JP7555587B2 - Reactor - Google Patents

Description

The present invention relates to a reactor, and more specifically, to a reactor in which a reaction fluid is introduced into the inlet end of a column packed with a reaction catalyst, reacted in the column, and the reaction product is discharged from the outlet end of the column.

Conventionally, in a reaction apparatus (flow reactor) having a column packed with a reaction catalyst, a filter is provided at both the inlet and outlet openings, and it is known that a resin such as fluororesin or PEEK (polyether ether ketone) is used as a packing that holds the filter at its periphery (see, for example, Patent Documents 1 and 2). It is also known that a filter element made of laminated wire mesh is used as the filter (see, for example, Patent Document 3).

JP 2016-109506 A JP 2014-32134 A Japanese Patent Application Publication No. 7-24227

As shown in Patent Documents 1 and 2, when the packing used around the filter periphery is made of resin, if the filter is a laminated wire mesh filter element as shown in Patent Document 3, it has a high porosity and is less likely to clog. Even if clogging does occur, it can be easily restored by ultrasonic cleaning. However, in flow reactors, columns are sometimes operated at around 200°C, and if the packing is made of resin, it may deform or creep due to its heat resistance, which may cause problems during operation of the reactor.

Therefore, if the packing material is changed from resin to stainless steel and the outer circumference of the filter element is joined to a stainless steel ring by argon welding, a filter with no problems in filtering performance can be obtained. However, argon welding causes "burns" at the welded joint, so pickling after welding is necessary, and there is a concern that this pickling will cause oxides to form in the narrow wire mesh and remain in the mesh.

In this way, a filter that combines a stainless steel ring filter body with a disk-shaped laminated wire mesh can be easily manufactured. Then, in order to measure the temperature during the reaction of the catalyst particles packed in the column, a through hole may be made in the filter and a temperature sensor may be inserted into the through hole. In this case, if only one temperature sensor is inserted, a donut-shaped disk with a hole in the center may be used. However, if it is desired to know the radial distribution of the reaction temperature in the column, multiple temperature sensors must be inserted, and additional through holes for the temperature sensors must be provided near the inner wall of the column. To achieve this, the filter is not disk-shaped, but rather, for example, a D-shaped circle with a cutout and a circular hole provided inside (D-shaped donut shape) (see Figure 3(a)).

In order to weld this D-shaped donut filter, it is necessary to provide a corresponding D-shaped recess (filter fitting recess) in the stainless steel ring filter body. However, if the recess is D-shaped, the radial thickness is not uniform depending on the location, so if the filter and ring are joined by argon welding, the amount of heat stored will differ depending on the location, and the ring as a whole will become distorted after welding. In addition, the occurrence of this distortion causes the flatness of the flange of the ring to be lost, which has an adverse effect on the sealing performance of the ring. In addition, the welded portion of the through hole in the center of the filter is small in diameter, so it will deform during welding, making it difficult to perform argon welding itself.

The present invention aims to provide a reaction device in which a laminated wire mesh filter element and a packing ring (filter body) on the outer periphery can be appropriately welded, and multiple temperature sensors can be inserted in the column of a reaction device such as a flow reactor.

In order to achieve the above object, the reactor of the present invention is a reactor in which a plurality of reaction raw materials are introduced from the inlet end of a column packed with a reaction catalyst, reacted in the column, and a reaction product is discharged from the outlet end of the column, the reactor comprising a pair of column ends provided at both the inlet and outlet ends of the column, a pair of filter members installed between both the inlet and outlet ends of the column and the pair of column ends, and a pair of nuts for fastening the column to the pair of column ends, the outlet side column end having a plurality of ports for supporting a plurality of temperature sensors, respectively, and when the column and the outlet side column end are fastened to each other, the plurality of ports are provided with a plurality of outlets. The outlet filter member is connected to the inside of the column through the inlet filter member, and the outlet filter member is composed of a filter element and a disk-shaped filter body to which the filter element is attached. The filter body is provided with a plurality of sensor insertion parts with holes that respectively communicate with the plurality of ports, and a filter fitting recess that is recessed in an area avoiding the plurality of sensor insertion parts. The filter element is characterized in that a wire mesh layer and a retainer arranged on the surface of the wire mesh layer are integrally fitted into the filter fitting recess, and an annular laser weld is formed on the periphery of the filter fitting recess to join the retainer.

