Spiral mixing and bleaching apparatus for plant fibers

Abstract

The application discloses a spiral mixing and bleaching device for plant fibers, which comprises a conveying shell and a conveying and mixing screw rod, the conveying shell is provided with a feeding port and a discharging port, the conveying and mixing screw rod comprises a conveying shaft, the conveying shaft is rotationally connected with the conveying shell, the conveying shaft is provided with spiral blades and spiral grooves, the spiral blades and the spiral grooves are arranged on the inner side of the conveying shell, the spiral blades and the spiral grooves can convey materials from the feeding port to the discharging port, the spiral blades are provided with a plurality of mixing and dispersing notches, the mixing and dispersing notches are arranged at intervals along the extension direction of the spiral blades, and the mixing and dispersing notches are connected with the spiral grooves on the two sides. During rotation of the conveying and mixing screw rod, the local turbulent flow can be formed at the position of the mixing and dispersing notches, the side edges of the mixing and dispersing notches can disperse the materials, the contact and mixing of the materials and the chemical liquid are promoted, the bleaching of the fibers is more uniform, and the consumption of the chemical liquid is reduced.

Description

Technical Field

[0001] This invention relates to the field of papermaking fiber production technology, and in particular to a spiral mixing bleaching device for plant fibers. Background Technology

[0002] In the papermaking pulping process, plant fibers such as wood fiber, bamboo fiber, and reed fiber require a bleaching process, specifically by adding bleaching solutions such as hydrogen peroxide and sodium hydroxide. The bleaching effect of the fibers affects the whiteness and color uniformity of the paper. Existing technologies employ a spiral mixing structure for bleaching, where the fibers are added to a shell while bleaching solutions are added inwards from the shell. The fibers and bleaching solutions are then pushed and mixed by a spiral within the shell to achieve bleaching. However, in this spiral mixing method, the fibers tend to clump together in the spiral grooves. Once clumped, the internal fibers do not easily come into contact with the bleaching solution, resulting in uneven bleaching. A larger amount of bleaching solution is needed to improve the bleaching effect and whiteness consistency, leading to higher costs for bleaching materials and processing. Summary of the Invention

[0003] The main objective of this invention is to propose a spiral mixing bleaching device for plant fibers, which aims to solve the technical problems of insufficient uniform mixing and large amount of chemical solution added in the existing technology.

[0004] To achieve the above objectives, the present invention proposes a spiral mixing bleaching device for plant fibers, comprising a conveying housing and a conveying mixing screw. The conveying housing is provided with an inlet and an outlet. The conveying mixing screw includes a conveying shaft, which is rotatably connected to the conveying housing. The conveying shaft is provided with spiral blades and spiral grooves, which are located on the inner side of the conveying housing. The spiral blades and spiral grooves can convey materials from the inlet to the outlet. The spiral blades are provided with multiple mixing and dispersing notches, which are spaced apart along the extension direction of the spiral blades. The mixing and dispersing notches communicate with the spiral grooves located on both sides.

[0005] Material is added to the inside of the conveyor housing through the feed inlet. As the conveying and mixing screw rotates, the chemical solution is also added to the inside of the conveyor housing. The material is conveyed and stirred in the spiral groove towards the discharge port and further mixed with the chemical solution for bleaching. During the rotation of the conveying and mixing screw, the setting of the mixing and dispersing notch can create local turbulence at the mixing and dispersing notch position. The side of the mixing and dispersing notch can disperse the material, promote the contact and mixing of the material and the chemical solution, thereby making the fiber bleaching more uniform and reducing the amount of chemical solution used.

[0006] Preferably, a portion of the pitch length of the helical blade is used as a mixing section, and the mixing and dispersing notches on two adjacent mixing sections are circumferentially misaligned.

