JP4307087B2 - Method and apparatus for effective use of slag - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is, for example, a waste incinerator that incinerates garbage such as general waste and industrial waste, or an ash melting furnace, or a waste treatment facility that treats waste into molten slag like a gasification melting furnace. The present invention relates to a method for effectively using slag applied to the apparatus and improvement of the apparatus.
[0002]
[Prior art]
In general, there are two types of waste treatment facilities that process waste into molten slag: a waste incinerator with an ash melting furnace and a gasification melting furnace, and especially a waste incinerator with an ash melting furnace. For example, what is shown in FIG. 3 is known (see Patent Documents 1 to 7).
[0003]
The waste treatment facility 50 includes an incinerator 51 that incinerates waste, a waste heat boiler 52 that recovers heat of exhaust gas discharged from the incinerator 51, and a bug filter 53 that collects fly ash contained in the future exhaust gas. An induction fan 54 that attracts the exhaust gas from now on, a chimney 55 that releases the exhaust gas from now on to the atmosphere, a melting furnace 56 that melts the incineration ash from the incinerator 51 and the fly ash from the back filter 53, Combustion chamber 57 for burning the exhaust gas in the future, a temperature reducing tower 58 for reducing the temperature of the exhaust gas in the future, a bag filter 59 for collecting the molten fly ash contained in the exhaust gas in the future, and attracting the exhaust gas in the future And an induction fan 60 that discharges from the chimney 55.
The bag filters 53 and 59 constitute a dry exhaust gas treatment facility for the incinerator 51 and the melting furnace 56, and an alkali agent (neutralizing agent) A such as slaked lime and a reaction aid B are put together on the inlet side. Supplied. Alkaline agent A is introduced to neutralize the exhaust gas to the bag filters 53 and 59. The reaction aid B is added to suppress an increase in pressure loss on the filters of the bag filters 53 and 59 and to increase the efficiency of removing acidic gas.
[0004]
Thus, the waste treatment facility 50 includes a crusher 61 that crushes the molten slag C from the melting furnace 56, and a sieving machine 62 that separates the slag from this into fine slag D and other coarse slag E. I have. The sieve 62 has a sieve mesh of 0.075 mm.
The coarse slag E on the sieve larger than the sieve screen sorted by the sieving machine 62 is effectively used for roadbed materials and the like, and the fine slag D below the sieve mesh smaller than the sieve mesh is landfilled.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 56-115401 [Patent Document 2]
Japanese Patent Laid-Open No. 7-204604 [Patent Document 3]
Japanese Patent No. 3146919 [Patent Document 4]
Japanese Patent Laid-Open No. 10-77602 [Patent Document 5]
Japanese Patent Laid-Open No. 10-227431 [Patent Document 6]
JP 2000-205536 A [Patent Document 7]
JP-A-2001-276774 [0006]
[Problems to be solved by the invention]
In short, the molten slag generated from the melting furnace is crushed by a crusher in order to effectively use it for roadbed materials, etc., but the fine slag generated at that time was removed because it could be scattered. There was no use to use.
[0007]
The present invention was devised in view of the problems described above, and the problem to be solved is a method for effectively utilizing slag and a method for solving the intended use of fine-grained slag. To provide the equipment.
[0008]
[Means for Solving the Problems]
The effective use method of the slag of the present invention is basically to separate the fine slag having scattering properties after crushing the molten slag from the melting furnace provided in the incinerator, and each of the incinerator and the melting furnace . supplies to the inlet side of each of the Bac filter is exhaust gas treatment system of an alkali agent for neutralizing the acid gases in the exhaust gas, it said as a reaction aid for the alkali agent to an inlet side of each of said bag filter A feature resides in the supply of fine slag by pneumatic means . Further, the effective utilization method of the slag according to the present invention includes, as another means, separating the fine slag having scattering properties after crushing the molten slag from the gasification melting furnace, and using the exhaust gas treatment facility of the gasification melting furnace. An alkaline agent for neutralizing acidic gas in the exhaust gas is supplied to the inlet side of a vacuum filter, and the fine slag is supplied to the inlet side of the vacuum filter as a reaction aid for the alkaline agent by air transport means. There is a feature in doing.
