JP2001070805A - Plate type catalyst structure and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate type catalyst structure capable of preventing the pressure drop of the catalyst structure as a whole from being increased by reducing an undesirable influence, caused even when the laminated intervals between mutual catalyst elements are changed a little to a minimum and achieving satisfactory catalyst efficiency. SOLUTION: This catalyst structure is formed by laminating such many catalyst elements 1 and housing them in a frame body 3, as are obtained by bending rectangular or square flat plates with a catalyst component deposited on the surfaces at prescribed intervals in the perpendicular direction with respect to a pair of the sides of the flat plate to alternately form planar parts and stepped parts or by curving the flat plates in corrugated forms at prescribed intervals in the perpendicular direction with respect to the pair of the sides to form mountain parts and valley parts alternately. In such a catalyst structure, one or more flat plate-shaped catalyst elements 2 are interposed between the mutual elements 1 of the stepped form or the corrugated form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate-like catalyst structure and a method for producing the same, and more particularly, to a plate-like catalyst structure capable of avoiding an increase in pressure loss and exhibiting sufficient catalytic activity and a plate-like catalyst structure. It relates to a manufacturing method.

[0002]

2. Description of the Related Art A plate-like catalyst is prepared by rolling a paste-like catalyst material on a catalyst base material and applying the same to a pair of forming rollers heated to a predetermined temperature and alternately in opposite directions. It is manufactured by bending or alternately forming peaks and valleys and forming steps or corrugations. In other words, in the production process of the plate-like catalyst, the plate-like catalyst as a product is devised so as to have a shape suitable for stacking at a constant interval (pitch), and the moisture of the catalyst-coated body is evaporated. Higher strength is achieved so as to withstand lamination. A plate-like catalyst (hereinafter, referred to as a catalyst element) formed in a stepped or corrugated shape is, for example, shown in FIG.
As shown in FIG. 7, a large number of the catalyst units are stacked and housed in the frame body 3 to form a catalyst unit. The catalyst unit is fired to form a plate-shaped catalyst structure.

However, in the above prior art, as shown in FIGS. 8 and 9, when the stepped portions are not sufficiently overlapped when the step-like catalyst elements 1 are stacked, sufficient strength in the vertical direction can be obtained. And the stacking height may not be uniform. Since the portion where the strength is insufficient or its peripheral portion is susceptible to a load, the deformation amount of each catalyst element is added with the increase in the number of stacked layers.
As shown in (1), there has been a problem that the entire catalyst laminate is greatly deformed, and a portion where the reaction gas blows through and a portion where the reaction gas stays are generated. In particular, there is a tendency that the amount of deformation of the catalyst element with respect to a certain load is increased by reducing the thickness of the catalyst element and increasing the number of stacks per unit based on the recent demand for downsizing of the catalyst device. The problem that the laminate is deformed is more evident than before.

In response to demands for downsizing the catalyst device, narrowing the pitch of the catalyst, and further improving the activity of the catalyst, the thickness of the catalyst is made thinner, and the lamination interval of the flat plate portion is made narrower. Proposals have been made to increase the contact efficiency with the reaction gas. FIG. 7 is an explanatory view showing an unknown catalyst structure by the present inventors. In FIG. 7, this catalyst structure is formed by laminating a large number of step-like catalyst elements 1 via a network 4, and the reaction gas flow is agitated by the network 4 to improve the catalyst efficiency. . This prior art discloses a network 4 arranged between catalytic elements 1.
Has the advantage that the degree of agitation of the gas to be treated can be controlled by the shape, but leaves room for further improvement in the catalyst efficiency.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and the prior art. A plate-shaped catalyst structure capable of exhibiting a sufficient catalyst efficiency while suppressing an increase in pressure loss as a whole of the catalyst structure by minimizing the influence of a change in the stacking interval between them, and a method for producing the same Is to provide.

[0006]

Means for Solving the Problems To solve the above problems, the invention claimed in the present application is as follows. (1) A catalytic element in which a rectangular or square flat plate having a catalyst component supported on its surface is bent stepwise at predetermined intervals in a direction parallel to a pair of sides thereof to form a flat portion and a step portion alternately. Or a catalyst in which the flat plate is curved in a corrugated shape at predetermined intervals in a direction parallel to a pair of sides thereof, and a plurality of catalyst elements in which peaks and valleys are alternately formed are stacked and housed in a frame. A plate-like catalyst structure, wherein a plate-like catalyst element is interposed at one or more places between the step-like or corrugated catalyst elements in the structure.

(2) A frame formed by laminating a large number of the step-like or corrugated catalyst elements described in the above (1) via a metal, ceramics or glass mesh having a large number of through holes penetrating on the front and back sides. A plate-shaped catalyst structure housed in a body, wherein a plate-shaped catalyst element is used instead of at least one of the meshes.

