WO2000017289A1

WO2000017289A1 - Wastes incineration disposal method

Info

Publication number: WO2000017289A1
Application number: PCT/JP1999/005016
Authority: WO
Inventors: Masamoto Kaneko
Original assignee: Kinsei Sangyo Co., Ltd.
Priority date: 1998-09-22
Filing date: 1999-09-14
Publication date: 2000-03-30
Also published as: JP4005770B2; CN1213128C; KR100566180B1; CN1315992A; KR20010075175A

Abstract

An incineration disposal method for wastes for preventing PCDDs emission and shortening a disposal cycle, wherein wastes are dry-distilled in a gasification furnace and a combustible gas generated is burned in a combustion furnace. Oxygen is supplied to the combustion furnace according to the volume of the combustible gas, while an oxygen volume supplied to the gasification furnace is controlled according to a change in combustion gas combustion temperature so as to regulate the production volume of the combustible gas to keep a combustion furnace temperature at approximately constant one higher than a preset temperature. When a gasification furnace temperature lowers from a maximum temperature to below a PCDDs production temperature after a combustion furnace temperature falls to below the approximately constant temperature, burned residues are immediately taken out from the gasification furnace. Alternatively, while a gasification furnace temperature is falling from the maximum temperature, burned residues are housed in a fusion furnace connected with the gasification furnace. Thereafter, new wastes are charged into the gasification furnace and ignited. The burned residues are heated in the fusion furnace and molten matter is placed into water for quenching to thereby form granulated solid matter.

Description

Description Waste incineration method Technical field

The present invention relates to a method for incinerating waste. Background art

The present applicant has previously proposed, as an apparatus for incinerating waste such as waste tires, an apparatus disclosed in Japanese Patent Publication No. 135280/1990.

The apparatus disclosed in the above publication comprises a gasifier having a closed structure, and a combustion furnace connected to the gasifier through a gas passage, and burns a part of waste in the gasifier. In addition, combustible gas generated by carbonizing other parts of the waste with the combustion heat is introduced into the combustion furnace and completely burned. Next, the procedure of the waste incineration treatment by the above-described apparatus will be described in detail.

When the waste is incinerated by the above-described apparatus, the waste previously stored in the gasifier having a closed structure is ignited, and a part of the waste is burned. Part is carbonized. The combustible gas generated by the carbonization is introduced into a combustion furnace provided outside the gasification furnace via a gas passage. In the combustion furnace, the combustion of the combustible gas is started by supplying a combustion flame to the introduced combustible gas and igniting.

When the dry distillation in the gasification furnace proceeds and the combustible gas is generated stably, the amount of the combustible gas generated gradually increases, and accordingly, the temperature T in the combustion furnace increases. The combustion temperature of the combustible gas detected as ₂ rises one after another as shown in FIG. Therefore, if the temperature T ₂ in the combustion furnace, the combustible gas reaches the temperature T _2.beta can be continued spontaneously stable combustion by self combustion heat supply of the combustion flame To stop.

In the combustion furnace, oxygen necessary for complete combustion of the combustible gas is supplied into the combustion furnace according to the amount of the combustible gas introduced. At the same time, the flammable gas In a state where is completely burned, and detects the temperature tau of the combustion furnace as the combustion temperature of the combustible gas, by controlling the amount of oxygen supplied to the gasification furnace in accordance with a change in temperature tau ₂ The amount of the flammable gas generated by the dry distillation is adjusted. As a result, in the apparatus, the temperature τ ₂ in the combustion furnace can be maintained substantially constant at a temperature T _{2h equal} to or higher than the temperature T _2a at which the combustible gas spontaneously stabilizes and continues combustion.

In the apparatus, when the carbonization further progresses and the portion of the waste in the gasifier that can be carbonized decreases, even if the amount of oxygen supplied to the gasifier is increased, the temperature T ₂ can not be generated only in the combustible gas to maintain a substantially constant temperature T _2h. Then, the temperature τ ₂ in the combustion furnace gradually decreases, and in the gasification furnace, the carbonization and combustion of the waste are completed, and the waste is ashed. The temperature in the gasification furnace is shown in FIG.

As a result, according to the apparatus, dry distillation of the waste and complete combustion of the combustible gas can be stably performed. Waiting for the temperature 1 \ in the gasification furnace to become low enough to facilitate the handling of the ash, the ash is discharged from the gasification furnace, and the waste gas is newly disposed in the gasification furnace. By injecting a material and repeating the above procedure, the above procedure can be regarded as one cycle, and the waste incineration can be continuously performed.

However, in the above apparatus, since the ash in the gasification furnace is at a high temperature, the temperature 1 in the gasification furnace must be low enough to facilitate the handling of the ash. It takes a long time, and there is a disadvantage that the processing cycle becomes long. In recent years, it has been pointed out that dioxins are generated during incineration of waste. This is because the wastes often contain chlorine, and if such wastes are burned at a temperature of about 250 to 350 ° C, the chlorine released from the wastes And a hydrocarbon produced by incomplete combustion of a resin or the like, and a heavy metal contained in the waste reacts as a catalyst to produce dioxins. In order to prevent the emission of dioxins due to the incineration of the waste, it takes a long time to completely decompose the generated dioxins, Further, there is a disadvantage that the processing cycle becomes longer. Disclosure of the invention

An object of the present invention is to provide a method for incinerating waste which can prevent the discharge of dioxins and can shorten the processing cycle in order to solve such inconveniences.

