JPS61114730A - Catalytic reaction apparatus - Google Patents

Abstract

PURPOSE:To suppress the expansion and contraction of a reaction tube caused by the heat of catalytic reaction, by constituting a catalyst holding means from a tray part, a first support for holding the tray part by an outer cylinder and a second support for holding said tray part by an inner cylinder. CONSTITUTION:Reaction gas 9 comprising a mixture of natural gas and steam is guided to a space part packed with a catalyst 3 and heated herein by a burner 7 to generate steam reforming reaction. The formed gas containing a large amount of hydrogen passes along the inner peripheral surface of an inner cylinder 2 to be sent out to the outside of a shell 8 as gas 10. The inner cylinder 2 is thermally expanded after an outer cylinder 1 was thermally expanded but, because the inner cylinder 2 is extended to the longitudinal direction, a mesh tray is supported by a second support 13 and the compression of the catalyst 3 due to the reduction of a gap 4 can be suppressed. Thereafter, the apparatus enters a steady and the mesh tray 5 is supported by first and second supports 12, 13.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalytic reaction apparatus, and more particularly to a catalytic reaction apparatus that prevents destruction of a catalyst due to thermal expansion and contraction of a reaction tube in which a catalyst is enclosed.

[Background of the invention]

A device that is equipped with an outer cylinder and an inner cylinder, and causes a chemical reaction by passing a reaction gas while heating it through a reaction section 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. An example of this is a re-former for a fuel cell device. This re-former introduces a mixed gas of natural gas and water vapor into the above-mentioned space, where it is heated from the outside by a burner to form a gas containing a large amount of hydrogen.

In the refoma configured in this way.

The radial dimension of the space between the outer cylinder and the inner cylinder (hereinafter referred to as the gap) is determined at the time of startup (starting operation) and the time of shutdown (
(when stopped), its size differs depending on thermal expansion. Therefore, when the gap widens, the catalyst particles placed in the space fall under their own weight to fill the gap created by the widening of the gap. Conversely, when the gap contracts, the catalyst particles are pushed upwards, but at this time, forces that try to destroy the catalyst, such as compressive force and frictional force, act on the catalyst, making it difficult for the equipment to start or stop. As the process is repeated, the catalyst is destroyed.

This phenomenon is explained in Gas Research In
On 5ite Fuel Ce by 5tiute
1l Power Plant Technology
and DevLopnent, Progra+
w, Annual Report (Jan 1982-J
1983), it is called ``slumping'' and discussed.

However, as a method to prevent this slumping, it has been proposed to simply provide a plurality of shelves in the longitudinal direction of the space between the outer cylinder and the inner cylinder to support the catalyst. .

It does not inherently prevent catalyst migration due to shutdown, nor does it inherently prevent catalyst destruction.

By the way, the inner diameter is 100m+i and the length is 1600mm (
7) To specifically show an example of thermal expansion of an inner cylinder with an inner diameter of 30 mm and a length of 1500 mm, the thermal expansion is 0 in the radial direction of the outer cylinder.
, 36m+o.

Thermal expansion is 18 mm in the longitudinal direction, 1.2 mm in the radial direction of the inner cylinder, and 191 mm in the longitudinal direction! It has a thermal expansion of III+.

[Purpose of the invention]

An object of the present invention is to provide a means for suppressing destruction of a catalyst caused by expansion and contraction of a reaction tube caused by reaction heat of the catalyst.

[Summary of the invention]

In order to achieve the above object, the present invention is configured such that the support of the catalyst holding means is changed when the catalytic reaction apparatus is started up and when it is stopped down. With this configuration, the compressive force and frictional force applied to the catalyst can be reduced, and the destruction of the catalyst can be suppressed.6 [Embodiment of the Invention] Hereinafter, an embodiment of the present invention is shown in Figs. 1 to 5. I will explain based on this.