[0009]
The apparatus for effectively using slag according to the present invention includes a crusher for crushing molten slag from a melting furnace attached to an incinerator, and a sieve for separating fine slag having scattering properties from the molten slag crushed by the crusher. A bag filter that is an exhaust gas treatment facility of each of the incinerator and the melting furnace , and means for supplying an alkaline agent for neutralizing acid gas in the exhaust gas to the inlet side of each of the back filters, And air transport means for blowing the fine slag into the inlet side of each bag filter as a reaction aid for the alkaline agent . In addition, the slag effective utilization apparatus of the present invention includes, as another means, a crusher that crushes molten slag from a gasification melting furnace, and a fine slag that is scattered from the molten slag crushed by the crusher. A sieving machine for separating; a back filter as an exhaust gas treatment facility for the gasification melting furnace; means for supplying an alkaline agent to the inlet side of the bag filter for neutralizing acidic gas in the exhaust gas; and the alkaline agent And a pneumatic transportation means for blowing the fine slag into the bag filter inlet side as a reaction aid.
[0010]
The molten slag from the melting furnace is crushed by a crusher and then separated into fine slag and coarse slag by a sieving machine. Coarse-grained slag is effectively used for roadbed materials and the like as in the past. The fine-grained slag is blown together with an alkali agent as a reaction aid into the inlet side of the back filter, which is an exhaust gas treatment facility for incinerators and melting furnaces, depending on the air transportation means. Accordingly, fine slag that has been disposed of in the past can be effectively used as a reaction aid. As a result, the cost of the reaction aid can be reduced.
[0011]
It is preferred to further grind the fine slag. In this way, it is possible to improve the wiping-off property on the filter cloth of the bag filter and the reactivity of the alkaline agent.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing a waste treatment facility suitable for adopting the method for effectively using slag according to the first example of the present invention.
[0013]
The waste treatment facility 1 includes an incinerator 2 that incinerates waste, a waste heat boiler 3 that recovers heat of exhaust gas discharged from the waste, a bug filter 4 that collects fly ash contained in the exhaust gas from now on, An induction fan 5 for attracting future exhaust gas, a chimney 6 for releasing the future exhaust gas to the atmosphere, a melting furnace 7 for melting incineration ash from the incinerator 2 and fly ash from the back filter 4, and A combustion chamber 8 for burning the exhaust gas, a temperature reducing tower 9 for reducing the temperature of the future exhaust gas, a bag filter 10 for collecting molten fly ash contained in the future exhaust gas, and attracting the future exhaust gas And an induction fan 11 for discharging from the chimney 6.
[0014]
Thus, the waste treatment facility 1 includes a crusher 12 for crushing the molten slag C from the melting furnace 7, a sieving machine 13 for separating the slag from this into fine slag D and other coarse slag E, Air transport means 14 for blowing the fine slag D in the future together with the alkaline agent A to each inlet side of the back filter 4, 10, which is a dry exhaust gas treatment facility of the incinerator 2 and the melting furnace 7, depends on these This is a so-called effective use device for slag.
[0015]
In the sieving machine 13, a sieve having a sieve mesh of 0.075 mm is used. Fine slag D smaller than this is separated under the sieving, and coarse slag E larger than this is separated on the sieving. ing.
[0016]
Although not shown, the pneumatic transport means 14 is a silo for storing the fine slag D from the sieving machine 13, a quantitative feeder for sending the fine slag D stored here in a fixed quantity, and a fine granule from this A duct that guides the slag D to the inlet side (inlet duct) of the bag filters 4 and 10 of the incinerator 2 and the melting furnace 7, and a blower that blows air through the fine slag D to the inlet side of the bag filters 4 and 10. Etc.
