JPH0685866B2 - Catalytic reactor - 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 reactor,
In particular, the present invention relates to a catalytic reaction device that prevents catalyst destruction due to thermal expansion and thermal contraction of a reaction tube containing a catalyst.

[0002]

2. Description of the Related Art A reaction gas, which is provided with an outer cylinder and an inner cylinder, and in which a catalyst is sealed in a space formed by the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder, is passed through while heating to chemically react. A reformer for a fuel cell device is an example of a device that causes a reaction. This reformer introduces a mixed gas of natural gas and water vapor into the space, where it is heated from the outside by a burner to be a gas containing a large amount of hydrogen.

[0003]

In the reformer constructed as described above, the radial dimension (hereinafter referred to as a gap) of the space between the outer cylinder and the inner cylinder is determined when the device is started up (when the operation is started). ) And at the time of shutdown (at the time of stop), the size differs due to thermal expansion. Therefore, when the gap is expanded, the particles of the catalyst arranged in the space drop by its own weight so as to fill the gap created by the expansion of the gap. On the other hand, when the gap contracts, the catalyst particles are pushed upward, but at this time, a force such as a compressive force or a friction force that destroys the catalyst acts on the catalyst, which causes the device to start and stop. Over time, the catalyst is destroyed.

Regarding this phenomenon, Gas Research Insti
On Site Fuel Cell Power Plant Technolog by tute
y and Development Program, Anual Report (Jan 1982-Ja
n 1983) and argued as “slumping”. However, as a method for preventing this slumping, it has been proposed to provide a plurality of shelves for simply supporting the catalyst in the longitudinal direction of the space between the outer cylinder and the inner cylinder, but this method has However, it does not essentially prevent the movement of the catalyst due to stoppage, and does not essentially prevent the destruction of the catalyst.

Japanese Utility Model Laid-Open No. 58-137440 discloses a fuel cell reformer having an outer tube, an inner tube and a central tube, and a catalyst layer provided between the inner tube and the outer tube. However, the above publication does not discuss catalyst slamping or catalyst holding means. Also, Japanese Examined Japanese Patent Publication No. 50-32
In Japanese Patent Publication No. 67, as a means for holding the catalyst in the space between the inner cylinder and the outer cylinder, the support provided on the inner peripheral surface of the dish and the outer cylinder supporting the dish and the outer peripheral surface of the inner cylinder are disclosed. The use of a catalyst support means consisting of a support provided is described. However, even in the above publication, there is no description about the slumping of the catalyst, and the technique described in the publication is not sufficient for eliminating the slumping. By the way,
Outer cylinder with inner diameter of 100 mm and length of 1,600 mm, inner diameter of 30
A specific example of thermal expansion of an inner cylinder having a length of mm and a length of 1500 mm is 0.36 mm in the radial direction of the outer cylinder and 18 in the longitudinal direction.
It also has a thermal expansion of 1.2 mm in the inner cylinder diameter method and 19 mm in the longitudinal direction.

An object of the present invention is to suppress the destruction of the catalyst due to the expansion and contraction of the reaction tube caused by the reaction heat of the catalyst.

[0007]

SUMMARY OF THE INVENTION The above-mentioned problems are solved by a space formed by an inner cylinder, an outer cylinder concentrically arranged with the inner cylinder, an outer peripheral surface of the inner cylinder and an inner peripheral surface of the outer cylinder. A catalyst enclosed in a section, a catalyst holding means for holding the catalyst at the lower ends of the inner and outer cylinders, introducing a reaction target gas so as to pass through the catalyst, and a reaction gas that has passed through the catalyst, In a catalytic reaction device configured to be led out to the outside via the inner cylinder, the catalyst holding means, a plate portion, a first support means for holding the plate portion by the outer cylinder, and the inner cylinder are held. Second
The first support member is fixed to the inner peripheral surface of the outer cylinder, and the second support member is fixed to the outer peripheral surface of the inner cylinder, and the dish portion is fixed to the first and the second support members. It is achieved by placing the catalyst on the second support, arranging a plurality of reaction sections including the inner and outer cylinders in parallel, and accommodating these in a shell to form a catalytic reaction device.