In order to achieve the above object, a waste incineration method according to the present invention ignites waste stored in a gasification furnace to burn a part of the waste, and heats the waste with the heat of combustion. A step of carbonizing another portion; and a step of introducing a combustible gas generated by the carbonization into a combustion furnace and burning the combustible gas. Oxygen required for the combustion is supplied to the combustion furnace in accordance with the amount of the combustible gas to be introduced to burn the combustible gas, and the temperature in the combustion furnace due to the combustion of the combustible gas in the combustion furnace. The amount of oxygen supplied to the gasification furnace is controlled according to the change, the amount of combustible gas generated by the dry distillation is adjusted, and the temperature in the combustion furnace is maintained at a substantially constant temperature equal to or higher than a predetermined temperature. The present invention relates to the improvement of waste incineration methods. In a first aspect of the present invention, in the waste incineration method, a portion of the waste gas in the gasification furnace that can be carbonized decreases as the carbonization of the waste material in the gasification furnace progresses. Immediately after the temperature in the combustion furnace falls below the substantially constant temperature, when the temperature in the gasification furnace falls from the maximum temperature and falls below the temperature at which dioxins are produced from the waste. Removing the incineration residue from the gasification furnace; and removing the incineration residue from the gasification furnace, storing new waste in the gasification furnace and igniting the residue. Features.

The waste often contains chlorine, and if such waste is burned at a temperature of about 250 ° C. (about 350 ° C.), dioxins are generated as described above. Therefore, in the first aspect of the present invention, the portion of the waste gas in the gasification furnace that can be carbonized decreases with the progress of carbonization of the waste material in the gasification furnace. After the temperature in the inside cannot maintain a substantially constant temperature equal to or higher than the predetermined temperature, After the waste is in a direct combustion state and the temperature in the gasification furnace reaches the maximum temperature, it starts to decrease, and immediately when the temperature becomes lower than the temperature at which dioxins are generated from the waste, for example, the gasification furnace The incineration residue of the waste is removed from the gasification furnace when the temperature in the inside becomes about 200 ° C.

In doing so, it is possible to take out the incineration residue from the gasifier without waiting for the incineration residue to be sufficiently low in temperature, and to put new waste into the gasifier and ignite. The processing cycle can be shortened. In addition, since the new waste is introduced before the gasification furnace is cooled, the amount of heat required for the incineration can be reduced.

At the time of removing the incineration residue from the gasifier, the waste may have a portion that can be carbonized.However, since the temperature in the gasifier has decreased, dioxins are generated. Without this, dioxins can be prevented from leaking into the atmosphere.

The incineration residue taken out of the gasifier can be solidified and treated with concrete, asphalt, etc., but this increases the volume and weight, and depending on the location where it is dumped, a secondary source of pollution There is also a possibility that Therefore, in the waste disposal method of the present invention, the incineration residue is once taken out of the gasification furnace and then stored in the melting furnace. Then, the incineration residue is heated and melted by a heating device of the melting furnace, and the melt is poured into water and rapidly cooled to form a granular solid. Even if there is waste that has not been sufficiently burned in the incineration residue, when it is heated in the melting furnace, the incineration residue, including the waste that has not been sufficiently burned, is completely burned, and metals and the like are burned. Only inorganic matter remains. Therefore, the inorganic substance is melted by further heating.

Since the incineration residue is at a high temperature although the temperature is lowered to such an extent that dioxins are not generated, the incineration residue can be easily melted by using the high temperature and heating it with a heating device of the melting furnace. . The melt that has been melted as described above is then pulverized by being put into water and rapidly cooled to obtain a granular solid. The granular solids have, for example, applications as aggregates for construction or civil engineering. Moreover, in this aspect, since the incineration residue is taken out after watering on the upper layer of the incineration residue in the gasification furnace, it is possible to prevent the incineration residue from scattering.

Further, in a second aspect of the present invention, in the waste incineration method, a portion of the waste in the gasification furnace where the waste can be carbonized is reduced with progress of carbonization of the waste in the gasification furnace. And removing the incineration residue from the gasification furnace when the temperature in the gasification furnace is decreasing from the maximum temperature after the temperature in the combustion furnace falls below the substantially constant temperature. Storing the incineration residue in the gasification furnace in a melting furnace connected to the incineration residue take-out port, and heating and melting the incineration residue by a heating device provided in the melting furnace; Charging and quenching to obtain granular solids; and removing the incineration residue from the gasifier, and then storing and igniting new waste in the gasifier. Features.

In the second aspect of the present invention, the portion of the waste gas in the gasifier that can be carbonized decreases with the progress of carbonization of the waste material in the gasification furnace, and the temperature in the combustion furnace becomes When it becomes impossible to maintain a substantially constant temperature equal to or higher than a predetermined temperature and the waste in the direct combustion state reaches a maximum temperature in the gasification furnace and then starts decreasing, the dioxins Removing the incineration residue from the gasifier regardless of the production temperature of the incinerator. In the case described above, there is a concern that dioxins may volatilize into the atmosphere from the incineration residue, but in this embodiment, the melting furnace is connected to the incineration residue discharge port of the gasification furnace. Therefore, the incineration residue can be taken out of the gasification furnace and stored in the melting furnace without volatilizing the dioxins.

Therefore, according to the second aspect of the present invention, after the portion where the carbonization of the waste in the gasification furnace can be reduced, the incineration residue is heated from the gasification furnace at a sufficiently high temperature. The incineration residue can be taken out, new waste can be put into the gasifier and ignited, and the processing cycle can be shortened. In addition, since new waste is introduced before the gasification furnace is cooled, the amount of heat required for the incineration can be reduced. The incineration residue contained in the melting furnace is heated and melted by a heating device provided in the melting furnace in the same manner as in the first embodiment, and the melt is poured into water. Rapid cooling to a granular solid.

Further, in each embodiment of the present invention, by melting the incineration residue with a flux, the melting point is lowered and melting becomes easier. Moreover, by adding the flux, the inorganic substance is included in the flux when the granular solid is generated, so that leakage of harmful substances such as heavy metals can be prevented.

As the flux, one of silicic acid, a silicic acid compound, a substance mainly containing a silicic acid compound, boric acid, a boric acid compound, a substance mainly containing a boric acid compound, an alkali metal compound, and an alkaline earth metal compound Alternatively, two or more kinds can be used in combination. Examples of the silicate compound or the substance containing the silicate compound as a main component include silica sand, mountain sand, river sand, silica stone, diatomaceous earth, sodium silicate, magnesium silicate, glass dust, clay, and the like.

