JP2003042429A - Ash melting furnace equipment for gasifying/melting plasma, and method for its control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the area of a site required for ash melting equipment by reducing the total energy required for ash melting without performing ash melting before starting power generation. SOLUTION: There are provided a refuse incinerator 1 where remaining heat recovery equipment 16 and power generating equipment 19 are provided, and a plasma ash melting furnace 2 for melting ash 12, 25 discharged from the incinerator 1. A bypass 27 is provided at an outlet 16a of the remaining heat recovery equipment 16 and is opened and closed with a partition plate 26, an end of which bypass 27 is connected with an ash melting burner 28 provided on the plasma ash melting furnace 2. When the power generation equipment 19 does not generate electricity, the incinerator 1 is operated in a low air ratio, and a waste gas line 20 is defined with the partition plate 26. High calorie gas 38 obtained from the incinerator 1 is supplied as a fuel to the burner 26 through the bypass 27 from the outlet 16a of the remaining heat recovery equipment 16, while increased uncombusted carbon in main ash 12 obtained from the incinerator 1 is supplied as an ash melting heating source of the plasma ash melting furnace 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasification and melting plasma for melting incineration ash of sewage sludge, municipal waste, industrial waste and the like and incinerator ash discharged from incinerators of commercial thermal power plants by high temperature plasma The present invention relates to an ash melting furnace facility and a starting method thereof.

[0002]

2. Description of the Related Art Conventionally, sewage sludge, municipal solid waste, industrial waste, etc. are incinerated by a refuse incinerator, etc. It is melted in a melting furnace and taken out as molten slag and molten metal for various uses. In order to melt the incineration ash in the furnace main body using such a plasma ash melting furnace, for example, the incineration ash discharged from the refuse incinerator is put into the furnace main body through various transportation means and supply means. , The incinerated ash charged is melted by the high temperature plasma generated between the furnace bottom electrode and the main electrode. The molten slag and molten metal generated in the furnace body are discharged from the outlet through the outlet gutter and guided to the slag pit and the metal pit via a conveyor (not shown).

[0003]

By the way, in the above plasma ash melting furnace, electricity is required to generate a plasma arc between the electrodes. For this reason, the plasma ash melting furnace cannot be started for about a day or more after starting the operation of the refuse incinerator, generating steam in the boiler, and moving the generator by the steam turbine to start power generation. Therefore, in order to prevent ash from overflowing from the main ash pit and the fly ash pit, it was necessary to prepare an ash pit capable of storing ash for three days or more for safety reasons. With the increase in such ash pits, the conventional ash melting facility requires a large site area, which causes a problem that the facility cost increases. In addition, if it is desired to perform the ash melting process before the start of power generation, it is necessary to purchase electricity from an electric power company or the like, which may result in a high cost of the ash melting process.

The present invention has been made in view of such circumstances, and an object thereof is to reduce the total energy required for ash melting and to perform ash melting before the start of power generation without purchasing electricity. An object of the present invention is to provide a gasification and melting plasma ash melting furnace equipment capable of reducing the site area required for the ash melting equipment and a starting method thereof.

[0005]

In order to solve the above-mentioned problems of the prior art, in the present invention, a waste incinerator provided with a residual heat recovery facility and a power generation facility, and the waste incinerator are discharged. A plasma ash melting furnace for melting ash, a bypass opened and closed by a partition plate is provided at an outlet of the residual heat recovery equipment, and an end of the bypass is provided in the plasma ash melting furnace. Connect to
While not generating power in the power generation equipment, the waste incinerator is operated at a low air ratio, the exhaust gas line of the waste incinerator is partitioned by the partition plate, and high calorie gas obtained from the waste incinerator is used as the residual heat. While supplying as fuel to the burner from the outlet of the recovery facility via the bypass,
The increased unburned carbon in the ash obtained from the refuse incinerator is supplied as a heating source for ash melting in the plasma ash melting furnace. Further, in the present invention, it is preferable that the burner is arranged at a right angle to an angle of repose of ash supplied into the plasma ash melting furnace. Further, in the present invention, it is preferable that the upper end portion of the furnace bottom electrode of the plasma ash melting furnace is disposed above the slag line in the furnace body when the power generation facility is not generating power. Further, in the present invention, it is preferable that the main electrode of the plasma ash melting furnace is arranged at a position where it conducts (contacts) with the metal in the furnace body.

