Reactor for preparing ammonia through urea hydrolysis with zoned temperature control

Abstract

The utility model discloses a zone temperature control urea hydrolysis ammonia preparation reactor, which belongs to the technical field of urea hydrolysis ammonia preparation, and comprises a urea hydrolyzer body, a plurality of partition plates are arranged in the urea hydrolyzer body, and the partition plates divide the internal space of the urea hydrolyzer body into a plurality of zones; the plurality of liquid inlet assemblies are arranged on the urea hydrolyzer body; the plurality of heaters are arranged in the urea hydrolyzer body; the pressure relief mechanism is connected with the urea hydrolyzer body. According to the urea hydrolyzer disclosed by the utility model, the interior of the urea hydrolyzer body is divided into a plurality of reaction areas by the partition plates, and each reaction area is internally provided with an independent heater, so that the technical problems of crystallization and corrosion of pipelines, valves and the like caused by water vapor condensation after the load of the urea hydrolyzer is reduced are solved, each reaction area is independently heated, and the service life of the urea hydrolyzer is prolonged. And water vapor condensation is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of preparing ammonia by hydrolyzing urea, in particular to a zoned temperature-controlled urea hydrolyzing ammonia reactor. Background Art

[0002] The urea hydrolysis reactor is relatively large, and its volume is usually twice the liquid phase reaction volume. The liquid phase reaction volume is designed according to the amount of ammonia required for denitrification under the BMCR working condition (maximum continuous evaporation of the boiler) of the power plant. However, during the deep peak regulation period of the coal-fired power plant, its minimum can be reduced to below 20%. At this time, the output of the urea hydrolyzer will also decrease, but the urea hydrolyzer usually maintains a stable operating liquid level, so the output level is mainly reduced by reducing the reaction temperature. Under normal operation, the operating temperature in the urea hydrolyzer is 150-160℃ and the pressure is about 0.6MPa. After the load is reduced, the output level needs to be reduced, so the urea hydrolyzer temperature drops to 130℃ or lower, but the pressure still needs to be maintained at about 0.6MPa. At this time, the temperature of the product gas is lower than the saturation temperature under the corresponding partial pressure, which will cause the water vapor in the product gas to condense, and then ammonia and carbon dioxide dissolve in water to generate ammonium carbamate, or cause ammonium carbamate crystallization and corrosion in equipment, pipelines and valves, etc., which is not conducive to the reliable operation of the urea hydrolysis ammonia production system. Utility Model Content

[0003] In order to solve the above problems, the utility model provides a zoned temperature-controlled urea hydrolysis ammonia production reactor, comprising:

[0004] A urea hydrolyzer body, wherein the urea hydrolyzer body is used to input a urea solution to perform an ammonia production reaction, wherein a plurality of partitions are arranged inside the urea hydrolyzer body, and the plurality of partitions divide the internal space of the urea hydrolyzer body into a plurality of regions, each of which is a separate reaction zone, and the top of the urea hydrolyzer body is a connected space;

[0005] A plurality of liquid inlet components, wherein the plurality of liquid inlet components are arranged on the urea hydrolyzer body, and each of the liquid inlet components is adapted to each of the reaction zones;

[0006] Wherein, each of the liquid inlet components is provided with a first pressure gauge, and the first pressure gauge monitors the pressure in the liquid inlet component to monitor the pressure in the urea hydrolyzer body;

[0007] A plurality of heaters, wherein the plurality of heaters are disposed in the urea hydrolyzer body, and each of the heaters is adapted to each of the reaction zones, so that each heater can heat the urea solution in each reaction zone;

[0008] A pressure relief mechanism is connected to the urea hydrolyzer body so that the internal pressure of the urea hydrolyzer body can be regulated by the pressure relief mechanism during the ammonia production reaction.

[0009] Optionally, the liquid inlet component further includes:

[0010] A liquid inlet pipeline, the liquid inlet pipeline is connected to the urea hydrolyzer body, and the liquid inlet pipeline corresponds to the reaction zone;

[0011] An inlet valve is arranged on the liquid inlet pipeline. The opening and closing degree of the inlet valve can adjust the flow rate of the urea solution in the liquid inlet pipeline. The inlet valve is a normally open valve.

