Novel sulfur trioxide evaporator

Abstract

The invention relates to the technical field of chemical equipment, and discloses a novel sulfur trioxide evaporator. The novel sulfur trioxide evaporator comprises a first heat exchanger, a cleaning assembly is arranged on the right side of the first heat exchanger, a protection assembly is arranged on the left side of the first heat exchanger, the cleaning assembly comprises a side plate, the side plate is arranged on the right side of the first heat exchanger, and a sliding groove is formed in the top of the side plate; a sliding plate is slidably connected into the sliding groove, a motor is fixedly connected to the side, close to the first heat exchanger, of the sliding plate, and the output end of the motor penetrates through the sliding plate to be fixedly connected with a rotating rod. Meanwhile, the composite material has the functions of leakage real-time early warning and active safety protection, and the application of the composite material greatly reduces the manufacturing cost and obviously improves the recovery efficiency of sulfur trioxide.

Description

Technical Field

[0001] This invention relates to the field of chemical equipment technology, and in particular to a novel sulfur trioxide evaporator. Background Technology

[0002] In chemical production, separating and recovering high-purity sulfur trioxide from fuming sulfuric acid is a crucial process. This process typically involves heating the fuming sulfuric acid, utilizing the difference in volatility between sulfur trioxide and sulfuric acid at different temperatures to achieve evaporation and separation. The evaporation of sulfur trioxide generally occurs within the fuming acid, which places high demands on the materials used. With 20% fuming acid evaporation and anodic protection, even a 316L stainless steel tank can only achieve a controlled temperature of 130-135℃, reducing the sulfur trioxide recovery from 20% fuming acid to 15% in a single operation, with a lifespan of approximately six months. Using tantalum materials to control the temperature at 140℃ reduces the sulfur trioxide recovery from 20% fuming acid to approximately 12%, with a lifespan of about three years, but the cost is exorbitant. In short, current processing methods are costly and inefficient.

[0003] Traditional equipment for this process, which requires handling highly corrosive fuming sulfuric acid at high temperatures, typically necessitates the use of precious metals such as tantalum alloys for integral manufacturing. This results in exceptionally high initial investment costs, limiting the technology's widespread adoption and application. Furthermore, the structural design of traditional evaporators has limitations in heat and mass transfer, often leading to low single-pass sulfur trioxide recovery efficiency, increasing energy consumption and costs.

[0004] In actual operation, process materials are prone to solid-phase precipitation on the inner wall of the heat exchanger, especially in areas of temperature change, forming a solid deposit. This deposit not only severely hinders heat transfer and reduces evaporation efficiency, but also, over time, can lead to pipe blockage, forcing the entire production line to shut down for manual cleaning. This is not only time-consuming and labor-intensive, but the cleaning process also carries extremely high safety risks.

[0005] More importantly, traditional sulfur trioxide evaporators are usually single-layer structures. Once the equipment body develops tiny cracks due to corrosion or pressure fluctuations, high-pressure, highly toxic sulfur trioxide gas will leak directly into the external environment, posing a fatal threat to operators and causing serious environmental pollution. Summary of the Invention

[0006] To overcome the above shortcomings, the present invention provides a novel sulfur trioxide evaporator, which aims to improve the problems of high manufacturing cost, low recovery efficiency, difficulty in cleaning inner wall deposits, and high risk of material leakage in the existing novel sulfur trioxide evaporators.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a novel sulfur trioxide evaporator, comprising a first heat exchanger, a cleaning component disposed on the right side of the first heat exchanger, and a protective component disposed on the left side of the first heat exchanger. The cleaning component includes a side plate disposed on the right side of the first heat exchanger. A sliding groove is formed at the top of the side plate, and a sliding plate is slidably connected inside the sliding groove. A motor is fixedly connected to the side of the sliding plate near the first heat exchanger. A rotating rod is fixedly connected through the output end of the motor and passes through the sliding plate. A gear is fixedly connected to the end of the rotating rod away from the motor. A low-frequency sound wave generator is fixedly connected to the middle of the sliding plate. A housing is fixedly connected to one end of the top of the side plate, and a rack is fixedly connected to the top wall of the housing.

