JP3611277B2 - Slag crystallization conveyor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a slag crystallization conveyor for crystallization of slag by installing it in a melting furnace that melts various wastes or incineration ash thereof, coal ash generated from a commercial thermal power plant, and the like into slag.
[0002]
[Prior art]
FIG. 5 shows a conventional burner type ash melting furnace 31 for melting incinerated ash and a slag crystallization conveyor 32 disposed downstream thereof. The ash melting furnace 31 heats the pulverized incinerated ash to form slag, and then throws the slag into the crystallization conveyor 32 via the slag removal chamber 33 below.
[0003]
FIG. 6 is a sectional view of the downstream side of the crystallization conveyor 32. As shown in the drawing, a conveyor main body 34 is provided inside the crystallization conveyor 32, and a pan 36 for receiving the slag 35 is attached to the conveyor main body 34. The conveyor body 34 is connected to a pair of endless chains 38 that drive the conveyor body 34, and is disposed along the outer wall 37 of the crystallization conveyor 32. A gap 39 is formed on the outer wall of the crystallization conveyor 32 to connect the conveyor main body 34 and the endless chain 38 inside and outside the crystallization conveyor 32. A water cooling jacket 40 for cooling the endless chain 38 is disposed on the side of the endless chain 38.
[0004]
With such a configuration, the slag 35 discharged from the slag removal chamber 33 is initially at a high temperature of about 1400 ° C. In order to crystallize the slag 35, it is necessary to maintain a high temperature range of 800 ° C. or higher, but the slag 35 is rapidly cooled to 800 ° C. or less as time passes. Therefore, the crystallization conveyor 32 is provided with a heating burner 41 for maintaining the temperature at which the slag 35 is crystallized.
[0005]
[Problems to be solved by the invention]
When the heating burner 41 was burned to maintain the slag in the high temperature region, the high temperature exhaust gas a in the crystallization conveyor 32 leaked from the gap 39 and sprayed directly onto the endless chain 38. Therefore, the endless chain 38 is heated and the endless chain 38 may be damaged. In order to prevent this, the endless chain 38 uses heat-resistant steel and is provided with a water cooling jacket 40.
However, if the water cooling jacket 40 is used to cool the endless chain 38, the water cooling structure is provided separately, so that the crystallization conveyor structure becomes complicated. If the material of the endless chain 38 is made of heat resistant steel, the cost increases. It has become.
This invention is made | formed in view of the said subject, and it aims at providing the slag crystallization conveyor of an ash melting furnace with a simple structure and low cost.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a plurality of pans for receiving slag melted in an ash melting furnace, and is connected to an endless chain to drive the pan. In the slag crystallization conveyor in which the endless chain is provided on the outside of the casing, suction means for forcibly sucking out the exhaust gas inside the casing is provided in the casing, and the inside of the casing is made negative pressure so that the pan and the endless Air was introduced from the gap formed in the connecting part of the chain, and the endless chain was cooled by air.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a slag crystallization conveyor according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a burner type ash melting furnace 1, a slag crystallization conveyor 2 disposed on the downstream side thereof, and its associated equipment. The ash melting furnace 1 was provided with an incineration ash burner 4 for injecting incineration ash into the furnace chamber 3 and a fuel burner 5 for injecting heavy oil. In the lower part of the ash melting furnace 1, a slag removal chamber 7 for discharging slag flowing down from the ash melting furnace 1 is disposed.
[0008]
The crystallization conveyor 2 described above is installed in the lower part of the slag removal chamber 7. 2 and 3 are cross-sectional views of the downstream end side inside the crystallization conveyor 2 covered with the casing 10 having a heat-resistant structure. The crystallization conveyor 2 having a ring-shaped cross section is provided with a conveyor main body 12, and a plurality of pans 8 that house the slag 11 and move in the crystallization conveyor 2 are connected to the conveyor main body 12. Yes. In the crystallization conveyor 2, an endless chain 9 for transmitting the conveyor main body 12 is adjacent along the axial direction of the crystallization conveyor 2. The endless chain 9 is made of non-heat resistant material. A gap 14 is formed on the side of the crystallization conveyor 2 along the connecting portion so that the conveyor main body 12 and the endless chain 9 inside and outside the crystallization conveyor 2 can be connected. A pair of weirs 14 a that make it difficult for the exhaust gas to flow out of the gap 14 are formed on the inner wall of the casing 10 at the site where the gap 14 is provided. Combustion burners 15 a and 15 b for heating the slag 11 are provided on the upper portion of the casing 10 of the crystallization conveyor 2.
