JPH11173518A - Device and method for treating waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for treating waste by which production of dioxin can be suppressed and incinerated ash can be treated by melting, and then, harmful wastes can be treated and valuable materials can be recycled and which are suitable for small-sized incinerators. SOLUTION: A first oxygen burner 2 for heating wastes and a second oxygen burner 3 for heating granular substances, as the dust, etc., are provided in the bottom section of a treating incinerator 1. The dust, etc., contained in the exhaust gas from the incinerator 1 is collected by means of a dust collector 10 and, after valuable materials are separated from the dust, etc., the dust, etc., are melted by throwing the dust, etc., in the flame of the second oxygen burner 3. Part of the exhaust gas is used as the fuel of the oxygen burners 2 and 3 and the balance of the gas is secondarily burnt in a boiler 9 to produce steam. The steam is used to generate the electric power which used to drive an air separator 18. Wastes are charged in the incinerator 1 from different position in accordance with their characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus and a method for treating waste, and more particularly to an apparatus and a method for heating, melting and gasifying various kinds of waste by using an oxygen burner.

[0002]

2. Description of the Related Art Various types of refuse incinerators are used, and small incinerators with a daily throughput of 100 tons or less, for example,
Stalker-type incinerators, fluidized-bed incinerators, and the like have problems such as suppression of dioxin generation and treatment of incineration ash.
Incineration ash is generally melted in an arc melting furnace, a resistance heating furnace, or a plasma melting furnace, but has a large cost problem.

On the other hand, large-scale incinerators with a daily throughput of over 100 tons can be used for gasifying and melting furnaces that can also incinerate incineration ash and generate electricity with the energy obtained by gasifying and converting waste into fuel. Melting furnaces are in the limelight, and there is a move from small incinerators to large incinerators.

[0004] However, in the case of a large incinerator, not only is the equipment configuration complicated and the equipment cost is large, but also it is necessary to collect a large amount of waste from a wide area, and the amount of energy consumed for this collection is large. Is also a great deal, which is not a good idea.

Accordingly, the present invention provides a small incinerator,
As with large gasification and melting furnaces, a waste disposal system and method that can control the generation of dioxins, melt incineration ash and fly ash, treat hazardous waste, and recycle valuable materials. It is intended to provide.

[0006]

In order to achieve the above object, a waste treatment apparatus of the present invention is provided with a first oxygen burner for heating waste at a lower portion of a vertical treatment furnace. A second oxygen burner for heating powder or other particulate matter generated from the processing furnace, further comprising dust contained in exhaust gas discharged from the processing furnace. A dust collecting device for collecting the powdery material, a valuable material separating device for separating and collecting the valuable material in the powdery material collected by the dust collecting device, and a powdery material after separating the valuable material into the second material. A boiler for secondary combustion of exhaust gas discharged from the processing furnace to generate high-temperature and high-pressure steam, and a steam generated by the boiler. Power generation equipment as a power source, and An air separation device that generates oxygen to be supplied to the oxygen burner using the generated power as a power source, and a path for supplying a part of exhaust gas discharged from the processing furnace as fuel for the oxygen burner. It is characterized by having.

Further, in the method for treating waste according to the present invention, when treating waste using the above-described apparatus, the waste to be treated is separated into the upper part or the lower part of the treatment furnace or the lower part according to its characteristics. It is characterized in that it is introduced into the processing furnace from either the first oxygen burner or the second oxygen burner.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic system diagram showing one embodiment of a waste disposal apparatus according to the present invention. The waste disposal apparatus shown in this embodiment is for incineration of general waste such as municipal waste, and the lower part of a vertical processing furnace 1 heats combustible waste as waste. First for gasification
An oxygen burner 2 and a second oxygen burner 3 for heating and fusing powders such as dust generated in the processing furnace 1 on a lower side of the furnace than the first oxygen burner 2 are provided. Is provided with a waste input path 4 and an exhaust gas path 5.

The two oxygen burners 2 and 3 are provided with oxygen paths 6 and 6 respectively.
a, a high-temperature flame is formed by burning a fuel mainly using oxygen supplied from a, 6b, that is, oxygen-enriched air or pure oxygen as a supporting gas. , 7a and 7b supply fuel such as gaseous fuel, liquid fuel, solid fuel or waste oil to both oxygen burners 2 and 3, respectively. Further, a part of the exhaust gas discharged from the processing furnace 1 can be supplied as gasified fuel to both the oxygen burners 2 and 3 via the gasified fuel path 8 branched from the exhaust gas path 5.

