A phosphorus oxychloride recovery device

Abstract

The utility model discloses a kind of phosphorus oxychloride recovery device, including primary condensing mechanism, buffer mechanism, secondary condensing mechanism and tail gas absorption mechanism connected together in sequence by pipeline, the bottom of primary condensing mechanism, buffer mechanism, secondary condensing mechanism is connected with recovery mechanism by pipeline, the primary condensing mechanism includes first casing, first condensing pipe is installed in the first casing.The utility model is by using the step-by-step condensing process of primary condensation and secondary deep condensation combination, gas state phosphorus oxychloride in reaction tail gas can be condensed and recovered as liquid recovery efficiently, substantially improve the recovery utilization rate of raw material;The device significantly reduces production cost and subsequent tail gas treatment lye consumption and three wastes emissions, while its whole process corrosion-resistant design and the setting of buffer unit, ensure the safety, stability and reliability of system operation, realize the dual purpose of resource recovery and environmental protection emission reduction.

Description

Technical Field

[0001] This utility model belongs to the field of phosphorus oxychloride recovery technology, specifically relating to a phosphorus oxychloride recovery device. Background Technology

[0002] Phosphorus oxychloride is an important chemical raw material and reagent, widely used in the production of pesticides, pharmaceuticals, dyes, and battery electrolytes. In many chlorination or phosphorylation reactions, phosphorus oxychloride is both a reactant and a byproduct, escaping along with gases such as hydrogen chloride.

[0003] Currently, the conventional methods for treating phosphorus oxychloride-containing waste gas are absorption with water or alkaline solutions. Water absorption produces phosphoric acid and hydrochloric acid, which, while treating the waste gas, wastes phosphorus oxychloride resources and the resulting acidic waste is costly and difficult to treat. Alkaline absorption directly produces phosphates and chlorides, similarly failing to recover valuable POCl3 and consuming large amounts of alkaline solution, resulting in high operating costs.

[0004] Therefore, there is an urgent need for a specialized device that can efficiently and safely recover phosphorus oxychloride from reaction tail gas, realize resource recycling, reduce production costs, and reduce emissions of waste gas, wastewater, and solid waste.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0006] The purpose of this utility model is to provide a phosphorus oxychloride recovery device that has a reasonable structure, high recovery efficiency, and safe and reliable operation.

[0007] To achieve the above objectives, the technical solution provided by a specific embodiment of this utility model is as follows:

[0008] A phosphorus oxychloride recovery device includes a primary condensation mechanism, a buffer mechanism, a secondary condensation mechanism, and a tail gas absorption mechanism connected sequentially by pipelines. The bottoms of the primary condensation mechanism, buffer mechanism, and secondary condensation mechanism are connected to a recovery mechanism via pipelines. The primary condensation mechanism includes a first housing with a first condenser tube installed inside, using circulating cooling water as the cooling medium. The buffer mechanism includes a second housing. The secondary condensation mechanism includes a third housing with a second condenser tube installed inside, using chilled brine or ethylene glycol aqueous solution as the cooling medium. The tail gas absorption mechanism includes a fourth housing containing an absorbent liquid. The recovery mechanism includes a recovery tank.

[0009] In one or more embodiments of the present invention, the liquid inlet and liquid outlet of the first condenser tube are integrally formed with a first liquid inlet and a first liquid outlet, respectively. The first liquid inlet is disposed through the bottom of the first housing, and the first liquid outlet is disposed through the top of the first housing.

[0010] In one or more embodiments of this utility model, a first guide plate is fixedly connected to the inner sidewall of the first housing, and the first guide plate is configured as a spiral.

[0011] In one or more embodiments of this utility model, an air inlet pipe is installed on the side wall of the first housing near the bottom, a first drain pipe is installed on the bottom of the first housing, and the lower end of the first drain pipe is installed on the recovery tank.

[0012] In one or more embodiments of this utility model, a first gas supply pipe is installed between the top wall panel of the first housing and the top wall panel of the second housing, a second drain pipe is installed at the bottom of the second housing, and the lower end of the second drain pipe is installed on the recovery tank.