(3) The fixing device according to (1) or (2), wherein fixing means for supporting the flat catalyst element is provided at a contact portion of the frame with the flat catalyst element. Plate-like catalyst structure. (4) The plate-like catalyst according to any one of the above (1) to (3), wherein the laminating direction of the step-like or corrugated catalyst element is changed with the plate-like catalyst element interposed therebetween. Structure.

(5) In the method for manufacturing a catalyst structure according to the above (1), wherein a large number of step-shaped or corrugated catalyst elements are stacked and housed in a frame, the step-shaped or corrugated catalyst element is provided. After stacking a predetermined number of the flat catalyst elements, a predetermined number of the step-shaped or corrugated catalyst elements are further stacked on the flat catalyst element, and the flat catalyst elements are stacked in the step-shaped or corrugated shape. A method of manufacturing a plate-shaped catalyst structure, comprising: forming a catalyst laminate interposed at least at one position between the catalyst elements, and storing the catalyst laminate in a frame.

(6) The method for producing a plate-shaped catalyst structure according to the above (5), wherein the frame having a means for fixing the plate-shaped catalyst element is used. (7) The production of the plate-like catalyst structure according to the above (5) or (6), wherein the laminating direction of the step-like or corrugated catalyst element is changed with the plate-like catalyst element interposed therebetween. Method.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the drawings. FIG. 1 shows a step-like catalyst element (a) and a plate-like catalyst element (b) according to one embodiment of the present invention.
FIG. 3 is an explanatory view showing a catalyst structure (c). This catalyst structure was formed by alternately forming a flat portion and a step portion by bending a rectangular flat plate having a catalyst component supported on its surface in a stepwise manner at predetermined intervals in a direction parallel to the pair of sides, A plurality of step-like catalyst elements 1 are stacked and housed in a frame body 3, and two places between the step-like catalyst elements 1, for example, the number of stacks of the step-like catalyst elements 1 is every 50 sheets. The plate-shaped catalyst element 2 is interposed (a part of the catalyst element is not shown in the drawing. The same applies hereinafter).

According to the present embodiment, since the plate-like catalyst elements 2 are interposed every predetermined number of stacks of the step-like catalyst elements 1, distortion or deformation of the catalyst elements, or the mutual movement of the catalyst elements caused by the stacking of the catalyst elements. Since the gaps between the catalyst elements are dispersed without being added, no gap is formed between the uppermost step-shaped catalyst element 1 and the upper frame 3 of the catalyst laminate, and each catalyst element is spaced at a predetermined interval. And a plate-like catalyst structure laminated.

[0013] The plate-like catalyst structure of the present invention comprises a step-like or corrugated-like catalyst element laminate, in which plate-like catalyst elements are arranged between predetermined step-like or corrugated-like catalyst elements. Since all the distortions and deformations of the step-like or corrugated catalyst elements are not added and divided and dispersed, a uniform gas flow path is easily formed. The effect of dividing and dispersing distortions, etc., becomes more pronounced as the number of interposed flat catalyst elements increases, but if the number of flat catalyst elements is too large, a step-like or corrugated catalyst element and a flat catalyst element are interposed. The cross section of the formed gas flow path becomes triangular, so that the gas easily stays, and the pressure loss tends to increase. Therefore, in the present invention, it is preferable that the number of the plate-shaped catalyst elements used is minimized in order to secure the strength of the catalyst structure.

In the present invention, a plurality of step-like or corrugated catalyst elements are interposed at one or more locations between the stacked step-like or corrugated catalyst elements. It can be applied to catalyst structures. That is, by using a plate-shaped catalyst element instead of at least one of the meshes arranged between the catalyst elements, it is possible to suppress the occurrence of deformation, distortion, etc. of the entire catalyst structure and to improve the catalyst efficiency. it can. In this case, for the same reason as described above, it is preferable that the number of plate catalyst elements used is minimized.

In the present invention, it is preferable that a fixing means for supporting and fixing the plate-like catalyst element is provided at a place where the catalyst is accommodated, for example, a metal frame, where the plate-like catalyst element comes into contact. Thereby, the bending rigidity of the entire catalyst structure is further improved. As a means for fixing the plate-like catalyst element, for example, a method in which a projection is formed at a predetermined position on the inner wall surface of the frame using a press machine, or a projection is welded.

In the present invention, it is preferable to change the laminating direction of the step-like or corrugated catalyst element before and after the plate-like catalyst element interposed between the step-like or corrugated catalyst elements. As a result, the molding error and distortion of the step-like or corrugated catalyst element are dispersed without concentrating on one side of the plate-like catalyst element, so that the deformation or distortion of the entire catalyst structure can be minimized, and the pressure loss can be reduced. Is prevented, and the catalyst efficiency is further improved.

