Cold side jacket structure and para-xylene crystallizer

Abstract

This utility model discloses a cold-side jacket structure and a paraxylene crystallizer. The cold-side jacket structure includes an annular tube, a delivery tube, an inlet tube, and an outlet tube. Two annular tubes are arranged vertically at intervals. Multiple delivery tubes are arranged between two annular tubes and along the circumference of the annular tubes, with each delivery tube connected to two annular tubes at both ends. The inlet tube is connected to the lower annular tube and has a first porous component inside. The outlet tube is connected to the upper annular tube and has a second porous component inside. The cold-side jacket structure provided by this application solves the problem of uneven distribution of refrigerant fluid during flow within multiple delivery tubes.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, and in particular to a cold-side jacket structure and a paraxylene crystallizer. Background Technology

[0002] Para-xylene (PX) is an organic compound and an important petrochemical product that connects oil refining and chemical processing. It is one of the most important aromatic products and a leading raw material for the polyester industry.

[0003] Currently, the main separation technologies suitable for large-scale PX production are simulated moving bed adsorption separation and freeze crystallization separation. Among them, freeze crystallization separation technology has advantages such as relaxed requirements on raw material purity, high electrification rate, and high product purity, and is increasingly valued.

[0004] The crystallizer is the core equipment of the freeze crystallization separation technology. Currently, the existing paraxylene crystallizers mainly use the refrigerant in the cold side jacket to indirectly transfer heat to remove the heat generated during the PX crystallization process, thereby separating paraxylene crystals from the mixed xylene. Summary of the Invention

[0005] To enrich the variety of cold-side jacket structures and improve the heat transfer efficiency of refrigerant within the cold-side jacket structure, this utility model provides a cold-side jacket structure and a paraxylene crystallizer.

[0006] In a first aspect, the present invention proposes a cold-side jacket structure, comprising: an annular tube, an infusion tube, an inlet tube, and an outlet tube; Two annular tubes are provided, and the two annular tubes are arranged vertically at a distance from each other; Multiple infusion tubes are provided, and the multiple infusion tubes are arranged between two annular tubes and along the circumference of the annular tubes. The two ends of each infusion tube are respectively connected to the two annular tubes. The inlet pipe is connected to the annular pipe located below. The inlet pipe is provided with a first porous component. The first porous component includes a first main body and a first through hole and a second through hole penetrating the first main body. The first through hole is located at the upper part of the first main body, and the second through hole is located at the lower part of the first main body. The diameter of the first through hole is smaller than the diameter of the second through hole. The outlet pipe is connected to the annular pipe located above. The outlet pipe is provided with a second porous component. The second porous component includes a second main body and a third through hole and a fourth through hole penetrating the second main body. The third through hole is located in the upper part of the second main body, and the fourth through hole is located in the lower part of the second main body. The diameter of the third through hole is larger than the diameter of the fourth through hole.

[0007] Optionally, multiple first through holes and multiple second through holes are provided, with multiple first through holes spaced apart on the upper part of the first main body, and multiple second through holes spaced apart on the middle and lower parts of the first main body; Multiple third through holes and multiple fourth through holes are provided. The multiple third through holes are arranged at intervals in the upper and middle parts of the second main body, and the multiple fourth through holes are arranged at intervals in the lower part of the second main body.

[0008] Optionally, the first porous component and the second porous component are arranged in a mirror-symmetric manner about a horizontal reference plane.

[0009] Optionally, two inlet pipes and two outlet pipes are provided. The inlet pipes are respectively provided on the opposite sides of the lower annular pipe, and the outlet pipes are respectively provided on the opposite sides of the upper annular pipe. The two inlet pipes and the two outlet pipes correspond one-to-one in the vertical direction.

[0010] Optionally, the infusion tube is a semi-circular tube, and the arc portion of the semi-circular tube is away from the paraxylene crystallizer.

[0011] Optionally, the sides of multiple infusion tubes are connected sequentially along the circumferential direction of the annular tube.

[0012] Optionally, the diameter of the first through hole is 5 mm, and the diameter of the second through hole is 10 mm.

[0013] Optionally, the diameter of the third through hole is 10 mm, and the diameter of the fourth through hole is 5 mm.

[0014] Optionally, multiple cold-side jacket structures are provided and connected sequentially along the vertical direction.

