JP3355201B2 - Catalyst holding device in down-flow type catalyst packed tower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic catalytic reforming reaction tower in petroleum refining, an ammonia synthesis tower in an ammonia production plant, and a catalyst used in downflow, upper flow and horizontal flow type catalyst packed towers used in chemical processes and the like. The present invention relates to a holding method and an apparatus.

[0002]

2. Description of the Related Art In a catalytic reforming reaction tower in a petroleum refining plant or an ammonia synthesis tower in an ammonia production plant, when the flow of fluid takes a down-flow type or an upper-flow type, a conventional method for forming a catalyst layer in the column has been used. The following two approaches have been taken.

One method is shown in FIG. 17 as an example.
In order to form the first catalyst layer a and the second catalyst layer b, a catalyst holding material c is spread just below the catalyst layer,
The catalyst holding material c prevents the catalyst from flowing out together with the fluid. Further, another catalyst holding material d having a larger particle size is spread under the catalyst holding material c.
The lowermost part of the catalyst layer b is provided with a receiver e for supporting the catalyst layer and the catalyst holding material. The upper part of each catalyst layer is provided with a catalyst holding material f for keeping the level of the catalyst layer uniform. Are spread all over.

[0004] Thus, two catalyst layers a and b are formed. In the figure, k is a catalyst outlet and l is an intermediate liquid inlet. Generally, the fluid enters through the upper inlet g and is distributed over the entire surface by the distributor h.
After a certain catalytic reaction has taken place in the first catalytic layer a
And after the catalytic reaction has taken place, it is led out of the tower from the lower outlet i.

Another method is to directly support the catalysts of the respective layers a and b on the respective catalyst holding grids j as shown in FIG. In general, the structure of the catalyst holding grid j is such that a fine wire mesh is laid on the grid so that the catalyst does not flow out with the product, and the joint between the wire mesh and the rising portion to the tower wall is particularly carefully fixed with a wire. And so on. In addition, since such a fine wire mesh is weak in strength, it is a general structure that another strong wire mesh having a coarse mesh is laid between the wire mesh and the grid to compensate for the weakness.

In FIG. 18, the same components as those in FIG. 17 are denoted by the same reference numerals.

[0007]

In a down-flow type catalyst packed column, the reaction time between the fluid and the catalyst, that is, the distance of the fluid passing through the catalyst layer must be constantly constant in order to obtain a high-performance catalytic reaction. Generally, the thickness of the catalyst layer is large in the downflow type catalyst packed tower. The fluid is evenly distributed by the distributor over the cross section of the column before entering the catalyst layer and enters the entire surface of the catalyst layer. However, when passing through the catalyst layer having a large thickness, the fluid flows avoiding a closed portion or a clogged portion of the catalyst layer. Once such a drift occurs, the closed or clogged portion does not recover spontaneously, so caulking, that is, abnormal heat generation occurs at that portion. This abnormal heat generation not only degrades the performance of the contact reaction, but also occurs near the tower wall, catalyst holding wire mesh and grid,
In this device, since the catalyst is in direct contact with the tower wall, even the metal tower wall, wire mesh, and grid are damaged. That is, the tower wall, wire mesh, and grid that have come into contact with the high-temperature catalyst are deteriorated and their life is shortened.

In a down-flow type catalyst packed tower, it is necessary to inspect and repair the catalyst, the catalyst supporting wire mesh, and the grid after a certain period of operation. Since the conventional catalyst packing method has a single layer, the entire catalyst has to be drawn out of the column. In addition, it is necessary to refill all the catalysts extracted again after partial inspection and repair of the wire mesh and grid. In addition to the inconvenience that repair work must be carried out in the tower in principle, in the case of a plant, such periodic inspections are performed by shutting down all the plants at the same time. It takes a lot of manpower because it is only allowed.

[0009] Recharging after extracting all the catalyst as described above not only increases the labor and costs for the period, but also damages the expensive catalyst itself and deteriorates the quality of the catalyst. There is a fundamental drawback that adversely affects the performance of the reaction.

