U-shaped tubular reactor

Abstract

The invention 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] The invention relates to the technical field of thermochemical reactions, and in particular to a U-shaped tubular reactor. Background Art

[0002] The main limiting factor of thermochemical reactions is the heat exchange efficiency between the energy and reagent systems. The higher the exchange efficiency between the heat transfer fluid and the reagent system, the better the reaction effect. Thermochemical reactors are core equipment in the chemical industry. In the process of thermochemical reactions, there are generally engineering problems such as strong heat release, heat removal, back mixing, and leakage. These problems are the key points that need to be considered and solved when optimizing the design of thermochemical reactors. At present, it is very common to use shell and tube reactors as thermochemical reactors.

[0003] Among the common tubular reactors, the U-type tubular reactor has a double tube pass, a longer flow path, a higher flow rate, and better heat transfer performance. The U-type tubular reactor is a floating reactor, and its tube bundle can freely expand and contract in the shell-side cylinder, and will not generate thermal stress due to the temperature difference between the shell and the tube. It has good thermal compensation performance and strong pressure bearing capacity. The tube bundle can be pulled out from the shell-side cylinder for easy maintenance and cleaning, and has a simple structure and low cost.

[0004] Since the U-type tubular reactor is a floating reactor, its shell-side cylinder needs to provide expansion and contraction space for its tube bundle. Therefore, the shell-side cylinder of the U-type tubular reactor continues to extend a head at the end of the tube bundle to provide expansion and contraction space for the tube bundle. However, the shell-side medium inlet / / outlet of the existing U-type tubular reactor is set at the front end of the straight tube section of the shell-side cylinder, and the shell-side medium outlet / inlet is set at the rear end of the straight tube section of the shell-side cylinder. The head is not on the downstream path of the shell-side medium, causing the shell-side medium in the head to be mixed and retained in the expansion and contraction space, which not only affects the concentration distribution and residence time of the medium in the shell side, and affects the reaction effect, but also affects the heat exchange efficiency of the fluid in the thermochemical reactor because the heat cannot be taken out of the reactor cylinder in time; and the fluid stays in the reactor cylinder for a long time, which is easy to scale 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 the set temperature range. By calculating the flow rate and heat exchange ratio of the fluid, the heat exchange time in the reactor cylinder is used to control the temperature of the fluid outflow and stabilize it within the set temperature range. However, when the fluid is retained in the reaction dead zone, its heat exchange time increases and exceeds the set time, which can easily cause the temperature of some fluids flowing out of the reactor cylinder to exceed the set temperature range, which is not conducive to subsequent reactions.

[0005] Therefore, there is an urgent need to provide a U-shaped tube reactor with no backmixing, no retention and balanced fluid temperature, so as to solve the technical problems that the existing U-shaped tube reactor has a reaction dead zone, causing fluid backmixing and retention, affecting heat exchange efficiency and fluid stability. Summary of the invention

[0006] The object of the present invention is to overcome the above-mentioned technical deficiencies and provide a U-shaped tubular reactor which has no backmixing, no retention and balanced fluid temperature, and can solve the technical problems that the existing U-shaped tubular reactor has a reaction dead zone causing fluid backmixing and retention, affecting the heat exchange efficiency and fluid stability of the U-shaped tubular reactor.

[0007] In order to achieve the above technical objectives, the technical solution of the present invention provides a U-shaped tubular reactor, which includes: a tube box, a shell-side cylinder, a fixed tube sheet, a baffle and a U-shaped heat exchange tube, the shell-side cylinder includes a straight tube section and a head, and one of the shell-side medium inlet and the shell-side medium outlet of the shell-side cylinder is arranged at the front end of the straight tube section, and the other is arranged at the head.

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

[0009] Preferably, the baffle is a spiral baffle, and the spiral baffle is sleeved on the tube body of the U-shaped heat exchange tube.

[0010] Preferably, the inlet and outlet directions of the shell-side medium inlet / outlet are arranged 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 stroke of the spiral sealing surface is arranged relative to the shell-side medium inlet / outlet.

