Ammonia synthesis reaction water circulation system

Abstract

The present invention discloses an ammonia synthesis reaction water circulation system, including a combustion furnace, a boiler, an acid-making device and a makeup water pump. The boiler includes: a furnace body, the top of the furnace body is integrally connected with a furnace top, the furnace top is in a conical shape protruding outward, and the top of the conical shape is interconnected with an outlet main pipe, and a water inlet pipe is arranged at the bottom of the furnace body; a heat exchange pipe, the heat exchange pipe is in a spring pipe shape and is horizontally disposed in the inner cavity of the furnace body, an air outlet hole is opened at the top of the end of the heat exchange pipe, the height of the air outlet hole is higher than the drainage liquid level of the furnace body, and the aperture of the air outlet hole is smaller than the inner diameter of the heat exchange pipe. The ammonia synthesis reaction water circulation system of the present invention not only has high heat exchange efficiency, but also can realize the automatic circulation function of the condensed water accumulated on the inner bottom wall of the heat exchange pipe, reducing the waste of water resources.

Description

Technical Field

[0001] The present invention belongs to the technical field of ammonia synthesis, and particularly relates to an ammonia synthesis reaction water circulation system. Background Art

[0002] Synthetic ammonia refers to ammonia directly synthesized from nitrogen and hydrogen in the presence of high temperature, high pressure and a catalyst, and is a basic inorganic chemical process. In modern chemical industry, ammonia is the main raw material for the fertilizer industry and basic organic chemical industry.

[0003] In the reaction process of the ammonia synthesis chemical process, the desulfurization and decarbonization device will generate acidic gas containing H2S. If directly discharged, it will not only pollute the environment, but also cause waste of resources. In the prior art, corresponding treatment and reuse can convert the acidic gas containing H2S; the process is as Figure 1 shown. The acidic gas containing H2S generated by the desulfurization and decarbonization device is first transported to a combustion furnace, and overoxygen combustion is used. After high-temperature incineration, high-temperature steam containing SO2 is sent to a boiler (the reaction principle of overoxygen combustion is: 2H2S + 3O2 → 2SO2 + 2H2O + reaction heat). After the boiler recovers the heat, the heat is used to heat the circulating water. Finally, the SO2 gas and hot water are sent to a dry-process acid-making device to produce industrial product H2SO4 (dry-process acid-making principle: 2SO2 + O2 → 2SO3, SO3 + H2O (hot) → H2SO4). Finally, the remaining water flows back to the boiler for reheating, thereby forming a water cycle, achieving comprehensive utilization of resources while avoiding environmental pollution.

[0004] In the prior art, the principle of the heat recovery boiler for high-temperature steam containing SO2 is as Figure 2 and Figure 3 shown, including: a housing body, an annular inner tank, an inlet pipe, an outlet pipe, an inlet water pipe and an outlet water pipe. A circular water cavity for accommodating water is formed between the inner wall of the housing body and the outer wall of the annular inner tank. The high-temperature steam containing SO2 enters the inner cavity of the annular inner tank from the inlet pipe and finally exits from the outlet pipe at the top. The heat carried by the high-temperature steam containing SO2 heats the water in the circular water cavity; it has the following disadvantages: 1. The heat exchange efficiency is low; 2. After heat exchange, the condensed water drips along the inner wall of the annular inner tank to the bottom of the annular inner tank, making it difficult to reuse. Summary of the Invention

[0005] In view of the problems in the prior art, the present invention proposes the following technical solutions:

[0006] An ammonia synthesis reaction water circulation system, including a combustion furnace, a boiler, an acid-making device and a make-up water pump. The boiler includes:

[0007] A furnace body, the top of the furnace body is integrally connected with a furnace top. The furnace top is in a conical shape protruding outward, and the top of the conical shape is interconnected with a main outlet pipe. The bottom of the furnace body is provided with an inlet water pipe;

[0008] A heat exchange pipe, the heat exchange pipe is in the shape of a spring pipe and is horizontally placed across the inner cavity of the furnace body. An air outlet hole is opened at the top of the end of the heat exchange pipe. The height of the air outlet hole is higher than the drainage liquid level of the furnace body, and the aperture of the air outlet hole is smaller than the inner diameter of the heat exchange pipe;

[0009] The SO2 and hot steam formed after the combustion furnace burns acidic gas enter the inner cavity of the furnace body through the heat exchange pipe. The spring pipe-shaped heat exchange pipe in the inner cavity of the furnace body increases the heat exchange between the hot steam and the circulating water in the furnace body. After heat exchange, the gas overflows upward from the air outlet hole and is finally transported to the acid-making device through the air outlet main pipe.

