JPS6216993B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluidized bed pyrolysis apparatus for pyrolyzing organic matter such as municipal waste.

Conventionally, this type of equipment has a device part that thermally decomposes organic matter, and a combustible solid thermal decomposition residue (hereinafter referred to as char) generated along with the thermal decomposition gas. A so-called two-column circulation system was used, in which the system was separated into a section that supplied the amount of heat needed. However, although this method has the advantage of producing pyrolysis gas with a high calorific value, it requires a large installation area, so in Japan, where it is difficult to secure land, smaller equipment is desired.

Therefore, heat is supplied by combustion in the lower part of the fluidized bed of one column. If thermal decomposition is performed in the upper part, the calorific value of the generated gas will decrease, but thermal decomposition will be possible in a single tower. However, although the generated char varies depending on the pyrolysis raw material, most of the char is entrained in the gas and remains in the upper part of the fluidized bed, and only a small amount moves to the lower part of the bed due to the movement of the fluidized particles. Furthermore, even if the char is moved, it is difficult to secure the residence time necessary for the combustion of the char.

For example, Japanese Patent Laid-Open No. 54-43902 discloses a fluidized bed type thermal decomposition apparatus for municipal waste, etc. However, in this known technique, all the solid pyrolysis residue and the residue contained in the pyrolysis gas are directly discharged outside the fluidized bed furnace, resulting in a large cooling heat loss, and the combustible components contained in the residue and gas are discharged as they are. is wasted, which is unfavorable in terms of thermal efficiency. Furthermore, when a separator is installed, if it is not sealed, there is a risk of ignition due to oxygen, and the cooling effect will be reduced.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a fluidized bed type pyrolysis apparatus which can sufficiently burn the char with little heat loss and which can be easily cooled.

According to the present invention, in a fluidized bed type pyrolysis apparatus for recovering combustible pyrolysis gas by pyrolyzing organic matter such as municipal waste, a pyrolysis raw material supplying device for supplying pyrolysis raw materials to a fluidization path is provided. , a passage for collecting the combustible solid pyrolysis residue remaining at the top of the fluidized bed and another passage for separating and recovering the combustible solid pyrolysis residue from the pyrolysis gas are provided, and the residue collected from the other passage is fluidized. A screw feeder is provided directly above the gas distribution plate provided at the bottom of the bed, and a supply section is further provided to supply a fluidizing gas containing combustion oxygen to the fluidized bed.

Therefore, the pyrolysis raw material supplied to the fluidized fluidized furnace is
It is thermally decomposed and combusted while flowing in the furnace, and at this time it is sufficiently combusted by the fluidizing gas containing oxygen. The residue in the combustible gas and the combustible residue remaining in the upper part are collected in separate passages and sent into the furnace by the screw feeder. Residue can be re-supplied into the furnace. This screw feeder is installed directly above the gas distribution plate at the bottom of the furnace, so any substances that are not entrained in the gas fall below the gas distribution plate, and the rest is recirculated, ensuring sufficient combustion and decomposition. It can be carried out.

Therefore, the produced char is sufficiently combusted and decomposed with little heat loss, and since the emitted chir is substantially free of combustible matter, it can be easily cooled. Further, the pulverization of the chir is carried out by pulverizing fluidized sand, which eliminates the need for a separate external pulverizer, and the chir gradually becomes brittle and can be made finer by recirculation.

FIG. 1 shows a pyrolysis device for municipal waste, etc., according to an embodiment of the present invention, in which a feeding device 2 for pyrolysis raw materials such as municipal waste, etc. is attached above a fluidized bed furnace 1. . A gas chamber 8 is formed in the lower part of the fluidized furnace through a gas distribution plate 7, and heat is supplied to the gas chamber 8 by a burner 9.

A foreign matter extraction pipe 6 is attached to the center of the dispersion plate 7 to extract incombustible matter accumulated in the lower part of the fluidized bed.

On the other hand, a supply device 5 for supplying chir to the lower part of the fluidized bed is provided directly above the gas distribution plate 7 of the fluidized fluidized furnace 1, and the chir is fed by a screw feeder or the like. This chir supply device 5 and the upper part of the fluidized bed are connected by a passageway, that is, a communication pipe 4, and another passageway 12 in the upper part of the fluidized bed furnace.
The char in the pyrolysis gas released from the cyclone 3
is separated and returned to the supply device 5.

