Low-energy-consumption industrial nitric acid production process

Abstract

The invention relates to the technical field of industrial nitric acid production, in particular to a low-energy-consumption industrial nitric acid production process which comprises an absorption tower, a second sprayer is matched with the second sprayer, more water reacts with the absorption tower when the nitrogen dioxide content at the bottom of the absorption tower is large, the reaction is promoted to tend to be carried out in the direction of products, and the production efficiency is improved. The contact area of water drops and nitrogen oxide gas is increased by utilizing the rotating sprayer I and the rotating sprayer II, the reaction efficiency is further improved, the situation that sprayed water mist is overlapped when vertically falling is reduced by utilizing the sprayer I and the sprayer II with different rotating speeds, so that the contact area of the water drops and the nitrogen oxide gas is further increased, and the reaction efficiency is further improved. Compared with a traditional absorption tower, through cooperation of the first opening and closing frame and the second opening and closing frame, the time that NOx gas stays in the absorption tower is prolonged while the processing space is reduced, meanwhile, the pressure intensity in the absorption tower is increased, and therefore the reaction is promoted to be fully carried out in the forward direction.

Description

Technical Field

[0001] The invention relates to the technical field of industrial nitric acid production, in particular to a low-energy consumption industrial nitric acid production process. Background Art

[0002] Nitric acid is a colorless liquid with strong oxidizing and corrosive properties. It is widely used in explosives, fertilizers, metal processing and other fields. Its processing flow is mainly as follows: ammonia is oxidized on a platinum catalyst to generate NO, and NO is further oxidized to NO2. However, the entire oxidation reaction cannot completely oxidize NO to NO2. Therefore, after the oxidation reaction, there are NO and NO2 in the oxidation tower, which are represented by NOx here. The NO2 in NOx is then absorbed in the absorption tower to generate dilute nitric acid. The produced dilute nitric acid is passed into the cooling system and the concentration tower for concentration and cooling to generate concentrated nitric acid, which is then collected and stored, cooled and distilled to finally produce concentrated nitric acid. In the whole process, the reaction of the absorption tower is particularly important, so it is necessary to increase the content of reaction products in the absorption tower.

[0003] The reaction efficiency of the traditional absorption tower increases as the reaction proceeds, and the products of dilute nitric acid and NO increase, thereby inhibiting the forward progress of the reaction. The heat generated during the reaction gradually increases, further inhibiting the forward progress of the reaction, resulting in the reaction efficiency gradually decreasing as the reaction proceeds, thereby reducing the production efficiency in the absorption tower. Summary of the invention

[0004] In view of the above problems, the present application provides a low-energy consumption industrial nitric acid production process to solve the technical problem in the related art that the production efficiency in the absorption tower decreases as the reaction proceeds. In order to achieve the above purpose, the present application provides the following technical solutions.

[0005] A low-energy consumption industrial nitric acid production process according to an embodiment of the present application comprises the following steps: S1. Preparation of ammonia: firstly, liquid ammonia is fed into an ammonia evaporator, and after evaporating the gaseous ammonia, it is passed into an ammonia superheater for filtration to remove impurities.

[0006] S2. Oxidation of ammonia: After filtering, the gaseous ammonia is mixed with air and heated in an oxidation tower for catalytic oxidation to produce NOx.

[0007] S3. Absorption of nitrogen oxides: After the excess heat of the NOx gas is recovered, cooled and pressurized, the NOx gas is sent to the absorption tower to be absorbed by water to form dilute nitric acid. The small amount of NOx gas that has not reacted completely and the product NO gas are again introduced into the oxidation tower for catalytic oxidation.

[0008] S4. Generation of concentrated nitric acid: The produced dilute nitric acid is passed into a concentration tower for concentration and cooling to generate concentrated nitric acid, which is then collected and stored.

[0009] Wherein step S3 is completed by using a low-energy consumption industrial nitric acid production equipment, the production equipment includes an absorption tower, a reflux pipe is fixedly installed on the left end of the upper side of the absorption tower, a gas pump is fixedly connected to the end of the reflux pipe, the gas pump is fixedly connected to the oxidation tower, a gas drive frame is fixedly installed on the left end of the absorption tower, a control frame is commonly arranged between the gas drive frame and the absorption tower, a transport pump is fixedly connected between the gas drive frame and the oxidation tower, a water inlet is fixedly installed in the middle of the upper side of the absorption tower, a delivery pump is fixedly installed on the upper end of the water inlet, an acid discharge pipe is fixedly installed on the right end of the lower side of the absorption tower, an exhaust pipe is fixedly installed on the upper right end of the absorption tower, a high-temperature resistant valve is fixedly installed in the exhaust pipe, and the structures of the absorption tower and the oxidation tower are both prior art; a No. 1 spray rack is arranged inside the absorption tower and at the lower end of the water inlet, a sliding valve is fixedly installed in the middle of the lower end of the water inlet A shunt pipe that runs through the No. 1 spray rack is fixedly installed at the lower end of the shunt pipe. Fixed rods are evenly fixedly installed on the inner wall of the absorption tower. The ends of the fixed rods are commonly fixedly connected with a condensation rack. An opening and closing rack 1 is arranged on the inner ring wall of the absorption tower and located on the upper side of the No. 2 spray rack. An opening and closing rack 2 is arranged on the inner ring wall of the absorption tower and located on the upper side of the No. 1 spray rack. A linkage rack 1 is arranged on the opening and closing rack 1, and a linkage rack 2 is arranged on the opening and closing rack 2. The gas transmission drive frame includes a gas transmission pipe, a gas transmission pipe is fixedly installed on the left end of the absorption tower, a rotating ring is rotatably connected to the inner end of the gas transmission pipe, fan blades are evenly fixedly installed on the inner ring wall of the rotating ring, a ring gear is fixedly installed on the outer ring wall of the rotating ring, a motor 1 is fixedly installed on the outer ring wall of the gas transmission drive frame through a motor seat, a spur gear meshing with the ring gear is fixedly installed on the output shaft of the motor 1 through a coupling, and a round head pipe is commonly fixedly installed on the ends of the fan blades.