[0012] Optionally, the pressure relief mechanism includes:

[0013] A product gas pipeline, the product gas pipeline is connected to the urea hydrolyzer body, and the product gas pipeline is used to discharge the product gas in the urea hydrolyzer body;

[0014] A product gas valve, which is disposed on the product gas pipeline and controls the flow of product gas in the product gas pipeline by opening or closing the product gas valve;

[0015] A second pressure gauge, the second pressure gauge is arranged on the product gas pipeline, and the second pressure gauge is used to monitor the pressure of the gas flowing into the product gas pipeline;

[0016] A second thermometer is provided on the product gas pipeline, and is used to measure the temperature of the product gas.

[0017] Optionally, the product gas pipeline further includes a branch pipe, wherein the branch pipe is further provided with a gas phase pressure relief valve, and the gas phase pressure relief valve is electrically connected to the first pressure gauge.

[0018] Optionally, a plurality of liquid level gauges are further provided on the urea hydrolyzer body, and each of the liquid level gauges is adapted to each of the reaction zones.

[0019] Optionally, a plurality of drain valves are further provided on the urea hydrolyzer body, and each of the drain valves is adapted to each of the reaction zones.

[0020] Optionally, a plurality of first thermometers are further provided on the urea hydrolyzer body, and each of the first thermometers is adapted to each of the reaction zones.

[0021] Optionally, a safety valve is also provided on the urea hydrolyzer body.

[0022] By adopting the above technical solution, the utility model mainly has the following technical effects:

[0023] The utility model divides the interior of a urea hydrolyzer body into a plurality of reaction zones by arranging a partition, and each reaction zone is provided with an independent heater, thereby solving the technical problem that water vapor condenses after the load of the urea hydrolyzer is reduced, causing crystallization and corrosion of pipes and valves, etc., and achieving the technical effect of individually heating each reaction zone to prevent water vapor condensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of a urea hydrolysis and ammonia production reactor with zoned temperature control according to the utility model;

[0025] Figure 2 This is a schematic diagram of the partial structure of a urea hydrolysis reactor with zoned temperature control in the utility model. Figure 1 ;

[0026] Figure 3 This is a schematic diagram of the partial structure of a urea hydrolysis reactor with zoned temperature control in the utility model. Figure 2 .

[0027] The meanings of the reference numerals are as follows:

[0028] 1. Urea hydrolyzer body; 11. Partition plate; 12. Reaction zone; 13. Liquid level gauge; 14. Drain valve; 15. First thermometer; 16. Safety valve;

[0029] 2. Liquid inlet assembly; 21. First pressure gauge; 22. Liquid inlet pipeline; 23. Inlet valve;

[0030] 3. Heater;

[0031] 4. Pressure relief mechanism; 41. Product gas pipeline; 411. Branch pipe; 412. Gas phase pressure relief valve; 42. Product gas valve; 43. Second pressure gauge; 44. Second thermometer. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the specification of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0034] Example

[0035] See also Figure 1-Figure 3 The utility model provides a zoned temperature-controlled urea hydrolysis ammonia production reactor. In practical application, in order to prevent the product gas temperature from being lower than the saturation temperature under the corresponding partial pressure, so that the water vapor in the product gas condenses and crystallizes, and then causes blockage and corrosion of equipment, pipelines, etc., the utility model comprises a urea hydrolyzer body 1, a plurality of liquid inlet components 2 connected to the urea hydrolyzer body 1, a plurality of heaters 3 connected to the urea hydrolyzer body 1, and a pressure relief mechanism 4 connected to the urea hydrolyzer body 1.

[0036] Specifically, the urea hydrolyzer body 1 is used to react the urea solution to produce ammonia. Preferably, the urea hydrolyzer body 1 can be made of stainless steel. A plurality of partitions 11 are arranged inside the urea hydrolyzer body 1. The plurality of partitions 11 are parallel to each other and fixedly assembled at the bottom of the urea hydrolyzer body 1. The height of the partitions 11 is higher than the center height of the urea hydrolyzer body 1, so that the plurality of partitions 11 divide the bottom space in the urea hydrolyzer body 1 into a plurality of regions, each of which is a separate ammonia production reaction zone 12, so that the urea solution is stored and ammonia is produced in the reaction zone 12, and the top space in the urea hydrolyzer body 1 is still a gas phase space, so that the ammonia produced in each reaction zone 12 can flow in a gas phase space. Preferably, the partition 11 can be made of a polymer material such as polytetrafluoroethylene.

