing frame, accounting for 35.85% of the total fiber weight, and 3.4g of fiber wet weight retained by the second-stage strip wet weighing frame, accounting for 64.15% of the total fiber weight. The higher the wet weight rack setting, the greater the wet weight of the fiber. The two-stage wet weight rack separates fibers of different length ranges, reducing the interference of water droplets on the wet weight quality. The standard deviation between wet weight measurement groups is smaller, and the data is more stable.

[0042] Example 3: The reconstituted tobacco low-concentration slurry in this example consists of: leaf slurry 25%, stem slurry 20%, softwood slurry 40%, and CaCO3 15%. The leaf slurry fiber length is 0.3mm-0.5mm, the stem slurry fiber length is 0.4mm-0.7mm, the softwood slurry fiber length is 2.0mm-2.4mm, and the calcium carbonate particle size is 1000-1500 mesh. The average fiber length L in this example's reconstituted tobacco low-concentration slurry is 1.96mm, and L≥1.5mm. Therefore, the gas injection angle in the gas nozzle is -10°≤α≤0°, the gas flow rate v in the gas delivery pipeline is 60L / min≤v≤80L / min, and the injection dispersion time t is 6<t≤10s. Based on the functional relationship between the average fiber length L of reconstituted tobacco low-concentration pulp and the gas injection angle α in the gas nozzle, the gas flow rate v in the gas pipeline, and the injection dispersion time t: L=0.180+0.008α-0.010v+0.320t; The gas injection angle α in the gas nozzle is selected as -5°, the gas flow rate in the gas pipeline is v=70L / min, and the injection dispersion time t is calculated to be 8s. Since the average fiber length L in the low-concentration slurry of reconstituted tobacco is 1.96 mm, and 1.5 mm ≤ L < 2.0 mm, a two-stage wet weighing frame is adopted. The first stage of the strip wet weighing frame has a gear X1 of 20 ≤ X1 ≤ 24, and the second stage of the strip wet weighing frame has a gear X2 of 26 ≤ X2 ≤ 28. The average fiber length L of the reconstituted tobacco low-concentration pulp, the first-stage strip wet weighing frame position X1, and the second-stage strip wet weighing frame position X2 satisfy the following relationship: ; X2 = X1 + 6; According to the above formula, L=1.96, the number of gears of the first-level strip wet weight rack X1=24 and the number of gears of the second-level strip wet weight rack X2=28 can be calculated. The method for automated multi-stage determination of wet weight and distribution of pulp fibers in this embodiment is the same as that in Embodiment 1; The wet weight of the pulp fibers measured by the two-stage strip wet weight frame in this embodiment is shown in Table 6. Table 6. Wet weight of pulp fibers measured by two-stage strip wet weight rack.

[0043] As shown in Table 6, the total wet weight of pulp fibers in Sample 1 was 6.2g, with 2.5g of fiber wet weight retained by the first-stage strip wet weighing frame, accounting for 40.32% of the total fiber weight, and 3.7g of fiber wet weight retained by the second-stage strip wet weighing frame, accounting for 59.68% of the total fiber weight. In Sample 2, the total wet weight of pulp fibers was 6.3g, with 2.5g of fiber wet weight retained by the first-stage strip wet weighing frame, accounting for 39.68% of the total fiber weight, and 3.8g of fiber wet weight retained by the second-stage strip wet weighing frame, accounting for 60.32% of the total fiber weight. The higher the wet weight rack setting, the greater the wet weight of the fiber. The two-stage wet weight rack separates fibers of different length ranges, reducing the interference of water droplets on the wet weight quality. The standard deviation between wet weight measurement groups is smaller, and the data is more stable.

