U-shaped tubular reactor

Abstract

The utility model discloses a U-shaped tubular reactor, which comprises a tube box, a shell pass cylinder, a fixed tube plate, a baffle plate and a U-shaped heat exchange tube, the shell pass cylinder comprises a straight tube section and an end socket, one of a shell pass medium inlet and a shell pass medium outlet of the shell pass cylinder is arranged at the front end of the straight tube section, and the other one of the shell pass medium inlet and the shell pass medium outlet of the shell pass cylinder is arranged at the end socket. By changing the flowing path of the shell pass medium, the downstream path of the shell pass medium passes through the expansion telescopic space, and the shell pass medium retained in the expansion telescopic space is taken out of the shell pass cylinder, so that the problem that the concentration distribution and retention time of the medium in the shell pass are influenced due to backmixing and retention of the shell pass medium in the expansion telescopic space is solved; the reaction effect and the heat exchange efficiency are influenced; and the stability of the fluid in the reactor cylinder is further ensured.

Description

Technical Field

[0001] This utility model relates to the field of thermochemical reaction technology, specifically to a U-shaped tubular reactor. Background Technology

[0002] The main limiting factor for thermochemical reactions is the heat exchange efficiency between the energy and reagent systems. Higher exchange efficiency between the heat transfer fluid and the reagent system leads to better reaction results. Thermochemical reactors are core equipment in the chemical industry. During thermochemical reactions, engineering problems such as strong exothermic reactions, heat removal, backmixing, and leakage are generally present. These issues are key considerations and solutions during the design and optimization of thermochemical reactors. Currently, shell-and-tube reactors are very commonly used as thermochemical reactors.

[0003] Among common tubular reactors, the U-shaped tubular reactor has a double tube pass, a longer flow path, higher flow velocity, and better heat transfer performance. Moreover, the U-shaped tubular reactor is a floating reactor, and its tube bundle can freely expand and contract within the shell-side cylinder, without generating thermal stress due to temperature differences between the tubes and the shell. It has good thermal compensation performance and strong pressure resistance. The tube bundle can be extracted from the shell-side cylinder, which is convenient for maintenance and cleaning. It also has a simple structure and low cost.

[0004] Because U-tube reactors are floating reactors, their shell-side cylinders need to provide expansion and contraction space for their tube bundles. Therefore, the shell-side cylinders of U-tube reactors extend into a cap at the end of the tube bundles to provide this expansion and contraction space. However, in existing U-tube reactors, the shell-side medium inlet / outlet is located at the front end of the straight tube section of the shell-side cylinder, while the shell-side medium outlet / inlet is located at the rear end of the straight tube section. The cap is not in the co-current flow path of the shell-side medium, causing backmixing and retention of the shell-side medium within the cap in the expansion and contraction space. This not only affects the concentration distribution and residence time of the medium within the shell, thus impacting the reaction efficiency, but also affects the heat exchange efficiency of the fluid in the thermochemical reactor because heat cannot be carried out of the reactor cylinder in a timely manner. Furthermore, prolonged fluid retention in the reactor cylinder easily leads to scaling on the inner wall of the reactor cylinder, further reducing the heat exchange efficiency of the thermochemical reactor. In addition, in some thermochemical reaction experiments, it is necessary to ensure that the temperature of the fluid is stable within a set temperature range. This is achieved by calculating the fluid flow rate and heat transfer ratio, and controlling the temperature of the fluid flowing out of the reactor shell by the heat transfer time inside the reactor shell, thus stabilizing it within the set temperature range. However, when the fluid stagnates in the reaction dead zone, its heat transfer time increases and exceeds the set time, which can easily cause the temperature of some fluid flowing out of the reactor shell to exceed the set temperature range, which is not conducive to subsequent reactions.

[0005] Therefore, there is an urgent need to provide a U-tube reactor that is free from backmixing and stagnation and has a uniform fluid temperature, in order to solve the technical problem that the existing U-tube reactor has a reaction dead zone, which causes fluid backmixing and stagnation, affecting heat exchange efficiency and fluid stability. Utility Model Content

[0006] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a U-shaped tubular reactor that is free from backmixing and stagnation and has a uniform fluid temperature. This invention can solve the technical problem that existing U-shaped tubular reactors have reaction dead zones that cause fluid backmixing and stagnation, affecting the heat exchange efficiency and fluid stability of the U-shaped tubular reactor.