The boric acid may be any of orthoboric acid, metaboric acid, tetraboric acid, and boron oxide. Further, the boric acid compound or the substance containing a boric acid compound as a main component includes orthoborates, metaborates, tetraborates, diborates, pentaborates, hexaborates, and octaborates. Salt, borax, calcium borate and the like can be mentioned. Examples of the alkali metal compound include soda ash, salt, caustic soda, and the like. Examples of the alkaline earth metal compound include quick lime, slaked lime, limestone, and the like.

Further, in each of the aspects of the present invention, when the incineration residue is melted, a waste gas obtained by burning in the combustion furnace a combustible gas generated by dry distillation of waste in the gasification furnace is used as the melting furnace. By heating the incineration residue, the heating by the heating device can be assisted and the cost for operating the heating device can be reduced. The heating device provided in the melting furnace may be a heating device or a combustion device such as a wrench, but when the heating device is a combustion device, the heating device is provided with heat of the melting furnace. By supplying oxygen heated by The operation cost of the device can be reduced.

Further, in each aspect of the present invention, heavy oil or the like can be used as the fuel of the combustion device. When the combustible gas is introduced into the combustion furnace and burned, a part of the combustible gas is used. The oil can be collected by collecting and condensing the oil, and the oil can be used as fuel for the combustion device. Thus, the operating cost of the heating device can be reduced by separating a part of the combustible gas, condensing and collecting the recovered oil as fuel for the combustion device. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a system configuration diagram showing one embodiment of the present invention, FIG. 2 is a system configuration diagram showing an embodiment of the present invention by enlarging the main part of FIG. 1, and FIG. It is a graph which shows the time change of the temperature in a gasifier and the combustion temperature in a combustion furnace in the incineration method of a thing. FIG. 4 is a system configuration diagram showing another embodiment of the present invention by enlarging the main parts of FIG. FIG. 5 is a graph showing changes over time in the temperature in the gasifier and the combustion temperature in the combustion furnace in the conventional incineration method. BEST MODE FOR CARRYING OUT THE INVENTION

Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

First, the configuration of the waste gasification and incineration equipment for waste used in the first embodiment of the present embodiment will be described with reference to FIGS. 1 and 2. FIG.

As shown in FIG. 1, the apparatus used in this embodiment includes a gasification furnace 1 containing waste A, which is a mixture of various wastes mainly composed of waste tires, and a gas passage 2 in the gasification furnace 1. And a ash treatment facility 4 for treating incineration residues such as incineration ash discharged from the gasification furnace 1 (hereinafter abbreviated as incineration).

An inlet 6 having an opening door 5 that can be opened and closed is formed on the upper surface of the gasifier 1, and waste A such as waste tires can be injected into the gasifier 1 from the inlet 6. So Then, when the charging door 5 is closed, the inside of the gasifier 1 is substantially shut off from the outside.

On the outer peripheral portion of the gasification furnace 1, a water jacket 1 separated from the inside of the gasification furnace 1 is formed as a cooling structure. The water jacket 7 is supplied with water by a water supply device (not shown), and the amount of water inside is maintained at a predetermined water level.

The lower part of the gasifier 1 is formed in the shape of a truncated cone protruding downward, opens below the ash treatment equipment 4 below the sloped side wall 8 and discharges the ash after the incineration of waste A is completed. An ash outlet 9 is formed. The ash outlet 9 is provided with a pair of bottom plates 10a, 10b which can be freely opened and closed and attached to a pair of left and right hinges 11a, 11b. The bottom plates 10a and 10b are swingable up and down by hinges lla and 11b, and the swing makes the ash outlet 9 openable and closable like a double door.

In the side wall part 8, an empty room 8a isolated from the inside of the gasification furnace 1 is formed, and the empty room 8a is formed through a plurality of air supply nozzles 12 provided in the inner wall part of the gasification furnace 1. And communicates with the inside of the gasifier 1. A gasification furnace oxygen supply path 13 is connected to the vacant chamber 8a, and the gasification furnace oxygen supply path 13 is connected to the oxygen supply passage 13 through a main oxygen supply path 14 by a blower fan or the like. (Air) Connected to source 15 A control valve 17 whose opening is controlled by a valve driver 16 is provided in the oxygen supply path 13 for the gasification furnace. In this case, the valve driver 16 is controlled by a control device 18 constituted by an electronic circuit including a CPU and the like.

Further, an ignition device 19 for igniting the waste A stored in the gasification furnace 1 under the control of the control device 18 is attached to a lower portion of the gasification furnace 1. The ignition device 19 is composed of an ignition burner and the like, and is supplied from the fuel supply device 20 in which auxiliary fuel such as heavy oil is stored via the main fuel supply passage 21 and the gasification furnace fuel supply passage 21a. The combustion flame is supplied to waste A by burning the supplied fuel.

Further, the gasification furnace 1 is provided with a watering conduit 22 penetrating the upper side wall. The watering conduit 22 is connected to a water source such as a water storage tank (not shown) through an on-off valve 23 whose opening and closing are controlled by a control device 18, and has a watering nozzle 24 at the tip thereof. Water supplied from the water source can be sprinkled into the gasification furnace 1.

The combustion furnace 3 includes a burner section 25 that mixes flammable gas generated by carbonization of waste A with oxygen (air) necessary for complete combustion thereof, and a combustion section 2 that burns flammable gas mixed with oxygen. The combustion section 26 communicates with the burner section 25 at the tip end of the parner section 25. A gas passage 2 is connected to the rear end of the burner section 25, and combustible gas generated by carbonization of the waste A in the gasification furnace 1 is introduced into the parner section 25 through the gas passage 2. Is done.

A void 27 is formed in the outer peripheral portion of the burner portion 25 and is isolated from the inside thereof. The void 27 is formed by a plurality of nozzles formed in the inner peripheral portion of the burner portion 25. It communicates with the inside of the parner part 25 through the hole 28. The vacant space 27 is connected to a combustion furnace oxygen supply passage 29 branched from the main oxygen supply passage 14. A control valve 31 whose opening is controlled by a valve driver 30 is provided in the combustion furnace oxygen supply passage 29, and the valve driver 30 is controlled by the control device 18.