[0010] According to an embodiment of the present invention, the condensing rack includes a main spiral tube, the ends of the fixing rods are commonly fixedly connected with the main spiral tube, the outer ends of the main spiral tubes are evenly provided with side spiral tubes, the main spiral tubes and the side spiral tubes are fixedly connected by supporting rods, the upper ends of the main spiral tubes and the upper ends of the side spiral tubes are commonly fixedly installed with a drain pipe, the lower ends of the main spiral tubes and the lower ends of the side spiral tubes are commonly fixedly installed with a water inlet pipe, and the cross-sectional radius of the main spiral tube is larger than the cross-sectional radius of the side spiral tube and smaller than the cross-sectional diameter of the side spiral tube.

[0011] According to an embodiment of the present invention, the control frame includes a gear ring, a gear ring is fixedly installed on the right side of the outer ring wall of the rotating ring, a cylindrical gear meshing with the gear ring is rotatably connected to the inner end of the upper side of the gas pipe, a bevel gear 1 is fixedly installed on the right end of the cylindrical gear and located at the inner end of the upper side of the gas pipe, a bevel gear 2 meshing with the bevel gear 1 is rotatably connected to the upper end of the gas pipe, the bevel gear 2 is rotatably connected to the absorption tower, and a driving gear 1 and a driving gear 2 are fixedly installed on the upper end of the bevel gear 2 from top to bottom, respectively, and the diameter of the driving gear 2 is larger than the diameter of the driving gear 1; the driving gear 1 and the driving gear 2 with different diameters are used to ensure that the rotation cycles of the No. 1 spray rack and the No. 2 spray rack are different.

[0012] According to an embodiment of the present invention, the No. 1 spray rack includes a sprayer 1, which is fixedly installed inside the absorption tower and at the lower end of the water inlet, and a driven gear ring 1 is fixedly installed on the outer ring wall of the sprayer 1, and the driven gear ring 1 is meshed with the driving gear 1. The No. 2 spray rack includes a sprayer 2, which is fixedly installed at the lower end of the diversion pipe, and a driven gear ring 2 is fixedly installed on the outer end of the sprayer 2, and the driven gear ring 2 is meshed with the driving gear 2. The structures of the sprayer 1 and the sprayer 2 are both prior arts.

[0013] According to an embodiment of the present invention, the water inlet component includes a distilled water inlet pipe, which is fixedly installed on the middle part of the upper side of the absorption tower, and an annular groove is opened at the lower end of the distilled water inlet pipe, a connecting ring is rotatably connected in the annular groove, a connecting pipe is fixedly installed at the lower end of the connecting ring, the lower end of the connecting pipe slides through the opening and closing frame 2 and is fixedly connected to the No. 1 spray rack, a connecting rod is evenly fixedly installed on the inner ring wall of the lower side of the connecting pipe, and a fixed ring plate is commonly fixedly installed on the end of the connecting rod, and a rotating ring plate is rotatably connected to the inner ring wall of the fixed ring plate, the lower end of the rotating ring plate is fixedly connected to the diverter pipe, and the lower end of the diverter pipe slides through the No. 1 spray rack and the opening and closing frame 1 and is finally fixedly connected to the No. 2 spray rack; the rotation of the No. 1 spray rack is prevented from interfering with the rotation of the No. 1 spray rack by the rotational connection between the connecting pipe and the distilled water inlet pipe, and the rotation of the No. 2 spray rack is prevented from interfering with the cooperation of the fixed ring plate and the rotating ring plate.

[0014] According to an embodiment of the present invention, the opening and closing frame includes a circular plate, which is fixedly installed on the inner ring wall of the absorption tower and located on the upper side of the No. 2 spray rack, and fan-shaped holes are evenly opened on the circular plate. A rotating column is rotatably connected to the upper end of the circular plate, and the rotating column is rotatably connected to the diversion pipe. A fan-shaped baffle is evenly fixedly installed on the outer end of the rotating column. In the initial state, the fan-shaped baffle and the fan-shaped hole are staggered up and down; the opening and closing of the fan-shaped hole is controlled by the rotation of the rotating column and the fan-shaped baffle.

[0015] According to an embodiment of the present invention, the second opening and closing frame includes a second circular plate, which is fixedly installed on the inner ring wall of the absorption tower and located on the upper side of the No. 1 spray rack. The second circular plate is evenly provided with two fan-shaped holes. The upper end of the second circular plate is rotatably connected to a second rotating column, and the outer end of the second rotating column is evenly fixedly installed with a second fan-shaped baffle. In the initial state, the second fan-shaped baffle is aligned with the second fan-shaped hole up and down.

[0016] According to an embodiment of the present invention, the linkage frame 1 includes a matching gear ring 1, all the fan-shaped baffles 1 are fixedly installed with a matching gear ring 1 near one end of the inner ring wall of the absorption tower, the upper end of the circular plate 1 is rotatably connected with a matching gear that matches the matching gear ring 1, the upper end of the active gear 2 and located on the left side of the matching gear ring 1 is rotatably connected with a matching circular plate 1, a gear block 1 is fixedly installed on the right end of the matching circular plate 1, the lower end of the matching gear slides through the circular plate 1 and is fixedly installed with a linkage gear, the linkage gear matches the gear block 1, and the structure of the linkage frame 2 is the same as that of the linkage frame 1.

