CN211274584U

CN211274584U - Fixed bed reactor

Info

Publication number: CN211274584U
Application number: CN201921923485.6U
Authority: CN
Inventors: 陈延坤; 王飞
Original assignee: Shandong Nerve Pharmaceutical Fluid System Co ltd
Current assignee: Shandong Nerve Pharmaceutical Fluid System Co ltd
Priority date: 2018-11-15
Filing date: 2019-11-08
Publication date: 2020-08-18
Anticipated expiration: 2029-11-08

Abstract

The utility model belongs to the technical field of chemical industry pharmaceutical equipment technique and specifically relates to a fixed bed reactor, a serial communication port, include: the casing, be provided with the shell side entry and the shell side export that are linked together rather than the inner chamber on the casing, the upper and lower both ends of casing all are connected with tube sheet and baffle box, the inside of casing is provided with the reaction nest of tubes, the reaction nest of tubes includes many reaction tubes, and the upper and lower both ends of every reaction tube all pass and fixed connection on the tube sheet, and all reaction tubes pass through baffle box and establish ties the intercommunication one by one in proper order. It compares the reaction flow under the condition of traditional reactor looks isovolumetric and promotes greatly on the one hand, makes the reactant obtain high reynolds number under the low velocity of flow condition on the one hand, improves the torrent effect greatly, still can incessantly mix in the reaction of constantly flowing, but the state of each reaction stage of real-time detection on the one hand makes the reactor can install the catalyst and catalyzes the reactant on the one hand, thereby conveniently change the catalyst simultaneously and adapt to different reactions.

Description

Fixed bed reactor

Technical Field

The utility model belongs to the technical field of chemical industry pharmaceutical equipment technique and specifically relates to a fixed bed reactor.

Background

Reactor equipment commonly used in the technical field of chemical pharmacy comprises a tubular reactor, a kettle reactor and the like, wherein the kettle reactor is usually provided with a stirring device in a reaction kettle for mixing liquid-phase reactants, and the product has low purity, low reaction conversion rate and serious energy consumption and pollution. Because the chemical pharmaceutical field has high requirements on the purity and the like of products, the reactor equipment commonly used is a continuous flow tubular reactor.

The concentration and the reaction rate of chemical reactants in the tubular reactor change along with the length of the tube, so the tubular reactor needs to meet the length of the tube required by the chemical reaction, and the existing straight tube reactor or U-shaped tube reactor needs to have longer tube length, so the volume of the reactor is too large. In addition, the flowing state of reactants in the reaction tube can directly influence the heat transfer rate and the uninterrupted mixing effect of the reaction, and the traditional straight tube reactor has poor turbulent effect of reaction materials and low Reynolds coefficient, and is not beneficial to heat transfer and the uninterrupted mixing effect. Meanwhile, the catalyst is inconvenient to place and replace in the conventional tubular reactor, thereby catalyzing the reaction.

SUMMERY OF THE UTILITY MODEL

The utility model aims at solving the above-mentioned problem, the utility model provides a fixed bed reactor, it compares the reaction flow under the condition of the same volume of traditional reactor and promotes greatly on the one hand, make the reactant obtain high reynolds number under the low velocity of flow condition on the one hand, improve the torrent effect greatly, still can incessantly mix in the reaction of constantly flowing, but the state of each reaction stage of real-time detection on the one hand, installation that on the one hand can be convenient and dismantlement solid catalysis thing are in order to adapt to different reactions, make the installation assembly simplify on the one hand again, the technical scheme of its adoption as follows:

a fixed bed reactor, comprising: the casing, be provided with shell side entry and shell side export that is linked together rather than the inner chamber on the casing, the upper and lower both ends of casing all are connected with tube sheet and baffle box, the baffle groove of a plurality of phase separations has been seted up on the baffle box, a plurality of looks discrete baffling passageway are constituteed jointly to the baffle groove of tube sheet and baffle box, the inside of casing is provided with the reaction tube group, the reaction tube group includes many reaction tubes, the reaction tube has set gradually the multilayer from inside to outside, and the upper and lower both ends of every reaction tube all pass and fixed connection on the tube sheet, and adjacent reaction tube is through establishing ties the intercommunication one by one in proper order with their corresponding baffling passageway, be provided with reactant entry and reactant export on the baffle box, be provided with the solid catalysis thing in the baffle groove.

