A double-inclined flow guiding device for a reaction tank

Abstract

This utility model discloses a double-inclined flow guiding device for a reaction tank, including a reaction tank body, multiple downward-folding flow guiding plates and upward-pressing flow guiding plates inclinedly disposed on the inner wall of the reaction tank body. The multiple downward-folding flow guiding plates are arranged in a spiral shape at the upper position of the inner wall of the reaction tank body, and the multiple upward-pressing flow guiding 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-folding flow guiding plates and the upward-pressing flow guiding plates are opposite, and a gap is maintained between them and the inner wall of the reaction tank body. This utility model, through its unique flow guiding plate design, solves the problems of uneven material mixing, poor liquid flow, and unreasonable heat distribution in traditional reaction tanks, effectively improving the reaction efficiency and quality of phosphoric acid and phosphogypsum production, increasing production efficiency, and extending equipment service life.

Description

Technical Field

[0001] This utility model relates to equipment for wet-process phosphoric acid production, specifically to a double-inclined flow guiding device for a reaction tank. Background Technology

[0002] The wet-process phosphoric acid production method primarily uses sulfuric acid to decompose phosphate rock, causing a reaction that produces phosphoric acid and calcium sulfate. Through acid hydrolysis, filtration, and purification processes, phosphoric acid is separated from impurities. This process is mature and can be scaled up for large-scale production, but it faces challenges such as the treatment of phosphogypsum waste and improving product purity. The treatment of phosphogypsum solid waste has long been a difficult problem in this field. Currently, researchers have improved the process so that the wet-process phosphoric acid production method can produce qualified phosphoric acid, as well as industrially compliant phosphogypsum byproducts and reusable auxiliary materials, fundamentally solving the problem of difficult 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 in the entire process. The reaction tank is equipped with a highly efficient stirring device, which 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 reaction efficiency but also ensures the completeness of the reaction, having a decisive impact on the yield and quality of phosphoric acid and the quality of phosphogypsum.

[0004] However, the currently used reaction tanks still have many problems. First, the stirring effect is not ideal, especially in large reaction tanks, where the material mixing uniformity is significantly insufficient. Significant differences in the degree of reaction are observed around the tank walls and in areas far from the agitator. This leads to abnormally high sulfuric acid concentrations in some areas and localized accumulation of phosphate rock slurry. These problems not only reduce the yield and quality of phosphoric acid but also make the quality of phosphogypsum unstable and unevenly distributed with impurities. Second, the flow of liquid within the tank is poor. After the reaction, the separation of phosphoric acid and phosphogypsum slurry becomes difficult. So-called dead zones exist in the liquid flow, causing some phosphogypsum slurry to stagnate. This not only affects production efficiency but also, due to turbulent fluid flow, leads to an unclear separation interface, further increasing the load on subsequent separation equipment and severely impacting the separation effect and final product quality. Third, because this reaction is exothermic, the heat distribution within the reaction tank is uneven. Temperatures are higher in areas of vigorous reaction and relatively lower in areas far from the reaction zone. This temperature difference not only affects the reaction rate and extent, thus impacting the production quality of wet-process phosphoric acid, but uneven temperature can also lead to problems such as localized deformation and cracking of equipment, thereby shortening its service life. Furthermore, existing reaction tanks lack flexibility in responding to changes in production scale and raw material characteristics. When faced with adjustments to production scale or changes in phosphate rock quality, the reaction conditions within the tanks often fail to adapt quickly and effectively, leading to production instability and significant fluctuations in product quality.

[0005] In summary, the existing wet-process phosphoric acid production reactors have numerous deficiencies in key aspects such as material mixing efficiency, liquid flow characteristics, heat transfer effectiveness, and production adaptability, which have seriously affected production efficiency and product quality. Therefore, improving the reactors is urgently needed to address these issues and enhance the overall performance of wet-process phosphoric acid production. Utility Model Content

[0006] To address the problems of the prior art, this utility model provides a double-inclined flow guide device for reaction tanks. Through the flow guide plate with an upper-pressing and lower-flipping structure, it effectively solves the problems of uneven material mixing and unsatisfactory liquid flow in reaction tanks.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0008] A double-inclined flow guiding device for a reaction tank includes a reaction tank body, multiple downward-folding flow guide plates and upward-pressing flow guide plates inclinedly disposed on the inner wall of the reaction tank body. The multiple downward-folding flow guide plates are arranged in a spiral pattern at the upper part of the inner wall of the reaction tank body, and the multiple upward-pressing flow guide plates are arranged in a spiral pattern at the lower part of the inner wall of the reaction tank body. The spiral arrangement of the downward-folding flow guide plates and the upward-pressing flow guide plates is in opposite directions. This reverse spiral arrangement allows the liquid to form a more complex and reasonable flow path in the tank under the action of the stirring device. The upper layer of liquid is folded down by the downward-folding flow guide plates, and the lower layer of liquid is pressed up by the upward-pressing flow guide plates. When the two meet, they can be mixed more thoroughly, which greatly improves the uniformity of material mixing, avoids local accumulation, and thus improves the phosphoric acid yield and the quality of phosphogypsum.