The present invention has been made in view of the problems of the above-described conventional method of holding a catalyst in a downflow type catalyst packed tower, and can promote a uniform flow of a fluid, Even if a heat generation phenomenon occurs, there is no risk of damaging the metal parts such as the tower wall, and the inspection and repair of the catalyst and the screen part can be performed in a short time at low cost, and there is no possibility that the catalyst will deteriorate. An object of the present invention is to provide a method and an apparatus for holding a catalyst in a down-flow type catalyst packed column.

[0011]

The downflow type catalyst holding apparatus of the present invention which achieves the above object has a cross section large enough to carry in and out from the opening of the downflow type catalyst packed tower, A plurality of catalyst containers each having a screen provided on the fluid inlet side and the fluid outlet side are filled with a filler such as a catalyst, and the plurality of catalyst containers are assembled in a downflow type catalyst packed tower.

According to the apparatus of the present invention, the fluid injected from the upper part of the catalyst packed tower enters the catalyst container through the screen on the fluid inlet side of each catalyst container, and after the catalytic reaction is performed, the fluid is injected from the screen on the fluid outlet side. Exit and move to the next step. Fillers such as catalyst are contained in each catalyst container and do not directly contact metal parts such as tower walls and receivers, so high-temperature reaction heat of the catalyst is not transmitted to metal parts such as tower walls. Absent.

[0013] The catalyst filling method for a downflow type catalyst packed tower according to the present invention, which achieves the above object, has a cross section large enough to be able to be loaded and unloaded from an opening of the downflow type catalyst packed tower. A catalyst is filled in a plurality of catalyst containers each provided with a screen on the inlet side and the fluid outlet side, and the plurality of catalyst containers are loaded into a downflow type catalyst packed tower and assembled to form a cylindrical catalyst layer. When the screen is inspected or repaired, only the catalyst container that needs to be inspected or repaired is carried out from the opening and inspected or repaired.

According to the method of the present invention, each catalyst container, which has been filled with a catalyst outside the catalyst packed tower in advance, is carried in from the opening of the catalyst packed tower and assembled in the tower. During operation, the fluid injected from the upper part of the catalyst packed tower enters the catalyst container from the screen on the fluid inlet side of each catalyst container, passes through the catalyst layer, exits from the screen on the fluid outlet side, and proceeds to the next step. When inspecting or repairing the screen, only the catalyst containers requiring inspection or repair are carried out of the tower for inspection and repair, and other catalyst containers are left installed in the tower.

The present invention can be applied not only to a down-flow (downflow) type catalyst packed column but also to an upper flow (upward flow) type catalyst packed column and a horizontal flow (horizontal flow) type catalyst packed column. Can be. Therefore, the term “downflow catalyst packed tower” in the claims is not limited to the usual meaning of “downflow catalyst packed tower” but also “upper flow catalyst packed tower” and “horizontal flow catalyst packed tower”. Is used as a special term representative of a broad concept that also includes.

The term "filler" described in the claims includes not only a catalyst in a narrow sense but also various fillers used in a chemical process such as activated carbon, ion exchange resin and filter material.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3 show one embodiment of a catalyst holding device in a downflow type catalyst packed tower according to the present invention. FIG. 1 is a vertical cross-sectional view schematically showing the inside of a downflow-type catalyst packed tower in which a catalyst container is loaded, FIG. 2 is a view taken along the line AA in FIG. 1, and FIG. 3 is a perspective view showing each catalyst container. FIG.

The catalyst packed column 1 is provided with a fluid (raw material) to be subjected to a catalytic reaction, a catalyst vessel charging inlet 2, a fluid (product) outlet 3 after the catalytic reaction, and upper and lower distributors 4 and 5. . Reference numeral 6 denotes an inlet for the fluid supplied to the distributor 5.

In the packed tower 1, an upper catalyst layer 9 and a lower catalyst layer 10 composed of a plurality of catalyst containers 8 are formed on two upper and lower catalyst container receivers 6 and 7, respectively.

