A compound defoaming device for a reaction kettle

Abstract

The utility model discloses a kind of composite defoaming devices of reaction kettle, including the circulation pump cooperation with reaction kettle, spray pipe, folding leaf demulsifier and agitator, spray pipe, folding leaf demulsifier and agitator are located in reaction kettle, circulation pump is communicated with spray pipe and the discharge pipe of reaction kettle respectively by pipeline;Agitator is concentric double-shaft agitator, to the outer shaft of concentric double-shaft agitator is equipped with coupling sleeve, and upper layer stirring paddle is equipped on coupling sleeve, to the inner shaft of concentric double-shaft agitator is equipped with lower layer stirring paddle.The utility model is combined by coaxial bidirectional stirring, folding leaf demulsifier and reaction kettle internal circulation spray mode, reach the purpose of eliminating foam in reaction kettle, simultaneously, it is helpful to the dispersion and mixing of material in reaction kettle, improve material reaction efficiency.

Description

Technical Field

[0001] This utility model relates to a composite defoaming device for reaction vessels, specifically a defoaming device based on multi-structure synergy to effectively remove foam from reaction vessels, belonging to the field of defoaming technology for chemical equipment. Background Technology

[0002] In chemical production, reaction vessels are crucial equipment for chemical reactions. However, in many chemical reactions, foam is easily generated due to the interaction of reactants, solvents, or additives. The presence of foam can lead to numerous problems, such as: foam affecting the thorough mixing of reactants, reducing reaction efficiency, and impacting product quality; foam increasing pressure within the reaction vessel, posing safety hazards; and foam causing the liquid level inside the reaction vessel to rise, potentially leading to overflow of reactants and affecting production efficiency, etc. Currently, methods for eliminating foam in production mainly include adding defoamers and mechanical defoaming. However, these methods have certain limitations. For example, defoamers may introduce new impurities, which is detrimental to product purity; mechanical defoaming has a complex structure, which may lead to increased equipment and maintenance costs, and high energy consumption. For instance, multi-stage turbine defoamers, although highly efficient in removing foam, rely on precision components, and long-term operation presents challenges related to wear and maintenance.

[0003] In the prior art, utility model patent CN214808625U reports a defoaming device for a reaction vessel. The reaction vessel adopts a blade-type stirred vessel body, and the stirring shaft and vessel body structure of the reaction vessel are improved. An arc-shaped baffle is set on the upper part of the stirring shaft, which is installed at the corresponding position where bubbles are generated in the vessel body. The first step of defoaming is performed by collision and agitation, and the foam is driven to the outer side. In the upper part of the vessel body corresponding to the foam generation area, a drainage chamber protruding from the vessel body is set, and the drainage chamber is separated from the interior of the vessel body by a partition. A mesh is set in the middle of the drainage chamber. The inlet chamber is divided into an upper connecting chamber and a lower reflux chamber. The connecting chamber is connected to the inside of the reactor through a water inlet, allowing the solution inside the reactor to continuously enter the connecting chamber through the water inlet. As it enters, the foam flows towards the partition plate along with the solution and continuously impacts the defoaming needles, forming the second step of defoaming. A circulation pump is installed at the bottom of the reflux chamber. The circulation pump directly pumps the filtered solution into the lower part of the reactor, thus forming an internal circulation. This allows the solution on the upper surface to carry the foam into the inlet chamber to defoam, and at the same time, it allows the upper solution to enter the lower part, improving the uniformity of mixing. The following problems may arise during the practical application of this patented structure: First, when the viscosity of the material in the reactor is high, it enters the inlet chamber through stirring. Although the design of the inlet chamber and the partition is intended to guide the foam to collide with the defoaming needle, if the foam generation rate is too fast or the defoaming efficiency is insufficient, the foam may accumulate in the inlet chamber, affecting the defoaming effect. Second, the design and position selection of the defoaming needle have a direct impact on the defoaming efficiency of the device. If the shape, size, or position of the defoaming needle is inappropriate, it may not be able to effectively defoam. Third, the maintenance and cleaning of components such as the inlet chamber, partition, defoaming needle, and circulation pump are difficult, and the convenience of operation and the frequency of maintenance need to be considered in the later stages.