[0015] Secondly, the present invention provides a paraxylene crystallizer, comprising a crystallizer body and the cold-side jacket structure described in the first aspect, wherein the cold-side jacket structure is sleeved on the outside of the crystallizer body.

[0016] The beneficial effects of the above-mentioned technical solutions provided by the embodiments of this utility model include at least the following: The cold-side jacket structure provided by this utility model includes a first porous component in the inlet pipe and a second porous component in the outlet pipe. The first porous component includes a first main body and a first through hole and a second through hole penetrating the first main body. The first through hole is located at the upper part of the first main body, and the second through hole is located at the lower part of the first main body. The diameter of the first through hole is smaller than that of the second through hole. The second porous component includes a second main body and a third through hole and a fourth through hole penetrating the second main body. The third through hole is located at the upper part of the second main body, and the fourth through hole is located at the lower part of the second main body. The diameter of the third through hole is larger than that of the fourth through hole. Thus, when the refrigerant flows through the first porous component in the inlet pipe, since the refrigerant is in a liquid state at this time, most of the refrigerant will enter the annular pipe through the second through-hole with a large lower diameter and flow to the delivery pipe away from the inlet pipe, while a small portion of the fluid will enter the annular pipe through the first through-hole with a small upper diameter and flow to the delivery pipe closer to the inlet pipe. This allows the delivery pipe away from the inlet pipe to quickly store approximately the same amount of refrigerant as the delivery pipe closer to the inlet pipe, thereby ensuring that the flow rate of refrigerant in each delivery pipe remains basically consistent. When the refrigerant flows through the delivery pipe, it absorbs heat from the main body of the paraxylene crystallizer, and after vaporization, it enters the annular pipe above. When the vaporized refrigerant flows through the second porous component in the outlet pipe, most of the refrigerant in the annular pipe away from the outlet pipe will flow out through the third through-hole with a large upper diameter, while a small portion of the refrigerant in the annular pipe closer to the outlet pipe will flow out through the fourth through-hole with a small lower diameter, thereby ensuring that the refrigerant outflow time in each delivery pipe is basically the same. The combined effect of the first and second porous components ensures that the inlet and outlet flow rates of the multiple liquid delivery pipes arranged along the circumference of the annular pipe are basically the same at any time, ensuring that the refrigerant is evenly distributed in each liquid delivery pipe. This results in uniform heat transfer effect and basically consistent heat transfer coefficient in each liquid delivery pipe, reducing the energy consumption of the crystallizer and improving the crystallization efficiency. Attached Figure Description

[0017] 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 of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 A schematic diagram of a cold-side jacket structure provided by this utility model; Figure 2 for Figure 1 A schematic diagram of the AA section of the intercooler side jacket structure; Figure 3 This is a schematic diagram of the cross-section of the first porous component; Figure 4 This is a schematic diagram of the cross-section of the second porous component; Figure 5 A schematic diagram of another cold-side jacket structure provided by this utility model.

[0019] Explanation of icon numbers: 100-Cold side jacket structure; 1- Circular pipe; 2-Infusion tubing; 3-Inlet pipe; 31-First porous component; 311-First main body; 312-First through hole; 313-Second through hole; 4-Outlet pipe; 41-Second porous component; 411-Second main body; 412-Third through hole; 413-Fourth through hole.

[0020] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0024] Currently, industrial paraxylene crystallizers primarily remove heat from the PX crystallization process indirectly through refrigerant transfer within the cold-side jacket structure. The inventors discovered that after the refrigerant fluid enters the annular pipe through the inlet pipe, the flow rate in the pipes closer to the inlet pipe is greater than that in the pipes farther from the inlet pipe due to differences in distance between the multiple delivery pipes. This results in uneven distribution of the refrigerant fluid within the multiple delivery pipes, leading to uneven cooling and consequently, high energy consumption and low crystallization efficiency in the paraxylene crystallizer.

