Continuous phosphorus recovery system

Abstract

The utility model discloses a continuous phosphorus recovery system, which comprises an extraction and separation tower, which comprises a plurality of heat exchange units arranged along the longitudinal direction and connected in sequence; each heat exchange unit comprises a drying cavity used for containing wet materials and a heat supply cavity formed in the outer layer of the drying cavity. The at least one heating furnace is used for supplying heat to the heat supply cavity corresponding to the at least one heat exchange unit; the proportion of the number of the heating furnaces to the number of the heat exchange units is 1 / 4-1 / 2; the at least one exhaust pipe is used for being connected with the at least one heat exchange unit; the nitrogen supply unit comprises a nitrogen tank and gas supply pipes for connecting the nitrogen tank with the drying cavities respectively included in the plurality of heat exchange units of the extraction and separation tower; and the cooling recovery unit comprises a recovery pipeline connected with at least one exhaust pipe, a cooling assembly connected with the recovery pipeline and a recovery tank connected with the cooling assembly. The phosphorus recovery device can improve the recovery efficiency of phosphorus and the safety of the recovery process.

Description

Technical Field

[0001] This utility model relates to the field of phosphorus recovery technology, and in particular to a continuous phosphorus recovery system. Background Technology

[0002] The production of yellow phosphorus using the electric furnace method generates waste such as phosphorus mud and phosphorus slag. Phosphorus mud is one of the main byproducts of yellow phosphorus production and is classified as a hazardous solid waste in the phosphorus chemical industry. The treatment and utilization of phosphorus mud is a very important issue in the production of yellow phosphorus. It not only affects the phosphorus recovery rate and production cost in the yellow phosphorus industrial production, but more seriously, it causes serious environmental pollution problems.

[0003] Existing methods for recovering yellow phosphorus include steam filtration. Steam filtration involves placing phosphorus mud and slag in a container and continuously heating it with steam to dissolve the phosphorus mud and slag. The phosphorus filtered out is then refined into finished yellow phosphorus. However, a certain amount of phosphorus cannot be recovered from the phosphorus mud and slag treated by this method. Moreover, it consumes a lot of steam, has a long production cycle, and causes serious pollution.

[0004] Based on the above, CN216662490U discloses a closed, combined continuous phosphorus recovery system for mud. While this system achieves phosphorus recovery and utilization by combining a mud-phosphorus tank, a mud-phosphorus converter, a condenser, and a phosphorus collection tank, the mud-phosphorus converter method suffers from low recovery efficiency and small single-cycle recovery volume. Furthermore, phosphorus may react with airborne phosphorus to produce phosphorus pentoxide, reducing the recovery rate, and at certain temperatures, it may also spontaneously combust, causing safety accidents. Therefore, the continuous phosphorus recovery system for mud disclosed above also suffers from reduced recovery rates and even safety accidents due to contact with air.

[0005] Therefore, for phosphorus recovery systems, it is necessary to further optimize their overall structure to improve phosphorus recovery efficiency and enhance the safety of the recovery process. Utility Model Content

[0006] The purpose of this invention is to provide a continuous phosphorus recovery system to solve the technical problems of improving phosphorus recovery efficiency and enhancing the safety of the recovery process.

[0007] The continuous phosphorus recovery system of this invention is implemented as follows:

[0008] A continuous phosphorus recovery system includes:

[0009] An extraction and separation tower includes multiple heat exchange units arranged longitudinally and connected in sequence; each heat exchange unit includes a drying chamber for containing wet materials and a heating chamber disposed on the outer layer of the drying chamber.

[0010] At least one heating furnace is used to heat the heating chamber corresponding to at least one heat exchange unit; and the ratio of the number of heating furnaces to the number of heat exchange units is 1 / 4 to 1 / 2.

[0011] At least one exhaust pipe for connecting at least one heat exchange unit;

[0012] A nitrogen supply unit includes a nitrogen tank and a gas supply pipe for connecting the nitrogen tank and the drying chambers of multiple heat exchange units in the extraction and separation tower.

[0013] A cooling recovery unit includes a recovery pipeline connected to at least one exhaust pipe, a cooling assembly connected to the recovery pipeline, and a recovery tank connected to the cooling assembly.

[0014] In an optional embodiment of this invention, the ratio of the number of heating furnaces to the number of heat exchange units is 1 / 3.

[0015] In an optional embodiment of this utility model, the extraction and separation tower includes twelve heat exchange units arranged longitudinally and connected in sequence;

[0016] The twelve heat exchange units correspond to four heating furnaces, and each heating furnace corresponds to three heat exchange units; and

[0017] The twelve heat exchange units correspond to two exhaust pipes, and each exhaust pipe corresponds to six heat exchange units.

