A tubular reactor

Abstract

The utility model relates to the technical field of reactors, in particular to a tubular reactor, comprising a shell and an upper tube plate and a lower tube plate arranged inside the shell, wherein the upper tube plate and the lower tube plate divide the shell into an upper tube box and a lower tube box at two ends, and a shell-side cylinder in the middle; a plurality of reaction tubes are arranged in the shell-side cylinder, and the two ends of the reaction tubes are respectively arranged on the upper tube plate and the lower tube plate; a reactant inlet is arranged on the lower tube box, and a reactant outlet is arranged on the upper tube box; a first annular channel and a second annular channel are respectively arranged on both sides of the shell-side cylinder close to the upper tube plate and the lower tube plate in the circumferential direction, and a plurality of through holes for molten salt to enter and exit are arranged in the circumferential direction of the shell-side cylinder, so as to form an annular distributor, so as to ensure that the molten salt pumped into the annular distributor can uniformly enter the shell-side cylinder of the reactor from each distributed through hole, so that the reaction tubes at each position can be uniformly heated by the molten salt, thereby improving the reaction efficiency, ensuring the stable quality of the product, and increasing the economic benefit.

Description

Technical Field

[0001] The utility model relates to the technical field of reactors, in particular to a tubular reactor. Background Art

[0002] Tubular reactor is a reactor with special structure, mainly used in the occasions with high reaction temperature and strict requirements on reaction temperature. For tubular reactors with high reaction temperature, molten nitrate (molten salt for short) is mostly used as heating agent at present, and the molten salt is heated by electric heater, and the heated molten salt is sent to the shell cylinder of the reactor by molten salt circulation pump to heat the materials in the reaction tube. In order to keep the reaction temperature in the reactor stable, a large flow molten salt pump is generally used to increase the circulation volume of molten salt.

[0003] In the past, tubular reactors had a pair of connecting pipes at the upper and lower parts of the shell side cylinder as the inlet and outlet of the molten salt. The inlet and outlet positions were staggered 180 degrees from each other. The molten salt circulation pump extracted the molten salt from the molten salt outlet at the lower part of the shell side, sent it to the molten salt heater for heating, and then sent it to the molten salt inlet at the upper part of the shell side, so that the molten salt returned to the shell side cylinder of the reactor to continue heating the materials in the reactor.

[0004] This type of reactor has an obvious disadvantage, that is, after the circulating pump returns the heated molten salt to the shell side of the reactor, because there are many reaction tubes inside the shell, the molten salt cannot be evenly distributed over the entire cross-section. The flow rate of molten salt at each position is different, resulting in uneven heating temperature of the material in the reaction tube, affecting the yield and quality stability of the product and reducing the economic benefits.

[0005] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Utility Model Content

[0006] The utility model provides a tubular reactor, thereby effectively solving the problems in the background technology.

[0007] In order to achieve the above object, the technical solution adopted by the utility model is: a tubular reactor, comprising a shell and an upper tube sheet and a lower tube sheet arranged inside the shell, wherein the upper tube sheet and the lower tube sheet divide the shell into an upper tube box and a lower tube box at two ends, and a shell-side cylinder in the middle;

[0008] A plurality of reaction tubes are arranged in the shell-side cylinder, and two ends of each reaction tube are arranged on the upper tube plate and the lower tube plate respectively;

[0009] The lower tube box is provided with a reactant inlet, and the upper tube box is provided with a reactant outlet;

[0010] The shell-side cylinder is provided with a first annular channel and a second annular channel on both sides of the circumference close to the upper tube plate and the lower tube plate, respectively; the first annular channel is provided with a molten salt inlet, and the second annular channel is provided with a molten salt outlet;

[0011] The shell-side cylinder closed by the first annular channel and the second annular channel is circumferentially provided with a plurality of through holes for the molten salt to enter and exit.

[0012] Furthermore, the first annular channel is eccentrically arranged toward a side close to the molten salt inlet, and the second annular channel is eccentrically arranged toward a side close to the molten salt outlet.