In the exhaust gas path 5, a combustible component such as hydrogen or carbon monoxide generated by a gasification reaction in the processing furnace 1 is burned (secondary combustion) by air supplied from a path 9a, and is subjected to high temperature and high pressure. Boiler 9 for generating steam, high-temperature type dust collector 10 for separating and recovering powder and particulate matter such as dust and fly ash contained in exhaust gas after secondary combustion, and exhaust gas after particulate matter separation Exhaust gas treatment device 11 for removing harmful components such as sulfur oxides and nitrogen oxides in the gas and discharge route 12
Are provided.

Further, the powder material recovery path 13 of the dust collector 10
The valuable material separating device 14 for separating the valuable material contained in the collected granules, the path 15 for collecting the separated valuable material, and the granules after separating the valuable material (2) Route 1 for injection into flame of oxygen burner 3
6 are provided.

Further, there are provided a power generation facility 17 for generating power using high-temperature and high-pressure steam generated in the boiler 9 and an air separation device 18 for generating oxygen using the power generated in the power generation facility 17 as a power source. Have been. As the air separation device 18, a device that separates and recovers oxygen in the air by the pressure fluctuation adsorption method, that is, an oxygen PSA or the like can be used. Is used as a power source for a vacuum pump and a compressor provided in the air separation device 18. The oxygen or oxygen-enriched air generated in the air separation device 18 is supplied to both oxygen burners 2 and 3 through the oxygen path 6.

In the waste treatment apparatus thus formed, general waste is continuously or intermittently introduced into the furnace from the waste introduction path 4 at the upper part of the processing furnace. The waste introduced into the furnace is mainly heated by the high-temperature combustion gas from the first oxygen burner 2 to partially burn and gasify, and hydrogen and carbon monoxide generated by the decomposition of hydrocarbons are generated. A combustible gas (gasified gas) containing is generated. The gasified gas is introduced from the processing furnace 1 into the boiler 9 via the exhaust gas path 5, and a part of the gas is branched into the gasified fuel path 8 and the oxygen burners 2, 3
Supplied to Further, in the lower part of the processing furnace 1, the incombustible component in the waste, that is, incineration ash is heated and melted by the flame of the first oxygen burner 2, and furthermore, the incineration ash in a molten state or a semi-molten state flowing down to the furnace bottom is Is completely melted by the flame of the second oxygen burner 3.

At this time, the use of an oxygen burner as a heating source in the processing furnace 1 makes it possible to greatly reduce the amount of nitrogen in the gasified gas as compared with a case where a general air burner is used. Furthermore, since the waste is not burned by blowing air or oxygen into the processing furnace, the amount of carbon dioxide in the gasified gas discharged from the processing furnace 1 is small, and it can be used as a high-quality fuel gas.

For example, in the case of general waste, the calorific value is
It is 2000 kcal / kg and contains 12% ash and 50% moisture. When this is heated to a high temperature to cause a gasification reaction, a gas having a composition of 17% of hydrogen, 22% of carbon monoxide, 11% of carbon dioxide and 49% of moisture and having a calorific value per 1 Nm ³ (true calorific value) of 2,200 kcal is obtained. Chemical gas 0.6
4 Nm ³ (calorific value 1400 kcal) is generated.

The gasified gas discharged from the processing furnace 1 to the exhaust gas path 5 reacts with oxygen in the air supplied from the path 9a in the boiler 9 to perform secondary combustion to generate high-temperature and high-pressure steam. . The combustion temperature at this time becomes 1200 ° C. or more due to the sensible heat and latent heat of the gasification gas, and an environment in which dioxin is completely burned is formed.

The exhaust gas in which the combustible components and the soot (carbon) in the dust are converted into carbon dioxide or water by the secondary combustion in the boiler 9 is subjected to dust removal by a dust collector 10 after the dust or the like is removed. Then, while being quenched by the exhaust gas treatment device 11, harmful components such as SOX and NOX are removed by neutralization treatment with calcium hydroxide or the like, and the exhaust gas is released into the atmosphere from the passage 12 as clean exhaust gas.

On the other hand, the powdery material separated and recovered by the dust collecting device 10 is subjected to a valuable material separating process by a valuable material separating device 14. That is, the exhaust gas (gasified gas) discharged from the processing furnace 1 contains valuable materials such as metals having a relatively low melting point, such as zinc and lead, and these valuable materials are contained in the dust collector. At 10, the valuable material is separated from the exhaust gas together with other dusts and the like, so that the valuable material separating device 14 separates the valuable material by a difference in specific gravity or the like, and sends the valuable material to the path 15 for recycling. The powdery material after the separation of the valuable material is introduced into the flame of the second oxygen burner 3 from the path 16 to perform a melting process. The method of introducing the granules into the flame of the second oxygen burner 3 is arbitrary. For example, a general thermal spray burner is used for the second oxygen burner 3, and a part of oxygen is used as a carrier gas for the granules. You only have to transport your body. The melted incombustible material is taken out from the path 19 at the bottom of the furnace, and after being subjected to processing such as cooling and solidification and pulverization, it can be reused as aggregate or the like.