Further, the present invention provides a gasified molten plasma ash equipped with a refuse incinerator provided with a residual heat recovery facility and a power generation facility, and a plasma ash melting furnace for melting ash discharged from the refuse incinerator. A method of starting a melting furnace facility, when the power generation facility is not generating power, by operating the refuse incinerator at a low air ratio, to obtain high calorie gas and increase unburned carbon in ash, While supplying the high-calorie gas from the outlet of the residual heat recovery equipment to the ash melting burner provided in the plasma ash melting furnace as a fuel, the increased unburned carbon is ash melted in the plasma ash melting furnace. It is supplied as a heating source for the plasma ash and the plasma ash melting furnace is started.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A gasification melting plasma ash melting furnace facility and a method of starting the same according to the present invention will be described below in detail with reference to the illustrated embodiments. Here, FIG. 1 is a schematic diagram of a refuse incinerator applied to the gasification melting plasma ash melting furnace equipment of the embodiment of the present invention, and FIG. 2 is applied to the gasification melting plasma ash melting furnace equipment of the embodiment of the present invention. FIG. 3 is a schematic view of a plasma ash melting furnace to be used.

The gasification melting plasma ash melting furnace equipment according to the present embodiment comprises a waste incinerator 1 for incinerating the waste supplied by a waste supply crane from a waste pit (not shown),
A plasma ash melting furnace 2 for melting the ash discharged from the refuse incinerator 1 is provided. As shown in FIG. 1, the refuse incinerator 1 has a combustion stoker 7 that incinerates the refuse 6 that is put into the furnace 5 from the hopper 3 through the feeder 4, and a blower 8 that sends combustion air into the furnace 5. Between the blower 8 and the furnace 5, the first pipe 10 for feeding the main combustion air to the combustion stoker 7 via the adjusting valve 9a and the adjusting valve 9 are provided.
A second pipe 11 for supplying secondary combustion air to above the combustion stoker 7 via b is provided. Moreover, the waste incinerator 1 is provided with a clinker roller 14 for dropping the main ash 12 incinerated by the combustion stoker 7 to the ash extruding device 13, and the cooled main ash 12 is drawn by the ash extruding device 13. It is pushed out to the outer main ash pit and is carried into the plasma ash melting furnace 2 from the main ash pit.

Further, the refuse incinerator 1 is provided with a residual heat recovery equipment 16 having a boiler 15 and a power generation equipment 19 connected to the residual heat recovery equipment 16 and having a steam turbine 17 and a generator 18. Outlet part 1 of residual heat recovery equipment 16
In 6a, a temperature reducing tower 21, a bag filter 22, a chimney 23, and the like, which form a normal exhaust gas line 20 of the refuse incinerator 1, are installed side by side. The exhaust gas 24 generated in the furnace 5 of the refuse incinerator 1 is removed of dust and halogen substances contained therein while passing through the exhaust gas line 20 from the exit portion 16a of the residual heat recovery facility 16, and is discharged from the chimney 23 into the atmosphere. It is supposed to be released. The fly ash 25 collected by the bag filter 22 is sent to a fly ash pit (not shown) and carried into the plasma ash melting furnace 2 through the fly ash pit.

