Fixed Bed Reactor

Abstract

To provide a fixed-bed reactor capable of evenly spreading a raw material supplied inside.SOLUTION: A fixed-bed reactor 1 comprises: a wire mesh demister 6 for collecting liquid droplets L of a gas-liquid two-phase flow M introduced from a top edge of a raw material introducing layer 2 of the fixed-bed reactor 1; a gathering unit 20 for gathering the liquid droplets L collected by the wire mesh demister 6; and a supply unit 30 for supplying the liquid droplets L gathered by the gathering unit 20 to a reaction layer 3 arranged below the raw material introducing layer 2 of the fixed-bed reactor 1 along a centrifugal direction of the fixed-bed reactor 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to fixed bed reactors. [Background technology]

[0002] Fixed-bed reactors are used as devices for reacting raw materials in facilities such as petrochemical plants (see, for example, Patent Document 1). In such fixed-bed reactors, a reaction layer is arranged in the lower part and a raw material introduction layer is arranged in the upper part, and raw materials are supplied into the reactor through a pipe connected above. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-112745 Summary of the Invention [Problem to be solved by the invention]

[0004] In a fixed-bed reactor such as that described in Patent Document 1, a disk-shaped inlet baffle is placed in the raw material introduction layer directly below the inlet of the piping leading to the fixed-bed reactor, and the raw material supplied from above into the reactor is temporarily received by the inlet baffle. For example, depending on the installation conditions of the fixed-bed reactor, such as the shape and bending position of the piping, the raw material may not be supplied evenly across the entire main surface of the inlet baffle. In this case, the raw material does not diffuse evenly inside the fixed-bed reactor, causing uneven supply to the reaction layer and a risk of reduced production.

[0005] An object of the present disclosure is to provide a fixed-bed reactor capable of uniformly dispersing raw materials supplied therein. [Means for solving the problem]

[0006] The present disclosure has the following configuration.

[0007] [1] A fixed bed reactor, a collection section for collecting droplets of the gas-liquid two-phase flow introduced from an upper end of the raw material introduction layer of the fixed-bed reactor; a collecting unit that collects the droplets collected by the collecting unit; a supply section that supplies the droplets collected by the collecting section to a reaction layer disposed below the raw material introduction layer of the fixed-bed reactor along a centrifugal direction of the fixed-bed reactor; A fixed bed reactor comprising:

[0008] [2] The collection unit is a wire mesh demister. [1] The fixed bed reactor according to [1].

[0009] [3] The supply unit a plurality of flow paths provided radially from the collecting section along the centrifugal direction of the fixed-bed reactor, the flow paths allowing the droplets collected by the collecting section to flow in the centrifugal direction; a plurality of discharge holes provided along the extending direction of the flow path, for discharging the droplets flowing through the flow path into a reaction layer of the fixed-bed reactor; having [1] or [2]. The fixed bed reactor according to [1] or [2].

[0010] [4] The collecting unit is a plate portion provided below the collecting portion and receiving the droplets collected by the collecting portion; a through hole provided between the upper surface and the lower surface of the plate portion; a reservoir provided below the plate portion and configured to store the droplets supplied from the through-holes; and Each of the flow paths of the supply unit is connected to the reservoir at a position a predetermined distance above a bottom surface of the reservoir. [3] The fixed bed reactor according to [3].

[0011] [5] The collecting unit is a plate portion provided below the collecting portion and receiving the droplets collected by the collecting portion; a through hole provided between the upper surface and the lower surface of the plate portion; a guide portion disposed below the plate portion, the guide portion having a plurality of guide grooves radially formed along the centrifugal direction, the guide portion guiding the droplets supplied from the through holes along the guide grooves in the centrifugal direction; and Each of the flow paths of the supply section is connected to an end of the guide section in the centrifugal direction. [3] The fixed bed reactor according to [3].

[0012] [6] The plate portion of the collecting portion is The collecting portion has a flat plate shape on which it is placed, a dam portion erected from the upper surface and formed to surround the entire outer periphery of the collecting portion, The through hole is provided within a range surrounded by the dam portion. [4] or [5]. The fixed bed reactor according to [4] or [5].

[0013] [7] The plate portion of the collecting portion is formed so that the position of the through hole is lowest and is inclined toward the position of the through hole. [4] or [5]. The fixed bed reactor according to [4] or [5].

[0014] [8] The flow path is a conduit whose tip in the centrifugal direction is closed. [3] The fixed-bed reactor according to any one of [7] to [8].

[0015] [9] In some of the plurality of flow paths, the discharge holes are provided only in outer portions in the centrifugal direction. [3] The fixed-bed reactor according to any one of [3] to [8].

[0016]

[10] The number of the discharge holes on the outer side in the centrifugal direction of the flow path is greater than the number on the inner side. [3] The fixed-bed reactor according to any one of [3] to [8].

[0017]

[11] The discharge hole is provided so that the outer diameter in the centrifugal direction of the flow path is larger than the inner diameter. [3] The fixed-bed reactor according to any one of [3] to [8].

[0018]

[12] A branch flow path branching from the tip of the flow path in the centrifugal direction in the circumferential direction of the fixed-bed reactor, the branch flow path is provided with a discharge hole for discharging the droplets introduced from the flow path into a reaction layer of the fixed-bed reactor. [3] The fixed-bed reactor according to any one of [3] to [8]. [Effects of the Invention]

[0019] According to the present disclosure, it is possible to provide a fixed bed reactor capable of uniformly diffusing raw materials supplied therein. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a longitudinal cross-sectional view showing a schematic configuration of a fixed-bed reactor according to a first embodiment. [Figure 2] An enlarged perspective view of the vicinity of the raw material introduction layer of the fixed-bed reactor [Figure 3] FIG. 1 is a plan view showing the configuration inside the raw material introduction layer of the fixed-bed reactor according to the first embodiment. [Figure 4] Schematic diagram illustrating the mechanisms of the collection unit, collection unit, and supply unit of the first embodiment. [Figure 5] FIG. 1 is an exploded perspective view of elements arranged in a raw material introduction layer of a fixed-bed reactor according to a first embodiment. [Figure 6] Schematic diagram showing symbols corresponding to the dimensions in the fixed-bed reactor of the first embodiment. [Figure 7] Schematic diagram showing symbols corresponding to the dimensions in the fixed-bed reactor of the first embodiment. [Figure 8] Schematic diagram showing symbols corresponding to the dimensions in the fixed-bed reactor of the first embodiment. [Figure 9] Schematic diagram showing symbols corresponding to the dimensions in the fixed-bed reactor of the first embodiment. [Figure 10] Schematic diagram showing symbols corresponding to the dimensions in the fixed-bed reactor of the first embodiment. [Figure 11] FIG. 1 is a diagram showing an example of the dimensions of each element in a fixed-bed reactor according to a first embodiment. [Figure 12]FIG. 1 is a perspective view showing a schematic configuration of a fixed-bed reactor according to a second embodiment. [Figure 13] Vertical cross-sectional view of a fixed bed reactor according to a second embodiment [Figure 14] FIG. 10 is a plan view showing the configuration inside the raw material introduction layer of the fixed-bed reactor according to the second embodiment. [Figure 15] FIG. 10 is an exploded perspective view of elements arranged in the raw material introduction layer of the fixed-bed reactor according to the second embodiment. [Figure 16] 10 is a side view of the collecting portion of the second embodiment. [Figure 17] FIG. 10 is a perspective view showing the positional relationship between the guide section of the collecting section and the pipe of the supply section. [Figure 18] FIG. 10 is a plan view showing a schematic configuration of a fixed-bed reactor according to a third embodiment. [Figure 19] FIG. 10 is a plan view showing a schematic configuration of a fixed-bed reactor according to a fourth embodiment. [Figure 20] 20A and 20B are diagrams showing examples of the shapes of the branch flow paths in FIG. 19; [Figure 21] FIG. 1 shows the internal configuration of a fixed-bed reactor of a comparative example. [Figure 22] Graph showing droplet flux distribution on a plane including the tube plate surface in the example and comparative example. [Figure 23] 1 is a diagram showing the distribution of cross-sectional gas flow velocity vectors in the vertical cross sections of fixed-bed reactors of Examples and Comparative Examples. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicated descriptions will be omitted.