The high-temperature and high-pressure steam generated in the boiler 9 is introduced into a power generation facility 17 to drive a steam turbine, and the steam turbine drives a generator to generate electric power. Further, the power generated by the power generation equipment 17 is
The air is supplied to the air separation device 18 and is used as a power source of a vacuum pump installed in a PSA device for generating oxygen.

Here, in the case of treating the above-mentioned general waste, in order to heat the waste to a high temperature to cause a gasification reaction,
It is necessary to supply 0.27 Nm ³ of oxygen per kg of refuse to the oxygen burner to burn fuel. In addition, incineration ash, which is a non-combustible component, is generated at 0.12 kg per 1 kg of garbage, and the amount of oxygen required to melt it is 0.03 kg.
A Nm ^3. Therefore, 0.3N / kg of waste
requires a oxygen m ^3, the power (electric power) required to generate oxygen for the 0.3 Nm ³ in the general oxygen PSA is about 0.15 kW, the gasification gas 0.6
Assuming that the total efficiency of steam turbine power generation using high-temperature and high-pressure steam generated by combustion of 4 Nm ³ (calorific value of 1400 kcal) is 15%, the generated power is 0.24 kW, and it is possible to obtain power more than necessary for generating oxygen. it can.

The surplus electric power may be supplied to other equipment, but a part of the gasified gas is branched from the exhaust gas path 5 to the gasified fuel path 8 and used as fuel for the oxygen burners 2 and 3. Alternatively, the amount of combustion in the boiler 9 may be reduced to adjust the amount of power. In this way, by using a part of the gasified gas as fuel for the oxygen burners 2 and 3, the amount of fuel supplied from the fuel path 7 can be reduced, and fuel cost can be reduced.

As described above, the lower part of the processing furnace 1 is formed by using oxygen or oxygen-enriched air as a combustion supporting gas.
By installing the first and second oxygen burners 2 and 3 that can obtain a high-temperature flame of 0 ° C. or more, burn refuse with high-temperature combustion gas generated from both oxygen burners, particularly the first oxygen burner 2. The gasification reaction can be performed by heating without heating, so that a gasified gas useful as a fuel can be efficiently obtained, and the secondary combustion in the boiler 9 enables complete combustion of dioxin, By using the fuel for the first and second oxygen burners 2 and 3, the energy of the refuse can be effectively utilized. Further, incineration ash generated in the furnace and dropped to the lower part of the furnace and dust and fly ash separated and recovered from the exhaust gas can be heated and melted by the high-temperature flame of the second oxygen burner 3, so that another treatment is performed. There is no need to perform a melting process in the equipment, and the processing cost can be significantly reduced.

[0023] Therefore, the lower part of the vertical processing furnace 1 for treating waste is provided with a first waste heating and gasification furnace.
By providing the oxygen burner 2 and the second oxygen burner 3 for heating and melting the dust and fly ash generated from the processing furnace 1, even in a small incinerator, a large gasification and melting furnace can be used. Similarly, dioxin generation can be suppressed and incineration ash can be melted.

Further, dust and fly ash in the exhaust gas are collected by a dust collector 10 and valuable materials are separated by a valuable material separator 14 and then put into the flame of the second oxygen burner 3. Thereby, the melting process of the recovered powder can be efficiently performed in the system, and the valuable material can be recycled.

Further, by using the secondary combustion energy of the gas discharged from the processing furnace 1 as power for generating oxygen in the air separation device 18 via the boiler 9 and the power generation equipment 17, both oxygen burners 2, 3 can be used. Can be obtained in the system.

The powder or particulate matter such as dust and fly ash contained in the exhaust gas may be subjected to a melting treatment or the like in another facility after collection, and the secondary combustion energy of the exhaust gas may be used for other purposes, for example, in hot water. You may make it use for supply etc.

In the present invention, the processing furnace 1, the oxygen burners 2 and 3, the boiler 9, the dust collecting device 10, the exhaust gas processing device 11, the valuable material separating device 14,
As the power generation equipment 17 and the air separation device 18, those having various configurations conventionally used in the related art can be used in accordance with the processing amounts, and are not particularly limited. I do.

FIG. 2 shows an embodiment in which the present invention is applied to the treatment of industrial waste. Note that the same components as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In the processing apparatus of the present embodiment, the first charging path 21 in the upper part of the processing furnace, the second charging path 22 in the lower part of the processing furnace, and the two oxygen burners 2 and 3 Third charging path 2 for charging as fuel
3 and a fourth charging path for charging into the flame of the second oxygen burner 3.