[0017] According to an embodiment of the present invention, a connecting pipe is fixedly connected between the drainage terminal pipe openings of the main spiral pipe and the side spiral pipe, and the terminal pipe openings of the main spiral pipe and the side spiral pipe are rotatably connected with an arc-shaped baffle plate through a pin shaft, and a torsion spring is sleeved on the pin shaft, one end of the torsion spring is fixedly connected to the corresponding arc-shaped baffle plate, and the other end of the torsion spring is fixedly connected to the corresponding main spiral pipe or side spiral pipe.

[0018] According to an embodiment of the present invention, a pH meter is fixedly installed at the left pipe opening of the acid discharge pipe, and an acid-resistant valve is fixedly installed inside the acid discharge pipe.

[0019] It can be seen from the above technical solutions that the present invention has the following advantages:

[0020] 1. In the present invention, NOx gas is transported by a gas transmission drive frame, and the rotation of the No. 1 spray rack and the No. 2 spray rack and the opening and closing of the opening and closing frame 1 and the opening and closing frame 2 are controlled at the same time. The No. 1 spray rack and the No. 2 spray rack cooperate with each other, so that when the amount of nitrogen dioxide at the bottom of the absorption tower is large, there is more water to react with it, thereby promoting the reaction to proceed in the direction of the product. The rotating No. 1 spray rack and the rotating No. 2 spray rack are used to increase the contact area between water droplets and nitrogen oxide gas, thereby further improving the reaction efficiency. At the same time, the sprayer 1 and the sprayer 2 with different rotation speeds are used to reduce the overlap of the water mist sprayed by the sprayer 1 and the sprayer 2 when they fall vertically, thereby further increasing the contact area between water droplets and nitrogen oxide gas, causing the reaction to proceed in the direction of the product, thereby improving the reaction efficiency. Compared with the traditional absorption tower, the opening and closing frame 1 cooperates with the opening and closing frame 2, while reducing the processing space and prolonging the time that NOx gas stays in the absorption tower, and at the same time increasing the pressure in the absorption tower, thereby promoting the reaction to proceed fully in the forward direction.

[0021] 2. In the present invention, the flow rate of condensed water is reduced by the main spiral tube and the side spiral tube, while its contact area with the outside is increased, the condensation effect is improved, and the heat generated by the reaction is reduced, so that the reaction tends to proceed in the direction of the product, and the reaction efficiency is improved, so as to achieve the purpose of reducing energy consumption costs while improving reaction efficiency.

[0022] 3. In the present invention, the contact area between the water droplets and the nitrogen oxide gas is increased by rotating the sprayer 1 and the sprayer 2 while spraying, thereby further improving the reaction efficiency. At the same time, the sprayer 1 and the sprayer 2 with different rotation speeds are used to avoid the overlap of the water mist they spray, thereby further increasing the contact area between the water droplets and the nitrogen oxide gas, making the reaction tend to proceed in the direction of the product, and improving the reaction efficiency.

[0023] In addition to the technical problems solved by the embodiments of the present application described above, the technical features that constitute the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions, other technical problems that can be solved by a low-energy industrial nitric acid production process provided by the embodiments of the present application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0025] Figure 1 A workflow diagram of the present invention is shown.

[0026] Figure 2 A schematic diagram of a main-view stereoscopic structure provided according to an embodiment of the present invention is shown.

[0027] Figure 3 A schematic diagram of the main stereoscopic structure of the condensing frame, the opening and closing frame 1, the opening and closing frame 2 and the linkage frame 1 is shown.

[0028] Figure 4 A schematic diagram of the main stereoscopic structure of the opening and closing frame 1, the opening and closing frame 2 and the linkage frame 1 is shown.

[0029] Figure 5 A schematic diagram of a main cross-sectional plane structure provided according to an embodiment of the present invention is shown.

[0030] Figure 6 Shows Figure 5 A local enlarged view of location N.

[0031] Figure 7 Shows Figure 5 A local enlarged view of point M.

[0032] Figure 8 Shows Figure 5 A local enlarged view of point E.

[0033] Fig. 9 Shows Figure 5 A partial enlarged view of point F.

[0034] Fig.10 Shows Figure 5 A local enlarged view of point G.

[0035] Fig.11 A schematic diagram of the right side cross-sectional plan structure of the condensation rack is shown.

[0036] The above drawings include the following reference numerals:

[0037] 1. Absorption tower; 11. No. 1 spray rack; 111. Sprayer 1; 112. Driven gear ring 1; 12. Diverter pipe; 13. No. 2 spray rack; 131. Sprayer 2; 132. Driven gear ring 2; 14. Fixed rod; 15. Condensation rack; 151. Main spiral tube; 1511. Connecting tube; 1512. Arc baffle; 1513. Torsion spring; 152. Support rod; 153. Side spiral Rotary pipe; 154, drainage pipe; 155, water inlet pipe; 16, opening and closing frame 1; 161, circular plate 1; 162, fan-shaped hole 1; 163, rotating column 1; 164, fan-shaped baffle 1; 17, opening and closing frame 2; 171, circular plate 2; 172, fan-shaped hole 2; 173, rotating column 2; 174, fan-shaped baffle 2; 18, linkage frame 1; 181, matching gear ring 1; 182, matching Gear; 183, matching circular plate 1; 184, tooth block 1; 185, linkage gear; 19, linkage frame 2; 2, reflux pipeline; 3, gas pump; 4, oxidation tower; 5, gas drive frame; 51, gas pipe; 52, rotating ring; 53, fan blade; 54, motor 1; 55, round head pipe; 6, control frame; 61, gear ring; 62, cylindrical gear; 63, bevel gear 1; 64, bevel gear 2; 65, driving gear 1; 66, driving gear 2; 41, transport pump; 7, water inlet; 71, distilled water inlet pipe; 72, annular groove; 73, connecting ring; 74, connecting pipe; 741, connecting rod; 75, fixed ring plate; 76, rotating ring plate; 8, delivery pump; 9, acid discharge pipe; 91, pH meter; 92, acid-resistant valve; 10, exhaust pipe; 101, high temperature resistant valve. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0039] See also Figure 1 , a low-energy consumption industrial nitric acid production process, comprising the following steps: S1, preparation of ammonia: first, liquid ammonia is sent to an ammonia evaporator, and after evaporating the ammonia gas, it is passed into an ammonia superheater for filtration to remove impurities.

[0040] S2. Oxidation of ammonia: After the filtered gaseous ammonia is mixed with air, it is heated in an oxidation tower 4 for catalytic oxidation to generate NOx.

[0041] S3. Absorption of nitrogen oxides: After the excess heat of the NOx gas is recovered, it is cooled and pressurized, and then the NOx gas is sent to the absorption tower 1 to be absorbed by water to generate dilute nitric acid. The small amount of NOx gas that has not reacted completely and the product NO gas are again introduced into the oxidation tower 4 for catalytic oxidation.

[0042] S4. Generation of concentrated nitric acid: The produced dilute nitric acid is passed into a concentration tower for concentration and cooling to generate concentrated nitric acid, which is then collected and stored.

[0043] See also Figure 1 , Figure 3 , Figure 5 and Figure 6 , wherein step S3 is completed by using a low-energy consumption industrial nitric acid production equipment, the production equipment includes an absorption tower 1, a reflux pipe 2 is fixedly installed on the left end of the upper side of the absorption tower 1, a gas pump 3 is fixedly connected to the end of the reflux pipe 2, the gas pump 3 is fixedly connected to the oxidation tower 4, a gas drive frame 5 is fixedly installed on the left end of the absorption tower 1, a control frame 6 is commonly provided between the gas drive frame 5 and the absorption tower 1, a transport pump 41 is fixedly connected between the gas drive frame 5 and the oxidation tower 4, a water inlet 7 is fixedly installed in the middle of the upper side of the absorption tower 1, a delivery pump 8 is fixedly installed on the upper end of the water inlet 7, an acid discharge pipe 9 is fixedly installed on the right end of the lower side of the absorption tower 1, an exhaust pipe 10 is fixedly installed on the upper right end of the absorption tower 1, and a A high temperature resistant valve 101, the structures of the absorption tower 1 and the oxidation tower 4 are both prior art; a No. 1 spray rack 11 is arranged inside the absorption tower 1 and located at the lower end of the water inlet member 7, a diverter pipe 12 slidingly penetrating the No. 1 spray rack 11 is fixedly installed in the middle of the lower end of the water inlet member 7, a No. 2 spray rack 13 is fixedly installed at the lower end of the diverter pipe 12, a fixed rod 14 is evenly fixedly installed on the inner wall of the absorption tower 1, and a condensation rack 15 is fixedly connected to the ends of the fixed rods 14, an opening and closing rack 1 16 is arranged on the inner ring wall of the absorption tower 1 and located on the upper side of the No. 2 spray rack 13, an opening and closing rack 2 17 is arranged on the inner ring wall of the absorption tower 1 and located on the upper side of the No. 1 spray rack 11, a linkage rack 1 18 is arranged on the opening and closing rack 16, and a linkage rack 2 19 is arranged on the opening and closing rack 2 17.

[0044] See also Figure 5 and Figure 6The gas transmission drive frame 5 includes a gas transmission pipe 51, the gas transmission pipe 51 is fixedly installed on the left end of the absorption tower 1, the inner end of the gas transmission pipe 51 is rotatably connected to a rotating ring 52, the inner ring wall of the rotating ring 52 is evenly fixedly installed with fan blades 53, the outer ring wall of the rotating ring 52 is fixedly installed with a ring gear, the outer ring wall of the gas transmission drive frame 5 is fixedly installed with a motor 1 54 through a motor seat, the output shaft of the motor 1 54 is fixedly installed with a spur gear meshing with the ring gear through a coupling, and the ends of the fan blades 53 are fixedly installed with a round head tube 55.