In the present invention, the step-like or corrugated catalyst element is prepared by rolling and applying, for example, a paste-like catalyst component to a metal, ceramics or glass catalyst base, and subjecting the same to a roll press, a flat press or the like. What machined and machined using it is used suitably. The molding and drying of the catalyst can be performed simultaneously by using a molding apparatus provided with a heating means. The plate-like catalyst element is preferably dried in advance to increase its rigidity, like the step-like or corrugated catalyst element. The rigidity can be further increased by using a catalyst substrate which is thicker than a substrate used when preparing a stepwise or corrugated catalyst as a catalyst substrate when preparing a plate-shaped catalyst element.

[0018]

Next, specific examples of the present invention will be described. Example 1 1400 twisted yarns of E glass fiber having a fiber diameter of 9 μm
Book / 40% titania, 20% silica sol, polyvinyl alcohol 1
% Of the slurry, and dried at 150 ° C. to give rigidity to obtain a catalyst substrate.

On the other hand, a specific surface area of about 270 m
² / g ammonium molybdate titanium oxide 1.2kg of _{((NH 4) 6 · Mo} 7 O 24 · 4H 2 O) 0.2
5 kg, 0.23 kg of ammonium metavanadate, 0.3 kg of oxalic acid, and 20 wt% silica sol
8 wt% of O ₂ was added, and the mixture was kneaded while adding water to form a paste. To this paste was added 15 wt% of kaolin-based inorganic fiber (trade name: kao wool) and further kneaded to obtain a catalyst paste having a water content of 30.5%.

The obtained catalyst paste is placed between the two previously prepared catalyst base materials, and is applied to the mesh and the mesh surface thereof with a pair of rolling rollers to form a 0.7 mm-thick plate-shaped catalyst-coated body. I got The obtained catalyst coated body is sandwiched between heating molds,
While drying, a stepped portion having a flat portion having a long side (length) of L = 15 mm and a step portion having a short side (height) of 4 mm alternately was formed, and cut into 450 mm square to obtain a stepped catalyst element. . The number of bent portions per one catalyst element was 29 or 30. On the other hand, after drying the plate-shaped catalyst-coated body, it was cut into 450 mm square to obtain a plate-shaped catalyst element.

As shown in FIG. 1C, each of the obtained step-like catalyst elements 1 has a stepped portion of 3 m.
m, and one plate-like catalyst element 2 is arranged for every 50 sheets to obtain a catalyst laminate consisting of 150 step-like catalyst elements as a whole with two plate-like catalyst elements interposed. The internal dimensions are 450 width
It was housed in a frame 3 having a height of 450 mm, a height of 450 mm and a depth of 450 mm, and was fired to obtain a catalyst structure.

Example 2 As shown in FIG. 2 (b), the step-like catalyst element 1 used in Example 1 was replaced with a rigid, 450 mm square mesh used as a catalyst substrate in Example 1. A large number are stacked via the object 4 ((a) of FIG. 2),
Instead of the second reticulated material 4, the flat catalyst element 2 used in Example 1 was arranged to form a catalyst laminate, which was housed in the same frame 3 as in Example 1 and calcined to form a catalyst structure. I got The number of step-like catalyst elements used was 122 and the number of meshes was 120.

Example 3 As shown in FIG. 3, above and below a flat catalyst element 2,
A catalyst structure was obtained in the same manner as in Example 1 except that the stepwise catalyst elements 1 were stacked so that the direction of the stepwise catalyst elements 1 was reversed in the horizontal direction. Example 4 As shown in FIG.
A catalyst structure was obtained in the same manner as in Example 1 except that the step-like catalyst elements 1 were stacked such that the directions of the step-like catalyst elements 1 were inverted in the vertical and horizontal directions.

Embodiment 5 As shown in FIG. 5, the plate-shaped catalyst element 2 is fixed by using a frame having a concave and convex portion as fixing means 5 at a contact portion with the plate-shaped catalyst element 2 as the frame 3. Except that, a catalyst structure was obtained in the same manner as in Example 1 above. The number of stacked catalyst elements was the same as in Example 1. Comparative Example 1 The step-like catalyst element 1 used in Example 1 was simply laminated according to the conventional technique as shown in FIG. 6 to obtain a catalyst structure.

Comparative Example 2 As shown in FIG. 7, a catalyst structure was obtained in the same manner as in Example 2 except that the flat catalyst element 2 was not used.
Regarding the catalyst structures of Examples 1 to 5 and Comparative Examples 1 and 2, between the top of the stepped portion of the uppermost stepped catalyst element 1, which should originally contact the frame 3, and the inner wall surface of the frame 3. When the generated voids were evaluated, Examples 1 to 6 had no voids and were in contact with each other, whereas Comparative Example 1 had five voids and Comparative Example 2 had four voids. From this, in Examples 1 to 5, the distance between the catalysts was kept constant,
It can be seen that no distortion or deformation occurred in the entire catalyst structure.