[0013] In one or more embodiments of the present invention, the liquid inlet and liquid outlet of the second condenser tube are integrally formed with a second liquid inlet and a second liquid outlet, respectively. The second liquid inlet is disposed through the bottom of the third housing, and the second liquid outlet is disposed through the top of the third housing.

[0014] In one or more embodiments of this utility model, a second guide plate is fixedly connected to the inner sidewall of the third housing, and the second guide plate is configured as a spiral.

[0015] In one or more embodiments of this utility model, a second gas supply pipe is installed between the bottom sidewall of the second housing and the bottom sidewall of the third housing, and a third drain pipe is installed at the bottom of the third housing, with the lower end of the third drain pipe installed on the recovery tank.

[0016] In one or more embodiments of this utility model, a third gas supply pipe is installed between the top wall panel of the third housing and the bottom side wall of the fourth housing, an exhaust pipe is installed on the top wall panel of the fourth housing, and a waste liquid discharge pipe is installed on the bottom wall panel of the fourth housing.

[0017] In one or more embodiments of this utility model, flow equalization boxes are installed on the inner sidewalls of the first housing and the third housing located at the air inlet. Multiple flow equalization holes are provided in a ring on the wall plate of the flow equalization box away from the inlet, and the multiple flow equalization holes are inclined in a way that diffuses outward.

[0018] Compared with existing technologies, this invention employs a tiered condensation process combining primary and secondary deep condensation, which efficiently and fully condenses and recovers gaseous phosphorus oxychloride from the reaction tail gas into liquid form, significantly improving the recovery rate of raw materials. This device significantly reduces production costs and the consumption of alkali and emissions of waste gas in subsequent tail gas treatment. At the same time, its corrosion-resistant design throughout the process and the inclusion of buffer units ensure the safe, stable, and reliable operation of the system, achieving the dual goals of resource recovery and environmental emission reduction. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a front view of a phosphorus oxychloride recovery device according to an embodiment of the present invention;

[0021] Figure 2 This is a perspective view of a phosphorus oxychloride recovery device according to an embodiment of the present invention;

[0022] Figure 3 This is a cross-sectional view of a phosphorus oxychloride recovery device according to an embodiment of the present invention;

[0023] Figure 4 This is a cross-sectional view of a phosphorus oxychloride recovery device according to one embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the condenser tube in this utility model;

[0025] Figure 6 This is a schematic diagram of the flow equalization box in this utility model.

[0026] Explanation of key figure labels:

[0027] 1-First-stage condensation mechanism, 11-First shell, 12-First condenser tube, 13-First liquid inlet, 14-First liquid outlet, 15-First guide plate, 16-Air inlet pipe, 17-First drain pipe, 18-Flow equalization box, 19-Flow equalization hole, 2-Buffer mechanism, 21-Second shell, 22-Second drain pipe, 23-First gas supply pipe, 3-Second-stage condensation mechanism, 31-Third shell, 32-Second condenser tube, 33-Second liquid inlet, 34-Second liquid outlet, 35-Second guide plate, 36-Second gas supply pipe, 37-Third drain pipe, 4-Tail gas absorption mechanism, 41-Fourth shell, 42-Third gas supply pipe, 43-Exhaust pipe, 44-Waste liquid discharge pipe, 5-Recovery mechanism, 51-Recovery tank. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0029] like Figures 1-4 As shown, a phosphorus oxychloride recovery device in one embodiment of this utility model includes a primary condensation mechanism 1, a buffer mechanism 2, a secondary condensation mechanism 3, and a tail gas absorption mechanism 4 connected in sequence by pipes. The bottom of the primary condensation mechanism 1, the buffer mechanism 2, and the secondary condensation mechanism 3 are connected to a recovery mechanism 5 by pipes. The primary condensation mechanism 1 includes a first housing 11, in which a first condenser tube 12 is installed. Circulating cooling water is used as the cooling medium in the first condenser tube 12. The buffer mechanism 2 includes a second housing 21. The secondary condensation mechanism 3 includes a third housing 31, in which a second condenser tube 32 is installed. The second condenser tube 32 uses chilled brine or ethylene glycol aqueous solution as the cooling medium. The tail gas absorption mechanism 4 includes a fourth housing 41, in which an absorption liquid is provided. The recovery mechanism 5 includes a recovery tank 51.