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

[0015] Preferably, the axial outer peripheral surface of the spiral sealing plug is formed with 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 head is one of an elliptical head, a dished head, a spherical head, a conical head, an eccentric conical head, a reducing conical head, a flat cover, a forged shrinking head or a convex head with a flange.

[0017] Compared with the prior art, the beneficial effects of the present invention include:

[0018] The U-shaped tubular reactor of the present invention sets the shell-side medium inlet / outlet of the shell-side cylinder at the front end of the straight tube section, and the shell-side medium outlet / inlet is set at the head; so as to change the flow path of the shell-side medium, so that the downstream path of the shell-side medium passes through the expansion and contraction space, and the shell-side medium retained in the expansion and contraction space is brought out of the shell-side cylinder, thereby solving the problem that the concentration distribution and residence time of the medium in the shell-side are affected by the back mixing and retention of the shell-side medium in the expansion and contraction space, thereby affecting the reaction effect and heat exchange efficiency; and further ensures the stability of the fluid in the reactor cylinder. It is preferred to set the shell-side medium inlet / outlet on the extension line of the straight tube section axis to ensure that the downstream path of the shell-side medium can pass through the entire expansion and contraction space in the head, and avoid the problem of flow dead zone to the greatest extent.

[0019] The U-shaped tubular reactor described in the present invention adopts spiral baffles in the shell-side cylinder to guide the swirl flow of the shell-side medium to form a spiral plug flow; the problem of the shell-side medium having a large number of flow dead zones on the baffle path is solved, and the problems of turbulence and backmixing occurring in the shell-side medium during the baffle process are also solved; and a spiral sealing plug is further provided between the fixed tube sheet and the spiral baffle to seal the flow dead zone on the back side of the end of the spiral baffle, thereby comprehensively optimizing the flow dead zone problem in the shell-side cylinder.

[0020] The U-shaped tubular reactor of the present invention is based on the swirl characteristics of the spiral baffles, and the inlet and outlet directions of the shell-side medium inlet / outlet are arranged along the tangent direction of the head, and the tangent direction is consistent with the tangent direction of the spiral baffles, so that the outflow resistance of the shell-side medium is small and the operation stability of the shell-side cylinder is higher; or the initial swirl power is provided for the shell-side medium, so that the shell-side medium can flow smoothly into the spiral baffles. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0023] Figure 3 It is a partial cross-sectional view of the U-shaped tubular reactor described in an embodiment of the present invention.

[0024] Figure 4 It is a partially expanded view of the U-shaped tubular reactor described in an embodiment of the present invention.

[0025] Figure 5 It is a schematic structural diagram of a spiral sealing plug in a U-shaped tubular reactor described in an embodiment of the present invention.

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

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

[0028] The markings of the components in the accompanying drawings are as follows:

[0029] 1. Pipe box; 2. Shell-side cylinder; 3. Fixed tube sheet; 4. U-shaped heat exchange tube; 201. Shell-side medium inlet; 202. Shell-side medium outlet; 21. Straight pipe section; 22. Head; 5. Spiral baffle; 6. Spiral sealing plug; 61. Spiral sealing surface; 62. Radial sealing surface; 63. Circumferential sealing surface. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] In the existing U-shaped tube reactor, since the head 22 is not on the downstream path of the shell-side medium, the shell-side medium in the head 22 is back-mixed and retained in the expansion and contraction space, affecting the heat exchange efficiency and fluid stability of the U-shaped tube reactor.

[0032] Based on this, the present invention provides a U-shaped tubular reactor, which comprises: a tube box 1, a shell-side cylinder 2, a fixed tube sheet 3, a baffle and a U-shaped heat exchange tube 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, the fixed tube sheet 3 is arranged between the tube box 1 and the shell-side cylinder 2, the tube end of the U-shaped heat exchange tube 4 passes through the baffle and is fixedly connected to the fixed tube sheet 3, and the shell-side cylinder 2 is sleeved on the outer side of the tube body of the U-shaped heat exchange tube 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 arranged 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 vacant space between the tube body end of the U-shaped heat exchange tube 4 and the inner wall of the head 22. The vacant space is the expansion and contraction space of the U-shaped heat exchange tube 4.

