A phosphorus pentoxide and hot process phosphoric acid co-production system
Patent Information
- Application Number
- CN202522625861.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-11
- Publication Date
- 2026-09-25
- Estimated Expiration
- 2035-12-11
AI Technical Summary
目前，利用五氧化二磷联合生产热法磷酸的工艺系统主要是将黄磷燃烧产生的P2O5烟气送入到水合反应器内，利用去离子水与P2O5烟气进行气液接触反应，在进行气液反应接触的过程中就能够生产磷酸产品，上述的系统虽然能够实现热法磷酸的生产，但是在生产的过程中存在以下的不足：一是P2O5烟气与去离子水在气液接触的过程中，气液接触的面积小、时间短，不能实现P2O5烟气与去离子水的充分接触，P2O5烟气不能与去离子水进行充分的反应，不能对P2O5烟气中的磷进行充分的回收，会造成P2O5烟气磷的浪费，导致磷酸的产品质量不理想；二是由于P2O5烟气与去离子水的反应是放热反应，P2O5烟气与去离子水进行反应的过程中，不能实现对反应温度的精确控制，会存在P2O5烟气与去离子反应过程中反应温度不稳定的情况，进而会影响系统的稳定的运行
[0005]与现有的技术相比,本系统的优点在于：一是本装置优化了水合反应塔的内部结构，在水合反应塔内设置了相应的进气分布器、填料层、液体分布器和丝网除沫器，设置的进气分布器能够让混合尾气均匀的分布到水合反应塔内，设置的液体分布器能够将去离子水均匀的送入到水合反应塔内，均匀分布在水合反应塔内的与去离子水就能够在填料层内进行充分的接触反应，让混合尾气中的磷充分的溶解在去离子水中形成磷酸，本系统设置的水合反应塔能够增大气液接触的面积，延长气液接触的时间，提高去离子水对混合尾气的吸收效率，便于提高磷酸的产量；二是本系统对水合反应塔磷酸循环过程的温度和浓度进行合理的控制，设置的缓冲罐可以对水合反应产生的磷酸进行回收，设置的浓度检测仪可以对缓冲罐内的磷酸浓度进行适时的检测，符合浓度要求的磷酸经过第二冷却器冷却处理后进入到磷酸储罐内，不符合浓度要求的磷酸则经过第一冷却器的冷却处理后进入到水合反应塔内进行再一次的气液反应，本系统中设置的第一冷却器可以控制进入到水合反应塔内的磷酸的温度，通过对进入到水合反应塔内磷酸温度的调节，可以保证气液反应的温度稳定，本装置通过对水反应塔内温度和浓度的调节，不仅能够保证生产的磷酸浓度温度，提高磷酸的生产质量，而且能够保证系统反应过程中的温度稳定，能够有效的保证系统的稳定成产，本装置具有结构布置合理、运行效果好的优点，易于推广使用。
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Figure CN224793489U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of phosphorus chemical production technology, specifically relating to a co-production system of phosphorus pentoxide and thermal phosphoric acid. Background Technology
[0002] Phosphorus pentoxide and thermal phosphoric acid are two important phosphorus chemical products. Traditionally, their production is carried out separately. The phosphorus pentoxide production process involves burning elemental yellow phosphorus in air to generate P2O5 flue gas, which is then cooled and collected to obtain a white powder or flake product. The thermal phosphoric acid production process involves passing the P2O5 flue gas generated from the combustion of yellow phosphorus into water or dilute phosphoric acid for hydration absorption to obtain phosphoric acid. The core idea of the co-production system of phosphorus pentoxide and thermal phosphoric acid is to organically integrate these two processes, utilizing the same yellow phosphorus combustion unit, and through precise process control and energy and material management, simultaneously producing both products. This not only improves resource utilization but also significantly reduces energy consumption and production costs. Currently, the process system for producing thermal phosphoric acid using phosphorus pentoxide mainly involves feeding the P2O5 flue gas generated from the combustion of yellow phosphorus into a hydration reactor. Deionized water then reacts with the P2O5 flue gas in a gas-liquid contact reaction, producing phosphoric acid during this process. While this system can achieve thermal phosphoric acid production, it has the following shortcomings: First, the gas-liquid contact area between the P2O5 flue gas and deionized water is small and the contact time is short, failing to achieve sufficient contact and reaction. This prevents adequate phosphorus recovery from the P2O5 flue gas, resulting in phosphorus waste and suboptimal phosphoric acid quality. Second, because the reaction between P2O5 flue gas and deionized water is exothermic, precise temperature control is impossible, leading to temperature instability and affecting the stable operation of the system. Therefore, it is an objective need to develop a co-production system of phosphorus pentoxide and thermal phosphoric acid with a reasonable structural layout that can improve product quality and ensure stable system operation. Summary of the Invention
[0003] The purpose of this invention is to provide a co-production system of phosphorus pentoxide and thermal phosphoric acid with a reasonable structural layout that can improve product quality and ensure stable system operation.