[0008] As a further description of the above technical solution:

[0009] The protective assembly includes a vacuum pump, which is located on the left side of the first heat exchanger. A first pipe is fixedly connected to the input end of the vacuum pump. A nitrogen storage tank is fixedly connected to the end of the first pipe away from the vacuum pump. A second pipe is fixedly connected to the input end of the vacuum pump. A third pipe is provided at the bottom of the first heat exchanger. A drain port is provided at the bottom of the first heat exchanger. A sleeve is provided inside the first heat exchanger. A sealed interlayer is formed between the sleeve and the outer wall of the first heat exchanger. A pressure detector is provided inside the sealed interlayer.

[0010] As a further description of the above technical solution:

[0011] The first heat exchanger is connected to a falling film evaporator via a pipe, the falling film evaporator is connected to a second heat exchanger via a pipe, and the falling film evaporator is connected to a third heat exchanger via a pipe.

[0012] As a further description of the above technical solution:

[0013] The rotating rod is rotatably connected to the side of the slide plate near the gear via a bearing, and the gear meshes with the rack;

[0014] As a further description of the above technical solution:

[0015] The low-frequency sound wave generator's sound wave output terminal is located on the right side of the first heat exchanger.

[0016] As a further description of the above technical solution:

[0017] The end of the second pipe furthest from the vacuum pump is fixedly installed at the bottom of the first heat exchanger, behind the drain port.

[0018] As a further description of the above technical solution:

[0019] The third pipe is located in front of the sewage outlet;

[0020] As a further description of the above technical solution:

[0021] The outer shell of the falling film evaporator is made of enamel, and the interior of the falling film evaporator is equipped with multiple silicon carbide tubes.

[0022] The present invention has the following beneficial effects:

[0023] 1. This invention solves the problem in the prior art that solid matter easily adheres to the inner wall of the heat exchanger and is difficult to clean, thus affecting the heat exchange efficiency, by integrating a low-frequency sound wave generator with a sliding device that drives it to move axially along the first heat exchanger. This achieves online automatic cleaning, improves equipment operation stability and heat transfer efficiency.

[0024] 2. This invention solves the problems of material leakage risk, safety hazards and passive emergency response in existing pressure-bearing equipment due to the single-layer structure by setting a sleeve on the outer wall of the first heat exchanger to form a sealed jacket with pressure monitoring and connecting it to a nitrogen storage tank and an exhaust pipe. It achieves the technical effects of real-time leakage early warning, active safety protection and controllable emergency handling, and improves the safety of equipment and operation.

[0025] 3. This invention, by adopting a falling film evaporator structure that combines an enamel shell with silicon carbide tubes, and by confining the high-temperature and strong corrosion process section within the silicon carbide component, solves the problems of high manufacturing costs due to the need for expensive materials in the evaporator and low sulfur trioxide recovery rate due to insufficient heat transfer efficiency in the prior art. It achieves the goal of reducing equipment manufacturing costs while improving sulfur trioxide recovery efficiency. Attached Figure Description

[0026] Figure 1 This is a flow chart of a novel sulfur trioxide evaporator proposed in this invention;

[0027] Figure 2 This is a three-dimensional schematic diagram of the first heat exchanger of a novel sulfur trioxide evaporator proposed in this invention;

[0028] Figure 3 This is a schematic diagram of the rack structure of a novel sulfur trioxide evaporator proposed in this invention;

[0029] Figure 4 This is a schematic diagram of the nitrogen storage tank of a novel sulfur trioxide evaporator proposed in this invention.