The catalyst vessel 8 has a catalyst layer formed into a plurality of segments each having a cross section large enough to be loaded and unloaded from the inlet 2 of the catalyst packed tower 1 along the axial surface of the cylinder. A central catalyst container 8 having a square cross section shown in FIGS. 2 and 3A;
It comprises a peripheral catalyst container 8 'having an arc-shaped side surface 8'a along the inner periphery of the catalyst packed tower 1 shown in FIGS. An upper screen 11 is provided on the surface (top surface) on the fluid inlet side.
However, the lower screen 1 is provided on the surface (bottom surface) on the fluid outlet side.
2 are each stretched. Screens 11 and 12
A side plate 13 is provided on each side connecting the. As each of the screens 11 and 12, a known screen such as one obtained by welding a wedge wire to a support lot can be used.

As the catalyst container, as shown in FIG. 3C, a catalyst container 8 "provided with an intermediate screen 14 for supporting the catalyst in the middle can be used. Each of the catalyst containers 8, 8 ' , 8 ″, the upper screen 11 also serves as a lid and can be freely removed.
When the catalyst is filled in the catalyst container, the upper screen 11
Remove and perform.

In order to form a catalyst layer using this catalyst container, the catalyst is first filled in each of the catalyst containers 8 and 8 'outside the tower, and the upper screen 11 is closed. 8, 8 'are carried into the tower from the entrance 2 of the tower by a method such as being suspended by a crane or the like, and are placed at predetermined positions on the container receivers 6, 7. Side plates 1 of container receivers 6, 7 and catalyst containers 8, 8 '
It is preferable that a protrusion is provided on one of the lower edges of the third member and a recess is provided on the other, and the lower edge is fitted. The adjacent catalyst containers 8 and 8 'are arranged without any gap so that the side plates 13 are in contact with each other. Or, use a packing to arrange so as to eliminate the gap. In this manner, the plurality of catalyst containers 8, so that the shape after assembly becomes one catalyst layer as a whole,
By assembling 8 'in the tower, each catalyst layer 9, 10 is formed.

During operation, the fluid injected from the inlet 2 of the catalyst packed tower 1 is supplied through the distributor 4 to each of the catalyst vessels 8 of the upper catalyst layer 9 arranged in a cylindrical shape as a whole.
After entering the catalyst containers 8 and 8 'in the direction of the arrow from the screen 11 on the fluid inlet side of 8' and passing through the catalyst layer 9 having a uniform thickness, a contact reaction with the catalyst is performed. It flows out through the screen 12 on the outlet side and enters the respective catalyst containers 8, 8 ′ of the lower catalyst layer 10 via the receiver 6 and the distributor 5. Here, after the contact reaction with the catalyst is performed, the fluid is guided to the outside of the tower from the fluid outlet 3 of the tower via the receiver 7.

The screens 11, 12 of the catalyst containers 8, 8 '
When inspection or repair is required,
Alternatively, only the plurality of catalyst containers 8, 8 'are lifted by a crane or the like, carried out of the tower, and after performing necessary inspection and repair, returned to the original position in the tower. The other catalyst containers 8, 8 'are left installed in the tower.

FIGS. 4 and 5 show another embodiment of the apparatus of the present invention. In this embodiment and other embodiments described below, the same components as those in the embodiment of FIG. 2 are denoted by the same reference numerals, and detailed description will be omitted. FIG. 4 is a view similar to FIG. 2 showing a cross section of the packed tower 1, and FIG. 5 is a perspective view showing a catalyst container.

In this embodiment, the central catalyst container 2
5 has an equilateral triangular cross section as shown in FIG. 5 (a), and the peripheral catalyst container 20 'has an arcuate side surface along the inner periphery of the catalyst packed tower 1 as shown in FIG. 5 (b). It has a cross-sectional shape having 20'a. Other configurations are the same as those of the catalyst container of FIGS.

6 to 8 show another embodiment of the apparatus of the present invention. FIG. 6 is a view similar to FIG.
FIG. 7 is a perspective view showing a catalyst container, and FIG. 8 is a plan view of a baffle plate.

