Urea synthesis tower

Abstract

The utility model provides a synthesis tower, belongs to the technical field of urea synthesis equipment, and particularly relates to a urea synthesis tower which comprises an outer shell, an inner partition plate is arranged in the outer shell, the diameter of the inner partition plate is smaller than the inner diameter of the inner partition plate, and a pair of symmetrically-distributed heat exchange devices is arranged in the inner partition plate. The upper part of the heat exchange device is communicated with a reaction structure through a gas conveying pipe, the reaction structure comprises a plurality of uniformly distributed tower trays arranged in an inner partition plate, the tower trays are connected with a plurality of small-caliber gas phase holes which penetrate through the tower trays and are densely distributed through uniformly distributed wave-shaped grooves, and the tower trays are connected through downcomers which are distributed in a staggered manner; the problems that an existing urea synthesis tower is low in efficiency and inconvenient to use are solved.

Description

Technical Field

[0001] The utility model provides a synthesis tower, belongs to the technical field of urea synthesis equipment, and particularly relates to a urea synthesis tower. Background Art

[0002] A urea reactor is a chemical reactor specifically designed for the industrial production of urea. Its primary function is to provide a suitable environment and conditions for ammonia (NH3) and carbon dioxide (CO2) to react under a specific temperature and pressure to produce urea ((NH2)2CO). A urea reactor typically consists of key components such as a tower body, trays, a heat exchanger, an exhaust hopper, and an inner shell. The trays are designed with corrugated grooves and gas-phase holes to promote sufficient contact and mixing between the gas and liquid phases, improving heat and mass transfer efficiency. This type of tower is widely used in the chemical industry, particularly in fertilizer production. Urea, as a highly efficient nitrogen fertilizer, is of great significance for increasing crop yields and promoting agricultural development. The design and operation of urea reactors are crucial to ensuring the safety, efficiency, and environmental friendliness of urea production.

[0003] The urea synthesis tower is a key piece of equipment in urea production, responsible for providing the ideal space and conditions for the chemical reaction between ammonia and carbon dioxide to produce urea. This process places strict demands on temperature, pressure, gas-liquid contact, and mass transfer efficiency to ensure adequate mixing and conversion of the reactants. However, existing designs have limitations, such as outdated tray technology, insufficient porosity, and short tray material life. These issues impact the performance of the synthesis tower and the safety, efficiency, and stability of urea production. Outdated tray technology leads to poor gas-liquid contact efficiency, affecting the speed and conversion rate of the urea synthesis reaction, potentially leading to reactant waste and the formation of by-products. Insufficient porosity directly affects gas distribution and liquid flow, reducing contact efficiency and thus impacting synthesis efficiency. Issues with the tray material life, such as insufficient corrosion resistance and mechanical strength, can lead to tray damage, increasing maintenance costs, and potentially causing safety incidents. Utility Model Content

[0004] In order to make up for the deficiencies of the prior art, the embodiments of the present application provide a urea synthesis tower, thereby solving the problems of low efficiency and inconvenience in use of the existing urea synthesis tower.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a urea synthesis tower, comprising an outer shell, an inner partition plate having a diameter smaller than the inner diameter of the outer shell being provided inside the outer shell, a pair of symmetrically distributed heat exchange devices being provided inside the inner partition plate, a reaction structure being connected above the heat exchange device via a gas pipe, the reaction structure comprising a plurality of evenly distributed tower plates placed inside the inner partition plate, a plurality of densely distributed small-diameter gas phase holes penetrating the tower plates being connected to the tower plates via evenly distributed corrugated grooves, and the tower plates being connected via staggered downcomers.

[0006] Preferably: the outer shell is covered with a protective shell, one side of the protective shell is provided with an air inlet that passes through itself and the outer shell, the end of the reaction structure away from the heat exchange device is connected to an exhaust bin through an air pipe, and the top of the exhaust bin is provided with an air outlet that passes through itself and the outer shell.

[0007] Preferably: there is a certain gap between the diameter of the exhaust bin and the internal partition plate, and a pair of inner shells close to itself are provided below the exhaust bin, and the other end of the inner shell is provided with a transverse partition plate fixedly connected to the internal partition plate, and the transverse partition plate is provided with a connecting pipe that passes through itself and is inserted into the heat exchange device.