[0010] As a preference of the above technical solution, a heat exchange component is fixedly connected to the inner walls of the furnace body and the furnace top. The heat exchange component includes a bottom plate fixedly connected to the inner wall of the furnace body. A heat exchange plate is fixedly connected to the top of the bottom plate. The heat exchange plate is arc-shaped, and the concave surface of the arc shape of one of the heat exchange plates is located above the air outlet hole.

[0011] As a preference of the above technical solution, side plates are integrally and fixedly connected to both sides of the heat exchange plate, and the side plates extend downward along the radian of the heat exchange plate from the top of the heat exchange plate.

[0012] As a preference of the above technical solution, a water outlet pipe is interconnected on the side wall of the furnace body, and the water outlet pipe is flush with the drainage liquid level of the inner cavity of the furnace body.

[0013] As a preference of the above technical solution, a pressure-adaptive drainage mechanism is arranged at the bottom of the heat exchange pipe, and the pressure-adaptive drainage mechanism extends into the inner cavity of the water inlet pipe.

[0014] As a preference of the above technical solution, the pressure-adaptive drainage mechanism includes a communicating pipe that is interconnected with the bottom of the heat exchange pipe, and the bottom of the communicating pipe is fixedly inserted into the water inlet pipe. A communicating hole is opened on the side wall of the communicating pipe, and a pressure-dependent drainage component is arranged inside the communicating pipe.

[0015] As a preference of the above technical solution, the communicating pipe is in the shape of a round outside and square inside, and the outer diameter of the communicating pipe is smaller than the inner diameter of the water inlet pipe.

[0016] As a preference of the above technical solution, the pressure-dependent drainage component includes a piston in the inner cavity of the communicating pipe. A Y-shaped communicating cavity is opened inside the piston. A first magnetic attraction block is fixedly connected to the inner wall of the communicating pipe. A second magnetic attraction block is fixedly connected in an embedded manner at the top of the piston, and the second magnetic attraction block faces the first magnetic attraction block. A spring is fixedly connected between the piston and the inner wall of the bottom of the communicating pipe.

[0017] As a preference of the above technical solution, a lower abutting block is fixedly connected to the inner wall of the communicating pipe, and the lower abutting block is located below the communicating hole.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. Cold circulating water is replenished into the boiler of the present invention through the water inlet pipe, so that a certain height of circulating water is always maintained in the inner cavity of the furnace. The drainage liquid level is lower than the height of the air outlet hole, but the heat exchange pipes are immersed in the circulating water by no less than 90%. The high-temperature hot steam containing SO2 enters the inner cavity of the furnace through the heat exchange pipes. The heat exchange pipes located in the inner cavity of the furnace are in the shape of horizontally placed spring pipes. Therefore, compared with the straight cylindrical channels in the prior art, the heat exchange pipes in the shape of spring pipes can have more sufficient contact with the circulating water, increasing the path and time of the high-temperature hot steam containing SO2 in the pipes, and thus greatly improving the heat transfer efficiency.

[0020] 2. In the present invention, due to the increase in the path and time of the high-temperature hot steam containing SO2 in the pipes by the heat exchange pipes in the shape of spring pipes, the heat steam undergoes better heat transfer and heat consumption, and the moisture in the heat steam can be better condensed into water droplets, greatly reducing the water content in the SO2 gas and reducing the burden of subsequent SO2 gas purification. Further, the arc-shaped heat exchange plate is provided to further contact the remaining heat steam in the buffer cavity, and condenses into water droplets on the surface of the heat exchange plate and flows into the circulating water along the heat exchange plate, not only further increasing the heat transfer efficiency, but also further reducing the water content in the SO2 gas. The arc-shaped concave surface of one heat exchange plate is located above the air outlet hole, which can prevent the splashing of the condensed water discharged from the air outlet hole, so that it can flow into the circulating water along the arc-shaped concave surface of the heat exchange plate. By setting the bottom plate, the contact area between the side surface of the heat exchange plate and the buffer cavity can be further increased, further increasing the heat transfer efficiency and reducing the water content in the SO2 gas.

