JP3864833B2 - Burner type melting furnace - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a burner type melting furnace used for melting incineration ash discharged from a waste incinerator or the like such as municipal waste.
[0002]
[Prior art]
As the current waste disposal method, an incineration method is adopted in which waste is incinerated in an incinerator. However, since a large amount of ash is produced, the disposal is difficult, and it is necessary to secure a landfill. Due to problems such as approaching the limit, there is an increasing need to reduce the volume and volume of incinerated ash by melting. Therefore, burner type melting furnaces have recently been proposed in which unburned ash is left in the incinerated ash, and the incinerated ash containing the unburned ash is melted by combustion.
[0003]
This recently proposed burner-type melting furnace uses incineration ash from the incinerator as the main ash and melts the ash by mixing the main ash with the fly ash collected by the downstream bag filter. The molten slag is rapidly cooled and recovered as slag. As schematically shown in FIG. 2, a bottom hearth 2 is provided on one side of the lower end of the ash storage tank 1 extending in the vertical direction. The combustion chamber 4 having a large number of aeration nozzles 3 is continuously connected in a lateral direction so as to have a slightly downward gradient toward the downstream side, and the ash 5 in the ash storage tank 1 is placed on the other side of the lower end of the ash storage tank 1. A pusher 7 for pushing out to the hearth 2 of the combustion chamber 4 is provided, and unburned components in the ash 5 pushed onto the hearth 2 by the pusher 7 are heated by high-temperature air supplied through the aeration nozzle 3. By burning and melting the ash 5 with its heat, A surface melting part is formed in the vicinity of the 8 part of the mouth, and on the other hand, it is formed in a horizontally-oriented cylindrical shape and provided with a slag inlet 9 on one side of the bottom part and a slag outlet 10 on the other side of the bottom part side. And the bottom 8 between the slag inlet 9 and the slag outlet 10 is a hot water reservoir 11, and the outlet 8 of the combustion chamber 4 is tangentially connected to the slag inlet 9 of the melting furnace body 12. As a unitary structure, the molten slag 6 of the ash 5 flows from the surface melted portion near the outlet 8 portion of the combustion chamber 4 to the hot water sump 11, and the slag outlet 10 of the melting furnace body 12 is further connected. An auxiliary combustion burner 13 using kerosene or the like as a fuel is installed in a horizontal direction so that combustion gas 14 can be injected from the tangential direction, and injected into the melting furnace main body 12 from the tangential direction by the auxiliary combustion burner 13. Combustion gas 14 and the combustion chamber 4 The combustion gas 15 sent into the melting furnace body 12 is swirled, and the molten slag 6 that has flowed into the sump 11 in the melting furnace body 12 from the surface melting portion of the ash 5 in the combustion chamber 4 is Heating by the swirl flow (vortex flow) 16 of the combustion gases 14 and 15 promotes melting of the unmelted portion. The molten slag 6 overflows from the hot water reservoir 11 and is discharged through a slag outlet 10 to a slag cooling unit (not shown). The molten exhaust gas is an exhaust gas outlet provided on the end wall of the melting furnace body 12. 17 is discharged.
[0004]
Therefore, when the ash 5 is melted in the burner melting furnace, unburned components contained in the ash 5 are burned in the combustion chamber 4 by the high-temperature air supplied through the diffuser nozzle 3, and the combustion is performed. The ash 5 is melted by heat, the molten slag 6 in the surface melting portion is caused to flow into the hot water reservoir 11 of the melting furnace body 12, and the combustion gas 15 in the combustion chamber 4 flows into the melting furnace body 12. At this time, unburned ash is contained in the combustion gas 15 sent from the combustion chamber 4 into the melting furnace main body 12, and unmelted ash and iron pieces that are not completely melted in the molten slag 6. It is included. In the melting furnace main body 12, a swirl flow 16 is formed by the combustion gas 14 from the auxiliary burner 13 and the combustion gas 15 from the combustion chamber 4, and the unburned ash in the combustion gas 15 is caused by the swirl flow 16. Since it is burned and melted, the amount of ash entrained in the exhaust gas is reduced, and unmelted ash, iron pieces, etc. in the molten slag 6 flowing into the hot water sump 11 are swirled 16. Convection heat transfer due to the heat, radiant heat transfer from the furnace walls and combustion gases 14 and 15, and conduction heat transfer from the sump 11 are added, so that it can be completely melted by a high melting load. The slag discharged from the tap 10 and solidified in the cooling section is effectively reused as an asphalt mixed material, a sidewalk block or the like.