On the basis of the above technical solution, the solid catalytic material occupies part or all of the cross section of the baffle tank.

On the basis of the technical scheme, the solid catalytic substance is provided with a through hole, reactant flows pass through the solid catalytic substance through the through hole, and the through hole is a large hole or consists of a plurality of small holes.

On the basis of the technical scheme, the solid catalytic substance is net-shaped.

On the basis of the technical scheme, the diversion groove is a straight groove, a wedge-shaped groove or an arc-shaped groove.

On the basis of the technical scheme, the tube plate or/and the diversion groove are/is provided with an installation groove for accommodating the solid catalytic substance, and the solid catalytic substance is installed in the installation groove.

On the basis of the technical scheme, the tube plates are fixedly connected to the upper end and the lower end of the shell, the reaction tubes penetrate through the tube plates and are fixedly connected with the tube plates, the tail ends of the reaction tubes are welded with the tube plates through welding points, and the tube plates are tightly attached to the baffle box through flanges and bolts.

On the basis of the technical scheme, the arrangement of the deflection grooves on the upper deflection pipe box and the lower deflection pipe box and the arrangement of the through holes on the upper tube plate and the lower tube plate ensure that the top ends and the bottom ends of the reaction tubes of each layer are arranged according to the following modes:

from outside to inside: the top ends of all the first layer of reaction tubes, namely the outermost layer of reaction tubes, are arranged to form a first upper circle, the top ends of all the second layer of reaction tubes are arranged to form a second upper circle, the second upper circle is concentric with the first upper circle, and the diameter of the second upper circle is smaller than that of the first upper circle, and so on until the last layer of reaction tubes, namely the innermost layer of reaction tubes; from outside to inside: the bottom ends of all the first layer of reaction tubes, namely the outermost layer of reaction tubes, are arranged to form a first lower circle, the bottom ends of all the second layer of reaction tubes are arranged to form a second lower circle, the second lower circle is concentric with the first lower circle, and the diameter of the second lower circle is smaller than that of the first lower circle, and so on until the last layer of reaction tubes, namely the innermost layer of reaction tubes; the upper circular circle center and the lower circular circle center are both positioned on the axis of the shell, and the included angle between the vertical connecting line from the top end of each reaction tube to the axis of the shell and the vertical connecting line from the bottom end of each reaction tube to the axis of the shell in the same layer is equal.

All the straight line connecting lines from the top ends of the reaction tubes to the bottom ends of the reaction tubes are parallel to the axis of the shell.

On the basis of the technical scheme, when the number of the reaction tubes is even, N reaction tubes are arranged, the reactant inlet and the reactant outlet are positioned on the same baffle box, the baffle grooves on the baffle box with the reactant inlet are (N/2) -1, and the baffle grooves on the other baffle box are N/2; when the number of the reaction tubes is odd, the reaction tubes are N, the reactant inlet and the reactant outlet are positioned on different baffle boxes, and the baffle grooves on the upper baffle box and the lower baffle box are (N-1)/2.

On the basis of the technical scheme, the reaction tube is a straight tube or a spiral winding tube.

On the basis of the technical scheme, one or more online detection instruments are detachably arranged on the baffle box and are communicated with the baffle groove.

On the basis of the technical scheme, 2 spiral lines with opposite rotation directions and consistent rotation lifting angles are pressed along the outer wall of the reaction tube, so that the inner wall of the reaction tube is inwards protruded to form spiral protrusions corresponding to the two spiral lines.

The utility model has the advantages of as follows: compare reaction flow under the condition of traditional reactor looks isovolumetric and promote greatly on the one hand, make the reactant obtain high reynolds number under the low velocity of flow condition on the one hand, improve the torrent effect greatly, still can incessant the mixture in the reaction of constantly flowing, but the state of each reaction stage of real-time detection on the one hand makes the installation assembly simplify again on the one hand, makes the reactor can install the catalyst on the one hand and catalyzes the reactant, thereby conveniently change the catalyst simultaneously and adapt to different reactions.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawing in the following description is only an embodiment of the invention, and that for a person skilled in the art, other embodiments can be derived from the drawing provided without inventive effort.