[0045] The process of nitrogen dioxide and water reacting to generate nitric acid and nitric oxide is expressed as: 3NO2+H2O=2HNO3+NO. However, since nitric acid will decompose at the same time, it can be regarded as a reversible reaction. Therefore, low temperature, high pressure and high nitrogen dioxide concentration as well as reducing the dilute nitric acid produced are all conducive to the balance moving towards the direction of generating nitric acid, thereby improving the absorption rate of nitrogen dioxide. Through the coordination of the gas transmission drive frame 5, the control frame 6, the linkage frame 1 18 and the linkage frame 2 19, while transporting NOx gas, the rotation of the No. 1 spray frame 11 and the No. 2 spray frame 13 is controlled, and the opening and closing of the opening and closing frame 16 and the opening and closing frame 2 17 are controlled. The No. 1 spray rack 11 cooperates with the No. 2 spray rack 13, so that when there is a large amount of nitrogen dioxide at the bottom of the absorption tower 1, there is more water to react with it, which promotes the reaction to proceed in the direction of the product. The absorption tower 1 is divided into three areas by the cooperation of the opening and closing rack 16 and the opening and closing rack 2 17. The first area is formed between the opening and closing rack 16 and the absorption tower 1, the second area is formed between the opening and closing rack 2 17 and the opening and closing rack 16 and the absorption tower 1, and the third area is formed between the opening and closing rack 2 17 and the absorption tower 1. In the initial stage, the opening and closing rack 16 is in an open state, and the opening and closing rack 2 17 is in a closed state. At this time, the nitrogen dioxide gas with gradually increasing concentration is in the first area and the second area. The water sprayed by the sprayer 111 and the sprayer 2 131 contacts and reacts in the area. Since the space is limited, the pressure in the space increases with the increase of nitrogen dioxide gas, further causing the reaction to proceed in the direction of the product. The product dilute nitric acid is discharged through the acid discharge pipe 9, reducing the content of the product dilute nitric acid. At the same time, driven by the gas transmission drive frame 5, the opening and closing frame 16 becomes a closed state, and the opening and closing frame 2 17 becomes an open state. At this time, a small amount of NOx gas that has not reacted completely and the product NO gas are sent to the oxidation tower 4 for catalytic oxidation through the reflux pipe 2 and the gas transmission pump 3 in the second area and the third area. NO continues to be introduced into the absorption tower 1. x gas reacts with the water mist sprayed from the sprayer 131. At this time, the NOx gas reacts in the first area. As the nitrogen dioxide gas increases, the air pressure increases, which promotes the reaction to proceed in the direction of the product. The product dilute nitric acid continues to be discharged through the acid discharge pipe 9 to reduce the content of the product. The opening and closing frame 16 cooperates with the opening and closing frame 2 17. Compared with the traditional absorption tower 1, the processing space is reduced while the time for NOx gas to stay in the absorption tower 1 is prolonged. At the same time, the pressure in the absorption tower 1 is increased, thereby promoting the forward reaction to proceed fully. When the reaction in the absorption tower is completed, the high temperature resistant valve 101 is opened to discharge the exhaust gas into the exhaust pipe 10.

[0046] See also Figure 2 , Figure 7 and Fig.11The condensation rack 15 includes a main spiral tube 151, the end of the fixing rod 14 is fixedly connected with the main spiral tube 151, the outer end of the main spiral tube 151 is evenly provided with a side spiral tube 153, the main spiral tube 151 and the side spiral tube 153 are fixedly connected by a support rod 152, the upper end of the main spiral tube 151 and the upper end of the side spiral tube 153 are fixedly installed with a drain pipe 154, the lower end of the main spiral tube 151 and the lower end of the side spiral tube 153 are fixedly installed with a water inlet pipe 155, the cross-sectional radius of the main spiral tube 151 is larger than the cross-sectional radius of the side spiral tube 153 and smaller than The cross-sectional diameter of the side spiral tube 153; the diameter of the circumscribed circle of the condensation rack 15 composed of the main spiral tube 151 and the side spiral tube 153 is equal to the sum of the diameter of the main spiral tube 151 and the diameter of the two side spiral tubes 153. According to the area and circumference calculation formula of a circle, compared with the circumscribed circle, the flow rate of condensed water is reduced through the main spiral tube 151 and the side spiral tube 153, while its contact area with the outside world is increased, thereby improving the condensation effect and reducing the heat generated by the reaction, so that the reaction tends to proceed in the direction of the product, thereby improving the reaction efficiency, so as to achieve the purpose of reducing energy consumption costs while improving reaction efficiency.

[0047] See also Figure 4 and Figure 6 The control frame 6 includes a gear ring 61, a gear ring 61 is fixedly installed on the right side of the outer ring wall of the rotating ring 52, a cylindrical gear 62 meshing with the gear ring 61 is rotatably connected to the inner end of the upper side of the gas delivery pipe 51, a bevel gear 1 63 is fixedly installed on the right end of the cylindrical gear 62 and located at the inner end of the upper side of the gas delivery pipe 51, a bevel gear 2 64 meshing with the bevel gear 1 63 is rotatably connected to the upper end of the gas delivery pipe 51, and the bevel gear 2 64 is rotatably connected to the absorption tower 1, and a driving gear 1 65 and a driving gear 2 66 are fixedly installed on the upper end of the bevel gear 2 64 from top to bottom, respectively, and the diameter of the driving gear 2 66 is larger than the diameter of the driving gear 1 65; the driving gear 1 65 and the driving gear 2 66 with different diameters ensure that the rotation cycles of the No. 1 spray rack 11 and the No. 2 spray rack 13 are different.

[0048] See also Figure 3 , Figure 4 , Figure 8 and Fig. 9The first spray rack 11 includes a sprayer 111, which is fixedly installed inside the absorption tower 1 and at the lower end of the water inlet 7. A driven gear ring 112 is fixedly installed on the outer ring wall of the sprayer 111, and the driven gear ring 112 is meshed with the driving gear 1 65. The second spray rack 13 includes a sprayer 2 131, a sprayer 2 131 is fixedly installed at the lower end of the shunt pipe 12, and a driven gear ring 2 132 is fixedly installed on the outer end of the sprayer 2 131, and the driven gear ring 2 132 is meshed with the driving gear 2 66. The structures of the sprayer 111 and the sprayer 2 131 are both prior arts; the driving gear 1 65 cooperates with the driving gear 2 66 to drive the sprayer 111 and the sprayer 2 131 to rotate while spraying. The contact area between the water droplets and the nitrogen oxide gas is increased dynamically, and the reaction efficiency is further improved. At the same time, the sprayer 111 and the sprayer 2 131 with different rotation speeds are used to avoid the overlap of the water mist they spray, thereby further increasing the contact area between the water droplets and the nitrogen oxide gas, so that the reaction tends to proceed in the direction of the product, and the reaction efficiency is improved. The rotation drive of the sprayer 111 and the sprayer 2 131 is provided by the power generated by the flow of the nitrogen oxide gas through the intake pipe, which further reduces the energy consumption in the reverse process. Through the cooperation of the sprayer 111 and the sprayer 2 131, the nitrogen dioxide in the first area of ​​the absorption tower 1 can react with more water when the initial nitrogen dioxide content is relatively high, thereby further causing the reaction to proceed in the direction of the product, and improving the reaction efficiency.

