A reaction tank with inclined guide plates

Abstract

The present invention discloses a reaction tank with inclined guide plates, comprising a reaction tank body, a plurality of downward-turning guide plates and upward-pressure guide plates obliquely arranged on the inner wall of the reaction tank body, wherein the plurality of downward-turning guide plates are arranged in a spiral shape at the upper position of the inner wall of the reaction tank body, and the plurality of upward-pressure guide plates are arranged in a spiral shape at the lower position of the inner wall of the reaction tank body, the spiral arrangement directions of the downward-turning guide plates and the upward-pressure guide plates are opposite, and a gap is maintained between the downward-turning guide plates and the inner wall, the spiral arrangement direction of the downward-turning guide plates is at an angle of attack to the rotation direction of the blades configured in the reaction tank body, and the spiral arrangement direction of the upward-pressure guide plates is at the same angle to the rotation direction of the blades configured in the reaction tank body. The present invention solves the problems of uneven material mixing, poor liquid flow, and unreasonable heat distribution in traditional reaction tanks through a unique guide plate design, effectively improves the reaction efficiency and product quality of phosphoric acid and phosphogypsum production, and improves production efficiency.

Description

Technical Field

[0001] The invention relates to wet-process phosphoric acid process equipment, in particular to a reaction tank with an inclined guide plate. Background Art

[0002] The wet-process phosphoric acid process primarily uses sulfuric acid to decompose phosphate rock, causing it to react and produce phosphoric acid and calcium sulfate. Through acid hydrolysis, filtration, and purification, the phosphoric acid is separated from impurities. This process is mature and has a large production scale, but it presents issues such as the treatment of phosphogypsum waste residue and the improvement of product purity. The treatment of phosphogypsum solid waste has been a persistent problem in this field. Currently, researchers have improved the process to enable the wet-process phosphoric acid process to produce not only qualified phosphoric acid, but also a phosphogypsum byproduct that meets industrial standards and reusable auxiliary materials, fundamentally resolving the challenges of traditional phosphogypsum solid waste treatment.

[0003] In the wet-process phosphoric acid production process, the reaction tank plays a central role and is a key piece of equipment throughout the entire process. Equipped with a highly efficient stirring device, the reaction tank ensures thorough and uniform mixing of the phosphate rock slurry and sulfuric acid through precise stirring. This efficient mixing not only accelerates the reaction process and improves efficiency, but also ensures a thorough reaction, crucially impacting the yield and quality of phosphoric acid and the quality of phosphogypsum.

[0004] However, current reactors still present numerous problems. First, the stirring effect is suboptimal, especially in large reactors, where material mixing uniformity is significantly insufficient. The degree of reaction varies significantly near the tank walls and in areas away from the agitator. This results in abnormally high sulfuric acid concentrations in some areas and localized accumulation of phosphate rock slurry. These issues not only reduce the yield and quality of phosphoric acid but also lead to unstable quality of phosphogypsum and uneven distribution of impurities. Second, the liquid flow within the tank is poor. After the reaction is complete, the separation of the phosphoric acid and phosphogypsum slurries becomes difficult. Dead zones exist in the liquid flow, causing some phosphogypsum slurry to remain. This not only reduces production efficiency but also obscures the separation interface due to the turbulent fluid flow, further increasing the load on subsequent separation equipment and severely affecting the separation effect and final product quality. Third, because the reaction is exothermic, the heat distribution within the reactor is uneven. Temperatures are higher in areas with intense reaction, while temperatures are relatively lower in areas further from the reaction zone. This temperature difference not only affects the reaction rate and extent, and thus the production quality of wet-process phosphoric acid products, but also can cause localized deformation and cracking of equipment, shortening its service life. Furthermore, existing reactors lack flexibility to cope with varying production scales and raw material characteristics. When faced with adjustments to production scale or changes in phosphate rock quality, the reaction conditions within the reactors are often difficult to adapt quickly and effectively, leading to production instability and significant fluctuations in product quality.

