JP2008002753A - Waste heat-treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste heat-treatment device capable of efficiently drying waste prior to heat treatment without increasing a size of the device. <P>SOLUTION: In this waste heat-treatment device having a furnace main body 1 performing heat treatment of waste, and a charging chute 2 for charging the waste into the furnace main body 1, the charging chute 2 has a jacket 8 for circulating a high-temperature gas, and a suction device 11 disposed at an upper position with respect to the jacket 8, and sucking and discharging the air in the charging chute 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat treatment apparatus for incinerating or melting waste.

  A waste heat treatment apparatus, for example, a waste incinerator for incinerating waste such as municipal waste, generally drops the waste from an input chute and supplies it into the incinerator and also supplies combustion air in the incinerator. The waste is incinerated. In many cases, the exhaust gas discharged from the incinerator is recovered by a waste heat boiler and used for steam turbine power generation.

  When sludge and other waste containing a lot of water are mixed with municipal waste and other general waste for combustion, are they dried by a dryer before supplying the sludge or sludge to the incinerator for smooth combustion? Alternatively, in the case of a grate-type incinerator, it was necessary to increase the area of the dry grate.

  Also, depending on the type of garbage, there are garbage with a lot of moisture, that is, those with low garbage quality (unit calorie of garbage as fuel). When burning such garbage with low garbage quality, In order to perform smooth combustion while maintaining the temperature at a predetermined temperature or higher, it was necessary to burn kerosene or the like using an auxiliary burner.

  In addition, when burning low-quality garbage, there is a problem that the amount of heat generation becomes low and the power generation amount decreases.

  In order to deal with such problems, Patent Document 1 proposes an incineration facility for drying garbage in a garbage pit.

  In the garbage incineration facility of Patent Document 1, a high-temperature water circulation channel is provided on the wall surface of the garbage pit storing the garbage before being put into the incinerator, and high-temperature water is allowed to flow there, so that the garbage is disposed in the incinerator. Prior to incineration, heating is performed in advance to reduce moisture in the garbage.

The high-temperature water is high-temperature water generated in a waste heat boiler using waste gas obtained by incineration of garbage, and this is supplied to the high-temperature water circulation channel.
JP-A-8-100915

  However, in the incineration facility in Patent Document 1, since the garbage pits are thrown in one after another from the garbage truck and a large amount of garbage is stored, the humidity in the garbage pit becomes very high due to the water evaporated from the heated garbage, There have been problems such as frequent failure of a garbage crane or the like provided above the garbage pit opened upward, and corrosion of the steel pit of the garbage pit due to condensation.

  Further, since the dust pit has a large capacity and only the dust near the wall surface is heated by the high temperature water, there is a problem that the dust in the center of the dust pit is insufficiently reduced in moisture.

  Furthermore, the moisture content of garbage varies greatly depending on the weather, season, or collection location. Therefore, the moisture content of garbage may be extremely low from the beginning. Due to heat transfer from the furnace, ignition may occur in the charging chute, and the incineration facility of Patent Document 1 cannot cope with such a problem.

  This invention makes it a subject to provide the waste heat processing apparatus which dries a waste efficiently prior to heat processing, without enlarging an apparatus in view of this situation.

  The waste heat treatment apparatus according to the present invention includes a furnace main body that performs heat treatment of waste, and an input chute for introducing the waste into the furnace main body.

  In such a waste heat treatment apparatus, in the present invention, the input chute has a jacket through which high-temperature gas flows, and a suction device that is provided at a position higher than the jacket and sucks and discharges air in the input chute. It is characterized by.

  In the present invention having such a configuration, the waste is put into the charging chute by an amount to be heat-treated from the garbage pit, and is heated by the jacket in the charging chute immediately before the heat treatment to reduce moisture. The moisture evaporated from the waste heated in the charging chute and the generated odor gas are taken out of the charging chute by a suction device provided above the jacket.

  In the present invention, the jacket is preferably provided on the peripheral surface of the charging chute, and the installation position may be the inner peripheral surface or the outer peripheral surface of the charging chute.

  In the present invention, the suction device is connected to a combustion air supply unit provided in the furnace body, and can supply the air sucked from the charging chute as a part of the combustion air. Air containing moisture and odorous gas sucked from the charging chute by the suction device is supplied to the furnace body as part of the combustion air without being released to the atmosphere.

  In the present invention, the suction device is preferably connected to the combustion air supply unit via a dehumidifying device. When the air sucked from the input chute contains excessive moisture, it is dehumidified by the dehumidifier and then supplied to the furnace body as part of the combustion air.

  In the present invention, it is preferable that the jacket is connected to the furnace main body cooling device and introduces high-temperature air after the furnace main body is cooled into the jacket. Thereby, the heat of the high-temperature air obtained by cooling the furnace body can be effectively used for heating the waste with the charging chute.