[0004] The purpose of this utility model is achieved as follows: it includes a gas collection pipe and a hydration reaction tower. Inside the hydration reaction tower, from bottom to top, an air inlet distributor, a packing layer, a liquid distributor, and a wire mesh demister are installed at intervals. The gas collection pipe is connected to the air inlet distributor, and the liquid distributor is connected to the water supply pipe. A water supply valve is installed on the water supply pipe. An exhaust pipe is installed at the top of the hydration reaction tower, and a buffer tank is connected to the bottom of the hydration reaction tower via a drain pipe. A liquid outlet pipe is installed at the bottom of the buffer tank, and a circulation pump and a concentration detector are installed sequentially on the liquid outlet pipe. A T-joint is installed at the end of the liquid outlet pipe. A circulation pipe connected to the water supply pipe is installed at one outlet of the T-joint, and a circulation control valve and a first cooler are installed sequentially on the circulation pipe. An acid discharge pipe is connected to the other outlet of the T-joint, and an acid discharge valve, a second cooler, and a phosphoric acid storage tank are installed sequentially on the acid discharge pipe.
[0005] Compared with existing technologies, the advantages of this system are as follows: First, this device optimizes the internal structure of the hydration reaction tower. It incorporates a corresponding air inlet distributor, packing layer, liquid distributor, and wire mesh demister. The air inlet distributor ensures uniform distribution of the mixed tail gas within the hydration reaction tower, while the liquid distributor uniformly introduces deionized water. This uniform distribution allows for sufficient contact and reaction between the gas and deionized water within the packing layer, enabling the phosphorus in the mixed tail gas to fully dissolve in the deionized water to form phosphoric acid. The hydration reaction tower in this system increases the gas-liquid contact area and prolongs the contact time, improving the absorption efficiency of deionized water on the mixed tail gas and facilitating increased phosphoric acid production. Second, this system provides reasonable control over the temperature and concentration of phosphoric acid during the hydration reaction tower's phosphoric acid circulation process. The included buffer tank can regulate the water... Phosphoric acid produced in the reaction is recovered. A concentration detector is installed to monitor the phosphoric acid concentration in the buffer tank in real time. Phosphoric acid that meets the concentration requirements is cooled by a second cooler and then enters the phosphoric acid storage tank. Phosphoric acid that does not meet the concentration requirements is cooled by a first cooler and then enters the hydration reaction tower for another gas-liquid reaction. The first cooler in this system can control the temperature of the phosphoric acid entering the hydration reaction tower. By adjusting the temperature of the phosphoric acid entering the hydration reaction tower, the temperature of the gas-liquid reaction can be kept stable. This device, by regulating the temperature and concentration in the hydration reaction tower, can not only ensure the concentration and temperature of the produced phosphoric acid and improve the production quality of phosphoric acid, but also ensure the temperature stability of the system reaction process, effectively ensuring the stable production of the system. This device has the advantages of reasonable structural layout, good operation effect, and is easy to promote and use. Attached Figure Description
[0006] Figure 1 This is a schematic diagram of the overall structure of this utility model; In the diagram: 1-Gas collection pipe, 2-Hydration reaction tower, 21-Gas inlet distributor, 211-Main gas inlet pipe, 212-Branch distribution pipe, 213-Blind flange, 214-Distribution cone cap, 215-Bypass pipe, 22-Packing layer, 23-Liquid distributor, 231-Main liquid inlet pipe, 232-Upper liquid distribution pipe, 233-Lower liquid distribution pipe, 234-Upper spray head, 235-Lower spray head, 236-Straight pipe, 237-Upper... 238-Lower connecting pipe, 24-Wire mesh demister, 25-Exhaust pipe, 3-Water supply pipe, 4-Drain pipe, 5-Buffer tank, 51-Level gauge, 52-Thermometer, 53-Spiral coil, 54-Media inlet, 55-Media outlet, 6-Discharge pipe, 7-Concentration detector, 8-T-connector, 9-Circulation pipe, 10-First cooler, 11-Acid discharge pipe, 12-Second cooler, 13-Phosphoric acid storage tank. Detailed Implementation
[0007] The present invention will be further described below with reference to the accompanying drawings, but this description is not intended to limit the present invention in any way. Any changes or improvements made based on the teachings of the present invention shall fall within the protection scope of the present invention.