[0044] Example 4: The reconstituted tobacco low-concentration slurry in this example consists of: 50% leaf slurry, 30% stem slurry, 5% softwood slurry, and 15% CaCO3. The leaf slurry fiber length is 0.3mm-0.5mm, the stem slurry fiber length is 0.4mm-0.7mm, the softwood slurry fiber length is 2.0mm-2.4mm, and the calcium carbonate particle size is 1000-1500 mesh. The average fiber length L in this example's reconstituted tobacco low-concentration slurry is 0.67mm, where L < 1.5mm. Therefore, the gas injection angle in the gas nozzle is -30° ≤ α ≤ 30°, the gas flow rate v in the gas delivery pipeline is 40L / min ≤ v ≤ 60L / min, and the injection dispersion time t is 3 ≤ t ≤ 6s. Based on the functional relationship between the average fiber length L of reconstituted tobacco low-concentration pulp and the gas injection angle α in the gas nozzle, the gas flow rate v in the gas pipeline, and the injection dispersion time t: L=0.180+0.008α-0.010v+0.320t; The gas injection angle α in the gas nozzle is selected as -20°, the gas flow rate in the gas pipeline is v=40L / min, and the injection dispersion time t is calculated to be 3s. Since the average fiber length L in the low-concentration slurry of reconstituted tobacco is 0.67 mm, and 0.5 mm ≤ L < 1 mm, a three-stage wet weighing frame is adopted. The first stage strip wet weighing frame has a spacing X1 of 28 ≤ X1 ≤ 32, the second stage strip wet weighing frame has a spacing X2 of 32 ≤ X2 ≤ 36, and the third stage mesh wet weighing frame has a mesh size X3 of 20 mesh. The average fiber length L of the reconstituted tobacco low-concentration pulp, the position X1 of the first-stage strip wet weighing frame, the position X2 of the second-stage strip wet weighing frame, and the aperture X3 of the third-stage mesh wet weighing frame satisfy the following relationship: ; X2 = X1 + 4; X3 is a fixed value of 20; According to the above formula, L=0.67, the number of gears of the first-level strip wet weight rack X1=31 and the number of gears of the second-level strip wet weight rack X2=35 can be calculated. The method for automated multi-stage determination of wet weight and distribution of pulp fibers in this embodiment is the same as that in Embodiment 1; The wet weight of the pulp fibers measured by the three-stage strip wet weight frame in this embodiment is shown in Table 7. Table 7 Wet weight of pulp fibers measured by a three-stage strip wet weight rack

[0045] As shown in Table 7, the total wet weight of pulp fibers in Sample 1 was 18.3g. The wet weight of fibers retained by the first-stage strip wet weighing frame was 4.1g, accounting for 22.4% of the total fiber weight; the wet weight of fibers retained by the second-stage strip wet weighing frame was 4.7g, accounting for 25.68% of the total fiber weight; and the wet weight of fibers retained by the third-stage mesh wet weighing frame was 9.5g, accounting for 51.91% of the total fiber weight. In Sample 2, the total wet weight of pulp fibers was 18.3g. The wet weight of fibers retained by the first-stage strip wet weighing frame was 4.1g, accounting for 22.4% of the total fiber weight; the wet weight of fibers retained by the second-stage strip wet weighing frame was 4.6g, accounting for 25.14% of the total fiber weight; and the wet weight of fibers retained by the third-stage mesh wet weighing frame was 9.6g, accounting for 52.46% of the total fiber weight. The higher the wet weight rack setting, the greater the wet weight of the fiber. The two-stage wet weight rack separates fibers of different length ranges, reducing the interference of water droplets on the wet weight quality. The standard deviation between wet weight measurement groups is smaller, and the data is more stable.