  Further, according to the present invention, the jacket has an air supply portion for introducing the high temperature gas into the jacket, and an exhaust portion for discharging the high temperature gas to the outside of the jacket after circulation in the jacket. It is preferable to have a switching valve that switches between introduction of gas and introduction of room temperature air from the atmosphere.

  In addition, some of the wastes have a very low moisture content. In this case, in order to prevent the waste in the charging chute from being excessively dried, the waste introduced into the jacket is replaced with hot air from room temperature air. To prevent the waste from igniting in the charging chute by heat transfer from the furnace body.

  The present invention is applicable to a waste heat treatment apparatus such as a waste incinerator or a waste melting furnace.

  As described above, the present invention provides a charging chute for charging waste with a jacket for circulating a high-temperature gas and a suction device for sucking and discharging the air in the charging chute above the charging chute. Therefore, the waste can be heated and dried immediately before heat treatment. As a result, it is not necessary to use an auxiliary burner when heat-treating waste with a lot of moisture, and because the waste is heated with an input chute that is part of the furnace, there is no need for equipment to be dried in advance other than the furnace. Increase in size can be prevented.

  Moreover, since it can heat and dry sequentially according to the quality and quantity of the heat-processed waste, the electric power generation amount using the waste heat which heat-processed the waste can be increased. Furthermore, moisture and odor gas generated from the waste are not released to the outside.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1A is a schematic configuration diagram of a waste incinerator as an example of the waste heat treatment apparatus of the present invention, and FIG. 1B is an enlarged sectional view taken along line BB in FIG. .

  In FIG. 1 (A), the furnace body 1 is provided with a charging chute 2 for charging waste to be incinerated. Usually, the charging chute 2 is adjacent to a garbage pit (not shown) in which waste collected from each household is stored, and reciprocates between the garbage pit and the charging chute 2 between them. A crane is provided, and the waste P is appropriately picked up from the garbage pit by a bucket suspended from the crane and is put into the charging chute 2.

  Three grates 3, 4, 5 to be inclined are sequentially provided at the lower part of the furnace body 1, and combustion air supply units 3 A, 4 A- 1 and 4 A- 2, 5 A forming a wind box are provided below them. Are provided. The three grates 3, 4, and 5 are sequentially positioned below to form a dry grate, a combustion grate, and a post-combustion grate, and transport the waste P on the grate downstream while burning it.

  At the downstream end of the furnace body 1, an ash chute 6 that opens at the bottom and a secondary combustion chamber 7 that opens at the top are provided. In the secondary combustion chamber 7, unburned gas in the exhaust gas is burned, and the exhaust gas is sent to a waste heat boiler (not shown). In the waste heat boiler, steam is generated using the waste heat of the high-temperature exhaust gas, and the steam is supplied to the power generation turbine. Further, the waste heat boiler is connected to a processing facility where the exhaust gas is detoxified, and further to a chimney that releases the detoxified gas to the atmosphere. The ash chute 6 discharges ash from the post-combustion grate 5 to the outside.

  In the present invention, a jacket 8 is provided on the outer periphery of the charging chute 2 of the furnace body 1. In this embodiment, the jacket 8 has a rectangular tube so as to surround the outer peripheral surface of the charging chute 2 and forms an annular space inside. As shown in FIG. A plurality of fins 2 </ b> A extending from the outer surface of the chute 2 are accommodated. A lower portion of the jacket 8 is provided with an air supply portion 8A that receives a supply of high-temperature gas from the outside, and an upper portion is provided with an exhaust portion 8B that is discharged after the high-temperature gas flows through the jacket 8.

  The air supply unit 8A is provided with a switching valve 9, and one of the two pipe lines 10A and 10B communicates with the air supply unit 8A. One pipe line 10A is a high-temperature gas supply pipe, and the other pipe line 10B is a room temperature air supply pipe. The high-temperature gas supply pipe 10A can receive high-temperature gas from various high-temperature gas sources, and supplies, for example, high-temperature air obtained by cooling the furnace body or high-temperature exhaust gas. The room temperature air supply pipe 10B supplies room temperature air in the atmosphere.

  Above the jacket 8, the hopper 2A of the charging chute 2 is provided with a suction part 11A of the suction device 11. The suction part 11A is formed by attaching holes (not shown) on, for example, three wall surfaces of the hopper 2A and attaching a rectangular body so as to form a space around the hole. Since dust is generated when the waste P is thrown into the charging chute 2 from the garbage pit by the crane, the suction portion 11A is placed above the upper surface of the waste P so that the hole of the suction portion 11A is not clogged. To be provided.