[0007] During conveying, most of the material resides in the lower part of the conveying and mixing screw, and a liquid layer exists on the inner bottom of the conveying casing, soaking the material. Each rotation of the conveying and mixing screw pushes the material clump below the screw forward by one screw pitch. In this design, the mixing and dispersing notches on adjacent mixing sections are circumferentially staggered. Therefore, during material pushing, if a material clump in the liquid layer passes through a mixing and dispersing notch without being dispersed, it will be dispersed by subsequent staggered mixing and dispersing notches when pushed forward by one or a multiple of the screw pitch. This ensures that even with a shallow liquid layer below the conveying and mixing screw, the material in the liquid layer can fully contact the liquid, improving the utilization rate of the liquid and reducing the amount of liquid added, further reducing the amount of liquid used.

[0008] Preferably, in the extending direction of the spiral blade, the interval angle β1 between two adjacent mixing and dispersing notches is 60-65°, the mixing and dispersing notches are arranged in a fan shape, and the included angle β2 between the two sides of the mixing and dispersing notches is 25-35°.

[0009] Preferably, the conveying housing is provided with an external liquid inlet, which is used to add liquid medicine to the inside of the conveying housing;

[0010] And / or, the inner side of the conveying shaft is provided with an infusion channel, the end of the conveying shaft is provided with an infusion port communicating with the infusion channel, and the conveying shaft is provided with an inner liquid inlet communicating with the infusion channel. The inner liquid inlet is used to add medicine into the spiral groove.

[0011] The liquid medicine can be added from the outer inlet on the conveyor housing (radially from the outside of the material) and / or from the inner inlet on the conveyor shaft (radially from the inside of the material) to contact and mix with the material. Both methods allow the liquid medicine to be added from the inside of the conveyor housing for mixing. When both outer and inner inlets are provided, the liquid medicine can be added from both the outer and inner radial sides of the material, increasing the contact and mixing points between the material and the liquid medicine, reducing blind spots in the mixing process, thereby improving the uniformity of the mixing and reducing the amount of liquid medicine needed.

[0012] Preferably, the spiral blades are provided with a feeding section, a dispersing and dosing section and a mixing section in the axial direction of the conveying shaft. The feeding section, the dispersing and dosing section and the mixing section are arranged sequentially in the direction from the feed inlet to the discharge outlet. The feed inlet is directly opposite the feeding section, the external liquid inlet and the internal liquid inlet are both opposite the dispersing and dosing section, and the mixing and dispersing notch is provided on the mixing section.

[0013] The material enters the feeding section through the inlet and is then conveyed to the dispersing and dosing section. The lumpy material is dispersed in the dispersing and dosing section, which increases the contact area with the liquid medicine. The liquid medicine is added in the dispersing and dosing section and comes into contact with and mixes with the dispersed material, making the mixture of liquid medicine and material more uniform. Then the material is conveyed to the mixing section, where the material and liquid medicine are further stirred and mixed to ensure that the material and liquid medicine react fully for bleaching.

[0014] Preferably, the spiral blade located in the dispersing and dosing section includes a plurality of dispersing teeth, which are arranged at intervals along the extension direction of the spiral blade, and a dispersing and material passing gap is provided between two adjacent dispersing teeth.

[0015] Because the material is compressed into clumps by the pretreatment process before bleaching, most of the material will be in clumps when it enters the feed inlet. This solution uses multiple dispersing teeth to break up the material, resulting in more even mixing with the chemical solution and ensuring that the material inside the clumps also comes into contact with the chemical solution.

[0016] Preferably, the dispersing teeth include a first plate and a second plate connected together. Both the first plate and the second plate are connected to the conveying shaft and extend radially along the conveying shaft. The first plate and the second plate are set at an obtuse angle. The connection angle between the first plate and the second plate protrudes toward the conveying direction of the spiral blade. Both the first plate and the second plate are set at an angle to the tangent direction of the spiral blade at the connection angle between the first plate and the second plate.

[0017] When the conveying screw rotates, the corner between the first and second plates impacts and breaks up clumps of material. The conical corner makes it easier to disperse the material. After dispersion, some material is pushed forward by the dispersing teeth, while others pass through the gap between the first and second plates to prevent material from remaining on the teeth. Furthermore, the first and second plates are set at an obtuse angle, and both are angled to the tangent of the screw blades. This design effectively disperses the material while pushing most of it forward, maintaining high material conveying efficiency.

[0018] Preferably, the infusion port is connected to a rotary joint.