[0009]
As shown in FIGS. 1 and 2, the crystallization conveyor 2 has a suction port 16 for exhausting the gas inside the upper portion of the casing 10, that is, the upper space 10 a of the conveyor body 12 that divides the inside of the casing 10 up and down. Is provided. The suction port 16 is provided with a damper 18 and an exhaust fan 19 via a duct 17. A temperature detector 20 is provided in the vicinity of the inlet of the exhaust fan 19, and a damper opening / closing adjuster 21 that adjusts the opening degree of the damper 18 based on the measurement result of the detector 20 is provided.
Further, a suction port 13 for cooling air is provided in the lower portion of the casing 10, that is, in the lower space 10 b of the conveyor body 12, and the suction port 13 communicates with the duct 17.
As shown in FIG. 1, a secondary combustion chamber 6 is disposed in the upper part of the ash melting furnace 1, and a water tank 22 for granulating the crystallized slag 11 is installed at the downstream end of the crystallization conveyor 2. did. An exhaust gas treatment system gas cooling tower 23, a fan 24, and a smoke washing tower 25 are connected to the secondary combustion chamber 6 disposed in the upper part of the ash melting furnace 1 through a duct.
[0010]
As mentioned above, although the structure of the slag crystallization conveyor by embodiment of this invention was demonstrated, the effect | action is demonstrated next.
When the incinerated ash powder is injected from the burner 4 into the furnace chamber 3, the auxiliary fuel injected from the fuel burner 5 burns. The incinerated ash melts and slags by being heated at a high temperature of about 1300 to 1600 ° C. in the furnace chamber 3 and flows down to the slag removal chamber 7 below the ash melting furnace 1. On the other hand, the gas combusted in the furnace chamber 3 rises and is introduced into the secondary combustion chamber 6 and is discharged after being processed in the downstream process.
[0011]
The slag flowing down into the slag removal chamber 7 is put into the crystallization conveyor 2, accommodated in a pan 8 disposed therein, and slowly moves on the conveyor body 12. As described above, the slag 11 in a state of approximately 1400 ° C. is rapidly cooled when left standing, but is adjusted to be in the temperature range shown in FIG. 4 in order to crystallize. That is, the slag 11 is maintained for about 1 hour in the 700 ° C. zone B, and is then maintained for about 1 hour in the downstream 900 ° C. zone A for crystallization. This temperature maintenance is performed by burning the combustion burners 15a and 15b.
[0012]
Although the inside of the casing 10 of the crystallization conveyor 2 is maintained at a high temperature as described above, the exhaust fan 19 is driven so that the exhaust gas from the combustion burner 15 is sucked and exhausted from the casing 10 through the duct 17. . At this time, the upper space 10a in the casing 10 has a negative pressure, and as shown in FIG. 2, the air b enters the inside through the gap 14 from the outside. Therefore, the endless chain 9 is cooled by air instead of being sprayed with exhaust gas unlike the conventional case. The air b flows into the lower space 10b because the suction port 13 communicates with the duct 17.
In the present embodiment, the temperature detector 20 and the damper opening / closing adjuster 21 are used, and the cold air in the lower space 10b is introduced into the duct 17 so that the inlet of the exhaust fan 19 is always 300 ° C. or less. The temperatures of the 900 ° C. zone A and 700 ° C. zone B in the conversion conveyor 2 (however, the setting of each temperature slightly changes depending on the slag properties) are maintained. The weir 14a provided in the casing 10 makes it difficult to mix the hot air in the upper space 10a and the cold air in the lower space 10b, so that the temperatures of the zones A and B can be effectively maintained at a predetermined temperature. Can do. The exhaust gas exhausted from the exhaust fan 19 passes through the duct 17 and is joined to the exhaust gas system of the downstream duct of the smoke tower 25.