[0022] In the following description, the x, y, and z directions are perpendicular to each other. The x and y directions are horizontal directions, and the z direction is vertical. The x direction is the axial direction of the horizontal portion 41 of the pipe 4. For ease of explanation, the positive z direction may also be referred to as the upper side, and the negative z direction may also be referred to as the lower side.

[0023] [First embodiment] The schematic configuration of the fixed-bed reactor 1 according to the first embodiment will be described with reference to Figures 1 to 3. Figure 1 is a vertical cross-sectional view showing the schematic configuration of the fixed-bed reactor 1 according to the first embodiment. Figure 2 is an enlarged perspective view of the vicinity of the raw material introduction layer 2 of the fixed-bed reactor 1. Figure 3 is a plan view showing the configuration inside the raw material introduction layer 2 of the fixed-bed reactor 1 according to the first embodiment.

[0024] FIG. 1 shows an example of a fixed-bed reactor 1 in which the fixed-bed reactor 1 is a multi-tubular fixed-bed reactor. The fixed-bed reactor 1 has a raw material introduction layer 2 at its upper end and a reaction layer 3 at its lower end. The raw material introduction layer 2 and the reaction layer 3 are separated by a tube plate surface 7. A pipe 4 is connected to the upper end of the raw material introduction layer 2, through which a gas-liquid two-phase flow M (a mixed fluid consisting of a continuous phase gas G and a dispersed phase liquid droplets L) is introduced into the raw material introduction layer 2. The fixed-bed reactor 1 reacts the raw material supplied to the raw material introduction layer 2 through the pipe 4 with a catalyst in the reaction layer 3, and discharges the reaction product from below. In the case of the multi-tubular fixed-bed reactor shown in FIG. 1, the reaction layer 3 consists of a reaction tube 8 filled with a solid catalyst or the like and a heat transfer medium circulating section provided outside the reaction tube 8 for heating and removing heat from the reaction tube 8. Note that the fixed-bed reactor 1 is not limited to a multi-tubular reactor, and may be a reactor in which the entire reaction layer is filled with a solid filler or a solid catalyst.

[0025] The raw material fluid used in the fixed bed reactor 1 of this embodiment is a gas-liquid two-phase fluid M having a gas G as a main component and liquid droplets L as a secondary component. The properties of the gas G are, for example, a temperature of 185°C and a viscosity of 3.5 × 10 -5 Pa·s, density 28 kg / m 3 The droplets L are, for example, a droplet diameter of several μm to several hundred μm and a density of 1000 to 2000 kg / m 3 is.

[0026] The pipe 4 is preferably a curved pipe having a horizontal section 41 extending horizontally and a vertical section 42 bent at a substantially right angle from the horizontal section 41 and connected to the fixed-bed reactor 1. An example of the pipe 4 having such a structure is a single-elbow type pipe in which two straight pipes are connected by a joint pipe (elbow) bent at 90 degrees. Note that a type of pipe other than a single elbow, such as a double elbow type, may also be used for the pipe 4.

[0027] In this embodiment, the pipe 4 is arranged such that the horizontal part 41 has an axis in the x direction, and the vertical part 42 has an axis in the z direction. As shown in Figures 2 and 3, the cross section of the pipe 4 is approximately circular, the fixed-bed reactor 1 has an approximately cylindrical shape with its central axis in the z direction, and the vertical part 42 of the pipe 4 is connected to the center of the fixed-bed reactor 1 so that its axis coincides with the center position C of the approximately circular end face above the pipe 4.

[0028] With such a configuration of the piping 4, the gas-liquid two-phase flow M passing through the piping 4 is introduced vertically downward from above into the center of the fixed-bed reactor 1, as shown by the dotted line in FIG.

[0029] An inlet baffle 5 is provided inside the raw material introduction layer 2. The inlet baffle 5 is a horizontally disposed flat plate, with one main surface 51 facing vertically upward (positive z direction). The inlet baffle 5 has a circular plate shape in FIG. 1 and is disposed opposite an inlet 43 of the pipe 4 to the fixed-bed reactor 1. More specifically, the inlet 43 of the pipe 4 is disposed directly above the center position C of the inlet baffle 5. The center position C of the circular main surface 51 of the inlet baffle 5 is the same as the center position C of the fixed-bed reactor 1. That is, in a plan view, the inlet 43 of the pipe 4, the inlet baffle 5, and the outer shape of the fixed-bed reactor 1 are concentrically disposed as shown in FIG. 3.

[0030] A conventional inlet baffle 5 is disposed between the inlet 43 of the pipe 4 and the reaction bed 3 in order to prevent the raw material (gas-liquid two-phase flow M) introduced from the pipe 4 from directly colliding with the reaction bed 3 below and damaging the reaction bed 3. The inlet baffle 5 is generally disposed perpendicular to the flow of the gas-liquid two-phase flow M for the purpose of buffering. As a result, as shown in Fig. 1, a portion of the raw material M introduced from the pipe 4 first collides with the inlet baffle 5, is reflected, and is then decelerated before being supplied to the reaction bed 3.

[0031] In addition, inlet baffle 5 according to this embodiment has dam portion 53 standing upright around the entire outer periphery of the circular shape. Weir portion 53 is a thin plate whose circumferential thickness is approximately the same as the thickness of the inlet baffle in the vertical direction, and has a substantially cylindrical shape.

[0032] In this embodiment in particular, a wire mesh demister 6 (collection portion) is placed on top of the upper surface 51 of the inlet baffle 5 formed in this manner. The wire mesh demister 6 is formed in a substantially cylindrical shape, and the top and bottom surfaces are formed in a circular shape that is substantially the same as the upper surface 51 of the inlet baffle 5. The lower portion of the wire mesh demister 6 is surrounded by the weir portion 53 of the inlet baffle 5.

[0033] The wire mesh demister 6 functions as a collector that collects droplets L of the gas-liquid two-phase flow M introduced from the upper end of the raw material introduction layer 2 of the fixed-bed reactor 1. Fig. 4 is a schematic diagram illustrating the mechanisms of the collector, collecting unit, and supply unit of the first embodiment.