[0019] Preferably, both the external and internal liquid inlets are equipped with atomizing nozzles, which atomize the liquid medicine before spraying it out. The liquid medicine is sprayed through the atomizing nozzles, resulting in a mist-like spray onto the material, thus increasing the contact area between the liquid medicine and the material and ensuring more uniform mixing.

[0020] Preferably, the spiral mixing bleaching device further includes a drive motor, which is fixed relative to the conveying housing and is connected to the conveying shaft for transmission. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 This is a cross-sectional view of the spiral mixing bleaching device of the present invention;

[0023] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0024] Figure 3 This is a partial structural diagram of the hybrid section of the present invention;

[0025] Figure 4 This is a side view of the mixing and dispersing notches on adjacent mixing sections facing each other in Embodiments 1 and 3 of the present invention.

[0026] Figure 5 This is a schematic diagram of the structure in Embodiments 1 and 3 of the present invention, in which the material agglomerate passes through the mixing and dispersing gap without being dispersed when it is advanced by one screw pitch.

[0027] Figure 6 This is a side view of the misaligned mixing and dispersing notches on adjacent mixing sections in Embodiments 2 and 4 of the present invention.

[0028] Figure 7 This is a schematic diagram of the structure in Embodiments 2 and 4 of the present invention, in which a material agglomerate passes through a mixing and dispersing gap without being dispersed in a mixing section;

[0029] Figure 8 This is a schematic diagram of the structure in Embodiments 2 and 4 of the present invention, in which the material agglomeration is dispersed by the misaligned mixing and dispersing notch when it is pushed to the next mixing section.

[0030] Figure 9 This is a partial structural diagram of the dispersing and dosing section of the present invention;

[0031] Figure 10(a) is a picture of the fiber after bleaching using the spiral mixing structure of the prior art, and Figure 10(b) is a picture of the fiber after bleaching using the spiral mixing bleaching device of Embodiment 4 of the present invention.

[0032] In the attached diagram: 1-Conveying shell, 11-Inlet, 12-Outlet, 13-External liquid inlet, 21-Conveying shaft, 22-Spiral blade, 221-Inlet section, 222-Dispersing and dosing section, 223-Mixing section, 23-Spiral groove, 24-Infusion channel, 241-Infusion port, 242-Internal liquid inlet, 25-Dispersing teeth, 251-First plate, 252-Second plate, 26-Dispersing material passage gap, 27-Mixing and dispersing notch, 3-Drive motor, 4-Material clump, 5-Medicine liquid layer.

[0033] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that if the embodiments of the present invention involve directional indicators, such as up, down, left, right, front, back, etc., the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0036] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0037] like Figures 1 to 9 As shown, a spiral mixing bleaching device for plant fibers includes a conveying housing 1 and a conveying mixing screw.

[0038] The conveying shell 1 is basically cylindrical and arranged horizontally. The conveying shell 1 is provided with an inlet 11 and an outlet 12. The material is added into the conveying shell 1 through the inlet 11, and the bleached material is discharged through the outlet 12.

[0039] The conveying and mixing screw includes a transversely arranged conveying shaft 21, which is rotatably connected to the conveying housing 1. The conveying shaft 21 is provided with helical blades 22 and helical grooves 23, which are located inside the conveying housing 1. The helical blades 22 and helical grooves 23 can convey materials from the inlet 11 to the outlet 12. The helical blades 22 are provided with multiple mixing and dispersing notches 27. (Refer to...) Figure 3 Multiple mixing and dispersing notches 27 are arranged at intervals along the extension direction of the spiral blades 22, and the mixing and dispersing notches 27 connect to the spiral grooves 23 located on both sides. The spiral mixing bleaching device also includes a drive motor 3, which is fixed relative to the conveying housing 1 and is connected to the conveying shaft 21. The drive motor 3 can drive the conveying mixing screw to rotate.

