JPS6111135A - Endothermic reaction device - Google Patents

Abstract

PURPOSE:To prevent ununiform inclination of reaction tube at high temp. due to thermal deformation by forming a produced gas manifold from a space part communicating to external part utilizing a space enclosed by an external tube of a reaction tubes and upper and lower tube plates. CONSTITUTION:When produced gas passes through a regeneration chamber 7, the sensible heat is supplied to the internal tube 3 of the reaction chamber, and the produced gas is discharged from an outlet nozzle 12 provided to the manifold 9 of the produced gas. On one hand,fuel gas introduced from a fuel inlet nozzle 14 and combustion air introduced from a combustion air inlet nozzle 15 are introduced into the combustion chamber 13 formed as a space below the reactor vessel 1, and the gases are burnt in the combustion chamber 13 by the burner nozzle 16. The combustion gas at high temp. generated by the combustion in the combustion chamber 13 is led to a combustion gas passage 17 where it heats the external tube 2 of the reaction tube, then discharged from a discharging nozzle 18 of the combustion gas.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an endothermic reaction apparatus, and particularly to an improvement in an endothermic reaction apparatus equipped with a plurality of double snowman type reaction tubes.

[Technical evening of the invention and its problems] As is known, the double snowman type reaction tube consists of an outer reaction tube that is closed at one end and an inner reaction tube that is open at both ends. A pipe line having an annular cross section surrounded by an outer reaction tube and an inner reaction tube constitutes a reaction chamber, and this reaction chamber is filled with a catalyst as required. The raw material gas is introduced through the opening of the outer tube of the reaction tube and passes through the reaction chamber, and then reaches the closed portion of the outer tube at 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 serves as a regeneration chamber, and the reaction product gas passes through the regeneration chamber and is discharged from the other end side of the reaction tube inner tube. On the other hand, the reaction heat required for the endothermic reaction and the sensible heat required to raise the raw material gas to the desired reaction temperature are mainly generated by heating the outer tube of the reaction tube from the outside with combustion gas or other high-temperature gas. A portion of the reaction product gas is also supplied to the reaction chamber by heating the reaction tube as it exits through the regeneration chamber.

By the way, in the above-mentioned double snowman type reaction tube, the gas inlet and outlet are only on one end of the reaction tube, so there is no need to fix the other end, that is, the closed part of the reaction tube outer tube, and therefore the reaction tube It is easy to deal with thermal expansion, and as mentioned above, a part of the sensible heat of the reaction product gas is recovered in the regeneration chamber, so the thermal efficiency of the device is improved, and
It has an excellent feature in that the exhaust temperature of the reaction product gas is lowered, which makes the post-processing equipment for the product gas cheaper. Therefore, it can be particularly suitably used in steam reforming equipment and the like that require an endothermic reaction to occur at high temperatures.

However, when using a large number of such double-Yukiman-shaped reaction tubes,1 especially when attempting to design a compact device by arranging these reaction tubes densely, there are several problems with conventional methods. A problem arises.

In other words, the conventional methods for arranging these double snowman-shaped reaction tubes in a dense manner, distributing and supplying raw material gas to them, and collecting the produced gas have been two methods: one using pigtails and the other using double tube plates. There is. First, the pigtail method is a method in which a raw material gas collecting pipe or a produced gas collecting pipe and each reaction tube are communicated with each other through a thin connecting pipe (pigtail).

However, when this method is applied to densely arranged double snowman type reaction tubes, a problem arises in that the pigtails are concentrated at one end of the reaction tube, making the structure extremely complicated. Furthermore, when replacing the catalyst in the reaction tube, it is necessary to cut off all the pigtails, which poses a major maintenance problem for the apparatus.

On the other hand, in the double tube sheet method, two tube sheets, one for the outer tube of the reaction tube and the other for the inner tube of the reaction tube, are provided in parallel and spaced apart.
In this method, the space sandwiched between these two tube sheets is used as a raw material gas manifold, and the space outside the tube sheet for the inner tube of the reaction tube is used as a produced gas manifold. According to this method, the structure becomes simple and the catalyst can be replaced relatively easily. However, when using a pressurized reactor, a thick tube sheet is required, resulting in high costs, and the disadvantage is that thermal deformation such as tilting of the reaction tube is likely to occur due to uneven temperature of the tube sheet. have For this reason, it is difficult to use this method particularly in applications where a heat conductive filler is filled on the high temperature gas side outside the reaction tube to promote heat transfer.