[0034] The wire mesh demister 6 is a separation promoter that enhances the effectiveness of the separation action (fractional distillation and rectification), and in this embodiment, it is a type of spray separator that collects and separates droplets L contained in the gas-liquid two-phase flow M using filaments within the wire mesh demister 6. As shown in Fig. 4, the droplets L collected by the wire mesh demister 6 fall below the demister due to gravity when they reach an appropriate size. On the other hand, most of the gas G contained in the gas-liquid two-phase flow M is reflected by the upper surface 51 of the inlet baffle 5 after passing through the wire mesh demister 6, and moves from the outer periphery of the inlet baffle 5 to the reaction bed 3 below, as shown by the dashed line in Fig. 1 and the dotted line in Fig. 4, for example.

[0035] The wire mesh demister 6 is made of, for example, stainless steel wire (SUS304, 304L, 316, 316L), titanium, aluminum, Inconel, Monel, nickel, copper, or the like.

[0036] The wire mesh demister 6 has a void ratio of, for example, 94% to 99%, which provides it with features such as a very light weight, a large surface area, and a small pressure loss.

[0037] It should be noted that the wire mesh demister 6 may be replaced with something other than the wire mesh demister 6, such as an air filter, as long as it can function as a collection section.

[0038] The fixed bed reactor 1 of this embodiment includes a collecting section 20 below the wire mesh demister 6 as a collecting section, which collects the droplets L collected by the wire mesh demister 6.

[0039] The collecting section 20 will be described with reference to Fig. 5 in addition to Fig. 1 to Fig. 4. Fig. 5 is an exploded perspective view of elements arranged in the raw material introduction layer 2 of the fixed bed reactor 1 of the first embodiment.

[0040] As shown in FIGS. 1 to 5, in the first embodiment, the concentrating section 20 includes the above-mentioned inlet baffle 5 (plate section), through-hole 9, introduction pipe 10, and reservoir 11 as elements thereof.

[0041] As described above, the inlet baffle 5 is provided below the wire mesh demister 6, and receives the liquid droplets L collected by the wire mesh demister 6, as shown in FIG.

[0042] The inlet baffle 5 of this embodiment is in the form of a flat plate on which the wire mesh demister 6 is placed. As shown in Figures 2 to 5, the inlet baffle 5 has a weir portion 53. The weir portion 53 stands upright from the upper surface 51 of the inlet baffle 5 and is formed to surround the entire outer periphery of the wire mesh demister 6.

[0043] Through hole 9 is provided so as to penetrate between upper surface 51 and lower surface 52 of inlet baffle 5. Through hole 9 is provided within the range of the main surface of inlet baffle 5 that is surrounded by weir portion 53. When inlet baffle 5 is disk-shaped, through hole 9 is preferably provided at the center thereof.

[0044] By providing the weir portion 53 and the through holes 9 in this manner, the inlet baffle 5 can efficiently collect the droplets L that fall from the wire mesh demister 6 onto the upper surface 51 of the inlet baffle 5. The weir portion 53 prevents the droplets L that fall onto the upper surface 51 of the inlet baffle 5 from leaking out from the outer edge. The through holes 9 are provided within the area surrounded by the weir portion 53, preferably at its center. Therefore, no matter where the droplets L fall within the area surrounded by the weir portion 53, the distance to the through holes 9 is approximately the same, making it easy to collect the droplets L evenly from the through holes 9 regardless of the drop position.

[0045] The weir portion 53 of the inlet baffle 5 may have a shape that can surround at least the outer periphery of the wire mesh demister 6, and may be configured to be located at a position other than the outer periphery of the inlet baffle 5. For example, if the outer shape of the wire mesh demister 6 is smaller than that of the inlet baffle 5, the weir portion 53 may be configured to be located closer to the center than the outer periphery of the inlet baffle 5, to match the outer shape of the wire mesh demister 6. Alternatively, if the shapes of the wire mesh demister 6 and the inlet baffle 5 are different, the weir portion 53 may be shaped to match the outer shape of the wire mesh demister 6.

[0046] The upper end of the inlet pipe 10 is connected to the position of the through-hole 9 on the lower surface 52 of the inlet baffle 5, and the lower end is connected to the reservoir 11. The inlet pipe 10 is formed in the shape of a circular pipe extending in the vertical direction, as shown in FIG. 5, for example. This allows the liquid droplets L that enter the inlet pipe 10 from the through-hole 9 to easily flow down into the reservoir 11 below due to their own weight.

[0047] As shown by the two-dot chain line in Fig. 1 and as shown in Fig. 4, the introduction pipe 10 introduces droplets L that the inlet baffle 5 receives from the wire mesh demister 6 and drops through the through-holes 9 into the reservoir 11 below. At this time, the introduction pipe 10 can also introduce a portion of the gas G into the reservoir 11 in addition to the droplets L of the gas-liquid two-phase flow, as shown by the dotted line in Fig. 4.

[0048] The reservoir 11 is provided below the inlet baffle 5 and stores the droplets L supplied from the through-holes 9 via the introduction pipe 10. The reservoir 11 is formed in a hollow cylindrical shape, for example, as shown in FIG.

[0049] The fixed-bed reactor 1 of this embodiment also includes a supply unit 30. The supply unit 30 supplies the droplets L collected by the collecting unit 20 to the reaction bed 3 disposed below the raw material introduction bed 2 of the fixed-bed reactor 1 along the centrifugal direction of the fixed-bed reactor 1.

[0050] As shown in FIGS. 1, 4, and 5, the supply unit 30 has a pipe line 12 (flow path) and a nozzle 13 (discharge hole).

[0051] A plurality of pipes 12 are provided radially from the collecting section 20 along the centrifugal direction of the fixed-bed reactor 1, and cause the droplets collected by the collecting section 20 to flow in the centrifugal direction. Each of the plurality of pipes 12 is connected to the side of a cylindrical reservoir 11, as shown in, for example, FIG. 4. The number of pipes 12 can be appropriately set depending on the diameter ds of the pipes 12 (see FIG. 10), the outer diameter dp of the reservoir 11 (see FIG. 9), and the inner diameter D of the fixed-bed reactor 1 (see FIGS. 6 and 7), and is, for example, 8 to 36.

[0052] A plurality of nozzles 13 are provided along the extension direction of the conduit 12. The nozzles 13 extend, for example, in the vertical direction, are connected to the lower part of the conduit 12, and have nozzle holes 14 that communicate from the inside of the conduit 12 to the lower part of the nozzles 13 (see FIG. 10). The nozzles 13 eject droplets L flowing through the conduit 12 into the reaction layer 3 below through the nozzle holes 14. The plurality of nozzles 13 provided in the same conduit 12 are arranged, for example, at approximately equal intervals along the extension direction of the conduit 12.

[0053] The supply unit 30 has such a configuration including the pipe 12 and the nozzle 13, and can spray the droplets L in a fine mist state over the entire reaction layer 3, like a so-called existing mist shower.

