A urea hydrolysis ammonia production system with compressed air dynamic corrosion prevention and mass transfer synergistic reinforcement

Abstract

This invention discloses a urea hydrolysis ammonia production system with dynamic corrosion prevention and synergistic mass transfer enhancement using compressed air. The system includes a urea hydrolysis reactor, a heating coil, a dynamic eddy current generator, a microbubble generator, an air compressor, a compressed air storage tank, an air filter, an air heater, and a condensate tank. The dynamic eddy current generator is installed between the inner wall of the urea hydrolysis reactor and the heating coil. The microbubble generators are arranged in a semi-circular array around the heating coil. A nanoscale vapor-induced passivation film is formed on the inner wall of the urea hydrolysis reactor, and a metallic compound coating is sprayed onto the outer surface of the heating coil. The beneficial effects of this invention are: the dynamic eddy current generator and the microbubble generator work synergistically to enhance the disturbance at the mass transfer interface, increasing the urea hydrolysis reaction rate; the passivation film reduces the corrosion rate of the urea hydrolysis reactor, improving the stability and reliability of the urea hydrolysis system; and the metallic coating improves the wear and corrosion resistance and thermal conductivity of the heating coil, reducing energy consumption and operating costs.

Description

Technical Field

[0001] This utility model relates to the field of atmospheric pollution control technology, specifically a urea hydrolysis ammonia production system with dynamic anti-corrosion and synergistic enhancement of mass transfer using compressed air. Background Technology

[0002] The main methods for producing ammonia from urea are urea pyrolysis and urea hydrolysis. Urea pyrolysis ammonia production technology suffers from high operating costs, while urea hydrolysis is increasingly popular due to its low energy consumption, safety, and stability. Currently, the main method for producing ammonia from flue gas denitrification is urea hydrolysis. The heat source is typically steam, which is not mixed with the urea solution. Drainage is returned to the condensate tank via heating coils.

[0003] Traditional urea hydrolysis reactors have the following problems:

[0004] 1. The urea hydrolysis reactor contains urea solution and byproducts such as ammonium carbamate and biuret, which are highly corrosive. The inner wall of the urea hydrolysis reactor and the heating coil are easily corroded and damaged, resulting in frequent equipment maintenance and replacement, which seriously affects the continuity and stability of production.

[0005] 2. The urea solution is heated unevenly on the surface of the heating coil, resulting in a large local temperature gradient, low mass transfer efficiency, and low efficiency of urea hydrolysis reaction.

[0006] 3. The urea hydrolysis reactor has high steam consumption and energy consumption, and the thermal conductivity of the heating coil needs to be improved.

[0007] Therefore, providing a urea hydrolysis reactor with strong corrosion resistance, high mass transfer efficiency and low energy consumption is of great significance for improving production efficiency and achieving energy conservation and emission reduction goals, and has become an urgent problem to be solved by those skilled in the art. Utility Model Content

[0008] To address the shortcomings of existing technologies and considering the characteristics of urea hydrolysis ammonia production systems, this invention proposes a urea hydrolysis ammonia production system with dynamic corrosion protection and enhanced mass transfer via compressed air. This system reduces the corrosion rate of the urea hydrolysis reactor, enhances gas-liquid mass transfer efficiency, improves the wear and corrosion resistance of the heating coil, increases the thermal conductivity of the heating coil, and reduces energy consumption and operating costs.

[0009] This utility model provides the following technical solution: a urea hydrolysis ammonia production system with dynamic anti-corrosion and synergistic mass transfer enhancement using compressed air, characterized in that it includes a urea hydrolysis reactor, a heating coil, a dynamic eddy current generator, a microbubble generator, an air compressor, a compressed air storage tank, an air filter, an air heater, and a condensate tank.

[0010] The urea hydrolysis reactor includes a heating steam inlet located at the top of a steam tube box, a heating coil located inside the urea hydrolysis reactor, and a steam condensate outlet located at the bottom of the steam tube box. The heating steam inlet is connected to the heating coil, and the heating coil is connected to the steam condensate outlet.

[0011] The steam condensate outlet is connected to the heat source inlet of the air heater via a pipeline, and the heat source outlet of the air heater is connected to the inlet of the condensate tank via a pipeline; the cold source inlet of the air heater is connected to the outlet of the air filter via a pipeline, and the cold source outlet of the air heater is connected to the compressed air inlet via a pipeline; the compressed air inlet is connected to a microbubble generator installed inside the urea hydrolysis reactor.

[0012] The air compressor outlet is connected to the compressed air storage tank inlet via a pipeline, and the compressed air storage tank outlet is connected to the air filter inlet via a pipeline;

[0013] A dynamic vortex generator is provided between the inner wall of the urea hydrolysis reactor and the heating coil, and a flow guide hole is provided on the dynamic vortex generator;

[0014] The outer surface of the heating coil is coated with a wear-resistant and corrosion-resistant metallic compound coating.

