JP3757305B2 - Modular catalyst - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is, for example, a catalyst for catalytic reduction of nitrogen oxide (NOx) or a honeycomb-shaped catalyst used as a NOx absorption / removal agent, and more specifically, alternately arranged flat plates and corrugated plates. The present invention relates to a modularized catalyst in which a large number of catalytic elements in which a catalytic metal is supported on a carrier having a flat plate / corrugated multilayer structure is accommodated in a storage frame, and the catalyst is modularized to facilitate handling.
[0002]
[Prior art]
As this type of modularized catalyst, for example, as disclosed in JP-A-6-269679, a catalyst group in which a plurality of catalyst elements are arranged adjacent to each other and in contact with each other, and a catalyst, A vertical cylindrical frame wall that surrounds the group from the surroundings and a storage frame that has a grid-like retainer for preventing catalyst dropout located below the catalyst group.The catalyst element can be dropped at room temperature by tightening the frame wall. What is known to be able to stop is known.
[0003]
[Problems to be solved by the invention]
At the time of exhaust gas purification, the temperature of the modular catalyst becomes a high temperature of 400 ° C. or higher. The catalytic element is made of ceramic paper and the storage frame is made of steel. Compared to the thermal expansion coefficient of ceramic paper, the thermal expansion coefficient of steel is much higher. For this reason, during purification of exhaust gas, the modular catalyst hardly thermally expands, but the storage frame expands greatly and the tightening force by the frame wall decreases. As a result, the catalytic element slips off due to the vibration of the operating equipment and the fluid vibration, the retainer and the catalytic element come into contact with each other, and the abrasion of the catalytic element occurs.
[0004]
An object of the present invention is to provide a modularized catalyst that can prevent wear and abrasion of a catalyst element.
[0005]
[Means for Solving the Problems]
The modular catalyst according to the present invention is located below a catalyst group in which a plurality of catalyst elements are arranged adjacent to each other and in contact with each other, a vertical cylindrical frame wall surrounding the catalyst group from the periphery, and the catalyst group. A modularized catalyst having a storage frame having a lattice retainer for preventing the catalyst from falling off, and capable of preventing the catalyst element from dropping at room temperature by tightening with a frame wall. There is a blocking means that can prevent the catalytic element from dropping due to thermal expansion, and the blocking means is constituted by a leaf spring provided upright on the retainer. And an elastic large protrusion is formed by cutting and raising the lower part of the leaf spring, and the upper part of the leaf spring is between the inner surface of the storage frame frame wall and the side surface of the catalyst element and / or The lower part of the leaf spring is located below the catalyst element, and the space between the inner surface of the storage frame frame and the side surface of the catalyst element is based on the thermal expansion of the storage frame when using the catalyst. And / or small protrusions are undulated along with a change in the gap between the side surfaces of adjacent catalyst elements .
[0006]
Since the modularized catalyst according to the present invention is provided with a blocking means that can prevent the catalytic element from dropping due to thermal expansion of the storage frame when the catalyst is used, there is no fear that the catalytic element slides down and the retainer and the catalytic element come into contact with each other. . Therefore, wear abrasion of the catalyst element can be prevented.
[0007]
Furthermore, in addition to preventing wear and tear of the catalyst element, the catalyst element is supported by the elastic force of the small protrusions even if a gap is generated between the side surfaces of adjacent catalyst elements, so the catalyst element does not have to worry about dropping. Even if the catalyst element falls, the falling catalyst element is received by the large protrusion, so that the catalyst element can be prevented from falling to the point where it comes into contact with the lower retainer.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0009]
Referring to FIG. 1 , the modularized catalyst includes a catalyst group 11, a housing frame 12 housing the catalyst group 11, and a ceramic wool buffer interposed between the outer surface of the catalyst group 11 and the inner surface of the housing frame 12. Material 34.
[0010]
The catalyst group 11 is composed of eight catalyst elements 21. The eight catalyst elements 21 are arranged in such a manner that four adjacent ones in the left-right direction and two in the front-rear direction (not shown) are in contact with adjacent ones.
[0011]
As shown in detail in FIG. 2, each catalyst element 21 is composed of a plurality of flat plates 24 and corrugated plates 25 that are alternately arranged, and a vertical rectangular cylindrical outer tube 22 that surrounds them. In addition, a catalyst metal is supported on a vertically long rectangular parallelepiped block. The flat plate 24, the corrugated plate 25, and the outer cylinder 22 are all made of ceramic paper.
[0012]
The storage frame 12 includes a rectangular vertical cylindrical frame wall 31 that is long on the left and right in the horizontal section, and upper and lower catalyst drop prevention retainers 32 and 33 that are provided at the upper and lower end openings of the frame wall 31, respectively. Both the frame wall 31 and the retainers 32 and 33 are made of steel.
[0013]
Although not shown, the frame wall 31 is connected to the four corners so as to be freely disengaged by hinges.
[0014]
The upper retainer 32 has a lattice shape, and includes a parallel vertical member 35 that extends in the left-right direction at the upper end opening of the frame wall 31, and a parallel cross member 36 that extends in the front-rear direction on the lower surface of the vertical member 35. And more. Similarly to the upper retainer 32, the lower retainer 33 has a lattice shape, and is provided with a parallel vertical member 37 that extends in the left-right direction at the lower end opening of the frame wall 31 and the front surface of the vertical member 37 in the front-rear direction. The parallel cross member 38 is made of.
[0015]
The tightening pressure adjusting spring plates 41 are provided upright at a plurality of appropriate positions on the upper surface of the lower retainer 33. The upper portions of some of the spring plates 41 are sandwiched between the inner surface of the buffer material 34 and the side surfaces of the catalyst element 21 opposite to the buffer material 34, and the upper portions of the remaining spring plates 41 are sandwiched between the side surfaces of the adjacent catalyst elements 21. .
[0016]
As shown in detail in FIG. 3, small elastic protrusions 42 are formed in a row in the upper part of the spring plate 41, and large elastic protrusions 43 are similarly arranged in a horizontal row in the lower part of the spring plate 41. It is formed side by side. The formation of the small protrusions 42 and the large protrusions 43 is caused by cutting and raising. The cutting and raising direction is reversed every other direction.
[0017]
When manufacturing a modularized catalyst, as shown in FIG. 4, with a portion having a small protrusion 42 of a spring plate 41 interposed between adjacent catalyst element 21 side surfaces (between the inner surface of the buffer material 34 and the catalyst element 21 side surfaces). In the same manner, the buffer material 34 is wound around the catalyst group 11, and the frame wall 31 from which one hinge is previously disconnected is wound and tightened from above, and the hinge that has been disconnected is connected. Then, the catalyst group 11 is fastened by the frame wall 31. As a result, the buffer material 34 is compressed, and the small protrusions 42 are tilted so that the adjacent catalyst elements 21 are substantially in contact with each other. In this state, the upper and lower retainers 32 and 33 are fixed to the frame wall 34 with rivets or bolts, and the catalyst group 11 is held in a tightened state by the frame wall 31. The catalyst group 11 is held in a floating state from the lower retainer 32 without dropping due to the tightening force of the frame wall 31. In this case, the elastic force to return the small protrusions 42 to the original standing posture acts against the tightening force of the frame wall 31, so the tightening force of the frame wall 31 is the conventional modularization described at the beginning. It may be smaller than the tightening force of the catalyst frame wall.
[0018]
When the modular catalyst is used, the modular catalyst is exposed to a high temperature state of 400 ° C. or higher, and the frame wall 31 is thermally expanded, but the catalytic element 21 is hardly thermally expanded. Is greater than the restoring displacement. Thereby, as shown in FIG. 5, a gap is generated between the side surfaces of the adjacent catalyst elements 21. Then, the small protrusion 42 rises by an amount corresponding to the generated gap, but the elastic force remains in the raised small protrusion 42, and the catalyst element 21 is supported by this elastic force. The catalyst element 21 does not have to worry about dropping. Even if the catalyst element 21 is dropped, the falling catalyst element 21 is received by the large protrusion 43, so the catalyst element 21 does not fall until it comes into contact with the lower retainer 33 (shown by a chain line in FIG. 5).
[0019]
When the use of the modular catalyst is interrupted, the temperature of the modular catalyst decreases to room temperature. Then, the frame wall 31 contracts, and the catalyst group 11 is tightened again by the frame wall 31, and the small protrusions 42 are tilted as shown in FIG. 4 so that the gap generated between the side surfaces of the adjacent catalyst elements 21 is eliminated. By the small projection 42 is brought down, excessive force is not applied to the catalyst element 21, there is no fear of damage to the catalytic element 21.
[0020]
【The invention's effect】
According to this invention, since there is no fear that the catalyst element slides down and the retainer and the catalyst element come into contact with each other, it is possible to prevent the catalyst element from being worn away.
[Brief description of the drawings]
FIG. 1 is a vertical longitudinal sectional view of a modular catalyst according to the present invention.
FIG. 2 is a perspective view of a catalyst element constituting the modular catalyst.
FIG. 3 is a perspective view showing details of a spring plate of the modular catalyst.
FIG. 4 is an explanatory view showing the operation of the spring plate.
FIG. 5 is an explanatory view showing another operation of the spring plate .
[Explanation of symbols]
11 Catalyst group
12 Storage frame
21 Catalytic element
31 Frame wall
33 Retainer
41 leaf spring
42 Protrusions
51 Compression coil spring