[0046] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for automated multi-stage determination of wet weight and distribution of pulp fibers, characterized by, An automatic multi-stage measuring device for the wet weight of pulp fibers is provided, which comprises a storage unit (1), a measuring unit (2), a weighing unit (3), a transmission unit (4) and a microprocessor (5), The storage unit (1) comprises a storage chamber (101), the inner side wall bottom of the storage chamber (101) is provided with a horizontal slide, the bottom plate of the storage chamber (101) comprises a partition I and a partition II, the partition I and the partition II are respectively slid in the horizontal slide from both ends of the horizontal slide, the partition I and the partition II are integrally connected to form a pneumatic bubble dispersion partition (102), the pneumatic bubble dispersion partition (102) is embedded with a gas pipeline around the periphery, the gas pipeline is provided with a gas flow electromagnetic valve and a plurality of gas nozzles, the gas nozzles are higher than the surface of the pneumatic bubble dispersion partition (102), and the gas flow electromagnetic valve is electrically connected with the microprocessor (5); The measuring unit (2) comprises a multi-stage wet weight frame (201), a water filtering bin (202) and a drainage tray (203), the multi-stage wet weight frame (201) is arranged directly below the storage chamber (101), the top of the multi-stage wet weight frame (201) vertically penetrates the storage chamber (101), the water filtering bin (202) is arranged directly below the multi-stage wet weight frame (201), and the bottom of the water filtering bin (202) is a tapered drainage tray (203); The weighing unit (3) comprises a plurality of layers of weight sensors, the weight sensors of each layer are uniformly distributed on the corresponding stage of the multi-stage wet weight frame (201), and the weight sensors are electrically connected with the microprocessor (5); The transmission unit (4) comprises reciprocating drive motors I and II, a longitudinal support frame, the support frame is arranged on one side of the measuring unit (2), the longitudinal support frame is provided with a longitudinal electric slide rail, the longitudinal electric slide rail is slid with a horizontal sliding rod, the end of the horizontal sliding rod is fixedly connected with the top end of the multi-stage wet weight frame (201) through a universal joint, the reciprocating drive motors I and II are fixedly arranged on the longitudinal support frame through horizontal support rods I and II, the reciprocating drive motors I and II, the partition I and the partition II are located on the same horizontal plane, the reciprocating drive motor I is located to the left of the partition I, the output end of the reciprocating drive motor I is fixedly connected with the left side of the partition I, the reciprocating drive motor II is located to the right of the partition II, and the output end of the reciprocating drive motor II is fixedly connected with the right side of the partition II; the longitudinal electric slide rail, the reciprocating drive motors I and II are electrically connected with the microprocessor (5); The specific steps are as follows: S1. The microprocessor controls the reciprocating drive motors I and II to respectively push the partition I and the partition II to slide along the horizontal slide at the bottom of the storage chamber from both ends of the horizontal slide to the middle and splice to form the pneumatic bubble dispersion partition; S2. The reconstituted tobacco low-concentration pulp is added into the bottom-closed storage unit, and the microprocessor adjusts the gas flow of the gas nozzle through the gas flow electromagnetic valve to blow and disperse the reconstituted tobacco low-concentration pulp in the storage unit. S3. The microprocessor controls the reciprocating drive motor I and the reciprocating drive motor II to pull the baffle I and the baffle II to slide along the horizontal slide way at the bottom of the storage chamber from the middle to the two ends of the horizontal slide way to separate the baffle I and the baffle II; S4. The uniformly dispersed reconstituted tobacco low consistency slurry falls vertically on the multi-stage wet weight frame of the measuring unit, under the action of gravity, the fibers of different length intervals in the reconstituted tobacco low consistency slurry are intercepted on the wet weight frames of different levels, and the weight sensors of the weighing units arranged on the wet weight frames of different levels monitor the wet weight of the fibers intercepted on the wet weight frames of different levels in real time; S5. After standing, the reconstituted tobacco fibers on the multi-stage wet weight frame are dripped into the filter water bin without water drop, and the weight sensor monitors the wet weight of the fibers intercepted on the wet weight frame of the level without change in real time, the wet weight of the fibers of different length intervals intercepted on the wet weight frames of different levels is recorded, and the total wet weight of the reconstituted tobacco low consistency slurry and the fiber content of different length intervals are calculated; The microprocessor controls the longitudinal electric slide rail to drive the multi-stage wet weight frame of the measuring unit to move upward and separate from the storage unit through the transverse sliding rod; S6. The fibers of different length intervals intercepted on the multi-stage wet weight frame are collected and cleaned respectively, and the microprocessor controls the longitudinal electric slide rail to drive the multi-stage wet weight frame of the measuring unit to move downward and pass through the storage unit to complete the homing of the measuring unit.