[0013] Furthermore, a herringbone guide plate is provided in the first annular channel near the molten salt inlet.

[0014] Furthermore, the through hole is at least one of square, oval, circular, and polygonal.

[0015] Furthermore, the through hole is rectangular or elliptical, and the length direction of the rectangle or the ellipse is parallel to the axial direction of the shell-side cylinder.

[0016] Furthermore, the areas of the through holes in the circumferential direction of the shell-side cylinder gradually expand from the molten salt inlet or the molten salt outlet to the opposite side.

[0017] Furthermore, the widths of the through holes in the circumferential direction of the shell-side cylinder gradually expand from the molten salt inlet or the molten salt outlet to the opposite side.

[0018] Furthermore, the density of the through holes in the circumferential direction of the shell-side cylinder gradually increases from the molten salt inlet or the molten salt outlet to the opposite side.

[0019] Furthermore, the inner wall of the through hole in the circumferential direction of the shell-side cylinder is a straight hole along the flow direction of the molten salt.

[0020] Furthermore, the inner walls of the through holes in the circumferential direction of the shell-side cylinder are diffusely arranged along the flow direction of the molten salt.

[0021] The beneficial effects of the utility model are as follows: the utility model respectively arranges a first annular channel and a second annular channel on both sides of the shell-side cylinder close to the upper tube plate and the lower tube plate in the circumferential direction of the shell-side cylinder, and arranges a plurality of through holes for the molten salt to enter and exit in the circumferential direction of the shell-side cylinder to form an annular distributor, thereby ensuring that the molten salt circulated and pumped into the annular distributor can evenly enter the shell-side cylinder of the reactor from each distributed through hole, so that the reaction tubes in each part can be evenly heated by the molten salt, thereby improving the reaction efficiency, ensuring the stable quality of the product, and increasing the economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is a schematic diagram of the structure of a tubular reactor (half of the shell is removed);

[0024] Figure 2 For Figure 1 A partial enlarged view of the middle A;

[0025] Figure 3 is a cross-sectional view of a tubular reactor;

[0026] Figure 4 A schematic diagram of the structure in which the first annular channel, the second annular channel and the center of the shell cylinder are eccentrically arranged;

[0027] Figure 5 It is a structural schematic diagram of a herringbone guide plate arranged in the first annular channel;

[0028] Figure 6 A structural schematic diagram of a specific implementation of through-hole arrangement;

[0029] Figure 7 A schematic structural diagram of another specific implementation of through-hole arrangement;

[0030] Figure 8 A structural schematic diagram of a specific implementation of the inner wall of the through hole;

[0031] Fig. 9 It is a structural schematic diagram of another specific implementation of the inner wall of the through hole.

[0032] Figure numerals: 1, shell; 11, upper tube box; 111, reactant outlet; 12, shell-side cylinder; 121, through hole; 13, lower tube box; 131, reactant inlet; 2, upper tube sheet; 3, lower tube sheet; 4, reaction tube; 5, first annular channel; 51, molten salt inlet; 52, herringbone guide plate; 6, second annular channel; 61, molten salt outlet; 7, support. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0034] In the description of the present invention, it should be noted that the directions or positional relationships indicated by “center”, “up”, “down”, “left”, “right”, “vertical”, “horizontal”, “inside” and “outside”, etc., are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] like Figures 1 to 9 As shown: a tubular reactor comprises a shell 1 and an upper tube sheet 2 and a lower tube sheet 3 arranged inside the shell 1, wherein the upper tube sheet 2 and the lower tube sheet 3 divide the shell 1 into an upper tube box 11 and a lower tube box 13 at two ends, and a shell-side cylinder 12 in the middle;

[0037] A plurality of reaction tubes 4 are arranged in the shell-side cylinder 12, and both ends of each reaction tube 4 are arranged on the upper tube sheet 2 and the lower tube sheet 3 respectively;