[0033] The above-mentioned head 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 head 22 is one of an elliptical head, a dish-shaped head, a spherical head, a conical head, an eccentric conical head, a reducing conical head, a flat cover, a forged tightening head or a flanged convex head.

[0034] The shell-side medium forms a flow path between the shell-side medium inlet 201 and the shell-side medium outlet 202. In order to prevent the shell-side medium from being retained 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 arranged at the front end of the straight pipe section 21, and the other is arranged at the head 22. The downstream path of the shell-side medium passes through the expansion and contraction space, and the shell-side medium retained in the expansion and contraction space is brought out of the shell-side cylinder 2, thereby solving the problem that the concentration distribution and residence time of the medium in the shell-side are affected by the back mixing and retention of the shell-side medium in the expansion and contraction space, thereby affecting the reaction effect and heat exchange efficiency; and further ensuring the stability of the fluid in the reactor cylinder. Specifically, Figure 1 As shown, in some preferred embodiments, the shell-side medium inlet 201 of the shell-side cylinder 2 can be arranged at the front end of the straight pipe section 21, and the shell-side medium outlet 202 can be arranged at the head 22. Figure 2 As shown, in other preferred embodiments, the shell-side medium outlet 202 of the shell-side cylinder 2 may be arranged at the front end of the straight pipe section 21 , and the shell-side medium inlet 201 may be arranged at the head 22 .

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

[0036] It is worth noting that the baffles can be arcuate baffles or spiral baffles. In order to further optimize the dead zone problem of the U-shaped tubular reactor, in some preferred embodiments, spiral baffles 5 are used in the shell-side cylinder 2 to guide the swirl of the shell-side medium to form a spiral plug flow; this solves the problem of more dead zones in the baffle path of the shell-side medium, and also solves the problems of turbulence and backmixing of the shell-side medium during the baffle process. Compared with arcuate baffles, it greatly improves the heat exchange reaction efficiency. Figure 3 As shown, in the shell-side cylinder 2, the spiral baffle 5 is sleeved on the tube body of the U-shaped heat exchange tube 4. In some more preferred embodiments, the inner spiral line of the spiral baffle 5 tends to be a straight line, that is, the inner hole diameter of the spiral baffle 5 is almost zero, and cooperates with the inner wall of the shell-side cylinder 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] On the basis of using the spiral baffle 5 to optimize the flow dead zone, further, a spiral sealing plug 6 is provided 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. Figure 3 and Figure 5 As shown, in some preferred embodiments, the spiral sealing plug 6 is disposed between the fixed tube sheet 3 and the spiral baffle 5, and a spiral sealing surface 61 is provided on the side facing the fluid direction. The spiral curvature of the spiral sealing surface 61 is consistent with the spiral curvature of the spiral baffle 5, and the starting point of the stroke of the spiral sealing surface 61 is set relative to the shell-side medium inlet / outlet. The spiral sealing plug 6 is smoothly connected to the spiral baffle 5 through the spiral sealing surface 61 to guide the shell-side medium to flow smoothly along its spiral guide path to the shell-side medium inlet / outlet. In order to prevent the shell-side medium from continuing to flow into the flow dead zone on the back side of the end of the spiral baffle 5, the spiral sealing plug 6 is formed with a radial sealing surface 62 at the starting point of the stroke of the spiral sealing surface 61 toward its back side. As shown Figure 4 and Figure 5 As shown, one end of the radial sealing surface 62 is connected to the starting point of the spiral sealing surface 61, and the other end is connected to the end point of the spiral sealing surface 61, limiting the shell side medium from flowing into the reaction dead zone on the back side of the spiral flow channel. At the same time, the axial outer peripheral surface of the spiral sealing plug 6 is formed with a circumferential sealing surface 63, as shown in FIG. Figure 5 As shown, the circumferential blocking surface 63 extends along the axial direction of the shell-side cylinder 2, one end of which is connected to the spiral sealing surface 61, and the other end extends to the fixed tube sheet 3, so as to block the outer circumferential surface of the spiral sealing surface 61. Through the cooperation of the radial blocking surface 62 and the circumferential blocking surface 63, the flow dead zone on the back side of the spiral surface is blocked, and the flow dead zone problem in the shell-side cylinder 2 is further improved.