[0030] When the phosphorus oxychloride recovery device is in use, the high-temperature exhaust gas containing phosphorus oxychloride enters the primary condensation mechanism 1. As the exhaust gas flows in the first housing 11, it comes into contact with the first condenser tube 12. The cooling water in the first condenser tube 12 absorbs the heat of the exhaust gas, cooling the high-temperature exhaust gas to near room temperature, causing most of the gaseous phosphorus oxychloride to condense into liquid. The phosphorus oxychloride condensed into liquid in the first housing 11 flows to the recovery tank 51 for storage. After preliminary condensation in the primary condensation mechanism 1, the exhaust gas enters the buffer mechanism 2, where gas-liquid separation occurs in the second housing 21. The small amount of liquid droplets carried by the exhaust gas are separated here and flow to the recovery tank 51 for storage. The buffer mechanism 2 plays a role in stabilizing the airflow and balancing the system pressure. Subsequently, the gas in the second housing 21 enters the secondary condensation mechanism 3. As the exhaust gas flows through the third housing 31, the second condenser 32 uses chilled brine as a cooling medium to deeply freeze the exhaust gas. At this low temperature, the residual trace amounts of phosphorus oxychloride vapor in the exhaust gas are completely condensed and liquefied. The condensate also flows to the recovery tank 51 for storage. Thus, phosphorus oxychloride in the exhaust gas has been almost completely recovered. Finally, the non-condensable gas containing no phosphorus oxychloride or very low concentrations, mainly HCl gas, enters the exhaust gas absorption mechanism 4. The exhaust gas contacts the absorption liquid in the fourth housing 41, generating a harmless sodium chloride solution, which is collected in the fourth housing 41 and periodically discharged for treatment. The purified, compliant gas is discharged from the top of the fourth housing 41.

[0031] like Figure 2 and Figure 5 As shown, the first condenser tube 12 has an integrally formed first inlet 13 and first outlet 14. The first inlet 13 is disposed through the bottom of the first housing 11, and the first outlet 14 is disposed through the top of the first housing 11. This allows cooling water to enter the bottom of the first condenser tube 12 through the first inlet 13, flow upwards from the bottom within the first condenser tube 12, and then exit through the first outlet 14 at the top.

[0032] like Figure 3 and Figure 4 As shown, a first guide plate 15 is fixedly connected to the inner wall of the first housing 11, and the first guide plate 15 is spiral-shaped. When the exhaust gas flows inside the first housing 11, the effect of the first guide plate 15 on the exhaust gas prolongs the flow time and the uniformity of its distribution within the first housing 11, thereby increasing the contact time and contact area between the exhaust gas and the first condenser 12, and improving the cooling effect of the first condenser 12 on the exhaust gas.

[0033] like Figures 1-4As shown, an air inlet pipe 16 is installed on the side wall of the first housing 11 near the bottom. High-temperature exhaust gas containing phosphorus oxychloride is transported to the bottom of the first housing 11 through the air inlet pipe 16, so that the exhaust gas flows upward from the bottom of the first housing 11, improving the contact effect between the exhaust gas and the first condenser pipe 12. A first drain pipe 17 is installed at the bottom of the first housing 11, and the lower end of the first drain pipe 17 is installed on the recovery tank 51. Phosphorus oxychloride condensed inside the first housing 11 enters the recovery tank 51 through the first drain pipe 17.

[0034] like Figures 1-4 As shown, a first gas supply pipe 23 is installed between the top wall panel of the first housing 11 and the top wall panel of the second housing 21. The treated exhaust gas in the first housing 11 enters the second housing 21 through the first gas supply pipe 23. A second drain pipe 22 is installed at the bottom of the second housing 21, and the lower end of the second drain pipe 22 is installed on the recovery tank 51, so that the phosphorus oxychloride condensed in the second housing 21 enters the recovery tank 51 through the second drain pipe 22.