[0049] See also Fig.10 The water inlet member 7 includes a distilled water inlet pipe 71, which is fixedly installed on the middle part of the upper side of the absorption tower 1. The lower end of the distilled water inlet pipe 71 is provided with an annular groove 72, and a connecting ring 73 is rotatably connected in the annular groove 72. A connecting pipe 74 is fixedly installed on the lower end of the connecting ring 73. The lower end of the connecting pipe 74 slides through the opening and closing frame 17 and is fixedly connected to the No. 1 spray frame 11. A connecting rod 741 is evenly fixedly installed on the inner ring wall of the lower side of the connecting pipe 74, and the ends of the connecting rod 741 are fixed together. A fixed ring plate 75 is installed, and a rotating ring plate 76 is rotatably connected to the inner ring wall of the fixed ring plate 75. The lower end of the rotating ring plate 76 is fixedly connected to the shunt pipe 12. The lower end of the shunt pipe 12 slides through the No. 1 spray rack 11 and the opening and closing rack 16 and is finally fixedly connected to the No. 2 spray rack 13; the connecting pipe 74 is rotatably connected to the distilled water inlet pipe 71 to prevent interference with the rotation of the No. 1 spray rack 11, and the fixed ring plate 75 cooperates with the rotating ring plate 76 to prevent interference with the rotation of the No. 2 spray rack 13.

[0050] See also Figure 3 , Figure 4 and Fig. 9The opening and closing frame 16 includes a circular plate 161, which is fixedly installed on the inner ring wall of the absorption tower 1 and located on the upper side of the No. 2 spray rack 13. The circular plate 161 is evenly provided with fan-shaped holes 162. The upper end of the circular plate 161 is rotatably connected with a rotating column 163, and the rotating column 163 is rotatably connected to the diversion pipe 12. The outer end of the rotating column 163 is evenly fixed with a fan-shaped baffle 164. In the initial state, the fan-shaped baffle 164 and the fan-shaped hole 162 are staggered up and down; the opening and closing of the fan-shaped hole 162 is controlled by the rotation of the rotating column 163 and the fan-shaped baffle 164.

[0051] See also Figure 3 , Figure 4 , Figure 8 and Fig.10 The opening and closing frame 17 includes a circular plate 171, which is fixedly installed on the inner ring wall of the absorption tower 1 and located on the upper side of the No. 1 spray rack 11. The circular plate 171 is evenly provided with fan-shaped holes 172. The upper end of the circular plate 171 is rotatably connected with a rotating column 173, and the outer end of the rotating column 173 is evenly fixed with a fan-shaped baffle 174. In the initial state, the fan-shaped baffle 174 is aligned with the fan-shaped hole 172 up and down.

[0052] See also Figure 3 , Figure 4 and Fig. 9 The linkage frame 18 includes a matching gear ring 181, and all the fan-shaped baffles 164 are fixedly installed with a matching gear ring 181 at one end near the inner ring wall of the absorption tower 1. The upper end of the circular plate 161 is rotatably connected with a matching gear 182 that matches the matching gear ring 181. The upper end of the driving gear 266 and the left side of the matching gear ring 181 are rotatably connected with a matching circular plate 183. The right end of the matching circular plate 183 is fixedly installed with a tooth block 184. The lower end of the matching gear 182 slides through the circular plate 161 and is fixedly installed with a linkage gear Wheel 185, the linkage gear 185 cooperates with the tooth block 184, the number of tooth grooves on the linkage gear 185 is greater than the number of the fan-shaped baffle 164, and the structure of the linkage frame 19 is the same as the structure of the linkage frame 18; the fan-shaped baffle 164 is intermittently rotated by a tooth block 184, and because the number of tooth grooves on the linkage gear 185 is greater than the number of the fan-shaped baffle 164, the overlap or interlacing time between the fan-shaped baffle 164 and the fan-shaped hole 162 is extended, thereby extending the retention time of the NOx gas in the restricted area.

[0053] See also Fig.11A connecting pipe 1511 is fixedly connected between the drainage terminal pipe openings of the main spiral pipe 151 and the side spiral pipe 153. The terminal pipe openings of the main spiral pipe 151 and the side spiral pipe 153 are rotatably connected with an arc-shaped baffle 1512 through a pin shaft. A torsion spring 1513 is sleeved on the pin shaft. One end of the torsion spring 1513 is fixedly connected to the corresponding arc-shaped baffle 1512, and the other end of the torsion spring 1513 is fixedly connected to the corresponding main spiral pipe 151 or side spiral pipe 153. The end of the main spiral pipe 151 is connected to the end of the side spiral pipe 153 through the connecting pipe 1511. Only when the main spiral pipe 151 and the side spiral pipe 153 are filled with cooling water, all the arc-shaped baffles 1512 are opened to allow the cooling water to flow to the drainage pipe 154.

