An apparatus for directly preparing phosphoric acid from high-purity phosphorus vapor

Abstract

The utility model discloses a kind of equipment for high-purity phosphorus vapor direct preparation phosphoric acid, including combustion tower, hydration tower and dilute acid tower, the combustion tower is connected with high-purity phosphorus vapor pipeline, compressed air pipeline, the combustion tower and hydration tower top are connected by phosphorus pentoxide gas guide pipe, the hydration tower bottom is connected with dilute acid tower top by pipeline;The utility model is fully combusted by high-purity phosphorus vapor and compressed air into combustion tower, obtains phosphorus pentoxide gas, enters hydration tower and fully fuses using the atomizing property of helical spray head, good, good spray effect advantage, maximum degree makes phosphorus pentoxide gas dissolve in pure water and form phosphoric acid, recovery effect is good, and the equipment structure is simple, and land area is small.

Description

Technical Field

[0001] This utility model relates to the field of phosphorus vapor acid production, specifically a device for the direct preparation of phosphoric acid from high-purity phosphorus vapor. Background Technology

[0002] Phosphoric acid is an important chemical intermediate and a common raw material for synthesizing most phosphates and some phosphoric acid esters and other phosphorus-containing compounds. It is widely used in the food, pharmaceutical, electronics, petroleum, metallurgy and chemical industries.

[0003] Depending on the production process, phosphoric acid can be obtained from wet-process phosphoric acid and thermal-process phosphoric acid. Wet-process phosphoric acid is produced by reacting a strong acid—usually sulfuric acid, but also nitric acid, hydrochloric acid, or fluorosilicic acid—with phosphate rock in a double decomposition reaction to obtain crude phosphoric acid containing many impurities, generally used in fertilizers. After purification, this phosphoric acid can be obtained as food-grade phosphoric acid. Thermal-process phosphoric acid is produced by reducing phosphate rock with carbon at high temperatures to obtain yellow phosphorus. In actual production, yellow phosphorus is burned in a combustion furnace to produce phosphorus pentoxide gas, which is then piped to an absorption tower for water mist spraying. Phosphorus pentoxide reacts with water to form phosphoric acid. However, because there is no filtration system in the pipelines, unburned yellow phosphorus or impurities from the yellow phosphorus are carried into the absorption tower along with the phosphorus pentoxide gas. This results in low purity phosphoric acid containing impurities that are difficult to remove, leading to a decline in product quality. Before the widespread adoption of wet-process phosphoric acid purification technology, it was almost the sole raw material for refined phosphate products. From a process flow perspective, compared to thermal phosphoric acid, wet phosphoric acid has a longer and more complex process flow, with more unit operations and supporting facilities. However, in terms of economy, wet phosphoric acid has a significant advantage over thermal phosphoric acid. One important reason for the high cost of thermal phosphoric acid is the high energy consumption during production, and the traditional thermal phosphoric acid production process is crude in terms of salt content. Utility Model Content

[0004] The purpose of this invention is to provide an apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: An apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor includes a combustion tower, a hydration tower, and a dilute acid tower. The combustion tower is connected to a high-purity phosphorus vapor pipeline and a compressed air pipeline. The tops of the combustion tower and the hydration tower are connected via a phosphorus pentoxide gas conduit. The bottom of the hydration tower is connected to the top of the dilute acid tower via a pipeline.

[0006] The combustion tower is fixedly equipped with a high-purity phosphorus vapor inlet pipe and a compressed air inlet pipe at its outer end, which are connected to the lower part of the combustion tower. A fixed thermometer b is installed at the connection point. A cooling water tank is installed at the top of the combustion tower, and a cooling water jacket is installed around it. The cooling water tank supplies water to the cooling water jacket. A fixed thermometer a is installed on the connecting pipe between the combustion tower and the hydration tower. A circulating water outlet and a sewage outlet are installed at the bottom of the combustion tower.