[0008] Preferably: the heat exchange device includes a pair of symmetrically distributed reaction chambers partially penetrated by connecting pipes, and the reaction chambers are connected to sealing plugs corresponding to the connecting pipes through connecting holes penetrating their own plate bodies. The sealing plugs and connecting holes correspond to and connect the connecting pipes and the reaction chambers, and a thermal reaction structure is provided inside the reaction chambers.

[0009] Preferably, the tower plate is one of a sieve plate, a float valve plate, and a bubble cap plate; a blocking ring partially penetrated by a downcomer is provided on the outside of the tower plate; an end of the blocking ring away from the tower plate is connected to a liquid infusion pipe corresponding to itself through an overflow weir; and liquid inlets and outlets penetrating itself, the internal partition plate, the outer shell and the protective shell are provided at the upper and lower ends of the inner shell.

[0010] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0011] The utility model divides the interior of the outer shell, i.e., the tower body, into two spaces by arranging an internal partition plate placed inside the outer shell. When the gas enters the tower body, it enters the interior of the internal partition plate along the reserved air channel. In this process, not only is the heat exchange device preliminarily heating the gas, but the heat exchange device is also cooled down once. When the gas enters the heat exchange device in the internal partition plate and is heated, the gas rises due to the heat, and then enters the reaction structure through the gas pipe. The gas continues to rise through the tower plate and enters the liquid phase. The gas in the liquid phase is in the form of bubbles. As the gas rises, it fully contacts the liquid, promoting the mixing and reaction of the reactants. Some gas will pass through the liquid layer and enter the liquid phase of the upper tray to continue participating in the reaction. In this process, the corrugated grooves on the tray form a corrugated structure. Compared with traditional sieve plate trays, the corrugated tray can more effectively separate gas and liquid, improve gas-liquid contact efficiency, and at the same time, by reducing the diameter of the gas phase holes and the diameter of the bubbles, the specific surface area of gas-liquid contact is increased, thereby improving the heat and mass transfer efficiency between the gas and liquid phases. The appropriate increase in the open area makes the gas phase distribution more uniform, which is conducive to intensifying the reaction. At the same time, considering the special position of the first tray, the open area is increased to facilitate the uniform distribution of the gas phase, acting as a gas distributor.

[0012] Other advantages, objectives and features of the present invention will be described in part in the following description and will be apparent to those skilled in the art based on an examination of the following or may be learned from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a three-dimensional schematic diagram of a urea synthesis tower of the utility model;

[0014] Figure 2 This is a cross-sectional view of a urea synthesis tower of the present utility model;

[0015] Figure 3 This is a cross-sectional view of a heat exchange device for a urea synthesis tower according to the present invention;

[0016] Figure 4 This is a cross-sectional view of the reaction structure of a urea synthesis tower of the present invention;

[0017] Figure 5 The utility model is a cross-sectional view of a barrier ring of a urea synthesis tower.

[0018] As shown in the figure:

[0019] 1. Outer shell;

[0020] 11. Internal partition plate; 12. Heat exchange device; 13. Gas pipe; 14. Protective shell; 15. Air inlet; 16. Exhaust chamber; 17. Air outlet; 18. Horizontal partition plate; 19. Connecting pipe;

[0021] 121. Reaction chamber; 122. Connection hole; 123. Sealing plug; 124. Thermal reaction structure;

[0022] 2. Reaction structure;