[0021] 3. After the high-temperature hot steam containing SO2 entering the inner pipe of the heat exchange pipe exchanges heat with the circulating water, the moisture in the heat steam will condense into water droplets and flow along the inner wall of the heat exchange pipe to the bottom. In one round of the conveying stage, in the initial stage (0 - t1) and the attenuation stage (t2 - t3), the air pressure in the inner cavity of the heat exchange pipe is less than P. At this time, as Figure 8 shown, the second magnetic attraction block and the first magnetic attraction block are adsorbed to each other, and the spring is in a compressed state, providing an upward elastic force for the piston. At this time, the Y-shaped communication cavity and the communication hole are not connected. When in the peak stage (t1 - t2), when the air pressure in the inner cavity of the heat exchange pipe is greater than P, the air pressure is greater than the sum of the magnetic attraction forces of the first magnetic attraction block and the second magnetic attraction block + the elastic force of the spring. At this time, the piston is pushed down to the state as shown in Figure 9 , the bottom of the piston abuts against the lower abutting block, and the Y-shaped communication cavity and the communication hole are connected. At this time, the condensed water accumulated at the bottom of the heat exchange pipe sequentially enters the inner cavity of the water inlet pipe through the Y-shaped communication cavity and the communication hole, and finally enters the circulating water, thereby realizing the automatic circulation function of the condensed water accumulated on the inner bottom wall of the heat exchange pipe, reducing the waste of water resources, and at the same time avoiding the influence of the condensed water inside the heat exchange pipe on the subsequent gas transportation. Brief Description of the Drawings

[0022] Figure 1 The figure shows a flowchart of the ammonia synthesis reaction water circulation system;

[0023] Figure 2 The figure shows a schematic three - dimensional structure diagram of a boiler in the prior art of the ammonia synthesis reaction water circulation system;

[0024] Figure 3 The figure shows a front - view structural sectional view of a boiler in the prior art of the ammonia synthesis reaction water circulation system;

[0025] Figure 4 The figure shows a schematic three - dimensional structure diagram of a boiler in the ammonia synthesis reaction water circulation system in the embodiment;

[0026] Figure 5 The figure shows a bottom - view of the internal structure of a boiler in the ammonia synthesis reaction water circulation system in the embodiment;

[0027] Figure 6 The figure shows a top - view of the internal structure of a boiler in the ammonia synthesis reaction water circulation system in the embodiment;

[0028] Figure 7 The figure shows a rate - time graph of the high - temperature hot steam containing SO2 transported from the combustion furnace to the boiler;

[0029] Figure 8 The figure shows a schematic diagram of the closed state of the pressure - appropriate drainage mechanism in the boiler of the ammonia synthesis reaction water circulation system in the embodiment;

[0030] Figure 9 The figure shows a schematic diagram of the open state of the pressure - appropriate drainage mechanism in the boiler of the ammonia synthesis reaction water circulation system in the embodiment.

[0031] In the figure: 10, furnace body; 11, furnace top; 20, heat - exchange pipeline; 21, air outlet hole; 30, main air outlet pipe; 40, water outlet pipe; 50, water inlet pipe; 60, heat - exchange assembly; 61, heat - exchange plate; 62, side plate; 63, bottom plate; 70, pressure - appropriate drainage mechanism; 71, connecting pipe; 711, connecting hole; 72, first magnetic attraction block; 73, piston; 731, Y - shaped communication cavity; 74, second magnetic attraction block; 75, lower abutting block; 76, spring. Detailed Description of the Embodiment

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0033] Embodiment

[0034] When the ammonia synthesis reaction water circulation system of the present invention is working, the acidic gas containing H2S generated by the desulfurization and decarbonization device is transported to the combustion furnace through a pipeline, and over - oxygen combustion is adopted. After high - temperature incineration, the high - temperature steam containing SO2 is sent to the boiler of the present invention. After the boiler recovers heat, the heat is used to heat the circulating water. Finally, the SO2 gas and hot water are sent to the dry - process acid - making device to produce the industrial product H2SO4. Finally, the remaining water flows back and is supplemented by an external make - up water pump to the boiler for reheating, thus forming a water cycle.