[0008] like Figure 1As shown, this utility model includes a gas collection pipe 1 and a hydration reaction tower 2. Inside the hydration reaction tower 2, from bottom to top, are sequentially installed an air inlet distributor 21, a packing layer 22, a liquid distributor 23, and a wire mesh demister 24. The packing layer 22 has a structure used in the prior art, mainly including a grid structure and packing material. The packing material can be PP absorbent packing, which is stacked in a random manner. The grid is also supported by PP grid. The packing layer 22 has advantages such as large specific surface area, high absorption efficiency, and low pressure drop. The wire mesh demister 24 uses one or a combination of two or three of the following: an S-shaped hooked baffle plate, random packing, and wire mesh, as used in the prior art. It has advantages such as gradient demisting, high efficiency, and low pressure drop; the collecting gas pipe 1 is connected to the inlet distributor 21, and the liquid distributor 23 is connected to the water supply pipe 3. A water supply valve is installed on the water supply pipe 3. An exhaust pipe 25 is set at the top of the hydration reaction tower 2. The inlet distributor 21 can evenly distribute the P2O5 flue gas into the hydration reaction tower 2, and the liquid distributor 23 can evenly feed deionized water into the hydration reaction tower 2. The P2O5 flue gas and deionized water evenly distributed in the hydration reaction tower 2 can fully contact and react in the packing layer 22, allowing the phosphorus in the P2O5 flue gas to fully dissolve in the deionized water to form phosphoric acid. The hydration reaction tower 2, with its integrated design, increases the gas-liquid contact area and prolongs the contact time, allowing the P2O5 flue gas to fully react with deionized water, thereby improving the phosphorus recovery rate from the P2O5 flue gas and increasing the yield of phosphoric acid. A buffer tank 5 is connected to the bottom of the hydration reaction tower 2 via a drain pipe 4. An outlet pipe 6 is installed at the bottom of the buffer tank 5, and a circulation pump and a concentration detector 7 are sequentially installed on the outlet pipe 6. The concentration detector 7 is a pre-existing instrument for detecting acid concentration; a finished product can be directly purchased according to usage requirements. The buffer tank 5 can recover the phosphoric acid produced by the hydration reaction, and the concentration detector 7 can... The phosphoric acid concentration in the buffer tank is monitored in a timely manner. A three-way connector 8 is installed at the end of the outlet pipe 6. A circulation pipe 9 connected to the water supply pipe 3 is installed on one outlet of the three-way connector 8. A circulation control valve and a first cooler 10 are installed sequentially on the circulation pipe 9. An acid discharge pipe 11 is connected to the other outlet of the three-way connector 8. An acid discharge valve, a second cooler 12 and a phosphoric acid storage tank 13 are installed sequentially on the acid discharge pipe 11. The water supply valve, circulation control valve and acid discharge valve used in this system are all solenoid valves used in the prior art. The first cooler 10 and the second cooler 12 are water-cooled coolers or air-cooled coolers used in the prior art.