[0007] As a further embodiment of this utility model: a demister is fixedly provided at the top of the hydration tower, and the demister has three layers of mesh; an acid inlet, an overflow weir acid inlet, and an acid spraying port are fixedly provided at the top of the hydration tower, and a spiral spray head is fixedly provided at the acid spraying port; an upper cooling water outlet is provided at the top of the hydration tower, an upper cooling water inlet and a lower cooling water outlet are provided in the middle, and a circulating acid outlet, a lower cooling water inlet, and a drain outlet are provided at the bottom.

[0008] As a further embodiment of this utility model: a gas outlet is fixedly provided at the top of the dilute acid tower, and a pure water inlet, a dilute acid inlet, and a pressure measuring point b are fixedly provided at the top; a connecting pipe is provided inside the dilute acid tower, which extends from the top to the bottom of the dilute acid tower, a Venturi scrubber is fixedly provided in the middle, connected to a DN dilute acid pipe, and a gas inlet is fixedly provided at the tail; a dilute acid outlet and a liquid level gauge port are fixedly provided at the bottom of the dilute acid tower.

[0009] As a further improvement of this invention: the thermometer b has a measuring range of 0-2000℃, and the thermometer a has a measuring range of 0-1000℃. As a further improvement of this utility model: the pressure measuring point b is detected by a U-shaped pressure gauge with a range of ±3kPa and a length of 2 meters.

[0010] As a further improvement of this invention: the spray angle of the acid spray nozzle is ≥60°. As a further embodiment of this utility model: a phosphorus combustion nozzle is fixedly provided at the bottom of the combustion tower, and a swirl guide leaf is provided inside the phosphorus combustion nozzle. The swirl guide leaf consists of four parts, all distributed on the gas injection pipe. The swirl guide leaf is spiral in shape. The radial spiral angle of each swirl guide leaf is degrees. The length of the swirl guide leaf along the axial direction of the gas injection pipe is 200mm. The air enters the burner in a tangential swirl, and the spiral direction of the swirl guide leaf is consistent with the rotation direction of the air.

[0011] As a further embodiment of this utility model: the Venturi scrubber includes a converging section of the Venturi scrubber, the inlet of the converging section of the Venturi scrubber is sealed and welded to the connecting pipe at the bottom of the hydration tower, and the outlet of the Venturi scrubber is sealed and welded to the gas inlet at the top of the dilute acid tower; one end of the dilute acid pipe is connected to the dilute acid injection port at the throat of the Venturi scrubber, and the other end is connected to the dilute acid inlet of the dilute acid tower. Compared with the prior art, the beneficial effects of this utility model are: 1. This utility model uses high-purity phosphorus vapor and compressed air to enter a combustion tower for complete combustion, resulting in phosphorus pentoxide gas. The gas then enters a hydration tower and utilizes the advantages of good atomization and spraying effect of the spiral spray head to fully integrate the phosphorus pentoxide gas into pure water to the maximum extent, forming phosphoric acid. This results in good recovery effect, and the equipment has a simple structure and small footprint.

[0012] 2. This utility model has high phosphorus vapor purity during the recycling process, with almost no CO, dust, S gas, or phosphorus mud, and does not require dust removal or desulfurization equipment, making it more green and environmentally friendly. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of a device for the direct preparation of phosphoric acid from high-purity phosphoric acid vapor.

[0015] Figure 2 This is a schematic diagram of the phosphorus combustion nozzle in an apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor.

[0016] Figure 3 This is a schematic diagram of the structure of AA in an apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor.

[0017] Figure 4 This is a schematic diagram of the main structure of a single swirl guide leaf after installation in an apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor.

[0018] Figure 5 This is a top view of the structure of a single swirl guide vane after installation in an apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor.

[0019] Figure 6 This is a schematic diagram of the structure of a Chinese Churley scrubber, an apparatus for the direct preparation of phosphoric acid from high-purity phosphoric acid vapor.