[0037] A plurality of the liquid inlet assemblies 2 are arranged on the urea hydrolyzer body 1, and each of the liquid inlet assemblies 2 is adapted to each of the reaction zones 12, that is, each of the liquid inlet assemblies 2 is connected to each of the reaction zones 12 of the urea hydrolyzer body 1, so that the urea solution flows into each of the reaction zones 12 through the liquid inlet assemblies 2. Wherein, each of the liquid inlet assemblies 2 is provided with a first pressure gauge 21, and the first pressure gauge 21 monitors the pressure in the urea hydrolyzer body 1 connected to the liquid inlet assemblies 2 by monitoring the pressure in the liquid inlet assemblies 2. By installing the pressure gauge on the liquid inlet assemblies 2, the fluid pressure in the liquid inlet assemblies 2 is measured. However, since the liquid inlet assemblies 2 are connected to the urea hydrolyzer body 1, the pressure in the liquid inlet assemblies 2 is equal to the pressure inside the urea hydrolyzer body 1, and therefore, the pressure measured by the first pressure gauge 21 is the pressure in the urea hydrolyzer body 1.

[0038] The plurality of heaters 3 are all arranged in the urea hydrolyzer body 1, and each of the heaters 3 is adapted to each of the reaction zones 12, that is, the plurality of heaters 3 are independent heating components, and each heater 3 can heat the urea solution in each reaction zone 12 separately. Among them, the urea hydrolyzer body 1 is also provided with a plurality of first thermometers 15, and each of the first thermometers 15 is adapted to each of the reaction zones 12, and the temperature in each reaction zone 12 in the urea hydrolyzer body 1 can be monitored by the first thermometer 15, so that the staff can adjust the heating power of the heater 3 according to the temperature displayed by the first thermometer 15, and adjust the temperature of the solution in each reaction zone 12 to the desired range. Preferably, the heater 3 can be an electric heating component made of titanium alloy.

[0039] The pressure relief mechanism 4 is connected to the urea hydrolyzer body 1, so that during the ammonia production reaction, the product gas can be released and the internal pressure of the urea hydrolyzer body 1 can be regulated through the pressure relief mechanism 4, ensuring that the pressure inside the urea hydrolyzer body 1 is maintained within a stable range.

[0040] In this embodiment, the number of reaction zones 12 to be operated in the urea hydrolyzer body 1 can be selected according to the amount of ammonia required for denitration. For example, under the condition of the maximum continuous evaporation amount of the boiler, the urea solution flows into each reaction zone 12 of the urea hydrolyzer body 1 through the liquid inlet assembly 2. When the urea solution in each reaction zone 12 reaches the set value, the heater 3 is added to each reaction zone 12 and the heater 3 is operated. At this time, the product gas after the hydrolysis of the urea solution is discharged through the pressure relief mechanism 4. When the product gas is discharged, the pressure in the urea hydrolyzer body 1 is monitored by the first pressure gauge 21 to ensure that the pressure in the urea hydrolyzer body 1 is maintained within a certain range (such as 0.6 MPa); when the amount of ammonia required for denitration decreases, the liquid inlet assembly 2 corresponding to some reaction zones 12 is closed, and the corresponding heater 3 is closed at the same time, wherein the reaction zone 12 that is not stopped continues to maintain the inflow of urea solution, and the urea hydrolysis operation is continuously performed in the reaction zone 12 that is not stopped, and the heater 3 is kept continuously heated to prevent the urea temperature from decreasing. Since the number of working reaction zones 12 can be adjusted, after reducing the output level of the hydrolyzer, the temperature of the urea solution in the reaction zone 12 participating in the reaction in the urea hydrolyzer body 1 can always be maintained within a certain range (e.g., 150-160°C), and the temperature of the product gas can also be maintained above a corresponding temperature (e.g., 150°C). At this time, the temperature of the water vapor in the product gas is always higher than the saturation temperature under the corresponding partial pressure, so condensation will not occur, thereby preventing ammonia and carbon dioxide in the product gas from dissolving in water and reacting to form ammonium carbamate, thereby avoiding blockage and corrosion of pipelines caused by the formation of ammonium carbamate crystals.