Controlled by the controller 18, the rear end of the burner section 25 is supplied from the fuel supply apparatus 20 through the main fuel supply path 21 and the combustion furnace fuel supply path 21 b. A combustion device 32 for burning auxiliary fuel oil such as heavy oil is installed. The combustion device 32 is constituted by an ignition burner or the like, and burns the auxiliary combustion oil together with the combustible gas. The combustion device 32 is also used when igniting the combustible gas introduced into the parner section 25. A duct 33 a for discharging waste gas after the combustible gas is completely burned in the combustion unit 26 is provided at the tip of the combustion unit 26. Duct 3 3 a midway in a duct 3 3 a,, is branched into two 3 3 a _2, the duct 3 3 a, is connected to an end portion of the hand of the first heat exchanger 3 4, duct 3 3 a ₂ is connected to the ash treatment equipment 4, as will be described later. The first heat exchanger 34 has a main oxygen supply passage 14 disposed therein. By performing heat exchange between the waste gas and oxygen flowing through the main oxygen supply passage 14, a first heat exchanger 34 is provided. The oxygen is heated.

The other end of the first heat exchanger 34 is connected to a duct 33 b for discharging the waste gas that has exchanged heat with the oxygen. Duct 3 3 b, is connected to the first heat exchanger 3 4 Downstream, it merges with a duct 3 3 b ₂ that discharges waste gas from the ash processing equipment 4 described below to form a duct 33 b, and discharges the waste gas into the atmosphere from a chimney 36 through a blower fan 35 I do. A cyclone 37, a cooling tower 38, and a bag fill 39 are installed in the middle of the duct 33b.

Further, in the apparatus of the present embodiment, a separation pipe 40 for separating a part of the combustible gas introduced from the gasification furnace 1 into the combustion furnace 3 is provided via the check valve 41 in the middle of the gas passage 2. The flammable gas is guided to the oil recovery device 42. The oil recovery device 42 is composed of condensers 43a and 43b that condense the combustible gas that has been collected, and an oil separator that further recovers combustible components that are not condensed by the capacitors 43a and 43b. 4 4 The oil separator 4 4 is connected to the combustion furnace 3 by a gas conduit 4 5, and gas containing flammable components that cannot be separated even by the oil separator 4 4 passes through the gas conduit 4 5 via the blower fan 4 6. Then, it is introduced into the combustion part 26 of the combustion furnace 3 and is burned together with the combustible gas introduced into the combustion furnace 3 from the gas passage 2.

Below the condensers 43a and 43b, storage tanks 47a and 47b for storing condensed oil are provided. The oil condensed in the condensers 43a and 43b is led out of the storage tanks 47a and 47b by the recovered oil conduit 48, and the oil-water separator

49, After passing through the filter 50, it is sent to the fuel supply device 20 via the pump 51. The main fuel supply passage 21 for deriving fuel from the fuel supply device 20 is provided on the way with the gasification furnace fuel supply passage 21a and the combustion furnace fuel supply passage 21b as described later. It is branched into three, a fuel supply path for melting furnace 21 c connected to the ash processing equipment 4. Apparatus The present embodiment, the upper part of the gasification furnace 1 is attached a temperature sensor 5 2 for detecting the temperature T of the gasification furnace 1, the combustion furnace 3 to a temperature T ₂ in the combustion furnace 3 The temperature sensor 53 to be detected is attached at a position facing the tip of the parner 25. The detection signals of the temperature sensors 52 and 53 are input to the controller 18.

Next, as shown in Fig. 2, the ash processing equipment 4 includes a screw conveyor 54 provided below the ash outlet 9 for discharging the ash Β from the gasifier 1, and a screw conveyor

5 Flux adding device 5 5 provided above and along 4 4, and screw conveyor 5 A melting furnace 56 for containing and melting the mixture C of the incinerated material B and the flux carried by 4; a water tank 57 into which the melt D obtained in the melting furnace 56 is injected and quenched; and a water tank Five

And a belt conveyor 58 that carries out the cleaning power E from the belt 7. The melting furnace 56 receives the mixture C of the ash B and the flux, and heats and melts the mixture C. The melting furnace 59 communicates with the tip of the melting chamber 59, and is obtained in the melting chamber 59. A chute section 60 for introducing the melted material D into a water tank 57, and a flue 61 provided at a lower portion of the melting chamber 59 and communicating with the chute section 60 for discharging waste gas from the melting furnace 56. Consists of

On the upper surface of the melting chamber 59, there is formed an inlet 63 provided with an opening door 62 which can be opened and closed, and an inlet 6 for a mixture C of the ash B and the flux conveyed by the screw conveyor 54. From 3 it can be put into the melting chamber 59. The melting chamber 59 contains

The duct 3 3 a ₂ branching from the duct 3 3 a shown in FIG. 1 is connected so that a part of the waste gas from the combustion furnace 3 is introduced.

The ceiling part 60a of the chute part 60 is formed obliquely, and on the ceiling part 60a, the panners 64, 64 as heating devices are directed toward the mixture C in the melting chamber 59. Wearing. The burners 64 and 64 are connected from the fuel supply device 20 shown in FIG.

21. The mixture C in the melting chamber 59 is heated by burning the fuel supplied through the melting furnace fuel supply passage 21c.

Further, an oxygen supply path 65 for a melting furnace for supplying oxygen for combustion is connected to the parner 64. The oxygen supply line 65 for the melting furnace is connected to an air supply line 65a connected to an air supply source 66 constituted by a blower fan, etc., and to a pure oxygen source 67 constituted by an oxygen cylinder etc. And the pure oxygen supply path 65b is joined to supply air containing high-concentration oxygen in which pure oxygen is mixed with air to the parner 64.

The distal end side of the flue 61, the mixture C of the melting chamber 5 9 heating duct 3 3 b ₂ for discharging the waste gas is connected after the melt duct 3 3 b ₂ and the second heat It is connected to the duct 33b shown in Fig. 1 via the exchanger 68 and the cyclone 69. The said

Second heat exchanger 6-8, the internal air supply passage 6 5 a are disposed, between the air flowing in the waste gas and air supply passage 6 5 a supplied by a duct 3 3 b ₂ Heat exchange By performing the above, the air is heated.