[0018] In an optional embodiment of this invention, a feed pipe suitable for the passage of wet materials is also provided between the drying chambers of the plurality of heat exchange units.

[0019] In an optional embodiment of this invention, the drying chamber of the heat exchange unit corresponding to the top of the extraction and separation tower is further equipped with a feed inlet suitable for the entry of wet materials; and

[0020] The drying chamber of the heat exchange unit corresponding to the bottom of the extraction and separation tower is also equipped with a discharge port suitable for the discharge of dried materials.

[0021] In an optional embodiment of this utility model, the lower part of the discharge port is connected to the inlet of a screw feeder; and

[0022] The screw feeder is connected to a water inlet pipe to allow water to flow into the screw feeder.

[0023] In an optional embodiment of this invention, the heating chambers of the plurality of heat exchange units are also connected to a waste heat pipe.

[0024] In an optional embodiment of this invention, the extraction and separation tower further includes a stirring assembly that runs through a drying chamber that penetrates multiple heat exchange units;

[0025] The agitation assembly includes a rotating main shaft and blades mounted on the rotating main shaft and located in the drying chamber of each heat exchange unit for agitating the wet material.

[0026] In an optional embodiment of this invention, the recycling tank is equipped with a drain outlet and a discharge outlet.

[0027] In an optional embodiment of this utility model, a connecting air duct is provided between the drying chambers of the plurality of heat exchange units; the air duct is connected to the air supply pipe.

[0028] By adopting the above technical solution, the present invention has the following beneficial effects: The continuous phosphorus recovery system of the present invention, through the combined use of an extraction and separation tower, at least one heating furnace, at least one exhaust pipe, a nitrogen supply unit and a cooling recovery unit, can not only improve the recovery efficiency of phosphorus in wastes such as phosphorus mud and phosphorus slag, but also improve the safety of the recovery process through the nitrogen supply unit. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the continuous phosphorus recovery system of this utility model;

[0030] Figure 2 This is a schematic diagram of the extraction and separation tower of the continuous phosphorus recovery system of this utility model;

[0031] Figure 3 This is a schematic diagram of the screw feeding device of the continuous phosphorus recovery system of this utility model.

[0032] In the diagram: 1. Nitrogen tank; 2. Waste heat pipe; 3. Feed inlet; 4. Paddle; 5. Heating chamber; 6. Exhaust pipe; 7. Heating furnace; 8. Cooling tower; 9. Recovery tank; 10. Discharge outlet; 11. Rotary spindle; 12. Discharge port; 13. Reducer; 14. Sewage outlet; 15. Extraction and separation tower; 16. Drying chamber; 17. Gas supply pipe; 18. Recovery pipeline; 19. Screw feeder; 20. Water inlet. Detailed Implementation

[0033] To make the contents of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0034] Example 1:

[0035] Please see Figures 1 to 3 As shown, this embodiment provides a continuous phosphorus recovery system, including: an extraction and separation tower 15, at least one heating furnace 7, at least one exhaust pipe 6, a nitrogen supply unit, and a cooling and recovery unit.

[0036] Specifically, the extraction and separation tower 15 includes multiple heat exchange units arranged longitudinally and connected in sequence. Each heat exchange unit includes a drying chamber 16 for containing wet material and a heating chamber 5 located on the outer layer of the drying chamber 16. In one optional embodiment, the extraction and separation tower 15 includes twelve heat exchange units arranged longitudinally and connected in sequence. Based on these heat exchange units, the wet material in the drying chamber 16 is heated by the heating chamber 5, causing the phosphorus in the wet material to vaporize into a gaseous state and be discharged from the exhaust pipe 6.

[0037] Based on the above, it should also be noted that a feed pipe suitable for the passage of wet materials is provided between the drying chambers 16 of the multiple heat exchange units. Furthermore, the drying chamber 16 of the heat exchange unit corresponding to the top of the extraction and separation tower 15 is also equipped with a feed inlet 3 suitable for the entry of wet materials; and the drying chamber 16 of the heat exchange unit corresponding to the bottom of the extraction and separation tower 15 is also equipped with a discharge port 12 suitable for the discharge of phosphorus-free dry materials. In this structure, the feed inlet 3 and discharge port 12 are located at opposite ends of the extraction and separation tower 15, enabling continuous operation of the entire phosphorus recovery system. While dry materials containing no phosphorus or trace amounts of phosphorus are discharged through the discharge port 12, phosphorus-containing wet materials are simultaneously reintroduced into the extraction and separation tower 15 through the feed inlet 3, thereby improving the phosphorus recovery efficiency from batches of phosphorus mud, phosphorus slag, and other waste materials.