FIG. 1: is a structural schematic diagram with a local section (the reaction tube is a spiral winding tube) of the utility model;

FIG. 2: is a structural schematic diagram of the reaction tube group of the utility model;

FIG. 3: is a structural schematic diagram of the reaction tube group of the utility model after being partially cut;

FIG. 4: is a bottom view of an example of the upper baffle box of the present invention;

FIG. 5: is a top view of an example of the lower baffle box of the present invention;

FIG. 6: is a schematic structural diagram of the lower sealing gasket of the utility model;

FIG. 7: the utility model discloses a partial section structure schematic diagram of a tube plate;

FIG. 8: the partial section structure schematic diagram of the reaction tube of the utility model;

FIG. 9: the utility model discloses a partial section side view structure schematic diagram of an example of a solid catalytic substance;

FIG. 10: the utility model discloses a partial section main view structure schematic diagram of an example of the solid catalytic substance;

FIG. 11: the utility model discloses a partial section main view structure schematic diagram of an example of the solid catalytic substance;

FIG. 12: is a bottom view of an example of the upper baffle box of the present invention;

FIG. 13: the utility model discloses a partial section overlooking structure schematic diagram of an example of the solid catalytic substance;

FIG. 14: the utility model discloses a three-dimensional structure schematic diagram of an example of the solid catalytic substance;

FIG. 15: is a structural schematic diagram with a local section (the reaction tube is a straight tube) of the utility model;

Detailed Description

The invention will be further described with reference to the following figures and examples:

reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1

As shown in fig. 1 to 15, the fixed bed reactor of the present embodiment includes: the shell body 1, be provided with shell side entry 10 and shell side export 11 that are linked together rather than the inner chamber on the shell body 1, the shell side of shell body 1 is used for circulating heat transfer medium, makes the reactant in the reaction tube 20 tube side keep suitable reaction temperature, the upper and lower both ends of shell body 1 all are connected with tube sheet 3 and baffling pipe case 4, the inside of shell body is provided with reaction nest of tubes 2, reaction nest of tubes 2 includes many reaction tubes 20, and the upper and lower both ends of every reaction tube all pass and fixed connection on tube sheet 3, and all reaction tubes 20 are through baffling pipe case 4 and are established ties the intercommunication one by one in proper order.

As shown in fig. 4 and 5, the baffle box 4 is provided with a plurality of separated baffle slots 40, the tube plate 3 and the baffle slots 40 of the baffle box together form a plurality of separated baffle channels, the reaction tubes 20 adjacent to each other in the medium flow sequence are sequentially communicated in series one by one through the corresponding baffle channels, and the baffle box 4 is provided with a reactant inlet 41 and a reactant outlet 42. That is, when the reactant inlet 41 is provided on the lower baffle box 4, the flow sequence of the reactant in the reaction tube group 2 is that the reactant enters the bottom end of the first reaction tube from the reactant inlet 41 on the baffle box 4, passes through the first reaction tube, enters the deflection groove 40 of the upper baffle box 4 (the deflection groove corresponds to and communicates with the top end of the first reaction tube and the top end of the second reaction tube), then enters the top end of the second reaction tube, passes through the second reaction tube, enters the deflection groove 40 of the lower baffle box 4 (the deflection groove corresponds to and communicates the bottom end of the second reaction tube and the bottom end of the third reaction tube), then enters the bottom end of the third reaction tube, passes through the third reaction tube, and enters the deflection groove 40 of the upper baffle box 4 from the top end of the third reaction tube (the deflection groove corresponds to and communicates with the top end of the third reaction tube and the fourth reaction tube) Correspond to each other and connect them to each other) and then enter from the top end of the fourth reaction tube, and so forth until the reactant flows out from the reactant outlet 42. It should be noted that the first and second in this paragraph correspond to the flow sequence of the reactants, and the first reaction tube is the first reaction tube through which the reactants first flow. The utility model discloses a baffle pipe case for continuous flow reactor is when using, and adjacent reaction tube is linked together through the baffling groove on the transmission direction of medium, and adjacent reaction tube need not pass through elbow or U-shaped union coupling, also needn't receive the radial restriction of return bend, and the reaction tube interval is less, and the reactor volume is less, and the reaction procedure is long.

Preferably, the reaction tube group 2 is composed of a plurality of reaction tubes 20 arranged in sequence from inside to outside, and the reaction tubes 20 are spirally wound tubes having a certain spiral angle, so that the reaction stroke can be further increased with the same volume.