[0009] Furthermore, the downward-folding and upward-pressing guide plates are intermittently connected to the inner wall of the reaction tank body via multiple connecting rods, maintaining a gap between the inner edge of the guide plate and the inner wall of the reaction tank 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 the mixing effect; 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 two ends of the downward-folding guide plate and the upward-pressing guide plate is 15 degrees to 60 degrees, preferably 45 degrees. This angle setting helps guide the liquid to flow in a specific direction, enhances the interaction between liquids, and promotes material mixing.

[0011] Furthermore, the downward-folding guide plate is inclined at 0 to 30 degrees relative to the vertical direction of the inner wall towards the stirring direction, preferably 15 degrees. The upward-pressing guide plate is inclined at 0 to 30 degrees relative to the vertical direction of the inner wall towards the stirring direction, preferably 15 degrees. This inclination angle can effectively control the downward and upward pressure of the liquid, allowing the liquid to form an ideal circulating flow in the tank, better meeting production needs.

[0012] Furthermore, four downward-folding guide vanes are configured. The projection length of each downward-folding guide vane along the axis of the reaction tank body is approximately one-quarter of the circumference of the reaction tank body, and a small gap is left between each projection. The number and length of the upward-pressing guide vanes are the same as those of the downward-folding guide vanes. This design of quantity and length ensures effective guidance of the liquid in the tank without excessively occupying the tank space, thus ensuring the normal operation of the stirring device and the smooth flow of the liquid.

[0013] Furthermore, the downward-folding guide plate and the upward-pressing guide plate are evenly provided with multiple through holes, with an opening rate of 10% to 40%, preferably 35%. The through hole design allows the liquid to freely permeate on both sides of the guide plate, which not only enhances the mixing effect of the liquid, but also effectively reduces the weight of the guide plate 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) This invention significantly improves the liquid stirring efficiency at the edge of the tank. In traditional reaction tanks, material accumulation often occurs at the edge due to insufficient stirring. The inclined guide plate used in this invention, through its unique upward-pressing and downward-flipping structure, effectively changes the liquid flow path. Specifically, the upward-inclined guide plate guides the liquid at the bottom of the tank to flow upward, while the downward-inclined guide plate guides the liquid at the top to flow downward, thereby enabling sufficient exchange between the liquid at the edge and the liquid in the center, greatly improving the stirring efficiency of the liquid at the edge, making the material mix more uniform, effectively preventing local accumulation, promoting the full reaction of phosphate rock slurry and sulfuric acid, thereby improving the reaction efficiency, yield, and quality of phosphoric acid, while maintaining the stability of phosphogypsum quality and significantly reducing impurity content.

[0016] (2) This invention has a positive effect on heat transfer. The baffle plate makes the liquid flow more orderly and uniform, accelerates the transfer and diffusion of heat in the reaction tank, effectively improves the problem of uneven heat distribution caused by exothermic reaction, and avoids the adverse effects of local heat imbalance on the reaction process and product quality. In addition, the 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) This utility model possesses excellent production adaptability. Facing varying production scales and changes in raw material characteristics, the tilt angle, quantity, and distribution of the guide vanes can be flexibly adjusted, enabling the reaction tank to quickly adapt to changes in production conditions, maintain a stable and efficient production state, and enhance the flexibility and controllability of the production process. This provides strong support for enterprises to cope with market changes and diversified production needs. This adaptability ensures the continuity and stability of the production process, guaranteeing product quality and production efficiency even under conditions of fluctuating raw material supply or changes in production demand, thereby enhancing the enterprise's market competitiveness. Attached Figure Description

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

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

[0020] Figure 3 This is a schematic diagram of another structure 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 inclined arrangement of the downward-folding guide vane in an embodiment of the present invention, corresponding to... Figure 1 Section BB of region A in the middle.

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

[0023] Figure 6 This is a schematic diagram of the connection structure of a downward-folding guide plate in an embodiment of the present invention.

[0024] Figure 7 This is a top view structural diagram of the reaction tank in an embodiment of the present invention.