[0023] 21. Tower tray; 22. Corrugated groove; 23. Gas phase hole; 24. Downcomer; 25. Inner shell; 26. Baffle ring; 27. Overflow weir; 28. Liquid transfer pipe; 29. Liquid inlet and outlet. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] It should be noted that the terms “vertical”, “horizontal”, “up”, “down”, “left”, “right” and similar expressions used in this document are for illustrative purposes only and do not represent the only implementation method.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains; the terms used herein in the specification of this invention are for the purpose of describing specific embodiments only and are not intended to limit this invention; the term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0027] like Figure 1 and Figure 2 As shown, a urea synthesis tower includes an outer shell 1, an inner partition plate 11 with a diameter smaller than the inner diameter of the outer shell 1 is provided inside the outer shell 1, and a protective shell 14 is provided on the outside of the outer shell 1. One side of the protective shell 14 is provided with an air inlet 15 that penetrates the protective shell 14 and the outer shell 1. The end of the reaction structure 2 away from the heat exchange device 12 is connected to an exhaust bin 16 through an air pipe 13, and an air outlet 17 that penetrates the outer shell 1 and the outer shell 1 is provided above the exhaust bin 16. A pair of symmetrically distributed heat exchange devices 12 are provided inside the inner partition plate 11, and the heat exchange device 12 is connected to the reaction structure 2 above through the air pipe 13. The reaction structure 2 includes a plurality of evenly distributed tower plates 21 placed inside the inner partition plate 11. The tower plates 21 are connected to a plurality of densely distributed small-diameter gas phase holes 23 that penetrate the tower plates 21 through evenly distributed corrugated grooves 22. The tower plates 21 are connected by staggered downcomers 24.

[0028] In this embodiment, an internal partition plate 11 is provided inside the outer shell 1, thereby dividing the interior of the outer shell 1, i.e., the tower body, into two spaces. When the gas enters the tower body, it enters the interior of the internal partition plate 11 along the reserved gas channel. In this process, not only is the heat exchange device 12 initially heating the gas, but the heat exchange device 12 is also cooled once. When the gas enters the heat exchange device 12 in the internal partition plate 11 and is heated, the gas is heated and rises, thereby entering the reaction structure 2 through the gas pipe 13 below the reaction structure 2. The gas continues to rise through the tower plate 21 and enters the liquid phase. The gas in the liquid phase The gas rises in the form of bubbles, fully contacting the liquid and promoting the mixing and reaction of reactants such as ammonia and carbon dioxide. Some gas will pass through the liquid layer and enter the liquid phase of the upper tray 21 to continue participating in the reaction. During this process, the corrugated grooves 22 on the tray 21 give the tray 21 a corrugated structure. Compared with traditional sieve plate trays, the corrugated tray can more effectively separate gas and liquid, improving gas-liquid contact efficiency. At the same time, by reducing the diameter of the gas phase holes 23, the diameter of the bubbles is reduced to increase the specific surface area of gas-liquid contact, thereby improving the heat and mass transfer efficiency between the gas and liquid phases. Appropriately increasing the porosity makes the gas phase more evenly distributed, which is conducive to intensifying the reaction. At the same time, considering the special position of the first tray 21, the porosity is increased to facilitate the uniform distribution of the gas phase, acting as a gas distributor.

[0029] like Figure 3 、 4 As shown in FIG5 , there is a certain gap between the diameter of the exhaust bin 16 and the internal partition plate 11. A pair of inner shells 25 close to the exhaust bin 16 are provided below the exhaust bin 16. The other end of the inner shell 25 is provided with a transverse partition plate 18 fixedly connected to the internal partition plate 11. The transverse partition plate 18 is provided with a connecting pipe 19 that penetrates itself and is inserted into the heat exchange device 12. The heat exchange device 12 includes a pair of symmetrically distributed reaction bins 121 partially penetrated by the connecting pipe 19. The reaction bin 121 is connected to a sealing member corresponding to the connecting pipe 19 through a connecting hole 122 that penetrates its own plate body. The sealing plug 123 corresponds to the connecting hole 122 and is connected to the connecting pipe 19 and the reaction chamber 121. A thermal reaction structure 124 is provided inside the reaction chamber 121. The tower plate 21 is one of a sieve plate, a float valve plate, and a bubble plate. The outside of the tower plate 21 is provided with a blocking ring 26 partially penetrated by the downcomer 24. The end of the blocking ring 26 away from the tower plate 21 is connected to a liquid infusion pipe 28 corresponding to itself through an overflow weir 27. The upper and lower ends of the inner shell 25 are provided with liquid inlet and outlet ports 29 that penetrate itself, the internal partition plate 11, the outer shell 1 and the protective shell 14.

