Urea hydrolysis ammonia preparation reaction device

Abstract

The utility model relates to the field of ammonia production equipment, in particular to a urea hydrolysis ammonia production reaction device which comprises a reaction tank, a urea solution inlet pipe fixedly communicated with the top of the side end of the reaction tank, a blow-off pipe fixedly communicated with the bottom of the side end of the reaction tank, and a steam heating assembly arranged in the reaction tank. A stirring assembly used for improving the heating efficiency of a urea solution is further arranged in the reaction tank, and an ammonia gas conveying assembly is fixedly communicated with the top of the reaction tank. The urea solution heating device has the beneficial effects that the urea solution can be effectively stirred in the heating process of the urea solution, so that the heating efficiency of steam to the urea solution is effectively improved, and the heating efficiency of the urea solution is improved. Therefore, the urea hydrolysis ammonia preparation efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of ammonia production equipment, in particular to a urea hydrolysis ammonia production reaction device. Background Art

[0002] At present, there are three types of reducing agents for SCR denitrification systems: liquid ammonia, ammonia water and urea. Liquid ammonia is the most harmful, and the harmfulness of ammonia water is between liquid ammonia and urea. Although ammonia water is safer than liquid ammonia, its transportation cost is much higher than that of liquid ammonia. The disadvantages of using ammonia water are: because ammonia water contains water, the transportation cost and the volume of the storage tank are increased; the water must be evaporated before the SCR reaction, and evaporating ammonia water consumes about 10 times more energy than evaporating liquid ammonia; the ammonia water system requires a liquid pump, and for the same amount of reducing agent, ammonia water requires about 4 to 5 times the storage space, resulting in increased costs. Unless there is a stable source of ammonia water near the power plant, general power plants will not choose ammonia water as a reducing agent for SCR denitrification. Urea is a non-toxic and harmless solid particle that is safe and convenient to transport and store, and is harmless to the environment. According to the "Design Code for Large and Medium-sized Thermal Power Plants" (GB50660-2011), power plants located in large and medium-sized cities and suburbs should choose urea as a reducing agent. The Technical Code for Flue Gas Denitrification Design of Thermal Power Plants (DL / T 5480-2013) stipulates that power plants located in large and medium-sized cities and suburban areas should choose urea as the reducing agent.

[0003] At present, the urea hydrolysis reaction step of producing ammonia is usually that a urea solution with a concentration of about 40% to 60% is transported to a hydrolysis reactor, and heating steam enters the hydrolysis reactor through a coil. The heating steam does not mix with the urea solution and refluxes through the coil. The condensed water is recovered to the drain tank. The pressure of the gas-liquid two-phase equilibrium system of the urea solution in the hydrolysis reactor is about 0.5MPa to 0.6MPa, and the temperature is about 120°C to 155°C. For a 50wt% (wt% is the mass concentration) urea solution feed, the ammonia-containing gas flow generated in the hydrolysis reactor contains about 37.5wt% ammonia, 18.7wt% carbon dioxide and 43.8wt% water vapor. These ammonia-containing gas flows first enter the metering module, then are mixed with the heated dilution air, and finally enter the SCR reactor for reaction to remove NOx in the flue gas.

[0004] Although the current urea hydrolysis to ammonia reaction device can heat the urea solution through steam very well, it has the disadvantage of low heating efficiency and needs further improvement.

[0005] Therefore, it is necessary to invent a urea hydrolysis ammonia production reaction device. Utility Model Content

[0006] To this end, the utility model provides a urea hydrolysis ammonia production reaction device to solve the problems raised in the above background technology.

[0007] In order to achieve the above-mentioned purpose, the utility model provides the following technical solutions: a urea hydrolysis ammonia production reaction device, comprising a reaction tank, a urea solution inlet pipe is fixedly connected to the top of the side end of the reaction tank, a sewage pipe is fixedly connected to the bottom of the side end of the reaction tank, and also comprises a steam heating component, the steam heating component is arranged in the reaction tank, the reaction tank is also provided with a stirring component for improving the heating efficiency of the urea solution, and the top of the reaction tank is fixedly connected to an ammonia delivery component.

[0008] Preferably, the steam heating component comprises a steam inlet pipe, the steam inlet pipe passes through the bottom of the side end of the reaction tank, and the other end of the steam inlet pipe is fixedly connected to a steam pipe.

[0009] Preferably, the steam heating component also includes a heating coil, which is arranged at the lower part of the reaction tank, the end of the steam inlet pipe is fixedly connected to the bottom end of the heating coil, and a steam outlet pipe is fixed to the top of the heating coil, and the steam outlet pipe passes through the side end of the reaction tank.

