A urea stripping tower high-pressure anticorrosion system
Patent Information
- Application Number
- CN202521330254.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-26
- Publication Date
- 2026-10-16
- Estimated Expiration
- 2035-06-26
AI Technical Summary
[0003]一方面，装置产能的持续增加致使汽提塔负荷显著提高，在这种情况下，工艺介质在汽提管内的流速大幅上升，高速流动的介质不断冲刷着汽提管内壁，久而久之，造成了严重的冲刷腐蚀，这种冲刷腐蚀会使汽提管管壁逐渐变薄，不仅降低了设备的机械强度，还可能引发泄漏等安全隐患；另一方面，汽提塔负荷提升后，原有的钝化空气压缩机在打气量上暴露出明显不足，在高负荷工况下，无法提供足够的钝化空气，使得金属表面难以形成完整且有效的钝化膜，介质化学腐蚀现象加剧，化学腐蚀会导致金属材料发生化学反应而被侵蚀，进一步削弱设备的性能和可靠性
[0013] This utility model provides a first valve on the first conveying pipeline and a passivation air input component connected to the stripping tower. The first valve controls the material flow rate to adapt to different load conditions and adjusts the airflow velocity entering the stripping tower. The passivation air input component injects air into the stripping tower, causing a passivation film to form on the metal surface of the stripping pipe inside the stripping tower, reducing erosion corrosion and maintaining equipment performance and feasibility.
Smart Images
Figure CN224853822U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of urea production technology, and more specifically, to a high-pressure corrosion protection system for urea stripping towers. Background Technology
[0002] In the urea production process, the stripping tower is one of the core pieces of equipment in the high-pressure system, and its operating condition directly affects the yield and quality of urea. With the continuous expansion of urea production facilities and the improvement of production efficiency, the stripping tower faces increasingly severe corrosion problems.
[0003] On the one hand, the continuous increase in the unit's capacity has led to a significant increase in the load on the stripping tower. Under these circumstances, the flow velocity of the process medium in the stripping pipe increases dramatically. The high-speed flowing medium constantly erodes the inner wall of the stripping pipe, causing severe erosion corrosion over time. This erosion corrosion will gradually thin the stripping pipe wall, not only reducing the mechanical strength of the equipment but also potentially causing safety hazards such as leaks. On the other hand, after the stripping tower load increases, the original passivation air compressor shows a significant deficiency in air volume. Under high-load conditions, it cannot provide enough passivation air, making it difficult for a complete and effective passivation film to form on the metal surface. The chemical corrosion phenomenon of the medium intensifies, and chemical corrosion will cause the metal material to undergo chemical reactions and be corroded, further weakening the performance and reliability of the equipment. Summary of the Invention
[0004] The purpose of this application is to provide a high-pressure corrosion protection system for urea stripping towers, which can solve the technical problems mentioned in the background art.
[0005] This application provides a high-pressure corrosion protection system for a urea stripping tower, including a urea synthesis tower and a stripping tower. The outlet of the urea synthesis tower is connected to the inlet of the stripping tower via a first conveying pipe. A first valve is provided on the first conveying pipe. The stripping tower is connected to a passivation air input component for inputting passivation air into the stripping tower. The top outlet of the stripping tower is connected to a second conveying pipe, and an ammonia pumping component is connected to the second conveying pipe.
[0006] Furthermore, the passivation air input assembly includes a first passivation air compressor pump, a second passivation air compressor pump, a first delivery branch pipe, a second delivery branch pipe, and a delivery main pipe. The first passivation air compressor pump is located on the first delivery branch pipe, the second passivation air compressor pump is located on the second delivery branch pipe, the first delivery branch pipe and the second delivery branch pipe merge and are connected to the delivery main pipe, and the delivery main pipe is connected to the stripping tower.
[0007] Furthermore, a backflow valve is provided on the main delivery pipe.