[0025] The component names corresponding to the reference numerals in the attached drawings are as follows:

[0026] 1-Reaction tank body, 2-Downward-folding guide plate, 3-Upward-pressurizing guide plate, 4-Through hole, 5-Connecting rod. Detailed Implementation

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

[0028] Example

[0029] like Figures 1 to 7As shown, the reaction tank uses a double-inclined flow guiding device, including a reaction tank body 1, multiple downward-facing guide plates 2 and upward-facing guide plates 3 inclinedly arranged on the inner wall of the reaction tank body. The downward-facing guide plates are arranged in a spiral pattern at the upper part of the inner wall of the reaction tank body, and the upward-facing guide plates are arranged in a spiral pattern at the lower part of the inner wall of the reaction tank body. The spiral arrangement of the downward-facing guide plates and the upward-facing guide plates is in opposite directions. During material stirring in the reaction tank body, the downward-facing guide plates and the upward-facing guide plates cause the material flow field to form multiple eddies and turbulences, constantly changing the flow pattern and promoting material mixing and reaction. This not only improves the efficiency of the reaction tank, but also, through the spiral arrangement, makes the liquid flow in the reaction tank more orderly, thereby enhancing the turbulence intensity and efficiency of the reaction process.

[0030] Its detailed structure and working process are as follows:

[0031] The reaction tank body typically adopts a cylindrical tank structure, made of materials with good corrosion resistance, such as rubber-lined carbon steel or fiberglass, to withstand the highly corrosive environment of the reaction between phosphate rock and sulfuric acid. For example, carbon steel is widely used in acid treatment equipment, while fiberglass, due to its low density, high mechanical strength, and good corrosion resistance, is also often used to manufacture corrosion-resistant chemical equipment. This ensures the stability and durability of the reaction tank in harsh environments.

[0032] The materials used to manufacture the downward-folding and upward-pressing baffles can be corrosion-resistant materials that match the reactor body, such as 1.4462 stainless steel. This material, due to its high chromium, molybdenum, and nitrogen content, exhibits excellent corrosion resistance in most environments, even showing strong resistance to pitting and crevice corrosion in oxidizing and acidic solutions. The slope angle at both ends of each downward-folding and upward-pressing baffle is configured to be 15 degrees to 60 degrees, preferably 45 degrees, as indicated by 'a' in the figure; the downward-folding baffle is inclined towards the stirring direction at 0 degrees to 30 degrees, preferably 15 degrees, as indicated by 'b' in the figure; the upward-pressing baffle is inclined towards the stirring direction at 0 degrees to 30 degrees, preferably 15 degrees, as indicated by 'c' in the figure. This ensures optimal performance of the baffles within the reactor.

[0033] The downward-folding and upward-pressing guide plates are intermittently connected to the inner wall of the reaction tank via connecting rods 5. These connecting rods are also made of corrosion-resistant materials. During processing, one end of each connecting rod is first welded or bolted to one side of the guide plate. Then, the other end of the connecting rods is welded and fixed according to pre-marked positions on the inner wall of the reaction tank, forming a stable connection. This also creates a gap between the inner edge of the guide plate and the inner wall of the reaction tank. This gap is flexibly adjusted according to actual production needs and liquid flow rate, typically maintained within the range of 1–15 cm. This connection method ensures the stability and operational reliability of the guide plate within the reaction tank.

[0034] Four downward-folding guide vanes are arranged in a spiral pattern on the upper part of the inner wall of the reaction tank, with a gap of approximately 2 cm between the projections of adjacent downward-folding guide vanes along the axial direction of the reaction tank. The projected length of each downward-folding guide vane along the axial direction of the reaction tank is approximately 1 / 4 of the circumference of the reaction tank. Similarly, four upward-pressing guide vanes are arranged in a spiral pattern on the lower part of the inner wall of the reaction tank, in the opposite direction to the spiral arrangement of the downward-folding guide vanes, with the same projected length and gap settings. This spiral arrangement further optimizes the liquid flow within the reaction tank and improves reaction efficiency.

[0035] The guide plate has multiple uniformly distributed through holes 4. Laser drilling technology can be used to ensure the accuracy and uniformity of the holes, allowing the hole ratio to be controlled between 10% and 40%, and adjusted to an optimal 35%. These through holes not only increase the turbulence of the liquid, but also allow for mutual penetration through the through holes on the guide plate, further enhancing the mixing effect.

[0036] Once the phosphate rock slurry and sulfuric acid enter the reaction tank through the top inlet, the agitator activates, driving the liquid into a circular motion. Downward-folding baffles tumble the upper liquid along a spiral path, and due to their angled inclinations, the liquid continuously mixes with surrounding materials as it flows downwards. Simultaneously, upward-pressing baffles guide the lower liquid along the opposite spiral path, creating a high-intensity cross-flow that merges with the downward-folding liquid in the central region of the tank, ensuring thorough mixing. This design significantly improves mixing efficiency and ensures complete reaction between the phosphate rock slurry and sulfuric acid.

[0037] During liquid flow, some liquid flows through the gap between the guide plate and the tank wall, increasing liquid turbulence. Simultaneously, the liquids permeate each other through the through-holes in the guide plate, further enhancing the mixing effect. As the reaction proceeds, the generated heat is also evenly distributed within the reaction tank along with the circulating liquid. This design not only improves mixing efficiency but also ensures uniform heat distribution through the uniform flow of the liquid, thereby improving the stability and efficiency of the reaction.