[0054] See also Figure 5 A pH meter 91 is fixedly installed at the left pipe opening of the acid discharge pipe 9, and an acid-resistant valve 92 is fixedly installed inside the acid discharge pipe 9; after ensuring that the concentration of the generated nitric acid reaches the requirement through the pH meter 91, the acid-resistant valve 92 is opened to discharge the nitric acid.

[0055] In the description of the present invention, it is necessary to understand that the terms "center", "middle", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "end", "axial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0056] In addition, the terms "first", "second", "number one", "number two", "one", "two" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the present invention, "multiple" means at least two, such as two, three, etc., unless otherwise clearly and specifically limited.

[0057] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "connect", "install", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, a sliding connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, all equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-energy consumption industrial nitric acid production process, characterized in that , including the following steps: S1. Preparation of ammonia: first, liquid ammonia is fed into an ammonia evaporator, and after evaporating the gaseous ammonia, it is passed into an ammonia superheater for filtration to remove impurities; S2, oxidation of ammonia: after filtering, the gaseous ammonia is mixed with air and heated in an oxidation tower (4) for catalytic oxidation, thereby generating NOx; S3, absorption of nitrogen oxides: After the excess heat of the NOx gas is recovered, cooled and pressurized, the NOx gas is sent to the absorption tower (1) to be absorbed by water to generate dilute nitric acid. The small amount of NOx gas that has not reacted completely and the product NO gas are again introduced into the oxidation tower (4) for catalytic oxidation; S4, generating concentrated nitric acid: the produced dilute nitric acid is passed into a concentration tower for concentration and cooling to generate concentrated nitric acid, which is then collected and stored; Step S3 is completed by using a low-energy consumption industrial nitric acid production equipment, the production equipment comprising an absorption tower (1), a reflux pipe (2) is fixedly installed at the left end of the upper side of the absorption tower (1), a gas pump (3) is fixedly connected to the end of the reflux pipe (2), the gas pump (3) is fixedly connected to the oxidation tower (4), a gas transmission drive frame (5) is fixedly installed at the left end of the absorption tower (1), a control frame (6) is commonly arranged between the gas transmission drive frame (5) and the absorption tower (1), a transport pump (41) is fixedly connected between the gas transmission drive frame (5) and the oxidation tower (4), a water inlet component (7) is fixedly installed at the middle part of the upper side of the absorption tower (1), a transport pump (8) is fixedly installed at the upper end of the water inlet component (7), an acid discharge pipe (9) is fixedly installed at the right end of the lower side of the absorption tower (1), an exhaust gas pipe (10) is fixedly installed at the upper right end of the absorption tower (1), and a high temperature resistant valve (101) is fixedly installed in the exhaust gas pipe (10); A No. 1 spray rack (11) is arranged inside the absorption tower (1) and located at the lower end of the water inlet member (7); a diverter pipe (12) is fixedly installed in the middle of the lower end of the water inlet member (7) and slides through the No. 1 spray rack (11); a No. 2 spray rack (13) is fixedly installed at the lower end of the diverter pipe (12); fixed rods (14) are evenly fixedly installed on the inner wall of the absorption tower (1); the ends of the fixed rods (14) are fixedly connected to a condensation rack (15); an opening and closing rack (16) is arranged on the inner ring wall of the absorption tower (1) and located on the upper side of the No. 2 spray rack (13); an opening and closing rack (2) is arranged on the inner ring wall of the absorption tower (1) and located on the upper side of the No. 1 spray rack (11); a linkage rack (18) is arranged on the opening and closing rack (16); and a linkage rack (19) is arranged on the opening and closing rack (17); The gas transmission drive frame (5) comprises a gas transmission pipe (51), the gas transmission pipe (51) is fixedly mounted on the left end of the absorption tower (1), the inner end of the gas transmission pipe (51) is rotatably connected to a rotating ring (52), the inner ring wall of the rotating ring (52) is evenly fixedly mounted with blades (53), the outer ring wall of the rotating ring (52) is fixedly mounted with a ring gear, the outer ring wall of the gas transmission drive frame (5) is fixedly mounted with a motor 1 (54) via a motor seat, the output shaft of the motor 1 (54) is fixedly mounted with a spur gear meshing with the ring gear via a coupling, and the ends of the blades (53) are commonly fixedly mounted with a round head tube (55).

2. A low-energy consumption industrial nitric acid production process according to claim 1, characterized in that: The condensation rack (15) comprises a main spiral tube (151), the ends of the fixing rods (14) are fixedly connected to the main spiral tube (151), the outer ends of the main spiral tube (151) are evenly provided with side spiral tubes (153), the main spiral tube (151) and the side spiral tubes (153) are fixedly connected via support rods (152), a drainage pipe (154) is fixedly installed on the upper ends of the main spiral tube (151) and the side spiral tubes (153), a water inlet pipe (155) is fixedly installed on the lower ends of the main spiral tube (151) and the side spiral tubes (153), and the cross-sectional radius of the main spiral tube (151) is greater than the cross-sectional radius of the side spiral tube (153) and smaller than the cross-sectional diameter of the side spiral tube (153).

