JPH0660001B2 - Endothermic reaction device - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an endothermic reaction apparatus, and more particularly to improvement of an endothermic reaction apparatus equipped with a plurality of double tube regeneration type reaction tubes.

[Technical Background of the Invention and its Problems] As is known, a double-tube regenerative reaction tube is composed of a reaction tube outer tube whose one end is closed and a reaction tube inner tube whose both ends are open. The pipe having an annular cross section surrounded by the reaction tube outer tube and the reaction tube inner tube constitutes a reaction chamber, and the reaction chamber is filled with a catalyst as required. The raw material gas is introduced from the opening of the outer tube of the reaction tube and passes through the reaction chamber, then reaches the closed portion of the outer tube of the reaction end and is guided to one end of the inner tube of the reaction tube. The inside of the reaction tube inner tube is a regeneration chamber, and the reaction product gas is discharged from the other end side of the reaction tube inner tube through the regeneration chamber. On the other hand, the heat of reaction required for the endothermic reaction and the sensible heat necessary for raising the raw material gas to the desired reaction temperature are mainly obtained by heating the outer tube of the reaction tube from the outside with combustion gas or other high temperature gas. The reaction product gas is partially supplied to the reaction chamber by heating the inner tube of the reaction tube when the reaction product gas is discharged through the regeneration chamber.

By the way, in the above-mentioned double tube regeneration type reaction tube, since the gas inlet / outlet is only on one end side of the reaction tube, it is not necessary to fix the other end side, that is, the closed portion of the outer tube of the reaction tube. It is easy to deal with the thermal expansion, and part of the sensible heat of the reaction product gas is recovered in the regeneration chamber as described above, so that the thermal efficiency of the device is improved and
It has an excellent feature that the post-treatment facility for the produced gas becomes inexpensive because the discharge temperature of the produced gas is lowered. Therefore, it can be suitably used for a steam reforming device or the like which requires an endothermic reaction particularly at a high temperature.

However, when a large number of such double-tube regeneration type reaction tubes are used, and particularly when trying to design the apparatus compactly by arranging these reaction tubes densely, there are some problems in the conventional method. Occurs. In other words, as a method for densely arranging the double tube regeneration type reaction tubes and distributing and supplying the raw material gas to them, and collecting the generated gas, there are conventionally a method using a pigtail and a method using a double tube plate. There is.
First, the pigtail method is a method in which the raw material gas collecting pipe or the produced gas collecting pipe and the respective reaction pipes are connected by a thin connecting pipe (pigtail). However, when this method is applied to a densely arranged double tube regeneration type reaction tube, the pigtails are concentrated on one end side of the reaction tube, which causes a problem that the structure becomes very complicated. Furthermore, when replacing the catalyst in the reaction tube, it is necessary to disconnect all the pigtails, which causes a serious problem in maintenance of the apparatus.

On the other hand, the method using the double tube plate is provided with two tube plates, an outer tube tube for the reaction tube and a tube plate for the inner tube of the reaction tube, which are spaced in parallel from each other.
In this method, the space sandwiched by these two tube plates is used as the source gas manifold, and the space outside the tube plate for the inner tube of the reaction tube is used as the production gas manifold. According to this method, the structure is simple and the replacement of the catalyst is relatively easy. However, when the reactor is used under pressure, a thick tube plate is required, resulting in a high cost and a drawback that thermal deformation such as tilting of the reaction tube tends to occur due to uneven temperature of the tube plate. Have. For this reason, it is difficult to use this method especially for applications in which a high-temperature gas side outside the reaction tube is filled with a heat-conductive filler to promote heat transfer.

[Object of the Invention] The present invention has been made to solve the above problems, and its object is to provide a compact and inexpensive structure while using a plurality of double-tube regenerative reaction tubes, and It is an object of the present invention to provide an endothermic reaction device which facilitates replacement of a catalyst in a tube and can prevent uneven inclination due to thermal deformation of a reaction tube even when used at high temperature.