[0054] As shown in FIG. 4, each of the conduits 12 of the supply unit 30 communicates with the reservoir 11 at a position a predetermined distance above the bottom surface of the reservoir 11 of the collecting unit 20. With this configuration, droplets L supplied from the inlet pipe 10 to the reservoir 11 below are temporarily stored in the reservoir 11. Then, when droplets L are stored more than a predetermined distance (hj shown in FIG. 10) from the bottom surface, the excess droplets L overflow from the reservoir 11 and are introduced into the conduit 12. This makes it possible to prevent the droplets L introduced from the inlet pipe 10 from being directly supplied to the conduit 12, and to adjust the amount of droplets L supplied from the reservoir 11 to the conduit 12. Furthermore, droplets L can be supplied evenly to each of the multiple conduits 12.

[0055] The pipes 12 are each substantially linear and are preferably arranged substantially uniformly in the circumferential direction of the circular horizontal cross section of the fixed-bed reactor 1, as shown in Figures 3 and 5. This allows the droplets L supplied from the reservoir 11 to be supplied more uniformly throughout the reaction bed 3.

[0056] It is preferable that the tip of the conduit 12 in the centrifugal direction is closed. As described above, the liquid droplets L and a portion of the gas G are introduced into the conduit 12. If the tip of the conduit 12 is closed, the route for the gas G introduced into the conduit 12 to escape to the outside is limited to the nozzle 13. Since a plurality of nozzles 13 are provided along the extension direction of the conduit 12, the gas G flows from the base end of the conduit 12 on the reservoir 11 side toward the tip. By utilizing this flow of gas G within the conduit 12, the liquid droplets L can be more reliably moved to the tip of the conduit 12. Furthermore, if the tip of the conduit 12 is closed, the pressure within the conduit 12 can be more easily increased by the pressure of the gas G. By increasing the pressure within the conduit 12, the liquid droplets L within the conduit 12 can be ejected from the nozzle 13 at a higher pressure, allowing the liquid droplets L to be sprayed over a wider area. In this way, by using a conduit 12 with a closed end in the centrifugal direction as the supply section 30, the droplets L supplied from the reservoir 11 can be moved more reliably in the centrifugal direction, and since they can be ejected from the nozzle 13 over a wider area, the droplets L can be distributed more evenly throughout the reaction layer 3.

[0057] Furthermore, the conduit 12 is preferably disposed at an incline such that the position of the tip end in the centrifugal direction is downward relative to the base end connected to the reservoir 11. This makes it easier to move the droplets L supplied from the reservoir 11 in the centrifugal direction.

[0058] The conduit 12 may be any flow path that can at least cause the droplets L to flow in the centrifugal direction, and may be, for example, a gutter-shaped flow path that does not have the upper half of the pipe.

[0059] Figs. 6 to 10 are schematic views showing the symbols corresponding to the respective dimensions in the fixed bed reactor 1 of the first embodiment. Fig. 6 is a longitudinal sectional view similar to Fig. 1, and Fig. 7 is a plan view similar to Fig. 3. Fig. 8 is a perspective view of the inlet baffle 5 and the wire mesh demister 6. Fig. 9 is a schematic view of the introduction pipe 10 and the reservoir 11. Fig. 10 is a schematic view of the pipeline 12 and the nozzle 13 of the supply unit 30.

[0060] As shown in Figs. 6 and 7, let the pipe diameter be d and the reactor diameter be D. As shown in Fig. 6, let the vertical coordinate of the inlet baffle 5 with respect to the tube plate surface 7 be h, the height from the tube plate surface 7 to the upper end of the raw material introduction layer 2 be H, and the height from the tube plate surface 7 to the bottom surface of the reservoir 11 be hs. As shown in Fig. 7, let the diameter of the inlet baffle 5 be db.

[0061] As shown in Fig. 7, in a plan view, the pipe 4, the inlet baffle 5, and the fixed bed reactor 1 are all arranged so as to have the same center C. As shown in Fig. 6, the installation position h / H (0 ≦ h / H ≦ 1) of the inlet baffle 5 is preferably 0.2 or more and 0.8 or less. The diameter db of the inlet baffle 5 is preferably 0.5D or less and larger than the pipe diameter d.

[0062] As shown in Figs. 6 and 8, let the height of the wire mesh demister 6 be hw. As shown in Fig. 8, let the diameter of the wire mesh demister 6 be dw, the thickness of the inlet baffle 5 be hb, and the height of the weir portion 53 of the inlet baffle 5 be hd.

[0063] The diameter dw of the wire mesh demister 6 is substantially the same as the diameter db of the inlet baffle 5, but is preferably slightly smaller than db in consideration of the fitting with the weir portion 53. The height hd of the weir portion 53 is preferably 10 mm < hd < hw / 3. The height hw of the wire mesh demister 6 is preferably hw < H - h - hb. That is, the height hw of the wire mesh demister 6 is preferably smaller than the value obtained by subtracting the height h of the inlet baffle 5 from the tube plate surface 7 and the thickness hb of the inlet baffle 5 from the height H of the raw material introduction layer 2.

[0064] As shown in Fig. 9, let the diameter of the introduction pipe 10 be di, the diameter of the reservoir 11 be dp, the height of the introduction pipe 10 be hi, and the height of the reservoir 11 be hp.

[0065] The diameter di of the introduction pipe 10 is preferably less than 20 mm. The diameter dp of the reservoir 11 is preferably such that di < dp < 100 mm. The height hi of the introduction pipe 10 is preferably such that hi / 2 ≤ h / 3. That is, the height hi of the introduction pipe 10 is preferably less than half of the height h from the pipe plate surface 7 to the inlet baffle 5. The height hp of the reservoir 11 is preferably about 50 mm < hp < 100 mm. Also, the height hs from the pipe plate surface 7 to the bottom surface of the reservoir 11 shown in Fig. 6 is hs = h - hi - hp.

[0066] As shown in Fig. 10, let the pipe diameter of the pipeline 12 be ds, the length from the base end to the tip end of the pipeline 12 on the reservoir 11 side be L1, the distance between two adjacent nozzles 13 among the plurality of nozzles 13 provided in the single pipeline 12 be L2, the inclination angle of the pipeline 12 (the angle formed by the horizontal direction and the extending direction of the pipeline 12) be θ, and the height from the bottom surface of the reservoir 11 to the connection position of the pipeline 12 be hj.

[0067] The pipe diameter ds of the pipeline 12 is preferably about 10 mm to 20 mm. The length L1 of the pipeline 12 is preferably less than 0.5×(D - dp). That is, the length L1 of the pipeline 12 is preferably less than half of the value obtained by subtracting the diameter dp of the reservoir 11 from the diameter D of the reactor 1. The distance L2 between the nozzles 13 is preferably 0.1×D / 2 to 0.2×D / 2. That is, the distance L2 between the nozzles 13 is preferably about 0.1 to 0.2 times the radius of the reactor 1. The inclination angle θ of the pipeline 12 is preferably 160° < θ < 180°, and more preferably 175° < θ < 180°. The height hj from the bottom surface of the reservoir 11 to the connection position of the pipeline 12 is preferably 10 mm or less.