[0020] In the diagram: 1. Combustion tower; 2. Hydration tower; 3. Dilute acid tower; 4. Cooling water tank; 5. Demister; 6. Venturi scrubber; 7. Connecting pipe a; 8. Connecting pipe b; 9. Phosphorus combustion nozzle; 10. Swirl guide vane; 11. Convergence section of Venturi scrubber; 12. Throat of Venturi scrubber; 13. Divergence section of Venturi scrubber; 101. Circulating water outlet; 102. Drain outlet; 201. Circulating acid outlet; 202. Acid inlet; 203. Acid spray nozzle; 204. Lower section cooling water inlet; 205. 1. Lower cooling water outlet; 206. Upper cooling water inlet; 207. Upper cooling water outlet; 208. Overflow weir acid inlet; 209. Sewage outlet; 301. Pure water inlet; 302. Dilute acid inlet; 303. Dilute acid outlet; 304. Gas inlet; 305. Gas outlet; 306. Level gauge port; 401. Cool water layer; 501. High-purity phosphorus vapor inlet; 502. Compressed air inlet; 801. Thermometer a; 802. Thermometer b; 901. Pressure measuring point a; 902. Pressure measuring point b. Detailed Implementation

[0021] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Please see Figures 1-3In this embodiment of the present invention, an apparatus for directly preparing phosphoric acid from high-purity phosphorus vapor includes a combustion tower 1, a hydration tower 2, and a dilute acid tower 3. A high-purity phosphorus vapor inlet 501 and a compressed air inlet 502 are fixedly installed at the bottom of the combustion tower 1. The high-purity phosphorus vapor and compressed air enter the combustion tower 1, mix and burn completely to form phosphorus pentoxide gas. A thermometer b802 is fixedly installed at the bottom of the combustion tower 1 to detect the temperature inside the combustion tower 1. The combustion tower 1 and the hydration tower 2 are connected by a connecting pipe 7, and a thermometer a801 is fixedly installed on the connecting pipe 7 to detect the temperature of the connecting pipe, which must reach above 400°C. It should be further explained that the combustion tower 1 is fixedly provided with a cooling water tank 4 at the top, and a cooling water layer 401 is fixedly provided around the combustion tower 1. The cooling water tank 4 supplies water to the cooling water layer 401, and the cooling water layer 401 cools the combustion tower 1. A circulating water outlet 101 is fixedly provided at the bottom of the combustion tower 1, and the circulating water outlet 101 is connected to a circulating water tank. In this utility model, it should be further explained that the phosphorus pentoxide gas formed in the combustion tower 1 enters from the top of the hydration tower 2 through the connecting pipe 7. The top of the hydration tower 2 is fixedly provided with an acid inlet 209, an overflow weir acid inlet 208, and an acid spray nozzle 203. The top of the acid spray nozzle 203 is a spiral spray head. The top of the hydration tower 2 is fixedly provided with an upper cooling water outlet 207, an upper cooling water inlet 206, and a lower cooling water outlet 205. The bottom of the hydration tower 2 is fixedly provided with a circulating acid outlet 201 and a lower cooling water inlet 204. In this utility model, a demister 5 is fixedly installed at the top of the hydration tower 2. The bottom of the hydration tower 2 and the top of the dilute acid tower 3 are connected by a connecting pipe 8. The connecting pipe 8 enters the dilute acid tower 3 from the top and extends to the bottom of the dilute acid tower 3. A pressure measuring point a901 is fixedly installed on the connecting pipe 8. A Venturi scrubber 6 is fixedly installed in the middle of the connecting pipe 8. A gas inlet 304 is fixedly installed at the bottom of the connecting pipe 8. A gas outlet 305 is fixedly installed at the top of the dilute acid tower 3. The gas outlet 305 is connected to the demister 5. A pure water inlet 301 is fixedly installed at the top of the dilute acid tower 3. A dilute acid inlet 302 is fixedly installed at the top of the dilute acid tower 3. A pressure measuring point b902 is fixedly installed at the top of the dilute acid tower 3. The pressure measuring point is detected by a U-shaped pressure gauge. A level gauge port 306 is fixedly installed at the bottom of the dilute acid tower 3. A dilute acid outlet 303 is fixedly installed at the bottom of the dilute acid tower 3.

