Nitric acid three-in-one unit continuous production system

Abstract

The utility model discloses a nitric acid three-in-one unit continuous production system which comprises a first unit (2) and a second unit (3) which are arranged in parallel, heat pipelines of the first unit (2) and the second unit (3) are converged and then connected with a heat control pump (5), and raw material channels are converged and then connected with a raw material control pump (6). According to the utility model, two parallel three-in-one units are arranged, so that the problem that the existing process is not suitable for continuous production of the units is solved, and the problems that the catalyst cannot be recycled and efficiently utilized and the energy of the three-in-one units is not fully utilized are solved by collecting poisoned and damaged catalyst nets and utilizing the energy of the three-in-one units for catalyst regeneration; the device has practical significance on green production of nitric acid, energy conservation and consumption reduction.

Description

Technical Field

[0001] The utility model relates to the technical field of nitric acid production, in particular to a continuous production system of a nitric acid three-in-one unit. Background Art

[0002] Nitric acid is one of the important basic chemical industrial products. Among various acids, its output ranks second only to sulfuric acid. Most nitric acid is used in the manufacture of fertilizers, including nitrogen fertilizers and various compound fertilizers. Nitric acid is also a raw material for manufacturing trinitrotoluene (TNT), picric acid, nitrocellulose, nitroglycerin, and mercury fulminate. Nitric acid plays an important role in medicine, non-ferrous metallurgy, and atomic energy. The nitric acid industry is directly related to the development of China's agriculture and chemical industry.

[0003] The industrial production of nitric acid all adopts the ammonia oxidation process with ammonia and air as raw materials and a platinum-rhodium alloy as a catalyst. Its core equipment is the "three-in-one unit" (prime mover, air compressor, and turbine expander). However, this method has a relatively high loss of the catalyst platinum. When the catalyst fails, the production efficiency will be reduced, and the catalyst mesh must be replaced, which will cause the machine to stop and the equipment cannot be continuously produced. At the same time, a large amount of heat generated during the operation of the three-in-one unit needs to be discharged in time, and direct discharge also causes energy waste. The patent "CN221527328U A heat exchange device for energy saving and production increase in dilute nitric acid production" solves the technical problems of high inlet gas temperature and low tail gas temperature in the current dilute nitric acid production. However, its improvement of the heat exchange system does not improve the continuous production of the three-in-one unit. Therefore, ensuring the continuous production of the unit, the efficient recycling of the catalyst, and the full utilization of the energy of the three-in-one unit are the key development directions of nitric acid-related enterprises. Summary of the Utility Model

[0004] The utility model provides a continuous production system of a nitric acid three-in-one unit, which solves the problems that the existing process is not suitable for the continuous production of the unit, the catalyst cannot be recycled efficiently, and the energy of the three-in-one unit is not fully utilized.

[0005] To solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A nitric acid three-in-one unit continuous production system comprises a first unit and a second unit arranged in parallel, wherein the heat pipes of the first unit and the second unit are connected to a heat control pump after merging, and the raw material passage is connected to a raw material control pump after merging. In this preferred solution, the first unit and the second unit are both three-in-one units. By setting the first unit and the second unit arranged in parallel, the key process of nitric acid production is optimized, and the two units have the same functions, can replace each other, and back up each other to achieve continuous production of the unit. Since a large amount of heat is generated during the operation of the three-in-one unit, it is necessary to use external means to process this part of the heat. If it is directly emptied, it not only wastes heat energy, but also increases the energy consumption for cooling. Therefore, this part of energy is collected and subsequently distributed and used by a heat control pump to achieve full utilization of the energy of the three-in-one unit. During the operation of the three-in-one unit, catalyst poisoning will occur. After a certain production cycle, the catalyst net needs to be updated. After the unit is shut down, the poisoned and ineffective catalyst net is removed, and the residual catalyst powder dropped in the collection equipment is flushed, and the subsequent catalyst regeneration step is entered through the raw material control pump to achieve efficient utilization of the catalyst cycle.