In this embodiment, the cylindrical catalyst containers 30 shown in FIG. 7 are arranged adjacent to each other as shown in FIG. In this case, a gap 31 is formed between the catalyst containers 30. When the fluid flows down from the distributors 4 and 5 in this state, part of the fluid
Fall through the gap 31 without passing through the inside. In order to prevent this, a disk-shaped baffle plate 32 shown in FIG.
Use The baffle plate 32 is arranged above the catalyst layer after assembling the plurality of catalyst containers 30 into one catalyst layer, and the screen 1 on the fluid inlet side of each catalyst container 30 is provided.
A circular opening 33 is formed in a portion facing 1. Therefore, when the baffle plate 32 is installed after assembling the catalyst layer, the baffle plate 32 covers the space above each catalyst container 30 except for the portion facing the screen 11, and the fluid flowing down from the distributors 4, 5 is The fluid flows into the respective catalyst containers 30 from the screens 11 of the respective catalyst containers 30 through the openings 33 of the baffle plate 32, and the flow of the fluid into the gaps 31 can be prevented.

In FIGS. 1 to 8, each of the cylindrical catalyst containers is installed so as to be in close contact with each other, but on the contrary, each of the catalyst containers is installed so as to maintain a constant interval between the catalyst containers. A baffle plate is provided at the upper and lower portions of each catalyst container except for portions facing the fluid inlet and outlet screens, so that the space outside the side plate of each of these catalyst containers is formed as a closed space. You may. Originally, the main purpose of a catalyst packed tower was to cause the fluid that entered from the top to contact the catalyst in the catalyst vessel, but the reaction temperature gradually increased as the fluid flowed down in the catalyst layer, and eventually the reaction started. It is necessary to cool the high temperature in the packed tower because it may reach an undesirably high temperature or high enough to endanger the packed tower itself.

In the closed space formed as described above, it is possible to control the ideal temperature in the packed tower by filling a cooling fluid for cooling or circulating the cooling fluid by connecting a pipe to the outside provided in the closed space. Will be possible.

9 to 11 show another embodiment of the present invention. 9 is a longitudinal sectional view showing a state in which a catalyst container is assembled in the catalyst packed tower 1, FIG. 10 is a view taken along the line BB of FIG. 9, and FIG. 11 is a perspective view of the catalyst container. In this embodiment, the catalyst container 40 has a shape in which the catalyst layer is divided radially along an axial surface and along a surface orthogonal to the axial direction. The catalyst container 40 'in FIG.
1, a lower screen 12 and an intermediate screen 14 are provided.

FIGS. 12 to 14 show another embodiment of the apparatus of the present invention. FIG. 12 is a view similar to FIG. 2 showing a cross section of the packed tower 1, FIG. 13 is a perspective view showing a catalyst container, and FIG. 14 is a sectional view showing a flow of a fluid in the apparatus of the present embodiment.

In this embodiment, the catalyst container 50 has a rectangular cylindrical inner screen tube 5 having screens on all four sides.
The outer screen cylinder 50b has a rectangular tubular shape having screens on four sides having a diameter larger than 0a.

The two screen cylinders 50a and 50b are connected to the bottom plate 50.
They are interconnected by c. Inner screen tube 50
a between the outer screen cylinder 50b and the outer screen cylinder 50b
0d is formed, and the gap d is filled with the catalyst. A cover plate 50e that covers the gap d is provided. A central space 5 is provided inside the inner screen tube 50a.
0f is formed.

As shown in FIG. 12, a plurality of the above-described catalyst containers 50 are arranged at intervals from each other, and a baffle plate 51 (FIG. 14) is arranged thereon. The baffle plate 51 has a disk shape and an opening 51a is formed in a portion facing the central space 50f of each catalyst container.

When fluid flows down from the distributors 4 and 5 in this state, the fluid flows through the openings 51 of the baffle plate 51.
It flows down into the central space 50f of the catalyst container 50 via a. Since the lower portion of the catalyst container 50 is closed by the bottom plate 50c, the fluid fills the central space 50f, and FIG.
As shown by the middle arrow, the gap 5
0d and after performing a catalytic reaction, the outer screen cylinder 50b
Spill out of. By configuring the catalyst container 50 in this manner, the area of the fluid flowing into the catalyst layer is increased, and the efficiency of the catalytic reaction is increased.