[0035] As Figure 4 、 Figure 5 shown, the boiler of the present invention includes:

[0036] The furnace body 10, the top of the furnace body 10 is integrally connected with the furnace top 11. The furnace top 11 is in a conical shape protruding outward, and the top of the conical shape is interconnected with the outlet main pipe 30. The bottom of the furnace body 10 is provided with a water inlet pipe 50;

[0037] The heat - exchange pipeline 20, the heat - exchange pipeline 20 is in the shape of a spring pipeline and is horizontally placed across the inner cavity of the furnace body 10. An air outlet hole 21 is opened at the top of the end of the heat - exchange pipeline 20. The height of the air outlet hole 21 is higher than the drainage liquid level of the furnace body 10, and the diameter of the air outlet hole 21 is smaller than the inner diameter of the heat - exchange pipeline 20;

[0038] The boiler of the present invention replenishes cold circulating water from the water inlet pipe 50, so that a certain height of circulating water is always maintained in the inner cavity of the furnace body 10. The drainage liquid level is less than the height of the air outlet hole 21, but the heat - exchange pipeline 20 is not less than 90% immersed in the circulating water; the high - temperature steam containing SO2 enters the inner cavity of the furnace body 10 through the heat - exchange pipeline 20. The heat - exchange pipeline 20 located in the inner cavity of the furnace body 10 is in the shape of a horizontally placed spring pipeline. Therefore, compared with the straight - tube channels in the prior art, the spring - pipeline - shaped heat - exchange pipeline 20 can have more sufficient contact with the circulating water, increasing the path and time of the high - temperature steam containing SO2 in the pipeline, and thus greatly improving the heat transfer efficiency.

[0039] Moreover, it should be noted that before the SO2 gas is reacted to form SO3 in the dry - process acid - making device, the SO2 gas needs to be filtered to remove the moisture doped in the SO2 gas. In the present invention, because the spring - pipeline - shaped heat - exchange pipeline 20 increases the path and time of the high - temperature steam containing SO2 in the pipeline, the heat steam obtains better heat transfer and heat consumption, and the moisture in the heat steam can be better condensed into water droplets, greatly reducing the water content in the SO2 gas and reducing the burden of subsequent SO2 gas purification;

[0040] Furthermore, heat - exchange components 60 are fixedly connected to the inner walls of the furnace body 10 and the furnace top 11. The heat - exchange components 60 include a bottom plate 63 fixedly connected to the inner wall of the furnace body 10. The top of the bottom plate 63 is fixedly connected with a heat - exchange plate 61, and the heat - exchange plate 61 is in an arc shape;

[0041] In the inner cavity of the boiler of the present invention, a buffer cavity is formed above the drainage liquid level and below the bottom of the main gas outlet pipe 30. The upper half of the arc-shaped heat exchange plate 61 is located in the buffer cavity, and the lower half is located in the circulating water. The buffer cavity contains SO2 gas and the remaining hot steam carried out by the SO2 gas. The arc-shaped heat exchange plate 61 is arranged to further contact the remaining hot steam in the buffer cavity, condense into water droplets on the surface of the heat exchange plate 61 and flow into the circulating water along the heat exchange plate 61, which not only further increases the heat transfer efficiency, but also further reduces the water content in the SO2 gas;

[0042] When the SO2 gas is discharged from the air outlet hole 21, it will carry a part of the condensed water formed after heat exchange. The concave surface of the arc shape of one heat exchange plate 61 is located above the air outlet hole 21, which can prevent the splashing of the part of the condensed water discharged from the air outlet hole 21 and make it flow into the circulating water along the concave surface of the arc shape of the heat exchange plate 61.