[0038] The lower tube box 13 is provided with a reactant inlet 131, and the upper tube box 11 is provided with a reactant outlet 111; specifically, the flow path of the reactant is that the reactant enters from the reactant inlet 131, passes through the lower tube box 13, the reaction tube 4, and the upper tube box 11 in sequence, and is discharged from the reactant outlet 11 to the next process or storage tank after the reaction is completed;

[0039] The shell side cylinder 12 is provided with a first annular channel 5 and a second annular channel 6 on both sides close to the upper tube sheet 2 and the lower tube sheet 3 in the circumferential direction, respectively. The first annular channel 5 is provided with a molten salt inlet 51, and the second annular channel 6 is provided with a molten salt outlet 61;

[0040] The shell-side cylinder 12 enclosed by the first annular channel 5 and the second annular channel 6 is provided with a plurality of through holes 121 for the molten salt to enter and exit in the circumferential direction; the number of the through holes 121 is determined according to the actual diameter size of the shell-side cylinder 12 on site;

[0041] The flow path of the molten salt is as follows: the molten salt enters from the molten salt inlet 51, passes through the first annular channel 5, the through hole 121 of the first annular channel 5, the shell-side cylinder 12, the through hole 121 of the second annular channel 6, and the second annular channel 6 in sequence, and is discharged from the molten salt outlet 61. The heated molten salt is then sent to the reactor by a circulation pump, and this cycle is repeated to provide a suitable reaction temperature inside the reactor.

[0042] like Figures 1 to 3 As shown, a first annular channel 5 and a second annular channel 6 are respectively provided on both sides of the shell-side cylinder 12 near the upper tube sheet 2 and the lower tube sheet 3 in the circumferential direction, and a plurality of through holes 121 for the molten salt to enter and exit are provided in the circumferential direction of the shell-side cylinder 12 to form an annular distributor, so as to ensure that the molten salt circulated and pumped into the annular distributor can evenly enter the shell-side cylinder 12 of the reactor from each distributed through hole 121, so that the reaction tubes 4 at each position can be evenly heated by the molten salt, thereby improving the reaction efficiency, ensuring the stable quality of the product, and increasing the economic benefits.

[0043] Since the annular distributor is arranged outside the shell-side cylinder 12, it can be improved on the basis of the existing tubular reactor by adding the first annular channel 5 and the second annular channel 6, and then processing a plurality of through holes 121 for the entry and exit of molten salt on the circumference of the shell-side cylinder 12. There is no need to make major changes to the reactor structure, and it has good feasibility and ease of implementation, which is convenient for upgrading and modifying existing production equipment and reducing costs.

[0044] The cross-sections of the first annular channel 5 and the second annular channel 6 are square, semicircular, polygonal or other shapes, which are all within the protection scope of the present application.

[0045] A support 7 for supporting the reactor is also provided at the bottom of the lower tube box 13 to keep the reactor stable.

[0046] As a preferred embodiment of the above, Figure 4 As shown, the first annular channel 5 and the second annular channel 6 are eccentrically arranged with respect to the center of the shell cylinder 12, and the first annular channel 5 is eccentrically arranged to the side close to the molten salt inlet 51, and the second annular channel 6 is eccentrically arranged to the side close to the molten salt outlet 61. Specifically, since the molten salt flow rate at the molten salt inlet 51 and the molten salt outlet 61 is large, the eccentric arrangement can make the width of the channel on one side of the molten salt inlet 51 and the molten salt outlet 61 wider, the flow rate of the molten salt on the opposite side is small, and the width of the channel opposite to the molten salt inlet 51 and the molten salt outlet 61 is smaller, thereby ensuring that the circumferential flow rate of the molten salt in the first annular channel 5 and the second annular channel 6 is relatively stable, which helps to achieve uniform molten salt distribution and uniform heating effect inside the entire shell, thereby improving the heating uniformity of the reactor.