FIG. 1 and FIG. 2 show a rifohmer of a fuel cell device as an example of a catalytic reaction device. As shown in the figure, the refohmer is arranged concentrically with the inner cylinder 2 and the inner cylinder 2. The reaction parts H8 to H7 are composed of an annular part formed by the outer peripheral surface of the outer cylinder 1 and inner @2 and the inner peripheral surface of the outer cylinder 1, that is, the catalyst 3 sealed in the space; The main parts are a shell 6 arranged to surround it and a burner 7 that heats the reaction sections H1 to H7. The inner tube 2 and the outer tube 1 have circular cross sections, one end of the outer tube 1 is open and the other end is closed, and one end of the inner tube 2 is open to the reaction gas 9.
The other end is opened near the closed end of the outer cylinder 1. Further, the reaction parts H, to H7 are arranged in parallel in the shell 6, and the pipe line 11 is arranged in the shell 6.
Inside, one end of the WIJ2 of each reaction section is assembled. 8 is a heat insulating material of the shell 6.

Furthermore, in FIG. 1, 5 indicates the outer cylinder 1. A perforated plate that holds the catalyst 3 at the lower end of the inner cylinder 2 is supported by a support as shown in detail in FIG. As shown in FIG. 3, the perforated plate 5 is formed into an annular shape so as to fit into the space formed by the outer circumferential surface of the inner tube 2 and the inner circumferential surface of the outer tube 1. As shown in FIG. 12.13 is
The first plate supports the perforated plate 5 at the lower ends of the outer cylinder 1 and the inner cylinder 2. Second
The supports are each shaped like a ring. Then,
The outer circumferential surface of the first support body 12 is fixed to the inner circumferential surface of the outer tube 1 , and the inner circumferential surface of the second support body 13 is fixed to the outer circumferential surface of the inner tube 2 . Also, 1st. The area of each of the second supports 1 and 2 facing the lower surface of the perforated plate 5 is configured to be large enough to allow the perforated plate 5 to be moved independently. Place the perforated plate 5 in the first position. The reason for supporting by the second support body 12.13 is as follows.

When starting up the re-former, the outer cylinder 1 thermally expands, and then the inner cylinder 2 thermally expands. Therefore, in this case, the second support 13
By supporting the perforated plate 5, compression destruction of the catalyst 3 can be prevented. The reason for this is that, for example, contrary to the above, the first support 1
2 (this means that the second support body 13 does not exist), when the outer cylinder 1 extends in the radial and longitudinal directions, the catalyst 3 will descend by its own weight by the volume increase. After that, when the inner cylinder 2 expands, there is no place for the catalyst 3, which has descended under its own weight, to escape (there is no choice but to raise the catalyst 3), and the catalyst 3 becomes susceptible to compression failure.

In contrast to the binary structure, if the perforated plate 5 is supported by the second support 13, the second support 13 also moves in the longitudinal direction as the inner cylinder 2 expands, so that the volume can be increased. Therefore, the catalyst that has come down due to its own weight is not compressed.

In addition, when the re-former is brought down, the frictional energy of the outer cylinder 1 is likely to be consumed first in destroying and deforming the catalyst 3, so in this case, it is better to have a smaller frictional area.
The perforated plate 5 is supported by a first support 12.

Returning to FIG. 1, in the re-former configured as described above, the reaction gas 9, which is a mixture of natural gas and water vapor, is guided into a space in which a catalyst 3 is enclosed, where it is heated by a burner 7 and steamed into water. A reforming reaction occurs, resulting in a gas containing a large amount of hydrogen, which passes through the inner peripheral surface of the inner cylinder 2 and becomes gas 10.
It is sent out to the outside of the shell 8 as a. In addition, Figures 1 to 3
In the figure, 4 is the radial dimension of the space between the outer cylinder 1 and the inner cylinder 2, that is, the gap.

Next, the operation of the embodiment configured as described above will be explained based on FIG. 5. In FIG. 5, (A) is a diagram explaining the state of one reaction section of the catalytic reaction apparatus, that is, when the re-former is stopped, (B) is the diagram at startup, (C) is the diagram during steady operation, and (D ) is a diagram illustrating the state at the time of falling, and (E) is a diagram explaining the state at the time of stopping. In FIG. 5, the same parts as those in FIGS. 1 to 4 are designated by reference numerals.

First, in the state shown in FIG. 5(A), the perforated plate 5 is placed in the first position. It is supported on a second support 12.13.

