JPH04694B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention has a double pipe structure consisting of an outer pipe and an inner pipe, and an annular space formed between the outer pipe and the inner pipe is The present invention relates to a reactor equipped with a reaction tube having a catalyst bed filled with a catalyst, and in which the gas flow in the outer tube and the gas flow in the inner tube communicate with each other at one end.

[Conventional technology]

FIG. 3 shows a conventional device, for example, the one shown in Japanese Patent Application Laid-Open No. 151438/1982. In the figure, 1 is a reaction tube, 2 is an outer tube, and one end face has an intake port 2a for taking in the catalyst 3. The end cap 4 is connected to the other end. Reference numeral 5 indicates an introduction pipe for introducing raw material gas into the outer pipe 2, and reference numeral 6 indicates an inner pipe arranged concentrically with the outer pipe 2 within the outer pipe 2. It communicates with the gas stream at one end. That is, they communicate through four end caps. 7
8 is a catalyst layer formed by filling the annular space formed between the outer tube 2 and the inner tube 6 with the catalyst 3; 8 is a receiving plate that supports the catalyst 3; 9 is the other end of the inner tube 6. This is a lead-out pipe that is connected to the inner pipe 6 and leads out the reaction gas flowing inside the inner pipe 6 to the outside of the reaction tube 1. These 2 to 9 constitute the reaction tube 1 having a double-tube structure.

Next, the operation will be explained. For convenience of explanation, a steam reforming reaction apparatus will be explained as an example. Hydrocarbons and steam, which are raw material gases, are preheated to about 450°C, for example, and then introduced into the outer tube 2 through the introduction tube 5, and are then introduced into the catalyst layer 7 formed between the outer tube 2 and the inner tube 6. contact with the catalyst 3 of. Here, the raw material gas undergoes a steam reforming reaction and becomes a mixed gas (reformed gas) of H ₂ , CO, CO ₂ and the like. The steam reforming reaction is an endothermic reaction, and in order to compensate for this amount of heat, the outside of the outer tube 2 is heated to about 1000° C. by combustion gas. or,
In the steam reforming reaction, the hydrogen gas component increases as the temperature increases, so in a normal hydrogen production plant, the temperature of the reformed gas (reaction temperature) at the outlet of the catalyst layer 7 is, for example,
A temperature of about 800℃ is used. The heating of combustion gas is
It is also used to increase the temperature of this reformed gas. After the reaction, the high-temperature reformed gas passes through a plurality of small holes (not shown) in the receiving tray 8, reverses its flow at the end cap 4, passes through the inner tube 6, and exits at the outlet tube 9 while remaining at a high temperature. From there, it is led out of the reaction tube 1, that is, out of the system.

[Problem that the invention seeks to solve]

The conventional reactor is configured as described above, and in order to improve the heat transfer coefficient between the reformed gas in the inner tube 6 and the wall of the inner tube 6, the inner tube 6 is made with a small diameter and the reformed gas is Increasing the flow rate reduces the heat transfer area,
Conversely, when the heat transfer area is increased, the flow rate of the reformed gas in the inner tube 6 is reduced, and the thermal conductivity is reduced. Therefore,
The reformed gas at about 800℃ in the 4th part of the end cap is
There is a thermal waste in that it is discharged out of the system while still being at a high temperature. In addition, there was a problem in that there was a difference in temperature between the outer tube side, the center portion, and the inner tube side of the catalyst layer 7, and the temperature was particularly low in the center portion, deteriorating the characteristics of the reforming reaction.

The purpose of the reactor of the present invention is to provide a reactor that effectively utilizes the sensible heat of the high-temperature gas passing through the inner tube without wasting it.

[Means for solving problems]

In the reactor according to the present invention, the heat absorbing part is disposed in the gas flow passing through the inner tube, the heat dissipating part is disposed on the raw material gas introduction side of the catalyst layer and approximately at the center of the outer tube and the inner tube, and It is equipped with a plurality of heat pipes filled with working fluid and arranged radially.

[Effect]

In the reactor according to the present invention, the sensible heat of the high-temperature gas passing through the inner tube is absorbed by the heat absorption part of the heat pipe, and the heat is transported to the heat radiation part of the heat pipe,
Heat is radiated through the heat radiating portion to the raw material gas introduction side and substantially central portion of the catalyst layer.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In Figures 1 and 2, 1 to 3, 5 to 7,
9 has the same structure as the conventional device described above. 10
The heat absorption part 10a is arranged in the high temperature gas flow passing through the inner pipe 6 and flowing into the outlet pipe 9, and the heat radiation part 10b is arranged on the raw material gas introduction side of the catalyst layer 7 and approximately in the center between the outer pipe 2 and the inner pipe 6. inside, cesium, potassium,
These are heat pipes in which a working liquid such as sodium is sealed, and a plurality of heat pipes are provided radially as shown in FIG.