Next, a first aspect of the waste incineration method of the present embodiment using the above-described apparatus will be described with reference to FIGS.

In the apparatus shown in FIG. 1, when incinerating waste A, first, the input door 5 is opened, and the waste A is injected into the gasification furnace 1 from the input port 6. The waste A is obtained by mixing various wastes, mainly waste tires, and when the combustible gas generated by dry distillation in the gasifier 1 continues to burn stably, the combustion temperature becomes 85. It is adjusted to have a calorific value of 0 ° C or more.

Next, after closing the charging door 5 to make the inside of the gasification furnace 1 a sealed state, prior to the ignition of the waste A, the control device 18 operates the combustion device 3 2 of the combustion furnace 3, Combustion of fuel oil is started. Temperature T ₂ of the combustion furnace 3 detected by the temperature sensor 5 3 exceeds the 8 0 0 ° C which is possible pyrolysis of dioxins, the ignition of the gasification furnace 1 by the control equipment 1 8 Device 19 is activated to ignite waste A, and partial combustion of waste A begins.

When the partial combustion of the waste A starts and the temperature detected by the temperature sensor ₅₂ reaches a predetermined temperature _{ 1 _} , the control device 18 stops the ignition device 19. When the partial combustion of the lower part of the waste 始まる starts, the upper part of the waste A is carbonized by the combustion heat, and the combustible gas generated by the carbonization is passed through the gas passage connected to the gasification furnace 1. Through 2, it is introduced into a parner section 25 of a combustion furnace 3.

The combustible gas introduced into the parner section 25 is mixed with oxygen supplied from the combustion furnace oxygen supply path 29 in the parner section 25 and ignited by the combustion flame supplied from the combustion device 32. Then, combustion is started in the combustion section 26 together with the auxiliary combustion oil. At the time when the combustion of the flammable gas is started, the generation of the flammable gas due to the dry distillation is unstable, and the flammable gas may not be stably supplied to the combustion furnace 3. As the dry distillation within 1 becomes stable, the combustible gas is continuously generated, and the amount of the generated combustible gas increases.

When the temperature T ₂ in the combustion furnace 3 increases with an increase in the amount of combustible gas generated, The combustible gas can continue burning stably spontaneously due to its own combustion heat. Therefore, when the temperature T ₂ in the combustion furnace 3 detected by the temperature sensor 53 becomes, for example, 830 ° C. or higher, the control device 18 stops the combustion of the auxiliary fuel oil by the combustion device 32. and, by a change in temperature T ₂ after the stop, it is determined whether the combustible gas can be continued stably burn spontaneously.

As a result, the combustion of the combustion assisting oil by the combustion device 32 is intermittent, such as stopping when the temperature 内₂ in the combustion furnace 3 becomes higher than 830 ° C, and restarting when the temperature Τ2 becomes lower than 830 ° C. During this time, the temperature T ₂ in the combustion furnace 3 changes zigzag as shown in FIG. Then, the even stop aids fuel combustion, if the temperature T ₂ in the combustion furnace 3 is adapted to maintain the 8 3 0 ° or C, the control unit 1 8, wherein the combustible gas is self It is determined that the state has reached a state in which the fuel can be spontaneously burned by the combustion heat of this, and the combustion of the auxiliary combustion oil is terminated. Thereafter, spontaneous combustion of only the flammable gas is performed, and the temperature T ₂ in the combustion furnace 3 detected by the temperature sensor 53 substantially indicates the combustion temperature of the flammable gas itself. become.

Wherein the spontaneous combustion of the combustible gas only is to be performed, the combustion temperature of the combustible gas itself detected by the temperature T ₂ in the combustion furnace 3, 8 3 0 ° C or higher, e.g. Maintained approximately constant at 850 ° C. At this time, the control device 18 controls the control valve 31 of the combustion furnace oxygen supply passage 29 so that a sufficient amount of oxygen necessary and sufficient for the combustible gas to completely burn is supplied to the panner section 25. Automatically controls the opening. At the same time, the control device 18 automatically controls the opening of the control valve 17 in accordance with the combustion temperature T ₂ of the combustible gas in the combustion furnace 3 detected by the temperature sensor 53, adjust the amount of generation of the combustible gas in the gasification furnace 1, the combustion temperature T ₂ of the combustible gas to be maintained substantially constant to 8 5 0 ° C in the combustion furnace 3.

In addition, the temperature T, in the gasification furnace 1 detected by the temperature sensor 52, during the operation of the combustion device 32, immediately after the waste A is ignited, the combustion of the lower part of the waste A It rises as it expands, but then falls once the heat of combustion in the lower part of waste A is consumed for carbonization of the upper part. And the combustion device 32 is stopped As a result, spontaneous combustion of only the flammable gas is performed, and the carbonization proceeds steadily and steadily (the temperature T ₂ in the combustion furnace 3 is maintained substantially constant at 850 ° C.). ), The temperature T, in the gasification furnace 1 starts to rise again and gradually rises as the dry distillation proceeds.

At the stage where only the flammable gas performs spontaneous combustion, the generation of the flammable gas is active, and even if a part of the flammable gas is fractionated, the temperature T ₂ in the combustion furnace 3 is increased by 8%. Sufficient flammable gas is obtained to keep it approximately constant at 50 ° C. Therefore, at this stage, a part of the flammable gas is fractionated by the fractionation conduit 40, and the flammable components contained in the flammable gas are recovered as oil by the oil recovery device 42.

When the pressure of the flammable gas in the gas passage 2 exceeds a predetermined value, the oil content is introduced into the oil recovery device 42 through the check valve 41 of the fractionation conduit 40. First, of the combustible gases, the combustible components that are easily liquefied are condensed by the condensers 43a and 43b arranged in series. The liquefied oil is stored in storage tanks 47a and 47b, and is then taken out by pump 51. The oil is purified by an oil / water separator 49 and a filter 50, and then sent to a fuel supply device 20, where the main fuel supply line 21 supplies a gasification furnace fuel supply passage 21a, a combustion furnace use. Through the fuel supply passage 21b and the melting furnace fuel supply passage 21c, respectively, the ignition device 19 of the gasification furnace 1, the combustion device 32 of the combustion furnace 3, and the burner 6 of the melting furnace 56 Supplied to 4.