[0035] like Figure 2 As shown, the second condenser tube 32 has an integrally formed second inlet 33 and a second outlet 34. The second inlet 33 is disposed through the bottom of the third housing 31, and the second outlet 34 is disposed through the top of the third housing 31. This allows the chilled brine or ethylene glycol aqueous solution to enter the bottom of the second condenser tube 32 through the second inlet 33, flow upward from the bottom within the second condenser tube 32, and then exit through the second outlet 34 at the top.

[0036] like Figure 3 and Figure 4 As shown, a second guide plate 35 is fixedly connected to the inner wall of the third housing 31. The second guide plate 35 is spiral-shaped. When the exhaust gas flows inside the third housing 31, the effect of the second guide plate 35 on the exhaust gas prolongs the flow time and distribution uniformity of the exhaust gas inside the third housing 31, thereby increasing the contact time and contact area between the exhaust gas and the second condenser 32, and improving the cooling effect of the second condenser 32 on the exhaust gas.

[0037] like Figures 1-4 As shown, a second gas supply pipe 36 is installed between the bottom sidewall of the second shell 21 and the bottom sidewall of the third shell 31. Gas discharged from the bottom of the second shell 21 is transported to the bottom of the third shell 31 through the second gas supply pipe 36, allowing the exhaust gas in the third shell 31 to flow upwards from the bottom. A third drain pipe 37 is installed at the bottom of the third shell 31, and its lower end is installed on the recovery tank 51. Phosphorus oxychloride condensed inside the third shell 31 enters the recovery tank 51 through the third drain pipe 37.

[0038] like Figures 1-4 As shown, a third gas supply pipe 42 is installed between the top wall of the third housing 31 and the bottom side wall of the fourth housing 41. The exhaust gas treated by the third housing 31 enters the fourth housing 41 through the third gas supply pipe 42 and comes into contact with the absorbent liquid. Simultaneously, the third gas supply pipe 42 delivers the exhaust gas into the bottom of the fourth housing 41 so that the exhaust gas comes into contact with the absorbent liquid inside the fourth housing 41, allowing the absorbent liquid to treat the exhaust gas. To prevent backflow of the absorbent liquid into the fourth housing 41 due to a stoppage in the exhaust gas flow, a one-way valve can be installed on the pipe at the highest point of the third gas supply pipe 42. An exhaust pipe 43 is installed on the top wall of the fourth housing 41, through which the exhaust gas is discharged after treatment by the absorbent liquid. A waste liquid discharge pipe 44 is installed on the bottom wall of the fourth housing 41, through which the product of the treated exhaust gas is periodically discharged by the absorbent liquid.

[0039] like Figure 3 and Figure 6 As shown, flow equalization boxes 18 are installed on the inner walls of the first housing 11 and the third housing 31 at the air inlet. Multiple flow equalization holes 19 are arranged in a ring on the wall plate of the flow equalization box 18 away from the inlet, and these holes are inclined outwards in a diffusing manner. Under the action of the flow equalization boxes 18, the exhaust gas entering the first housing 11 and the third housing 31 is evenly distributed, ensuring that the exhaust gas is uniformly distributed within the first housing 11 and the third housing 31 after being discharged through the multiple flow equalization holes 19, thus improving the condensation effect of the exhaust gas.

[0040] It should be noted that the device provided by this technical solution adopts a corrosion-resistant design throughout the entire process, so that it will not be corroded by phosphorus oxychloride while recovering phosphorus oxychloride.

[0041] In use, the high-temperature exhaust gas containing phosphorus oxychloride is transported to the first housing 11 through the inlet pipe 16. As the exhaust gas flows in the first housing 11, it comes into contact with the first condenser pipe 12. The cooling water in the first condenser pipe 12 absorbs the heat of the exhaust gas and cools it to near room temperature, causing most of the gaseous phosphorus oxychloride to condense into liquid. The phosphorus oxychloride that has condensed into liquid in the first housing 11 flows to the recovery tank 51 for storage. After preliminary condensation in the first housing 11, the exhaust gas enters the second housing 21 through the first gas delivery pipe 23. In the second housing 21, the exhaust gas undergoes gas-liquid separation, and the small amount of liquid droplets carried by the exhaust gas are separated and flow to the recovery tank 51 for storage. The second housing 21 plays a role in stabilizing the airflow and balancing the system pressure. Subsequently, the gas in the second shell 21 enters the third shell 31 through the second gas inlet pipe 36. As the exhaust gas flows within the third shell 31, the second condenser pipe 32 uses chilled brine as a cooling medium to deeply freeze the exhaust gas. At this low temperature, the residual trace amounts of phosphorus oxychloride vapor in the exhaust gas are completely condensed and liquefied. The condensate also flows to the recovery tank 51 for storage. Thus, phosphorus oxychloride in the exhaust gas has been almost completely recovered. Finally, the non-condensable gas, which contains no phosphorus oxychloride or has a very low content and is mainly HCl gas, enters the fourth shell 41. The exhaust gas contacts the absorbent liquid in the fourth shell 41, generating a harmless sodium chloride solution, which is collected in the fourth shell 41 and periodically discharged for treatment. The purified, compliant gas is discharged through the exhaust pipe 43.