[0010] Preferably, a condensate drain pipe is fixedly connected to the bottom of the heating coil, the bottom end of the condensate drain pipe passes through the bottom of the reaction tank, and a steam trap is provided on the body of the condensate drain pipe.

[0011] Preferably, the stirring assembly includes a vertically arranged cylinder, the bottom end of the cylinder is fixed to the top of the reaction tank, a lifting plate is fixed to the top of the cylinder output shaft, a reducer is fixed to the bottom of the lifting plate, a stirring motor is vertically fixed to the top of the lifting plate, the stirring motor output shaft is fixedly connected to the reducer input shaft, and a rotating shaft is vertically fixed to the bottom end of the reducer output shaft.

[0012] Preferably, the bottom end of the rotating shaft vertically passes through the center of the top of the reaction tank, a sealing sleeve is provided between the surface of the rotating shaft and the top of the reaction tank, and a stirring paddle is fixed to the bottom end of the rotating shaft, and the stirring paddle is located inside the heating coil.

[0013] Preferably, the ammonia delivery component includes a blower, the bottom of which is fixed to the top of the reaction tank, the input end of the blower is fixedly connected to an air supply pipe, the bottom end of the air supply pipe vertically penetrates into the reaction tank, the top of the reaction tank is fixedly connected to an air supply pipe, and the air supply pipe body is provided with a flow meter.

[0014] Preferably, the ammonia delivery component also includes a fresh air fan, an air inlet hood is fixed at the input end of the fresh air fan, a dust screen is fixed inside the air inlet hood, a heating pipe is connected to the output pipe of the fresh air fan, an electric heating wire is built into the heating pipe, a connecting pipe is fixedly connected to the top of the heating pipe, the connecting pipe is fixedly connected to the gas pipe, and the end of the gas pipe away from the reaction tank is connected to the SCR reactor.

[0015] The beneficial effect of the utility model is that through the coordinated use of the reaction tank, urea solution inlet pipe, sewage pipe, steam heating component, stirring component and ammonia delivery component, the urea solution can be effectively stirred during the heating process of the urea solution, thereby effectively improving the heating efficiency of the urea solution by steam, which is beneficial to improving the efficiency of urea hydrolysis to produce ammonia. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A structural cross-sectional view provided by the utility model;

[0017] Figure 2 for Figure 1 A magnified view of the structure at A;

[0018] Figure 3 A structural stereogram of the heating coil provided by the utility model;

[0019] Figure 4 This is a front view of the structure provided by the utility model.

[0020] In the figure: 1. reaction tank; 2. urea solution inlet pipe; 3. drain pipe; 4. steam inlet pipe; 5. steam pipe; 6. heating coil; 7. steam outlet pipe; 8. condensate drain pipe; 9. steam trap; 10. cylinder; 11. lifting plate; 12. reducer; 13. stirring motor; 14. rotating shaft; 15. sealing sleeve; 16. stirring paddle; 17. air blower; 18. air supply pipe; 19. air transmission pipe; 20. flow meter; 21. fresh air blower; 22. air inlet hood; 23. dust screen; 24. heating pipe; 25. electric heating wire; 26. connecting pipe. DETAILED DESCRIPTION

[0021] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0022] Please refer to the attached Figure 1-4The utility model provides a urea hydrolysis ammonia production reaction device, comprising a reaction tank 1, a urea solution inlet pipe 2 is fixedly connected to the top of the side end of the reaction tank 1, and is used to add a urea solution of a configured concentration into the reaction tank 1 through the urea solution inlet pipe 2, and a sewage pipe 3 is fixedly connected to the bottom of the side end of the reaction tank 1, and is used to discharge waste water after the reaction. It should be noted that the urea solution inlet pipe 1 and the sewage pipe 3 are both provided with corresponding stop valves, and also include a steam heating component, which is arranged in the reaction tank 1. The reaction tank 1 is also provided with a stirring component for improving the heating efficiency of the urea solution, and the top of the reaction tank 1 is fixedly connected to an ammonia delivery component;

[0023] The steam heating assembly includes a steam inlet pipe 4, which passes through the bottom of the side end of the reaction tank 1. The other end of the steam inlet pipe 4 is fixedly connected with a steam pipe 5. It should be noted that the body of the steam pipe 5 is provided with a corresponding stop valve. The steam heating assembly also includes a heating coil 6, which is arranged at the lower part of the inside of the reaction tank 1. The end of the steam inlet pipe 4 is fixedly connected with the bottom end of the heating coil 6. A steam outlet pipe 7 is fixed at the top of the heating coil 6. The steam outlet pipe 7 passes through the side end of the reaction tank 1. Specifically, steam can be transported through the steam pipe 5, then enter the heating coil 6 through the steam inlet pipe 4, and then be discharged from the steam outlet pipe 7, thereby realizing the operation of heating and hydrolyzing the urea solution added to the reaction tank 1 to produce ammonia;