The flammable gas not condensed by the condensers 43a and 43b is then sent to an oil separator 44, where the flammable components are recovered as oil. Then, the remaining combustible gas not recovered by the oil separator 44 is introduced into the combustion part 26 of the combustion furnace 3 via the gas fan 45 through the gas conduit 45 and is completely burned.

The waste gas after the combustible gas is completely burned in the combustion furnace 3 is first discharged to a duct 33a, and a part of the waste gas is sent to a first heat exchanger 34 by a duct 33a. It is used for heating oxygen flowing through the main oxygen supply passage 14 provided in the first heat exchanger 34. Another portion of the waste gas discharged into the duct 3 3 a is fed to the melting chamber 5 9 of the melting furnace 5 6 by duct Bok 3 3 a _2. Introduced to melting chamber 59 The function of the waste gas thus obtained will be described later.

The waste gas used for heating the oxygen in the first heat exchanger 34 is introduced into the cyclone 37 from the duct 33b through the duct 33b to remove dust contained in the waste gas. Is done. Next, the waste gas is sufficiently cooled by being introduced into the cooling tower 38, and is introduced into the bag filter 39. After finer fly ash is removed by the bag filter 39, the fly ash is finally discharged into the atmosphere from the chimney 36 through the blower fan 35.

Next, as the carbonization of the waste A in the gasification furnace 1 progresses and the portion where the carbonization of the waste A can be reduced, the control valve 17 of the gasification furnace oxygen supply path 13 a sufficient amount of flammable gas to be the adjusted opening also increases the oxygen supply amount to the gasification furnace 1 to maintain a substantially constant temperature T ₂ in the combustion furnace 3 to 8 5 0 ° C The temperature T ₂ in the combustion furnace 3 tends to decrease from 850 ° C. Therefore, when the temperature T ₂ in the combustion furnace 3 becomes, for example, 830 ° C. or less, the control device 18 restarts combustion of the auxiliary fuel oil by the combustion device 32. At this stage, the control device 1 8, a combustion furnace temperature T ₂ in the 3 stops auxiliary fuel for combustion by 8 3 0 ° combustor 3 2 If becomes more and C, the combustion furnace 3 after the stop the change in the temperature T _2, it is determined whether the combustible gas can be continued stably burn spontaneously. As a result, the combustion of the combustion assisting oil by the combustion device 32 is intermittent, such as stopping when the temperature 内₂ in the combustion furnace 3 becomes higher than 830 ° C, and restarting when the temperature Τ2 becomes lower than 830 ° C. During this time, the temperature T ₂ in the combustion furnace 3 changes zigzag as shown in FIG. Then, Without auxiliary fuel for combustion by a combustion device 3 2, if temperature T ₂ in the combustion furnace 3 is no longer rise to 8 3 0 ° or C, the control unit 1 8, wherein the combustible gas Judging that spontaneous combustion has become impossible at all, combustion of auxiliary fuel oil is continued as described above, and the temperature T ₂ in the combustion furnace 3 is maintained at 800 ° C. or higher. To be done.

On the other hand, if the portion of the waste A that can be carbonized becomes scarce, the waste A is directly burned in the gasifier 1, and the temperature T, in the gasifier 1, rises sharply. And Eliminates the carbonization and may portion of the waste material A, the waste material A that glowing of as a highest temperature transition was started Mel temperature T _x to ashing, starts to decrease. However, waste A varies in volume and material in each treatment, and therefore, there is a part that has become red-hot or has not yet become red-hot under the incinerated surface layer. The temperature in the gasifier 1 may increase again due to the heat of the portion.

Therefore, when the temperature T ₂ in the combustion furnace 3 does not rise to more than 8300 ° C unless the combustion oil is burned by the combustion device 32, the control device 18 detects the temperature using the temperature sensor 52. is the temperature T of the gasification furnace 1, every predetermined time, compared to the maximum temperature T _i of the gasification furnace 1, for example every 1 0 minutes. Then, when the temperature T, in the gasification furnace 1 is less than the maximum temperature _Τ1ΜΛΧ for a predetermined number of times, for example, three times in succession, the control device 18 ensures that the waste 内 in the gasification furnace 1 is totally It is determined that the incineration has shifted to the incineration. Thereafter, the temperature T, in the gasifier 1 gradually decreases with the incineration of the waste A. Here, the operation of discharging the incineration residue of waste A (ashed material B) from the gasifier 1 is conventionally performed at a temperature within the gasifier 1 at a temperature at which the incinerated material B is easily handled, for example, at room temperature. It is done waiting for it to fall to the extent. However, if waiting for the temperature T, to drop to about room temperature, it takes a long time for the temperature T, to decrease, and during this time, new waste cannot be put into the gasifier 1, so the treatment cycle is longer. Become. Therefore, in this embodiment, the portion where the waste A can be carbonized in the gasification furnace 1 becomes scarce, and the controller 18 ensures that the waste A in the gasification furnace 1 entirely shifts to incineration. Temperature, the temperature T, in the gasifier 1 _started to decrease from the maximum temperature of _{Τ1 となっ,} and fell _{below 250-350} ° C, which is the temperature at which dioxins are formed Immediately, for example, when the temperature T, becomes 200 ° C or less, open the bottom plates 10 a, 10 b of the ash outlet 9 of the gasifier 1 as shown by phantom lines in FIG. The ash B in the gasifier 1 is discharged by falling down.