As shown in fig. 1, it is preferable that one or more in-line meters 43 are detachably provided on the baffle box, and the in-line meters 43 communicate with the baffle 40. Thereby online detection instrument optional temperature detection instrument, pressure detection instrument, pH value detection instrument etc. are used for detecting the real-time temperature, pressure and the pH value condition of reactant in the reactor as required, and preferably in addition, can be provided with a plurality of online detection instrument interfaces on the baffle pipe case, thereby online detection instrument can detect the state of different flow length (behind the different number of reaction tubes) reactant reaction through connecing different interfaces and then being linked together with different baffle groove 40.

As shown in fig. 7, preferably, the tube plates 3 are fixedly connected to the upper and lower ends of the shell 1, the reaction tubes 20 pass through the tube plates 3 and are fixedly connected to the tube plates 3, and the tube plates 3 are tightly attached to the baffle boxes 4 by flanges and bolts. Further, the ends of the reaction tubes 20 are welded to the tube plate 3 by the welding points 201, so that the reaction tubes 20 are prevented from being welded through during welding and the firmness and tightness of the welding can be ensured.

Further, in order to ensure the connection tightness between the tube plate 3 and the baffle box 4, prevent the leakage of the medium in the baffle groove, and simultaneously prevent the medium from entering and flowing out of the baffle groove, a sheet type sealing gasket 6 is arranged between the baffle box and the tube plate, and the sheet type sealing gasket is provided with baffle holes 60 corresponding to the two tail ends of each baffle groove, so as to ensure the sealing of the reactant in the flow process.

Because the reaction tube has many spiral winding tubes simultaneously, when installing, it will combine with the tube sheet 3 and correspond to the baffling groove 40 of the baffling tube box 4, if there is not certain arrangement rule, it will be difficult or even impossible to realize when installing, still cause installer's confusion easily, increased man-hour of installation, installation error rate, so for the convenience of installing spiral winding tube, it is preferred, the laying of baffling groove 40 on upper and lower baffling tube box 4 and the laying of through-mounting hole on upper and lower tube sheet 3 make the top and bottom of each layer of reaction tube 20 arrange according to the following mode:

from outside to inside: the top ends of all the first layer of reaction tubes 20, namely the outermost layer of reaction tubes 20, are arranged to form a first upper circle, the top ends of all the second layer of reaction tubes 20 are arranged to form a second upper circle, the second upper circle is concentric with and the diameter of the first upper circle is smaller than that of the first upper circle, and so on until the last layer of reaction tubes, namely the innermost layer of reaction tubes; from outside to inside: the bottom ends of all the first layer of reaction tubes 20, namely the outermost layer of reaction tubes 20, are arranged to form a first lower circle, the bottom ends of all the second layer of reaction tubes 20 are arranged to form a second lower circle, the second lower circle is concentric with the first lower circle, and the diameter of the second lower circle is smaller than that of the first lower circle, and so on until the last layer of reaction tubes, namely the innermost layer of reaction tubes; the upper circular circle center and the lower circular circle center are both positioned on the axis of the shell 1, and the included angle between the vertical connecting line from the top end of each reaction tube belonging to the same layer to the axis of the shell 1 and the vertical connecting line from the bottom end of the same reaction tube to the axis of the shell 1 is equal. Furthermore, the straight line connecting the top ends of all the reaction tubes to the bottom ends thereof (which is the connecting line of the top end and the bottom end of the same reaction tube) is parallel to the axis of the shell 1.

When the number of the reaction tubes 20 is an even number, it is assumed that the number of the reaction tubes is N, the reactant inlet 41 and the reactant outlet 42 are located on the same baffle box, the number of the baffle slots 40 on the baffle box having the reactant inlet 41 is (N/2) -1, and the number of the baffle slots 40 on the other baffle box is N/2; when the number of the reaction tubes 20 is odd, it is assumed that the number is N, the reactant inlet 41 and the reactant outlet 42 are located on different baffle boxes, and the baffle slots 40 on the upper and lower baffle boxes are (N-1)/2.

Preferably, the reaction tube 20 is a straight tube or a spirally wound tube.