[0007] To achieve the above technical objectives, the present invention provides a U-shaped tubular reactor, which includes: a tube box, a shell-side cylinder, a fixed tube sheet, a baffle plate, and U-shaped heat exchange tubes. The shell-side cylinder includes a straight tube section and a head. One of the shell-side medium inlet and the shell-side medium outlet of the shell-side cylinder is located at the front end of the straight tube section, and the other is located at the head.

[0008] Preferably, the shell-side medium inlet / outlet is located at the end of the head along the extension line of the straight pipe section axis.

[0009] Preferably, the baffle is a spiral baffle, which is fitted onto the tube body of the U-shaped heat exchanger tube.

[0010] Preferably, the inlet / outlet direction of the shell-side medium is set along the tangent direction of the head, and the tangent direction is consistent with the tangent direction of the spiral baffle.

[0011] Preferably, a spiral sealing plug is provided between the fixed tube sheet and the spiral baffle.

[0012] Preferably, the spiral sealing plug has a spiral sealing surface, and the spiral curvature of the spiral sealing surface is consistent with the spiral curvature of the spiral baffle.

[0013] Preferably, the starting point of the spiral sealing surface is set relative to the shell-side medium inlet / outlet.

[0014] Preferably, a radial sealing surface is formed on the back side of the starting point of the spiral sealing surface, with one end of the radial sealing surface connected to the starting point of the spiral sealing surface and the other end connected to the ending point of the spiral sealing surface.

[0015] Preferably, the axial outer peripheral surface of the spiral sealing plug has a circumferential sealing surface, which extends along the axial direction of the shell-side cylinder, with one end connected to the spiral sealing surface and the other end extending to the fixed tube sheet.

[0016] Preferably, the end cap is one of the following: elliptical end cap, dished end cap, spherical end cap, conical end cap, eccentric conical end cap, variable diameter conical end cap, flat cap, forged constricted end cap, or flanged convex end cap.

[0017] Compared with the prior art, the beneficial effects of this utility model include:

[0018] The U-shaped tubular reactor of this invention has its shell-side medium inlet / outlet located at the front end of a straight pipe section, and its shell-side medium outlet / inlet located at the head. This alters the flow path of the shell-side medium, allowing it to flow through the expansion and contraction space. This carries away the shell-side medium retained within the expansion and contraction space, thus solving the problem of backmixing and retention of the shell-side medium in the expansion and contraction space affecting the concentration distribution and residence time of the medium within the shell, thereby impacting reaction efficiency and heat exchange efficiency. Furthermore, it ensures the stability of the fluid within the reactor shell. Preferably, the shell-side medium inlet / outlet is located on the extended axis of the straight pipe section to ensure that the shell-side medium's flow path passes through the entire expansion and contraction space within the head, minimizing the problem of dead zones.

[0019] The U-shaped tubular reactor of this invention uses a spiral baffle to guide the shell-side medium to swirl, forming a spiral plunger flow. This solves the problem of numerous dead zones in the shell-side medium along the baffle path, as well as the problems of turbulence and back mixing that occur during the baffle process. Furthermore, a spiral sealing plug is provided between the fixed tube sheet and the spiral baffle to seal the dead zone on the back side of the spiral baffle end, thus comprehensively optimizing the problem of dead zones in the shell-side medium.

[0020] The U-shaped tubular reactor described in this utility model, based on the swirling characteristics of the spiral baffle, sets the inlet / outlet direction of the shell-side medium along the tangent direction of the head, which is consistent with the tangent direction of the spiral baffle. This reduces the outflow resistance of the shell-side medium and improves the operational stability of the shell-side cylinder; or it provides initial swirling power to the shell-side medium, allowing it to flow smoothly into the spiral baffle. Attached Figure Description

[0021] Figure 1 This is an overall cross-sectional view of the U-shaped tubular reactor described in this embodiment of the present invention.

[0022] Figure 2 yes Figure 1 A cross-sectional view of the U-shaped tubular reactor after the positions of the shell-side medium inlet and shell-side medium outlet have been swapped.