Next, in the state shown in FIG. 5(B), after the outer cylinder 1 has thermally expanded, the inner cylinder 1! I2 thermally expands, but since the inner cylinder 2 extends in the longitudinal direction, the perforated plate 5 is supported by the second support 13, and the gap 4
It is possible to suppress compression of the catalyst 3 due to a decrease in . Thereafter, the device is in a steady state, and the perforated plate 5 is in the first position. Supported by the second support 12.13 (state shown in Figure 5(C))
.

Next, the state shown in FIG. 5(D) will be explained.

In this state, the outer cylinder 1 contracts first, and the inner cylinder 2 contracts later.
contracts, but the perforated plate 5 is lifted upward by the first support plate 12. At this time, the catalyst 3 rises while rubbing against the outer ftJI and the pipe wall of the inner cylinder 2. It is thought that this frictional energy is consumed in the destruction and deformation of the catalyst, but in this case, if the catalyst 3 is evenly packed, it is due to the own weight of the catalyst 3 that is applied to the pipe walls of the outer cylinder 1 and the inner cylinder 2. The force per unit area is the same for both the outer cylinder 1 and the inner cylinder 2. Therefore, the frictional force F is.

F=trPS (where, μ: coefficient of friction between the catalyst and the tube wall,
P: Force per unit area (average in height direction).

S: Frictional area) Since the catalyst 3 is moved along the inner wall of the inner cylinder 2, the frictional force is small and the destruction of the catalyst 3 is reduced. After that, when the device is stopped, the fifth
The state moves to the state shown in FIG. It is supported on a second support 12.13.

In the above embodiments, the outer cylinder and the inner cylinder have circular cross-sections, but the present invention is not limited to this, and may include polygonal cross-sections as long as they do not depart from the spirit of the invention. Of course it is a thing.

〔Effect of the invention〕

According to the invention, the compressive force acting on the catalyst, ! 11 Since the frictional force can be reduced, there is an effect that the destruction of the catalyst can be reduced.

This suppresses the increase in the pressure loss of the reaction gas due to the fragmentation caused by the destruction of the catalyst, and makes it possible to extend the time interval for replacing the catalyst.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention. Fig. 1 is an overall sectional view of a re-former of a fuel cell device which is an example of a catalytic reaction device, Fig. 2 is a sectional view taken along the line ■-■ of Fig. 1, and Fig. 3 The figure is an enlarged view of the main part of Figure 1, Figure 4 is a sectional view taken along line IV-IV in Figure 3, and Figure 5 is an enlarged view of the main part of Figure 1.
V! i is an explanatory diagram of the operation of the present invention. 1... Inner cylinder, 2... Inner cylinder, 3... Catalyst, 4...
Gap, 5... Catalyst plate, 6... Body, 7... Burner, 8... Insulation material, 9... Reactant gas, 10...
Reformed gas, 12...first support, 13...second support. 1st factor diagram 5 CB) CC) (F)) (E)

Claims (1)

[Claims] 1. An inner cylinder, an outer cylinder arranged concentrically with the inner cylinder, and a catalyst sealed in a space formed by the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder. , comprising a catalyst holding means for holding the catalyst at the lower ends of the inner and outer cylinders, introducing the gas to be reacted so as to pass through the catalyst, and directing the reaction gas that has passed through the catalyst through the inner cylinder. In a catalytic reaction device configured to lead out to the outside, the catalyst holding means is a dish portion, a first support means that holds the dish portion with the outer cylinder, and a second support body that holds the catalyst holding means with the inner cylinder. The first support is fixed to the inner peripheral surface of the outer cylinder, the second support is fixed to the outer peripheral surface of the inner cylinder, and the dish part is fixed to the first and second supports. A catalytic reaction device characterized by being placed on the body. 2. The catalytic reaction device according to claim 1, wherein the inner cylinder and the outer cylinder are formed to have a circular cross section. 3. One end of the outer cylinder is open and the other end is closed, one end of the inner cylinder is connected to a means for introducing the reaction gas, and the other end is opened near the closed part of the outer cylinder. A catalytic reaction apparatus according to claim 1. 4. The catalytic reaction device according to claim 3, wherein a plurality of reaction sections each comprising the inner and outer cylinders are arranged in parallel and housed in a shell.