The plurality of ports are comprised of a central port provided on the central axis of the column and an outer periphery port provided on the outer periphery of the central port, the filter body has a central sensor insertion portion corresponding to the central port and an outer periphery sensor insertion portion corresponding to the outer periphery port, these two sensor insertion portions are separated from each other by the filter fitting recess, and the laser weld is formed on the outer periphery edge of the central sensor insertion portion and the inner periphery edge of the outer periphery sensor insertion portion.

Furthermore, the depth of the filter fitting recess corresponds to the thickness of the filter element, and when the filter element is attached to the filter fitting recess, the upper surface of the retainer is flush or concave without protruding from the filter fitting recess, and the laser weld is a full-circumference butt laser weld formed between the peripheral edge of the retainer and the peripheral edge of the filter fitting recess.

According to the reaction device of the present invention, a retainer is provided on the surface of the wire mesh layer that constitutes the filter element, and the retainer and the filter fitting recess are welded by laser welding, so that heat can be released around the weld point, the wire mesh layer below the retainer is protected, and proper welding is performed. Furthermore, the use of laser welding eliminates the need for pickling or cleaning after welding, and there is no need to worry about oxides remaining on the filter.

In addition, even if multiple sensor insertion holes are provided in the outlet filter member, the filter function can be maintained, and the use of multiple temperature sensors can reliably meet the need to know the temperature distribution not only in the longitudinal direction within the column but also in the radial direction.

FIG. 13 is a diagram showing the structure of a disk-shaped filter and a ring in a conventional example. FIG. 13 is a diagram showing a state in which a disk-shaped filter according to a conventional example is welded to a ring. 1 is a cross-sectional view showing a reaction apparatus according to an embodiment of the present invention. FIG. 1 is a diagram showing the configuration of a reaction apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing the structure of a filter in the reaction apparatus of the above embodiment. FIG. 2 is a diagram showing a state in which a filter element in the reactor of the above embodiment is welded to a ring. FIG. 2 is a diagram showing a state before contour formation of each layer constituting a filter element in the reactor of the above embodiment. FIG. 2 is a diagram showing the state after contour formation of each layer constituting the filter element in the reactor of the above embodiment.

As mentioned above, it is difficult to use argon welding to weld the D-shaped filter element and the ring (filter body), so in this invention we attempted to use laser welding. A laser beam has a small welding spot, and melts the base materials together with the power concentrated at the welding point, minimizing the thermal impact on the surrounding area. In addition, laser welding has great advantages, such as not causing distortion or burning, making pickling after welding unnecessary.

However, in the case of a laminated wire mesh filter element, there was a problem that the wires constituting the mesh were burned off due to the concentration of the laser welding power. Figure 1 shows a conventional disk-shaped filter 12. As shown in Figure 1 (a), the filter 12 is made by stacking multiple circular wire mesh layers 2 to 6, heating and compressing them, and then evacuating them to form a vacuum, which diffusion-bonds the wire mesh layers together to form an integrated unit. The wire mesh layers used in this case are, from top to bottom, the protective layer 2, the filtration layer 3, the protective layer 4, the strength layer 5, and the strength layer 6. These wire mesh layers 2 to 6 are integrated by diffusion bonding to form the filter element 1, and then welded to a stainless steel ring (filter body) 10 having a flange 35 (see Figure 1 (b)). Of these, the filtration layer 3 and the protective layers 2 and 4 above and below it have a thin wire diameter, so if laser welding is performed as is, the wires will overheat and burn off, causing pinholes in the wire mesh, which may cause the catalyst particles in the column 7 to leak out. To solve this problem, in the present invention, as shown in FIG. 3(a), a retainer 9 made of a thin stainless steel plate cut into a D-shape is provided on the surface of the wire mesh layers 2 to 6.

