JP3748431B2 - Gas reforming furnace and its deposit removal method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas reforming furnace used for reforming waste gas such as municipal waste and sewage sludge and polymer gas obtained from biomass into low molecular gas such as hydrogen gas and carbon monoxide gas, and The present invention relates to a method for removing the deposits.
[0002]
[Prior art]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-144336
A polymer gas obtained from waste or biomass as described above is brought into contact with oxygen and water vapor under a high temperature condition of about 1200 ° C., and reformed into a low molecular gas such as hydrogen gas or carbon monoxide gas, As shown in Patent Document 1, it is conventionally known. Recently, a cylindrical furnace as shown in FIG. 2 is generally used as a gas reforming furnace for this purpose.
[0004]
The conventional gas conversion furnace shown in FIG. 2 is provided with a polymer gas supply port 2, an oxygen supply port 3, and a water vapor supply port 4 at the lower part of the furnace body 1, and the polymer gas blown into the furnace Oxygen and water vapor are mixed and stirred at a high temperature of about 1200 ° C. While the mixed gas is moved upward at a speed of 1.5 to 2.0 m / s, a residence time of about 4 seconds is secured, during which the reforming reaction is completed and the reformed gas is discharged from the upper outlet 5. It has a structure to take out.
[0005]
However, the gas reforming furnace having such a structure has a problem that long-term continuous operation cannot be performed because dust contained in the polymer gas derived from the waste adheres to the inner wall surface of the furnace body 1. . Further, when the furnace body 1 is enlarged, there is a problem that the mixing of the polymer gas, oxygen, and water vapor is not sufficiently performed, and the reforming efficiency is lowered. Furthermore, with the supply of water vapor, a cool spot, which is a local low temperature portion, is formed in the furnace, resulting in a problem that the reforming efficiency is lowered.
[0006]
[Problems to be solved by the invention]
The present invention solves the above-mentioned conventional problems, a gas reforming furnace in which dust contained in a polymer gas is difficult to adhere, gas mixing is good, and a cool spot is not easily formed due to the supply of water vapor It was made to provide. Another object of the present invention is to provide a gas reforming furnace capable of removing deposits without stopping the operation of the furnace even when dust contained in the polymer gas adheres to the wall of the furnace. It is to provide a kimono removal method.
[0007]
[Means for Solving the Problems]
The gas reforming furnace of the present invention made in order to solve the above-mentioned problems is a gas conversion chamber through a constricted portion into which water vapor is blown into the upper part of a cyclone-like oxygen mixing chamber into which polymer gas and oxygen are blown. Is provided. The cyclonic oxygen mixing chamber preferably serves as a dust melting chamber in the polymer gas, and the lower outlet of the cyclonic oxygen mixing chamber is preferably connected to a water seal conveyor.
[0008]
The deposit removal method for a gas reforming furnace according to the present invention includes an oxygen supply means for raising temperature or an oxygen burner in the gas conversion chamber of the gas conversion furnace, and the amount of dust adhering to the inner wall of the gas conversion chamber. When the temperature increases, the gas conversion chamber is heated to 1500 ° C. or more to melt the deposits.
[0009]
According to the gas reforming furnace of the present invention, since the polymer gas and oxygen are uniformly mixed in the cyclonic oxygen mixing chamber, the oxygen mixing chamber has a high temperature of about 1500 ° C. and is contained in the polymer gas. Dust becomes molten slag. Then, when the mixed gas passes through the throttle portion, the water vapor is mixed, reaches a temperature of about 120 ° C., moves to the gas conversion chamber above, and undergoes gas reforming while ensuring the necessary residence time. For this reason, it is possible to avoid a temperature range of around 1300 ° C. where dust becomes highly sticky, and it is difficult for deposits to form on the inner wall of the gas conversion chamber.
[0010]
Moreover, when the amount of dust adhering to the inner wall of the gas conversion chamber increases for some reason, the gas conversion chamber is opened using an oxygen supply means for raising temperature or an oxygen burner provided in the gas conversion chamber of the gas conversion furnace. By raising the temperature to 1500 ° C. or higher, the deposit can be melted and flowed down. For this reason, an easy and quick recovery is possible.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
As shown in FIG. 1, the gas reforming furnace of the present invention comprises an oxygen mixing chamber 11 and a gas conversion chamber 12 provided above the oxygen mixing chamber 11, and these are connected via a throttle 13. The lower part of the oxygen mixing chamber 11 has a conical shape like a cyclone, and a polymer gas supply port 14 and an oxygen supply port 15 are provided on the upper side wall. Waste or biomass-derived polymer gas is blown tangentially from the polymer gas supply port 14 into the oxygen mixing chamber 11, and oxygen is blown tangentially from the oxygen supply port 15 into the oxygen mixing chamber 11. It is. For this reason, the polymer gas and oxygen are uniformly mixed while being vigorously stirred inside the relatively small oxygen mixing chamber 11, and a part of the gas is burned to a high temperature of around 1500 ° C.
[0012]