[0023] Figure 3 This is a partial cross-sectional view of the U-shaped tubular reactor described in an embodiment of this utility model.

[0024] Figure 4 This is a partially unfolded view of the U-shaped tubular reactor described in an embodiment of this utility model.

[0025] Figure 5 This is a schematic diagram of the spiral sealing plug in the U-shaped tubular reactor described in this embodiment of the utility model.

[0026] Figure 6 This is a schematic diagram of another modified structure of the U-shaped tubular reactor described in this embodiment of the present invention.

[0027] Figure 7 yes Figure 6 A schematic diagram of the deformed structure of a U-shaped tubular reactor after the positions of the shell-side medium inlet and shell-side medium outlet are swapped.

[0028] The components in the attached diagram are labeled as follows:

[0029] 1. Tube box; 2. Shell side shell; 3. Fixed tube sheet; 4. U-shaped heat exchange tube; 201. Shell side medium inlet; 202. Shell side medium outlet; 21. Straight tube section; 22. End cap; 5. Spiral baffle; 6. Spiral sealing plug; 61. Spiral sealing surface; 62. Radial sealing surface; 63. Circumferential sealing surface. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0031] In existing U-tube reactors, because the end cap 22 is not in the co-current path of the shell-side medium, the shell-side medium inside the end cap 22 causes back mixing and stagnation in the expansion and contraction space, which affects the heat exchange efficiency and fluid stability of the U-tube reactor.

[0032] Based on this, the present invention provides a U-shaped tubular reactor, which includes: a tube box 1, a shell-side cylindrical body 2, a fixed tube sheet 3, baffles, and U-shaped heat exchange tubes 4. Figure 1 and Figure 3 As shown, the tube box 1 and the shell-side cylinder 2 are arranged coaxially and opposite to each other. A fixed tube sheet 3 is positioned between the tube box 1 and the shell-side cylinder 2. The ends of the U-shaped heat exchange tubes 4 pass through baffles and are fixedly connected to the fixed tube sheet 3. The shell-side cylinder 2 is fitted over the outside of the U-shaped heat exchange tubes 4. Figure 1 and Figure 3 As shown, the shell-side cylinder 2 includes a straight pipe section 21 and a head 22. The tube body of the U-shaped heat exchange tube 4 is disposed in the straight pipe section 21. The head 22 is an arc-shaped hollow cavity connected to the straight pipe section 21. There is a free space between the end of the tube body of the U-shaped heat exchange tube 4 and the inner wall of the head 22. This free space is the expansion and contraction space of the U-shaped heat exchange tube 4.

[0033] The aforementioned end cap can be understood as an end component that closes the end of the shell-side cylinder 2 and has expansion and contraction space; in some preferred embodiments, the end cap 22 is one of the following: elliptical end cap, dished end cap, spherical end cap, conical end cap, eccentric conical end cap, variable diameter conical end cap, flat cover, forged shrinkage end cap, or flanged convex end cap.

[0034] The shell-side medium forms a flow path between the shell-side medium inlet 201 and the shell-side medium outlet 202. To prevent the shell-side medium from stagnating in the expansion and contraction space of the head 22, one of the shell-side medium inlet 201 and the shell-side medium outlet 202 of the shell-side cylinder 2 is located at the front end of the straight pipe section 21, and the other is located at the head 22. This allows the shell-side medium to flow through the expansion and contraction space, carrying away the shell-side medium stagnating in the expansion and contraction space, thus solving the problem that backmixing and stagnation of the shell-side medium in the expansion and contraction space affects the concentration distribution and residence time of the medium in the shell-side, thereby affecting the reaction effect and heat exchange efficiency; and further ensuring the stability of the fluid inside the reactor cylinder. Specifically, as follows... Figure 1 As shown, in some preferred embodiments, the shell-side medium inlet 201 of the shell-side cylinder 2 can be located at the front end of the straight pipe section 21, and the shell-side medium outlet 202 can be located at the end cap 22. For example... Figure 2 As shown, in some other preferred embodiments, the shell-side medium outlet 202 of the shell-side cylinder 2 can also be located at the front end of the straight pipe section 21, and the shell-side medium inlet 201 can be located at the end cap 22.