[0030] Legend:

[0031] 1. First heat exchanger; 2. Side plate; 3. Shell; 4. Slide groove; 5. Slide plate; 6. Low-frequency sound wave generator; 7. Gear; 8. Motor; 9. Rack; 10. Sleeve; 11. Vacuum pump; 12. Second pipe; 13. First pipe; 14. Nitrogen storage tank; 15. Third pipe; 16. Rotating rod; 17. Drain outlet; 18. Falling film evaporator; 19. Second heat exchanger; 20. Third heat exchanger. Detailed Implementation

[0032] 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 some embodiments of the present invention, and not all 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.

[0033] Reference Figures 1-3This invention provides an embodiment of a novel sulfur trioxide evaporator, comprising a first heat exchanger 1. The first heat exchanger 1 is used to realize the heat exchange process of sulfur trioxide gas, providing temperature conditions for subsequent evaporation. A cleaning component is arranged on the right side of the first heat exchanger 1, and a protective component is arranged on the left side of the first heat exchanger 1. The cleaning component includes a side plate 2, which provides a mounting support base for each component of the cleaning component. The side plate 2 is located on the right side of the first heat exchanger 1. A sliding groove 4 is opened on the top of the side plate 2. The sliding groove 4 guides and limits the sliding of the slide plate 5, ensuring its linear motion accuracy. The slide plate 5 is slidably connected inside the sliding groove 4. A motor 8 is fixedly connected to the side of the slide plate 5 closest to the first heat exchanger 1. The motor 8 provides a power source for the movement of the cleaning component. A rotating rod 16 is fixedly connected to the output end of the motor 8 through the slide plate 5. The rotating rod 16 is used to transmit the rotational power of the motor 8. A gear 7 is fixedly connected to the end of the rotating rod 16 away from the motor 8. The gear 7 meshes with a rack 9 to realize power conversion, converting rotational motion into linear motion. A low-pressure plate is fixedly connected to the middle of the slide plate 5. The low-frequency sound wave generator 6 generates low-frequency sound wave energy that can penetrate the wall of the first heat exchanger 1, causing fatigue cracks in the solid sulfur trioxide adhering to the inner wall and causing it to shatter and fall off. A housing 3 is fixedly connected to one end of the top of the side plate 2. The housing 3 is used to install and fix the rack 9, and also protects the meshing area between the gear 7 and the rack 9. The rack 9 is fixedly connected to the top wall of the housing 3, providing the meshing basis for the linear motion of the gear 7. In conjunction with the gear 7, it converts the rotational power of the motor 8 into the linear reciprocating motion of the slide plate 5. The movement ensures that the low-frequency sound wave generator 6 scans stably along the axial direction of the first heat exchanger 1. The rotating rod 16 is rotatably connected to the side of the slide plate 5 near the gear 7 through the bearing. The bearing ensures that the rotating rod 16 is stable and has low friction during rotation, making the power transmission more efficient. The gear 7 meshes with the rack 9. The sound wave output end of the low-frequency sound wave generator 6 is located on the right side of the first heat exchanger 1. This layout allows the sound wave energy to act directly on the inner wall of the first heat exchanger 1, maximizing the coverage and impact of the sound wave cleaning, and effectively breaking up the attached solid sulfur trioxide.