[0009] The working process of this system is as follows: The P2O5 flue gas generated by the combustion of phosphorus pentoxide mixes with the tail gas after cold precipitation and crystallization to form a mixed tail gas. The mixed tail gas is sent into the gas distributor 21 through the gas collection pipe 1. The gas distributor 21 then evenly distributes the mixed tail gas into the hydration reaction tower 2. After that, the water supply valve is opened, and deionized water is introduced into the liquid distributor 23 through the water supply pipe 3. After being distributed by the liquid distributor 23, the deionized water flows downward, and the mixed tail gas flows upward, so that it can contact and react with the deionized water in the packing layer 22. The mixed tail gas reacts with the deionized water in the water... After being dissolved and absorbed by deionized water in the hydration reaction tower 2, a phosphoric acid solution is formed. After gas-liquid contact reaction, the mixed tail gas is treated by gas-liquid separation by the wire mesh demister 24 and discharged through the exhaust pipe 25. The formed phosphoric acid solution falls to the bottom of the hydration reaction tower 2 and then enters the buffer tank 5 through the drain pipe 4. At this time, the circulation pump is turned on, and the phosphoric acid solution in the buffer tank 5 flows into the outlet pipe 6. At this time, the concentration detector in the outlet pipe 6 will detect the concentration of the phosphoric acid solution in a timely manner. The standard concentration of normal thermal phosphoric acid is 85%. If the phosphoric acid concentration in the outlet pipe 6 is lower than the standard value for phosphoric acid production, the circulation control valve is opened and the acid discharge valve is closed. The phosphoric acid solution then enters the first cooler 10 through the circulation pipe 9. After being cooled by the first cooler 10, the temperature of the phosphoric acid solution is cooled to 100-150℃, and then the phosphoric acid solution is returned to the hydration reaction tower 2 for circulation and absorption. This ensures that the reaction temperature in the hydration reaction tower 2 is stable, thereby increasing the absorption concentration of the phosphoric acid solution. If the phosphoric acid concentration in the outlet pipe 6 reaches the standard value for phosphoric acid production... At this time, the circulation control valve is closed and the acid discharge valve is opened. The phosphoric acid solution enters the second cooler 12 through the acid discharge pipe 11. After being cooled by the second cooler 12, the phosphoric acid solution is sent to the phosphoric acid storage tank 13. Before the phosphoric acid solution enters the phosphoric acid storage tank 13, a corresponding separation filter can be installed on the acid discharge pipe 11 to separate the phosphoric acid solution and further improve the quality of phosphoric acid. At the same time, a PLC controller can be used to automatically control the water supply valve, circulation control, circulation pump and acid discharge valve to realize the automated production of the system.
[0010] Furthermore, to improve the absorption effect of deionized water on the mixed exhaust gas, the air inlet distributor 21 includes an air inlet main pipe 211 and distribution branch pipes 212. The air inlet main pipe 211 is horizontally installed through the lower part of the hydration reaction tower 2. The other end of the air inlet main pipe 211 extends to the outside of the hydration reaction tower 2 and is connected to the gas collection pipe 1. The other end of the air inlet main pipe 211 extends to the outside of the hydration reaction tower 2 and is sealed by a blind flange 213. Multiple distribution holes are installed at equal intervals along the axial direction on the top of the air inlet main pipe 211 located inside the hydration reaction tower 2. The distribution branch pipes 212 are vertically installed on the distribution holes. A distribution cone cap 214 is installed on the top of the distribution branch pipes 212 through a connecting rod. The mixed exhaust gas enters the air inlet main pipe 211 through the gas collection pipe 1, and is then distributed to each distribution branch pipe 212 before entering the hydration reaction tower 2. Due to the distribution cone cap 214, the distribution cone cap 214 can effectively absorb the deionized water. The water is diffused to prevent the deionized water from flowing back into the intake manifold 211 during contact with the mixed exhaust gas. This allows the mixed exhaust gas and deionized water to contact evenly, improving the absorption effect of the deionized water on the mixed exhaust gas. Preferably, a bypass pipe 215 is installed at the bottom of the intake manifold 211 located near the blind flange 213. The bypass pipe 215 is connected to the drain pipe 4. The middle of the bypass pipe 215 is provided with 2 to 3 sets of U-shaped bends connected end to end. A bypass valve is provided on the bypass pipe 215. During the contact reaction between the mixed exhaust gas and the deionized water, some deionized water droplets may flow back into the intake manifold 211. At this time, the bypass valve can be opened to discharge the liquid in the intake manifold 211 into the buffer tank 5 through the bypass pipe 215. The U-shaped bends on the bypass pipe 215 mainly serve as gas-liquid separation to prevent the mixed exhaust gas from entering the buffer tank 5 and causing unstable gas pressure in the buffer tank 5.