[0025] To solve the above problems, the inventors attempted to design a cold-side jacket structure and unexpectedly discovered that by setting a first porous component in the inlet pipe and a second porous component in the outlet pipe, they could solve the problem. When the refrigerant flows through the first porous component in the inlet pipe, since the refrigerant is in a liquid state at this time, most of the refrigerant will enter the annular pipe through the second through-hole with a larger lower diameter and flow to the delivery pipe away from the inlet pipe. A small portion of the fluid will enter the annular pipe through the first through-hole with a smaller upper diameter and flow to the delivery pipe closer to the inlet pipe. This allows the delivery pipe away from the inlet pipe to quickly store approximately the same amount of refrigerant as the delivery pipe closer to the inlet pipe, thus ensuring that the flow rate of refrigerant in each delivery pipe remains basically consistent. When the refrigerant flows through the delivery pipe, it absorbs heat from the main body of the paraxylene crystallizer, and after vaporization, it enters the annular pipe above. When the vaporized refrigerant flows through the second porous component in the outlet pipe, most of the refrigerant in the annular pipe away from the outlet pipe will flow out through the third through-hole with a larger upper diameter, while a small portion of the refrigerant in the annular pipe closer to the outlet pipe will flow out through the fourth through-hole with a smaller lower diameter, thus ensuring that the refrigerant outflow time in each delivery pipe is basically the same. The combined effect of the first and second porous components ensures that the inlet and outlet flow rates of the multiple liquid delivery pipes arranged along the circumference of the annular pipe are basically the same at any time, ensuring that the refrigerant is evenly distributed in each liquid delivery pipe. This results in uniform heat transfer effect and basically consistent heat transfer coefficient in each liquid delivery pipe, reducing the energy consumption of the crystallizer and improving the crystallization efficiency.

[0026] This utility model provides a cold-side jacket structure. Figures 1 to 5 This is a specific embodiment of the cold-side jacket structure provided by this utility model.

[0027] Please see Figures 1 to 2 The present invention provides a cold-side jacket structure 100 for a paraxylene crystallizer. The cold-side jacket structure 100 includes an annular pipe 1, a delivery pipe 2, an inlet pipe 3, and an outlet pipe 4. Two annular pipes 1 are provided, arranged vertically and spaced apart from each other. Multiple delivery pipes 2 are provided, arranged between two annular pipes 1 and along the circumference of the annular pipes 1, with both ends of each delivery pipe 2 connected to two annular pipes 1 respectively. The inlet pipe 3 is connected to the lower annular pipe 1, and the inlet pipe 3 has a first porous component 31 inside. (See reference...) Figure 3The first porous component 31 includes a first main body 311 and a first through hole 312 and a second through hole 313 penetrating the first main body 311. The first through hole 312 is located at the upper part of the first main body 311, and the second through hole 313 is located at the lower part of the first main body 311. The diameter of the first through hole 312 is smaller than the diameter of the second through hole 313. The outlet pipe 4 communicates with the annular pipe 1 located above. The outlet pipe 4 is provided with a second porous component 41 inside. (See reference...) Figure 4 The second porous component 41 includes a second main body 411 and a third through hole 412 and a fourth through hole 413 penetrating the second main body 411. The third through hole 412 is located in the upper part of the second main body 411, and the fourth through hole 413 is located in the lower part of the second main body 411. The diameter of the third through hole 412 is larger than the diameter of the fourth through hole 413.

[0028] In the technical solution provided by this utility model, when the refrigerant flows through the first porous component 31 in the inlet pipe 3, since the refrigerant is in a liquid state at this time, most of the refrigerant will enter the annular pipe 1 through the second through hole 313 with a large lower diameter and flow to the infusion pipe 2 away from the inlet pipe 3. A small portion of the fluid will enter the annular pipe 1 through the first through hole 312 with a small upper diameter and flow to the infusion pipe 2 near the inlet pipe 3. This allows the infusion pipe 2 away from the inlet pipe 3 to quickly store essentially the same refrigerant as the infusion pipe 2 near the inlet pipe 3, thereby ensuring that each infusion pipe... The flow rate of the refrigerant in each of the two inlet and outlet pipes is kept relatively constant. When the refrigerant flows through the inlet pipe 2, it absorbs heat from the outer wall of the xylene crystallizer body, vaporizes, and then enters the upper annular pipe 1. When the vaporized refrigerant flows through the second porous component 41 in the outlet pipe 4, most of the refrigerant in the annular pipe 1, far from the outlet pipe 4, flows out through the upper, larger-diameter third through-hole 412, while a smaller portion of the refrigerant in the annular pipe 1, closer to the outlet pipe 4, flows out through the lower, smaller-diameter fourth through-hole 413. This ensures that the refrigerant outflow time in each inlet pipe 2 is essentially the same. Through the synergistic effect of the first porous component 31 and the second porous component 41, the inlet and outlet flow rates of the multiple inlet pipes 2 arranged along the circumference of the annular pipe 1 are kept relatively consistent at all times. This ensures that the refrigerant is evenly distributed in each inlet pipe 2, resulting in uniform heat transfer and a relatively consistent heat transfer coefficient, reducing the energy consumption of the crystallizer and improving the crystallization efficiency.