[0068] Fig. 11 is a diagram showing an example of the dimensions of each element in the fixed-bed reactor 1 of the first embodiment. Fig. 11 shows symbols for each dimension described with reference to Figs. 6 to 10 and examples of the dimensions. Among the example dimensions shown in Fig. 11, when attention is focused on the pipe diameter d, the baffle system db, and the reactor diameter D, it is preferable that the ratio of these three dimensions be set to satisfy d:db:D ≈ 1:5:10.

[0069] In this embodiment, the gas-liquid two-phase flow M of the raw material preferably has a fluid velocity of 8 to 15 m / s when passing through the pipe 4. The droplet concentration of the gas-liquid two-phase flow M is preferably less than 10% by volume.

[0070] As shown in FIGS. 6 to 11, by applying these various parameter conditions, the raw material (gas-liquid two-phase flow M) supplied to the inside of the fixed-bed reactor 1 can be dispersed more uniformly.

[0071] The fixed-bed reactor 1 applied to this embodiment may be of a single-tube or multi-tube type. In the case of a single-tube reactor, there are no restrictions on the outer diameter or length of the reactor, and these are determined arbitrarily from the viewpoints of ensuring the mass velocity and the diffusion of materials into the reactor. In a fixed-bed flow reaction in which reaction raw materials are continuously brought into contact with a heterogeneous solid catalyst, a multi-tube reactor is usually used when the reaction is exothermic or endothermic. In the case of a multi-tube reactor, the reaction tubes are usually cylindrical straight tubes with the same outer diameter, wall thickness, and length, and the inner diameter of the reaction tube is preferably determined to be at least four times the diameter of the catalyst to be packed therein. In industrial applications, this is selected from the range of about 15 to 50 mm, but is not particularly limited.

[0072] There are no particular limitations on the reactions to which the fixed-bed reactor 1 of this embodiment can be applied. Any reaction that is generally carried out in a fixed-bed reactor may be used, such as the production of ethylene oxide by oxidation of ethylene, the production of acrolein and acrylic acid by oxidation of propylene, the production of methacrolein and methacrylic acid by oxidation of isobutylene, the production of maleic anhydride by oxidation of benzene, the production of ethyleneimine by dehydration of monoethanolamine, the production of N-vinyl-2-pyrrolidone by dehydration of N-(2-hydroxyethyl)-2-pyrrolidone, the production of acrylonitrile by ammoxidation of propylene, and the production of acetic acid by direct addition of acetic acid to ethylene. Examples of suitable applications include the production of ethyl acetate, the oxidative acetoxylation of ethylene to produce vinyl acetate, the oxidative acetoxylation of propylene to produce allyl acetate, the hydrogenation of acetylene to produce ethylene, the hydrogenation of benzene to produce cyclohexane, the hydrogenation of ethylbenzene to produce styrene monomer, the dehydrogenation of propane to produce propylene, the isomerization of 1-butene to produce 2-butene, the isomerization of propylene oxide to produce allyl alcohol, the hydration of ethylene to produce ethanol, and the hydration of propylene to produce 2-propanol. Furthermore, application to reactions in which a gas-liquid two-phase flow is introduced into a reactor is more preferred, and specific examples include the oxidative acetoxylation of ethylene to produce vinyl acetate and the oxidative acetoxylation of propylene to produce allyl acetate.

[0073] [Second embodiment] The second embodiment will be described with reference to Figs. 12 to 17. Fig. 12 is a perspective view showing a schematic configuration of a fixed-bed reactor 1A according to the second embodiment. Fig. 13 is a vertical cross-sectional view of the fixed-bed reactor 1A according to the second embodiment. Fig. 14 is a plan view showing the configuration inside the raw material introduction layer 2 of the fixed-bed reactor 1A according to the second embodiment. Fig. 15 is an exploded perspective view of elements arranged in the raw material introduction layer 2 of the fixed-bed reactor 1 according to the second embodiment. Fig. 16 is a side view of the collecting section 20A according to the second embodiment. Fig. 17 is a perspective view showing the positional relationship between the induction section 16 of the collecting section 20A and the pipeline 12 of the supply section 30.

[0074] The fixed-bed reactor 1A of the second embodiment differs from that of the first embodiment in the configuration of the collecting section 20A. In the second embodiment, the collecting section 20A includes an inlet baffle 5A (plate section), a through hole 9, and a guide section 16 as elements related to the collecting section 20A.

[0075] The inlet baffle 5A is a circular plate-like member, but unlike the first embodiment, it is not a flat plate. The inlet baffle 5A is formed so that the through-hole 9 is at its lowest point and is inclined toward the position of the through-hole 9. When the inlet baffle 5A is circular, it is preferable that the through-hole 9 be provided at the center thereof.

[0076] By forming the inlet baffle 5A in an inclined shape centered on the through-hole 9 in this way, it is possible to efficiently collect the liquid droplets L that fall from the wire mesh demister 6 onto the upper surface 51 of the inlet baffle 5A. As shown by the dashed-dotted line in Figure 16, the liquid droplets L that fall from the wire mesh demister 6 onto the upper surface 51 of the inlet baffle 5A can be easily moved by their own weight toward the through-hole 9. In addition, it is possible to make it difficult for the liquid droplets L that fall onto the upper surface 51 of the inlet baffle 5A to leak out from the outer edge side.

[0077] The guide section 16 is disposed below the inlet baffle 5A. A plurality of guide grooves 17 are provided in the guide section 16, radiating in the centrifugal direction. As shown by the dashed-dotted lines in FIG. 17 , the guide section 16 guides the droplets L supplied from the through-holes 9 along the guide grooves 17 in the centrifugal direction.

[0078] As shown in FIGS. 15 to 17 , the guide section 16 is a circular plate-like member. The guide grooves 17 are formed radially from the center of the guide section 16 in the centrifugal direction. A substantially circular central groove 17A is formed at the center of the guide section 16 where the guide grooves 17 are gathered. The diameter of this central groove 17A is smaller than the diameter of the through-holes 9 of the inlet baffle 5A, for example, about 1 mm. Therefore, as shown in FIG. 16 , a funnel-shaped introduction section 15 is disposed between the central groove 17A and the through-holes 9. The introduction section 15 has an upper end with a diameter approximately equal to the diameter of the through-holes 9 and a lower end with a diameter approximately equal to the central groove 17A. The introduction section 15 ensures that the droplets L falling downward from the through-holes 9 fall into the central groove 17A, thereby ensuring that the droplets L flow into the plurality of guide grooves 17.

[0079] Note that introduction portion 15 may be configured to be formed integrally with inlet baffle 5A. That is, through-hole 9 provided in inlet baffle 5A may be configured to protrude downward from lower surface 52 of inlet baffle 5A, and the diameter of through-hole 9 may be configured to narrow at the lower end.

[0080] Furthermore, the guide section 16 is formed so as to be inclined toward the center, with the highest position being the central position where the central groove 17A where the multiple guide grooves 17 are gathered is located. As a result, the multiple guide grooves 17 are inclined so as to become lower in the centrifugal direction, so that the droplets L supplied to the guide grooves 17 can easily flow to the outer edge of the guide section 16 by their own weight.