As shown in fig. 8, it is preferable that 2 spiral lines 20a with opposite rotation directions and consistent rotation elevation angles are pressed along the outer wall of the reaction tube 20, so that the inner wall of the reaction tube is protruded inwards to form two spiral protrusions corresponding to the spiral lines. So reaction material can form great vortex when wherein flowing, and the reactant forms heliciform tangential motion along spiral arch, further improves the reynolds number that reaction material flows, improves the torrent effect greatly, improves reaction material's heat transfer and mixed effect.

The solid catalyst 44 may be fixed in the baffle 40 in the following ways:

the first fixing mode: as shown in fig. 7, the solid catalyst 44 is disposed in the cavity formed by the tube plate 3 and the diversion groove 40, and the solid catalyst 44 is in interference fit with the cavity.

And (2) fixing form II: as shown in fig. 9 and 12, a first mounting groove 46 is formed in the inner wall of the diversion trench 40, and a part of the solid catalyst 44 is inserted into the first mounting groove 46 and fixed in position relative to the diversion trench 40. The first mounting groove 46 may be formed at the bottom of the bending groove 40 or at the side wall of the first mounting groove 46, or the first mounting groove 46 may be formed at both the bottom and the side wall.

The fixed form is three: as shown in fig. 9, the tube plate 3 is formed with a second fitting groove 47 at the corresponding position of the baffle groove 40, and a part of the solid catalyst 44 is inserted into the second fitting groove 47 to be fixed in position relative to the baffle groove 40 and the tube plate 3.

The fixed form is four: as shown in fig. 13, the diversion trench 40 may be a wedge-shaped trench and the solid catalyst 44 may be a wedge-shaped block. In the diversion trench 40 of fig. 13, the flow direction of the reactants is from left to right, the solid catalyst 44 is restricted from moving to the right due to the decreasing cross-sectional area of the diversion trench 40 to the right, and the solid catalyst 44 is restricted from moving to the left due to the flow direction of the reactants.

The above fixing forms may be used alone, or a plurality of fixing forms may be combined to be used simultaneously, and fig. 9 is an example of using a plurality of fixing forms simultaneously.

The catalytic passage of the solid catalyst 44 in the baffle 40 may take the form of:

the first channel form: as shown in fig. 7, 11, 13 and 14, the channels in the solid catalyst 44 may be a plurality of relatively small diameter through holes 45, and the reactants pass through the plurality of through holes 45 to perform catalytic reaction. Wherein, the adjacent through holes 45 can be connected by the connecting channel between the adjacent through holes 45.

Channel type two: as shown in fig. 9, the channel in the solid catalyst 44 may be a single through-hole 45 with a relatively large diameter.

The channel form III: as shown in fig. 10, there is a gap between the solid catalyst 44 and the baffle 40, and the gap can be used as a channel through which the reactant flows, such as the gap between the top of the solid catalyst 44 and the baffle 40 in fig. 10. The gap may also be provided on both sides of the solid catalyst 44.

Channel type four: as shown in fig. 10, there is a gap between the solid catalyst 44 and the tube plate 3, and the gap can be used as a channel through which the reactant flows, such as the gap between the bottom of the solid catalyst 44 and the tube plate 3 in fig. 10.

Channel type five: the solid catalyst 44 is in the form of a net having a plurality of meshes.

The above channel forms may be used alone or in combination of a plurality of channel forms to be used simultaneously, and fig. 10 and 11 are two examples of using a plurality of fixing forms simultaneously.

The solid catalyst 44 may use any combination between the above various immobilization forms and channel forms.

The solid catalyst 44 may be a bulk metal catalyst (e.g., electrolytic silver, fused iron, platinum gauze, etc.), a supported metal catalyst (e.g., Ni/Al)₂O₃Hydrogenation catalyst), alloy catalyst (active component is composed of two or more metal atoms, such as Ni-Cu alloy hydrogenation catalyst,LaNi₅hydrogenation catalysts, etc.), and the like.

The present invention has been described above by way of example, but the present invention is not limited to the above-mentioned embodiments, and any modification or variation based on the present invention is within the scope of the present invention.