[0008] Furthermore, the ammonia pumping assembly includes an ammonia pumping pipe, a first high-pressure ammonia pump, and a second high-pressure ammonia pump. The ammonia pumping pipe is connected to the second delivery pipe, and the first high-pressure ammonia pump and the second high-pressure ammonia pump are connected in parallel on the ammonia pumping pipe.
[0009] Furthermore, a second valve is provided between the first passivating air compressor pump and the main delivery pipe on the first delivery branch pipe, and a third valve is provided between the second passivating air compressor pump and the main delivery pipe on the second delivery branch pipe.
[0010] Furthermore, it also includes a stripping tower steam condensate separator, wherein the condensate outlet of the stripping tower is connected to the inlet of the stripping tower steam condensate separator via a third conveying pipe, and the outlet of the stripping tower steam condensate separator is connected to the stripping tower recovery port via a fourth conveying pipe.
[0011] Furthermore, the stripping tower steam condensate separator is connected to a preheating pipe, and a fourth valve is installed on the preheating pipe.
[0012] The beneficial effects of this utility model are:
[0013] This utility model provides a first valve on the first conveying pipeline and a passivation air input component connected to the stripping tower. The first valve controls the material flow rate to adapt to different load conditions and adjusts the airflow velocity entering the stripping tower. The passivation air input component injects air into the stripping tower, causing a passivation film to form on the metal surface of the stripping pipe inside the stripping tower, reducing erosion corrosion and maintaining equipment performance and feasibility. Attached Figure Description
[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0015] Figure 1 This is a process system diagram of some embodiments of this application;
[0016] The reference numerals in the attached figures are as follows:
[0017] 1. Urea synthesis tower; 2. Stripping tower; 3. First conveying pipeline; 4. First valve; 5. Passivating air input assembly; 51. First passivating air compressor pump; 52. Second passivating air compressor pump; 53. First conveying branch pipe; 54. Second conveying branch pipe; 55. Main conveying pipe; 6. Second conveying pipeline; 7. Ammonia pumping assembly; 71. Ammonia pumping pipe; 72. First high-pressure ammonia pump; 73. Second high-pressure ammonia pump; 8. Counterflow valve; 9. Second valve; 10. Third valve; 11. Stripping tower steam condensate separator; 12. Third conveying pipe; 13. Fourth conveying pipe; 14. Preheating pipeline; 15. Fourth valve. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0019] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0021] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0022] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0023] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Specific Implementation
[0024] like Figure 1 As shown, this application provides a high-pressure anti-corrosion system for a urea stripping tower, including a urea synthesis tower 1 and a stripping tower 2. The outlet of the urea synthesis tower 1 is connected to the inlet of the stripping tower 2 through a first conveying pipe 3. A first valve 4 is provided on the first conveying pipe 3. The stripping tower 2 is connected to a passivation air input component 5 for inputting passivation air into the stripping tower 2. The top outlet of the stripping tower 2 is connected to a second conveying pipe 6. An ammonia pumping component 7 is connected to the second conveying pipe 6. In actual application, the end of the second conveying pipe 6 away from the stripping tower 2 is connected to the ammonium carbamate mixer in the existing urea high-pressure system. The high-pressure environment is maintained by the ammonia pumping component 7 through the second conveying pipe 6. The urea synthesis tower 1 discharges into the stripping tower 2 through the first conveying pipe 3. The first valve 4 controls the material flow rate to adapt to different load conditions and adjusts the airflow velocity entering the stripping tower 2. The passivation air input component 5 injects air into the stripping tower 2, so that a passivation film is formed on the metal surface of the stripping pipe inside the stripping tower 2, reducing erosion corrosion and maintaining equipment performance and feasibility.