[Object of the Invention] The present invention was made to solve the above-mentioned problems, and its purpose is to achieve a compact and inexpensive structure using a plurality of double snowman type reaction tubes, and to realize a reaction tube that is compact and inexpensive. It is an object of the present invention to provide an endothermic reaction device which allows easy replacement of a catalyst in a tube and can prevent uneven inclination of reaction tubes due to thermal deformation even when used at high temperatures.

[Summary of the Invention] In order to achieve the above object, the present invention includes the above-mentioned reaction tube outer tube being attached through a lower tube sheet and an upper tube sheet that are parallel and spaced apart from each other, so that the outer tube of the reaction tube is attached to the upper tube of the lower tube sheet. The space surrounded by the plate and the outer tube of the reaction tube is defined as a generated gas manifold, and the reaction generated gas passes through a regeneration chamber provided inside the inner tube of the reaction tube, and then passes through the outer tube of the reaction tube to be regenerated. It is characterized in that it is led to the generated gas manifold through an inner pipe connecting pipe provided to connect the chamber and the generated gas manifold.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The figure shows a cross-sectional view of an example of the configuration of an endothermic reaction device according to the present invention. In the figure, inside a reactor vessel 1, a plurality of double snowman-shaped reaction tubes consisting of an outer reaction tube 2 and an inner reaction tube 3 are densely arranged. A pipe line having an annular cross section between the reaction tube outer tube 2 and the reaction tube interior @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 passes through two tube sheets, a lower tube sheet 6a and an upper tube sheet 6b, which are parallel and spaced apart, and passes through these tube sheets 5.
A, 5b are airtightly attached. On the other hand, one end of an inner tube connecting tube 8 is connected to the upper end of the regeneration chamber 7 formed inside the reaction tube inner tube 3, and the other end of this inner tube connecting tube 8 is connected to the reaction tube outer tube 2. The two tube sheets 5a, 5 pass through
b and a reaction tube outer tube 2. Furthermore, the reaction tube outer tubes 2 adjacent to each other are connected to each other near their upper ends through an outer tube connecting tube 10 so that raw material gas can be supplied to all the reaction tubes.

Reference numeral 11 is a raw material gas inlet nozzle that is provided to penetrate the reactor vessel 1 from the outside and supplies raw material gas into the reaction tube outer tube 2 from its upper end; This is a generated gas nozzle that is provided to penetrate the container 1 to the outside and discharge generated gas to the outside. Furthermore, 13 is a combustion chamber formed as a space in the lower part of the interior of the reactor vessel 1, and inside this combustion chamber 13, fuel gas and oxidation gas are supplied through a fuel inlet nozzle 14 and an air inlet nozzle 15. A burner nozzle 16 is provided for burning combustion air as a combustion agent. Furthermore, a combustion gas passage 17 is formed outside the reaction tube outer tube 2 and through which combustion gas, which is a high-temperature gas generated in the combustion chamber 13, passes; A combustion gas outlet nozzle 19 is provided to penetrate to the outside and discharge the combustion gas to the outside. Reference numeral 19 is a reaction tube end plate for closing the upper end of the reaction tube outer tube 2.

Note that in the above, the combustion gas passage 17 may be filled with a heat transfer material to promote heat transfer. As this filling heat transfer material, for example, a heat resistant material such as alumina balls can be suitably used. Further, when using diluted fuel gas as the fuel gas or when using low concentration oxygen air as the combustion air, an oxidation catalyst may be filled in the combustion chamber 13 for the purpose of promoting the combustion reaction.

In such an endothermic reaction device, the raw material gas passes through the raw material gas inlet nozzle 11 and passes through one or several reaction tube outer tubes 2.
will be introduced in This raw material gas is distributed and supplied to each reaction tube through the outer tube connecting tube 10. Then, the raw material gas supplied to each reaction tube passes through the reaction chamber 4, and at this time, the catalyst 5
An endothermic reaction occurs due to the action of the reaction tube 2 and the heating from the reaction tube outer tube 2 and the reaction tube inner tube 3, and the resulting gas flows into the regeneration chamber 7 from the lower end of the reaction chamber 4. This 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 reaction tube inner tube 3, and then the generated gas outlet nozzle 12 provided in the generated gas manifold 9
is discharged from.

On the other hand, the combustion chamber 1 which is the space below the reactor vessel 1
Fuel gas introduced from the fuel inlet nozzle 14 and combustion air introduced from the air inlet nozzle 15 flow into the combustion chamber 3, and these are combusted in the combustion chamber 13 by the burner nozzle 16. The high-temperature combustion gas generated in the combustion chamber 13 is guided to the combustion gas passage 17, heats the reaction tube outer tube 2, and then is discharged from the combustion gas outlet nozzle 18.