[0007] Furthermore, the unit raw material pipeline is connected to the first unit and the second unit respectively after passing through the unit inlet control pump; the outlet pipelines of the first unit and the second unit meet at the unit outlet control pump. In this preferred solution, the inlet and outlet materials of the first unit and the second unit in parallel are controlled by adjusting the unit inlet control pump and the unit outlet control pump, and adapted to the working status of the two three-in-one units: the two units can complete the production tasks independently or separately, so by adjusting the working status of the unit or whether it is working or not, the catalyst poisoning of the two units is avoided at the same time, and at least one unit is guaranteed to work normally, and the other unit can be shut down for maintenance or catalyst regeneration.

[0008] Furthermore, the heat control pump is connected to the first calcining furnace and the second calcining furnace respectively. In this preferred solution, the heat generated by the three-in-one unit during production is adjusted by the heat control pump, and the heat source of the first calcining furnace and the second calcining furnace is guaranteed according to the needs of the catalyst regeneration process.

[0009] Furthermore, the raw material control pump is connected to the first reaction tank. In this preferred embodiment, the raw material control pump inputs the catalyst powder suspension from the unit into the first reaction tank for preliminary reaction.

[0010] Furthermore, the first reaction tank is connected to the precipitation tank and the second calcining furnace respectively. In this preferred embodiment, in the precipitation tank, aqua regia is leached and rhodium is separated, the rhodium is collected and input into the second calcining furnace, and the remaining solution enters the precipitation tank.

[0011] Furthermore, the precipitation tank is connected to the first calcining furnace, the second reaction tank and the second calcining furnace in sequence. In this preferred embodiment, ammonium chloride is added to the precipitation tank to obtain ammonium salt precipitation of platinum, the precipitation is collected and transported to the first calcining furnace, calcined to obtain sponge platinum, the sponge platinum is transported to the second reaction tank, acid-dissolved to drive out nitrate to obtain chloroplatinic acid, chloroplatinic acid is sequentially precipitated with potassium chloride, reduced with potassium oxalate to obtain potassium chloroplatinite, then hydrolyzed with potassium hydroxide, impurity ions such as potassium chloride are removed, and neutralized with nitric acid to obtain high-purity platinum nitrate, which is then transported to the second calcining furnace.

[0012] Furthermore, a wire drawing and weaving machine is provided at the outlet of the second calcining furnace. In this preferred embodiment, the second calcining furnace mixes the platinum from the second reaction pool and the rhodium from the first reaction pool in proportion, calcines them, and conveys the alloy to the wire drawing and weaving machine to obtain a catalyst mesh of appropriate size for the three-in-one unit.

[0013] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0014] (1) The first unit (2) and the second unit (3) of the utility model are both three-in-one units. By setting the first unit (2) and the second unit (3) arranged in parallel, the key process of nitric acid production is optimized. The two units have the same functions and can replace each other and serve as backup for each other, so as to realize continuous production of the units. Since a large amount of heat is generated during the operation of the three-in-one unit, it is necessary to use external means to process this part of the heat. If it is directly emptied, it not only wastes heat energy, but also increases the energy consumption for cooling. Therefore, this part of energy is collected and subsequently distributed and used by the heat control pump (5) to realize full utilization of the energy of the three-in-one unit. During the operation of the three-in-one unit, catalyst poisoning will occur. After a certain production cycle, the catalyst net needs to be updated. After the unit is shut down, the poisoned and ineffective catalyst net is removed, and the residual catalyst powder dropped in the collection equipment is flushed. The subsequent catalyst regeneration step is entered through the raw material control pump (6) to realize efficient utilization of the catalyst cycle.