[0035] In some preferred embodiments, the shell-side medium inlet / outlet can be located on the extended axis of the straight pipe section 21 to ensure that the downstream flow path of the shell-side medium can pass through the entire expansion and contraction space within the head 22, minimizing the problem of flow dead zones. For example... Figure 1 and Figure 3 As shown, the shell-side medium inlet 201 of the shell-side cylinder 2 is located perpendicular to the axis of the straight pipe section 21 at the front end of the straight pipe section 21, and the shell-side medium outlet 202 is located along the extension line of the axis of the straight pipe section 21 at the end of the head 22. Correspondingly, when the shell-side medium outlet 202 of the shell-side cylinder 2 is located perpendicular to the axis of the straight pipe section 21 at the front end of the straight pipe section 21, the shell-side medium inlet 201 is located along the extension line of the axis of the straight pipe section 21 at the end of the head 22.

[0036] It is worth noting that either arc-shaped baffles or spiral baffles can be used. To further optimize the flow dead zone problem in the U-tube reactor, in some preferred embodiments, spiral baffles 5 are used inside the shell-side cylinder 2 to guide the shell-side medium into swirling flow, forming a spiral plunger flow. This solves the problem of numerous flow dead zones in the shell-side medium along the baffle path, and also addresses the turbulence and backmixing problems that occur during the baffle process. Compared to arc-shaped baffles, this significantly improves the heat exchange reaction efficiency. Figure 3As shown, in the shell-side cylindrical body 2, a spiral baffle 5 is fitted onto the tube body of the U-shaped heat exchange tube 4. In some preferred embodiments, the inner spiral line of the spiral baffle 5 tends to be straight, that is, the inner diameter of the spiral baffle 5 is almost zero, which cooperates with the inner wall of the shell-side cylindrical body 2 to form a sealed continuous spiral baffle channel with no leakage in the center, further improving the heat exchange reaction efficiency of the U-shaped tubular reactor.

[0037] Building upon the optimization of the flow dead zone using the spiral baffle 5, a further step is taken: a spiral sealing plug 6 is installed at the end of the spiral baffle 5 to seal the flow dead zone on the back side of the end of the spiral baffle 5. For example... Figure 3 and Figure 5 As shown, in some preferred embodiments, a spiral sealing plug 6 is disposed between the fixed tube sheet 3 and the spiral baffle 5. It has a spiral sealing surface 61 on its fluid-facing side, the spiral curvature of which matches the spiral curvature of the spiral baffle 5, and the starting point of the spiral sealing surface 61 is positioned relative to the shell-side medium inlet / outlet. The spiral sealing plug 6 is smoothly connected to the spiral baffle 5 via the spiral sealing surface 61, guiding the shell-side medium to flow smoothly along its spiral flow path to the shell-side medium inlet / outlet. To prevent the shell-side medium from continuing to flow into the flow dead zone on the back side of the spiral baffle 5, the spiral sealing plug 6 forms a radial sealing surface 62 on its back side at the starting point of the spiral sealing surface 61. Figure 4 and Figure 5 As shown, one end of the radial sealing surface 62 is connected to the starting point of the stroke of the spiral sealing surface 61, and the other end is connected to the ending point of the stroke of the spiral sealing surface 61, restricting the flow of the shell-side medium into the reaction dead zone on the back side of the spiral flow channel. Simultaneously, a circumferential sealing surface 63 is formed on the axial outer circumferential surface of the spiral sealing plug 6, as shown... Figure 5 As shown, the circumferential sealing surface 63 extends along the axial direction of the shell-side cylinder 2, with one end connected to the spiral sealing surface 61 and the other end extending to the fixed tube sheet 3, to seal the outer circumferential surface of the spiral sealing surface 61. Through the cooperation of the radial sealing surface 62 and the circumferential sealing surface 63, the flow dead zone on the back side of the spiral surface is sealed, further optimizing the problem of the flow dead zone in the shell-side cylinder 2.