As mentioned above, in the endothermic reaction apparatus of this configuration, the reaction tubes are connected by two tube plates 6a and 6b,
The configuration is simpler than the pigtail method described above. Also, two tube plates 6a.

6b are connected to each other by the reaction tube outer tube 2, so even when the reaction chamber 4 side is pressurized, the tube plate 6
The stress due to the shear stress and bending moment applied to a and 6b is significantly reduced compared to the conventional method using a double tube sheet, so it is sufficient that the thickness of the tube sheet is extremely thin. In addition, since the two tube sheets 6a and 5b are in contact with the same gas on the top and bottom, their temperatures are also substantially the same, and this, combined with the thinness of the plates, prevents deformation due to thermal expansion. This will prevent this.

Therefore, the reaction tubes attached to the tube sheets 6a and 6b will not be tilted due to deformation of the tube sheets, and this means that the combustion gas passage 17 can be filled with a filling material for promoting heat transfer. It facilitates Furthermore, in this configuration, the catalyst in the reaction chamber 4 can be easily replaced by cutting off the end plate 19 portion of the reaction tube outer tube 2 or by forming it into a flange structure.

It goes without saying that the present invention is not limited to the above-described embodiments, and can be implemented with various modifications without changing the gist thereof.

For example, in the above embodiment, the reaction tube is arranged with the gas inlet/outlet section facing upward, but it may also be arranged upside down. Further, the outer tube connecting tube 10 may be provided between two tube sheets 6a and 6b.

In addition, in the above example, the combustion gas obtained by burning combustion gas and combustion air in the combustion chamber inside the reactor container was used as the high-temperature gas, but the present invention is not limited to this, and other high-temperature gases such as construction gas It is also possible to use

"Effects of the Invention" As explained above, according to the present invention, a compact and inexpensive structure is achieved while using a plurality of double Yukiman-type reaction tubes,
Furthermore, it is possible to provide an endothermic reaction apparatus in which the catalyst in the reaction tube can be easily replaced, and even when used at high temperatures, uneven tilting due to thermal deformation of the reaction tube can be prevented.

[Brief explanation of the drawing]

The figure is a cross-sectional configuration diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Reactor container, 2... Reaction tube outer tube, 3... Reaction tube inner tube, 4... Reaction chamber, 5... Catalyst, 6a...
Lower tube sheet, 6b... Upper tube sheet, 7... Regeneration chamber, 8.
...Inner pipe connecting pipe, 9...Produced gas manifold, 10.
... Outer pipe connecting pipe, 11 ... Raw material gas inlet nozzle, 12
... Produced gas outlet nozzle, 13... Combustion chamber, 14.
...Fuel inlet nozzle, 15...Air inlet nozzle, 16
... Burner nozzle, 17 ... Combustion gas passage, 18
...One combustion gas outlet nozzle...Reaction tube end plate.

Claims (2)

[Claims] (1) A reactor container, which is disposed inside the reactor container, has an outer reaction tube and an inner reaction tube, and is surrounded by the outer reaction tube and the inner reaction tube to form a reaction chamber. A plurality of reaction tubes made of In the endothermic reaction apparatus, the endothermic reaction apparatus is configured such that the product gas flows into the reaction tube from the other end of the reaction tube through the reaction chamber, and then flows out from the other end through the inside of the reaction tube from one end of the reaction tube. are installed through the lower and upper tube sheets that are parallel to each other and spaced apart, to create a space surrounded by the reaction tube outer tube and the lower and upper tube sheets that leads to the outside. The reaction tube is formed as a gas manifold, and the produced gas outflow side of the reaction tube inner tube and the generated gas manifold are configured to communicate with each other through an inner tube connecting tube provided through the reaction tube outer tube. endothermic reactor. (2) A reactor container, which is disposed inside the reactor container, has an outer reaction tube and an inner reaction tube, and is surrounded by the outer reaction tube and the inner reaction tube to form a reaction chamber. A plurality of reaction tubes made of In the endothermic reaction apparatus, the endothermic reaction apparatus is configured such that the product gas flows into the reaction tube from the other end of the reaction tube through the reaction chamber, and then flows out from the other end through the inside of the reaction tube from one end of the reaction tube. are installed through the lower and upper tube sheets that are parallel to each other and spaced apart, to create a space surrounded by the reaction tube outer tube and the lower and upper tube sheets that leads to the outside. The reaction tube is formed as a gas manifold, and the produced gas outflow side of the inner reaction tube and the produced gas manifold are connected to each other by an inner tube connecting tube provided through the outer reaction tube, and each of the reactions are adjacent to each other. An endothermic reaction device characterized in that the raw material gas inflow side of the outer tube is connected to the outer tube connecting tube.