[0047] In this embodiment, reference Figure 5A herringbone guide plate 52 is provided in the first annular channel 5 near the molten salt inlet 51. On the one hand, the herringbone guide plate 52 can effectively guide the flow direction of the molten salt, reduce the turbulence and eddy current of the molten salt in the annular channel, and reduce the flow resistance; on the other hand, due to the effect of the herringbone guide plate 52, the molten salt can be divided into two paths and enter the annular channel evenly from both sides, ensuring that the molten salt flow on both sides is consistent, thereby improving the heating uniformity and reaction efficiency of the material in the reactor.

[0048] Among them, the through hole 121 is square, oval, circular, polygonal, or at least one of them. Specifically, the through holes 121 of different shapes can accurately control the flow and distribution of the molten salt according to specific needs. Different choices can be made according to the materials introduced on site. They can all be square holes or oval holes, or holes of several shapes can be combined with each other, all of which are within the protection scope of the present application.

[0049] As a preferred embodiment of the above embodiment, the through hole 121 is rectangular or elliptical, and the length direction of the rectangle or ellipse is parallel to the axial direction of the shell cylinder 12. The rectangular through hole 121 and the elliptical through hole 121 are used to increase the flow rate of the single through hole 121 of the molten salt inlet 51 and the molten salt outlet 61, so as to increase the flow rate of the molten salt and ensure that the molten salt can quickly and evenly enter the interior of the shell, improve the heating efficiency, and thus improve the reaction efficiency; the rectangular through hole 121 has a simple processing technology and reduces costs; the elliptical through hole 121 can reduce turbulence and pressure loss during fluid flow, improve the flow efficiency and heat conduction efficiency of the molten salt, and ensure the heating uniformity in the reactor.

[0050] As a specific implementation method of the arrangement of the through holes 121, the areas of the plurality of through holes 121 on the circumferential direction of the shell-side cylinder 12 gradually expand from the molten salt inlet 51 or the molten salt outlet 61 to the opposite side. Since the molten salt flow rate near the molten salt inlet 51 and the molten salt outlet 61 is short and the resistance is small, while the molten salt flow rate is long and the resistance is large on the side far from the molten salt inlet 51 and the molten salt outlet 61, by adjusting the area of ​​the through holes 121, the area of ​​the through holes 121 near the molten salt inlet 51 and the outlet is smaller, and the area of ​​the through holes 121 far from the molten salt inlet 51 and the outlet is larger, it can be ensured that the flow distribution of the molten salt is uniform in the entire circumferential direction, avoiding the problem of local flow unevenness caused by resistance differences.

[0051] As a preferred embodiment of the above, Figure 6As shown, the widths of the plurality of through holes 121 on the circumference of the shell-side cylinder 12 gradually expand from the molten salt inlet 51 or the molten salt outlet 61 to the opposite side. Expanding the width of the through holes 121 can increase the effective area for the circulation of the molten salt, so that the through holes 121 near the molten salt inlet 51 and the outlet are narrower, while the through holes 121 away from the inlet and the outlet are wider, which can compensate for the increased resistance caused by the long flow path, thereby keeping the flow of each through hole 121 consistent. The uniform molten salt flow distribution can ensure that all reaction tubes 4 can receive the same heating, thereby improving the heating uniformity of the material in the entire reactor, avoiding local overheating or overcooling, and improving the reaction efficiency and the stability of product quality.

[0052] like Figure 7 As shown, as another specific implementation of the arrangement of the through holes 121, the density of the plurality of through holes 121 in the circumferential direction of the shell-side cylinder 12 gradually increases from the molten salt inlet 51 or the molten salt outlet 61 to the opposite side, the area of ​​a single through hole 121 is fixed, and the gap between adjacent through holes 121 gradually decreases, that is, the density of the through holes 121 gradually increases from the molten salt inlet 51 or the molten salt outlet 61 to the opposite side, which can also compensate for the increase in resistance caused by the longer flow path, ensuring that the molten salt flow rate in the circumferential direction of the entire shell-side cylinder 12 is evenly distributed, thereby avoiding the problem of excessive or insufficient local flow.