[0040] Material is added to the inside of the conveying housing 1 through the feed inlet 11. As the conveying and mixing screw rotates, the bleaching solution is also added to the inside of the conveying housing 1. The material is conveyed and stirred within the spiral groove 23 towards the discharge outlet 12, where it is further mixed with the bleaching solution for bleaching. During conveying, most of the material is located at the bottom of the conveying and mixing screw, and there is a bleaching solution layer 5 at the bottom of the inner side of the conveying housing 1. This bleaching solution layer 5 soaks the material, making it prone to clumping at the bottom of the conveying and mixing screw. Material inside the material clumps 4 does not easily come into contact with the bleaching solution, requiring a deeper bleaching solution layer 5 and a longer soaking time to ensure the bleaching effect. During the rotation of the conveying and mixing screw, the mixing and dispersing notch 27 creates localized turbulence at its location. The sides of the mixing and dispersing notch 27 disperse the material, promoting contact and mixing between the material and the bleaching solution, resulting in more uniform fiber bleaching and reduced bleaching solution usage.

[0041] In some specific embodiments, a portion of the pitch length of the helical blade 22 is used as a mixing section, and the mixing and dispersing notches 27 on two adjacent mixing sections are circumferentially offset, as shown in the reference. Figure 3 , Figure 6 and Figure 7 .

[0042] During conveying, most of the material resides at the bottom of the conveying and mixing screw, and a liquid layer 5 exists on the inner bottom of the conveying housing 1, which soaks the material. When the conveying and mixing screw rotates one revolution, the material clump 4 at the bottom of the screw is also pushed forward by one screw pitch. If the mixing and dispersing notches 27 on two adjacent mixing sections are aligned, i.e., not misaligned, refer to... Figure 4 and Figure 5 If a certain material clump 4 passes through the mixing and dispersing gap 27 without being dispersed, when it is pushed forward by one or a multiple of the pitch distance, the material clump 4 will pass through the mixing and dispersing gap 27 without being dispersed, resulting in poor bleaching effect of the material in the middle of the material clump 4 and low utilization rate of the chemical solution.

[0043] In this design, the mixing and dispersing gaps 27 on two adjacent mixing sections are circumferentially offset. Therefore, during the material pushing process, if a material clump 4 in the liquid layer 5 happens to pass through the mixing and dispersing gap 27 without being dispersed, refer to... Figure 7 When the material clump 4 is pushed forward by one or more times the pitch distance, it will be broken up by subsequent misaligned mixing and dispersing notches 27, as shown in the reference. Figure 9 This ensures that even when the liquid layer 5 under the conveying and mixing screw is relatively shallow, the material in the liquid layer 5 can still fully contact the liquid, improving the utilization rate of the liquid and thus reducing the amount of liquid added, further reducing the amount of liquid used. Preferably, the mixing and dispersing notches 27 on the multiple mixing sections are arranged in a staggered manner around the circumference.

[0044] Furthermore, referring to Figure 6 In the extending direction of the spiral blade 22, the interval angle β1 between two adjacent mixing and dispersing notches 27 is 60-65°. The mixing and dispersing notches 27 are arranged in a fan shape, and the included angle β2 between the two sides of the mixing and dispersing notches 27 with the axis of the conveying mixing screw as the center is 25-35°. Preferably, the interval angle β1 between two adjacent mixing and dispersing notches 27 is 62.5°, and the included angle β2 between the two sides of the mixing and dispersing notches 27 is 30°, that is, there are about six mixing and dispersing notches 27 in each mixing section. The mixing and dispersing notches 27 in adjacent mixing sections are staggered by 15°. Under this staggered angle, the mixing effect of material and liquid medicine is better.

[0045] In some specific embodiments, the delivery housing 1 is provided with an external liquid inlet 13, which is used to add liquid medicine to the inside of the delivery housing 1;

[0046] And / or, the inner side of the conveying shaft 21 is provided with an infusion channel 24, the end of the conveying shaft 21 is provided with an infusion port 241 communicating with the infusion channel 24, and the conveying shaft 21 is provided with an inner liquid inlet 242 communicating with the infusion channel 24. The inner liquid inlet 242 is used to add medicine into the spiral groove 23.