The above object can also be achieved by a catalytic reaction device according to claim 1, wherein the inner cylinder and the outer cylinder are formed in a circular cross section.

Further, the above-mentioned problem is that one end of the outer cylinder is opened and the other end is closed, one end of the inner cylinder is connected to a means for leading out the reaction gas, and the other end is closed of the outer cylinder. It is also achieved by the catalytic reaction device according to the first aspect of the invention, which is opened near the portion.

[0010]

According to the present invention, the catalyst is accommodated between the inner cylinder and the outer cylinder, and the support of the catalyst holding means for supporting these catalysts is changed when the catalytic reactor is started and when it is lowered. is there. With this configuration, the compression force and frictional force applied to the catalyst can be reduced, and the destruction of the catalyst can be suppressed.

First, when the reformer is started up, the outer cylinder 1 thermally expands and then the inner cylinder 2 thermally expands. In this case, the outer cylinder 1
Even if the particles extend in the radial direction and the longitudinal direction, the second support 13 supports the plate 5 for holding the catalyst, and the catalyst does not move. Next, the eye plate 5 descends as the second support 13 descends,
Since the escape area for the catalyst 3 is created, it is possible to prevent the catalyst 3 from being crushed by compression due to the decrease in the distance between the inner cylinder and the outer cylinder due to expansion of the inner cylinder 2. The reason for this is, for example, contrary to the above, when it is configured to be supported by the first support 12 (second support 13
Is not present), the catalyst 3 comes down by its own weight by the volume increase in accordance with the thermal expansion of the outer cylinder 1. Then, when the inner cylinder 2 expands, the plate 5 does not move at this stage, and there is no escape place for the catalyst 3 that has descended by its own weight (the catalyst 3 has to be raised), resulting in compression failure of the catalyst 3. It becomes easy. On the other hand, if the second support 13 supports the perforation 5, the second support 13 also moves in the longitudinal direction as the inner cylinder 2 expands, so that the volume can be increased. Therefore, compression of the catalyst that has fallen under its own weight does not occur.

When the reformer is lowered, the outer cylinder 1 contracts first, and then the inner cylinder 2 contracts. Therefore, it is considered that the catalyst 3 rises while rubbing the tube walls of the inner and outer cylinders, and this friction energy is consumed for the destruction and deformation of the catalyst 3. In this case, the plate 5 is supported by the first support 12 and moves up, and moves while rubbing against the outer wall of the inner cylinder. The area of contact of the catalyst 3 is smaller on the outer wall of the inner cylinder than on the inner wall of the outer cylinder, and therefore the force applied to the catalyst by friction is small.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIGS. 1 and 2 show a reformer of a fuel cell device as an example of a catalytic reaction device. As shown in FIG. 1, the reformer has an inner cylinder 2 and an outer cylinder arranged concentrically with the inner cylinder 2. Reacting parts H1 to H7 composed of an annular portion formed by the outer peripheral surfaces of the cylinder 1 and the inner cylinder 2 and the inner peripheral surface of the outer cylinder 1, that is, a catalyst 3 enclosed in a space, and surrounding them. 6 arranged in the same manner, and reaction parts H1 to H7
The main parts are a burner 7 for heating and. The inner cylinder 2 and the outer cylinder 1 are circular in cross section, one end of the outer cylinder 1 is open and the other end is closed, and one end of the inner cylinder 2 is a conduit for leading out the reaction gas 9. 11, and the other end is opened near the closed end of the outer cylinder 1. The other end (lower end) of the inner cylinder is
It is arranged independently of the outer cylinder, and the lower end of the inner cylinder and the lower end of the outer cylinder are
It can move relatively independently in the axial direction. The reaction parts H1 to H7 are arranged side by side in the shell 6, and the conduit 11 is arranged in the shell 6 so as to gather one end of the inner cylinder 2 of each reaction part. Reference numeral 8 is a heat insulating material for the shell 6.