[0041] In some preferred embodiments, in order to facilitate viewing of the liquid level of the urea solution put into each partition, the urea hydrolyzer body 1 is further provided with a plurality of liquid level gauges 13, and each of the liquid level gauges 13 is adapted to each of the reaction zones 12, that is, the liquid level of the urea solution in each reaction zone 12 can be observed through the liquid level gauge 13. The urea hydrolyzer body 1 is further provided with a plurality of thermometers 15, and each of the thermometers 15 is adapted to each of the reaction zones 12, so that the staff can monitor the temperature in each reaction zone 12 through each thermometer 15.

[0042] In this embodiment, for the convenience of describing the liquid inlet assembly 2, one liquid inlet assembly 2 is used for description, and the liquid inlet assembly 2 includes a liquid inlet pipe 22 and an inlet valve 23. The liquid inlet pipe 22 is connected to the reaction zone 12 in the urea hydrolyzer body 1, so that the urea solution flows into the reaction zone 12 through the liquid inlet pipe 22. The inlet valve 23 is arranged on the liquid inlet pipe 22, and the opening and closing degree of the inlet valve 23 can adjust the flow rate of the urea solution in the liquid inlet pipe 22. Because the reaction will continue during the urea hydrolysis process, the urea solution needs to continue to flow into the reaction zone 12, and the inlet valve 23 is a normally open valve.

[0043] In this embodiment, the pressure relief mechanism 4 includes a product gas pipeline 41, a product gas valve 42, a second pressure gauge 43 and a second thermometer 44. The product gas pipeline 41 is connected to the urea hydrolyzer body 1, and the product gas pipeline 41 is used to discharge the product gas in the urea hydrolyzer body 1. The product gas pipeline 41 further includes a branch pipe 411, which is used to share the pressure relief pressure of the product gas pipeline 41, so as to prevent the internal pressure of the product gas pipeline 41 from being too high. A gas phase pressure relief valve 412 is also provided on the branch pipe 411, and the gas phase pressure relief valve 412 is electrically connected to the first pressure gauge 21. For example, when any one of the first pressure gauges 21 detects that the pressure in the urea hydrolyzer body 1 exceeds a preset pressure (such as 0.9 MPa), the gas phase pressure relief valve 412 can be opened through an external control module, so that the branch pipe 411 and the product gas pipeline 41 are simultaneously exhausted and pressure relieved. After the pressure in the urea hydrolyzer body 1 drops to a certain range (such as 0.6 MPa), the gas phase pressure relief valve 412 can be closed to prevent the branch pipe 411 from continuing to exhaust. The product gas valve 42 is arranged on the product gas pipeline 41, and the product gas valve 42 can control the flow state of the product gas in the product gas pipeline 41 by opening or closing; the second pressure gauge 43 is arranged on the product gas pipeline 41, and the second pressure gauge 43 is used to monitor the gas pressure flowing into the product gas pipeline 41, so that the staff can check and make real-time adjustments; the second thermometer 44 is arranged on the product gas pipeline 41, and the second thermometer 44 is used to measure the temperature of the product gas.

[0044] In some preferred embodiments, a safety valve 16 is further provided on the urea hydrolyzer body 1, and the safety valve 16 is used to further discharge the pressure in the urea hydrolyzer body 1. For example, when any pressure gauge monitors that the pressure is greater than the safety threshold (such as 1.2 MPa), the gas phase pressure relief valve 412 and the safety valve 16 are opened at the same time. At this time, the product gas pipeline 41, the branch pipe 411 and the safety valve 16 can all discharge the pressure to achieve a faster discharge of the pressure in the urea hydrolyzer body 1. After the pressure drops to a certain range (such as 0.6 MPa), the gas phase pressure relief valve 412 and the safety valve 16 are closed, and each reaction zone 12 continues to operate.

[0045] In some preferred embodiments, a plurality of drain valves 14 are further provided at the bottom end of the urea hydrolyzer body 1 , and each drain valve 14 is connected to each reaction zone 12 , so that the wastewater generated in each reaction zone 12 can be discharged by opening the drain valve 14 .