[0025] In this utility model, it should be further explained that a phosphorus combustion nozzle 9 is fixedly provided at the bottom of the combustion tower 1, and a swirl guide leaf 10 is provided inside the phosphorus combustion nozzle 9. The swirl guide leaf 10 consists of four parts, which are distributed on the gas injection pipe. The swirl guide leaf 10 is spiral in shape. The radial spiral angle of each swirl guide leaf 10 is 120 degrees. The length of the swirl guide leaf 10 along the axial direction of the gas injection pipe is 200 mm. The air enters the burner in a tangential swirl, and the spiral direction of the swirl guide leaf 10 is consistent with the rotation direction of the air.

[0026] It should be further explained that the Venturi scrubber 6 includes a converging section 11. The inlet of the converging section 11 is sealed and welded to the connecting pipe 8 at the bottom of the hydration tower 2, and the outlet of the Venturi scrubber is sealed and welded to the gas inlet 304 at the top of the dilute acid tower 3. One end of the dilute acid pipe is connected to the dilute acid injection port 4 at the throat 12 of the Venturi scrubber, and the other end is connected to the dilute acid inlet 302 of the dilute acid tower 3. When the gas enters the Venturi scrubber, it is accelerated in the converging section, and a negative pressure is formed at the throat. The gas is drawn in and forms high-speed atomized droplets, which are fully mixed with the gas and then enter the diffusion section to decelerate, thereby achieving efficient capture of impurities.

[0027] In the preparation of phosphoric acid, high-purity phosphorus vapor and compressed air are first introduced into combustion tower 1 through the inlet pipe at the bottom of combustion tower 1 in a certain ratio. Within combustion tower 1, phosphorus pentoxide gas is fully combusted to generate phosphorus pentoxide gas. During combustion, the temperature is monitored in real time by thermometer b802 to ensure complete combustion. The generated phosphorus pentoxide gas enters hydration tower 2 through connecting pipe 7. Simultaneously, acid solution is added from the acid inlet 202 and overflow weir acid inlet 208 at the top of hydration tower 2. The acid solution is atomized and sprayed out through the spiral spray head of acid spray nozzle 203, ensuring full contact with the phosphorus pentoxide gas, which dissolves in water to form phosphoric acid. During this process, the temperature inside hydration tower 2 is controlled by the upper cooling water inlet 206, upper cooling water outlet 207, lower cooling water inlet 204, and lower cooling water outlet 205 to ensure the reaction proceeds at the optimal temperature. The generated phosphoric acid solution is discharged from the circulating acid outlet 201 at the bottom of hydration tower 2 and enters dilute acid tower 3 through connecting pipe 8. Inside the dilute acid tower 3, pure water and dilute acid are introduced through the pure water inlet 301 and dilute acid inlet 302 respectively to further wash and absorb the gas. The Venturi scrubber 6 in the middle of the connecting pipe 8 enhances the washing effect. Finally, the phosphoric acid product is discharged from the dilute acid outlet 303 at the bottom of the dilute acid tower 3, and the gas is discharged through the gas outlet 305 and further treated by the demister 5.

[0028] It should be noted that this utility model is a device for the direct preparation of phosphoric acid from high-purity phosphorus vapor. All parts are general standard parts or components known to those skilled in the art. Its structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0029] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0030] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor, characterized in that, It includes a combustion tower (1), a hydration tower (2) and a dilute acid tower (3). The combustion tower (1) is connected to a high-purity phosphorus vapor pipeline and a compressed air pipeline. The tops of the combustion tower (1) and the hydration tower (2) are connected by a phosphorus pentoxide gas conduit. The bottom of the hydration tower (2) is connected to the top of the dilute acid tower (3) by a pipeline.