Further, in FIG. 1, reference numeral 5 denotes a perforation which holds the catalyst 3 at the lower ends of the outer cylinder 1 and the inner cylinder 2, and is supported by a support as shown in detail in FIG. As shown in FIG. 3, the perforated plate 5 is annular so as to fit in the space formed by the outer peripheral surface of the inner cylinder 2 and the inner peripheral surface of the outer cylinder 1, and has the following first and second support members. And formed independently. 12 and 13 are plate 5
Are first and second support bodies that support the outer cylinder 1 and the inner cylinder 2 at their lower end portions, and are formed annularly and independently of each other. The outer peripheral surface of the first support 12 is fixed to the inner peripheral surface of the outer cylinder 1, and the inner peripheral surface of the second support 13 is fixed to the outer peripheral surface of the inner cylinder 2. Further, the respective areas of the first and second supports 1 and 2 facing the lower surface of the plate 5 are configured to have a size such that the plate 5 can be independently moved. The eye plate 5 is placed on the upper surfaces of the supports 12 and 13,
13 and the plate 5 are not connected to each other, and when the plate 5 is moved upward, or when the plate 5 is held and the support is moved downward, the two are automatically separated. .

The reason why the plate 5 is supported by the first and second supports 12 and 13 is as follows. When the reformer is started up, the outer cylinder 1 thermally expands and then the inner cylinder 2 thermally expands. Therefore, in this case, if the second support 13 supports the plate 5, the catalyst 3 can be prevented from being compressed and broken. The reason for this is that, contrary to the above, for example, when the first support 12 is used to support the second support 13 (the second support 13 does not exist), the outer cylinder 1 moves in the radial and longitudinal directions. When extended, the catalyst 3 comes down by its own weight by the volume increase. Then, when the inner cylinder 2 expands, there is no escape place for the catalyst 3 that has descended due to its own weight (the catalyst 3 has to be raised), and the catalyst 3 is prone to compression fracture. On the other hand, if the second support 13 supports the perforation 5, the second support 13 also moves in the longitudinal direction as the inner cylinder 2 expands, so that the volume can be increased. Therefore, compression of the catalyst that has fallen under its own weight does not occur.

When the reformer is lowered, the outer cylinder 1 contracts first, and then the inner cylinder 2 contracts. Therefore, the catalyst 3 rises while rubbing the tube walls of the inner and outer cylinders. Since this friction energy is considered to be consumed for the destruction and deformation of the catalyst 3, in this case, it is better that the friction area is smaller.
The plate 5 is supported by the first support 12.

Returning to FIG. 1, in the reformer constructed as described above, the reaction gas 9 in which natural gas and water vapor are mixed is introduced into the space portion in which the catalyst 3 is sealed, and heated by the burner 7 here. While causing a steam reforming reaction,
It becomes a gas containing a large amount of hydrogen, passes through the inner peripheral surface of the inner cylinder 2, and is delivered to the outside of the shell 8 as a gas 10. Incidentally, FIG.
3 to 4, 4 is a radial dimension of the space between the outer cylinder 1 and the inner cylinder 2, that is, a gap.

Next, the operation of the embodiment constructed as described above will be described with reference to FIG. In FIG.
(A) is a diagram for explaining the state of one reaction section when the catalytic reactor, that is, when the reformer is stopped, (B) is at startup, (C) is at steady operation, and (D) is at shutdown. ,
(E) is a figure explaining the state at the time of a stop. The fifth
In the figure, the same parts as those in FIGS. 1 to 4 are designated by the same reference numerals.

First, in the state of FIG.
Are supported by the first and second supports 12 and 13.