[0030] In this embodiment, the internal partition plate 11 divides the interior of the tower body into two spaces, providing space for the preliminary heating of the gas and the cooling of the heat exchange device, thereby optimizing the heat exchange process; the gas is preliminarily heated by the heat exchange device 12, thereby increasing the temperature of the gas, which is beneficial to promoting the progress of the urea synthesis reaction. The setting of the heat exchange device also helps to control and regulate the temperature in the tower, ensuring that the reaction is carried out at an appropriate temperature; compared with the traditional sieve plate tower tray, the design of the corrugated grooves 22 and the gas phase holes 23 on the tower tray 21 of the present application can more effectively carry out gas-liquid diversion, improve the gas-liquid contact efficiency, reduce the diameter of the gas phase holes, and reduce the diameter of the bubbles to increase the specific surface area of the gas-liquid contact, thereby improving the heat and mass transfer efficiency between the gas and liquid phases; appropriately increasing the opening rate makes the gas phase distribution more uniform, which is beneficial to strengthening the reaction, and the first layer of the tower tray Taking the special position into consideration, the opening rate is increased to facilitate the uniform distribution of the gas phase, which plays the role of a gas distributor; the exhaust bin 16 and the inner shell 25 ensure the effective collection and discharge of the gas, and the setting of the inner shell contributes to the stability and safety of the structure in the tower; the reaction bin 121 and the thermal reaction structure 124 provide suitable space and conditions for the urea synthesis reaction, which helps to improve the reaction efficiency and conversion rate; the blocking ring 26 and the liquid infusion pipe 28 contribute to the uniform distribution and flow of the liquid between the tower plates, reduce the back mixing phenomenon, and improve the reaction efficiency; the liquid inlet and outlet 29 facilitates the introduction and discharge of the liquid, contributes to the circulation and renewal of the liquid in the tower, and ensures the continuity and efficiency of the reaction; the protective shell 14 provides additional protection for the tower body, helps to prevent the influence of the external environment on the reaction in the tower, and also enhances the mechanical strength and durability of the tower body.

[0031] When using:

[0032] 1. Preparation before startup:

[0033] Check whether all components of the urea synthesis tower are installed correctly, including the tower tray, heat exchange device, exhaust bin, inner shell, etc.

[0034] Ensure the sealing of protective shells, liquid inlets and outlets, sealing plugs and other components to prevent gas and liquid leakage.

[0035] Check whether the connections of gas pipes, connecting pipes, infusion pipes and other pipelines are firm to ensure there are no leaks.

[0036] 2. Preheating and pretreatment:

[0037] Start the heat exchange device to preliminarily heat the gas entering the tower body to increase the temperature of the gas and promote the urea synthesis reaction.

[0038] Adjust the temperature of the heat exchange device to ensure that the gas enters the reaction structure at an appropriate temperature.

[0039] 3. Gas introduction:

[0040] Open the air inlet and introduce the gas containing ammonia and carbon dioxide into the tower.

[0041] The gas enters the interior of the internal partition plate along the reserved air channel and is preliminarily heated by the heat exchange device.

[0042] 4. Gas reaction:

[0043] The heated gas enters the reaction structure through the gas pipeline and passes through the tower tray into the liquid phase.

[0044] The gas rises in the liquid phase in the form of bubbles, fully contacts the liquid, and promotes the mixing and reaction of ammonia and carbon dioxide.

[0045] 5. Gas-liquid mass transfer:

[0046] The corrugated grooves and gas phase holes on the tray enable effective diversion of the gas and liquid phases, thereby improving the gas-liquid contact efficiency.

[0047] Reduce the diameter of the gas phase pores, increase the specific surface area of gas-liquid contact, and improve the heat and mass transfer efficiency.

[0048] 6. Liquid circulation and renewal:

[0049] Liquid is introduced and discharged through the liquid inlet and outlet to ensure the circulation and renewal of the liquid in the tower.

[0050] The barrier ring and liquid infusion pipe design ensure the uniform distribution and flow of liquid between the tower plates.

[0051] 7. Collection of reaction products:

[0052] The urea solution generated by the reaction is collected through the liquid outlet at the bottom of the tower.