[0025] like Figure 1 As shown, the passivation air input assembly 5 includes a first passivation air compressor pump 51, a second passivation air compressor pump 52, a first delivery branch pipe 53, a second delivery branch pipe 54, and a delivery main pipe 55. The first passivation air compressor pump 51 is installed on the first delivery branch pipe 53, and the second passivation air compressor pump 52 is installed on the second delivery branch pipe 54. The first delivery branch pipe 53 and the second delivery branch pipe 54 merge and connect to the delivery main pipe 55. The delivery main pipe 55 is connected to the stripping tower 2. With two passivation air compressor pumps and dual delivery branch pipes, when one compressor pump malfunctions... In the event of a failure, the other pump can continue to operate, ensuring a continuous supply of passivating air and greatly improving the reliability of the system. This avoids the situation where the passivation film on the metal surface cannot be maintained due to the interruption of the passivation air supply, which would lead to accelerated chemical corrosion. In addition, the operating status of the first passivating air compressor pump 51 and the second passivating air compressor pump 52 can be flexibly controlled according to the different load requirements of the stripping tower 2. At low loads, only one pump is turned on to reduce energy consumption; at high loads, both pumps operate simultaneously to meet the demand for passivating air under high load conditions.
[0026] like Figure 1 As shown, a backflow valve 8 is provided on the main conveying pipe 55 to prevent the passivation air in the main conveying pipe 55 from flowing back, ensuring that the passivation air always flows to the stripping tower 2 in the predetermined direction, maintaining a stable supply of passivation air, ensuring the continuous formation and repair of the passivation film on the metal surface, and effectively preventing chemical corrosion.
[0027] like Figure 1 As shown, the ammonia pumping assembly 7 includes an ammonia pumping pipe 71, a first high-pressure ammonia pump 72, and a second high-pressure ammonia pump 73. The ammonia pumping pipe 71 is connected to a second conveying pipe. The first high-pressure ammonia pump 72 and the second high-pressure ammonia pump 73 are connected in parallel on the ammonia pumping pipe 71. Specifically, the end of the ammonia pumping pipe 71 away from the second conveying pipe is connected to the ammonia tank. The first high-pressure ammonia pump 72 and the second high-pressure ammonia pump 73 can pump ammonium from the ammonia tank to the second conveying pipe through the ammonia pumping pipe 71. The installation of two parallel high-pressure ammonia pumps greatly improves the reliability of the ammonia conveying system. When one pump fails, the other pump can continue to work, ensuring a continuous supply of ammonia and avoiding the shutdown of the entire urea production system due to ammonia supply interruption. The parallel pump design allows the ammonia pumping assembly 7 to adapt well to different production load changes during urea production. By flexibly adjusting the number of pumps in operation, the ammonia delivery volume and pressure can be controlled, which not only meets the high requirements for ammonia quantity and pressure during high-load production but also avoids energy waste during low-load production.
[0028] like Figure 1 As shown, a second valve 9 is provided on the first delivery branch pipe 53 between the first passivation air compressor pump 51 and the delivery main pipe 55, and a third valve 10 is provided on the second delivery branch pipe 54 between the second passivation air compressor pump 52 and the delivery main pipe 55. The second valve 9 and the third valve 10 can independently control the passivation air flow rate output by the first passivation air compressor pump 51 and the second passivation air compressor pump 52. The passivation air volume requirement is different in different operating stages of the stripping tower 2. In the start-up stage, the amount of passivation air entering the stripping tower 2 can be precisely controlled by fine-tuning the two valves to ensure that a uniform passivation film is quickly formed on the metal surface. During normal operation, the valve opening can be flexibly adjusted according to the load change to make the passivation air volume accurately match the actual demand, optimize the passivation effect, and avoid affecting the anti-corrosion performance or causing energy waste due to too much or too little air.