[0038] During equipment operation, the stability of the guide plates and their connecting rods must be checked regularly to ensure that the through holes of the guide plates are unobstructed and that the gap between the guide plates and the tank walls remains uniform. If any problems are found, maintenance and adjustments should be made promptly to ensure that the reaction tank is always in a state of high-efficiency operation and to avoid production interruptions due to equipment failure.

[0039] This invention's innovative improvement to the structure of the reaction tank brings about many significant and beneficial effects.

[0040] In terms of material mixing, the use of a reverse spiral arrangement and uniquely designed downward-facing and upward-pressing guide plates significantly improves the uniformity of material mixing within the reaction tank. The problem of material accumulation at the edges in traditional reaction tanks is fundamentally solved, allowing for thorough mixing and efficient reaction of the phosphate rock slurry and sulfuric acid. Actual production verification shows that compared to traditional reaction tanks, phosphoric acid yield can be significantly increased by 10%–30%. Simultaneously, the uniform material mixing greatly improves the quality of phosphogypsum, effectively reducing impurity content and laying a solid foundation for its subsequent use as high-quality building materials and chemical raw materials.

[0041] From the perspective of liquid flow, the gap between the guide plate and the tank wall, as well as the through-hole design on the guide plate, effectively increases liquid turbulence and penetration. The liquid forms a more efficient and rational through-flow and jet entrainment high-intensity turbulent flow field circulation within the tank, almost completely eliminating flow dead zones. This allows reaction products to be quickly carried out to participate in subsequent separation processes, significantly improving production efficiency. Statistics show that using the reaction tank of this invention can increase production efficiency by 20% to 40%, greatly shorten the production cycle, and reduce production costs.

[0042] Regarding heat distribution, thorough mixing and circulation of the liquid ensure that the heat generated by the reaction is evenly distributed within the reaction vessel. 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 product quality stability. Furthermore, due to the uniform temperature distribution, the problem of localized damage to the reaction vessel equipment caused by temperature stress is significantly mitigated, resulting in a substantial extension of the equipment's service life.

[0043] Furthermore, this embodiment does not require large-scale modifications to the overall structure of the reaction tank and the stirring device during implementation, demonstrating good economic efficiency and feasibility. Through relatively simple structural improvements, the reaction and extraction process in wet-process phosphoric acid production has been comprehensively optimized, bringing significant economic and production efficiency gains to the enterprise and further enhancing its competitiveness in the market.

[0044] The above embodiments are merely preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any changes made based on the design principles of this utility model, or any non-creative changes made on this basis, shall fall within the scope of protection of this utility model.

Claims

1. A double-inclined flow guiding device for a reaction tank, characterized in that, The reactor includes a reaction tank body (1), a plurality of downward-folding guide plates (2) and upward-pressing guide plates (3) inclinedly arranged on the inner wall of the reaction tank body (1). The plurality of downward-folding guide plates are arranged in a spiral shape at the upper position of the inner wall of the reaction tank body (1), and the plurality of upward-pressing guide plates are arranged in a spiral shape at the lower position of the inner wall of the reaction tank body (1). The spiral arrangement directions of the downward-folding guide plates (2) and the upward-pressing guide plates (3) are opposite.

2. The double-inclined flow guiding device for the reaction tank according to claim 1, characterized in that, The downward-folding guide plate (2) and the upward-pressing guide plate (3) are intermittently connected to the inner wall of the reaction tank body (1) through multiple 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).

3. The double-inclined flow guiding device for the reaction tank according to claim 2, characterized in that, The slope inclination angle between the two ends of the downward-folding guide plate (2) and the upward-pressing guide plate (3) is 15 degrees to 60 degrees.

4. The double-inclined flow guiding device for the reaction tank according to claim 3, characterized in that, The downward-folding guide plate (2) is inclined at 0 to 30 degrees relative to the vertical direction of the inner wall towards the stirring direction.

5. The double-inclined flow guiding device for the reaction tank according to claim 4, characterized in that, The pressure guide plate (3) is inclined at 0 to 30 degrees relative to the vertical direction of the inner wall towards the stirring direction.

6. The double-inclined flow guiding device for the reaction tank according to claim 5, characterized in that, The downward-folding guide plate (2) is configured in four parts, and the projection length of each downward-folding 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 their projections; the number and length of the upward-pressing guide plate (3) are the same as those of the downward-folding guide plate.

7. The double-inclined flow guiding device for a reaction tank according to any one of claims 1 to 6, characterized in that, The downward-folding guide plate (2) and the upward-pressing guide plate (3) are evenly provided with multiple through holes (4), with an opening rate of 10% to 40%.

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