In this embodiment, when the discharge (ashing) force of the incineration B in the gasification furnace 1 is completed, the bottom plates 10 a and 10 b are closed, the input door 5 is opened, and a new Re-inject waste A into gasifier 1. At this time, the temperature T ₂ in the combustion furnace 3 is Is maintained at 800 ° C. or higher as described above, so that the waste A re-charged into the gasifier 1 can be immediately ignited, and the following incineration treatment is performed according to the above-described procedure. Will be

By doing so, the ash B in the gasification furnace 1 is discharged without waiting for the temperature T, in the gasification furnace 1 to drop, and the new waste A is returned to the gasification furnace 1. Since it can be supplied, the processing cycle can be shortened. In addition, when new waste A is recharged, the gasification furnace 1 is heated by the residual heat of the previous treatment, so the partial combustion of waste A should be easily stabilized after the above-mentioned ignition. Can be.

Next, the treatment of the ash B discharged from the gasifier 1 will be described. At the time of discharge of the ash B, the temperature T, in the gasification furnace 1 has dropped to 200 ° C., which is lower than the dioxin formation temperature, as described above. There is no danger of occurrence. However, since the ash B is still at a high temperature, it is quickly introduced into the melting furnace 56 and melted.

In this embodiment, in order to quickly introduce the incinerated material B into the melting furnace 56, as shown in FIG. 2, the incinerated material is placed on a screw conveyor 54 provided below the ash outlet 9 of the gasification furnace 1. B is dropped and transported by the screw conveyor 54. Prior to opening the bottom plates 10a and 10b, the on-off valve 23 of the watering conduit 22 is opened by the control device 18 shown in FIG. Sprinkle water on the upper layer of ash B in gasification furnace 1 from 24. This makes it possible to prevent the ash B from scattering when the ash B falls onto the screw conveyor 54. Since the ash B is taken out of the gasifier 1 as described above, it is heated and melted in the melting furnace 56, so that the sprinkling is performed to such an extent that the upper layer of the ash B can be integrated with water. No need to overspray. The on-off valve 23 is closed again by the controller 18 after the valve is opened for the predetermined time.

Next, the charging door 62 of the melting furnace 56 is opened, and the ash B conveyed by the screw conveyor 54 is charged into the melting furnace 56 through the charging port 63. Above the screw conveyor 54, a flux adding device 55 is provided, and in this embodiment, silica is used as the flux. The mixture of sand and limestone is added to the ash B conveyed by the screw conveyor 54 from the fluxing device 55. Both the silica sand and the limestone are inexpensive, which is advantageous in suppressing the running cost. The ash B is mixed with the quartz sand and limestone while being conveyed by the screw conveyor 54, and the mixture C of the ash B and the quartz sand and limestone is put into the melting chamber 59 of the melting furnace 56. Is done.

The melter 5 9, the waste gas of the combustion furnace 3 by a duct 3 3 a ₂ branched from the duct 3 3 a has been introduced, the waste gas has a 8 5 0 ° C or higher temperature . Further, the burner 64 is operated before the mixture C is charged.

Then, the mixture C is heated by the waste gas and directly by the combustion flame of the panner 64. As described above, the mixture C contains the incinerated material B itself at a high temperature, and has a low melting point by being mixed with silica sand and limestone as the flux, so that the mixture is easily melted by the heating. Into a melt D. At the time of the melting, the incombustible waste A contained in the ash B is completely burned, but in the melting chamber 59, as described above, the temperature of the combustion furnace 3 is not lower than 850 ° C or more. Since waste gas with a temperature of is introduced, there is no risk of dioxins being generated by the combustion of waste A.

The melt D that has been melted as described above flows to the tip of the melting chamber 59, automatically falls into the chute 60, and is poured into a water tank 57 provided below the chute 60. Is done. The melt D charged into the water tank 57 is quenched by the water stored in the water tank 57 and crushed to form a fine granular solid (clean force E). The clinker E is discharged from the water tank 57 by a belt conveyor 58 disposed in the water tank 57. The silica sand is mixed with the ash B to lower the melting point of the mixture C and is melted to be vitreous, so that harmful substances such as heavy metals contained in the ash B are wrapped in the clinker E. However, leakage can be prevented. Waste gas of the melting furnace 5 6 melter 5 9 chute portion 6 0, through the flue 61, and is discharged by a duct 3 3 b _2. The waste gas is supplied to a second heat exchanger 68 provided in the middle of the duct 33 b ₂ by an air supply / supply passage 6 provided in the second heat exchanger 68. After exchanging heat with the air circulating in 5a and removing dust contained in cyclones 69, they join the duct 33b shown in Fig. 1 and enter the atmosphere from the chimney 36 together with the waste gas from the combustion furnace 3. Is discharged.

The burner 64 of the melting furnace 56 supplies the fuel supplied from the fuel supply device 20 through the main fuel supply path 21 and the melting fuel supply path 21 c to the oxygen supply for the melting furnace. The fuel is burned by the combustion air supplied from the road 65. The combustion air is supplied to the air heated by heat exchange with the waste gas supplied from the air supply path 65a from a pure oxygen supply source 67 through a pure oxygen supply path 65b. Pure oxygen is mixed. As a result, the combustion air has an increased oxygen concentration, and the panner 64 can obtain a high heating power suitable for melting the mixture C.

Next, a second aspect of the waste incineration method of the present embodiment will be described with reference to FIG.

The apparatus for dry distillation gasification and incineration of waste used in the second aspect of the present embodiment has exactly the same configuration as the apparatus used in the first aspect, except for the configuration of the ash treatment equipment 4. As shown in FIG. 4, the ash treatment equipment 4 of the present embodiment is formed by connecting the inlet 63 of the melting furnace 56 to the ash outlet 9 of the gasification furnace 1, and the bottom plates 10a, 10b Is opened in the input port 63, and the flux is directly injected into the input port 63 from the flux adding device 55, except for the first aspect. It has exactly the same configuration as the ash treatment equipment 4 shown in FIG.

Next, a second aspect of the waste incineration method of the present embodiment using the above-described apparatus will be described. In this embodiment, the waste is incinerated in exactly the same manner as in the first embodiment. Then, since the portion where the waste A could be carbonized in the gasification furnace 1 became scarce, the controller 18 determined that the waste A in the gasification furnace 1 completely shifted to incineration. after, when is declining from the temperature T, but the maximum temperature T _x of the gasification furnace 1, open the virtual line Shimesuru so the bottom plate 1 0 a, 1 0 b ash outlet 9 in FIG. 4 Kukoto As a result, the ash B in the gasifier 1 is dropped downward and discharged.