3. A low-energy consumption industrial nitric acid production process according to claim 1, characterized in that: The control frame (6) comprises a gear ring (61), the gear ring (61) is fixedly mounted on the right side of the outer ring wall of the rotating ring (52), the cylindrical gear (62) meshing with the gear ring (61) is rotatably connected to the inner end of the upper side of the gas transmission pipe (51), a bevel gear (63) is fixedly mounted on the right end of the cylindrical gear (62) and located on the inner end of the upper side of the gas transmission pipe (51), a bevel gear (64) meshing with the bevel gear (63) is rotatably connected to the upper end of the gas transmission pipe (51), the bevel gear (64) is rotatably connected to the absorption tower (1), and a driving gear (65) and a driving gear (66) are fixedly mounted on the upper end of the bevel gear (64) from top to bottom, respectively, and the diameter of the driving gear (66) is larger than the diameter of the driving gear (65).

4. A low-energy consumption industrial nitric acid production process according to claim 3, characterized in that: The first spray rack (11) comprises a sprayer 1 (111), the sprayer 1 (111) is fixedly mounted inside the absorption tower (1) and located at the lower end of the water inlet member (7), a driven gear ring 1 (112) is fixedly mounted on the outer ring wall of the sprayer 1 (111), and the driven gear ring 1 (112) is meshed with the driving gear 1 (65), and the second spray rack (13) comprises a sprayer 2 (131), the sprayer 2 (131) is fixedly mounted on the lower end of the shunt pipe (12), a driven gear ring 2 (132) is fixedly mounted on the outer end of the sprayer 2 (131), and the driven gear ring 2 (132) is meshed with the driving gear 2 (66), and the structures of the sprayer 1 (111) and the sprayer 2 (131) are both prior art.

5. A low-energy consumption industrial nitric acid production process according to claim 1, characterized in that: The water inlet component (7) comprises a distilled water inlet pipe (71), which is fixedly installed in the middle of the upper side of the absorption tower (1), and an annular groove (72) is provided at the lower end of the distilled water inlet pipe (71), a connecting ring (73) is rotatably connected in the annular groove (72), a connecting pipe (74) is fixedly installed at the lower end of the connecting ring (73), and the lower end of the connecting pipe (74) slides through the second opening and closing frame (17) and is fixedly connected to the first spray frame (11), A connecting rod (741) is evenly fixedly installed on the inner ring wall at the lower side of the connecting pipe (74), a fixed ring plate (75) is commonly fixedly installed at the end of the connecting rod (741), the inner ring wall of the fixed ring plate (75) is rotatably connected to a rotating ring plate (76), the lower end of the rotating ring plate (76) is fixedly connected to the diverter pipe (12), and the lower end of the diverter pipe (12) slides through the No. 1 spray rack (11) and the opening and closing rack (16) and is finally fixedly connected to the No. 2 spray rack (13).

6. A low-energy consumption industrial nitric acid production process according to claim 1, characterized in that: The opening and closing frame (16) comprises a circular plate (161), which is fixedly mounted on the inner ring wall of the absorption tower (1) and located on the upper side of the second spray frame (13), and the circular plate (161) is evenly provided with fan-shaped holes (162). The upper end of the circular plate (161) is rotatably connected to a rotating column (163), and the rotating column (163) is rotatably connected to the diversion pipe (12). A fan-shaped baffle (164) is evenly fixedly mounted on the outer end of the rotating column (163). In an initial state, the fan-shaped baffle (164) and the fan-shaped hole (162) are staggered up and down.

7. A low-energy consumption industrial nitric acid production process according to claim 1, characterized in that: The second opening and closing frame (17) comprises a second circular plate (171), the second circular plate (171) is fixedly mounted on the inner ring wall of the absorption tower (1) and located on the upper side of the first spray frame (11), the second circular plate (171) is evenly provided with second fan-shaped holes (172), the upper end of the second circular plate (171) is rotatably connected with a second rotating column (173), the outer end of the second rotating column (173) is evenly fixedly mounted with a second fan-shaped baffle (174), and in an initial state, the second fan-shaped baffle (174) is aligned with the second fan-shaped hole (172) in the upper and lower directions.

8. A low-energy consumption industrial nitric acid production process according to claim 6, characterized in that: The linkage frame 1 (18) comprises a matching gear ring 1 (181), all the fan-shaped baffles 1 (164) are fixedly mounted with a matching gear ring 1 (181) at one end close to the inner ring wall of the absorption tower (1), the upper end of the circular plate 1 (161) is rotatably connected with a matching gear (182) that matches the matching gear ring 1 (181), the upper end of the driving gear 2 (66) and located on the left side of the matching gear ring 1 (181) is rotatably connected with a matching circular plate 1 (183), the right end of the matching circular plate 1 (183) is fixedly mounted with a gear block 1 (184), the lower end of the matching gear (182) slides through the circular plate 1 (161) and is fixedly mounted with a linkage gear (185), the linkage gear (185) matches with the gear block 1 (184), and the structure of the linkage frame 2 (19) is the same as that of the linkage frame 1 (18).

9. A low-energy consumption industrial nitric acid production process according to claim 2, characterized in that: A connecting pipe (1511) is fixedly connected between the drainage terminal pipe openings of the main spiral pipe (151) and the side spiral pipe (153); the terminal pipe openings of the main spiral pipe (151) and the side spiral pipe (153) are rotatably connected to an arc-shaped baffle plate (1512) via a pin shaft; a torsion spring (1513) is sleeved on the pin shaft; one end of the torsion spring (1513) is fixedly connected to the corresponding arc-shaped baffle plate (1512); and the other end of the torsion spring (1513) is fixedly connected to the corresponding main spiral pipe (151) or the side spiral pipe (153).

10. A low-energy consumption industrial nitric acid production process according to claim 1, characterized in that: A pH meter (91) is fixedly installed at the left pipe opening of the acid discharge pipe (9), and an acid-resistant valve (92) is fixedly installed inside the acid discharge pipe (9).

Images