[0034] Reference Figure 1 , Figure 2 and Figure 4The protective assembly includes a vacuum pump 11, which is used to establish a negative pressure environment within the sealed interlayer and to perform nitrogen injection and discharge operations. The vacuum pump 11 is located on the left side of the first heat exchanger 1. A first pipe 13 is fixedly connected to the input end of the vacuum pump 11, which connects the vacuum pump 11 to a nitrogen storage tank 14 for nitrogen delivery. The end of the first pipe 13 furthest from the vacuum pump 11 is fixedly connected to the nitrogen storage tank 14, which provides an inert nitrogen source for the protective assembly to dilute the leaked medium and establish a pressure environment. A second pipe 12 is fixedly connected to the input end of the vacuum pump 11, which delivers nitrogen to the sealed interlayer formed by the first heat exchanger 1 and the sleeve 10. A third pipe 15 is provided at the bottom of the first heat exchanger 1, which discharges the leaked mixed gas in the sealed interlayer into a scrubbing tower for harmless treatment. A drain port 17 is provided at the bottom of the first heat exchanger 1, which discharges the gas after being broken up by low-frequency sound waves and mixed with inert gas. The solvent-mixed slurry has a sleeve 10 inside the first heat exchanger 1. The sleeve 10 and the outer wall of the first heat exchanger 1 form a sealed interlayer, which constitutes a double-layer safety structure to realize real-time monitoring and protection against leakage. A pressure detector is installed in the sealed interlayer between the sleeve 10 and the outer wall of the first heat exchanger 1. The pressure detector is used to monitor the pressure changes in the interlayer in real time and provide timely warning of leakage. The end of the second pipe 12 away from the vacuum pump 11 is fixedly set at the bottom of the first heat exchanger 1, behind the drain port 17. This layout allows nitrogen to be delivered to the sealed interlayer between the first heat exchanger 1 and the sleeve 10. During normal operation, the interlayer is kept under negative pressure. When a leak occurs, nitrogen is quickly injected to dilute sulfur trioxide and suppress the leakage rate. The third pipe 15 is located in front of the drain port 17. This position design ensures that the leaked mixed gas can be safely discharged into the scrubbing tower through the third pipe 15 under the positive pressure of nitrogen, avoiding the leakage of toxic substances. At the same time, it is clearly distinguished from the functional area of ​​the drain port 17 and does not interfere with each other.

[0035] Reference Figure 1 The first heat exchanger 1 is connected to a falling film evaporator 18 via a pipe. The falling film evaporator 18 is the core equipment for sulfur trioxide evaporation, realizing the phase change process of sulfur trioxide from liquid to gas. The falling film evaporator 18 is connected to a second heat exchanger 19 via a pipe, and the falling film evaporator 18 is connected to a third heat exchanger 20 via a pipe. The second heat exchanger 19 and the third heat exchanger 20 are used to further heat exchange the evaporated sulfur trioxide gas or related media to ensure the process temperature requirements. The outer shell of the falling film evaporator 18 is made of enamel, which has low cost and good temperature resistance and is suitable for non-strongly corrosive process sections, reducing equipment manufacturing costs. The falling film evaporator 18 is equipped with multiple silicon carbide tubes inside. Silicon carbide tubes have excellent resistance to strong corrosion and high thermal conductivity, making them suitable for high-temperature and highly corrosive sulfur trioxide evaporation process sections, improving heat transfer efficiency and sulfur trioxide recovery efficiency.

[0036] Working principle: When it is necessary to clean the solid sulfur trioxide adhering to the inner wall of the first heat exchanger 1, the cleaning system installed on the shell 3 and side plate 2 starts the motor 8. After the motor 8 is powered on, the power is transmitted to the gear 7 through the rotating rod 16. The gear 7 precisely meshes with the rack 9 fixed on the slide plate 5, converting the rotational motion of the motor 8 into the linear reciprocating motion of the slide plate 5. The slide plate 5 moves stably along the preset slide groove 4, and drives the low-frequency sound wave generator 6 fixed on it to scan back and forth along the axial direction of the first heat exchanger 1. During the movement, the low frequency... The sound wave generator 6 generates powerful low-frequency sound wave energy. This energy penetrates the wall of the sleeve 10 and focuses on the high-intensity sound wave vibration of its inner wall, causing fatigue cracks in the solid sulfur trioxide layer and eventually breaking it into fragments. These fragments fall to the bottom of the heat exchanger due to gravity. After the crushing operation is completed, an inert solvent can be injected into the first heat exchanger 1. The inert solvent mixes with the crushed solid particles to form a slurry, which can then be more easily and smoothly discharged through the drain port 17 at the bottom, completing the entire cleaning and drainage process. The sleeve 10 and the first heat exchanger... A sealed interlayer space is formed between the outer walls of the first heat exchanger 1 and the outer walls, constituting a double-layer safety structure. During normal operation, the vacuum pump 11 introduces a small amount of nitrogen into the interlayer through the second pipe 12, which is monitored in real time by an internal pressure detector to maintain a stable negative pressure environment. When the sleeve 10 suffers a minor damage, the high-pressure sulfur trioxide gas inside will enter the interlayer, causing the pressure inside the interlayer to rise rapidly. After sensing the pressure change, the pressure detector will immediately issue an alarm signal. The operator will turn on the vacuum pump 11 and introduce nitrogen from the nitrogen storage tank 14 into the interlayer through the first pipe 13 and the second pipe 12. The injected nitrogen can dilute the leaked sulfur trioxide, slow down the corrosion of the outer wall of the first heat exchanger 1, and reduce the internal and external pressure difference by establishing positive pressure, thus suppressing the leakage rate. Subsequently, the valve of the third pipe 15 is opened, and the nitrogen pressure inside the interlayer is used to safely and controllably discharge the polluted gas mixed with sulfur trioxide into the external scrubbing tower for harmless treatment, thereby preventing toxic substances from leaking into the atmosphere and ensuring the safety of the equipment and the environment.