Further, an outlet 16a of the residual heat recovery equipment 16 is provided with one end of a bypass 27 which is opened and closed by a partition plate (partition valve) 26, and the other end of the bypass 27 is connected to the plasma ash melting furnace 2 It is connected to the base end portion of the ash melting burner 28 provided in the above (see FIG. 2). Partition plate 26
Divides the exhaust gas line 20 to shut off the flow of the exhaust gas 24 from the outlet portion 16a of the residual heat recovery equipment 16 to the exhaust gas line 20, and in this state, the bypass 27 opens and the waste incinerator 1 of the waste incinerator 1 is opened. The furnace 5 and the ash melting burner 28 communicate with each other via the outlet 16 a of the residual heat recovery equipment 16 and the bypass 27.

On the other hand, as shown in FIG. 2, the plasma ash melting furnace 2 is a box-shaped furnace body 2 having a refractory structure.
9, a furnace main body 29 is provided on its lower side surface with a slag port 33 for discharging the molten slag 30, the molten metal 31, and the exhaust gas 32, and a downwardly inclined slag gutter 34 connected to the slag port 33. There is. The molten slag 30 is discharged by an overflow method that overflows from the furnace body 29 through the outlet 33. A main electrode (plasma torch) 35 and a furnace bottom electrode 36, which are connected to a DC power supply device (not shown), are arranged facing each other at the center of the upper and lower portions of the furnace body 29.
Nitrogen gas is supplied to the main electrode 35 from a nitrogen gas generator (not shown), and the main ash 12 and fly ash 25 that are input are generated between the main electrode 35 and the bottom electrode 36. It is designed to be melted by heating with a plasma arc. Therefore, an ash charging port 37 for charging the main ash 12 and the fly ash 25 into the furnace body 29 is provided on the side surface of the furnace body 29 opposite to the outlet 33.

The ash melting burner 28 is used in the power generation equipment 19
When the power is not being generated by or when the amount of power generation is insufficient, the main ash 12 and the fly ash 25 are combusted and melted by ignition, which will be described later sent from the refuse incinerator 1. The high calorie gas 38 is used as fuel. When the calorific value of the high-calorie gas 38 is insufficient, liquid or gaseous fuel is supplemented as necessary. In addition, the ash melting burner 28 is provided at the outlet 3
3, which is provided on the side surface of the furnace body 29 located above 3, and is inclined so as to be perpendicular to the repose angle (the maximum angle at which the slope does not collapse) of the main ash 12 and the fly ash 25 supplied into the furnace body 29. The main ash 12 and the fly ash 25 are easily melted.

In the ash melting burner 28, the furnace body 29
Since the main ash 12 and the fly ash 25 supplied inside are burning, and only the surface side will be melted, it is necessary to make a metal contact for conduction when the plasma arc is started,
The upper end of the furnace bottom electrode 36 of the plasma ash melting furnace 2 is located above the slag line L in the furnace body 29, and the main electrode 3
It is arranged so as to abut the lower end portion of 5. For this reason, on the upper surface of the furnace bottom electrode 36, a rod of a conductor 39 (carbon or metal) constituting the furnace bottom electrode 36 is erected upright. here,
The slag line L means a boundary line between the molten slag 30 in the furnace body 29 and the gas atmosphere. In addition, on the downstream side of the plasma ash melting furnace 2, the secondary combustion chamber 40, the temperature reducing tower 41, and the bag filter 4 arranged along the flow of the exhaust gas 32.
2. An exhaust gas treatment facility including an induction blower 43, a smoke washing tower 44, and a chimney 45 is provided.

In the gasification melting plasma ash melting furnace facility of this embodiment, when the power generation amount is insufficient or when power generation is impossible, the refuse incinerator 1 is operated at a low air ratio and the normal exhaust gas line 20 is used. Is separated by a partition plate 26, and all of the high-calorie gas 38 obtained from the inside 5 of the refuse incinerator 1 is circulated from the outlet 16a of the residual heat recovery equipment 16 into the bypass 27, and is used as fuel for the ash melting burner 28. The main ash 1 in the furnace body 29 of the plasma ash melting furnace 2 that is supplied and further increases the unburned carbon in the main ash 12 obtained from the furnace 5 of the refuse incinerator 1.
2 and fly ash 25 are supplied as a fuel (heat source for melting ash) for heating. This high calorie gas 3
Reference numeral 8 is an exhaust gas containing a large amount of combustible components such as hydrocarbons, hydrogen and carbon monoxide. The operation of the refuse incinerator 1 at a low air ratio reduces the feed amount of the main combustion air from the blower 8 to the combustion stoker 7 by squeezing the adjusting valve 9a of the first pipe 10, and the adjusting valve of the second pipe 11. This is performed by closing 9b and stopping the supply of the secondary combustion air from the blower 8 to above the combustion stoker 7.