[0053] refer to Figure 8 As a specific implementation of the inner wall of the through hole 121, the inner wall of the through hole 121 in the circumferential direction of the shell-side cylinder 12 is a straight hole along the flow direction of the molten salt. Specifically, the straight hole is relatively easy to process and manufacture, which reduces the manufacturing difficulty and cost and improves the production efficiency and product consistency.

[0054] refer to Fig. 9 As another specific implementation of the inner wall of the through hole 121, the inner wall of the through hole 121 in the circumferential direction of the shell-side cylinder 12 is diffusely arranged along the flow direction of the molten salt. Specifically, on the one hand, the molten salt enters the shell-side cylinder 12 in a divergent manner along the side wall of the through hole 121, presenting a relatively uniform flow state, avoiding the velocity gradient and flow unevenness that may occur during the entry of the molten salt, and ensuring the uniformity of the molten salt flow in the entire shell-side cylinder 12; on the other hand, the diffusion arrangement of the inner wall of the through hole 121 can promote the molten salt to be better mixed and evenly distributed when entering the shell-side cylinder 12 through the through hole 121, which helps to improve the heat conduction efficiency between the molten salt and the reaction tube 4, and improve the overall thermal efficiency of the reactor.

[0055] Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the description are only for explaining the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which are within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A tubular reactor, characterized in that: It comprises a shell and an upper tube sheet and a lower tube sheet arranged inside the shell, wherein the upper tube sheet and the lower tube sheet divide the shell into an upper tube box and a lower tube box at two ends, and a shell-side cylinder in the middle; A plurality of reaction tubes are arranged in the shell-side cylinder, and two ends of each reaction tube are arranged on the upper tube plate and the lower tube plate respectively; The lower tube box is provided with a reactant inlet, and the upper tube box is provided with a reactant outlet; The shell-side cylinder is provided with a first annular channel and a second annular channel on both sides of the circumference close to the upper tube plate and the lower tube plate, respectively; the first annular channel is provided with a molten salt inlet, and the second annular channel is provided with a molten salt outlet; The shell-side cylinder closed by the first annular channel and the second annular channel is circumferentially provided with a plurality of through holes for the molten salt to enter and exit.

2. The tubular reactor according to claim 1, characterized in that The first annular channel and the second annular channel are eccentrically arranged with respect to the center of the shell-side cylinder, and the first annular channel is eccentrically arranged toward the side close to the molten salt inlet, and the second annular channel is eccentrically arranged toward the side close to the molten salt outlet.

3. The tubular reactor according to claim 1, characterized in that A herringbone guide plate is provided in the first annular channel near the molten salt inlet.

4. The tubular reactor according to claim 1, characterized in that The through hole is in at least one of an elliptical shape, a circular shape, and a polygonal shape.

5. The tubular reactor according to claim 4, characterized in that The through hole is rectangular or elliptical, and the length direction of the rectangle or the ellipse is parallel to the axial direction of the shell-side cylinder.

6. The tubular reactor according to claim 1, characterized in that The areas of the through holes in the circumferential direction of the shell-side cylinder gradually expand from the molten salt inlet or the molten salt outlet to the opposite side.

7. The tubular reactor according to claim 5, characterized in that The widths of the through holes in the circumferential direction of the shell-side cylinder gradually expand from the molten salt inlet or the molten salt outlet to the opposite side.

8. The tubular reactor according to claim 1, characterized in that The density of the through holes in the circumferential direction of the shell-side cylinder gradually increases from the molten salt inlet or the molten salt outlet to the opposite side.

9. The tubular reactor according to claim 1, characterized in that The inner wall of the through hole in the circumferential direction of the shell-side cylinder is a straight hole along the flow direction of the molten salt.

10. The tubular reactor according to claim 1, characterized in that The inner walls of the through holes in the circumferential direction of the shell-side cylinder are diffusely arranged along the flow direction of the molten salt.

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