[0081] The taper angle of guide portion 16 is preferably, for example, about 0.5°. Furthermore, guide groove 17 preferably has a width of about 0.5 mm and a depth of about 2 to 5 mm. The outer diameter of guide portion 16 is preferably formed to be approximately the same as the diameter db of inlet baffle 5A.

[0082] The guide grooves 17 are each substantially linear and are preferably arranged substantially uniformly in the circumferential direction of the circular horizontal cross section of the fixed-bed reactor 1, as shown in Figures 15 to 17. This allows the droplets L supplied from the through-holes 9 of the inlet baffle 5A to be supplied more uniformly throughout the reaction bed 3.

[0083] The number of guide grooves 17 can be appropriately set depending on the width of the guide grooves 17, the diameter ds of the pipe line 12 (see Figure 10), the outer diameter of the guide section 16, the inner diameter D of the fixed-bed reactor 1 (see Figures 6 and 7), etc., and is, for example, 8 to 36.

[0084] Each of the conduits 12 of the supply unit 30 is connected to the centrifugal end of the guide unit 16. More specifically, the guide unit 16 is housed in a cylindrical housing 18 with a bottom. The upper end of the housing 18 is connected to the inlet baffle 5. For example, the inner diameter of the upper opening of the housing 18 is the same as the outer diameter of the inlet baffle 5, and the inlet baffle 5 fits into the upper opening of the housing 18, or the outer edge of the inlet baffle 5 is joined to the upper end of the housing 18, thereby connecting the housing 18 to the inlet baffle 5. Each of the multiple conduits 12 is connected to the side of the cylindrical housing 18 at the position of the outer edge of one of the multiple guide grooves 17, as shown in FIG. 17, for example. Each of the multiple conduits 12 receives droplets L from the connected guide groove 17, moves the droplets L in the centrifugal direction, as shown by the dashed line in FIG. 17, and ejects them from the nozzle 13.

[0085] In the second embodiment, the induction section 16 is formed with approximately the same diameter as the inlet baffle 5A, and therefore the position of the base end of the conduit 12 arranged on the outer periphery of the induction section 16 is approximately the same as the position of the outer diameter of the inlet baffle 5A. Therefore, compared to the first embodiment, it is more difficult to supply droplets L to the center of the reaction layer 3. For this reason, in the second embodiment, as shown in Figures 12 and 13, a closing section 31 is provided at a predetermined diameter from the center C of the reaction layer 3.

[0086] The closing section 31 is configured to prevent the reaction between the raw material and the catalyst by either closing the upper opening of the reaction tube 8 or by not placing the reaction tube 8. By providing such a closing section 31, the reaction between the raw material and the catalyst can be prevented in the central part of the reaction layer 3 where the droplets L are difficult to supply, thereby improving the reaction efficiency. The diameter dc of the closing section 31 is preferably smaller than the diameter db of the inlet baffle 5A.

[0087] In the fixed-bed reactor 1A of the second embodiment, the outer diameter of the induction section 16 may be reduced to approximately the same as the outer diameter dp of the reservoir 11 of the first embodiment. In this case, the base end of the pipe 12 can be positioned closer to the center than the outer diameter of the inlet baffle 5A, so that the droplets L can be supplied also to the center of the reaction bed 3, as in the first embodiment. Therefore, in this case, the reaction efficiency can be maintained even without providing the closing section 31 in the reaction bed 3.

[0088] On the other hand, in the fixed-bed reactor 1 of the first embodiment, the outer diameter dp of the reservoir 11 may be enlarged to the same extent as the outer diameter of the induction section 16 of the second embodiment. In this case, a closing section 31 may be provided in the center of the reaction bed 3 as in the second embodiment, thereby improving the reaction efficiency.

[0089] Furthermore, in the fixed-bed reactor 1A of the second embodiment, the inlet baffle 5A may be replaced with an element, such as the inlet baffle 5 of the first embodiment, in which a weir portion 53 is erected on the outer edge of a flat plate material and a through-hole 9 is provided in the approximate center of the area surrounded by the weir portion 53. Similarly, in the fixed-bed reactor 1 of the first embodiment, the inlet baffle 5 may be replaced with an element, such as the inlet baffle 5A of the second embodiment, which is tapered downward from the outer edge toward the central through-hole 9. This is because both the configurations of the inlet baffles 5 and 5A can exhibit the common effect of facilitating the collection of droplets L in the through-hole 9.

[0090] [Third embodiment] The third embodiment will be described with reference to Fig. 18. Fig. 18 is a plan view showing a schematic configuration of a fixed-bed reactor 1B according to the third embodiment. In Fig. 18, the range where nozzles 13 are provided in the multiple pipes 12, 12A of the supply section 30A is schematically shown by a thick line.

[0091] As shown in Fig. 18, some of the multiple conduits in the supply section 30A, conduits 12A, have nozzles 13 (discharge holes) only on their outer portions in the centrifugal direction. In the example of Fig. 18, conduits 12 in which nozzles 13 are provided over the entire extension direction of the flow path as in the first and second embodiments, and conduits 12A in which nozzles 13 are provided only on their outer portions in the centrifugal direction, are alternately arranged along the circumferential direction of the circular horizontal cross section of the reactor 1B. The region in which nozzles 13 are provided in conduits 12A is, for example, a range outside the outer edge of the inlet baffle 5 as shown in Fig. 13.

[0092] 13, if the outer edge of the inlet baffle 5 is used as the boundary to define the inside and outside, droplets L are sprayed from nine pipes 12 on the inside, and twice as many, or 18 pipes 12, 12A, on the outside. Quantitatively speaking, if the total number of pipes 12, 12A in the supply unit 30 is 2n, droplets L are sprayed from n pipes on the inside and 2n pipes on the outside.

[0093] When multiple nozzles 13 are arranged at approximately equal intervals along the extension direction of the conduits 12 as in the first embodiment, the droplet flux distribution when viewed in horizontal cross section tends to be relatively high in the center and relatively low in the outer periphery (see FIG. 22(B)). This is thought to be due to the shape of the multiple conduits 12 of the supply section 30 extending radially. In contrast, the fixed-bed reactor 1B of the third embodiment is configured so that nozzles 13 are provided only on the outer portions in the centrifugal direction in some conduits 12A of the multiple conduits of the supply section 30A, thereby making it possible to relatively increase the supply amount of droplets L on the outer side in the centrifugal direction relative to the inner side. This can offset the unevenness in the droplet flux distribution caused by the configuration in which the multiple conduits 12 of the supply section 30 extend radially, thereby making the droplet flux distribution more uniform.

[0094] In the example of Figure 18, a configuration is illustrated in which half of the pipes 12A have nozzles 13 only on the outer part in the centrifugal direction, but the proportion of pipes 12A is not limited to this and may be more or less than half.