[0015] Preferably, the vortex plate of the dynamic vortex generator is driven by a servo motor, which automatically adjusts the angle of the vortex plate to form an adaptive vortex field; the vortex plate is provided with honeycomb-shaped guide holes.

[0016] Preferably, the microbubble generator is arranged in a semi-circular array around the heating coil inside the urea hydrolysis reactor, and the microbubble generator adopts a microporous ceramic structure with the nozzle facing the heating coil.

[0017] Preferably, the compressed air enters the urea hydrolysis reactor via a microbubble generator, forming a nanoscale gas-phase induced passivation film on the inner wall of the urea hydrolysis reactor.

[0018] Preferably, the heating coil is made of 316L material and its outer surface is coated with silicon carbide, tungsten carbide and titanium carbide coatings.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] (1) The urea hydrolysis ammonia production system of the present invention, which is a synergistic mass transfer enhancement system for dynamic anti-corrosion of compressed air, is provided between the inner wall of the urea hydrolysis reactor and the heating coil. A dynamic vortex generator is set between the inner wall of the urea hydrolysis reactor and the heating coil. The angle of the vortex plate is automatically adjusted by a servo motor to adapt to the mass transfer requirements under different working conditions. Multiple vortex plates are stacked to form a continuously changing gradient flow field. Microbubble generators are arranged in a semi-circular array around the heating coil, with the nozzles facing the heating coil. The dynamic vortex generator and the microbubble generator work together to enhance the disturbance of the mass transfer interface, improve the urea hydrolysis reaction rate, and avoid local deposition and crystallization of urea particles and impurities.

[0021] (2) The urea hydrolysis ammonia production system of the present invention is a dynamic anti-corrosion and mass transfer enhancement system of compressed air. Compressed air enters the urea hydrolysis reactor through a microbubble generator with microporous ceramic structure. A nanoscale gas phase induced passivation film is formed on the inner wall of the urea hydrolysis reactor, which reduces the corrosion rate of the urea hydrolysis reactor, reduces the frequency of equipment maintenance and replacement, and improves the stability and reliability of the urea hydrolysis system production.

[0022] (3) The urea hydrolysis ammonia production system with dynamic anti-corrosion and synergistic enhancement of mass transfer by compressed air described in this utility model is coated with silicon carbide (SiC), tungsten carbide (WC) or titanium carbide (TiC) coating on the outer surface of the heating tube in contact with the urea solution, which improves the wear and corrosion resistance of the heating coil, increases the thermal conductivity of the heating coil, and reduces energy consumption and operating costs. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the urea hydrolysis ammonia production system with dynamic anti-corrosion and synergistic mass transfer enhancement using compressed air, as described in this utility model.

[0025] In the diagram: 1-Urea hydrolysis reactor, 2-Heating steam inlet, 3-Heating coil, 4-Steam condensate outlet, 5-Dynamic vortex generator, 6-Compressed air inlet, 7-Microbubble generator, 8-Urea solution inlet, 9-Ammonia product gas outlet, 10-Air compressor, 11-Compressed air storage tank, 12-Filter, 13-Air heater, 14-Condensate tank. Detailed Implementation

[0026] To make the objectives, technical features, and advantages of this utility model clearer, specific embodiments of this utility model are now described with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0027] The structure, principle, and working process of this utility model will be further explained below with reference to the embodiments.

[0028] like Figure 1 As shown, this utility model provides a urea hydrolysis ammonia production system with dynamic corrosion prevention and synergistic mass transfer enhancement using compressed air, including a urea hydrolysis reactor, a heating coil, a dynamic eddy current generator, a microbubble generator, an air compressor, a compressed air storage tank, an air filter, an air heater, and a condensate tank.

[0029] Heating steam at a temperature of 160~200℃ and a pressure of 0.6~1.0MPa enters the heating coil of the urea hydrolysis reactor through the steam inlet. The steam condensate enters the heat source inlet of the air heater, utilizing the residual heat of the condensate to heat compressed air. This prevents compressed air from entering the urea hydrolysis reactor, which would lower the temperature of the urea solution and affect the normal progress of the urea hydrolysis reaction. The cooled steam condensate is collected in a condensate tank and is primarily used for preparing the urea solution.

[0030] Compressed air, heated by an air heater, enters a microbubble generator arranged in a semi-circular array around the heating coil inside the urea hydrolysis reactor. The microbubble generator uses a microporous ceramic structure, with the nozzle facing the heating coil, forming microbubbles with a diameter of 0.05mm to 0.2mm.