The crystallized slag in the crystallization conveyor 2 is discharged from the tip of the crystallization conveyor 2 to the water tank 22 and subjected to water granulation.
[0013]
As described above, according to the present embodiment, the exhaust gas in the casing 10 is not sprayed on the endless chain 9 that moves the conveyor body 12, and the endless chain 9 is cooled by air. Never become. Therefore, a non-heat-resistant material can be used for the endless chain 9 and the conventionally used water cooling structure can be eliminated, so that the crystallization conveyor 2 can be simplified and the cost can be reduced.
Since the exhaust gas generated in the crystallization conveyor 2 is introduced into the exhaust gas treatment system, the untreated exhaust gas does not leak outside. Further, since the exhaust gas is 300 ° C. or less, it can be directly introduced into the smoke-washing tower 25 without passing through the gas-cooling tower 23, and there is no burden on the gas-cooling tower 23 and the fan 24. The exhaust fan 19 can be used with a normal fan material.
[0014]
The embodiment of the present invention has been described above. Of course, the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.
For example, according to the above embodiment, the suction port 16 for exhausting exhaust gas is provided in the 900 ° C. zone A, but the suction port is not limited to the 900 ° C. zone A but may be provided in the 700 ° C. zone B.
[0015]
【The invention's effect】
According to the present invention, the exhaust gas in the casing is not sprayed onto the endless chain that moves the conveyor main body, and the endless chain is cooled by air, so that it does not reach a high temperature. Therefore, a non-heat-resistant material can be used as the material of the endless chain, and the conventionally used water-cooling structure can be eliminated, so that the crystallization conveyor can be simplified and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic view of a slag crystallization conveyor and a burner type ash melting furnace according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view of a slag crystallization conveyor according to an embodiment of the present invention.
FIG. 3 is a side view showing an endless chain and a pan of the slag crystallization conveyor according to the embodiment of the present invention.
FIG. 4 is a diagram showing conditions for crystallization of slag by the slag crystallization conveyor according to the embodiment of the present invention.
FIG. 5 is a schematic view of a conventional slag crystallization conveyor and a burner ash melting furnace.
FIG. 6 is a schematic cross-sectional view of a slag crystallization conveyor according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Burner type ash melting furnace 2 Crystallization conveyor 3 Furnace chamber 4 Incineration ash burner 5 Combustion burner 6 Secondary combustion chamber 7 Slag removal chamber 8 Pan 9 Endless chain 10 Casing 11 Slag 12 Conveyor body 13, 16 Suction port 14 Clearance 14a Weir 15a, 15b Combustion burner 17 Duct 18 Damper 19 Exhaust fan 20 Temperature detector 21 Damper opening / closing regulator 22 Water tank 23 Gas cooling tower 24 Fan 25 Smoke tower

Claims (3)

A pan for receiving the slag melted in the melting furnace is arranged and driven by being connected to an endless chain, the pan movement path is covered with a heat-resistant casing, and the endless chain is provided outside the casing. In the slag crystallization conveyor, the endless chain is provided with exhaust means for sucking out the exhaust gas inside the casing, and the inside of the casing is made negative pressure so that air is sucked from a gap formed in the connecting portion between the pan and the endless chain. A slag crystallization conveyor characterized by being air-cooled. 2. The slag crystallization conveyor according to claim 1, further comprising an adjusting means for adjusting an exhaust gas suction amount so that an inlet side exhaust gas temperature of the exhaust means becomes a predetermined temperature. The slag crystallization conveyor according to claim 1 or 2, wherein the exhaust gas exhausted from the exhaust means is constituted by an exhaust gas fan that guides the exhaust gas to a treatment device for exhaust gas discharged from the melting furnace.

Images