Claims

1. A fixed bed reactor, comprising: casing (1), be provided with shell side entry (10) and shell side export (11) that are linked together rather than the inner chamber on casing (1), the upper and lower both ends of casing (1) all are connected with tube sheet (3) and baffle box (4), baffle groove (40) of a plurality of phase separations have been seted up on baffle box (4), a plurality of phase separation's baffling passageway is constituteed jointly in tube sheet (3) and baffle box's baffling groove (40), the inside of casing is provided with reaction tube group (2), reaction tube group (2) include many reaction tubes (20), reaction tube (20) have set gradually the multilayer from inside to outside, and the upper and lower both ends of every reaction tube all pass and fixed connection on tube sheet (3), and adjacent reaction tube (20) are through establishing ties the intercommunication one by one in proper order with their corresponding baffling passageway one by one, baffle box (4) are last to be provided with reactant entry (41) and reactant export (42), a solid catalytic material (44) is arranged in the diversion groove (40);

a first mounting groove (46) is formed on the inner wall of the diversion groove (40), and a part of the solid catalytic substance (44) is inserted into the first mounting groove (46) and is fixed relative to the diversion groove (40). The first mounting groove (46) can be arranged at the bottom of the bending groove (40) or at the side wall of the first mounting groove (46), and the first mounting groove (46) can also be arranged at the bottom and the side wall of the bending groove.

2. A fixed bed reactor according to claim 1, characterized in that the solid catalytic material (44) occupies part or all of the cross-section of the baffled channel (40).

3. A fixed bed reactor as claimed in claim 2, wherein said solid catalyst (44) is provided with through holes (45), the reactant flows through the solid catalyst (44) via the through holes (45), and said through holes (45) are a large hole or are composed of a plurality of small holes.

4. A fixed bed reactor as claimed in claim 2, wherein said solid catalytic material (44) is in the form of a mesh.

5. A fixed bed reactor as claimed in claim 2, wherein said deflection chute (40) is a straight, wedge or arc shaped chute.

6. A fixed bed reactor in accordance with claim 2, characterized in that the tube plate (3) and/or the baffle tank (40) is provided with an installation slot for accommodating the solid catalyst (44), and the solid catalyst (44) is installed in the installation slot.

7. A fixed bed reactor as set forth in claim 1 wherein: the solid catalyst bodies (44) are arranged in the baffle grooves (40) of the upper baffle box (4) and/or in the baffle grooves (40) of the lower baffle box (4).

8. A fixed bed reactor as set forth in claim 1 wherein: the arrangement of the baffle grooves (40) on the upper baffle box (4) and the lower baffle box (4) and the arrangement of the through holes on the upper tube plate (3) and the lower tube plate (3) lead the top ends and the bottom ends of the reaction tubes (20) of each layer to be arranged according to the following modes:

from outside to inside: the top ends of all the first layer of reaction tubes (20), namely the outermost layer of reaction tubes (20), are arranged to form a first upper circle, the top ends of all the second layer of reaction tubes (20) are arranged to form a second upper circle, the second upper circle is concentric with the first upper circle, the diameter of the second upper circle is smaller than that of the first upper circle, and the rest is done until the last layer of reaction tubes, namely the innermost layer of reaction tubes; from outside to inside: the bottom ends of all the first layer of reaction tubes (20), namely the outermost layer of reaction tubes (20), are arranged to form a first lower circle, the bottom ends of all the second layer of reaction tubes (20) are arranged to form a second lower circle, the second lower circle is concentric with the first lower circle, the diameter of the second lower circle is smaller than that of the first lower circle, and the rest is done until the last layer of reaction tubes, namely the innermost layer of reaction tubes; the upper circular circle center and the lower circular circle center are both positioned on the axis of the shell (1), and the included angle formed by the vertical connecting line from the top end of each reaction tube to the axis of the shell (1) and the vertical connecting line from the bottom end of each reaction tube to the axis of the shell (1) in the same layer is equal.

9. A fixed bed reactor as set forth in claim 1 wherein: when the number of the reaction tubes (20) is even, N reaction tubes are set, the reactant inlet (41) and the reactant outlet (42) are positioned on the same baffle box, the baffle grooves (40) on the baffle box with the reactant inlet (41) are (N/2) -1, and the baffle grooves (40) on the other baffle box are N/2; when the number of the reaction tubes (20) is odd, the number is N, the reactant inlet (41) and the reactant outlet (42) are positioned on different baffle boxes, and the baffle grooves (40) on the upper baffle box and the lower baffle box are (N-1)/2.

10. A fixed bed reactor as set forth in claim 1 wherein: the reaction tube (20) is a straight tube or a spiral winding tube.