[0004] In addition, utility model patent CN214716584U reports a spiral defoaming device for a reactor, including a rotating shaft and a stirring rod vertically fixed on the rotating shaft. Several defoaming rods are horizontally arranged on the stirring rod, with the center of each defoaming rod fixed to the stirring rod. Spiral defoaming needles are fixed to both ends of each defoaming rod, and a wall-scraping brush adapted to the reactor wall is also provided at the outer end of the stirring rod. In use, the waste liquid is stirred by the stirring rod inside the reactor, while the tips of the defoaming needles defoam the air bubbles to improve the defoaming effect. The wall-scraping brush is used to clean the reactor wall, effectively preventing the concentrated liquid from remaining on the wall. However, in actual operation, the spiral defoaming device may increase system energy consumption, especially when the stirring speed and force are too high. This may cause the bubbles to break instead of defoaming, thus increasing foam production. If the foam production rate is too fast, it is still difficult to control the foam, and there is a lack of synergistic effect from multiple defoaming devices. Utility Model Content

[0005] The purpose of this invention is to provide a composite defoaming device for a reaction vessel. By combining coaxial bidirectional stirring, a folding vane demister, and internal circulating spraying within the reaction vessel, it achieves the purpose of eliminating foam within the reaction vessel. At the same time, it helps to disperse and mix the materials within the reaction vessel, thereby improving the material reaction efficiency.

[0006] This utility model is achieved through the following technical solution: a composite defoaming device for a reaction vessel, comprising a circulating pump, a spray pipe, a folding vane demister, and a stirrer that cooperate with the reaction vessel. The spray pipe, the folding vane demister, and the stirrer are all located inside the reaction vessel. The circulating pump is connected to the spray pipe and the discharge pipe of the reaction vessel through pipelines respectively. The stirrer is a concentric double-shaft stirrer. A coupling sleeve is provided on the outer shaft of the concentric double-shaft stirrer, and an upper stirring blade is provided on the coupling sleeve. A lower stirring blade is provided on the inner shaft of the concentric double-shaft stirrer.

[0007] The upper impeller is a single-layer flat-blade impeller, and the lower impeller is a double-layer propulsion impeller.

[0008] The blade diameter of the single-layer straight-blade agitator is 1 / 2 to 3 / 4 of the inner diameter of the reactor.

[0009] The distance between the single-layer straight-blade agitator and the double-layer propulsion agitator is 2 / 5 to 4 / 5 of the total length of the agitator shaft inside the vessel.

[0010] In the double-layer propulsion agitator, the distance between the two layers of agitator blades is 1 / 5 to 3 / 5 of the diameter of the agitator blades.

[0011] The spray pipe is located above the upper agitator, and the folding blade demister is located above the spray pipe.

[0012] The spray pipe has several spray holes, and the interval between the spray holes is 5 to 10 cm.

[0013] The reactor is provided with a feed inlet and an exhaust port at the top and a discharge port at the bottom. The discharge pipe is connected to the discharge port and is equipped with a control valve V1. The circulating pump is connected between the discharge port and the control valve V1 through a pipeline and is equipped with a control valve V2 on the pipeline.

[0014] Compared with the prior art, this utility model has the following advantages and beneficial effects: (1) This utility model combines a circulating pump with a sprayer to realize the circulation and spraying of materials in the reactor. The material circulation can make the liquid flow more uniform, which helps to distribute the foam evenly and avoid local foam accumulation. At the same time, combined with the impact of the spray water flow, larger foams can be broken down into smaller bubbles, making them easier to dissipate. Therefore, the combination of the two can significantly improve the defoaming efficiency. (2) By setting up a circulating pump, this utility model utilizes the circulating flow of materials inside the reactor, which also helps to bring the foam to the surface of the reactor or the discharge port in a timely manner, reducing the accumulation of foam in the reactor and reducing the impact of foam on the reaction.

[0015] (3) By setting up a concentric double-shaft agitator, this utility model can improve the material mixing efficiency in the reactor, ensure that the foam is evenly dispersed in the whole liquid, reduce local foam accumulation, and make it easier to eliminate the foam. On the other hand, the complex flow pattern generated by the double-shaft agitator when it rotates can increase the turbulence of the liquid, which helps to break the foam into smaller bubbles, thereby accelerating the dissipation of the foam.

[0016] (4) In this utility model, the concentric twin-shaft agitator adopts a single-layer straight blade agitator in the upper layer and a double-layer propulsion agitator in the lower layer. The structure of the double-layer propulsion agitator can generate radial and axial flow, which helps to disperse and mix materials, thereby improving the reaction efficiency of materials in the reactor.

[0017] (5) The present invention uses a folding blade demister installed in the upper part of the reactor to effectively prevent the "boiling over" accident caused by foam accumulation when the reaction in the reactor is violent and the circulating spray system cannot completely eliminate the foam, thereby achieving further elimination of foam. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] Figure 2 This is a schematic diagram of the structure of the folding blade demister in this utility model.