2. The method of claim 1, wherein the method is automated. The side wall of the storage chamber (101) is composed of A plate, B plate, C plate and D plate which are sequentially fixedly connected in side, the A plate and the C plate are arranged in parallel, the B plate and the D plate are arranged in parallel, the bottom of the inner side wall of the A plate is provided with a horizontal slide groove I, the bottom of the inner side wall of the C plate is provided with a horizontal slide groove II, the horizontal slide groove I and the horizontal slide groove II are located on the same horizontal plane to form the horizontal slide way of the inner side wall of the storage chamber (101), and the centers of the horizontal slide groove I and the horizontal slide groove II are provided with limiting sheets, the pneumatic bubbling dispersion baffle (102) comprises a baffle I and a baffle II, four edges of the baffle I are A' edge, B' edge, C' edge and D' edge, the A' edge and the C' edge are parallel, the B' edge and the D' edge are parallel, the A' edge of the baffle I is slidably arranged in the horizontal slide groove I of the inner side wall of the A plate of the storage chamber (101), the C' edge of the baffle I is slidably arranged in the horizontal slide groove II of the inner side wall of the A plate of the storage chamber (101), and the B' edge of the baffle I is provided with a horizontal limiting groove on the side; four edges of the baffle II are A" edge, B" edge, C" edge and D" edge, the A" edge and the C" edge are parallel, the B" edge and the D" edge are parallel, the A" edge of the baffle II is slidably arranged in the horizontal slide groove I of the inner side wall of the A plate of the storage chamber (101), the C" edge of the baffle II is slidably arranged in the horizontal slide groove II of the inner side wall of the A plate of the storage chamber (101), the D" edge of the baffle II is provided with a horizontal positioning convex body on the side, and when the baffle I and the baffle II are integrally connected to form the pneumatic bubbling dispersion baffle (102), the horizontal positioning convex body is embedded in the horizontal limiting groove. A semicircular through slot I is vertically arranged at the center of the B' side of the partition plate I, and a semicircular through slot II is vertically arranged at the center of the D" side of the partition plate II, when the partition plate I and the partition plate II are integrated to form the pneumatic bubbling dispersion partition plate (102), the semicircular through slot I and the semicircular through slot II form a circular central through hole, and the top of the multi-stage wet weight frame (201) vertically penetrates the circular central through hole and extends upward to the outside of the storage unit (1) through the universal joint and the end of the transverse support rod.

3. The method of claim 2, wherein the method is automated. A semicircular sealing gasket I is fixedly arranged on the inner wall of the semicircular through slot I, and a semicircular sealing gasket II is fixedly arranged on the inner wall of the semicircular through slot II, when the partition plate I and the partition plate II are integrated to form the pneumatic bubbling dispersion partition plate (102), the semicircular sealing gasket I and the semicircular sealing gasket II form a circular central sealing ring.

4. The method of claim 1, wherein the method is automated. The multi-stage wet weight frame (201) comprises a support vertical rod and a plurality of layers of umbrella-shaped frames, the plurality of layers of umbrella-shaped frames are arranged on the support vertical rod, and the hole diameters of the umbrella-shaped frames gradually decrease from top to bottom.

5. The method of claim 1, wherein the method is automated. The bottom of the drainage tray (203) is tapered to form a drainage port, and the drainage port is provided with a drainage valve.

6. The method of claim 1, wherein the method is automated. The spacing of the gas nozzles is 5-10 mm.

7. The method of claim 6, wherein the method further comprises: When the average length L of the fibers of the low-concentration slurry of the reconstituted tobacco leaf is greater than or equal to 1.5 mm, the blowing angle a of the gas in the gas nozzle is -10°≤a≤0°, the gas flow rate v of the gas pipeline is 60 L / min≤v≤80 L / min, and the blowing dispersion time t is 6 s≤t≤10 s; ​ When the average length L of the fibers of the low-concentration slurry of the reconstituted tobacco leaf is less than 1.5 mm, the blowing angle a of the gas in the gas nozzle is -30°≤a≤-10°, the gas flow rate v of the gas pipeline is 40 L / min≤v≤60 L / min, and the blowing dispersion time t is 3 s≤t≤6 s.