[0029] It should be noted that the diameters of the first through hole 312, the second through hole 313, the third through hole 412, and the fourth through hole 413 can be set according to actual conditions. For example, in this embodiment, the diameters of the first through hole 312 and the fourth through hole 413 are 5mm, and the diameters of the second through hole 313 and the third through hole 412 are 10mm.

[0030] The following will describe, by way of example, a further specific implementation or refinement of the cold-side jacket structure 100, in order to further improve its efficiency, reliability or for other improvement considerations.

[0031] In some embodiments, see Figure 3 Multiple first through holes 312 and multiple second through holes 313 are provided. The multiple first through holes 312 are spaced apart on the upper part of the first main body 311, and the multiple second through holes 313 are spaced apart on the middle and lower parts of the first main body 311. Thus, by having multiple second through holes 313 located on the middle and lower parts of the first main body 311 work together, most of the refrigerant can enter the area of ​​the lower annular pipe 1 away from the inlet pipe 3 more evenly, rather than rushing in from a single point and causing an impact that would affect the uniform flow of the refrigerant. Similarly, the multiple first through holes 312 located on the upper part of the first main body 311 can evenly distribute a small portion of the refrigerant to the area of ​​the lower annular pipe 1 near the inlet pipe 3. This ensures uniform flow of refrigerant throughout the entire circumference of the lower annular pipe 1, thus laying a good foundation for subsequent flow into each infusion pipe 2.

[0032] See Figure 4 Multiple third through holes 412 and multiple fourth through holes 413 are provided. The multiple third through holes 412 are spaced apart at the upper and middle parts of the second main body 411, and the multiple fourth through holes 413 are spaced apart at the lower part of the second main body 411. Thus, the multiple third through holes 412 located at the upper and middle parts of the second main body 411 can more effectively guide the majority of fluid away from the outlet pipe 4 to flow out; while the multiple fourth through holes 413 located at the lower part of the second main body 411 can more evenly guide the smaller portion of fluid near the outlet pipe 4 to flow out. This ensures that the refrigerant outflow time in each infusion tube 2 is basically consistent.

[0033] In some embodiments, see Figure 3 and Figure 4 The first porous component 31 and the second porous component 41 are arranged in a mirror-symmetric manner about a horizontal reference plane. In this way, the first porous component 31 and the second porous component 41 can be designed as identical parts, and can be installed in different directions when placed in the inlet pipe 3 or the outlet pipe 4, which reduces the types of parts and lowers the mold opening and production costs.

[0034] In some embodiments, see Figure 1The system comprises two inlet pipes 3 and two outlet pipes 4. The inlet pipes 3 are located on opposite sides of the lower annular pipe 1, and the outlet pipes 4 are located on opposite sides of the upper annular pipe 1. The two inlet pipes 3 and two outlet pipes 4 correspond vertically. This design ensures that the refrigerant flow rate at the inlet and outlet of each infusion pipe 2 is essentially consistent, while also effectively shortening the time it takes for each infusion pipe 2 to reach the same flow rate, thus improving the cooling effect.

[0035] In some embodiments, see Figure 2 The infusion tube 2 is a semi-circular tube, with its arc-shaped portion facing away from the p-xylene crystallizer. This allows the flat portion of the semi-circular tube facing away from the arc to fit snugly against the crystallizer. The flat portion fits the crystallizer better than the arc portion, increasing the effective heat transfer area and improving the heat transfer efficiency of the refrigerant, thereby reducing energy consumption and increasing crystallization efficiency. Furthermore, multiple infusion tubes 2 are connected sequentially along the circumference of the annular tube 1. This allows the flat portions of each semi-circular tube to collectively form a continuous, uninterrupted cylindrical heat transfer surface, completely fitting against the outer wall of the crystallizer body. This avoids uneven heat transfer and heat loss caused by gaps, ensures uniform cooling of the crystallizer wall, reduces energy consumption, and enables uniform PX crystallization.