Next, the state shown in FIG. 5B will be described. In this state, the inner cylinder 2 thermally expands after the outer cylinder 1 thermally expands, but the inner cylinder 2 extends in the longitudinal direction, so that the second support 13 supports the perforated plate 5,
The compression of the catalyst 3 due to the reduction of the gap 4 can be suppressed. After that, the apparatus enters a steady state, and the plate 5 is instructed by the first and second supports 12 and 13 (Fig. 5).
(State of (C)).

Next, the state of FIG. 5D will be described. In this state, the outer cylinder 1 contracts first and the inner cylinder 2 contracts later, but the perforation 5 is lifted upward by the first support 12. At this time, the catalyst 3 rises while rubbing the tube walls of the outer cylinder 1 and the inner cylinder 2. It is considered that this friction energy is consumed for destruction and deformation of the catalyst, but in this case, if the catalyst 3 is uniformly clogged, it is applied to the tube walls of the outer cylinder 1 and the inner cylinder 2 due to its own weight. The outer cylinder 1 and the inner cylinder 2 have the same force per unit area. Therefore, the frictional force F is expressed by F = μPS (where, μ: friction coefficient between the catalyst and the tube wall, P: force per unit area (average in height direction), S: frictional area), The catalyst 3 is the inner cylinder 2
Since it is moved along the outer wall of the catalyst 3, the frictional force is small and the destruction of the catalyst 3 is small. Then, when the apparatus is stopped, the state of FIG. 5 (E) is entered. In this case, FIG.
In the same manner as in the above state, the eye plate 5 has the first and second supports 12, 13
Supported by.

In the above embodiment, the outer cylinder and the inner cylinder are described as having a circular cross section, but the present invention is not limited to this and has a polygonal cross section without departing from the spirit of the present invention. It is urgent that it should be included.

[0023]

According to the present invention, the compressive force and frictional force acting on the catalyst can be reduced, so that the destruction of the catalyst can be reduced.

This makes it possible to suppress an increase in the pressure loss of the reaction gas due to the miniaturization due to the destruction of the catalyst and to extend the replacement time interval of the catalyst.

[Brief description of drawings]

FIG. 1 is an overall vertical cross-sectional view of a reformer of a fuel cell device which is an example of a catalytic reaction device according to the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is an enlarged vertical sectional view of a main part of FIG.

FIG. 4 is a sectional view taken along the line IV-IV of FIG.

FIG. 5 is a partial cross-sectional view illustrating the operation of the present invention.

[Explanation of symbols]

 1 Outer Cylinder 2 Inner Cylinder 3 Catalyst 4 Gap 5 Eyelet 6 Shell 7 Burner 8 Insulating Material 9 Reactive Gas 10 Reformed Gas 12 First Support 13 Second Support

Claims (3)

[Claims] 1. An inner cylinder, an outer cylinder arranged concentrically with the inner cylinder,
A catalyst enclosed in a space formed by the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder, and catalyst holding means for holding the catalyst at the lower ends of the inner and outer cylinders are provided. In a catalytic reaction device configured to introduce the catalyst so as to pass through it, and to allow the reaction gas that has passed through the catalyst to be discharged to the outside through the inner cylinder, the catalyst holding means and a dish portion A first support means for holding the part by the outer cylinder and a second support body held by the inner cylinder, and the first support body on the inner peripheral surface of the outer cylinder, the second support body. The support body is fixed to the outer peripheral surface of the inner cylinder, and the dish portion is attached to the first and second plates.
And a plurality of reaction parts each including the inner and outer cylinders arranged side by side, and these are accommodated in a shell. 2. The catalytic reaction device according to claim 1, wherein the inner cylinder and the outer cylinder are formed in a circular cross section. 3. One end of the outer cylinder is open and the other end is closed,
2. The catalytic reaction device according to claim 1, wherein one end of the inner cylinder is connected to a means for leading out the reaction gas, and the other end is opened near the closed portion of the outer cylinder.