[0038] Based on the above, in one optional implementation, the discharge port 12 is connected to the inlet of a screw conveyor 19; and the screw conveyor 19 is connected to a water inlet pipe to allow water to flow into the screw conveyor 19. For this purpose, a water inlet 20 for connecting the water inlet pipe is provided on the side wall of the screw conveyor 19. The screw conveyor 19 can be any mature twin-screw or single-bolt conveyor from the prior art; this embodiment does not impose an absolute limitation on this. Based on this structure, by introducing cooling water into the screw conveyor 19 through the water inlet pipe for the dry material that needs to be discharged after entering the screw conveyor 19, on the one hand, it can cool the dry material that does not contain phosphorus or contains trace amounts of phosphorus in a timely manner, facilitating the collection of the cooled material, thus reducing the temperature resistance requirements of the collection container; on the other hand, it can also prevent the generation of a large amount of dust when the dry material that does not contain phosphorus or contains trace amounts of phosphorus is discharged from the screw conveyor 19. On the other hand, a water seal can be used to ensure a sealed environment inside the screw feeder 19, so that the entire drying process of waste materials such as phosphorus mud and phosphorus slag and the phosphorus recovery process are always in a closed environment that is isolated from air.

[0039] Furthermore, regarding the heating furnace 7, it is used to heat the heating chamber 5 corresponding to the heat exchange units. It should be noted that, to balance the heating requirements and heat exchange efficiency of the drying chambers 16 of different heat exchange units, the ratio of the number of heating furnaces 7 to the number of heat exchange units is 1 / 4 to 1 / 2. For example, the ratio of heating furnace 7 to the number of heat exchange units is 1 / 3. Therefore, four heating furnaces 7 are used for twelve heat exchange units, meaning each heating furnace 7 corresponds to three heat exchange units. This ensures that the heat generated by one heating furnace 7 is sufficient for three heat exchange units while avoiding the increased cost of using too many heating furnaces 7. The waste heat after heat exchange needs to be discharged; therefore, the heating chambers 5 of each heat exchange unit are also connected to a waste heat pipe 2.

[0040] Next is the nitrogen supply unit, which includes a nitrogen tank 1 and gas supply pipes 17 for connecting the nitrogen tank 1 to the drying chambers 16 of the multiple heat exchange units in the extraction and separation tower 15. For this purpose, interconnecting ventilation pipes are provided between the drying chambers 16 of the multiple heat exchange units; these ventilation pipes are connected to the gas supply pipes 17. Here, the nitrogen supply unit completely replaces the oxygen in the drying chambers 16 of the multiple heat exchange units before the continuous phosphorus recovery system operates, preventing the air from reacting with phosphorus to produce phosphorus pentoxide.

[0041] Furthermore, at least one exhaust pipe 6 is used to connect at least one heat exchange unit; twelve heat exchange units correspond to two exhaust pipes 6, and each exhaust pipe 6 corresponds to six heat exchange units.

[0042] Finally, there is a cooling recovery unit, which includes a recovery pipe 18 connected to at least one exhaust pipe 6, a cooling assembly connected to the recovery pipe 18, and a recovery tank 9 connected to the cooling assembly. In an optional embodiment, the cooling assembly includes three cooling towers 8 connected in sequence.

[0043] When two exhaust pipes 6 are installed, each of these two exhaust pipes 6 is connected to the cooling assembly via a recovery pipe 18. Phosphorus in the wet material in the drying chamber 16 is vaporized and discharged from the exhaust pipe 6 into the recovery pipe 18. Since the wet material also contains water vapor, the gas entering the recovery pipe 18 through the exhaust pipe 6 contains not only gaseous phosphorus but also water vapor. After cooling by the cooling assembly, a mixture of solid phosphorus and liquid water is formed. The solid phosphorus and liquid water can be separated by utilizing the difference in their states. The recovery tank 9 is equipped with a drain port 14 and a discharge port 10. The discharge port 10 is used to discharge solid phosphorus, while the drain port 14 is used to discharge liquid water. For the discharge port 10, a suction pipe combined with a pump can be used to suck out the solid phosphorus from the recovery tank 9.

[0044] Of course, it should also be noted that, in order to improve the drying efficiency of the wet material in the drying chamber 16, the extraction and separation tower 15 of this embodiment also includes an agitation assembly that runs through the drying chamber 16 of multiple heat exchange units; the agitation assembly includes a rotating main shaft 11 and impellers 4 disposed on the rotating main shaft 11 and respectively located in the drying chamber 16 of each heat exchange unit for agitating the wet material. For this purpose, a reducer 13 for driving the rotating main shaft 11 is provided at the bottom of the extraction and separation tower 15.