[0038] Based on the swirling characteristics of the helical baffle 5, the shell-side medium forms a helical plunger flow within the shell-side cylinder 2 under the guidance of the helical baffle 5. To adapt to the flow pattern of the shell-side medium, the inlet / outlet directions of the shell-side medium can be set along the tangential direction of the end cap 22, which is consistent with the tangential direction of the helical baffle 5. For example... Figure 6As shown, in some preferred embodiments, the shell-side medium inlet 201 of the shell-side cylinder 2 is disposed perpendicular to the axis of the straight pipe section 21 at the front end of the straight pipe section 21, and the shell-side medium outlet 202 is disposed at the end of the end cap 22 and extends along the tangential direction of the end cap 22, which is consistent with the tangential direction of the spiral baffle 5. In this case, the shell-side medium flows smoothly out along the tangential direction of the shell-side cylinder 2 under the action of swirling flow, with low outflow resistance and higher operational stability of the shell-side cylinder 2. Correspondingly, as... Figure 7 As shown, in some preferred embodiments, when the shell-side medium outlet 202 of the shell-side cylinder 2 is disposed perpendicular to the axis of the straight pipe section 21 at the front end of the straight pipe section 21, the shell-side medium inlet 201 is disposed at the end of the end cap 22 and extends along the tangential direction of the end cap 22, the tangential direction of which is consistent with the tangential direction of the spiral baffle 5. At this time, the shell-side medium flows smoothly in along the tangential direction of the shell-side cylinder 2, providing initial swirling power for the shell-side medium, so that the shell-side medium can flow smoothly into the spiral baffle 5.

[0039] In summary, the U-shaped tubular reactor provided by this embodiment of the invention has the shell-side medium inlet / outlet of the shell-side cylinder 2 located at the front end of the straight pipe section 21, and the shell-side medium outlet / inlet located at the end cap 22. This changes the flow path of the shell-side medium, allowing the downstream flow path of the shell-side medium to pass through the expansion and contraction space, carrying the shell-side medium retained in the expansion and contraction space out of the shell-side cylinder 2. This solves the problem that the backmixing and retention of the shell-side medium in the expansion and contraction space affects the concentration distribution and residence time of the medium in the shell-side, thereby affecting the reaction effect and heat exchange efficiency. Furthermore, it ensures the stability of the fluid inside the reactor cylinder.

[0040] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A U-shaped tubular reactor, characterized in that, include: The tube box, shell-side cylinder, fixed tube sheet, baffle plate, and U-shaped heat exchange tubes are provided. The shell-side cylinder includes a straight tube section and a head. One of the shell-side medium inlet and shell-side medium outlet of the shell-side cylinder is located at the front end of the straight tube section, and the other is located at the head.

2. The U-shaped tubular reactor according to claim 1, characterized in that, The shell-side medium inlet / outlet is located at the end of the head along the extension line of the straight pipe section axis.

3. The U-shaped tubular reactor according to claim 1, characterized in that, The baffle is a spiral baffle, which is fitted onto the tube body of the U-shaped heat exchanger tube.

4. The U-shaped tubular reactor according to claim 3, characterized in that, The inlet / outlet direction of the shell-side medium is set along the tangent direction of the head, and the tangent direction is consistent with the tangent direction of the spiral baffle.

5. The U-shaped tubular reactor according to claim 3, characterized in that, A spiral sealing plug is provided between the fixed tube sheet and the spiral baffle.

6. The U-shaped tubular reactor according to claim 5, characterized in that, The spiral sealing plug has a spiral sealing surface, and the spiral curvature of the spiral sealing surface is consistent with the spiral curvature of the spiral baffle.

7. The U-shaped tubular reactor according to claim 6, characterized in that, The starting point of the spiral sealing surface is set relative to the shell-side medium inlet / outlet.

8. The U-shaped tubular reactor according to claim 7, characterized in that, A radial sealing surface is formed on the back side of the starting point of the spiral sealing surface. One end of the radial sealing surface is connected to the starting point of the spiral sealing surface, and the other end is connected to the ending point of the spiral sealing surface.

9. The U-shaped tubular reactor according to claim 6, characterized in that, The spiral sealing plug has a circumferential sealing surface formed on its axial outer peripheral surface. The circumferential sealing surface extends along the axial direction of the shell-side cylinder, with one end connected to the spiral sealing surface and the other end extending to the fixed tube sheet.

10. The U-shaped tubular reactor according to claim 1, characterized in that, The head is one of the following: elliptical head, dished head, spherical head, conical head, eccentric conical head, variable diameter conical head, flat cover, forged constricted head, or flanged convex head.

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