Next, the operation and starting method of the gasification and melting plasma ash melting furnace equipment of this embodiment will be described. When the power generation facility 19 is not generating power, as shown by the arrow in FIG.
Electricity is not supplied from the generator 18 to the power source of the plasma ash melting furnace 2, and the plasma ash melting furnace 2 cannot be started. Therefore, by adjusting the adjusting valves 9a and 9b,
The feed amount of the main combustion air is reduced, and the feed of the secondary combustion air is stopped, the refuse incinerator 1 is operated at a low air ratio, and the normal exhaust gas line 20 is partitioned by the partition plate 26, Outlet portion 16a of residual heat recovery equipment 16 and exhaust gas line 2
0 is cut off. When such an operation is performed, the high-calorie gas 38 containing a large amount of combustible components in the furnace 5 of the refuse incinerator 1
And the unburned carbon in the incinerated main ash 12 increases. The obtained high-calorie gas 38 rises in the furnace 5 and flows to the outlet 16a of the residual heat recovery equipment 16, is guided to the ash melting burner 28 through the bypass 27, and the burner 2
8 fuel. In addition, the main ash 12 with an increased unburned carbon is taken out from the refuse incinerator 1 and other ash 1
2, 25 are charged into the furnace body 29 of the plasma ash melting furnace 2 and supplied as a heating source for ash melting.

Therefore, when the burner 28 is ignited, the plasma ash melting furnace 2 is started, the flame of the burner 28 burns and melts the main ash 12 and the fly ash 25 in the furnace body 29, and the molten slag 30 And so on, it will be discharged from the outlet 33 through the outlet gutter 34. That is, when the predetermined amount of main ash 12 and fly ash 25 stored in each ash pit is carried into the furnace body 29 of the plasma ash melting furnace 2, the ash is melted. At this time, the burner 28 is the main ash 12
Further, since the ash arranged in a right angle to the angle of repose of the fly ash 25 and the ash containing a large amount of increased unburned carbon is burned, the melting process can be smoothly performed. When the amount of power generated by the power generation facility 19 becomes sufficient or when the power generation by the generator 18 becomes possible, the regulating valves 9a and 9b are returned to their original positions so that a predetermined amount of main combustion air and secondary combustion air can be obtained. And the waste incinerator 1 is operated normally, and the partition of the exhaust gas line 20 by the partition plate 26 is released.
The outlet part 16a of the residual heat recovery equipment 16 and the exhaust gas line 20 are connected. Then, a DC power supply (not shown) is turned on, the main ash 12 and the fly ash 25 are charged from the ash charging port 37, and the voltage is applied between the main electrode 35 and the furnace bottom electrode 36 in a state where the furnace body 29 is in a reducing atmosphere. Apply to. Then, a plasma arc is generated between the main electrode 35 and the conductor 39 and the furnace bottom electrode 36, and the inside of the furnace body 29 becomes an atmosphere of 1000 ° C. or higher, and the main ash 12 and the fly ash 25 are heated and melted. To do. When the molten slag 30 and the molten metal 31 are accumulated in the furnace bottom in a predetermined amount, the molten slag 30 is discharged from the outlet 3 as described above.
It will overflow from No. 3 and will pass through the debris gutter 34 and will be discharged.