[0045] In summary, regarding the continuous phosphorus recovery system of this embodiment, wet materials such as phosphorus mud and phosphorus slag are sequentially fed into the drying chambers 16 of multiple heat exchange units through the feed inlet 3. Then, nitrogen from the nitrogen tank 1 enters the drying chambers 16 through the exhaust pipe 6 to replace the air in the drying chambers 16. After the air-nitrogen replacement is complete, the heating furnace 7 heats the heating chamber 5 of each heat exchange unit, thereby heating the wet materials in each drying chamber 16. This causes the phosphorus in the wet materials to vaporize into a gaseous state, which, combined with the water vapor formed during heating, is discharged from the exhaust pipe 6 into the recovery pipeline 18. The gaseous phosphorus and water vapor in the recovery pipeline 18, after being cooled by the cooling components, form a mixture of solid phosphorus and liquid water. The solid phosphorus and liquid water can then be separated by utilizing the difference in their states. The recovery tank 9 is equipped with a drain outlet 14 and a discharge outlet 10. The discharge outlet 10 is used to discharge solid phosphorus, while the drain outlet 14 is used to discharge liquid water. In summary, by using an extraction and separation tower 15, at least one heating furnace 7, at least one exhaust pipe 6, a nitrogen supply unit, and a cooling and recovery unit in combination, not only can the recovery efficiency of phosphorus in wastes such as phosphorus mud and phosphorus slag be improved, but the nitrogen supply unit can also improve the safety of the recovery process.

[0046] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above are only specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0047] In the description of this utility model, it should be understood that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0048] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0049] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. 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. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0050] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0051] In this invention, unless otherwise expressly specified and limited, "above or below" the first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

Claims

1. A continuous phosphorus recovery system, characterized in that, include: An extraction and separation tower includes multiple heat exchange units arranged longitudinally and connected in sequence; each heat exchange unit includes a drying chamber for containing wet materials and a heating chamber disposed on the outer layer of the drying chamber. At least one heating furnace is used to heat the heating chamber corresponding to at least one heat exchange unit; and the ratio of the number of heating furnaces to the number of heat exchange units is 1 / 4 to 1 / 2. At least one exhaust pipe for connecting at least one heat exchange unit; A nitrogen supply unit, comprising a nitrogen tank and a supply pipe for connecting the nitrogen tank to multiple drying chambers of an extraction and separation tower; A cooling recovery unit includes a recovery pipeline connected to at least one exhaust pipe, a cooling assembly connected to the recovery pipeline, and a recovery tank connected to the cooling assembly.

2. The continuous phosphorus recovery system according to claim 1, characterized in that, The ratio of the number of heating furnaces to the number of heat exchange units is 1 / 3.

3. The continuous phosphorus recovery system according to claim 2, characterized in that, The extraction and separation tower comprises twelve heat exchange units arranged longitudinally and connected in sequence; The twelve heat exchange units correspond to four heating furnaces, and each heating furnace corresponds to three heat exchange units; and The twelve heat exchange units correspond to two exhaust pipes, and each exhaust pipe corresponds to six heat exchange units.

4. The continuous phosphorus recovery system according to any one of claims 1 to 3, characterized in that, A feed pipe suitable for the passage of wet materials is also provided between the drying chambers of the multiple heat exchange units.

5. The continuous phosphorus recovery system according to claim 4, characterized in that, The drying chamber of the heat exchange unit corresponding to the top of the extraction and separation tower is also equipped with a feed inlet suitable for wet materials to enter; and The drying chamber of the heat exchange unit corresponding to the bottom of the extraction and separation tower is also equipped with a discharge port suitable for the discharge of dried materials.

6. The continuous phosphorus recovery system according to claim 5, characterized in that, The discharge port is connected below to the inlet of a screw feeder; and The screw feeder is connected to a water inlet pipe to allow water to flow into the screw feeder.

7. The continuous phosphorus recovery system according to any one of claims 1 to 3, characterized in that, The heating chambers of the multiple heat exchange units are also connected to a waste heat pipe.

8. The continuous phosphorus recovery system according to claim 1, characterized in that, The extraction and separation tower also includes a stirring assembly that runs through a drying chamber that spans multiple heat exchange units; The agitation assembly includes a rotating main shaft and blades mounted on the rotating main shaft and located in the drying chamber of each heat exchange unit for agitating the wet material.

9. The continuous phosphorus recovery system according to claim 1 or 8, characterized in that, The recycling tank is equipped with a sewage outlet and a material outlet.

10. The continuous phosphorus recovery system according to claim 1, characterized in that, The drying chambers of the multiple heat exchange units are also connected by ventilation pipes; the ventilation pipes are connected to the air supply pipes.

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