[0005] In summary, the current wet-process phosphoric acid production reactors have numerous deficiencies in key areas such as material mixing efficiency, liquid flow characteristics, heat transfer, and production adaptability, which have seriously impacted production efficiency and product quality. Therefore, improvements to the reactors are urgently needed to address these issues and enhance the overall performance of wet-process phosphoric acid production. Summary of the Invention

[0006] In response to the above-mentioned problems of the prior art, the present invention provides a reaction tank with an inclined guide plate. The guide plate with an upward pressing and downward flipping structure design effectively solves the problems of uneven material mixing and unsatisfactory liquid flow in the reaction tank.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A reaction tank with inclined guide plates comprises a reaction tank body, a plurality of downward-turning guide plates and upward-pressure guide plates obliquely arranged on the inner wall of the reaction tank body, wherein the plurality of downward-turning guide plates are arranged in a spiral pattern at the upper portion of the inner wall of the reaction tank body, and the plurality of upward-pressure guide plates are arranged in a spiral pattern at the lower portion of the inner wall of the reaction tank body. The spiral patterns of the downward-turning guide plates and the upward-pressure guide plates are arranged in opposite directions, the spiral patterns of the downward-turning guide plates are arranged at an angle of attack to the rotation direction of the paddles disposed in the reaction tank body, and the spiral patterns of the upward-pressure guide plates are arranged at the same angle as the rotation direction of the paddles disposed in the reaction tank body. When the material in the reaction tank body is stirred, the downward-turning guide plates and the upward-pressure guide plates cause the material flow field to form multiple vortices and turbulences, continuously changing the flow pattern and promoting material mixing and reaction. This reverse spiral arrangement allows the liquid to form a more complex and reasonable flow path within the tank under the action of the stirring device. The upper liquid is turned downward by the downward-turning guide plate, and the lower liquid is pressed upward by the upward-pressing guide plate. When the two meet, they can mix the materials more fully, greatly improving the uniformity of material mixing, avoiding local accumulation, and thereby improving the phosphoric acid yield and phosphogypsum quality.

[0009] Furthermore, the downward-flipping and upward-pressing guide plates are intermittently connected to the inner wall of the reactor body via multiple connecting rods, maintaining a gap between the inner edge of the guide plate and the inner wall of the reactor body. This gap design has two advantages: first, it allows liquid to flow between the guide plate and the tank wall, increasing turbulence while saving energy and further improving mixing; second, it can reduce the resistance of the guide plate to liquid flow to a certain extent, improving liquid circulation efficiency.

[0010] Furthermore, the slope angle between the head and tail ends of the downward-turning guide plate and the upward-pressing guide plate is 15 to 60 degrees, preferably 45 degrees. Such an angle setting helps guide the liquid to flow in a specific direction, strengthen the interaction between the liquids, and promote material mixing.

[0011] Furthermore, the downward-folding deflector is tilted at an angle of attack of 0 to 30 degrees, preferably 15 degrees, relative to the vertical direction of the inner wall. The upward-pressing deflector is tilted at an angle of attack of 0 to 30 degrees, preferably 15 degrees, relative to the vertical direction of the inner wall. This tilt angle effectively controls the downward and upward pressure of the liquid, allowing for ideal circulation of the liquid within the tank, better meeting production needs.

[0012] Furthermore, four downward-folding guide plates are provided, each projecting along the axis of the reactor body for approximately one-quarter of its circumference, with a slight gap between each projection. The number and length of the upward-pressing guide plates are identical to those of the downward-folding guide plates. This design ensures effective guidance of the liquid within the tank without excessively occupying the tank space, ensuring the proper operation of the stirring device and smooth liquid flow.

[0013] Furthermore, the downward-flipping and upward-pressing guide plates are uniformly provided with multiple through-holes, with an opening ratio of 10% to 40%, preferably 35%. The through-hole design allows liquid to freely permeate both sides of the guide plates, which not only enhances the mixing effect of the liquid, but also effectively reduces the weight of the guide plates and reduces the pressure on the inner wall of the reaction tank, thereby extending the service life of the equipment.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) The present invention significantly improves the liquid stirring efficiency at the edge of the tank. In traditional reaction tanks, material accumulation often occurs in the edge area due to insufficient stirring. The inclined guide plate used in the present invention effectively changes the flow path of the liquid through its unique upward pressing and downward turning structure. Specifically, the upward-inclined guide plate can guide the liquid at the bottom of the tank to flow upward, while the downward-inclined guide plate guides the upper liquid to flow downward, so that the liquid in the edge area and the liquid in the center area can be fully exchanged. This change in liquid flow greatly improves the stirring efficiency of the liquid in the edge area, making the material mixing more uniform. Uniform mixing effectively curbs the local accumulation phenomenon, promotes the full mixing reaction of phosphate ore slurry and sulfuric acid, and thus improves the reaction efficiency, output and quality of phosphoric acid, while ensuring the stability of the quality of phosphogypsum and effectively reducing the impurity content.