Claims (1)

A catalyst group 11 in which a plurality of catalyst elements 21 are arranged adjacent to each other and in contact with each other, a vertical cylindrical frame wall 31 surrounding the catalyst group 11 from the periphery, and a catalyst positioned below the catalyst group 11 In the modular catalyst that includes the storage frame 12 having the grid-like retainer 33 for preventing the drop-off, and is configured to prevent the catalyst element 21 from dropping at room temperature by tightening with the frame wall 31.
When the catalyst is used, the storage frame 12 has a blocking means that can prevent the catalyst element 21 from falling due to thermal expansion,
The blocking means is constituted by a plate spring 41 provided upright on the retainer 33. A small protrusion 42 is provided on the upper portion of the plate spring 41 by cutting up and a large elastic shape is provided on the lower portion of the plate spring 41. A protrusion 43 is provided by cutting and raising, and the upper portion of the leaf spring 41 is interposed between the inner surface of the storage frame frame wall 31 and the side surface of the catalyst element 21 and / or between the side surfaces of the adjacent catalyst element 21. The lower part is positioned below the catalyst element 21, and the space between the inner surface of the storage frame frame 31 and the side surface of the catalyst element 21 and / or the side surface of the adjacent catalyst element 21 based on the thermal expansion of the storage frame 12 when the catalyst is used. A modular catalyst in which the small protrusions 42 undulate with changes.

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