The retainer 9 is composed of a hole 39 surrounding the central sensor insertion portion 43, a peripheral portion 40 forming an outline, and a rib portion 41 connecting the hole 39 and the peripheral portion 40. The rib portion 41 has a positioning function for the hole 39, and its area is formed small enough to ensure a sufficient filtration area, and in this embodiment, it is composed of three plate-shaped members extending radially from the hole 39.

When providing the retainer 9 to fabricate the D-shaped filter 13, the retainer 9 is placed on the surface of the multiple wire mesh layers 2 to 6, which are made up of a protective layer 2, a filtration layer 3, a protective layer 4, a strength layer 5, and a strength layer 6, and the whole is integrated by diffusion bonding.

Figure 2 shows a reaction apparatus 100 of this embodiment. As shown in Figures 2(a) and (b), this reaction apparatus 100 includes a column 7 filled with catalyst particles, a pair of column ends 20, 20 provided at both the inlet and outlet ends of the column 7, a conventional disk-shaped filter (inlet side filter member) 12 as shown in Figure 1 provided at the column inlet side, a D-shaped filter (outlet side filter member) 13 provided at the column outlet side, filter O-rings (retaining members) 21, 21, 21, 21 attached to the flanges 35, 36 of each filter to seal between the column 7 and the column ends 20, 20, nuts 22, 22 that secure the column 7 and the column ends 20, 20, two raw material inlet pipes 23, 24, and a product outlet pipe 25. In addition, on the outlet side of the reaction device 100, temperature sensors 26, 26 are inserted into the column 7 via temperature sensor O-rings 27, 27 in each of the two through holes of the D-shaped filter 13.

The column 7 has a tubular main body 28 made of a metal material such as stainless steel, and flanges 29 provided on the outer periphery of both ends of the main body 28. The main body 28 is filled with catalyst particles. A threaded portion 30 is provided on the outer periphery of the flanges 29 for fastening to the nut 22.

The column end 20 has a substantially cylindrical main body 31, a flange 32 provided on the outer periphery of the main body 31 on the column mounting side, and a circular fitting recess 33 provided on the side. A flat surface 34 for fastening to the nut 22 is provided on the outer periphery of the flange 32. The column end 20 on the outlet side is provided with multiple ports for inserting and supporting multiple temperature sensors. In the above embodiment, two ports are provided: a central port 45 provided on the central axis of the column 7, and an outer periphery port 46 provided on the outer periphery of the central port 45.

The filter O-rings 21 are attached to the front and back of the flange 35 of the disk-shaped filter 12 fitted into the fitting recess 33 of the column end 20 on the inlet side, and to the front and back of the flange 36 of the D-shaped filter 13 fitted into the fitting recess 33 of the column end 20 on the outlet side. The inner diameter of the O-ring 21 is set slightly smaller than the outer diameter of each flange 35, 36.

The nut 22 is a connecting part for fastening the column 7 and the column end 20, and has a threaded portion 37 on its inner circumferential surface. The threaded portion 37 engages with the threaded portion 30 of the column 7 to physically fasten the column 7 and the column end 20 together.

The raw material inlet pipes 23 and 24 are pipes provided at the column end 20 on the inlet side. The reaction raw material passes through the disk filter 12 through the raw material inlet pipes 23 and 24 and is then introduced into the column 7, where a reaction occurs via the catalyst particles packed in the column 7.

The product outlet pipe 25 is a pipe provided at the column end 20 on the outlet side, and the product after the reaction in the column 7 passes from the column 7 through the D-shaped filter 13 and is discharged to the outside through the product outlet pipe 25.

The temperature sensor 26 is a sensor for measuring the temperature during the reaction in the column 7, and is inserted into the center of the column 7 and around the inner wall of the column 7. The temperature sensor 26 is held in a sealed state by a temperature sensor O-ring 27 at the penetration part of the column end 20. The temperature sensor 26 inserted into the center of the column 7 passes through a central sensor insertion part 43 provided in the center of the D-shaped filter 13. The temperature sensor 26 inserted around the inner wall of the column 7 passes through an outer sensor insertion part 44 provided in the cutout part 38 of the D-shaped filter 13.