[0005]
[Problems to be solved by the invention]
However, in the burner type melting furnace, since the ash mixed with the main ash and fly ash is melted, the finally obtained slag contains iron and chlorine. Although it can be removed by applying it to a magnetic separator, chlorine cannot be removed easily, making it difficult to reuse slag. That is, since the exhaust gas generated in the incinerator has a regulated hydrogen chloride concentration when released from the chimney to the atmosphere, normally, slaked lime is supplied upstream of the bag filter and 2HCl + Ca (OH) ₂ = CaCl. By carrying out the reaction of ₂ + 2H ₂ O, the hydrogen chloride concentration is kept within a specified value. However, chlorine is taken into the fly ash collected by the bag filter. From the viewpoint of decomposition of dioxins, it is desirable that this fly ash is mixed with the main ash and melted, but from the viewpoint of slag reuse, it causes chlorine precipitation and weakening of the slag itself. There is a problem.
[0006]
Therefore, the present invention is intended to facilitate the reuse of the collected slag.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention connects an outlet of a combustion chamber for melting ash supplied from an ash storage tank by combustion on one side of the bottom of a horizontal cylindrical melting furnace body having a bottom as a hot water reservoir. In the burner-type melting furnace, in which a combustion burner is installed in the melting furnace body and the molten slag flowing into the hot water reservoir of the melting furnace body is heated from the combustion chamber, the ash storage tank The ash treatment area that reaches the melting furnace main body is divided into a main ash treatment area and a fly ash treatment area by a partition, and the main ash and fly ash are burned separately to form slag as the main ash at the bottom of the melting furnace main body. The main ash slag outlet is provided on the other side of the bottom of the melting furnace main body so as to correspond to the main ash hot water reservoir and the fly ash hot water reservoir. And a fly ash slag tap.
[0008]
Since main ash and fly ash are processed separately, main ash slag containing no chlorine and fly ash slag containing chlorine can be collected separately. Therefore, it becomes easy to reuse slag.
[0009]
Also, the auxiliary ash burner is installed in the main ash treatment area, and the height of the partition located in the melting furnace body is higher than the upper end of the slag outlet. As a result, the combustion heat in the main ash treatment area can be circulated into the fly ash treatment area, so that a heat source for fly ash can be dispensed with.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
FIG. 1 shows an embodiment of the present invention, and as shown in FIG. 2, an ash storage tank is provided on one side of the bottom side of a melting furnace main body 12 formed in a horizontal cylindrical shape with a bottom as a hot water reservoir 11. An outlet 8 of the combustion chamber 4 provided in a sideways manner at the lower end of 1 is connected in a tangential direction, an auxiliary burner 13 is installed at the upper part of the melting furnace main body 12, and combustion gas 14 and combustion from the auxiliary burner 13 are combusted. In a burner type melting furnace in which the molten slag in the hot water reservoir 11 is heated by the swirl flow 16 with the combustion gas 15 from the chamber 4, the hot water of the melting furnace main body 12 passes from the ash storage tank 1 through the combustion chamber 4. In the ash treatment area that reaches the reservoir 11, an intermediate partition 18 that is divided into left and right for the main ash and fly ash is continuously arranged, and a treatment area on one side partitioned by the partition 18 is referred to as a main ash treatment area 19a. In addition, the processing area on the opposite side is treated as the fly ash processing area 19. In the main ash treatment area 19a, only the main ash 5a is treated, and in the fly ash treatment area 19b, only the fly ash 5b is treated to separate the main ash molten slag 6a and the fly ash molten slag 6b. The hot ash reservoirs 11a and 11b are further stored, and the main ash hot water reservoir 11a of the main ash treatment area 19a and the fly ash of the fly ash treatment area 19b are provided on the other side of the bottom of the melting furnace body 12. A main ash slag outlet 10a and a fly ash slag outlet 10b are provided corresponding to each of the hot water reservoirs 11b, and the main ash molten slag 6a and the fly ash molten slag 6b are separately discharged, and the main ash is discharged. The slag 6A and the fly ash slag 6B are collected separately.
