JPH0425059B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an alcohol reformer that heats and reacts alcohol and water to generate hydrogen gas.

[Prior art and its problems]

As a method for producing hydrogen gas, a reformer is known that heats alcohol and water to produce a gas containing hydrogen gas. A conventional reformer will be described below with reference to the drawings.

FIG. 3 is a sectional view of the main structure of a conventional reformer, and FIG. 4 is a sectional view taken along the line CC in FIG. Third
In the figure, a burner 8 equipped with an outlet (not shown) for supplying fuel and combustion air is connected to an upper wall 1a of the combustion chamber 1.
is located in the center of the Furthermore, the combustion chamber upper wall 1
A is provided with an exhaust manifold 17 for discharging the reformed and generated hydrogen-containing gas. In the exhaust manifold 17, a plurality of reforming catalysts 9, such as reaction tubes filled with fine powders of copper oxide and zinc oxide, are arranged vertically along the combustion chamber body wall 1c as shown in FIG. Then, a pigtail 15 is connected to the opening at the bottom of each reaction tube 2, the other end of these picktails 15 is connected to a header 16 as a manifold, and the reformed fuel inlet pipe 12 connected to the opening at the bottom of the header 16 is used for combustion. It penetrates the lower room wall 1b. A ventilation guide 7 is provided in the combustion chamber 1 to cover the flame 8a from the burner 8 to guide the fuel gas, and an outlet 1 for the combustion gas is provided in the combustion chamber body wall 1c.
1 is provided.

With the above structure, alcohol, for example, a mixture of methanol and water is fed into the reformed fuel inlet pipe 12 and into each reaction tube 2 via the header 16.
When the temperature of the reaction tube 2 is raised to about 250°C by the flame and combustion gas burned by the burner 8, the reforming reaction is promoted in the reaction tube under the action of the catalyst and hydrogen is generated at the same time. Hydrogen-containing gas can be taken out from the reformed gas outlet 13 through the manifold 17 along with carbon dioxide and the like.

By the way, in this case, the reaction tube 2 and the combustion chamber body wall 1c
A difference in thermal expansion occurs due to a temperature difference due to combustion or a difference in temperature between the reaction tubes, but this difference in thermal expansion is absorbed by the picktail 15. For this reason, the picktail 15 is made of a material with high toughness and corrosion resistance, and has a structure with low rigidity.

However, when making the reformer smaller, it is necessary to hermetically weld the pigtail 15 to the reaction tube 2 and header 16, but since there is not enough space due to the small size, it is difficult to perform airtight welding, and the reliability of the welded part is reduced. There is a problem with the decline. There is also the problem that the length of the pigtail 15 is not long enough to absorb the difference in thermal expansion due to its small size.

[Purpose of the invention]

In view of the above-mentioned points, it is an object of the present invention to provide an alcohol reformer that can absorb differences in thermal expansion and can be made smaller.

[Summary of the invention]

According to the present invention, a plurality of reaction tubes filled with catalyst are arranged vertically in a combustion chamber, and alcohol and water are passed to the reaction tubes through supply and discharge manifolds communicating with the reaction tubes. In an alcohol reformer that generates a hydrogen-containing gas from a mixed liquid with a reaction tube, elastic tube sheets are provided at the upper and lower ends of the reaction tube, and supply and discharge manifolds are respectively provided covering the tube sheets, The circumferential edges of the tube sheets provided at both ends of the reaction tube are fixedly attached to the combustion chamber body wall, the combustion chamber body wall is bisected in a direction perpendicular to the center line of the reaction tube, and a bellows is inserted in the part. achieved by doing.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view of an alcohol reformer according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line BB in FIG. Figures 1 and 2, Figures 3 and 4
The same parts as in the conventional example in the figure are given the same reference numerals. In FIGS. 1 and 2, the structure and function of the burner 8, ventilation guide 7, and combustion gas outlet 11 are the same as those of the prior art, but in this embodiment, a plurality of A supply manifold 16 and a discharge manifold 17 are attached to a lower tube sheet 5 and an upper tube sheet 3, respectively, to which both ends of the reaction tube 2 are attached. Note that the upper and lower tube plates 3 and 5 have low rigidity to facilitate elastic deformation.

On the other hand, the inlet pipe 12 serving as the inlet of the supply manifold 16 passes through the bottom of the supply manifold 16 in an airtight manner.

A mesh plate 18 is provided at the bottom of the reaction tube 2 to allow a mixture of methanol and water from the supply manifold 16 to flow into the reaction tube 2 and to hold the catalyst 9 therein. Furthermore, combustion chamber 1, reaction tube 2, supply and discharge manifold 1
6 and 17 are both made of corrosion-resistant and high-temperature resistant materials, such as austenitic stainless steel.

With the above structure, when fuel and combustion air are sent from the burner 8 to perform combustion, the mixture of methanol and water sent from the inlet pipe 12 to the supply manifold 16 reacts. A reforming reaction takes place in pipe 2 and hydrogen-containing gas is produced and removed from outlet pipe 13 via exhaust manifold 17 .

Furthermore, the peripheral edges of the upper tube sheet 3 and lower tube sheet 5 of the reaction tube 2 are fixedly attached to the combustion chamber body wall 1c. Then, the combustion chamber body wall 1c is divided into two parts in a direction perpendicular to the center line of the reaction tube 2, and a bellows 10 is inserted and attached to this part. Therefore, the difference in thermal expansion due to the temperature difference between the reaction tube 2 and the combustion chamber body wall 1c can be absorbed by the free expansion of the combustion chamber body wall 1c in the bellows 10. Further, the difference in thermal expansion between the reaction tubes 2 can be absorbed by deformation of the upper and lower tube plates 3 and 5, which have low rigidity.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, the alcohol reformer can be made smaller by providing supply and discharge manifolds covering the tube sheets provided at both ends of the reaction tube. be. The peripheral edge of the tube sheet is fixedly attached to the combustion chamber, but by dividing the combustion chamber body wall into upper and lower halves and inserting bellows, the difference in thermal expansion due to the temperature difference between the reaction tube and the combustion chamber can be absorbed. Since the thermal expansion difference between the reaction tubes can be absorbed by the elastic tube sheet, the thermal stress caused by the thermal expansion difference that can lead to damage to the reformer can be reduced, and a reliable alcohol reformer can be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an alcohol reformer according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line BB in FIG. 1, FIG. 3 is a sectional view of a conventional alcohol reformer, and FIG. FIG. 4 is a sectional view taken along line CC in FIG. 3; 1: Combustion chamber, 2: Reaction tube, 3: Upper tube sheet, 5:
Lower tube plate, 9: catalyst, 10: bellows, 12:
Pipe, 16: Supply manifold, 17: Discharge manifold.

Claims (1)

[Claims] 1. A plurality of reaction tubes filled with a catalyst are arranged vertically in a combustion chamber, and a hydrogen-containing gas is generated from a mixed liquid of alcohol and water that flows into the reaction tubes via a supply manifold communicating with the reaction tubes. In the alcohol reformer, elastic tube sheets are provided at the upper and lower ends of the reaction tube, supply and discharge manifolds are respectively provided covering the tube sheets, and the tube sheets provided at both ends of the reaction tube are provided with elastic tube sheets. An alcohol reformer characterized in that each of the peripheral edges is fixedly attached to a combustion chamber body wall, the combustion chamber body wall is divided into two in a direction perpendicular to the center line of the reaction tube, and a bellows is inserted in the part. .