[0046] Finally, it should be noted that the embodiments of the present invention disclose only preferred embodiments of the present invention, which are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A zone temperature-controlled urea hydrolysis reactor for ammonia production, characterized in that: include: A urea hydrolyzer body (1), the urea hydrolyzer body (1) being used to input a urea solution to carry out an ammonia production reaction, wherein a plurality of partitions (11) are arranged inside the urea hydrolyzer body (1), and the plurality of partitions (11) divide the internal space of the urea hydrolyzer body (1) into a plurality of regions connected at the top, each region being a separate reaction zone (12); A plurality of liquid inlet components (2), wherein the plurality of liquid inlet components (2) are all arranged on the urea hydrolyzer body (1), and each of the liquid inlet components (2) is adapted to each of the reaction zones (12); Wherein, each of the liquid inlet components (2) is provided with a first pressure gauge (21), and the first pressure gauge (21) monitors the pressure in the liquid inlet component (2) and thus monitors the pressure in the urea hydrolyzer body (1) connected to the liquid inlet component (2); A plurality of heaters (3), wherein the plurality of heaters (3) are all arranged in the urea hydrolyzer body (1), and each of the heaters (3) is adapted to each of the reaction zones (12); A pressure relief mechanism (4), the pressure relief mechanism (4) being connected to the urea hydrolyzer body (1) and being used for adjusting the internal pressure of the urea hydrolyzer body (1) during the ammonia production reaction.

2. The urea hydrolysis reactor for producing ammonia with zoned temperature control according to claim 1, characterized in that: The liquid inlet component (2) further comprises: A liquid inlet pipeline (22), the liquid inlet pipeline (22) being connected to the reaction zone (12) in the urea hydrolyzer body (1); An inlet valve (23), wherein the inlet valve (23) is arranged on the liquid inlet pipeline (22), and the inlet valve (23) adjusts the flow rate of the urea solution in the liquid inlet pipeline (22) according to the degree of opening and closing, and the inlet valve (23) is a normally open valve.

3. The zoned temperature-controlled urea hydrolysis reactor for producing ammonia according to claim 1, characterized in that: The pressure relief mechanism (4) comprises: A product gas pipeline (41), the product gas pipeline (41) being in communication with the urea hydrolyzer body (1), the product gas pipeline (41) being used to discharge the product gas in the urea hydrolyzer body (1); a product gas valve (42), the product gas valve (42) being arranged on the product gas pipeline (41), the product gas valve (42) being used to adjust the flow state of the product gas pipeline (41); a second pressure gauge (43), the second pressure gauge (43) being arranged on the product gas pipeline (41), the second pressure gauge (43) being used to monitor the pressure of the gas flowing into the product gas pipeline (41); A second thermometer (44), the second thermometer (44) is arranged on the product gas pipeline (41), and the second thermometer (44) is used to measure the temperature of the product gas.

4. The zoned temperature-controlled urea hydrolysis reactor for producing ammonia according to claim 3, characterized in that: The product gas pipeline (41) further comprises a branch pipe (411) for sharing gas pressure, wherein a gas phase pressure relief valve (412) is also provided on the branch pipe (411), and the gas phase pressure relief valve (412) is electrically connected to the first pressure gauge (21).

5. The zoned temperature-controlled urea hydrolysis reactor for producing ammonia according to claim 1, characterized in that: The urea hydrolyzer body (1) is also provided with a plurality of liquid level gauges (13), each of the liquid level gauges (13) being adapted to each of the reaction zones (12) and being used to monitor the liquid level in each of the reaction zones (12).

6. The zoned temperature-controlled urea hydrolysis reactor for producing ammonia according to claim 1, characterized in that: A plurality of drain valves (14) are also provided at the bottom end of the urea hydrolyzer body (1), and each of the drain valves (14) is connected to each of the reaction zones (12).

7. The zoned temperature-controlled urea hydrolysis reactor for producing ammonia according to claim 1, characterized in that: The urea hydrolyzer body (1) is also provided with a plurality of first thermometers (15), and each of the first thermometers (15) is adapted to each of the reaction zones (12) and is used to monitor the temperature in each of the reaction zones (12).

8. The zoned temperature-controlled urea hydrolysis reactor for producing ammonia according to claim 1, characterized in that: The urea hydrolyzer body (1) is also provided with a safety valve (16) for further adjusting the internal pressure of the urea hydrolyzer body (1).

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