[0038] Based on the swirl characteristics of the spiral baffles 5, the shell-side medium forms a spiral plug flow in the shell-side cylinder 2 under the guidance of the spiral baffles 5. In order to adapt to the flow mode of the shell-side medium, the inlet and outlet directions of the shell-side medium can be set along the tangent direction of the head 22, and the tangent direction is consistent with the tangent direction of the spiral baffles 5. Figure 6 As shown, in some preferred embodiments, the shell-side medium inlet 201 of the shell-side cylinder 2 is arranged at the front end of the straight pipe section 21 perpendicular to the axis of the straight pipe section 21, and the shell-side medium outlet 202 is arranged at the end of the head 22 and extends along the tangent direction of the head 22, and its tangent direction is consistent with the tangent direction of the spiral baffle 5. At this time, the shell-side medium flows out smoothly along the tangent direction of the shell-side cylinder 2 under the action of the swirl flow, with small outflow resistance, and the operation stability of the shell-side cylinder 2 is higher. Correspondingly, as Figure 7As shown, in other preferred embodiments, when the shell-side medium outlet 202 of the shell-side cylinder 2 is arranged at the front end of the straight pipe section 21 perpendicular to the axis of the straight pipe section 21, the shell-side medium inlet 201 is arranged at the end of the head 22 and extends along the tangent direction of the head 22, and its tangent direction is consistent with the tangent direction of the spiral baffle 5. At this time, the shell-side medium flows in smoothly along the tangent direction of the shell-side cylinder 2, providing the shell-side medium with initial swirl power, so that the shell-side medium can flow smoothly into the spiral baffle 5.

[0039] In summary, an embodiment of the present invention provides a U-shaped tubular reactor, in which the shell-side medium inlet / outlet of the shell-side cylinder 2 is arranged at the front end of the straight pipe section 21, and the shell-side medium outlet / inlet is arranged at the head 22; so as to change the flow path of the shell-side medium, so that the downstream path of the shell-side medium passes through the expansion and contraction space, and the shell-side medium retained in the expansion and contraction space is brought out of the shell-side cylinder 2, thereby solving the problem that the concentration distribution and residence time of the medium in the shell are affected by the back mixing and retention of the shell-side medium in the expansion and contraction space, thereby affecting the reaction effect and heat exchange efficiency; and further ensuring the stability of the fluid in the reactor cylinder.

[0040] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed as above in the form of preferred embodiments, it is not intended to limit the present invention. Any technical personnel in the field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A U-shaped tubular reactor, characterized in that: include: A tube box, a shell-side cylinder, a fixed tube sheet, a baffle and a U-shaped heat exchange tube, wherein the shell-side cylinder comprises a straight tube section and a head, wherein one of a shell-side medium inlet and a shell-side medium outlet of the shell-side cylinder is arranged at the front end of the straight tube section, and the other is arranged at the head.

2. The U-shaped tubular reactor according to claim 1, characterized in that The shell-side medium inlet / outlet is arranged 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, and the spiral baffle is sleeved on the tube body of the U-shaped heat exchange tube.

4. The U-shaped tubular reactor according to claim 3, characterized in that: The inlet and outlet directions of the shell-side medium inlet / outlet are arranged 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 plate 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 medium inlet / outlet.

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

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

10. The U-shaped tubular reactor according to claim 1, characterized in that: The head is one of an elliptical head, a dished head, a spherical head, a conical head, an eccentric conical head, a reducing conical head, a flat cover, a forged shrinking head or a convex head with a flange.

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