An integrated graphite reboiler for refining phosphoric acid

Abstract

This utility model discloses an integrated graphite reboiler for refining phosphoric acid. The reboiler includes a tower body with two symmetrically arranged extension holes (I and II) on both sides of its lower end. Graphite tube sheets (I and II) are respectively installed within extension holes I and II, and several graphite heat exchange tubes connect them. A graphite end cap (I) is located outside extension hole I, and a high-temperature steam inlet is provided on the end cap. A graphite end cap (II) is located outside extension hole II, and a low-temperature steam outlet is provided on the end cap. This utility model's equipment features a simple structure, long service life, low assembly difficulty, low equipment damage during use, low maintenance frequency, low leakage risk, and low heat loss.

Description

Technical Field

[0001] This utility model relates to a phosphoric acid refining equipment, and more particularly to an integrated graphite reboiler tower for refining phosphoric acid. Background Technology

[0002] In the production system of refined phosphoric acid, the graphite distillation column is one of the indispensable core pieces of equipment, typically used in defluorination, washing, and other operational units. Traditional graphite distillation columns for refined phosphoric acid usually require a bottom heating system to heat and evaporate the phosphoric acid. This system generally consists of a circulation pipeline, an axial flow pump, and a graphite reboiler. The process typically involves the phosphoric acid solution in the column bottom flowing out through the circulation pipeline connected to the bottom, then entering the graphite reboiler. There, it exchanges heat with the high-temperature medium and is heated. Under the action of the axial flow pump, it continues to be fed into the distillation column for flash evaporation, and the water vapor is discharged from the column bottom.

[0003] However, traditional graphite tower bottom heating systems have many problems in production practice:

[0004] 1. It requires the cooperation of a reboiler, a reboiler, and a circulation system, resulting in a complex system, bulky equipment, high manufacturing costs, short service life, and difficult assembly.

[0005] 2. When the material from the reboiler circulation outlet enters the tower, the gas-liquid separation reaction force is large, increasing the risk of equipment damage.

[0006] 3. The connection of multiple systems leads to an increase in the number of sealing surfaces, a greater risk of leakage, and a higher frequency of maintenance, which brings instability to production.

[0007] 4. Relying on pipelines for circulation will cause heat loss during the circulation process, which further increases the refining cost.

[0008] Therefore, upgrading the phosphoric acid refining system is necessary. Placing the reboiler inside the reboiler can solve the aforementioned problems to some extent. However, the reboiler is a consumable part, while the reboiler is a durable part. Overcoming the maintenance and repair issues of the reboiler is one of the technical challenges that technicians need to overcome. Utility Model Content

[0009] To address the aforementioned technical problems, this invention provides an integrated graphite reboiler for refining phosphoric acid. The equipment of this invention features a simple structure, long service life, low assembly difficulty, low degree of equipment damage during use, low maintenance frequency, low leakage risk, and minimal heat loss.

[0010] A graphite reboiler integrated tower for refining phosphoric acid is provided, comprising a tower body, with an extended hole one and an extended hole two symmetrically provided on both sides of the lower end of the tower body, and a graphite tube sheet one and a graphite tube sheet two respectively provided in the extended hole one and the extended hole two, and a plurality of graphite heat exchange tubes connected between the graphite tube sheet one and the graphite tube sheet two.

[0011] A graphite head is provided on the outer side of the first extension hole, and a high-temperature steam inlet is provided on the first graphite head;

[0012] The outer side of the second extension hole is provided with a second graphite end cap, and the second graphite end cap is provided with a low-temperature steam outlet.

[0013] The tower reboiler in this solution integrates graphite heat exchange tubes into the tower body, forming a single structure. Compared with the traditional multi-system combination structure, the integrated tower reboiler structure of this solution is simpler, easier to assemble, and has lower equipment costs. Furthermore, since there is no backlash from the circulation pipe, the equipment is less damaged during use, has a longer service life, requires less maintenance, and has a lower risk of leakage.

[0014] Preferably, in the aforementioned integrated graphite reboiler for refining phosphoric acid, the epitaxial hole one and the graphite tube sheet one, as well as the epitaxial hole two and the graphite tube sheet two, adopt a floating connection structure.

[0015] More preferably, in the aforementioned integrated graphite reboiler for refining phosphoric acid, the floating connection structure includes a V-groove located on the inner side of the connection surface between the first epitaxial hole and the first graphite head, and on the inner side of the connection surface between the second epitaxial hole and the second graphite head, and an O-ring seal located within the V-groove.

[0016] The graphite tube sheet in this design adopts a floating connection structure, which can ensure the reliability of the sealing connection between the graphite tube sheet and the extension hole during thermal expansion and contraction, further reducing the risk of leakage; and the combination of V-groove and O-ring further improves the reliability of the seal.