[0029] like Figure 1As shown, the high-pressure anti-corrosion system for a urea stripping tower according to this application also includes a stripping tower steam condensate separator 11. The condensate outlet of the stripping tower 2 is connected to the inlet of the stripping tower steam condensate separator 11 via a third conveying pipe 12. The outlet of the stripping tower steam condensate separator 11 is connected to the recovery port of the stripping tower 2 via a fourth conveying pipe 13. The condensate generated during the operation of the stripping tower 2 contains unreacted ammonia, carbon dioxide, and a small amount of urea, etc., which are valuable substances. The condensate is introduced into the stripping tower steam condensate separator 11 through the third conveying pipe 12. After separation, these substances can be recovered. The separated ammonia and carbon dioxide can be sent back to the recovery port of the stripping tower 2 through the fourth conveying pipe 13 to participate in the urea production reaction again, thereby improving the utilization rate of raw materials and reducing production costs.
[0030] like Figure 1 As shown, the stripping tower steam condensate separator 11 is connected to a preheating pipe 14, and a fourth valve 15 is installed on the preheating pipe 14. In order to avoid damage to the equipment due to the different expansion coefficients of the lining and cylinder of the urea synthesis tower 1 and the stripping tower 2, the urea synthesis tower 1 and the stripping tower 2 need to be preheated before starting. The preheating pipe 14 is connected to a steam source. Before starting, the bottom material inlet valve of the urea synthesis tower 1 is closed, and the first valve 4 and the fourth valve 15 are opened. The steam enters the stripping tower steam condensate separator 11 through the fourth pipe, and then enters the stripping tower 2 through the third pipe, and enters the urea synthesis tower 1 through the first conveying pipe 3, thereby realizing the preheating of the urea synthesis tower 1 and the stripping tower 2.
[0031] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A high-pressure corrosion protection system for a urea stripping tower, characterized in that: The system includes a urea synthesis tower and a stripping tower. The outlet of the urea synthesis tower is connected to the inlet of the stripping tower via a first conveying pipe. A first valve is provided on the first conveying pipe. The stripping tower is connected to a passivation air input component that inputs passivation air into the stripping tower. The top outlet of the stripping tower is connected to a second conveying pipe, and an ammonia pumping component is connected to the second conveying pipe.
2. The high-pressure corrosion protection system for a urea stripping tower according to claim 1, characterized in that: The passivation air input assembly includes a first passivation air compressor pump, a second passivation air compressor pump, a first delivery branch pipe, a second delivery branch pipe, and a delivery main pipe. The first passivation air compressor pump is located on the first delivery branch pipe, and the second passivation air compressor pump is located on the second delivery branch pipe. The first delivery branch pipe and the second delivery branch pipe merge and are connected to the delivery main pipe, which is connected to the stripping tower.
3. The high-pressure corrosion protection system for a urea stripping tower according to claim 2, characterized in that: A backflow valve is installed on the main delivery pipe.
4. The high-pressure corrosion protection system for a urea stripping tower according to claim 1, characterized in that: The ammonia pumping assembly includes an ammonia pumping pipe, a first high-pressure ammonia pump, and a second high-pressure ammonia pump. The ammonia pumping pipe is connected to the second delivery pipe, and the first high-pressure ammonia pump and the second high-pressure ammonia pump are connected in parallel on the ammonia pumping pipe.
5. The high-pressure corrosion protection system for a urea stripping tower according to claim 2, characterized in that: A second valve is provided between the first passivating air compressor pump and the main delivery pipe on the first delivery branch pipe, and a third valve is provided between the second passivating air compressor pump and the main delivery pipe on the second delivery branch pipe.
6. The high-pressure corrosion protection system for a urea stripping tower according to claim 1, characterized in that: It also includes a stripping tower steam condensate separator, wherein the condensate outlet of the stripping tower is connected to the inlet of the stripping tower steam condensate separator via a third conveying pipe, and the outlet of the stripping tower steam condensate separator is connected to the stripping tower recovery port via a fourth conveying pipe.
7. The high-pressure corrosion protection system for a urea stripping tower according to claim 6, characterized in that: The stripping tower steam condensate separator is connected to a preheating pipe, and a fourth valve is installed on the preheating pipe.