[0015] (2) The utility model controls the inlet and outlet materials of the first unit (2) and the second unit (3) connected in parallel by adjusting the unit inlet control pump (1) and the unit outlet control pump (4), and adapts to the working conditions of the two three-in-one units: the two units can complete production tasks independently or separately. Therefore, by adjusting the working conditions of the units or whether they are working or not, catalyst poisoning of the two units can be avoided at the same time, ensuring that at least one unit works normally, and the other unit can be shut down for maintenance or catalyst regeneration.

[0016] (3) The heat generated during the production of the three-in-one unit is regulated by the heat control pump (5) of the present utility model to ensure the heat sources of the first calcination furnace (8) and the second calcination furnace (11) according to the requirements of the catalyst regeneration process. The raw material control pump (6) inputs the catalyst powder suspension from the unit into the first reaction tank (7) for preliminary reaction. In the sedimentation tank (8), rhodium is leached out and separated by aqua regia, and the collected rhodium is input into the second calcination furnace (11), while the remaining solution enters the sedimentation tank (8). Ammonium chloride is added to the sedimentation tank (8) to obtain the ammonium salt precipitate of platinum. The collected precipitate is transported to the first calcination furnace (9), where it is calcined to obtain sponge platinum. The sponge platinum is transported to the second reaction tank (10), where it is acid-dissolved to remove nitrates to obtain chloroplatinic acid. The chloroplatinic acid is successively precipitated with potassium chloride, reduced with potassium oxalate to obtain potassium chloroplatinate, and then hydrolyzed with potassium hydroxide, the impurity ions such as chlorine and potassium are removed, and neutralized with nitric acid to obtain high-purity platinum nitrate. The high-purity platinum nitrate is transported to the second calcination furnace (11). The second calcination furnace (11) mixes the platinum from the second reaction tank (10) and the rhodium from the first reaction tank (7) in proportion, calcines them, and transports the alloy to the wire drawing and weaving machine (12) to obtain a catalyst mesh of appropriate size for the three-in-one unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the present utility model.

[0018] In the figure: 1, inlet control pump of the unit; 2, first unit; 3, second unit; 4, outlet control pump of the unit; 5, heat control pump; 6, raw material control pump; 7, first reaction tank; 8, sedimentation tank; 9, first calcination furnace; 10, second reaction tank; 11, second calcination furnace; 12, wire drawing and weaving machine. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In order to enable those skilled in the art to more clearly understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below in combination with specific embodiments. It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanations of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0020] Refer to the attached Figure 1As shown, the embodiment of the utility model provides a nitric acid three-in-one unit continuous production system, including a first unit 2 and a second unit 3 arranged in parallel, wherein the heat pipelines of the first unit 2 and the second unit 3 are connected to a heat control pump 5 after merging, and the raw material passages are connected to a raw material control pump 6 after merging. After the unit raw material pipeline passes through the unit inlet control pump 1, it is connected to the first unit 2 and the second unit 3 respectively; the outlet pipelines of the first unit 2 and the second unit 3 are merged at the unit outlet control pump 4. The heat control pump 5 is connected to the first calcining furnace 8 and the second calcining furnace 11 respectively. The raw material control pump 6 is connected to the first reaction tank 7. The first reaction tank 7 is connected to the sedimentation tank 8 and the second calcining furnace 11 respectively. The sedimentation tank 8 is connected to the first calcining furnace 9, the second reaction tank 10 and the second calcining furnace 11 in sequence. A wire drawing braiding machine 12 is arranged at the outlet of the second calcining furnace 11.

[0021] When in use, the first unit 2 and the second unit 3 of the utility model are both three-in-one units. By setting the first unit 2 and the second unit 3 arranged in parallel, the key process of nitric acid production is optimized. The two units have the same functions and can replace each other and back up each other to achieve continuous production of the unit. Since a large amount of heat is generated during the operation of the three-in-one unit, it is necessary to use external means to process this part of the heat. If it is directly emptied, it not only wastes heat energy, but also increases the energy consumption for cooling. Therefore, this part of energy is collected and used for subsequent distribution through the heat control pump 5 to achieve full utilization of the energy of the three-in-one unit. During the operation of the three-in-one unit, catalyst poisoning will occur. After a certain production cycle, the catalyst net needs to be updated. After the unit is shut down, the poisoned catalyst net is removed, and the residual catalyst powder dropped in the flushing collection equipment is rinsed. The subsequent catalyst regeneration step is entered through the raw material control pump 6 to achieve efficient utilization of the catalyst cycle.