[0024] The bottom of the heating coil 6 is fixedly connected with a condensate drain pipe 8, the bottom end of which passes through the bottom of the reaction tank 1, and the body of the condensate drain pipe 8 is provided with a steam trap 9 for discharging steam condensate from the heating coil 6;

[0025] The stirring assembly includes a vertically arranged cylinder 10, the bottom end of the cylinder 10 is fixed to the top of the reaction tank 1, a lifting plate 11 is fixed to the top of the output shaft of the cylinder 10, and a reducer 12 is fixed to the bottom of the lifting plate 11. It should be noted that the reducer is a transmission device for low speed and high torque. The power of the electric motor, internal combustion engine or other high-speed operation is meshed with a large gear on the output shaft through a gear with a small number of teeth on the input shaft of the reducer to achieve the purpose of deceleration. A stirring motor 13 is vertically fixed to the top of the lifting plate 11, and the output shaft of the stirring motor 13 is fixedly connected to the input shaft of the reducer 12. A rotating shaft 14 is vertically fixed to the bottom end of the output shaft of the reducer 12. The bottom end of the rotating shaft 14 vertically penetrates the center of the top of the reaction tank 1, and the surface of the rotating shaft 14 is connected to the top of the reaction tank 1. A sealing sleeve 15 is arranged between the rotating shaft 14, which can play a sealing function to prevent ammonia leakage. A stirring paddle 16 is fixed to the bottom end of the rotating shaft 14, and the stirring paddle 16 is located on the inner side of the heating coil 6. Specifically, under the deceleration effect of the reducer 12, when the stirring motor 13 is running, the stirring paddle 16 can be driven by the rotating shaft 14 to slowly rotate in the reaction tank 1, so that the urea solution in the reaction tank 1 can be stirred, and when the cylinder 10 is running, the lifting plate 11 can be controlled to rise and fall, so as to control the rotating stirring paddle 16 to realize the function of rotating and lifting in the reaction tank 1, that is, the device can effectively stir the urea solution during the heating process of the urea solution, thereby effectively improving the heating efficiency of the urea solution by steam, which is beneficial to improving the efficiency of urea hydrolysis to produce ammonia;

[0026] The ammonia delivery assembly includes a blower 17, the bottom of which is fixed on the top of the reaction tank 1, the input end of the blower 17 is fixedly connected with an air supply pipe 18, the bottom end of the air supply pipe 18 vertically penetrates into the reaction tank 1, the top of the reaction tank 1 is fixedly connected with an air delivery pipe 19, and the air delivery pipe 19 is provided with a flow meter 20. Specifically, the ammonia produced by heating and hydrolyzing the urea solution can be blown out by the running blower 17, and then metered and delivered through the air delivery pipe 19;

[0027] The ammonia delivery assembly also includes a fresh air fan 21. An air inlet hood 22 is fixed at the input end of the fresh air fan 21. A dustproof net 23 is fixed inside the air inlet hood 22 for discharging dust and other impurities in the air. A heating pipe 24 is connected to the output end pipeline of the fresh air fan 21. The heating pipe 24 has an electric heating wire 25 built in it. The electric heating wire 25 can generate the required heat energy when energized, thereby heating the fresh air generated by the fresh air fan 21. A connecting pipe 26 is fixedly connected to the top of the heating pipe 24. The connecting pipe 26 is fixedly connected to the gas pipe 19. The end of the gas pipe 19 away from the reaction tank 1 is connected to the SCR reactor (not shown in the figure), that is, the ammonia delivered through the gas pipe 19 is mixed with the heated dilution air, and finally enters the SCR reactor for reaction to remove NOx in the flue gas. It should be noted that the SCR reactor is a well-known technology for those skilled in the art and will not be described in detail.

[0028] It should be noted that the device is electrically connected to an external main controller and 220V mains electricity, and the main controller can be a computer or other prior art equipment for control.

[0029] The use process of the utility model is as follows: the user first adds the urea solution of the configured concentration into the reaction tank 1 through the urea solution inlet pipe 2, and then controls the steam pipe 5 to transport the required steam into the heating coil 6, so as to realize the heating and hydrolysis of the urea solution added to the reaction tank 1 to produce ammonia. In the heating process, the user can turn on the cylinder 10 and the stirring motor 13. Under the deceleration effect of the reducer 12, when the stirring motor 13 is running, the stirring paddle 16 can be driven by the rotating shaft 14 to slowly rotate in the reaction tank 1, so as to stir the urea solution in the reaction tank 1. When the cylinder 10 is running, the lifting plate 11 can be controlled to rise and fall, so as to control the rotating stirring. The paddle 16 can realize the function of rotating and lifting in the reaction tank 1, that is, the device can effectively stir the urea solution during the heating of the urea solution, thereby effectively improving the heating efficiency of the steam on the urea solution, which is beneficial to improving the efficiency of urea hydrolysis to produce ammonia. The user can also turn on the blower 17 in advance, so that the ammonia produced by heating and hydrolyzing the urea solution can be blown out by the running blower 17, and then measured and transported through the gas pipe 19. When the flow meter 20 detects the flow rate, the user turns on the fresh air fan 21 and the electric heating wire 25, so that the ammonia transported through the gas pipe 19 is mixed with the heated dilution air, and finally enters the SCR reactor for reaction to remove NOx in the flue gas.