[0047] The liquid medicine can be added from the outer inlet 13 on the conveying housing 1, i.e., from the radially outer side of the material, and / or from the inner inlet 242 on the conveying shaft 21, i.e., from the radially inner side of the material, to contact and mix with the material. Both methods can achieve the goal of adding liquid medicine to the inner side of the conveying housing 1 and mixing it with the material. When both the outer inlet 13 and the inner inlet 242 are provided, liquid medicine can be added to both the radially outer and radially inner sides of the material, increasing the contact and mixing points between the material and the liquid medicine, reducing the mixing blind zone, thereby improving the uniformity of the mixing between the material and the liquid medicine and reducing the amount of liquid medicine to be added.

[0048] In some specific embodiments, the spiral blade 22 is provided with a feeding section 221, a dispersing and dosing section 222 and a mixing section 223 in the axial direction of the conveying shaft 21. The feeding section 221, the dispersing and dosing section 222 and the mixing section 223 are arranged sequentially in the direction from the feed inlet 11 to the discharge outlet 12. The feed inlet 11 is directly opposite the feeding section 221. The external liquid inlet 13 and the internal liquid inlet 242 are both opposite the dispersing and dosing section 222. The mixing and dispersing notch 27 is provided on the mixing section 223.

[0049] The material enters the feeding section 221 through the feed inlet 11 and is then conveyed to the dispersing and dosing section 222. The lumpy material is dispersed in the dispersing and dosing section 222, which increases the contact area with the liquid medicine. The liquid medicine is added in the dispersing and dosing section 222 and comes into contact with and mixes with the dispersed material, making the mixture of liquid medicine and material more uniform. Then the material is conveyed to the mixing section 223, where the material and liquid medicine are further stirred and mixed to ensure that the material and liquid medicine react fully for bleaching.

[0050] In some specific embodiments, reference is made to Figure 9 The spiral blade 22 located in the dispersing and dosing section 222 includes multiple dispersing teeth 25. The multiple dispersing teeth 25 are arranged at intervals along the extension direction of the spiral blade 22, and a dispersing and material passing gap 26 is provided between two adjacent dispersing teeth 25.

[0051] Because the material is compressed into clumps by the pretreatment process before bleaching, most of the material will be in clumps when it enters the feed inlet 11. This solution can break up the material by setting multiple dispersing teeth 25, so that the material can be mixed more evenly with the chemical solution after being dispersed, and the material inside the clumps can also come into contact with the chemical solution.

[0052] Preferably, the dispersing tooth 25 includes a first plate 251 and a second plate 252 connected together. Both the first plate 251 and the second plate 252 are connected to the conveying shaft 21 and extend radially along the conveying shaft 21. The first plate 251 and the second plate 252 are set at an obtuse angle. The connection angle between the first plate 251 and the second plate 252 protrudes towards the conveying direction of the spiral blade 22. The first plate 251 and the second plate 252 are both set at an angle to the tangent direction of the spiral blade 22 at the connection angle between the first plate 251 and the second plate 252. Preferably, the angle between the first plate 251 and the second plate 252 is 110°, and the width of the dispersing gap 26 is 30% of the width of the dispersing tooth 25.

[0053] When the conveying screw rotates, the corner between the first plate 251 and the second plate 252 impacts and breaks up clumps of material. The conical corner makes it easier to disperse the material. After dispersion, some material is pushed forward by the dispersing teeth 25, while the rest passes through the dispersing gap 26 along the first and second plates 251 and 252, preventing material from remaining on the dispersing teeth 25. Furthermore, the first and second plates 251 and 252 are set at an obtuse angle, and both are angled to the tangent of the spiral blade 22. This design effectively disperses the material while pushing most of it forward, maintaining high material conveying efficiency. In other embodiments, the dispersing teeth 25 can also be rectangular or circular columns.

[0054] In some specific embodiments, the infusion port 241 is connected to a rotary joint. The rotary joint is connected to a pipeline, from which the liquid medicine is transported through the rotary joint and the infusion port 241 into the infusion channel 24. The rotary joint allows for relative rotation between the pipeline and the mixing screw while the liquid medicine is being transported, preventing the mixing screw from driving the pipeline to rotate.