[0016] (2) The present invention has a positive effect on heat transfer. Through the rational arrangement of the guide plate, the liquid flow becomes more orderly and uniform, which accelerates the transfer and diffusion of heat in the reaction tank, effectively improves the problem of uneven heat distribution caused by reaction exotherm, and avoids the adverse effects of local heat imbalance on the reaction process and product quality. In addition, good heat transfer performance also helps to improve energy utilization efficiency, reduce energy waste, and further enhance the economy and sustainability of the production process.

[0017] (3) The present invention has good production adaptability. In response to different production scale requirements and changes in raw material properties, the inclination angle, number, and distribution of the guide plates can be flexibly adjusted. This enables the reaction tank to quickly adapt to changes in production conditions and maintain a stable and efficient production state, enhancing the flexibility and controllability of the production process and providing strong support for enterprises to cope with market changes and diversified production needs. This adaptability ensures the continuity and stability of the production process, and can guarantee product quality and production efficiency even in the case of fluctuations in raw material supply or changes in production demand, thereby enhancing the market competitiveness of enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural schematic diagram of the inner wall of the reaction tank in an embodiment of the present invention.

[0019] Figure 2 This is another structural schematic diagram of the inner wall of the reaction tank in an embodiment of the present invention.

[0020] Figure 3 This is another structural schematic diagram of the inner wall of the reaction tank in an embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of the structure of the tilted arrangement of the downward-flipping guide plate in the embodiment of the present invention, corresponding to Figure 1 BB cross section of area A in the middle.

[0022] Figure 5 This is a schematic structural diagram of the inclined arrangement of the upward pressure guide plate in an embodiment of the present invention.

[0023] Figure 6 Schematic diagram of the connection structure of a downward-flipping guide plate in an embodiment of the present invention.

[0024] Figure 7 Schematic diagram of the top view of the reaction tank in the embodiment of the present invention.

[0025] The names of the parts corresponding to the reference numerals are:

[0026] 1-reaction tank body, 2-downward flip guide plate, 3-upward pressure guide plate, 4-through hole, 5-connecting rod. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings and examples. The embodiments of the present invention include but are not limited to the following examples. Example

[0028] like Figures 1 to 7 As shown, the reaction tank with inclined guide plates includes a reaction tank body 1, multiple downward-turning guide plates 2 and upward-pressure guide plates 3 arranged obliquely on the inner wall of the reaction tank body. The multiple downward-turning guide plates are arranged in a spiral pattern at the upper position of the inner wall of the reaction tank body, and the multiple upward-pressure guide plates are arranged in a spiral pattern at the lower position of the inner wall of the reaction tank body. The spiral arrangement directions of the downward-turning guide plates and the upward-pressure guide plates are opposite. The spiral arrangement direction of the downward-turning guide plates is at an angle of attack to the rotation direction of the blades configured in the reaction tank body, while the spiral arrangement direction of the upward-pressure guide plates is at the same angle as the rotation direction of the blades configured in the reaction tank body. When the material in the reaction tank body is stirred, the downward-turning guide plates and the upward-pressure guide plates cause the material flow field to form multiple vortices and turbulence, continuously changing the flow pattern, and promoting material mixing and reaction. This design not only improves the efficiency of the reaction tank, but also, through the spiral arrangement, makes the flow of liquid in the reaction tank more orderly, thereby enhancing the turbulence intensity and efficiency of the reaction process.

[0029] Its detailed structure and working process are as follows:

[0030] The reactor body typically utilizes a cylindrical tank structure, constructed from corrosion-resistant materials such as rubber-lined carbon steel or fiberglass reinforced plastics (FRP) to withstand the highly corrosive environment of the phosphate rock and sulfuric acid reaction. For example, carbon steel is widely used in acid treatment equipment, while FRP, due to its low density, high mechanical strength, and excellent corrosion resistance, is also commonly used in corrosion-resistant chemical equipment. This ensures the stability and durability of the reactor in extreme environments.