[0017] Preferably, in the aforementioned integrated graphite reboiler for refining phosphoric acid, a flange is provided at the end edge of the first extension hole, and a cover plate is provided on the outside of the first graphite head, with the flange and the cover plate being fixed together by bolts.

[0018] Preferably, in the aforementioned integrated graphite reboiler for refining phosphoric acid, a flange is provided at the end edge of the second extension hole, a cover plate is provided on the outside of the second graphite head, and the flange and the cover plate are fixed together by bolts.

[0019] The graphite end cap and the extension hole in this design are fixed with bolts, which makes the structure simple and the graphite heat exchange tube easier to assemble and maintain.

[0020] Preferably, in the aforementioned integrated graphite reboiler for refining phosphoric acid, the column body is mounted on a base support.

[0021] Preferably, in the aforementioned integrated graphite reboiler for refining phosphoric acid, the bottom of the column body is provided with a material outlet, the upper side is provided with a material inlet, and the top is provided with a gas outlet.

[0022] 1. The tower kettle of this utility model integrates graphite heat exchange tubes into the tower body, forming an integral structure with the tower body. Compared with the traditional multi-system combination structure, the integrated tower kettle of this utility model has a simpler structure, lower assembly difficulty, and lower equipment cost. Since there is no backflow force from the circulation pipe, the equipment is less damaged during use, has a longer service life, lower maintenance frequency, and lower leakage risk.

[0023] 2. The graphite tube sheet of this utility model adopts a floating connection structure, which can ensure the reliability of the sealing connection between the graphite tube sheet and the outer hole during thermal expansion and contraction, and further reduce the risk of leakage; while the combination of V-groove and O-ring further improves the reliability of sealing.

[0024] 3. The graphite end cap and the outer hole of this utility model are fixed by bolts, which makes the structure simple and the graphite heat exchange tube easier to assemble and maintain.

[0025] In summary, the tower reactor of this utility model has the advantages of simple structure, long service life, low assembly difficulty, low degree of equipment damage during use, low maintenance frequency, low risk of leakage and low heat loss. Attached Figure Description

[0026] Appendix Figure 1 This is a schematic diagram of the integrated tower reactor of this utility model;

[0027] Appendix Figure 2 For the appendix Figure 1 AA view;

[0028] Appendix Figure 3 For the appendix Figure 2 Enlarged view of area D.

[0029] Explanation of reference numerals in the attached drawings: 1-Tower body, 2-Material outlet, 3-Gas outlet, 4-Extension hole one, 5-Extension hole two, 6-Graphite tube sheet one, 7-Graphite tube sheet two, 8-Graphite heat exchange tube, 9-Graphite head one, 10-High-temperature steam inlet, 11-Graphite head two, 12-Low-temperature steam outlet, 13-Base support, 14-Flange one, 15-Cover plate one, 16-Bolt one, 17-Flange two, 18-Cover plate two, 19-Bolt two, 20-V-groove, 21-O-ring seal, 22-Material inlet. Detailed Implementation

[0030] The present invention will be further described below with reference to the embodiments, but this should not be construed as limiting the present invention.

[0031] Embodiments of this utility model

[0032] An integrated graphite reboiler for refining phosphoric acid, as shown in the attached figure. Figure 1-3 As shown, it includes a tower body 1. The lower end of the tower body 1 is symmetrically provided with an extension hole 4 and an extension hole 5 on both sides. Graphite tube sheet 6 and graphite tube sheet 7 are respectively provided in the extension hole 4 and the extension hole 5. Several graphite heat exchange tubes 8 are connected between the graphite tube sheet 6 and the graphite tube sheet 7.

[0033] A graphite end cap 9 is provided on the outer side of the extension hole 4, and a high-temperature steam inlet 10 is provided on the graphite end cap 9.

[0034] The outer side of the second extension hole 5 is provided with a graphite end cap 11, and the graphite end cap 11 is provided with a low temperature steam outlet 12.

[0035] In this embodiment, the integrated reboiler tower is used by first feeding the phosphoric acid solution to be purified into the tower body 1, submerging the graphite heat exchange tubes 8 at the bottom. Then, high-temperature steam is fed in from the high-temperature steam inlet 10 and flows through the interior of the graphite heat exchange tubes 8. After exchanging heat with the phosphoric acid solution outside the graphite heat exchange tubes 8, the high-temperature steam becomes low-temperature steam and is then discharged from the low-temperature steam outlet 12. Meanwhile, the phosphoric acid solution inside the tower body 1 is heated at high temperature by the graphite heat exchange tubes 8, causing the water and volatile impurities in it to evaporate and be discharged from the tower body 1, thus completing the purification process.

[0036] Further implementation, for example, is attached. Figure 1-3 As shown, the epitaxial hole 4 and the graphite tube sheet 6, as well as the epitaxial hole 5 and the graphite tube sheet 7, adopt a floating connection structure.