The waste put into each charging route is determined according to the characteristics of each waste. For example, construction waste, which is a waste having good gas permeability and no shelving,
Metal scraps, glass and pottery scraps, mining tails, cinders,
It is charged into the processing furnace 1 from the first charging path 21 in the upper part of the processing furnace. In addition, dumped incineration ash, which is waste that contains harmful evaporates, has poor gas permeability, and has shelf suspendability,
Contaminated soil, specified CFCs, semiconductor substrates, sludge, sludge,
Waste asbestos and the like are charged from the second charging path 22 below the processing furnace. Combustible waste, for example, waste oil, powdery plastic, powdery biomass, dry sewage sludge, and the like are input from the third input path 23, and dust, fly ash, dust, and nonflammable waste liquid are input from the fourth input path. (Including waste acid and waste alkali)
Etc. are input.

When the amount of combustible waste to be charged from the third charging path 23 is sufficient, the fuel path can be omitted. However, the amount of combustible waste is small and it is necessary to provide a fuel path. If there is, the third charging path 23 may be used also as a fuel path, or both paths may be joined at the oxygen burner inlet. When a sufficient amount of gasified gas can be obtained, a gasified fuel path similar to the above can be provided. Further, as shown in FIG. 2, the fourth charging path may be combined with a path 16 for charging the powder and granules generated and recovered in the system into the flame of the second oxygen burner 3. Good. In addition, both oxygen burners 2, 3
Are provided, a plurality of routes can be appropriately distributed.

As described above, the waste to be treated is put into the treatment furnace 1 from a position corresponding to its characteristics, so that each waste including harmful substances can be efficiently decomposed, burned or burned in a single treatment furnace. Can be melted.

[0032]

As described above, the waste treatment apparatus and method of the present invention treat waste with a high-temperature flame obtained by an oxygen burner, thereby suppressing the generation of dioxins and melting of incinerated ash. Can be performed in a single processing furnace,
Very suitable for small incinerators. In addition, valuable materials can be recovered, and power for generating oxygen can be obtained by using secondary combustion energy of exhaust gas (gasified gas). Further, part of the gasified gas can be used as fuel for the oxygen burner. Therefore, waste treatment can be performed efficiently at low cost. In particular, by throwing waste into the processing furnace from a position corresponding to the characteristics of the waste, harmful substances can be efficiently processed and the energy of the waste can be efficiently used.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram showing one embodiment of a waste treatment apparatus according to the present invention.

FIG. 2 is a schematic system diagram of a waste treatment apparatus showing another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Processing furnace, 2 ... 1st oxygen burner, 3 ... 2nd oxygen burner, 4 ... Waste supply path, 5 ... Exhaust gas path, 6 ... Oxygen path, 7 ... Fuel path, 8 ... Gasification fuel path, 9 ... Boiler, 10: Dust collection device, 11: Exhaust gas treatment device, 13: Powder and particulate material recovery path, 14: Valuable material separation device, 17: Power generation equipment, 18: Air separation device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F23G 5/14 ZAB F23G 5/14 ZABG 5/44 ZAB 5/44 ZABB 5/46 ZAB 5/46 ZABZ F23L 7/00 F23L 7 / 00 A (72) Inventor Koji Seki Inside Nippon Sanso Corporation, 1-16-7 Nishi-Shimbashi, Minato-ku, Tokyo

Claims (5)

[Claims] A first oxygen burner for heating waste is provided at a lower portion of a vertical processing furnace, and a second oxygen burner is provided for heating powder and other particulates generated from the processing furnace.
Waste treatment apparatus characterized by including an oxygen burner. 2. A dust collecting device for collecting dust and the like contained in exhaust gas discharged from the processing furnace, and a valuable material for separating and collecting valuable materials in the powder and granules collected by the dust collecting device. The waste treatment apparatus according to claim 1, further comprising: a material separation device; and a path for introducing the granular material after separating the valuable material into the flame of the second oxygen burner. 3. A boiler for secondary-burning exhaust gas discharged from the processing furnace to generate high-temperature and high-pressure steam, a power generation facility using the steam generated by the boiler as a power source, and a power generation facility generated by the power generation facility. The waste treatment apparatus according to claim 1 or 2, further comprising an air separation device that generates oxygen to be supplied to the oxygen burner using electric power as a power source. 4. A waste treatment apparatus according to claim 1, further comprising a path for supplying a part of the exhaust gas discharged from the treatment furnace as fuel for the oxygen burner. . 5. A waste treatment method using the waste treatment apparatus according to claim 1, 2, 3, or 4, wherein the waste to be treated is placed in an upper part of the treatment furnace according to its characteristics. Alternatively, a method for treating waste, wherein the waste is charged into a processing furnace from a lower portion or any one of the first oxygen burner and the second oxygen burner.