Dust contained in the polymer gas blown into the oxygen mixing chamber 11 is separated from the gas while swirling in the chamber according to the principle of the cyclone and falls to the lower part. It slags and flows down from the lower outlet 16. The lower outlet 16 is sealed with a water-sealed conveyor 17, and the slag can be taken out as a granulated slag, but it is preferable that outside air is not sucked. In this way, most of the dust contained in the polymer gas is slagted in the oxygen mixing chamber 11.
[0013]
Next, the mixed gas of the polymer gas and oxygen passes through the throttle portion 13 formed at the upper center of the oxygen mixing chamber 11 and enters the gas conversion chamber 12. The inner diameter of the throttle 13 is suitably about 1/2 of the upper diameter of the oxygen mixing chamber 11. The throttling portion 13 is provided with a water vapor supply port 18 to supply water vapor heated to a high temperature. For this reason, the mixability of mixed gas and water vapor | steam becomes favorable. In addition, if the temperature of the water vapor is set to 400 ° C. or lower, a high-temperature mixed gas of about 1500 ° C. is rapidly cooled to about 1200 ° C. when passing through the throttle section 13. For this reason, it is possible to avoid a temperature range around 1300 ° C. in which dust becomes highly sticky. In addition, since the steam is mixed in the throttle portion 13 in the gas mixture that has been heated to a high temperature in this way, a conventional cool spot does not occur.
[0014]
Thereafter, the mixed gas moves inside the gas conversion chamber 12 at the same rising speed of 1.5 to 2.0 m / s as in the prior art, and a necessary residence time of about 4 seconds is secured. During this time, the gas reforming reaction to a low molecular gas such as hydrogen gas or carbon monoxide gas is completed, and the reformed gas is taken out from the upper outlet 19. As described above, most of the dust contained in the polymer gas is separated in the oxygen mixing chamber 11 and the inside of the gas conversion chamber 12 is kept at around 1100 ° C. Compared to a reforming furnace, dust does not easily adhere to the inner wall of the gas conversion chamber 12.
[0015]
However, if the operation is continued for a long period of time, dust may gradually adhere to the inner wall of the gas conversion chamber 12 and grow. Therefore, according to the deposit removal method of the present invention, when the gas conversion chamber 12 is provided with an oxygen supply means or oxygen burner 20 for raising the temperature, the amount of dust attached to the inner wall of the gas conversion chamber 12 increases. Then, the temperature of the gas conversion chamber is raised to 1500 ° C. or higher using the oxygen supply means or the oxygen burner 20.
[0016]
Thus, if it heats to 1500 degreeC or more high temperature, the deposit | attachment of the inner wall of the gas conversion chamber 12 turns into molten slag, can flow down, and can be discharged | emitted from the lower exit 16 of the oxygen mixing chamber 11. FIG. Thus, according to the present invention, the deposits can be removed without stopping the operation for a long period of time, so that the gas reforming furnace can be restored easily and quickly.
[0017]
【The invention's effect】
The effects of the present invention described above are summarized as follows.
(1) The polymer gas, oxygen and water vapor are mixed uniformly. Therefore, excellent gas reforming efficiency can be achieved.
(2) No cool spots are generated due to the addition of water vapor.
(3) Dust contained in the low molecular gas is separated into a slag by being separated in a high-temperature oxygen mixing chamber, so that it is difficult to bring it into the gas conversion chamber.
{Circle around (4)} Even if dust is brought into the gas conversion chamber, it is difficult for the dust to adhere to the inner wall because the temperature in the gas conversion chamber is below the temperature at which the dust is sticky.
(5) When dust grows on the inner wall of the gas conversion chamber, the deposits can be easily removed by raising the temperature of the gas conversion chamber to 1500 ° C. or higher.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
FIG. 2 is a sectional view showing a conventional gas reforming furnace.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Furnace body of conventional gas conversion furnace, 2 Polymer gas supply port, 3 Oxygen supply port, 4 Water vapor supply port, 5 Upper exit, 11 Oxygen mixing chamber of gas reforming furnace of this invention, 12 Gas conversion chamber, 13 Throttle part, 14 polymer gas supply port, 15 oxygen supply port, 16 lower outlet, 17 water-sealed conveyor, 18 water vapor supply port, 19 take-out port, 20 oxygen supply means or oxygen burner

Claims (4)

A gas conversion furnace characterized in that a gas conversion chamber is provided in an upper part of a cyclonic oxygen mixing chamber into which a polymer gas and oxygen are blown, through a throttle portion into which water vapor is blown. The gas reforming furnace according to claim 1, wherein the cyclonic oxygen mixing chamber also serves as a dust melting chamber in the polymer gas. The gas reforming furnace according to claim 2, wherein a lower outlet of the cyclonic oxygen mixing chamber is connected to a water-sealed conveyor. The gas conversion chamber of the gas conversion furnace according to claim 1 is provided with an oxygen supply means for raising temperature or an oxygen burner, and when the amount of dust attached to the inner wall of the gas conversion chamber increases, the gas conversion chamber is set to 1500 A method for removing deposits from a gas reforming furnace, wherein the deposits are melted by raising the temperature to at least ° C.

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