Next, the operation of this device will be explained.

Pyrolysis raw materials such as municipal waste are fed into the fluidized bed furnace 1 from the supply device 2 and are pyrolyzed in the fluidized bed.
At this time, a fluidizing gas containing oxygen necessary for combustion of the char is introduced into the gas chamber 8 to fluidize the char. If the amount of heat required for pyrolysis cannot be supplied by combustion of the char alone, fuel and combustion air are sent to the burner 9 to supply the amount of heat to the fluidized bed.

The gas generated by the thermal decomposition is mixed with the gas burned in the lower part and sent to the cyclone 3 from the passage 12, and after separating the entrained chia, it is recovered as a medium calorie gas.

Char and some of the fluidized particles that stay in the upper part of the fluidized bed due to the difference in specific gravity pass through the connecting pipe 4, are mixed with the chir collected by the cyclone 3, and are supplied into the fluidized bed from the lower part of the fluidized furnace 1 by the chir supply device 5. and burn. Incombustibles and coarse particles generated at this time are discharged from the foreign matter extraction pipe 6.

Next, in another embodiment of the present invention shown in FIG. 2, a chir combustion chamber 10 is provided between the fluidized fluidized furnace 1 and the chiar supply device 5.

The chir supplied from the chiar supply device 5 is given residence time and oxygen necessary for combustion in the chir combustion chamber 10, and is combusted.

In yet another embodiment of the present invention shown in FIG. 3, partition walls 11 are provided in the fluidized fluidized furnace 1 to form a moving bed. The chare and some of the fluidized particles staying in the upper part of the fluidized bed are introduced into the lower part of the fluidized bed by a moving bed formed by blocking the fluidizing gas with the partition wall 11, and the char is combusted. Therefore, in this embodiment, the connecting pipe 4 used in the previous embodiment can be omitted.

The method of forming a moving bed inside the fluidized bed is as follows:
It is not limited to what is illustrated.

As described above, the present invention achieves combustion of the char in the same fluidized bed as pyrolysis by forcibly supplying all of the char remaining in the upper part of the fluidized bed and the char separated from the generated gas to the lower part of the fluidized bed. This makes it possible to reduce the size of the device.

Furthermore, by providing a small chamber for burning the char, it is possible to provide the residence time necessary for burning the char without making the fluidized bed deep, and by providing a partition inside the fluidized bed, it is possible to provide a connecting pipe. In addition, it exhibits effects such as being able to introduce the char staying in the upper part of the fluidized bed to the lower part of the fluidized bed.

As described above, the present invention can also be applied to a so-called spouted furnace, and it is therefore clear that the term "fluidized bed" in this specification also includes a spouted bed.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, FIG. 2 is a sectional view of main parts showing another embodiment of the present invention, and FIG.
The figure is a sectional view of essential parts showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Fluidized fluid furnace, 2... Pyrolysis raw material supply device, 3... Cyclone, 4... Connecting pipe, 5... Supply device for combustible solid pyrolysis residue, 6... Foreign matter extraction pipe, 7... Gas distribution plate, 8... Gas Chamber, 9... Burner, 10... Combustion chamber, 11... Partition wall.

Claims (1)

[Scope of Claims] 1. In a fluidized bed type pyrolysis device for recovering combustible pyrolysis gas by pyrolyzing organic matter such as municipal waste, a pyrolysis raw material supplying device for supplying pyrolysis raw materials to a flow path is provided. A passage for collecting the flammable solid pyrolysis residue remaining in the upper part of the fluidized bed and another passage for separating and recovering the flammable solid pyrolysis residue from the pyrolysis gas are provided, and the residue collected from the other passage is A fluidized bed characterized in that a screw feeder is provided directly above a gas distribution plate provided at the bottom of the fluidized bed, and a supply section is further provided to supply a fluidizing gas containing oxygen for combustion to the fluidized bed. type pyrolysis equipment. 2. The fluidized bed pyrolysis apparatus according to claim 1, wherein the other passage is a connecting pipe outside the furnace that connects the upper part of the fluidized bed and the screw feeder. 3. The fluidized bed pyrolysis apparatus according to claim 1 or 2, characterized in that a moving bed is formed inside the fluidized furnace. 4. The fluidized bed pyrolysis apparatus according to any one of claims 1 to 3, characterized in that a combustion chamber is provided between the fluidized bed and the combustible solid pyrolysis residue supply device. .