[0031] A dynamic vortex generator is installed between the inner wall of the urea hydrolysis reactor and the heating coil. The vortex plate is driven by a servo motor. Through sensors and an intelligent control system, parameters such as urea solution concentration, temperature, and flow rate are monitored in real time, and the angle of the vortex plate is automatically adjusted to form an adaptive vortex field. The tilt angle of the vortex plate is dynamically adjustable from 0° to 60°. The vortex plate is equipped with honeycomb-shaped flow guide holes with a diameter of 5mm to 8mm and an opening ratio of 10% to 40%. This breaks the fixed flow field limitation of traditional static baffles and realizes dynamic optimization of fluid shear force and mixing efficiency to adapt to the mass transfer requirements under different working conditions. Through the superposition of multiple vortex plates, a continuously changing gradient flow field is formed, which avoids the local deposition and crystallization of urea particles and impurities.

[0032] The dynamic eddy current generator and the microbubble generator work together to enhance the disturbance of the gas-liquid mass transfer interface, improve the mass transfer efficiency by more than 40%, and increase the urea hydrolysis reaction rate by 20%.

[0033] Compressed air enters the urea hydrolysis reactor via a microbubble generator, forming a nanoscale gas-phase induced passivation film on the inner wall of the reactor, protecting the metal surface of the hydrolysis reactor and reducing the corrosion rate by 80%.

[0034] The heating coil is made of 316L stainless steel, with a silicon carbide (SiC), tungsten carbide (WC), or titanium carbide (TiC) coating applied to the outer surface of the heating coil where it contacts the urea solution. The coating thickness is 50-100 μm. High bonding strength is achieved through plasma spraying and flame spraying processes, increasing the thermal conductivity of the heating coil by 30% and significantly reducing steam consumption. The coating hardness reaches HV1500 or higher, improving wear and corrosion resistance by 3 times, significantly reducing wear and corrosion of the heating coil caused by the strong disturbance of the urea solution.

[0035] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A urea hydrolysis ammonia production system with dynamic corrosion prevention and synergistic mass transfer enhancement using compressed air, characterized in that: It includes a urea hydrolysis reactor (1), a heating coil (3), a dynamic eddy current generator (5), a microbubble generator (7), an air compressor (10), a compressed air storage tank (11), an air filter (12), an air heater (13), and a condensate tank (14). The urea hydrolysis reactor (1) includes a heating steam inlet (2) located at the top of the steam tube box, a heating coil (3) located inside the urea hydrolysis reactor (1), and a steam condensate outlet (4) located at the bottom of the steam tube box. The heating steam inlet (2) is connected to the heating coil (3), and the heating coil (3) is connected to the steam condensate outlet (4). The steam condensate outlet (4) is connected to the heat source inlet of the air heater (13) through a pipeline, and the heat source outlet of the air heater (13) is connected to the inlet of the condensate tank (14) through a pipeline; the cold source inlet of the air heater (13) is connected to the outlet of the air filter (12) through a pipeline, and the cold source outlet of the air heater (13) is connected to the compressed air inlet (6) through a pipeline; the compressed air inlet (6) is connected to the microbubble generator (7) installed inside the urea hydrolysis reactor (1); The outlet of the air compressor (10) is connected to the inlet of the compressed air storage tank (11) through a pipeline, and the outlet of the compressed air storage tank (11) is connected to the inlet of the air filter (12) through a pipeline; A dynamic vortex generator (5) is provided between the inner wall of the urea hydrolysis reactor (1) and the heating coil (3), and a flow guide hole is provided on the dynamic vortex generator (5). The outer surface of the heating coil (3) is coated with a wear-resistant and corrosion-resistant metal compound coating.

2. The urea hydrolysis ammonia production system with dynamic corrosion prevention and synergistic mass transfer enhancement using compressed air as described in claim 1, characterized in that: The dynamic vortex generator (5) has a vortex plate driven by a servo motor, which automatically adjusts the angle of the vortex plate to form an adaptive vortex field; the vortex plate is provided with honeycomb-shaped guide holes.

3. The urea hydrolysis ammonia production system with dynamic corrosion prevention and synergistic mass transfer enhancement using compressed air as described in claim 1, characterized in that: The microbubble generator (7) is arranged in a semi-circular array around the heating coil (3) inside the urea hydrolysis reactor (1). The microbubble generator (7) adopts a microporous ceramic structure and the nozzle faces the heating coil (3).

4. The urea hydrolysis ammonia production system with dynamic corrosion prevention and synergistic mass transfer enhancement using compressed air as described in claim 1, characterized in that: The compressed air enters the urea hydrolysis reactor (1) via the microbubble generator (7) and forms a nanoscale gas-phase induced passivation film on the inner wall of the urea hydrolysis reactor (1).

5. The urea hydrolysis ammonia production system with dynamic corrosion prevention and synergistic mass transfer enhancement using compressed air as described in claim 1, characterized in that: The heating coil (3) is made of 316L material and its outer surface is coated with silicon carbide, tungsten carbide and titanium carbide.

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