[0043] Furthermore, side plates 62 are integrally and fixedly connected to both sides of the heat exchange plate 61, and the side plates 62 extend downward along the curvature of the heat exchange plate 61 from the top of the heat exchange plate 61. By arranging the bottom plate 63, the contact area between the side surface of the heat exchange plate 61 and the buffer cavity can be further increased, the heat transfer efficiency can be further increased, and the water content in the SO2 gas can be further reduced.

[0044] A water outlet pipe 40 is interconnected on the side wall of the furnace body 10, and the water outlet pipe 40 is flush with the drainage liquid level in the inner cavity of the furnace body 10. The other end of the water outlet pipe 40 is connected to the dry acid-making device to provide hot water to the dry acid-making device. Compared with cold water, hot water can react better with SO3 gas to generate H2SO4.

[0045] As Figure 7 shown, it is a rate-time diagram of the combustion furnace delivering high-temperature hot steam containing SO2 to the boiler. In one round of the delivery stage, it includes an initial stage (0 - t1), starting combustion, and the combustion is not complete; a peak stage (t1 - t2), a full combustion stage; and a decay stage (t2 - t3), the combustibles decrease and the combustion declines. Since the inner diameter of the pipeline of the heat exchange pipeline 20 and the aperture of the air outlet hole 21 are constant, as the delivery rate increases, the air pressure in the inner cavity of the heat exchange pipeline 20 increases accordingly, and vice versa. In the initial stage (0 - t1) and the decay stage (t2 - t3) of the present invention, the air pressure in the inner cavity of the heat exchange pipeline 20 is less than P; in the peak stage (t1 - t2), the air pressure in the inner cavity of the heat exchange pipeline 20 is greater than P.

[0046] As Figure 8 、 Figure 9 shown, a pressure-adaptive drainage mechanism 70 is arranged at the bottom of the heat exchange pipeline 20, and the pressure-adaptive drainage mechanism 70 extends into the inner cavity of the water inlet pipe 50.

[0047] The pressure - adaptable drainage mechanism 70 includes a connecting pipe 71 that is interconnected with the bottom of the heat - exchange pipe 20. The bottom of the connecting pipe 71 is fixedly inserted into the water inlet pipe 50. A communication hole 711 is formed in the side wall of the connecting pipe 71, and a pressure - dependent drainage component is arranged inside the connecting pipe 71. The connecting pipe 71 has a round - outside and square - inside shape, and the outer diameter of the connecting pipe 71 is smaller than the inner diameter of the water inlet pipe 50. The pressure - dependent drainage component includes a piston 73 in the inner cavity of the connecting pipe 71. A Y - shaped communication cavity 731 is formed inside the piston 73. A first magnetic attraction block 72 is fixedly connected to the inner wall of the connecting pipe 71. A second magnetic attraction block 74 is fixedly connected in an embedded manner to the top of the piston 73, and the second magnetic attraction block 74 faces the first magnetic attraction block 72. A spring 76 is fixedly connected between the piston 73 and the inner wall of the bottom of the connecting pipe 71. A lower abutting block 75 is fixedly connected to the inner wall of the connecting pipe 71, and the lower abutting block 75 is located below the communication hole 711.

[0048] In the present invention, after the high - temperature hot steam containing SO2 entering the heat - exchange pipe 20 exchanges heat with the circulating water, the water in the hot steam will condense into water droplets and flow down along the inner wall of the heat - exchange pipe 20 to the bottom; in one round of the conveying stage, in the initial stage (0 - t1) and the attenuation stage (t2 - t3), the air pressure in the inner cavity of the heat - exchange pipe 20 is less than P. At this time, as Figure 8 shown, the second magnetic attraction block 74 and the first magnetic attraction block 72 are adsorbed to each other, and the spring 76 is in a compressed state, providing an upward elastic force for the piston 73. At this time, the Y - shaped communication cavity 731 and the communication hole 711 are not connected; when in the peak stage (t1 - t2), the air pressure in the inner cavity of the heat - exchange pipe 20 is greater than P, and the air pressure is greater than the sum of the magnetic attraction forces of the first magnetic attraction block 72 and the second magnetic attraction block 74 plus the elastic force of the spring 76. At this time, the piston 73 is pushed down to the state as shown in Figure 9 At this time, the bottom of the piston 73 abuts against the lower abutting block 75, and the Y - shaped communication cavity 731 and the communication hole 711 are connected. At this time, the condensed water accumulated at the bottom of the heat - exchange pipe 20 sequentially passes through the Y - shaped communication cavity 731 and the communication hole 711 and flows into the inner cavity of the water inlet pipe 50, and finally flows into the circulating water, thus realizing the automatic circulation function of the condensed water accumulated on the inner bottom wall of the heat - exchange pipe 20, and at the same time avoiding the influence of the condensed water inside the heat - exchange pipe 20 on the subsequent gas transportation.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it.