In the gasification and melting plasma ash melting furnace equipment and the starting method thereof according to the embodiment of the present invention, the refuse incinerator 1 is operated at a low air ratio, and the exhaust gas line 20 is partitioned by the partition plate 26 so that the plasma ash melting furnace is operated. 2 ash melting burner 28
After opening the bypass 27, take out the high-calorie gas 38 and the main ash 12 containing a large amount of unburned carbon from the refuse incinerator 1,
Since the high-calorie gas 38 is supplied as fuel to the burner 28 from the outlet 16a of the residual heat recovery equipment 16 via the bypass 27, the increased unburned carbon is supplied as a heating source for ash melting of the plasma ash melting furnace 2. Even when the power generation amount of the power generation equipment 19 is insufficient or power generation is impossible, ash melting is possible, and it is not necessary to purchase electricity to start the plasma ash melting furnace 2. Moreover, since the high ash calorie gas 38 and the main ash 12 containing a large amount of unburned carbon are used for the fuel and the heating source, the energy required for melting the ash can be reduced. In addition, consumption of the main ash 12 and the fly ash 25 can reduce the amount of ash stored in the main ash pit and the fly ash pit. Therefore, the size of these ash pits can be reduced to about 1/3 of the conventional size. It can be reduced.

The embodiment of the present invention has been described above.
The present invention is not limited to the above-described embodiments, and various changes and modifications can be made based on the technical idea of the present invention. For example, in the above-described embodiment, the metal 3 of the plasma arc activation causes the bottom electrode 36 to move to the conductor 3
Although 9 is installed upright, the main electrode 35 may be extended downward and arranged at a position in contact with the metal in the furnace body 29.

[0019]

As described above, the gasification melting plasma ash melting furnace equipment according to the present invention melts the ash discharged from the waste incinerator provided with the residual heat recovery equipment and the power generation equipment. A plasma ash melting furnace to be provided, a bypass opened and closed by a partition plate is provided at the outlet of the residual heat recovery equipment, and the end of the bypass is connected to an ash melting burner provided in the plasma ash melting furnace. When the power generation facility is not generating power, the waste incinerator is operated at a low air ratio, the exhaust gas line of the waste incinerator is partitioned by the partition plate, and the high-calorie gas obtained from the waste incinerator is described above. While supplying fuel to the burner from the outlet of the residual heat recovery facility through the bypass, the increased unburned carbon in the ash obtained from the refuse incinerator is used as a heating source for ash melting in the plasma ash melting furnace. Since it is supplied, the total energy required for ash melting can be reduced by using high calorie gas and increased unburned carbon, and ash melting can be performed without purchasing electricity from a power company before power generation starts. The cost of the treatment can be reduced, and the site area required for the ash melting facility can be reduced by reducing the ash pit, and the facility cost can be reduced.

The method for starting the gasification melting plasma ash melting furnace equipment according to the present invention melts the waste incinerator provided with the residual heat recovery equipment and the power generation equipment and the ash discharged from the waste incinerator. A method of starting equipment equipped with a plasma ash melting furnace, when the power generation equipment is not generating power, by operating the refuse incinerator at a low air ratio, to obtain a high calorie gas and unburned in the ash Carbon is increased and the high-calorie gas is supplied as fuel from an outlet of the residual heat recovery equipment to an ash melting burner provided in the plasma ash melting furnace, while the increased unburned carbon is added to the plasma ash. The plasma ash melting furnace is supplied as a heating source for ash melting of the melting furnace, and the plasma ash melting furnace is started. It can be carried out in.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a refuse incinerator applied to a gasification melting plasma ash melting furnace facility of an embodiment of the present invention.

FIG. 2 is a schematic view showing a plasma ash melting furnace applied to the gasification melting plasma ash melting furnace facility of the embodiment of the present invention.