[0053] Unreacted gases and steam are collected through the exhaust silo and outlet.

[0054] 8. Temperature and pressure control:

[0055] Monitor the temperature and pressure in the tower to ensure that the reaction proceeds under appropriate conditions.

[0056] By adjusting the heat exchange device and pressure control device, the temperature and pressure in the tower are maintained stable.

[0057] 9. Security Monitoring:

[0058] Regularly check the operating status of the tower and all components to ensure safe operation.

[0059] Monitor safety devices such as safety valves, pressure gauges, thermometers, etc. to ensure timely response in abnormal situations.

[0060] 10. Shutdown and maintenance:

[0061] After the production cycle is completed, the air inlet and liquid outlet are closed, and the heat exchange device and pressure control device are stopped.

[0062] Carry out regular maintenance and cleaning of the urea synthesis tower, check the wear of components such as the tower plate, heat exchange device, and exhaust bin, and replace them when necessary.

[0063] In summary, the design of the urea synthesis tower device improves the efficiency and safety of urea synthesis, while also enhancing the stability and durability of the device through innovation and optimization of structures such as the internal partition plate, heat exchange device, corrugated groove and gas phase hole, open area ratio optimization, exhaust chamber and inner shell, reaction chamber and thermal reaction structure, barrier ring and liquid infusion pipe, liquid inlet and outlet, and protective shell.

[0064] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this technology may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A urea synthesis tower, comprising an outer shell (1), characterized in that: The outer shell (1) is provided with an inner partition plate (11) having a diameter smaller than the outer shell's inner diameter. A pair of symmetrically distributed heat exchange devices (12) are provided inside the inner partition plate (11). A reaction structure (2) is connected above the heat exchange device (12) via a gas pipe (13). The reaction structure (2) comprises a plurality of evenly distributed tower plates (21) disposed inside the inner partition plate (11). The tower plates (21) are connected to a plurality of densely distributed small-diameter gas phase holes (23) penetrating the tower plates (21) via evenly distributed corrugated grooves (22). The tower plates (21) are connected to each other via staggered downcomers (24).

2. A urea synthesis tower according to claim 1, characterized in that: The outer shell (1) is covered with a protective shell (14), and one side of the protective shell (14) is provided with an air inlet (15) that passes through the protective shell (14) and the outer shell (1). The end of the reaction structure (2) away from the heat exchange device (12) is connected to an exhaust bin (16) through an air pipe (13), and an air outlet (17) that passes through the exhaust bin (16) and the outer shell (1) is provided above the exhaust bin (16).

3. A urea synthesis tower according to claim 2, characterized in that: A certain gap is left between the diameters of the exhaust bin (16) and the internal partition plate (11). A pair of inner shells (25) close to the exhaust bin (16) are provided below the exhaust bin (16). The other end of the inner shell (25) is provided with a transverse partition plate (18) fixedly connected to the internal partition plate (11). The transverse partition plate (18) is provided with a connecting pipe (19) that passes through the transverse partition plate and is inserted into the heat exchange device (12).

4. A urea synthesis tower according to claim 3, characterized in that: The heat exchange device (12) comprises a pair of symmetrically distributed reaction chambers (121) partially penetrated by a connecting pipe (19); a sealing plug (123) corresponding to the connecting pipe (19) is connected to the reaction chamber (121) through a connecting hole (122) penetrating the plate body thereof; the sealing plug (123) and the connecting hole (122) correspond to and communicate with the connecting pipe (19) and the reaction chamber (121); and a thermal reaction structure (124) is provided inside the reaction chamber (121).

5. A urea synthesis tower according to claim 1, characterized in that: The tower tray (21) is one of a sieve plate, a float valve plate, and a bubble cap plate. The outside of the tower tray (21) is provided with a blocking ring (26) partially penetrated by the downcomer (24). The end of the blocking ring (26) away from the tower tray (21) is connected to a liquid delivery pipe (28) corresponding to the blocking ring via an overflow weir (27). The inner shell (25) is provided with liquid inlet and outlet ports (29) penetrating the inner shell, the internal partition plate (11), the outer shell (1), and the protective shell (14) at the upper and lower ends.

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