[Summary of the Invention] In order to achieve the above object, in the present invention, the above-mentioned outer tube of a reaction tube is attached by penetrating a lower tube sheet and an upper tube sheet which are parallel and spaced from each other. A space surrounded by the plate and the outer tube of the reaction tube is used as a product gas manifold, and the reaction product gas is passed through a regeneration chamber provided inside the inner tube of the reaction tube, and then penetrated through the outer tube of the reaction tube to perform the regeneration. It is characterized in that the chamber is guided to the generated gas manifold through an inner pipe connecting pipe provided to connect the generated gas manifold.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing an example of the constitution of an endothermic reaction device according to the present invention. In the figure, inside a reactor vessel 1, a plurality of double-tube regeneration type reaction tubes, which are an outer tube 2 for a reaction tube and an inner tube 3 for a reaction tube, are densely arranged. The conduit having an annular cross section between the reaction tube outer tube 2 and the reaction tube inner tube 3 constitutes a reaction chamber 4, which is filled with a catalyst 5 for promoting an endothermic reaction. Further, the reaction tube outer tube 2 penetrates through two tube plates, a lower tube plate 6a and an upper tube plate 6b, which are parallel and spaced from each other, and is hermetically attached to these tube plates 6a, 6b. . On the other hand, one end of the inner pipe connecting pipe 8 is connected to the upper end of the regeneration chamber 7 formed inside the reaction pipe inner pipe inner pipe 3, and the other end of the inner pipe connecting pipe 8 is connected to the reaction pipe outer pipe 2 2 through the tube plate 6
The produced gas manifold 9 is surrounded by a and 6 b and the reaction tube outer tube 2. Further, the reaction tube outer tubes 2 adjacent to each other are connected to each other near the upper end portion thereof by the outer tube connecting tube 10 so that the raw material gas can be supplied to all the reaction tubes.

Further, 11 is a raw material gas inlet nozzle for penetrating the reactor vessel 1 from the outside, for supplying a raw material gas into the reaction tube outer tube 2 from its upper end, and 12 is a reaction gas from the generated gas manifold 9. It is a generated gas nozzle for penetrating the container 1 to the outside and discharging the generated gas to the outside. Further, 13 is a combustion chamber formed as a space in the lower portion inside the reactor vessel 1, and the combustion chamber 13 is provided with a fuel gas supplied through a fuel inlet nozzle 14 and an air inlet nozzle 15 and an oxidation gas. A burner nozzle 16 for burning combustion air as an agent is provided. Furthermore, 17 is a combustion gas passage which is formed outside the reaction tube outer tube 2 and through which a combustion gas which is a high temperature gas generated in the combustion chamber 13 passes, and 18 shows the combustion gas passage 17 from which the reactor vessel 1 is connected. A combustion gas outlet nozzle for penetrating the outside and discharging combustion gas to the outside, and a reaction tube end plate 19 for closing the upper end of the reaction tube outer tube 2.

In the above, the combustion gas passage 17 may be filled with a filling heat transfer material for promoting heat transfer. A heat-resistant material such as alumina balls can be preferably used as the filling heat transfer material. When a lean fuel gas is used as the fuel gas or when low-concentration oxygen air is used as the combustion air, the combustion chamber 13 may be filled with an oxidation catalyst for the purpose of promoting the combustion reaction.

In such an endothermic reaction apparatus, the raw material gas passes through the raw material gas inlet nozzle 11 and one or several reaction tube outer tubes 2
Will be introduced to. This source gas is distributed and supplied to each reaction tube by the outer tube connecting tube 10. Then, the raw material gas supplied to each reaction tube passes through the reaction chamber 4 and the catalyst 5
And the heating from the reaction tube outer tube 2 and the reaction tube 3 cause an endothermic reaction, and a product gas is introduced into the regeneration chamber 7 from the lower end of the reaction chamber 4. The produced gas passes through the regeneration chamber 7, and further passes through the inner pipe connecting pipe 8 to be collected in the produced gas manifold 9. When the generated gas passes through the regeneration chamber 7, its sensible heat is supplied to the inner tube 3 of the reaction tube, and then discharged from the generated gas outlet nozzle 12 provided in the generated gas manifold 9. On the other hand, the fuel gas introduced from the combustion inlet nozzle 14 and the combustion air introduced from the air inlet nozzle 15 flow into the combustion chamber 13 which is the space below the reactor vessel 1, and the burner nozzle 16 By the combustion chamber 13
These burn within. Then, as a result, the combustion chamber 13
The high temperature combustion gas generated in 1 is introduced into the combustion gas passage 17, and after heating the reaction tube outer tube 2, the combustion gas outlet nozzle 1
Emitted from 8.