[Explanation of symbols]

1 garbage incinerator 2 Plasma ash melting furnace 3 hoppers 4 feeder 5 inside the furnace 6 garbage 7 burning stoker 8 blower 9a, 9b Regulator valve 10, 11 piping 12 main ash 13 Ash extrusion equipment 14 Clinkerola 15 boiler 16 Residual heat recovery equipment 16a outlet 17 Steam turbine 18 generator 19 power generation equipment 20 exhaust gas line 24 exhaust gas 25 fly ash 26 partition boards 27 Bypass 28 Burner for melting ash 29 furnace body 30 Molten slag 33 Debris mouth 34 Degreed gutter 35 Main electrode 36 Furnace bottom electrode 37 Ash input port 38 high calorie gas 39 Conductor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C02F 11/06 C02F 11/10 Z 4G075 11/10 F23G 5/00 115Z 4K045 C10L 3/06 5/14 F 4K063 F23G 5/00 115 5/46 ZABA 5/14 F27B 3/08 5/46 ZAB 3/20 F27B 3/08 3/22 3/20 F27D 11/10 3/22 13/00 E F27D 11/10 B09B 3/00 303L 13/00 303J 303M C10L 3/00 A (72) Inventor Keita Inoue 12 Nishiki-cho, Naka-ku, Yokohama-shi, Kanagawa Mitsubishi Heavy Industries, Ltd. Yokohama Factory F-term (reference) 3K061 AA01 AB03 AC01 BA01 BA07 CA14 DA19 DB01 DB11 NB02 NB03 3K065 AA01 AB01 AB03 AC01 BA01 JA05 JA18 3K078 AA01 BA03 BA21 CA02 CA09 CA21 CA24 4D004 AA02 AA36 AA46 BA03 CA22 CA26 CA27 CA28 CA43 CB 31 CB34 4D059 AA03 BB01 BB03 BB11 CA10 CC03 4G075 AA37 BB03 CA02 CA47 DA01 EB41 EC21 4K045 AA04 BA07 RB02 RB08 RB12 RB22 4K063 AA04 BA13 CA04 CA06 FA56 GA02 GA03 GA31

Claims (5)

[Claims] 1. A waste incinerator provided with a residual heat recovery facility and a power generation facility, and a plasma ash melting furnace for melting ash discharged from the waste incinerator, and a partition at the exit of the residual heat recovery facility. A bypass that is opened and closed by a plate is provided, an end portion of the bypass is connected to an ash melting burner provided in the plasma ash melting furnace, and when the power generation facility is not generating power, the waste incinerator is set to low air. While operating at a ratio, the exhaust gas line of the refuse incinerator is partitioned by the partition plate, and the high-calorie gas obtained from the refuse incinerator is supplied as fuel to the burner from the outlet of the residual heat recovery facility through the bypass. On the other hand, a gasification melting plasma ash melting furnace facility, wherein increased unburned carbon in ash obtained from the refuse incinerator is supplied as a heating source for ash melting of the plasma ash melting furnace. 2. The gasification melting plasma ash melting furnace facility according to claim 1, wherein the burner is arranged at a right angle to an angle of repose of ash supplied into the plasma ash melting furnace. . 3. The gasification melting plasma ash melting according to claim 1, wherein an upper end portion of the furnace bottom electrode of the plasma ash melting furnace is arranged above a slag line in the furnace body. Furnace equipment. 4. The gasification melting plasma ash melting furnace facility according to claim 1, wherein the main electrode of the plasma ash melting furnace is arranged at a position in contact with the metal in the furnace body. 5. A gasification melting plasma ash melting furnace facility comprising a refuse incinerator provided with a residual heat recovery facility and a power generation facility, and a plasma ash melting furnace for melting ash discharged from the waste incinerator. A start-up method, when the power generation facility is not generating power, by operating the refuse incinerator at a low air ratio, to obtain high calorie gas and increase unburned carbon in ash, the high calorie gas While supplying as a fuel from the outlet of the residual heat recovery equipment to the ash melting burner provided in the plasma ash melting furnace, the increased unburned carbon as a ash melting heating source of the plasma ash melting furnace A method for starting gasification and melting plasma ash melting furnace equipment, which comprises supplying and activating the plasma ash melting furnace.