[0026]

According to the invention described in claim 1 of the present application,
Since the amount of deformation of the stepped or corrugated catalyst elements or the gaps between the elements caused by the stacking of the catalyst elements are dispersed, each of the catalyst elements is stacked at regular intervals and has a uniform gas flow path. It becomes a catalyst structure. Therefore, an increase in pressure loss can be avoided, and sufficient catalyst performance can be ensured.

According to the invention described in claim 2 of the present application, it is possible to prevent deformation of the entire catalyst laminate and improve catalyst efficiency. According to the invention described in claim 3 of the present application, in addition to the effects of the above-described invention, the effect of dispersing the amount of deformation of the catalyst elements or the gap between the elements caused by the stacking of the catalyst elements is further improved.

According to the invention described in claim 4 of the present application, in addition to the effects of the above invention, the effect of dispersing the amount of deformation of the catalyst elements or the voids generated between the catalyst elements is further improved. According to the invention described in claim 5 of the present application, the amount of deformation of the catalyst element or the gap between the elements caused by the stacking of the catalyst element is dispersed,
A plate-like catalyst structure in which the catalyst elements are stacked at regular intervals is obtained.

According to the invention described in claim 6 of the present application, in addition to the effects of the above invention, the amount of deformation of the catalyst element or the effect of dispersing the gap between the elements is further improved. According to the invention described in claim 7 of the present application, in addition to the effects of the above invention, the amount of deformation of the catalyst element or the effect of dispersing the voids generated between the elements is further improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a catalyst structure, a step-like catalyst element, and a plate-like catalyst element according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a catalyst structure and a network showing another embodiment of the present invention.

FIG. 3 is an explanatory view showing another embodiment of the present invention.

FIG. 4 is an explanatory view showing another embodiment of the present invention.

FIG. 5 is an explanatory view showing still another embodiment of the present invention.

FIG. 6 is an explanatory diagram of a conventional technique.

FIG. 7 is an explanatory diagram of the prior art.

FIG. 8 is an explanatory diagram showing a problem of the related art.

FIG. 9 is a partially enlarged view of FIG. 8;

FIG. 10 is an explanatory diagram showing a problem of the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Step catalyst element, 2 ... Flat catalyst element, 3 ... Frame, 4 ... Net, 5 ... Flat catalyst element fixing means.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Eiji Miyamoto Inventor 3-36 Takara-cho, Kure-shi, Hiroshima Babcock Hitachi Kure Research Laboratory F-term (reference) 4G069 AA03 AA08 AA11 CA02 DA06 EA21 ED10 EE06

Claims (7)

[Claims] 1. A catalyst in which a flat or stepped portion is formed alternately by bending a rectangular or square plate having a catalyst component supported on its surface in a stepwise manner at predetermined intervals in a direction parallel to a pair of sides thereof. The element or the flat plate was bent into a corrugated shape at predetermined intervals in a direction parallel to a pair of sides thereof, and a large number of catalyst elements in which peaks and valleys were alternately formed were stacked and housed in the frame. A plate-like catalyst structure, wherein a plate-like catalyst element is interposed at one or more positions between the step-like or corrugated catalyst elements. 2. The step-like or corrugated catalyst element according to claim 1 is laminated in large numbers via a metal, ceramics or glass mesh having a large number of through-holes penetrating on the front and back sides, and is stacked in a frame. In the stored plate-like catalyst structure,
A plate-like catalyst structure, wherein a plate-like catalyst element is used instead of at least one of the meshes. 3. The plate-shaped catalyst structure according to claim 1, wherein fixing means for supporting the plate-shaped catalyst element is provided at a contact portion of the frame with the plate-shaped catalyst element. body. 4. The plate-like catalyst structure according to claim 1, wherein the laminating direction of the step-like or corrugated catalyst elements is changed with the plate-like catalyst element interposed therebetween. . 5. The method for manufacturing a catalyst structure according to claim 1, wherein a plurality of step-shaped or corrugated catalyst elements are stacked and housed in a frame. After laminating the plate-like catalyst elements, a predetermined number of the step-like or corrugated catalyst elements are further laminated on the plate-like catalyst element, and the plate-like catalyst elements are formed in the step-like or corrugated form. A method for manufacturing a plate-shaped catalyst structure, comprising: forming a catalyst laminate interposed at least at one position between catalyst elements, and storing the catalyst laminate in a frame. 6. The method for producing a plate-like catalyst structure according to claim 5, wherein a member having a means for fixing the plate-like catalyst element is used as the frame. 7. The method for producing a plate-like catalyst structure according to claim 5, wherein the laminating direction of the step-like or corrugated catalyst elements is changed with the plate-like catalyst element interposed therebetween. .