[0012]
More specifically, the inner partition 18 is extended from the melting furnace main body 12 through the combustion chamber 4 into the ash storage tank 1, and in the ash storage tank 1, main ash that stores only the main ash 5 a by the partition 18. The storage tank section 1a and the fly ash storage tank section 1b for storing only the fly ash 5b are partitioned, and in the combustion chamber 4, the main ash 5a pushed out by the pusher 7 and the fly ash 5b corresponding to the angle of repose. Fly ash which forms the partition 18 so that an edge inclines toward the inside of the melting furnace main body 12, and melts only the main ash combustion chamber part 4a and the fly ash 5b by melting only the main ash 5a by combustion The combustion chamber portion 4b is partitioned and the height of the partition 18 is set in the melting furnace main body 12 so that the upper ash slag outlet 10a and the fly ash slag outlet 10b are in communication with the upper space. The main ash should be adjusted to the height level. A fly ash water reservoir 11b for storing only bottom ash water reservoir 11a and the fly ash molten slag 6b for storing only fusion slag 6a are to be defined and formed. The pusher 7 is provided with a slit 20 on the distal end side so as not to interfere with the partition 18. Further, the auxiliary burner 13 is installed so as to be located in the main ash treatment area 19a. Other configurations are the same as those shown in FIG.
[0013]
The main ash 5a is stored in the main ash storage tank 1a of the main ash treatment area 19a, and the fly ash 5b is separately input and stored in the fly ash storage tank 1b of the fly ash processing area 19b. The main ash 5a in the main ash storage tank section 1a and the fly ash 5b in the fly ash storage tank section 1b are supplied to the main ash combustion chamber section 4a and the fly ash combustion chamber section 4b of the combustion chamber 4 simultaneously and separately. The main ash 5a and the fly ash 5b pushed out to the combustion chamber portions 4a and 4b are burned separately by the high-temperature air supplied through the aeration nozzle 3 and are melted by the combustion heat. The ash 5a can be separated into the main ash molten slag 6a, and the fly ash 5b can be separated into the main ash hot water reservoir 11a and the fly ash hot water reservoir 11b of the melting furnace body 12 separately as the fly ash molten slag 6b. Here, it is further heated by the swirling flow 16 by the combustion gas 14 from the auxiliary burner 13 and the combustion gas 15 from the combustion chambers 4a, 4b, and melting is promoted separately. The main ash molten slag 6a and the fly ash molten slag 6b are separately overflowed from the main ash hot water reservoir 11a and the fly ash hot water reservoir 11b with the partition 18 interposed therebetween, and the main ash molten slag 6a is the main ash molten slag 6a. The fly ash molten slag 6b is cooled after being discharged from the tap shed 10a and from the fly ash slag tap outlet 10b, and recovered separately as main ash slag 6A and fly ash slag 6B.
[0014]
Thus, since the main ash 5a containing no chlorine and the fly ash 5b containing chlorine can be processed simultaneously and separately in one melting furnace, without reducing the processing amount of the entire ash, The main ash slag 6A that can be reused and the fly ash slag 6B that is difficult to reuse can be collected separately. Therefore, the slag can be easily reused, and the quality of the reused product can be stably maintained for a long time.