FIGS. 15 and 16 show still another embodiment of the present invention. FIG. 15 is a view similar to FIG. 2 showing a cross section of the packed tower 1, and FIG. 16 is a perspective view showing a catalyst container.

This embodiment is a modification of the embodiment shown in FIGS. 12 to 14, in which a catalyst container 60 has a cylindrical inner screen cylinder 60.
a and an outer screen cylinder 60b, and has the same configuration as the embodiment of FIGS.

FIGS. 19 and 20 show a case where a space 70 is provided between each stage of the upper and lower catalyst containers of the embodiment of FIGS. 9 to 11 and a distributor pipe 72 or the like is provided above the catalyst container 40 in this space. An embodiment in which distributors are arranged is shown.

When a distributor in which a distributor is provided on the upper part of each catalyst vessel is installed in a packed tower, a multi-stage catalyst layer is formed in the packed tower, and each catalyst layer is provided with a distributor on the upper part thereof. Fluid can be supplied or collected uniformly for each layer.

In such a catalyst packed column, the fluid supplied from the top can produce a product fluid in which the contact reaction is carried out in an arbitrary stage.

Further, if necessary, the raw material fluid can be supplied from the intermediate stage. The distributor may include not only the distributor pipe 72 but also an attached structure such as a baffle plate for more uniformly and smoothly inflow and outflow of the fluid.

The screen wire used in each of the above embodiments is not limited to a wedge wire, but may be a square, circular or other cross-sectional shape. The screen is not limited to a screen using a wire, and other types of screens such as a wire mesh, a perforated plate, and the like may be used. The catalyst packed tower includes not only a cylinder but also a square tube (polygonal tube). The filler used is not limited to one type, and two or more types of fillers can be used simultaneously.

[0044]

As described above, according to the present invention, the following effects are produced by the structure of the catalyst holding device and the method described in the claims. (1) Adjacent catalyst containers are completely sealed by side plates, or screens on side surfaces of adjacent catalyst containers serve as barriers even if no side plates are provided.
Fluid drift or bypass does not occur because the movement of fluid from one catalyst vessel to another is limited. The fluid flows as a regular flow in the catalyst container regulated by the side plate or the like, and realizes a high-performance contact reaction.

(2) Even if there is a clogged portion of the catalyst in the catalyst container and the fluid does not pass through this portion and abnormal heat generation occurs, the catalyst is directly transferred to metal parts such as the tower wall and the receiver. Since there is no contact, the tower walls and the like are not damaged by the high-temperature reaction heat of the catalyst. Therefore, in this case, it is only necessary to replace only the catalyst container in which abnormal heat generation has occurred,
The life of the reaction tower and the receiver can be extended.

(3) At the time of the periodic inspection, there is no need to remove all the catalyst to the outside of the tower in order to inspect the screen portion, and take out only the individual catalyst containers that need to be inspected outside the tower. In addition, the inspection itself is different from the conventional case, and the inspection can be performed without removing the catalyst from the catalyst container. When the screen portion of the catalyst container needs repair, the catalyst can be removed only from that catalyst container, repaired, and refilled again with a simple operation and days.

Further, if a spare catalyst container is prepared before the periodic inspection and replaced with a catalyst container requiring an inspection, the plant can be restarted extremely quickly.

(4) According to the method of the present invention, the initial catalyst filling operation before the operation is a small amount of catalyst filling operation for each catalyst container, so that the catalyst is not damaged and the packing density can be easily adjusted. Having. In the conventional method, when the catalyst is charged before the operation, the operation becomes large, so that some of the catalyst is charged in a damaged state.

At the time of periodic inspection, there is a remarkable difference in the method of handling the catalyst between the conventional method and the present invention as described above, and according to the present invention, the catalyst is hardly damaged during the inspection.

Therefore, according to the present invention, compared with the conventional method,
In addition to being able to form a uniform catalyst layer, it has an epoch-making effect of preventing deterioration of the catalyst quality and greatly improving the performance of the catalytic reaction itself by the catalyst.