[0011] Furthermore, the liquid distributor 23 includes a main inlet pipe 231, an upper distribution pipe 232, a lower distribution pipe 233, an upper spray head 234, and a lower spray head 235. The upper and lower distribution pipes 232 and 233 are sealed at both ends. The upper and lower distribution pipes 232 and 233 are installed vertically and alternately inside the hydration reaction tower 2, and are connected by a straight pipe 236. There are 3 to 4 upper spray heads 234, which are evenly distributed inside the hydration reaction tower 2 below the upper distribution pipes 232 via supports. The upper spray heads 234 are connected to the upper distribution pipes 232 via an upper connecting pipe 237. The lower spray heads 235 are installed inside the hydration reaction tower 2 below the lower distribution pipes 233 via supports, and are arranged vertically and alternately with the upper spray heads 234. The structure includes a lower spray head 235 connected to a lower liquid distribution pipe 233 via a lower connecting pipe 238. One end of the liquid inlet main pipe 231 is connected to the upper liquid distribution pipe 232, and the other end is connected to the water supply pipe 3. Preferably, both the upper spray head 234 and the lower spray head 235 are circular spray heads. In use, deionized water entering from the water supply pipe 3 enters the upper liquid distribution pipe 232 through the liquid inlet main pipe 231, and then enters the lower liquid distribution pipe 233 through the straight pipe 236. The deionized water entering the upper liquid distribution pipe 232 enters each upper spray head 234 through the upper connecting pipe 237, and the deionized water entering the lower liquid distribution pipe 233 enters the lower spray head 235 through the lower connecting pipe 238. The upper spray head 234 and the lower spray head 235 simultaneously spray deionized water downwards. After the deionized water forms a water curtain, it can adsorb and treat the high-temperature waste gas.
[0012] Furthermore, a level gauge 51 is installed on the top of the buffer tank 5. The level gauge 51 facilitates the detection of the phosphoric acid solution level in the buffer tank 5. When the liquid level in the buffer tank 5 reaches a high level, the water supply valve can be closed, the water supply pipe 3 can stop supplying deionized water, and then the circulation control valve can be opened to directly use the phosphoric acid solution in the buffer tank 5 for circulation adsorption treatment. When the liquid level in the buffer tank 5 is lower than the minimum liquid level, the water supply valve can be opened and water can be supplied through the water supply pipe 3.
[0013] Furthermore, a thermometer 52 is installed on the side wall of the buffer tank 5. The thermometer 52 facilitates the detection of the temperature of the phosphoric acid solution inside the buffer tank 5. If the temperature inside the buffer tank 5 is too high, corresponding cooling measures can be implemented inside the buffer tank 5, such as installing a spiral coil 53 inside the buffer tank 5. A medium inlet 54 is installed at the bottom of the buffer tank 5, and a medium outlet 55 is installed at the top of the buffer tank 5. The bottom inlet of the spiral coil 53 is connected to the medium inlet 54, and the top outlet of the spiral coil 53 is connected to the medium outlet 55. When the temperature inside the buffer tank 5 is too high, a cooling medium, such as cooling water or cold air, can be supplied to the spiral coil 53 through the medium inlet 54. As the cooling medium flows upward inside the spiral coil 53, it can cool the phosphoric acid solution. After cooling the phosphoric acid solution, the cooling medium is discharged from the medium outlet 55.
Claims
1. A system for the co-production of phosphorus pentoxide and thermal phosphoric acid, comprising a gas collection pipe (1) and a hydration reaction tower (2), characterized in that: The hydration reaction tower (2) is equipped with an air inlet distributor (21), a packing layer (22), a liquid distributor (23), and a wire mesh demister (24) arranged sequentially from bottom to top. The gas collection pipe (1) is connected to the air inlet distributor (21), and the liquid distributor (23) is connected to the water supply pipe (3). A water supply valve is installed on the water supply pipe (3). An exhaust pipe (25) is provided at the top of the hydration reaction tower (2). A buffer tank (5) is connected to the bottom of the hydration reaction tower (2) through a drain pipe (4). The bottom of the buffer tank (5) is equipped with... A liquid outlet pipe (6) is provided, on which a circulation pump and a concentration detector (7) are installed in sequence. A three-way connector (8) is installed at the end of the liquid outlet pipe (6). A circulation pipe (9) connected to a water supply pipe (3) is installed at one outlet of the three-way connector (8). A circulation control valve and a first cooler (10) are installed in sequence on the circulation pipe (9). An acid discharge pipe (11) is connected to the other outlet of the three-way connector (8). An acid discharge valve, a second cooler (12) and a phosphoric acid storage tank (13) are installed in sequence on the acid discharge pipe (11).