[0020] Among them, 1—reaction vessel, 2—circulating pump, 3—spray pipe, 4—discharge pipe, 5—concentric double-shaft agitator, 6—coupling sleeve, 7—upper layer agitator, 8—lower layer agitator, 9—folding blade demister, 10—spray hole, 11—feed inlet, 12—vent hole, 13—discharge port, 14—control motor. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0022] Example: This embodiment is a composite defoaming device for a reaction vessel, the structure of which is as follows: Figure 1As shown, the main components include a circulating pump 2, a spray pipe 3, and a stirrer that work in conjunction with the reactor 1. Both the spray pipe 3 and the stirrer are located inside the reactor 1. The stirrer is a concentric twin-shaft stirrer 5, consisting of an upper stirring paddle 7 and a lower stirring paddle 8. The spray pipe 3 is located above the upper stirring paddle 7. The circulating pump 2 is located outside the reactor 1 and is connected to both the spray pipe 3 and the reactor 1's discharge pipe 4 via pipes. It is used to pump the material from the discharge pipe 4 to the spray pipe 3 via the circulating pump 2, and then spray it downwards into the reactor 1. Thus, the defoaming effect is achieved through the circulating spraying of the material inside the reactor 1 by the concentric twin-shaft stirrer 5 and the material itself.

[0023] Specifically, the structure of the concentric twin-shaft stirrer 5 is as follows: Figure 1 As shown, a control motor 14 for a concentric twin-shaft agitator 5 is installed at the top of the reactor 1. The agitator 5 consists of two concentric shafts, an inner and an outer one, and the rotation of the outer and inner shafts is controlled by the control motor 14. Different types of agitators are mounted on the outer and inner shafts respectively. In this embodiment, an upper agitator 7, such as a single-layer straight-blade agitator, is installed on the outer shaft. It is assembled with the outer shaft through a coupling sleeve 6. During operation, the outer shaft is rotated by the control motor 14, which helps to push away bubbles on the surface of the liquid in the reactor 1. Since the density of bubbles is usually less than that of liquid, the residence time of bubbles in the liquid is shortened, and the possibility of bubbles accumulating or growing in the liquid is also reduced, thus helping to maintain a low foam level. A lower agitator 8, such as a double-layer propeller agitator, is installed on the inner shaft. The double-layer propeller agitator consists of two layers of coaxially mounted propeller blades. Guided by the second layer of blades, the fluid is propelled in the direction along the impeller axis, thereby generating a significant axial velocity component. As fluid passes through the impeller blades, both layers of blades induce a radial velocity component in the fluid in a direction perpendicular to the axis. The first layer of blades may exert a centripetal force on the fluid, causing it to move horizontally, while the second layer of blades further enhances this effect, especially in the inducer region, where the fluid is guided and accelerated, forming a relatively closed flow loop. This can propel the fluid outwards, creating a radial flow from the center to the edge, which helps mix fluids at different levels (the rotation of the impeller blades generates centrifugal force, forcing fluid particles to move outwards). Therefore, in this embodiment, the dual-layer propulsion impeller configuration generates both radial and axial flow, while the agitation of the single-layer straight-blade impeller helps to evenly disperse foam throughout the liquid, reducing localized foam accumulation. Simultaneously, the complex flow patterns generated by the rotation help break up the foam, forming smaller bubbles that dissipate more easily.

[0024] In a specific implementation example, for a single-layer straight-blade agitator, the blade diameter can be controlled according to the inner diameter of the reactor 1. When the reactor 1 has a large diameter, the blade diameter can be set to approximately 1 / 3 of the inner diameter of the reactor 1; when the reactor 1 has a small diameter, the blade diameter can be set to approximately 2 / 3 of the inner diameter of the reactor 1. Additionally, for a double-layer propeller agitator, two layers of agitator blades with the same diameter can be configured. The distance between the two layers of agitator blades can be determined based on their diameters. A possible option is to set the distance between the two layers of agitator blades to 1 / 5 to 3 / 5 of the blade diameter. Furthermore, when setting the distance between a single-layer straight-blade agitator and a double-layer propeller agitator, it can be determined based on the length of the stirring shaft inside the reactor. A possible option is to set the distance between the single-layer straight-blade agitator and the double-layer propeller agitator to 2 / 5 to 4 / 5 of the total length of the stirring shaft inside the reactor. The distance between the single-layer straight blade agitator and the double-layer propulsion agitator specifically refers to the distance between the upper agitator blade and the single-layer straight blade agitator in the double-layer propulsion agitator.