Claims

1. Ammonia synthesis reaction water circulation system, including a combustion furnace, a boiler, an acid-making device and a makeup water pump, characterized in that, The boiler includes: A furnace body (10), the top of the furnace body (10) is integrally connected with a furnace top (11), the furnace top (11) is in a conical shape protruding outward, and the top of the conical shape is interconnected with an outlet main pipe (30), and a water inlet pipe (50) is arranged at the bottom of the furnace body (10); A heat exchange pipe (20), the heat exchange pipe (20) is in the shape of a spring pipe and is horizontally disposed in the inner cavity of the furnace body (10), an air outlet hole (21) is opened at the top of the end of the heat exchange pipe (20), the height of the air outlet hole (21) is higher than the drainage liquid level of the furnace body (10), and the aperture of the air outlet hole (21) is smaller than the inner diameter of the heat exchange pipe (20); SO2 and hot steam formed after the combustion furnace burns acidic gas enter the inner cavity of the furnace body (10) through the heat exchange pipe (20). The spring pipe-shaped heat exchange pipe (20) in the inner cavity of the furnace body (10) increases the heat exchange between the hot steam and the circulating water in the furnace body (10). After heat exchange, the gas overflows upward from the air outlet hole (21) and is finally transported to the acid-making device through the outlet main pipe (30); Heat exchange components (60) are fixedly connected to the inner walls of the furnace body (10) and the furnace top (11). The heat exchange components (60) include a bottom plate (63) fixedly connected to the inner wall of the furnace body (10). A heat exchange plate (61) is fixedly connected to the top of the bottom plate (63). The heat exchange plate (61) is in an arc shape, and the concave surface of the arc shape of one of the heat exchange plates (61) is located above the air outlet hole (21); A pressure-adaptive drainage mechanism (70) is arranged at the bottom of the heat exchange pipe (20), and the pressure-adaptive drainage mechanism (70) extends into the inner cavity of the water inlet pipe (50); The pressure-adaptive drainage mechanism (70) includes a communicating pipe (71) interconnected with the bottom of the heat exchange pipe (20), and the bottom of the communicating pipe (71) is fixedly inserted on the water inlet pipe (50). A communicating hole (711) is opened on the side wall of the communicating pipe (71), and a pressure-dependent drainage component is arranged inside the communicating pipe (71); The communicating pipe (71) is in a shape with a round outer and a square inner, and the outer diameter of the communicating pipe (71) is smaller than the inner diameter of the water inlet pipe (50); The pressure-dependent drainage component includes a piston (73) in the inner cavity of the communicating pipe (71). A Y-shaped communicating cavity (731) is opened inside the piston (73). A first magnetic attraction block (72) is fixedly connected to the inner wall of the communicating pipe (71). A second magnetic attraction block (74) is fixedly connected in an embedded manner at the top of the piston (73), and the second magnetic attraction block (74) faces the first magnetic attraction block (72). A spring (76) is fixedly connected between the piston (73) and the bottom inner wall of the communicating pipe (71); A lower abutting block (75) is fixedly connected to the inner wall of the communicating pipe (71), and the lower abutting block (75) is located below the communicating hole (711).

2. The ammonia synthesis reaction water circulation system according to claim 1, characterized in that Side plates (62) are integrally and fixedly connected to both sides of the heat exchange plate (61), and the side plates (62) extend downward along the radian of the heat exchange plate (61) from the top of the heat exchange plate (61).

3. The ammonia synthesis reaction water circulation system according to claim 1, characterized in that, A water outlet pipe (40) is interconnected with the side wall of the furnace body (10), and the water outlet pipe (40) is flush with the drainage liquid level in the inner cavity of the furnace body (10).

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