2. The apparatus for directly preparing phosphoric acid from high-purity phosphoric acid vapor according to claim 1, characterized in that, The combustion tower (1) is fixedly provided with a high-purity phosphorus vapor inlet pipe (501) and a compressed air inlet pipe (502) at its outer end. The two are connected to the lower part of the combustion tower (1), and a fixed thermometer b (802) is provided at the connection point. The top of the combustion tower (1) is provided with a cooling water tank (4), and a cooling water jacket (401) is provided around it. The cooling water tank (4) supplies water to the cooling water jacket (401). A fixed thermometer a (801) is provided on the connecting pipe (7) between the combustion tower (1) and the water tower (2). The bottom of the combustion tower (1) is provided with a circulating water outlet (101) and a sewage outlet (102).

3. The apparatus for directly preparing phosphoric acid from high-purity phosphoric acid vapor according to claim 1, characterized in that, The top of the hydration tower (2) is fixedly equipped with a demister (5), which has three layers of mesh. The top of the hydration tower (2) is fixedly equipped with an acid inlet (202), an overflow weir acid inlet (208), and an acid spraying port (203), and the acid spraying port (203) is fixedly equipped with a spiral spray head. The top of the hydration tower (2) is equipped with an upper cooling water outlet (207), the middle section is equipped with an upper cooling water inlet (206) and a lower cooling water outlet (205), and the bottom is equipped with a circulating acid outlet (201), a lower cooling water inlet (204), and a drain outlet (209).

4. The apparatus for directly preparing phosphoric acid from high-purity phosphoric acid vapor according to claim 1, characterized in that, The dilute acid tower (3) is fixedly provided with a gas outlet (305) at the top, a pure water inlet (301), a dilute acid inlet (302) and a pressure measuring point b (902) at the top; the dilute acid tower (3) is provided with a connecting pipe (8) inside, which extends from the top of the dilute acid tower (3) to the bottom, a Venturi scrubber (6) is fixedly provided in the middle, connected to a DN25 dilute acid pipe, and a gas inlet (304) is fixedly provided at the tail; the dilute acid tower (3) is fixedly provided with a dilute acid outlet (303) and a liquid level gauge port (306) at the bottom.

5. The apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor according to claim 2, characterized in that, The thermometer b (802) has a range of 0-2000℃, and the thermometer a (801) has a range of 0-1000℃.

6. The apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor according to claim 4, characterized in that, The pressure measuring point b (902) is detected by a U-shaped pressure gauge with a range of ±3kPa and a length of 2 meters.

7. The apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor according to claim 3, characterized in that, The spray angle of the acid spray nozzle (203) is ≥60°.

8. The apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor according to claim 1, characterized in that, The combustion tower (1) is fixedly provided with a phosphorus combustion nozzle (9) at the bottom. The phosphorus combustion nozzle (9) is provided with a swirl guide (10) inside. The swirl guide (10) consists of four parts, which are distributed on the gas nozzle. The swirl guide (10) is spiral in shape. The radial spiral angle of each swirl guide (10) is (120) degrees. The length of the swirl guide (10) along the axial direction of the gas nozzle is 200 mm. The air enters the burner in a tangential swirl. The spiral direction of the swirl guide (10) is consistent with the rotation direction of the air.

9. The apparatus for the direct preparation of phosphoric acid from high-purity phosphorus vapor according to claim 4, characterized in that, The Venturi scrubber (6) includes a converging section (11) of the Venturi scrubber. The inlet of the converging section (11) of the Venturi scrubber is sealed and welded to the connecting pipe (8) at the bottom of the hydration tower (2). The outlet of the Venturi scrubber is sealed and welded to the gas inlet (304) at the top of the dilute acid tower (3). One end of the dilute acid pipe is connected to the dilute acid injection port (4) of the throat (12) of the Venturi scrubber, and the other end is connected to the dilute acid inlet (302) of the dilute acid tower (3).

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