  A pipe line 11B is connected to the suction part 11A. The pipe line 11B passes through a dehumidifier 11C and a blower 11D, and then supplies each of the combustion air supply parts 3A, 4A-1, 4A-2, Branched to 5A and connected. Thus, the suction device 11 is formed by the suction portion 11A, the pipe line 11B, the dehumidifying device 11C, and the blower 11D, and after the air in the input chute 2 is dehumidified, the combustion air supply portions 3A, 4A-1, 4A-2. , 5A. In the combustion air supply units 3A, 4A-1, 4A-2, and 5A, not only the air from the suction unit 11A but also air from the outside is supplied together.

  In the waste incinerator of this embodiment having such a configuration, the waste P is processed in the following manner.

  (1) First, waste P such as household garbage containing a large amount of moisture is dropped into the charging chute 2 from a garbage pit by a crane or the like. This input amount is appropriately determined according to the waste disposal capacity in the furnace body 1. The waste P is accumulated in the charging chute 2 to a position slightly above the jacket 8. The waste P is sent out from the input chute 2 to the dry grate 3 by a supply device (not shown).

  (2) The switching valve 9 is switched so that the pipe line 10A communicates with the air supply part 8A of the jacket 8, and high-temperature gas flows into and flows through the jacket 8 and is discharged from the exhaust part 8B. Due to this high-temperature gas, the waste P in the input chute 2 is heated through the wall surface of the input chute 2 to become low moisture, and the water evaporated from the waste P rises in the input chute 2.

  (3) Moisture and odor gas evaporated from the waste P are taken out of the charging chute 2 together with the air in the charging chute 2 by the suction device 11 and dehumidified by the dehumidifying device 11C of the suction device 11, and then from the outside. Together with the air, it is supplied as combustion air to the combustion air supply units 3A, 4A-1, 4A-2, 5A.

  (4) On the grates 3, 4, 5, the waste P is incinerated by receiving the air from the combustion air supply units 3 </ b> A, 4 </ b> A- 1, 4 </ b> A- 2, 5 </ b> A from below. First, the waste P is sufficiently dried on the dry grate 3, starts to burn on the combustion grate 4, and post-combusts on the post-combustion grate 5.

  (5) The ash content of the waste P that has been combusted is discharged from the ash chute 6 to the outside of the system. The exhaust gas is guided from the secondary combustion chamber 7 to the waste heat boiler and used to generate steam for power generation in the steam turbine, and then detoxified by the detoxification equipment and discharged from the chimney to the atmosphere.

  (6) Moreover, when the water content of the waste P is sufficiently low, the waste P may be heated and ignited by heat transfer from the incinerator in the charging chute 2. In that case, the switching valve 9 is switched to the pipe line 10B, and normal temperature air is allowed to flow into the jacket 8 from the atmosphere so that the waste P in the charging chute 2 is excessively dried. Suppress.

  Further, when the water vapor or mist generated from the waste P in the input chute 2 is small, the dehumidifying device 11C of the suction device 11 may be omitted. The air containing water vapor and mist generated from the waste P is supplied as combustion air to the furnace body 1 together with air from the outside. However, in this case, the influence of water vapor and mist on waste combustion is small. It doesn't matter.

  The present invention is not limited to the illustrated embodiment, and various modifications can be made. For example, the type of the furnace body itself of the incinerator may be a fluidized bed type, a kiln type or the like instead of the stoker type having the illustrated grate. The present invention can be applied not only to incinerators but also to other waste heat treatment apparatuses such as a direct melting type or low temperature gasification melting type waste melting furnace.

1 shows an apparatus according to an embodiment of the present invention, (A) is a schematic configuration diagram, and (B) is an enlarged cross-sectional view taken along line BB in (A).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Furnace body 2 Input chute 3A, 4A-1, 4A-2, 5A Combustion air supply part 8 Jacket 8A Air supply part 8B Exhaust part 9 Switching valve 11 Suction apparatus 11C Dehumidifier

Claims (5)

  In a waste heat treatment apparatus having a furnace body that performs heat treatment of waste and an input chute for introducing waste into the furnace body, the input chute includes a jacket through which high-temperature gas circulates and a position above the jacket A waste heat treatment apparatus comprising a suction device that is provided at a position and sucks and discharges air in a charging chute.   The suction device is connected to a combustion air supply section provided in the furnace body, and supplies the air sucked from the charging chute as a part of the combustion air. The waste heat treatment apparatus as described.   The waste heat treatment apparatus according to claim 2, wherein the suction device is connected to the combustion air supply unit via a dehumidifying device.   The jacket is connected to the furnace body cooling device, and introduces high-temperature air after cooling of the furnace body into the jacket. Waste heat treatment equipment.   The jacket has an air supply section for introducing the high temperature gas into the jacket and an exhaust section for discharging the high temperature gas outside the jacket after circulation in the jacket. The waste heat treatment apparatus according to any one of claims 1 to 4, further comprising a switching valve that switches between introduction of room temperature air.

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