[0031] The materials used to manufacture the downward-flipping and upward-pressure deflectors can be corrosion-resistant materials that match the reactor body, such as 1.4462 stainless steel. Due to its high chromium, molybdenum, and nitrogen content, this material has excellent corrosion resistance in most environments, and even exhibits strong resistance to pitting and crevice corrosion in oxidizing and acidic solutions. The slope angle between the front and rear ends of each downward-flipping and upward-pressure deflector is configured to be 15 to 60 degrees, preferably 45 degrees, as shown in the figure. The downward-flipping deflector is tilted 0 to 30 degrees relative to the vertical direction of the inner wall in the direction of the attack angle, preferably 15 degrees, as shown in the figure. The upward-pressure deflector is tilted 0 to 30 degrees relative to the vertical direction of the inner wall in the same angle direction, preferably 15 degrees, as shown in the figure. C. This ensures that the deflector can perform optimally within the reactor.

[0032] The downward-flipping guide plate and the upward-pressing guide plate are intermittently connected to the inner wall of the reaction tank body through connecting rods 5. The connecting rods are also made of corrosion-resistant materials. During the processing, one end of multiple connecting rods is first welded or bolted to one side of the guide plate, and then the other end of the connecting rod is welded and fixed according to the pre-marked position on the inner wall of the reaction tank to form a stable connection. This also creates a gap between the inner edge of the guide plate and the inner wall of the reaction tank. The size of this gap is adjusted according to actual production needs and factors such as liquid flow rate, and is generally controlled between 1 and 15 cm. This connection method greatly enhances the stability and operational reliability of the guide plate in the reaction tank.

[0033] Four downward-flipping guide plates are arranged in a spiral pattern near the upper inner wall of the reaction tank body, with a gap of approximately 2 cm between the projections of adjacent downward-flipping guide plates along the axis of the reaction tank body. The projection length of each downward-flipping guide plate along the axis of the reaction tank body is approximately 1 / 4 of the circumference of the reaction tank body. Similarly, four upward-pressure guide plates are arranged in a spiral pattern near the lower inner wall of the reaction tank body, in the opposite direction of the spiral arrangement of the downward-flipping guide plates, with their projection length and gap settings consistent with those of the downward-flipping guide plates. This spiral arrangement further optimizes the liquid flow within the reaction tank and improves reaction efficiency.

[0034] The guide plate is uniformly provided with multiple through-holes 4. Laser drilling technology can be used to ensure the precision and uniformity of the holes, allowing the porosity to be controlled within a range of 10% to 40%, and preferably adjusted to approximately 35%. These through-holes not only increase the agitation of the liquid but also allow for interpenetration through the holes in the guide plate, further enhancing the mixing effect.

[0035] When phosphate rock slurry and sulfuric acid enter the reaction tank through the top feed port, the agitator activates, driving the liquids into a circular motion. A downward-turning guide plate tilts the upper layer of liquid downward along a spiral path. Due to its tilt angle and the leading and trailing angles, the liquid continuously mixes with the surrounding materials as it flows downward. Simultaneously, an upward-pressing guide plate pushes the lower layer of liquid upward along an opposite spiral path, where it meets the downward-turning liquid in the middle of the tank, creating a high-intensity cross-flow and achieving thorough mixing of the materials. This design significantly improves mixing efficiency and ensures a thorough reaction between the phosphate rock slurry and sulfuric acid.

[0036] During liquid flow, some liquid flows through the gap between the guide plate and the tank wall, increasing liquid disturbance. Simultaneously, the liquid interpenetrates through the through-holes in the guide plate, further enhancing mixing. As the reaction proceeds, the heat generated is evenly distributed within the reaction tank as the liquid circulates. This design not only improves mixing efficiency but also ensures uniform heat distribution through the uniform flow of liquid, thereby enhancing reaction stability and efficiency.

[0037] During operation, regularly check the stability of the guide plates and connecting rods, confirm that the guide plate holes are unobstructed, and that the gap between the guide plates and the tank wall is uniform. If any problems are found, timely maintenance and adjustments should be carried out to ensure that the reactor is always in an efficient state and avoid production interruptions caused by equipment failure.

[0038] The present invention innovates and improves the structure of the reaction tank, bringing about extremely significant beneficial effects in many aspects.