Between the main body 28 of the column 7 and the fitting recesses 33 of the column ends 20, 20, a disk-shaped filter (inlet filter member) 12 is provided on the inlet side, and a D-shaped filter (outlet filter member) 13 is provided on the outlet side, and is held by the flanges 35, 36 of each filter via a filter O-ring (holding member) 21.

The above-mentioned disk-shaped filter (inlet side filter member) 12 is the same filter as the conventional example shown in FIG. 1, and is made by welding a disk-shaped filter element 1 and a stainless steel ring (inlet side filter body) 10.

The D-shaped filter (outlet side filter member) 13 is the filter shown in Figures 3(a) and (b), and is made by welding a D-shaped donut-shaped filter element 8, which is a circle with a part cut out to form a D shape and has a round hole inside, to a stainless steel ring (outlet side filter body) 11.

The stainless steel ring (outlet side filter body) 11 is provided with the above-mentioned center side sensor insertion portion 43, outer peripheral side sensor insertion portion 44, and a D-shaped filter fitting recess 42 that is recessed in the area avoiding these sensor insertion portions. The depth of the filter fitting recess 42 corresponds to the thickness of the filter element 8, so that when the filter element 8 is attached to the filter fitting recess 42, the opening end of the filter fitting recess 42 and the plate surface of the retainer 9 are formed to be flush or slightly concave. This makes it possible to stabilize the attachment state of the D-shaped filter 13 and to uniformly pack the catalyst in the column 7.

When creating the D-shaped donut-shaped filter element 8 of the above embodiment, as shown in FIG. 4(a), a rectangular wire mesh material larger than the filter element 8 is stacked on a retainer material on which a rib portion 41 that cannot be processed later is formed in advance, and these are integrated by diffusion bonding in the same manner as the disk-shaped filter element 1 described above. Then, the inner and outer diameters are cut out using a laser processing machine or the like, to create the outline of a D-shaped donut shape as shown in FIG. 4(b).

In addition, since the cut surfaces of the wires are exposed at the cut surfaces around the wire mesh that is integrated by diffusion bonding, if it is used as a filter as is, there is a risk that the catalyst particles in the column 7 will leak out. To avoid this, only the cut surfaces of the laminated wire mesh may be sealed with argon welding. After sealing, the sealing surfaces are cut and finished to complete the D-shaped donut-shaped filter element 8.

Next, the completed filter element 8 is inserted into the filter fitting recess 42 of the outlet side filter body 11, which has the filter fitting recess 42 machined into a D-shape, and laser welded in an annular shape to weld the retainer 9 part of the filter element 8 to the outlet side filter body 11. The laser welded part is formed on the outer peripheral edge of the center side sensor insertion part 43 and the inner peripheral edge of the outer peripheral side sensor insertion part 44, and a butt joint full circumference laser welded part 47 is formed between the peripheral edge of the retainer 9 and the peripheral edge of the filter fitting recess 42 (see FIG. 3(b)). In this way, the D-shaped filter 13 is completed. In this way, the filter element 8 and the filter body 11 can be properly welded, and multiple temperature sensors can be inserted into the column 7. At this time, no pinholes due to overheating were generated in the welded filter, and no significant distortion occurred in either the filter or the ring.

Therefore, according to the reaction device of the present invention, a retainer is provided on the surface layer of the wire mesh layer that constitutes the filter element, and the retainer and the filter fitting recess are welded by laser welding, so that the retainer provides a sufficient escape route for heat, the wire mesh layer below the retainer is protected, and there is no need to consider the thermal effects on the wire mesh layer, and appropriate welding can be performed. Furthermore, the use of laser welding eliminates the need for pickling or cleaning after welding, and there is no need to worry about oxides remaining on the filter.

In addition, even if multiple sensor insertion holes are provided in the outlet filter member, the filter function can be maintained, and multiple temperature sensors can be used to reliably meet the need to know the temperature distribution in the radial direction, not just the length direction, within the column.