As described above, in the endothermic reaction device of this structure, the reaction tubes are connected by the two tube plates 6a and 6b,
The configuration is simpler than that of the pigtail method described above. Further, since the two tube plates 6a and 6b are connected to each other by the reaction tube outer tube 2, even when the reaction chamber 4 side is pressurized, the shear stress and bending applied to the tube plates 6a and 6b are increased. The stress due to the moment is remarkably reduced as compared with the conventional method using the double tube sheet, so that the tube sheet having an extremely small thickness is sufficient. Also, since the two tube sheets 6a and 6b have the same gas in contact with each other at the upper and lower sides, the temperatures are also substantially the same, which, in combination with the thin sheet thickness, prevents deformation due to thermal expansion. Will be done. Therefore, the reaction tubes attached to the tube plates 6a and 6b are not inclined due to the deformation of the tube plates, which means that the combustion gas passage 17 is filled with the filling material for promoting heat transfer. To facilitate. Further, in this configuration, the catalyst in the reaction chamber 4 can be easily replaced by cutting the end plate 19 portion of the reaction tube outer tube 2 or forming a flange structure.

Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, in the above-mentioned embodiment, the reaction tube is arranged so that the gas inlet / outlet tube faces upward, but it may be arranged upside down. Further, the outer pipe connecting pipe 10 may be provided between the two tube plates 6a and 6b.

Further, in the above-mentioned embodiment, the combustion gas obtained by burning the combustion gas and the combustion air in the combustion chamber inside the reactor vessel was used as the high temperature gas, but the high temperature gas such as other construction gas is not limited to this. May be used.

[Effects of the Invention] As described above, according to the present invention, a compact and inexpensive structure is used while using a plurality of double-tube regenerative reaction tubes,
In addition, it is possible to provide an endothermic reaction device that facilitates replacement of the catalyst in the reaction tube and can prevent uneven inclination due to thermal deformation of the reaction tube even when used at high temperature.

[Brief description of drawings]

FIG. 1 is a cross sectional view showing an embodiment of the present invention. 1 ... Reactor container, 2 ... Reaction tube outer tube, 3 ... Reaction tube inner tube, 4 ... Reaction chamber, 5 ... Catalyst, 6a ... Lower tube sheet, 6
b ...... Upper tube sheet, 7 ...... Regeneration room, 8 ...... Inner tube connecting tube, 9
...... Generated gas manifold, 10 …… Outer pipe connecting pipe, 11…
... Raw material gas inlet nozzle, 12 ... Generated gas outlet nozzle,
13 ... Combustion chamber, 14 ... Fuel inlet nozzle, 15 ... Air inlet nozzle, 16 ... Burner nozzle, 17 ... Combustion gas passage, 18 ... Combustion gas outlet nozzle, 19 ... Reaction tube end plate.

Claims (2)

[Claims] 1. A reaction vessel having a reaction vessel, an inner tube of the reaction tube, and an inner tube of the reaction tube, the reaction vessel being surrounded by the outer tube of the reaction tube and the inner tube of the reaction tube. With a plurality of reaction tubes formed, the high temperature gas is discharged from the one end of the outer tube of the reaction tube through the outside thereof to heat the reaction chamber to the outside of the reactor vessel from the other end,
In the endothermic reaction device configured to flow the raw material gas from the other end of the reaction tube outer tube into a reaction gas through the reaction chamber and further to flow out from the other end through the inside of the reaction tube inner tube from the one end thereof, The reaction tube outer tube is attached by penetrating the lower and upper tube sheets that are parallel to each other and spaced from each other, and communicates with the outside surrounded by the reaction tube outer tube and the lower and upper tube sheets. The space portion is formed as a generated gas manifold, and the generated gas outlet side of the inner tube of the reaction tube and the generated gas manifold are configured to communicate with each other by an inner tube connecting tube provided through the outer tube of the reaction tube. An endothermic reaction device characterized by the above. 2. A reaction vessel, a reaction vessel disposed inside the reaction vessel, having a reaction tube outer tube and a reaction tube inner tube, surrounded by the reaction tube outer tube and the reaction tube inner tube. With a plurality of reaction tubes formed, the high temperature gas is discharged from the one end of the outer tube of the reaction tube through the outside thereof to heat the reaction chamber to the outside of the reactor vessel from the other end,
In the endothermic reaction device configured to flow the raw material gas from the other end of the reaction tube outer tube into a reaction gas through the reaction chamber and further to flow out from the other end through the inside of the reaction tube inner tube from the one end thereof, The reaction tube outer tube is attached by penetrating the lower and upper tube sheets that are parallel to each other and spaced from each other, and communicates with the outside surrounded by the reaction tube outer tube and the lower and upper tube sheets. The space portion is formed as a generated gas manifold, and the generated gas outlet side of the inner tube of the reaction tube and the generated gas manifold are communicated with each other by an inner tube connecting tube provided through the outer tube of the reaction tube, and adjacent to each other. An endothermic reaction device characterized in that the raw material gas inflow side of each of the reaction tube outer tubes is connected by an outer tube connecting tube.