[0022] By adjusting the unit inlet control pump 1 and the unit outlet control pump 4, the inlet and outlet materials of the parallel first unit 2 and the second unit 3 are controlled to adapt to the working conditions of the two three-in-one units: the two units can complete production tasks independently or separately. Therefore, by adjusting the working conditions of the units or whether they are working or not, catalyst poisoning of the two units at the same time can be avoided, and at least one unit can be guaranteed to work normally, and the other unit can be shut down for maintenance or catalyst regeneration.

[0023] The heat generated during the production of the three-in-one unit is regulated by the heat control pump 5 to ensure the heat sources of the first calcination furnace 8 and the second calcination furnace 11 according to the requirements of the catalyst regeneration process. The raw material control pump 6 inputs the catalyst powder suspension from the unit into the first reaction tank 7 for preliminary reaction. In the sedimentation tank 8, rhodium is leached and separated by aqua regia, and the collected rhodium is input into the second calcination furnace 11, and the remaining solution enters the sedimentation tank 8. Ammonium chloride is added to the sedimentation tank 8 to obtain the ammonium salt precipitate of platinum, and the collected precipitate is transported to the first calcination furnace 9 for calcination to obtain sponge platinum. The sponge platinum is transported to the second reaction tank 10, and after acid dissolution and removal of nitrates, chloroplatinic acid is obtained. Chloroplatinic acid is successively precipitated with potassium chloride, reduced with potassium oxalate to obtain potassium chloroplatinate, and then hydrolyzed with potassium hydroxide, the removal of miscellaneous ions such as potassium chloride, and neutralized with nitric acid to obtain high-purity platinum nitrate. The high-purity platinum nitrate is transported to the second calcination furnace 11. The second calcination furnace 11 mixes the platinum from the second reaction tank 10 and the rhodium from the first reaction tank 7 in proportion, calcines, and transports the alloy to the wire drawing and weaving machine 12 to obtain a catalyst mesh of appropriate size for the three-in-one unit.

[0024] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A continuous production system for a nitric acid triple unit, characterized in that, It includes a first unit (2) and a second unit (3) arranged in parallel. After the heat pipelines of the first unit (2) and the second unit (3) converge, they are connected to a heat control pump (5). After the raw material pipelines converge, they are connected to a raw material control pump (6).

2. The continuous production system of the nitric acid triple unit according to claim 1, characterized in that, After passing through the unit inlet control pump (1), the raw material pipelines of the units are respectively connected to the first unit (2) and the second unit (3). The outlet pipelines of the first unit (2) and the second unit (3) converge at the unit outlet control pump (4).

3. The continuous production system of the nitric acid triple unit according to claim 1, characterized in that, The heat control pump (5) is respectively connected to the first calciner (9) and the second calciner (11).

4. The continuous production system of the nitric acid triple unit according to claim 1, wherein The raw material control pump (6) is connected to the first reaction tank (7).

5. The continuous production system of the nitric acid triple unit according to claim 4, wherein, The first reaction tank (7) is respectively connected to the sedimentation tank (8) and the second calciner (11).

6. The continuous production system of the nitric acid triple unit according to claim 5, characterized in that, The sedimentation tank (8) is successively connected to the first calciner (9), the second reaction tank (10) and the second calciner (11).

7. The continuous production system of the nitric acid triple unit according to claim 6, characterized in that, A wire drawing and braiding machine (12) is arranged at the outlet of the second calciner (11).

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