In the above embodiment, the filter is shaped like a D-shaped donut, assuming that two temperature sensors are inserted into the column 7. However, if three or more temperature sensors are inserted, multiple cutouts 38 may be provided in the outlet filter body 11 according to the number of sensors, and the filter may be shaped in a form other than a D-shaped donut. Even when two temperature sensors are inserted, the outlet filter body 11 and the filter fitting recess 42 may be shaped in a form other than a D-shaped form, taking into consideration factors such as securing the filtration area. In addition, all of the wire mesh layers 2 to 6 are not necessarily required, and a filter element can be constructed with a total of three layers, one filtration layer and two coarse layers to protect it. In addition, the retainer 9 has three ribs 41 in the above embodiment, but one or more may be provided, taking into consideration factors such as securing the filtration area.

1: Disk-shaped filter element, 2, 4: Wire mesh layer (protective layer), 3: Wire mesh layer (filtration layer), 5, 6: Wire mesh layer (strength layer), 7: Column, 8: D-shaped donut-shaped filter element, 9: Retainer, 10: Stainless steel ring (inlet side filter body), 11: Stainless steel ring (outlet side filter body), 12: Disk-shaped filter (inlet side filter member), 13: D-shaped filter (outlet side filter member), 20: Column end, 21: Filter O-ring (retaining member), 22: Nut, 23, 24: Raw material inlet piping, 25...・Product outlet pipe, 26...Temperature sensor, 27...O-ring for temperature sensor, 28...Main body, 29...Flange, 30...Threaded portion, 31...Main body, 32...Flange, 33...Fitting recess, 34...Flat portion, 35, 36...Flange, 37...Threaded portion, 38...Notch, 39...Hole, 40...Periphery, 41...Rib, 42...Drilled portion (filter fitting recess), 43...Center sensor insertion portion, 44...Outer sensor insertion portion, 45...Center port, 46...Outer port, 47...Full circumference laser butt weld, 100...Reaction device

Claims (3)

A reactor in which a plurality of reaction raw materials are introduced into an inlet end of a column packed with a reaction catalyst, reacted in the column, and a reaction product is discharged from an outlet end of the column,
a pair of column ends provided at both ends of an inlet/outlet of the column, a pair of filter members inserted between both ends of the inlet/outlet of the column and the pair of column ends, and a pair of nuts fastening the column to the pair of column ends,
the outlet-side column end has a plurality of ports for inserting and supporting a plurality of temperature sensors, respectively, and when the column and the outlet-side column end are fixed to each other, the plurality of ports communicate with the inside of the column via an outlet-side filter member;
The outlet side filter member is composed of a filter element and a disk-shaped filter body to which the filter element is attached,
the filter body is provided with a plurality of sensor insertion portions each having a hole communicating with the plurality of ports, and a filter fitting recess formed by recessing an area avoiding the plurality of sensor insertion portions,
The filter element is configured such that a wire mesh layer and a retainer disposed on a surface of the wire mesh layer are integrally fitted into the filter fitting recess,
A reaction device, characterized in that an annular laser welded portion for joining the retainer is formed on the peripheral edge of the filter fitting recess. the plurality of ports include a central port provided on a central axis of the column and an outer circumferential port provided on the outer circumferential side of the central port;
the filter body has a central sensor insertion portion corresponding to the central port and an outer peripheral sensor insertion portion corresponding to the outer peripheral port, the two sensor insertion portions being separated from each other by the filter fitting recess;
2. The reaction device according to claim 1, wherein the laser welds are formed on an outer periphery of the center sensor insertion portion and an inner periphery of the outer periphery sensor insertion portion. a depth of the filter fitting recess corresponds to a thickness of the filter element, and an upper surface of the retainer is disposed flush or concavely without protruding from the filter fitting recess in a state in which the filter element is attached to the filter fitting recess,
3. The reaction device according to claim 1, wherein the laser weld is a full circumference butt weld formed between a peripheral edge of the retainer and a peripheral edge of the filter fitting recess.

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