8. The method of claim 7, wherein the method further comprises: The average length L of the fibers of the low-concentration slurry of the reconstituted tobacco leaf, the blowing angle a of the gas in the gas nozzle, the gas flow rate v of the gas pipeline, and the blowing dispersion time t satisfy the following functional relationship: L = 0.180 + 0.008a - 0.010v + 0.320t The blowing dispersion time t is calculated according to the average length L of the fibers of the low-concentration slurry of the reconstituted tobacco leaf, the blowing angle a of the gas in the gas nozzle, and the gas flow rate v of the gas pipeline.

9. The method of claim 1, wherein the method is automated. When the average length L of the fibers of the low-concentration slurry of the reconstituted tobacco leaf is greater than or equal to 2.0 mm, two-stage strip-shaped wet weight frames are used, the gear X1 of the first-stage strip-shaped wet weight frame is 16-20, and the gear X2 of the second-stage strip-shaped wet weight frame is 22-26; When the average length L of the fibers of the low-concentration slurry of the reconstituted tobacco leaf is 1.5 mm≤L<2.0 mm, two-stage strip-shaped wet weight frames are used, the gear X1 of the first-stage strip-shaped wet weight frame is 20-24, and the gear X2 of the second-stage strip-shaped wet weight frame is 26-28; When the average length L of the fibers of the low-concentration slurry of the reconstituted tobacco leaf is 1.0 mm≤L<1.5 mm, three-stage wet weight frames are used, the first-stage and second-stage wet weight frames are strip-shaped wet weight frames, the third-stage wet weight frame is a net-shaped wet weight frame, the gear X1 of the first-stage strip-shaped wet weight frame is 26-28, the gear X2 of the second-stage strip-shaped wet weight frame is 30-32, and the hole diameter X3 of the third-stage net-shaped wet weight frame is 10 meshes. When the average length of the fibers of the low consistency pulp of the reconstituted tobacco leaf is 0.5mm≤L<1.0mm, a three-stage wet screening frame is used, the first-stage and second-stage wet screening frames are strip-shaped wet screening frames, the third-stage wet screening frame is a mesh-shaped wet screening frame, the first-stage strip-shaped wet screening frame has a position X1 of 28-32, the second-stage strip-shaped wet screening frame has a position X2 of 32-36, and the third-stage mesh-shaped wet screening frame has a mesh size X3 of 20 mesh.

10. The method of claim 9, wherein the method further comprises: When the average length of the fibers of the low consistency pulp of the reconstituted tobacco leaf is L≥2.0mm, the average length of the fibers of the low consistency pulp of the reconstituted tobacco leaf L, the position X1 of the first-stage strip-shaped wet screening frame, and the position X2 of the second-stage strip-shaped wet screening frame satisfy the following relationship: ​ ； X2=X1+6; When the average length of the fibers of the low consistency pulp of the reconstituted tobacco leaf is 1.5mm≤L<2.0mm, the average length of the fibers of the low consistency pulp of the reconstituted tobacco leaf L, the position X1 of the first-stage strip-shaped wet screening frame, and the position X2 of the second-stage strip-shaped wet screening frame satisfy the following relationship: ； X2=X1+6; When the average length of the fibers of the low consistency pulp of the reconstituted tobacco leaf is 1.0mm≤L<1.5mm, the average length of the fibers of the low consistency pulp of the reconstituted tobacco leaf L, the position X1 of the first-stage strip-shaped wet screening frame, the position X2 of the second-stage strip-shaped wet screening frame, and the mesh size X3 of the third-stage mesh-shaped wet screening frame satisfy the following relationship: ； X2=X1+4; X3 is a fixed value of 10; When the average length of the fibers of the low consistency pulp of the reconstituted tobacco leaf is 0.5mm≤L<1.0mm, the average length of the fibers of the low consistency pulp of the reconstituted tobacco leaf L, the position X1 of the first-stage strip-shaped wet screening frame, the position X2 of the second-stage strip-shaped wet screening frame, and the mesh size X3 of the third-stage mesh-shaped wet screening frame satisfy the following relationship: ； X2=X1+4; X3 is a fixed value of 20; The number of stages of the multi-stage wet screening frame and the shape of each stage of the wet screening frame are accurately selected according to the average length L of the fibers of the low consistency pulp of the reconstituted tobacco leaf.

Images