[0095] Furthermore, in the fixed-bed reactor 1B according to the third embodiment, instead of providing the nozzles 13 only on the outer portions of the conduits 12A in the centrifugal direction, a configuration may be adopted in which the supply amount of droplets L on the outer sides of the supply unit 30A in the centrifugal direction is increased relative to the inner sides by other methods. For example, while all conduits are provided with nozzles 13 throughout their entire extension direction, at least some conduits 12A may be configured so that the number of nozzles 13 on the outer sides of the conduits 12A in the centrifugal direction is greater than the number on the inner sides. Similarly, at least some conduits 12A may be configured so that the outer diameter of the conduits 12A in the centrifugal direction is larger than the inner diameter of the conduits 12A. Similar to the configuration shown in FIG. 18 , these configurations can offset the unevenness in droplet flux distribution caused by the radially extending conduits 12 of the supply unit 30, thereby making the droplet flux distribution more uniform.

[0096] [Fourth embodiment] The fourth embodiment will be described with reference to Figures 19 and 20. Figure 19 is a plan view showing a schematic configuration of a fixed-bed reactor 1C according to the fourth embodiment. Figure 19 shows only a portion of the multiple pipes 12 extending radially from the reservoir 11 shown in Figure 3 and the like.

[0097] 19, the supply section 30B has branch flow paths 12B that branch off in the circumferential direction of the fixed-bed reactor 1 from the centrifugal tips of the multiple pipe lines 12. The branch flow paths 12B are provided with discharge holes 13, similar to the pipe lines 12, that discharge droplets L introduced from the pipe lines 12 into the reaction layer 3 of the fixed-bed reactor 1.

[0098] The circumferential length of each branch flow path 12B is preferably set to a length that does not cause it to come into contact with other branch flow paths 12B installed in adjacent pipelines 12. In addition, in the example of Fig. 19, a pair of branch flow paths 12B are connected to both circumferential sides of one flow path 12, but the branch flow paths 12B may be connected to only one side in the circumferential direction. In addition, in the example of Fig. 19, a configuration in which two nozzles 13 are provided in each branch flow path 12B is illustrated, but the number of nozzles 13 provided in each branch flow path 12B is not limited to this.

[0099] Fig. 20 is a diagram showing an example of the shape of the branch channel 12B in Fig. 19. Fig. 20 shows the shapes of the pipe line 12 and the branch channel 12B when viewed from the extending direction of the pipe line 12 (the radial direction of the fixed-bed reactor 1C).

[0100] 20(A), the branch flow path 12B1 may be formed in a tubular shape extending along the circumferential direction of the fixed-bed reactor 1. In this case, the branch flow path 12B1 is preferably provided so as to be inclined such that the tip side is lower than the base end side connected to the pipeline 12. This makes it easier for the droplets L introduced into the branch flow path 12B1 to move toward the tip side by their own weight, and makes it easier to spray the droplets L more evenly over a wider area via the nozzle 13.

[0101] 20(B), the branch flow channel 12B2 may be formed in a substantially triangular shape that extends along the circumferential direction of the fixed-bed reactor 1 and has a bottom surface that is inclined downward from the tip end side to the base end side. This configuration also makes it easier for the droplets L introduced into the branch flow channel 12B2 to move by their own weight along the inclination of the bottom surface toward the tip end side, making it easier to spray the droplets L more evenly over a wider area through the nozzle 13.

[0102] 20(C), the branch flow path 12B3 may be formed in a substantially rectangular shape that extends along the circumferential direction of the fixed-bed reactor 1 and has a bottom surface located below the pipe line 12. Even with this configuration, the droplets L introduced into the branch flow path 12B3 fall by their own weight toward the bottom surface located below the pipe line 12, which facilitates movement toward the tip side, making it easier to spray the droplets L evenly over a wider range via the nozzle 13.

[0103] The branch flow path 12B may have a shape other than the branch flow paths 12B1, 12B2, and 12B3 shown in FIGS. 20(A) to 20(C).

[0104] As shown in Figures 19 and 20, by providing a branch flow path 12B at the tip of the conduit 12, the supply amount of droplets L on the outer side in the centrifugal direction of the supply section 30B can be increased relatively to the inner side, so that, as with the third embodiment shown in Figure 18, the unevenness in the droplet flux distribution caused by the configuration in which multiple conduits 12 of the supply section 30 extend radially can be offset, and the droplet flux distribution can be made more uniform. [Example]

[0105] A calculation simulation was carried out to confirm the effectiveness of the above embodiment. The main calculation conditions are as follows: Software used: ANSYS (registered trademark) Fluent (registered trademark), a general-purpose computational fluid analysis software from ANSYS, Inc. ·Continuous phase (gas = vapor phase) governing equation: N-S equation, equation of continuity Turbulence model: k-ε model Gas-liquid two-phase flow analysis: Euler-Lagrange type (gas fluid is analyzed using Euler type and liquid droplets using Lagrange type) Dispersed phase flow: Liquid phase Particle Tracking Method (DPM (Discrete Phase Model)): One Way Coupling Analysis object: Piping and reactor

[0106] (1) Example The configuration of the fixed-bed reactor 1 of the first embodiment was used. The dimensions of each main element were the values ​​exemplified in FIG. 11. The ratio of the pipe diameter d, the diameter of the circular bottom plate (diameter db of the inlet baffle 5), and the reactor diameter D was 1:5:10. The position h / H of the inlet baffle 5 was 0.4. The flow velocity of the gas-liquid two-phase flow M was 10 m / s, and the droplet concentration was 5 mass%. Under these conditions, the droplet flux distribution in a plan view of the raw material introduction layer 2 of the fixed-bed reactor 1 was measured. The droplet flux is the product of the droplet concentration and the vertical gas flow velocity (droplet concentration × gas flow velocity).

[0107] (2) Comparative Example Fig. 21 is a diagram showing the internal configuration of a fixed-bed reactor 1D of a comparative example. As shown in Fig. 21, the fixed-bed reactor 1D of the comparative example has the configuration of a conventional fixed-bed reactor described in Patent Document 1 and the like, and includes a well-known flat-plate inlet baffle 5, but differs from the example in that it does not include the wire mesh demister 6, collecting section 20, and supply section 30 provided in the above embodiment. The other simulation conditions were the same as those of the example.

[0108] Fig. 22 shows the droplet flux distribution in a plane including the tube plate surface 7 for the Example and the Comparative Example. Fig. 22(A) shows the results for the Comparative Example, and Fig. 22(B) shows the results for the Example. Fig. 22 shows the distribution such that the smaller the droplet flux, the closer to white the color, and the larger the droplet flux, the closer to black the color.

[0109] As shown in the comparative example in FIG. 22(A), in the absence of the wire mesh demister 6 as a collection unit, the collecting unit 20, and the supply unit 30, the droplet flux is biased to the left side of the figure (the region opposite the horizontal portion 41 of the pipe 4), and the standard deviation of the droplet flux over the entire plane is 3.7 × 10 -5 22(B), it can be seen that there is unevenness in the droplet flux across the entire plane. On the other hand, in the example shown in FIG. 22(B), in the state where the wire mesh demister 6 as a collector, the collecting section 20, and the supply section 30 are present, the number of dark areas is reduced compared to (A), and it can be seen that the overall unevenness is suppressed. The standard deviation of the droplet flux across the entire plane is 1.1 × 10 -5 This is about one-third the size of (A).