[0015]
In the above, the auxiliary burner 13 is installed at a position corresponding to the main ash treatment region 19a, but the melting temperature of the fly ash 5b is lower than the melting temperature of the main ash 5a and from the upper part in the combustion chamber 4. Since the inner partition 18 is not positioned over the upper part in the melting furnace main body 12, the swirl flow 16 gets over the inner partition 18 and goes around to the fly ash treatment region 19b, so that the fly ash 5b is melted by the combustion heat. Therefore, a heat source for fly ash can be dispensed with.
[0016]
【The invention's effect】
As described above, according to the burner type melting furnace of the present invention, the following excellent effects are exhibited.
(1) The melting furnace is connected to and communicated with an outlet of a combustion chamber that melts the ash supplied from the ash storage tank by combustion on one side of the bottom of a horizontal cylindrical melting furnace main body having a bottom as a hot water reservoir. In the burner-type melting furnace in which an auxiliary combustion burner is installed in the main body and the molten slag flowing from the combustion chamber into the sump of the melting furnace main body is heated, the ash treatment area from the ash storage tank to the melting furnace main body Is divided into a main ash treatment area and a fly ash treatment area by a partition, and the main ash and fly ash are burned separately to form a main ash hot water reservoir and a fly ash hot water reservoir at the bottom of the melting furnace main body as slag. In addition, a main ash slag outlet and a fly ash slag outlet are provided on the other side of the bottom of the melting furnace main body in correspondence with the main ash hot water reservoir and the fly ash hot water reservoir. The main ash and fly ash can be melted separately. Can, thereby, since the fly ash slag that contains the bottom ash slag and chlorine does not contain chlorine can be recovered separately, it is possible to easily reuse the slag.
(2) A configuration in which the position of the auxiliary burner is set as the main ash treatment area, and the height of the partition located in the melting furnace main body is higher than the upper end of the slag outlet. By doing so, the combustion heat in the main ash treatment area can be circulated into the fly ash treatment area, and the fly ash can be melted by that heat, eliminating the need for a dedicated heat source for fly ash. Can be advantageous.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a burner type melting furnace of the present invention.
FIG. 2 is a schematic view of a recently proposed burner type melting furnace.
[Explanation of symbols]
1 Ash storage tank 4 Combustion chamber 5 Ash 5a Main ash 5b Fly ash 8 Exit 10a Main ash slag outlet 10b Fly ash slag outlet 11 Hot water reservoir 11a Main ash hot water reservoir 11b Fly ash hot water reservoir 12 Melting furnace main body 13 Auxiliary burner 18 Partition 19a Main ash treatment area 19b Fly ash treatment area

Claims (2)

  An outlet of a combustion chamber that melts the ash supplied from the ash storage tank by combustion is connected to one side of the bottom of the horizontal cylindrical melting furnace main body with a bottom serving as a hot water reservoir, and auxiliary combustion is provided to the melting furnace main body. In the burner type melting furnace in which a burner is installed to heat the molten slag flowing from the combustion chamber into the hot water reservoir of the melting furnace body, the ash treatment area from the ash storage tank to the melting furnace body is The main ash and fly ash are separated into partitions by the partition, and the main ash and fly ash are separately burned and stored as slag in the main ash hot water reservoir and the fly ash hot water reservoir at the bottom of the melting furnace body. In addition, on the other side of the bottom of the melting furnace main body, a structure in which a main ash slag tap and a fly ash slag tap are provided in correspondence with the main ash hot water reservoir and the fly ash hot water reservoir. A burner-type melting furnace comprising: The height of the partition of the part located in the melting furnace main body is set as the position higher than the upper end of the slag outlet, where the installation position of the auxiliary burner is the main ash treatment region. Burner type melting furnace.

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