[0037] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A novel sulfur trioxide evaporator, comprising a first heat exchanger (1), characterized in that: A cleaning component is provided on the right side of the first heat exchanger (1), and a protective component is provided on the left side of the first heat exchanger (1). The cleaning assembly includes a side plate (2) which is located on the right side of the first heat exchanger (1). A groove (4) is provided on the top of the side plate (2). A slide plate (5) is slidably connected inside the groove (4). A motor (8) is fixedly connected to the side of the slide plate (5) near the first heat exchanger (1). A rotating rod (16) is fixedly connected through the output end of the motor (8) through the slide plate (5). A gear (7) is fixedly connected to the end of the rotating rod (16) away from the motor (8). A low-frequency sound wave generator (6) is fixedly connected to the middle of the slide plate (5). A housing (3) is fixedly connected to the top end of the side plate (2). A rack (9) is fixedly connected to the top wall of the housing (3).

2. The novel sulfur trioxide evaporator according to claim 1, characterized in that: The protective assembly includes a vacuum pump (11), which is located on the left side of the first heat exchanger (1). The input end of the vacuum pump (11) is fixedly connected to a first pipe (13). The end of the first pipe (13) away from the vacuum pump (11) is fixedly connected to a nitrogen storage tank (14). The input end of the vacuum pump (11) is fixedly connected to a second pipe (12). A third pipe (15) is provided at the bottom of the first heat exchanger (1). A drain port (17) is provided at the bottom of the first heat exchanger (1). A sleeve (10) is provided inside the first heat exchanger (1). A sealed interlayer is formed between the sleeve (10) and the outer wall of the first heat exchanger (1). A pressure detector is provided inside the sealed interlayer.

3. The novel sulfur trioxide evaporator according to claim 1, characterized in that: The first heat exchanger (1) is connected to a falling film evaporator (18) via a pipe, the falling film evaporator (18) is connected to a second heat exchanger (19) via a pipe, and the falling film evaporator (18) is connected to a third heat exchanger (20) via a pipe.

4. A novel sulfur trioxide evaporator according to claim 1, characterized in that: The rotating rod (16) is rotatably connected to the side of the slide plate (5) near the gear (7) via a bearing, and the gear (7) meshes with the rack (9).

5. A novel sulfur trioxide evaporator according to claim 1, characterized in that: The low-frequency sound wave generator (6) has its sound wave output end located on the right side of the first heat exchanger (1).

6. A novel sulfur trioxide evaporator according to claim 2, characterized in that: The end of the second pipe (12) away from the vacuum pump (11) is fixedly installed at the bottom of the first heat exchanger (1) behind the drain port (17).

7. A novel sulfur trioxide evaporator according to claim 2, characterized in that: The third pipe (15) is located in front of the drain outlet (17).

8. A novel sulfur trioxide evaporator according to claim 3, characterized in that: The outer shell of the falling film evaporator (18) is made of enamel, and the interior of the falling film evaporator (18) is provided with multiple silicon carbide tubes.

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