[0110] As described above, the results of the example and comparative example shown in FIG. 22 demonstrate that by providing the wire mesh demister 6 above the inlet baffle 5 and providing the collecting section 20 and the supply section 30 below, the droplet flux distribution in the raw material introduction layer 2 of the fixed-bed reactor 1 in a plan view can be made uniform, and the gas-liquid two-phase flow M of the raw material supplied inside can be uniformly diffused.

[0111] Fig. 23 shows the distribution of cross-sectional flow velocity vectors of gas G in the vertical cross sections of the fixed-bed reactors 1 and 1D of the Example and the Comparative Example. (A) in Fig. 23 shows the results of the Comparative Example, and (B) shows the results of the Example. In Fig. 23, the direction of the flow velocity at each position inside the fixed-bed reactors 1 and 1D is shown by arrows.

[0112] 23(A), in a state where there is no wire mesh demister 6 as a collector, most of the gas G collides with the upper surface of the inlet baffle 5 and then flows at high density in the centrifugal direction along the upper surface of the inlet baffle 5, generating vortex flows in the space on the upper outer periphery of the inlet baffle 5 and in the space between the inlet baffle 5 and the tube plate surface 7. As a result, the gas-liquid two-phase flow M stagnates in the raw material introduction layer 2, the flow field in the vicinity of the tube plate surface 7 becomes non-uniform, and the supply rate of the gas-liquid two-phase flow M to the reaction layer 3 becomes sparse and uneven.

[0113] On the other hand, in the embodiment shown in Figure 23(B), when a wire mesh demister 6 is used as a collector, the direction of the flow velocity vector of the gas G is dispersed as it passes through the wire mesh demister 6 before hitting the inlet baffle 5, thereby suppressing the generation of vortex flows compared to (A). As a result, the gas G of the gas-liquid two-phase flow M reflected by the inlet baffle 5 moves smoothly downward without stagnation in the raw material introduction layer 2. This makes it clear that the flow field near the tube sheet surface 7 is uniform, creating an environment favorable for droplet feeding. As a result, the droplets L contained in the gas-liquid two-phase flow M sprayed from the collecting section 20 and the supply section 30 over the entire reaction layer 3 also move smoothly downward, thereby suppressing overall unevenness in the supply amount of the gas-liquid two-phase flow M to the reaction layer 3.

[0114] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Design modifications to these specific examples made by a person skilled in the art as appropriate are also included within the scope of the present disclosure as long as they comprise the features of the present disclosure. The elements of the above-described specific examples, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and can be modified as appropriate. The elements of the above-described specific examples can be combined in various ways as appropriate, as long as no technical contradictions arise.

[0115] In the above embodiment, a single through-hole 9 is provided at approximately the center of the circular shape of the inlet baffle 5, 5A, and droplets L of the gas-liquid two-phase flow M are guided to the lower collecting section 20, 20A through this through-hole 9. However, a plurality of through-holes 9 may be provided. In this case, the plurality of through-holes 9 are preferably arranged within the range of the diameter dp of the lower reservoir 11 and the outer diameter of the guide section 16 in plan view. [Explanation of symbols]

[0116] 1, 1A, 1B Fixed bed reactor 2 Raw material introduction layer 3. Reaction layer 4 Piping 6 Wire mesh demister (collection part) 20, 20A consolidation section 5, 5A Inlet baffle (plate section) 51 Top side 52 Bottom surface 53 Weir 9 Through holes 10 Introductory tube 11 Reservoir 15 Introduction 16 Guidance part 17 Guide groove 18. Cabinet 30, 30A, 30B supply section 12, 12A Pipe (flow path) 12B, 12B1, 12B2, 12B3 Branch flow path 13 Nozzle (discharge hole) 14 nozzle holes 31 Closure M liquid two-phase flow L droplet

Claims

1. A fixed bed reactor comprising: a collection section for collecting droplets of the gas-liquid two-phase flow introduced from an upper end of the raw material introduction layer of the fixed-bed reactor; a collecting unit that collects the droplets collected by the collecting unit; a supply section that supplies the droplets collected by the collecting section to a reaction layer disposed below the raw material introduction layer of the fixed-bed reactor along a centrifugal direction of the fixed-bed reactor; A fixed bed reactor comprising:

2. The collection unit is a wire mesh demister.

2. The fixed bed reactor of claim 1.

3. The supply unit includes: a plurality of flow paths provided radially from the collecting section along the centrifugal direction of the fixed-bed reactor, the flow paths allowing the droplets collected by the collecting section to flow in the centrifugal direction; a plurality of discharge holes provided along the extending direction of the flow path, for discharging the droplets flowing through the flow path into a reaction layer of the fixed-bed reactor; having The fixed bed reactor according to claim 1 or 2.

4. The collecting unit is a plate portion provided below the collecting portion and receiving the droplets collected by the collecting portion; a through hole provided between the upper surface and the lower surface of the plate portion; a reservoir provided below the plate portion and configured to store the droplets supplied from the through-holes; and Each of the flow paths of the supply unit is connected to the reservoir at a position a predetermined distance above a bottom surface of the reservoir. The fixed bed reactor according to claim 3.

5. The collecting unit is a plate portion provided below the collecting portion and receiving the droplets collected by the collecting portion; a through hole provided between the upper surface and the lower surface of the plate portion; a guide portion disposed below the plate portion, the guide portion having a plurality of guide grooves radially formed along the centrifugal direction, the guide portion guiding the droplets supplied from the through holes along the guide grooves in the centrifugal direction; and Each of the flow paths of the supply section is connected to an end of the guide section in the centrifugal direction. The fixed bed reactor according to claim 3.

6. The plate portion of the collecting portion is The collecting portion has a flat plate shape on which it is placed, a dam portion erected from the upper surface and formed to surround the entire outer periphery of the collecting portion, The through hole is provided within a range surrounded by the dam portion. The fixed bed reactor according to claim 4 or 5.

7. The plate portion of the collecting portion is formed so as to be inclined toward the position of the through hole, with the position of the through hole being the lowest. The fixed bed reactor according to claim 4 or 5.

8. The flow path is a conduit whose tip in the centrifugal direction is closed. The fixed bed reactor according to any one of claims 3 to 7.

9. In some of the plurality of flow paths, the discharge holes are provided only in outer portions in the centrifugal direction. The fixed bed reactor according to any one of claims 3 to 8.

10. The number of the discharge holes provided on the outer side in the centrifugal direction of the flow path is greater than the number of the discharge holes provided on the inner side. The fixed bed reactor according to any one of claims 3 to 8.

11. The discharge hole is provided so that an outer diameter in the centrifugal direction of the flow path is larger than an inner diameter. The fixed bed reactor according to any one of claims 3 to 8.

12. a branch flow path branching from a tip of the flow path in the centrifugal direction in the circumferential direction of the fixed-bed reactor, the branch flow path is provided with a discharge hole for discharging the droplets introduced from the flow path into a reaction layer of the fixed-bed reactor. The fixed bed reactor according to any one of claims 3 to 8.

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