Then, in the present embodiment, the flux is directly injected into the inlet 63 from the flux adding device 55. Except for this point, the ash B is melted and clinker E is formed from the melt D by performing the same treatment as in the first embodiment. In the present embodiment, the ash B is discharged before the temperature T, in the gasification furnace 1 falls below the dioxin generation temperature, so that it is sufficiently high in temperature and can be easily melted.

In the ash processing equipment 4 used in the present embodiment, the inlets 63 of the melting furnace 56 shown in FIG. 4 are provided so as to be connected to the ash outlet 9 of the gasifier 1, so that the bottom plates 10a, 10b When opened, the incineration B is introduced into the melting chamber 59 of the melting furnace 56 without contacting the outside air. Therefore, in the present embodiment, without waiting for the temperature T in the gasification furnace 1 to fall below the dioxin formation temperature, for example, when the temperature reaches 300 ° C., the incineration B Discharge and re-input of new waste A can be performed, further shortening the processing cycle.

Claims

The scope of the claims

1. The process of igniting the waste stored in the gasification furnace to burn a part of the waste and carbonizing the other part of the waste by the combustion heat, and the flammability generated by the carbonization Introducing a gas into a combustion furnace and burning the gas,

When the combustible gas is burned in the combustion furnace, oxygen required for the combustion is supplied to the combustion furnace in accordance with the amount of the combustible gas introduced into the combustion furnace to burn the combustible gas. At the same time, the amount of oxygen supplied to the gasification furnace is controlled in accordance with a temperature change in the combustion furnace due to the combustion of the combustible gas in the combustion furnace, and the amount of combustible gas generated by the dry distillation is adjusted. A waste incineration method for maintaining the temperature in the combustion furnace at a substantially constant temperature equal to or higher than a predetermined temperature.

With the progress of the dry distillation of the waste in the gasification furnace, the portion of the waste in the gasification furnace that can be carbonized decreases, and after the temperature in the combustion furnace falls below the substantially constant temperature. Immediately removing the incineration residue from the gasification furnace when the temperature in the gasification furnace falls below the maximum temperature and becomes lower than the temperature at which dioxins are produced from the waste; Removing the incineration residue from the furnace, storing new waste in the gasifier, and igniting the waste.

2. The incineration residue taken out of the gasification furnace is stored in a melting furnace, heated and melted by a heating device provided in the melting furnace, and the molten material is poured into water and rapidly cooled to obtain a granular form. The incineration method of waste according to claim 1, wherein the waste is in a solid state.

3. The incineration method for waste according to claim 2, wherein a flux is added to the incineration residue to be melted.

4. When melting the incineration residue, combustible gas generated by dry distillation of the waste in the gasification furnace is introduced into the melting furnace, and waste gas generated by burning in the combustion furnace is introduced into the melting furnace; The waste incineration treatment method according to claim 2 or 3, wherein the incineration residue is heated.

5. The heating device provided in the melting furnace is a combustion device, and the heating device is provided with the melting device. The waste incineration method according to any one of claims 2 to 4, wherein oxygen heated by the heat of the melting furnace is supplied.

6. When the combustible gas generated by the dry distillation of the waste in the gasification furnace is introduced into the combustion furnace and burned, a part of the combustible gas is collected and condensed to collect the oil. 6. The waste incineration treatment method according to claim 5, wherein the oil is used as fuel for a combustion device provided in the melting furnace.

7. The waste according to any one of claims 1 to 6, wherein the incineration residue is taken out from the gasification furnace after water is sprayed on an upper layer of the incineration residue in the gasification furnace. Incineration method.

8. The process of igniting the waste stored in the gasification furnace to burn a part of the waste and carbonizing the other part of the waste by the combustion heat, and the flammability generated by the carbonization Introducing a gas into a combustion furnace and burning the gas,

When the combustible gas is burned in the combustion furnace, oxygen required for the combustion is supplied to the combustion furnace in accordance with the amount of the combustible gas introduced into the combustion furnace to burn the combustible gas. At the same time, the amount of oxygen supplied to the gasification furnace is controlled in accordance with a temperature change in the combustion furnace due to the combustion of the combustible gas in the combustion furnace, and the amount of combustible gas generated by the dry distillation is adjusted. A method for incinerating waste in which the temperature in the combustion furnace is maintained at a substantially constant temperature equal to or higher than a first predetermined temperature,

With the progress of the dry distillation of the waste in the gasification furnace, the portion of the waste in the gasification furnace that can be carbonized decreases, and after the temperature in the combustion furnace falls below the substantially constant temperature. When the temperature in the gasification furnace was decreasing from the maximum temperature, the incineration residue was taken out of the gasification furnace and connected to the gasification furnace through the incineration residue discharge port. Housed in a melting furnace;

Heating and melting the incineration residue by a heating device provided in the melting furnace, and charging the melt into water and quenching it to obtain a granular solid;

Removing the incineration residue from the gasifier, storing new waste in the gasifier and igniting the waste.

9. The waste incineration method according to claim 8, wherein a flux is added to the incineration residue to melt the residue.

10. When the incineration residue is melted, combustible gas generated by dry distillation of waste in the gasification furnace is burned in the combustion furnace, and waste gas generated is introduced into the melting furnace. 10. The waste incineration method according to claim 8, wherein the incineration residue is heated.

11. The heating device provided in the melting furnace is a combustion device, and supplies oxygen heated by the heat of the melting furnace to the combustion device. The waste incineration method according to any of the above items.

1 2. When the combustible gas generated by the dry distillation of the waste in the gasification furnace is introduced into the combustion furnace and burned, a part of the combustible gas is separated, condensed, and the oil is recovered. The waste incineration method according to claim 11, wherein the oil is collected and used as a fuel for a combustion device provided in the melting furnace.