[0055] In some specific embodiments, reference is made to Figure 2 The external liquid inlet 13 and the internal liquid inlet 242 are equipped with atomizing nozzles, which can atomize the liquid medicine and spray it out. The liquid medicine is sprayed out through the atomizing nozzles, so that the liquid medicine is sprayed onto the material in a mist form, so that the liquid medicine and the material have a larger contact area and more uniform mixing.

[0056] The following comparative experiments were conducted on spiral mixing bleaching devices with different structures to compare the required weight of bleaching solution to achieve the same whiteness and uniformity while bleaching the same weight of fiber. In the following experiments, the same fiber was bleached using bleaching solutions of the same composition and concentration. The solutions consisted of 13.5% hydrogen peroxide, 13% sodium hydroxide solution, and a stabilizer. The stabilizer was a commercially available stabilizer known to those skilled in the art for use in fiber bleaching, primarily composed of chelating agents and sodium silicate. The amounts of sodium hydroxide solution and stabilizer were relatively fixed, with approximately 461.5 kg / ton of fiber for sodium hydroxide solution and approximately 34.2 kg / ton of fiber for stabilizer. The bleaching effect was varied by changing the amount of hydrogen peroxide.

[0057] Example 1:

[0058] The spiral mixing bleaching device includes a conveying housing 1 and a conveying and mixing screw. The conveying housing 1 is provided with an inlet 11, an outlet 12, and an external liquid inlet 13. The external liquid inlet 13 is provided with an atomizing nozzle. The conveying and mixing screw includes a conveying shaft 21, which is provided with spiral blades 22 and spiral grooves 23. The conveying shaft 21 does not have an internal liquid inlet 242. The spiral blades 22 are provided with a feeding section 221, a dispersing and adding section 222, and a mixing section 223. The dispersing and adding section 222 includes multiple dispersing teeth 25, including a first plate 251 and a second plate 252. The spiral blades 22 located in the mixing section 223 are provided with multiple mixing and dispersing notches 27. The mixing and dispersing notches 27 on two adjacent mixing sections are arranged opposite each other, that is, the interval angle between two adjacent mixing and dispersing notches 27 is 60°. The mixing and dispersing notches 27 are arranged in a fan shape, and the included angle between the two sides of the mixing and dispersing notches 27 is 30°.

[0059] Example 2:

[0060] The structure of Embodiment 2 is basically the same as that of Embodiment 1, except that the mixing and dispersing notches 27 on two adjacent mixing sections are circumferentially offset, and the interval angle β1 between two adjacent mixing and dispersing notches 27 is 62.5°.

[0061] Example 3:

[0062] The structure of Embodiment 3 is basically the same as that of Embodiment 1, except that an internal liquid inlet 242 is provided on the conveying shaft 21.

[0063] Example 4:

[0064] The structure of Example 4 is basically the same as that of Example 3, except that the mixing and dispersing notches 27 on two adjacent mixing sections are circumferentially offset, and the interval angle β1 between two adjacent mixing and dispersing notches 27 is 62.5°.

[0065] The comparison results of Examples 1, 2, 3, and 4 above are shown in the table below:

[0066]

[0067] As shown in the table above, comparing Example 2 with Example 1, the hydrogen peroxide saving is approximately 7.1%. Using the staggered mixing and dispersing notch 27 reduces the amount of chemical solution used more than using the aligned mixing and dispersing notch 27. Comparing Example 3 with Example 1, the hydrogen peroxide saving is approximately 2.4%. Using the outer and inner sides for liquid addition further reduces the amount of chemical solution used. Example 4 shows that using the staggered mixing and dispersing notch 27 and the outer and inner sides for liquid addition is the most effective, with a hydrogen peroxide saving of up to 11.9%. This can further save the amount of chemical solution used and reduce bleaching costs. Based on an annual fiber processing capacity of 300,000 tons, the market price of 13.5% concentration hydrogen peroxide is approximately 286.9 yuan / ton, which can reduce the bleaching chemical solution cost by approximately 3.1846 million yuan / year.