[0030] The above is only a preferred embodiment of the utility model. Any person skilled in the art can modify the utility model by using the above technical solution or modify it into an equivalent technical solution. Therefore, any simple modification or equivalent replacement based on the technical solution of the utility model shall fall within the scope of protection claimed by the utility model.

Claims

1. A urea hydrolysis ammonia production reaction device, comprising a reaction tank (1), a urea solution inlet pipe (2) is fixedly connected to the top of the side end of the reaction tank (1), and a sewage discharge pipe (3) is fixedly connected to the bottom of the side end of the reaction tank (1), characterized in that: It also comprises a steam heating component, which is arranged in the reaction tank (1). The reaction tank (1) is also provided with a stirring component for improving the heating efficiency of the urea solution. The top of the reaction tank (1) is fixedly connected to an ammonia delivery component.

2. The urea hydrolysis to ammonia reaction device according to claim 1, characterized in that: The steam heating component comprises a steam inlet pipe (4), the steam inlet pipe (4) passes through the bottom of the side end of the reaction tank (1), and the other end of the steam inlet pipe (4) is fixedly connected to a steam pipe (5).

3. The urea hydrolysis to ammonia reaction device according to claim 2, characterized in that: The steam heating assembly further comprises a heating coil (6), wherein the heating coil (6) is arranged at the lower part of the interior of the reaction tank (1), the end of the steam inlet pipe (4) is fixedly connected to the bottom end of the heating coil (6), and a steam outlet pipe (7) is fixed at the top end of the heating coil (6), and the steam outlet pipe (7) passes through the side end of the reaction tank (1).

4. The urea hydrolysis to ammonia reaction device according to claim 3, characterized in that: The bottom of the heating coil (6) is fixedly connected to a condensate drain pipe (8), the bottom end of the condensate drain pipe (8) passes through the bottom of the reaction tank (1), and the body of the condensate drain pipe (8) is provided with a steam trap (9).

5. The urea hydrolysis to ammonia reaction device according to claim 3, characterized in that: The stirring assembly comprises a vertically arranged cylinder (10), the bottom end of the cylinder (10) is fixed to the top of the reaction tank (1), a lifting plate (11) is fixed to the top of the output shaft of the cylinder (10), a reducer (12) is fixed to the bottom of the lifting plate (11), a stirring motor (13) is vertically fixed to the top of the lifting plate (11), the output shaft of the stirring motor (13) is fixedly connected to the input shaft of the reducer (12), and a rotating shaft (14) is vertically fixed to the bottom end of the output shaft of the reducer (12).

6. The urea hydrolysis to ammonia reaction device according to claim 5, characterized in that: The bottom end of the rotating shaft (14) vertically passes through the center of the top of the reaction tank (1), a sealing sleeve (15) is provided between the surface of the rotating shaft (14) and the top of the reaction tank (1), and a stirring paddle (16) is fixed to the bottom end of the rotating shaft (14), and the stirring paddle (16) is located on the inner side of the heating coil (6).

7. The urea hydrolysis to ammonia reaction device according to claim 1, characterized in that: The ammonia gas delivery assembly comprises a blower (17), the bottom of the blower (17) is fixed to the top of the reaction tank (1), the input end of the blower (17) is fixedly connected to an air supply pipe (18), the bottom end of the air supply pipe (18) vertically penetrates into the reaction tank (1), the top of the reaction tank (1) is fixedly connected to an air supply pipe (19), and the air supply pipe (19) is provided with a flow meter (20).

8. The urea hydrolysis to ammonia reaction device according to claim 7, characterized in that: The ammonia delivery assembly further comprises a fresh air blower (21), an air inlet hood (22) being fixed at the input end of the fresh air blower (21), a dust screen (23) being fixed inside the air inlet hood (22), a heating pipe (24) being connected to the output end pipeline of the fresh air blower (21), an electric heating wire (25) being built into the heating pipe (24), a connecting pipe (26) being fixedly connected at the top end of the heating pipe (24), the connecting pipe (26) being fixedly connected to the gas delivery pipe (19), and an end of the gas delivery pipe (19) away from the reaction tank (1) being connected to the SCR reactor.

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