[0037] Further implementation, for example, is attached. Figure 1-3 As shown, the floating connection structure includes a V-groove 20 located on the inner side of the connection surface between the extension hole 4 and the graphite head 9, and on the inner side of the connection surface between the extension hole 5 and the graphite head 11, and an O-ring 21 located in the V-groove 20.

[0038] During assembly, the O-ring 21 is first placed within the outer circumferential surface of the graphite head and maintains sliding contact with the outer circumferential surface of the graphite head. Under the squeezing action of the side walls on both sides of the V-groove 20, the O-ring 21 can maintain close contact with the surrounding contact surface in real time to ensure sealing.

[0039] Further implementation, for example, is attached. Figure 1-3As shown, a flange 14 is provided at the end edge of the extension hole 4, and a cover plate 15 is provided on the outside of the graphite head 9. The flange 14 and the cover plate 15 are fixed together by bolts 16.

[0040] Further implementation, for example, is attached. Figure 1-3 As shown, a flange 17 is provided at the end edge of the extension hole 2 5, and a cover plate 2 18 is provided on the outside of the graphite head 2 11. The flange 2 17 and the cover plate 2 18 are fixed together by bolts 2 19.

[0041] During assembly, first loosen the bolts and remove the cover plate and graphite head. Then, insert the graphite head 1 (9), graphite heat exchange tube 8, and graphite head 2 (11), which have been assembled as a whole, into the outer hole on one side. After inserting into the set position, cover the graphite head and cover plate and tighten the bolts. When disassembling, inspecting, or replacing the graphite heat exchange component, simply open the graphite head and remove it, which is very convenient.

[0042] Further implementation, for example, is attached. Figure 1-3 As shown, the tower body 1 is mounted on the base bracket 13. The base bracket 13 is used to fix the tower body at the installation site.

[0043] Further implementation, for example, is attached. Figure 1-3 As shown, the tower body 1 has a material outlet 2 at the bottom, a material inlet 22 on the upper side, and a gas outlet 3 at the top. The refined material is discharged from the material outlet 2 and stored, while new material is fed in through the material inlet 22, and the generated gas is discharged from the gas outlet 3. Example 2

[0044] A method for refining phosphoric acid using an integrated graphite reboiler tower involves feeding the phosphoric acid solution to be refined into the tower body 1, while simultaneously introducing high-temperature steam into the graphite heat exchange tube 8 through the high-temperature steam inlet 10. The phosphoric acid solution is evaporated and concentrated under the heating action of the graphite heat exchange tube 8, thereby completing the refining process directly inside the tower.

[0045] The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be included within the protection scope of the present invention.

Claims

1. A graphite reboiler integrated kettle for refining phosphoric acid, characterized by: It includes a tower body (1), and two symmetrical extension holes (4) and two extension holes (5) are provided on both sides of the lower end of the tower body (1). Graphite tube sheet (6) and graphite tube sheet (7) are respectively provided in the extension holes (4) and the extension holes (5). Several graphite heat exchange tubes (8) are connected between the graphite tube sheet (6) and the graphite tube sheet (7). The outer side of the extension hole (4) is provided with a graphite head (9), and the graphite head (9) is provided with a high-temperature steam inlet (10). The outer side of the second epitaxial hole (5) is provided with a second graphite head (11), and the second graphite head (11) is provided with a low-temperature steam outlet (12).

2. The graphite reboiler integrated kettle for refining phosphoric acid as claimed in claim 1 wherein: The epitaxial hole one (4) and the graphite tube plate one (6) and the epitaxial hole two (5) and the graphite tube plate two (7) adopt a floating connection structure.

3. The graphite reboiler integrated kettle for refining phosphoric acid as claimed in claim 2 wherein: The floating connection structure includes a V-groove (20) located on the inner side of the connection surface between the first extension hole (4) and the first graphite head (9) and the inner side of the connection surface between the second extension hole (5) and the second graphite head (11), and an O-ring (21) located in the V-groove (20).

4. The graphite reboiler integrated kettle for refining phosphoric acid as claimed in claim 1 wherein: A flange (14) is provided at the end edge of the extension hole (4), and a cover plate (15) is provided on the outside of the graphite head (9). The flange (14) and the cover plate (15) are fixed together by bolts (16).

5. The graphite reboiler integrated kettle for refining phosphoric acid as claimed in claim 1 wherein: The second flange (17) is provided at the end edge of the second extension hole (5), and the second cover plate (18) is provided on the outside of the second graphite head (11). The second flange (17) and the second cover plate (18) are fixed together by the second bolt (19).

6. The graphite reboiler integrated kettle for refining phosphoric acid as claimed in claim 1 wherein: The tower body (1) is mounted on the base support (13).

7. The graphite reboiler integrated kettle for refining phosphoric acid as claimed in claim 1 wherein: The tower body (1) has a material outlet (2) at the bottom, a material inlet (22) on the side at the top, and a gas outlet (3) at the top.

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