Next, the operation will be explained. Hydrocarbons and steam, which are raw material gases, are preheated to about 450°C, for example, and then introduced into the outer tube 2 from the introduction tube 5 as in the conventional case, and come into contact with the catalyst 3 in the catalyst layer 7, where they undergo steam reforming. produce a reaction. After the reaction, the high temperature reformed gas passes through a plurality of small holes (not shown) in the receiving tray 8, reverses its flow at the end cap 4, and flows into the inner tube 6.
It is discharged to the outside of the system through the outlet pipe 9. By the way, the high temperature reformed gas flowing into the outlet pipe 9 through the inner pipe 6 comes into thermal contact with the heat absorption part 10b of the heat pipe 10, and the sensible heat of the high temperature reformed gas is transferred to the heat pipe 1.
0 is absorbed by the heat absorption part 10a. That is, the heat absorption part 10a of the heat pipe 10 is heated, and this heating also heats the working liquid sealed inside the heat pipe 10, which absorbs the sensible heat of the high-temperature reformed gas as latent heat of vaporization and vaporizes the heat pipe 10. Heat radiation part 10
Move inside to b. The vapor of the working liquid that has moved to the heat radiation part 10b of the heat pipe 10 is transferred to the catalyst layer 7.
Heat is radiated into the raw material gas introduced into the reactor to compensate for the temperature increase or reaction heat of the raw material gas or reformed gas.
At this time, the vapor of the working liquid 11 is condensed and liquefied. The condensed and liquefied working fluid is transferred to heat pipe 1.
0 and returns to the heat absorption section 10a. In this way, by repeatedly vaporizing and liquefying the working liquid in the heat pipe 10, the sensible heat of the high temperature reformed gas that has passed through the catalyst layer 7 is effectively absorbed by the heat absorbing portion 10a of the heat pipe 10. This heat is transported to the heat dissipation section 10b of the heat pipe 10, and is radiated and transferred to the raw material gas introduction section of the catalyst layer 7 where the reaction is particularly strong and the amount of heat absorbed is large, and approximately at the center between the outer tube 2 and the inner tube 6. This makes it possible to increase the temperature of the central portion, significantly reduce the temperature difference between the outer tube side, the central portion, and the inner tube side of the catalyst layer 7, and obtain effective reaction characteristics. After being effectively utilized, the reformed gas is discharged to the outside of the system through the outlet pipe 9. Accordingly, it becomes possible to downsize the device and reduce the amount of auxiliary fuel.

Further, heat transfer fins (not shown) may be provided in the heat absorption part 10a and the heat radiation part 10b of the heat pipe 10 to enhance the heat absorption effect and the heat radiation effect.

〔Effect of the invention〕

As explained above, in this invention, the heat absorbing part is disposed in the gas flow passing through the inner tube, the heat radiating part is disposed on the raw material gas introduction side of the catalyst layer and approximately in the center between the outer tube and the inner tube, and A plurality of heat pipes filled with a working liquid and arranged radially are provided, and the sensible heat of the high-temperature gas passing through the inner pipe is absorbed by the heat absorption part of the heat pipe, and the heat is transferred to the heat radiation part of the heat pipe. Since the heat is radiated to the raw material gas introduction side and approximately the center of the catalyst layer through the inner tube, the sensible heat of the high temperature gas passing through the inner tube can be used effectively without wasting it, and effective reaction characteristics can be obtained. can.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a reaction apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line - FIG. 1, and FIG. 3 is a sectional view showing a conventional reaction apparatus. In the figure, 2 is an outer tube, 3 is a catalyst, 6 is an inner tube,
7 is a catalyst layer, 10 is a heat pipe, 10a is a heat absorption part, and 10b is a heat radiation part. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1 It has a double tube structure consisting of an outer tube and an inner tube, and has a catalyst layer filled with a catalyst in an annular space formed between the outer tube and the inner tube, and the catalyst is introduced into the outer tube. In the reactor, a heat absorption part is disposed in the gas flow passing through the inner pipe, and a heat radiation part is provided on the raw material gas inlet side of the catalyst layer and on the outer pipe. 1. A reaction device comprising a plurality of heat pipes disposed approximately in the center of the inner tube and the inner tube, the heat pipes having a working liquid sealed therein and arranged radially.