2. The co-production system of phosphorus pentoxide and thermal phosphoric acid according to claim 1, characterized in that: The air inlet distributor (21) includes an air inlet main pipe (211) and a distribution branch pipe (212). The air inlet main pipe (211) is installed horizontally through the lower part of the hydration reaction tower (2). The other end of the air inlet main pipe (211) extends to the outside of the hydration reaction tower (2) and is connected to the gas collection pipe (1). The other end of the air inlet main pipe (211) extends to the outside of the hydration reaction tower (2) and is sealed by a blind flange (213). Multiple distribution holes are installed at equal intervals along the axial direction on the top of the air inlet main pipe (211) located inside the hydration reaction tower (2). The distribution branch pipe (212) is installed vertically on the distribution holes. A distribution cone cap (214) is installed on the top of the distribution branch pipe (212) through a connecting rod.
3. The co-production system of phosphorus pentoxide and thermal phosphoric acid according to claim 2, characterized in that: A bypass pipe (215) is installed at the bottom of the main intake pipe (211) located near the blind flange (213). The bypass pipe (215) is connected to the drain pipe (4). Two to three sets of U-shaped bends connected end to end are provided in the middle of the bypass pipe (215). A bypass valve is provided on the bypass pipe (215).
4. The co-production system of phosphorus pentoxide and thermal phosphoric acid according to claim 1, characterized in that: The liquid distributor (23) includes an inlet main pipe (231), an upper distribution pipe (232), a lower distribution pipe (233), an upper spray head (234), and a lower spray head (235). The upper distribution pipe (232) and the lower distribution pipe (233) are sealed at both ends. The upper distribution pipe (232) and the lower distribution pipe (233) are installed vertically and horizontally inside the hydration reaction tower (2). The upper distribution pipe (232) and the lower distribution pipe (233) are connected by a straight pipe (236). There are 3 to 4 upper spray heads (234). The upper spray heads (234) are evenly distributed on the upper distribution pipe (235) by a bracket. 32) Inside the hydration reaction tower (2) below, the upper spray head (234) is connected to the upper liquid distribution pipe (232) through the upper connecting pipe (237). The lower spray head (235) is installed in the hydration reaction tower (2) below the lower liquid distribution pipe (233) by a bracket. The lower spray head (235) and the upper spray head (234) are arranged in an alternating vertical structure. The lower spray head (235) is connected to the lower liquid distribution pipe (233) through the lower connecting pipe (238). One end of the liquid inlet main pipe (231) is connected to the upper liquid distribution pipe (232), and the other end is connected to the water supply pipe (3).
5. The co-production system of phosphorus pentoxide and thermal phosphoric acid according to claim 4, characterized in that: Both the upper spray head (234) and the lower spray head (235) are circular spray heads.
6. The co-production system of phosphorus pentoxide and thermal phosphoric acid according to claim 1, characterized in that: A level gauge (51) is installed on the top of the buffer tank (5).
7. The co-production system of phosphorus pentoxide and thermal phosphoric acid according to claim 1, characterized in that: A thermometer (52) is installed on the side wall of the buffer tank (5).
8. The co-production system of phosphorus pentoxide and thermal phosphoric acid according to claim 1, characterized in that: The buffer tank (5) is equipped with a spiral coil (53) inside. The bottom of the buffer tank (5) is equipped with a medium inlet (54) and the top of the buffer tank (5) is equipped with a medium outlet (55). The bottom inlet of the spiral coil (53) is connected to the medium inlet (54), and the top outlet of the spiral coil (53) is connected to the medium outlet (55).