[0036] In some embodiments, see Figure 5 Multiple cold-side jacket structures 100 are provided and connected sequentially along the vertical direction. This modular design can adapt to xylene crystallizers of different heights. Furthermore, since each cold-side jacket structure 100 is equipped with an independent inlet pipe 3 and outlet pipe 4, different temperatures can be set at different height sections of the crystallizer as needed. In addition, when a leak occurs in a certain cold-side jacket structure 100 or maintenance is required, only that section of the cold-side jacket structure 100 needs to be repaired or maintained, reducing the difficulty of maintenance and repair. In practical applications, multiple cold-side jacket structures 100 are installed sequentially along the vertical direction on the outer wall of the xylene crystallizer body. In this embodiment, the number of cold-side jacket structures 100 is 4 to 8.

[0037] This utility model also provides a paraxylene crystallizer, including a crystallizer body and the aforementioned cold-side jacket structure 100, wherein the cold-side jacket structure 100 is sleeved on the outer side of the crystallizer body. Specifically, the crystallizer body is cylindrical, and the cold-side jacket structure 100 is sleeved on the outer wall of the crystallizer body. After the refrigerant enters the liquid delivery pipe 2 from the inlet pipe 3, it will exchange heat with the outer wall of the crystallizer body and undergo a vaporization reaction. Then, the heat is carried out through the outlet pipe 4, thereby completing the cooling of the crystallizer.

[0038] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the concept of the present utility model and using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present utility model.

Claims

1. A cold-side jacket structure, characterized in that, For a paraxylene crystallizer, the cold-side jacket structure includes: an annular pipe, a delivery pipe, an inlet pipe, and an outlet pipe; Two annular tubes are provided, and the two annular tubes are arranged vertically at a distance from each other; Multiple infusion tubes are provided, and the multiple infusion tubes are arranged between two annular tubes and along the circumference of the annular tubes. The two ends of each infusion tube are respectively connected to the two annular tubes. The inlet pipe is connected to the annular pipe located below. The inlet pipe is provided with a first porous component. The first porous component includes a first main body and a first through hole and a second through hole penetrating the first main body. The first through hole is located at the upper part of the first main body, and the second through hole is located at the lower part of the first main body. The diameter of the first through hole is smaller than the diameter of the second through hole. The outlet pipe is connected to the annular pipe located above. The outlet pipe is provided with a second porous component. The second porous component includes a second main body and a third through hole and a fourth through hole penetrating the second main body. The third through hole is located in the upper part of the second main body, and the fourth through hole is located in the lower part of the second main body. The diameter of the third through hole is larger than the diameter of the fourth through hole.

2. The cold-side jacket structure as described in claim 1, characterized in that, Multiple first through holes and multiple second through holes are provided. Multiple first through holes are arranged at intervals on the upper part of the first main body, and multiple second through holes are arranged at intervals on the middle and lower parts of the first main body. Multiple third through holes and multiple fourth through holes are provided. The multiple third through holes are arranged at intervals in the upper and middle parts of the second main body, and the multiple fourth through holes are arranged at intervals in the lower part of the second main body.

3. The cold-side jacket structure as described in claim 1 or 2, characterized in that, The first porous component and the second porous component are arranged in a mirror-symmetric manner about a horizontal reference plane.

4. The cold-side jacket structure as described in claim 1, characterized in that, Two inlet pipes and two outlet pipes are provided. The inlet pipes are respectively provided on the opposite sides of the lower annular pipe, and the outlet pipes are respectively provided on the opposite sides of the upper annular pipe. The two inlet pipes and the two outlet pipes correspond one-to-one in the vertical direction.

5. The cold-side jacket structure as described in claim 1, characterized in that, The infusion tube is a semi-circular tube, and the arc portion of the semi-circular tube is away from the xylene crystallizer.

6. The cold-side jacket structure as described in claim 5, characterized in that, The sides of multiple infusion tubes are connected sequentially along the circumference of the annular tube.

7. The cold-side jacket structure as described in claim 1, characterized in that, The diameter of the first through hole is 5 mm, and the diameter of the second through hole is 10 mm.

8. The cold-side jacket structure as described in claim 1, characterized in that, The diameter of the third through hole is 10 mm, and the diameter of the fourth through hole is 5 mm.

9. The cold-side jacket structure as described in claim 1, characterized in that, Multiple cold-side jacket structures are provided and connected sequentially along the vertical direction.

10. A paraxylene crystallizer, characterized in that, include: The crystallizer body and the cold-side jacket structure as described in any one of claims 1-9, wherein the cold-side jacket structure is sleeved on the outside of the crystallizer body.

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