(5) Further, according to the present invention, it is possible to install a packed tower in a horizontal direction and to replace a downflow or an upper flow with a horizontal flow, which is impossible with the conventional method. Will be possible.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the device according to the invention,
It is a longitudinal cross-sectional view which shows typically the inside of the down flow type catalyst packed tower in which the catalyst container was inserted.

FIG. 2 is a view taken in the direction of arrows AA in FIG. 1;

FIG. 3 is a perspective view showing individual catalyst containers.

FIG. 4 shows another embodiment of the apparatus according to the present invention, and is a cross sectional view of a packed tower.

FIG. 5 is a perspective view showing a catalyst container used in the present embodiment.

FIG. 6 shows another embodiment of the apparatus according to the present invention, and is a cross-sectional view of a packed tower.

FIG. 7 is a perspective view showing a catalyst container used in the present embodiment.

FIG. 8 is a plan view of a baffle plate used in the present embodiment.

FIG. 9 shows another embodiment of the apparatus according to the present invention, and is a longitudinal sectional view showing a state where a catalyst container is assembled in a catalyst packed tower.

FIG. 10 is a view taken in the direction of arrows BB in FIG. 9;

FIG. 11 is a perspective view of a catalyst container used in the present embodiment.

FIG. 12 shows another embodiment of the apparatus according to the present invention, and is a cross-sectional view of a packed tower.

FIG. 13 is a perspective view of a catalyst container used in the present embodiment.

FIG. 14 is a sectional view showing a state of a flow of a fluid in the embodiment.

FIG. 15 is a cross-sectional view of a packed tower, showing still another embodiment of the apparatus according to the present invention.

FIG. 16 is a perspective view of a catalyst container used in the present embodiment.

FIG. 17 is a longitudinal sectional view showing an example of a conventional downflow type catalyst packed tower.

FIG. 18 is a longitudinal sectional view showing another example of the conventional downflow type catalyst packed tower.

FIG. 19 shows another embodiment of the present invention, and is a vertical sectional view of a packed tower.

FIG. 20 is a perspective view of a catalyst container used in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Catalyst packed tower 2, 3 Opening 8 Catalyst container

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI C10G 45/00 C10G 45/00 (58) Field surveyed (Int.Cl. ⁷ , DB name) B01J 8/00-8/06 C01C 1/04 C10G 31/00 C10G 45/00

Claims (2)

(57) [Claims] 1. A cylindrical shape and the axis of the cylinder is vertical.
Are installed to, carried in from the opening of the down flow type catalyst packed column has a cross-section of the discharge is large enough to, a plurality of catalyst containers provided with a screen, respectively to the fluid inlet side and fluid outlet side In a catalyst holding device in which a plurality of catalyst containers are packed in a down-flow type catalyst packed tower, the upper portion provided in the upper opening portion of the catalyst container is filled.
The screen constitutes the fluid inlet side screen, and
The lower screen provided at the lower opening of the medium container is
It constitutes a screen of a fluid outlet side, holding a predetermined distance in the catalyst container between <br/> adjacent, a space formed between the catalyst container and closed space, cooling water, etc. catalyst container to the closed space A catalyst holding device in a downflow type catalyst packed tower, wherein a material having a function different from that of a filler in the inside is filled. 2. A plurality of catalyst containers having a cross section large enough to be able to be loaded and unloaded from the opening of the down-flow type catalyst packed tower and having screens on the fluid inlet side and the fluid outlet side, respectively. In a catalyst holding device in which the plurality of catalyst containers are assembled in a down-flow type catalyst packed tower, the catalyst containers are each arranged such that the axis of the cylinder is vertical.
The inner screen cylinder is formed as a double cylinder consisting of an inner screen cylinder and an outer screen cylinder, the peripheral surface of the inner screen cylinder constituting the fluid inlet side screen, and the peripheral surface of the outer screen cylinder being the fluid outlet. Make up side screen, front
The lower opening of the catalyst container as a double cylinder is
While closing, the plurality of catalyst containers are assembled to form one
Only the upper opening of each inner screen cylinder when used as a catalyst layer
The baffle plate that communicates with the upper
A catalyst holding device in a downflow type catalyst packed tower provided so as to cover a portion .