[0025] In this embodiment, a circulating spray system consisting of a circulating pump 2 and a spray pipe 3 enables the circulating flow of materials within the reactor, reducing localized foam accumulation and improving defoaming efficiency. It also helps to promptly carry foam to the surface of the reactor 1 or the discharge port 13, reducing foam accumulation within the reactor. Figure 1 The results show that reactor 1 has a feed inlet 11 and an exhaust port 12 at the top, and a discharge port 13 at the bottom. A discharge pipe 4 is connected to the discharge port 13 and is equipped with a control valve V1. A circulation pump 2 is connected between the discharge port 13 and the control valve V1 via a pipe, and a control valve V2 is installed on this pipe. During operation, by controlling the flow rates of control valves V1 and V2, some material can be returned to reactor 1 via the spray pipe 3 after passing through the circulation pump 2. The spray pipe 3 is located above the double-layer propeller impeller and above the liquid surface inside reactor 1. The impact force of the spray water flow can break up larger foams, decomposing them into smaller bubbles. These smaller bubbles are easier to dissipate. Based on the principles of surface tension disruption and turbulent mixing, the spacing between the spray holes 10 can be set to 5–10 cm to achieve a good defoaming effect. The aforementioned surface tension disruption refers to the phenomenon where, when water flows through a nozzle, the sudden pressure change and impact break up gas molecules attached to the surface of water droplets, reducing the surface tension of the liquid and allowing more air to be replaced by the liquid. Turbulent mixing refers to the jet kinetic energy generated by the spray creating eddies in the water. This turbulent mixing helps break small air bubbles into even smaller microbubbles and thoroughly mix them with the water. Smaller microbubbles are more likely to escape to the surface in subsequent processes, thus achieving elimination.

[0026] Furthermore, in this embodiment, a folding demister 9 is added to the top of the reactor, and its installation position is higher than that of the spray pipe. (Reference) Figure 2 As shown, the folding vane demister 9 can adopt a rectangular folding plate structure with a spiral flow channel inside. When the reaction inside the vessel is so intense that the circulating spray system cannot completely eliminate the foam, this device can effectively prevent the "overflowing" phenomenon caused by foam accumulation through the physical barrier and flow guidance effect of the spiral channel, thus achieving secondary foam elimination.

[0027] In a specific implementation case, the flow rate of the circulating pump 2 can be adjusted according to the size of the spray water flow in the spray pipe 3 inside the vessel, so as to achieve flow control of control valve V1 and control valve V2 at the same time.

[0028] In summary, this utility model achieves defoaming through multi-structure composite during implementation. It eliminates foam through the combined action of the circulating pump 2 within the reactor, the water flow impact of the sprayer, and the concentric twin-shaft agitator 5. This reduces the need for defoamer, the introduction of impurities, and production costs. Furthermore, the material circulation within the reactor improves the reaction efficiency of the materials, making it highly valuable for industrial applications.

[0029] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A composite defoaming device for a reaction vessel, characterized in that: The reactor includes a circulating pump (2), a spray pipe (3), a folding demister (9), and a stirrer that work with the reactor (1). The spray pipe (3), the folding demister (9), and the stirrer are all located inside the reactor (1). The circulating pump (2) is connected to the spray pipe (3) and the discharge pipe (4) of the reactor (1) through pipes. The stirrer is a concentric double-shaft stirrer (5). A coupling sleeve (6) is provided on the outer shaft of the concentric double-shaft stirrer (5). An upper stirring paddle (7) is provided on the coupling sleeve (6), and a lower stirring paddle (8) is provided on the inner shaft of the concentric double-shaft stirrer (5).

2. The combined defoaming device for reaction kettle according to claim 1, characterized in that: The upper stirring blade (7) is a single-layer flat blade stirring blade, and the lower stirring blade (8) is a double-layer propulsion stirring blade.

3. The combined defoaming device for reaction kettle according to claim 2, characterized in that: The diameter of the blade of the single-layer straight blade agitator is 1 / 3 to 2 / 3 of the inner diameter of the reactor (1).

4. The combined defoaming device for reaction kettle according to claim 2, characterized in that: The distance between the single-layer straight-blade agitator and the double-layer propulsion agitator is 2 / 5 to 4 / 5 of the total length of the agitator shaft inside the vessel.

5. The combined defoaming device for reaction kettle according to claim 2, characterized in that: In the double-layer propulsion agitator, the distance between the two layers of agitator blades is 1 / 5 to 3 / 5 of the diameter of the agitator blades.

6. The combined defoaming device for reaction kettle according to claim 1, characterized in that: The spray pipe (3) is located above the upper stirring paddle (7), and the folding blade demister (9) is located above the spray pipe (3).

7. The combined defoaming device for reaction kettle according to claim 6, characterized in that: The spray pipe (3) has several spray holes (10) with a spacing of 5 to 10 cm between them.

8. The reaction kettle combined defoaming device according to claim 1, characterized in that: The reactor (1) is provided with a feed inlet (11) and an exhaust port (12) at the top, and a discharge port (14) at the bottom. The discharge pipe (4) is connected to the discharge port (14) and is provided with a control valve V1. The circulating pump (2) is connected between the discharge port (14) and the control valve V1 through a pipe and is provided with a control valve V2 on the pipe.

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