[0068] In addition, Figure 10(a) is a photograph of the fiber after bleaching using the existing spiral mixing structure, and Figure 10(b) is a photograph of the fiber after bleaching using the spiral mixing bleaching device of Embodiment 4 of the present invention. A comparison of the fiber bleaching effects in Figures 10(a) and 10(b) shows that, using the same amount of bleaching solution, the whiteness of the fiber obtained by bleaching using the existing technology is insufficient and the uniformity is low; while the whiteness and uniformity of the fiber obtained using Embodiment 4 of this invention are both higher.

[0069] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A spiral mixing bleaching device for plant fibers, characterized in that, The device includes a conveying housing (1) and a conveying mixing screw. The conveying housing (1) is provided with an inlet (11) and an outlet (12). The conveying mixing screw includes a conveying shaft (21), which is rotatably connected to the conveying housing (1). The conveying shaft (21) is provided with a spiral blade (22) and a spiral groove (23). The spiral blade (22) and the spiral groove (23) are located on the inner side of the conveying housing (1). The spiral blade (22) and the spiral groove (23) can convey the material from the inlet (11) to the outlet (12). The spiral blade (22) is provided with a plurality of mixing and dispersing notches (27). The plurality of mixing and dispersing notches (27) are arranged at intervals along the extension direction of the spiral blade (22). The mixing and dispersing notches (27) are connected to the spiral grooves (23) located on both sides. The conveying housing (1) is provided with an external liquid inlet (13), which is used to add liquid medicine to the inside of the conveying housing (1); And / or, the inner side of the conveying shaft (21) is provided with an infusion channel (24), the end of the conveying shaft (21) is provided with an infusion port (241) communicating with the infusion channel (24), and the conveying shaft (21) is provided with an inner liquid inlet (242) communicating with the infusion channel (24). The inner liquid inlet (242) is used to add medicine into the spiral groove (23); The spiral blade (22) is provided with a feeding section (221), a dispersing and dosing section (222), and a mixing section (223) in the axial direction of the conveying shaft (21). The feeding section (221), the dispersing and dosing section (222), and the mixing section (223) are arranged sequentially in the direction from the feed inlet (11) to the discharge outlet (12). The feed inlet (11) is directly opposite the feeding section (221). The external liquid inlet (13) and the internal liquid inlet (242) are both corresponding to the dispersing and dosing section (222). The mixing and dispersing notch (27) is provided on the mixing section (223). The spiral blade (22) located in the dispersing and dosing section (222) includes a plurality of dispersing teeth (25), which are arranged at intervals along the extension direction of the spiral blade (22), and a dispersing and material passing gap (26) is provided between two adjacent dispersing teeth (25). The dispersing tooth (25) includes a first plate (251) and a second plate (252) connected together. The first plate (251) and the second plate (252) are both connected to the conveying shaft (21) and extend radially along the conveying shaft (21). The first plate (251) and the second plate (252) are set at an obtuse angle. The connection corner of the first plate (251) and the second plate (252) protrudes toward the conveying direction of the spiral blade (22). The first plate (251) and the second plate (252) are both set at an angle to the tangent direction of the spiral blade (22) at the connection corner of the first plate (251) and the second plate (252).

2. The spiral mixing bleaching apparatus as described in claim 1, characterized in that, The mixing section is a portion of the pitch length of the spiral blade (22), and the mixing and dispersing notches (27) on two adjacent mixing sections are circumferentially misaligned.

3. The spiral mixing bleaching apparatus as described in claim 2, characterized in that, In the extending direction of the spiral blade (22), the interval angle β1 between two adjacent mixing and dispersing notches (27) is 60-65°, the mixing and dispersing notches (27) are arranged in a fan shape, and the included angle β2 between the two sides of the mixing and dispersing notches (27) is 25-35°.

4. The spiral mixing bleaching apparatus as described in claim 1, characterized in that, The infusion port (241) is connected to a rotary joint.

5. The spiral mixing bleaching apparatus as described in claim 1, characterized in that, The external liquid inlet (13) and the internal liquid inlet (242) are equipped with atomizing nozzles, which can atomize the liquid medicine and spray it out.

6. The spiral mixing bleaching apparatus as described in claim 1, characterized in that, The spiral mixing bleaching device also includes a drive motor (3), which is fixed relative to the conveying housing (1) and is connected to the conveying shaft (21) in a transmission connection.

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