[0039] In terms of material mixing, the use of downward-turning and upward-pressing guide plates arranged in a reverse spiral pattern and with a unique tilt angle significantly improves the uniformity of material mixing within the reactor body. This fundamentally solves the problem of material accumulation at the edges of traditional reactors, allowing for full contact, mixing, and reaction between phosphate rock slurry and sulfuric acid. Actual production has demonstrated a significant increase in phosphoric acid yield of 10% to 30% compared to traditional reactors. Furthermore, this uniform material mixing significantly improves the quality of phosphogypsum and effectively reduces impurity content, laying a solid foundation for its subsequent application in high-quality building materials, chemical raw materials, and other fields.

[0040] From the perspective of liquid flow, the gap between the guide plate and the tank wall and the through-hole design on the guide plate effectively increase the disturbance and penetration of the liquid. The liquid forms a more efficient and reasonable through-flow and jet entrainment high-intensity turbulent field cycle in the tank, and the flow dead zone is almost completely eliminated. This allows the reaction products to be quickly taken out to participate in the subsequent separation process, greatly improving production efficiency. According to statistics, after adopting the reaction tank of the present invention, the production efficiency can be increased by 20% to 40%, greatly shortening the production cycle and reducing production costs.

[0041] Regarding heat distribution, thorough mixing and circulation of the liquid ensure that the heat generated by the reaction is evenly distributed within the reactor. This avoids the negative impact of uneven heat distribution on the reaction rate and extent, ensuring the stability and consistency of the reaction process, thereby further improving the stability of product quality. Furthermore, due to the uniform temperature distribution, localized damage to the reactor equipment caused by temperature stress is significantly reduced, significantly extending the equipment's service life.

[0042] Furthermore, during implementation, this embodiment eliminates the need for large-scale modifications to the overall structure of the reaction tank and the stirring device, resulting in excellent economic efficiency and feasibility. This relatively simple structural adjustment comprehensively optimizes the reaction and extraction steps in wet-process phosphoric acid production, significantly improving the company's economic benefits and production efficiency, further enhancing its market competitiveness.

[0043] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any changes that adopt the design principles of the present invention and any changes made through non-creative work on this basis should fall within the scope of protection of the present invention.

Claims

1. A reaction tank with an inclined guide plate, characterized in that: The invention comprises a reaction tank body (1), a plurality of downward-turning guide plates (2) and upward-pressure guide plates (3) obliquely arranged on the inner wall of the reaction tank body (1), wherein the plurality of downward-turning guide plates are arranged in a spiral shape at an upper position of the inner wall of the reaction tank body (1), and the plurality of upward-pressure guide plates are arranged in a spiral shape at a lower position of the inner wall of the reaction tank body (1), the spiral arrangement directions of the downward-turning guide plates (2) and the upward-pressure guide plates (3) are opposite, the spiral arrangement direction of the downward-turning guide plates (2) and the rotation direction of the blades arranged in the reaction tank body (1) are at an angle of attack, and the spiral arrangement direction of the upward-pressure guide plates (3) and the rotation direction of the blades arranged in the reaction tank body (1) are at the same angle; when the material in the reaction tank body is stirred, the downward-turning guide plates (2) and the upward-pressure guide plates (3) cause the material flow field to form multiple vortices and turbulences, continuously changing the flow pattern, and promoting material mixing and reaction; The downward-turning guide plate (2) and the upward-pressing guide plate (3) are intermittently connected to the inner wall of the reaction tank body (1) via a plurality of connecting rods, so that a gap is maintained between the inner edge of the guide plate and the inner wall of the reaction tank body (1); The downward-turning deflector (2) is inclined at 0 to 30 degrees in the direction of the angle of attack relative to the vertical direction of the inner wall; the upward-pressing deflector (3) is inclined at 0 to 30 degrees in the direction of the same angle relative to the vertical direction of the inner wall; The downward-turning guide plate (2) and the upward-pressing guide plate (3) are evenly provided with a plurality of through holes (4), with an opening rate of 10% to 40%.

2. The reaction tank with inclined guide plates according to claim 1, characterized in that: The slope angle between the head and tail ends of the downward-turning guide plate (2) and the upward-pressing guide plate (3) is 15 to 60 degrees.

3. The reaction tank with inclined guide plates according to claim 2, characterized in that: The downward-turning guide plates (2) are configured in four, and the projection length of each downward-turning guide plate in the axial direction of the reaction tank body is 1 / 4 of the circumference of the reaction tank body, and a certain gap is maintained between the projections; the number and length of the upward-pressing guide plates (3) are the same as those of the downward-turning guide plates.

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