[0042] 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.

[0043] 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. A phosphorus oxychloride recovery device, characterized in that, It includes a primary condensation mechanism, a buffer mechanism, a secondary condensation mechanism, and a tail gas absorption mechanism connected sequentially by pipes. The bottoms of the primary condensation mechanism, the buffer mechanism, and the secondary condensation mechanism are connected to a recovery mechanism via pipes. The primary condensation mechanism includes a first housing, in which a first condenser tube is installed, and circulating cooling water is used as the cooling medium in the first condenser tube. The buffer mechanism includes a second housing; The secondary condensation mechanism includes a third housing, and a second condenser tube is installed inside the third housing. The second condenser tube uses a chilled brine or an ethylene glycol aqueous solution as the cooling medium. The exhaust gas absorption mechanism includes a fourth housing, and an absorption liquid is disposed inside the fourth housing; The recycling facility includes recycling tanks.

2. The phosphorus oxychloride recovery device according to claim 1, characterized in that, The first condenser tube has an integrally formed first liquid inlet and first liquid outlet. The first liquid inlet is disposed through the bottom of the first housing, and the first liquid outlet is disposed through the top of the first housing.

3. The phosphorus oxychloride recovery device according to claim 2, characterized in that, A first guide plate is fixedly connected to the inner wall of the first housing, and the first guide plate is configured as a spiral.

4. The phosphorus oxychloride recovery device according to claim 3, characterized in that, An air inlet pipe is installed on the side wall of the first housing near the bottom, and a first drain pipe is installed at the bottom of the first housing. The lower end of the first drain pipe is installed on the recovery tank.

5. The phosphorus oxychloride recovery device according to claim 4, characterized in that, A first gas supply pipe is installed between the top wall panel of the first shell and the top wall panel of the second shell, and a second drain pipe is installed at the bottom of the second shell, with the lower end of the second drain pipe installed on the recovery tank.

6. The phosphorus oxychloride recovery device according to claim 5, characterized in that, The second condenser tube has an integrally formed second liquid inlet and a second liquid outlet. The second liquid inlet is disposed through the bottom of the third housing, and the second liquid outlet is disposed through the top of the third housing.

7. The phosphorus oxychloride recovery device according to claim 6, characterized in that, A second guide plate is fixedly connected to the inner wall of the third housing, and the second guide plate is configured as a spiral.

8. The phosphorus oxychloride recovery device according to claim 7, characterized in that, A second gas supply pipe is installed between the bottom sidewall of the second shell and the bottom sidewall of the third shell, and a third drain pipe is installed at the bottom of the third shell, with the lower end of the third drain pipe installed on the recovery tank.

9. A phosphorus oxychloride recovery device according to claim 8, characterized in that, A third gas supply pipe is installed between the top wall panel of the third housing and the bottom side wall of the fourth housing. An exhaust pipe is installed on the top wall panel of the fourth housing, and a waste liquid discharge pipe is installed on the bottom wall panel of the fourth housing.

10. A phosphorus oxychloride recovery device according to claim 9, characterized in that, Both the first and third housings have flow equalization boxes installed on their inner sidewalls above the air inlet. The flow equalization boxes have multiple flow equalization holes arranged in a ring on the wall panel away from the inlet, and the multiple flow equalization holes are inclined in a way that diffuses outward.

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