[0017]
Next, the operation will be described based on such a configuration.
Garbage is thrown into the incinerator 2 and incinerated. The exhaust gas from the incinerator 2 is recovered by the waste heat boiler 3 and then fly ash (dust, solid compounds, and heavy metals) contained therein is collected by the bag filter 4. The exhaust gas from the bag filter 4 is attracted by the induction fan 5 and released from the chimney 6 to the atmosphere.
The incineration ash discharged from the incinerator 2 and the fly ash from the back filter 4 are sent to the melting furnace 7 where they are melted. The exhaust gas from the melting furnace 7 is combusted in the combustion chamber 8 and reduced in temperature in the temperature reducing tower 9, and the molten fly ash contained therein is collected by the bag filter 10. The exhaust gas from the bag filter 10 is attracted by the induction fan 11 and discharged from the chimney 6 to the atmosphere.
[0018]
The molten slag C discharged from the melting furnace 7 is crushed by the crusher 12 and then separated by the sieving machine 13 into fine slag D on the sieve and coarse slag E under the sieve. Coarse grain slag E is effectively used for roadbed materials and the like as in the past. The fine slag D is blown together with the alkali agent A as a reaction aid B on the inlet side of the back filter 4, 10 which is an exhaust gas treatment facility of the incinerator 2 and the melting furnace 7 by the air transport means 14.
[0019]
By the way, when using alkali agent A such as slaked lime in a dry exhaust gas treatment facility, the reaction aid B is used to suppress an increase in pressure loss on the filter and increase the efficiency of removing acidic gas. There are many things to do.
As the reaction aid B, those containing silicon (Si) and aluminum (Al) as main components are used. On the other hand, fine slag D obtained by crushing and screening molten slag C is mainly composed of silicon (Si), aluminum (Al), calcium (Ca), and is glassy. It can be used because it is similar in physical properties to a commonly used reaction aid such as lack of hygroscopicity.
Therefore, the fine slag D which has been disposed of in the past can be effectively used as the reaction aid B. As a result, the cost of the reaction aid can be reduced.
[0020]
Next, a second example of the present invention will be described with reference to FIG.
FIG. 2 is a schematic diagram showing a waste treatment facility suitable for adopting the slag effective utilization method according to the second example of the present invention.
[0021]
The second example is different from the first example in that a pulverizer 15 for further finely pulverizing the fine slag D is provided between the sieving machine 13 and the air transporting means 14. is there.
The crusher 15 grinds the fine slag D from the sieving machine 13 to an average of about 20 to 30 μm.
In such a case, since the fine grain slag D is further finer, it is possible to improve the wiping-off property on the filter cloth of the bag filters 4 and 10 and the reactivity of the alkaline agent A.
[0022]
In the previous example, the sieve 13 has a sieve mesh of 0.075 mm. However, the sieve 13 is not limited to this and may have other sizes, for example.
In the previous example, the pneumatic transport means 14 is provided with a silo, a quantitative feeder, a duct, a blower, and the like.
[0023]
【The invention's effect】
As described above, according to the present invention, the following excellent effects can be obtained.
(1) Since the fine slag produced after crushing the molten slag is used as a reaction aid in the back filter, which is an exhaust gas treatment facility for the incinerator and melting furnace, the fine slag can be effectively used.
(2) Since the fine slag is used as a reaction aid, the cost of the reaction aid can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a waste treatment facility suitable for adopting a method for effectively using slag according to a first example of the present invention.
FIG. 2 is a schematic diagram showing a waste treatment facility suitable for adopting a method for effectively using slag according to a second example of the present invention.
FIG. 3 is a schematic diagram showing a conventional waste treatment facility.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,50 ... Waste disposal equipment, 2,51 ... Incinerator, 3,52 ... Waste heat boiler, 4, 10, 53, 59 ... Bag filter, 5, 11, 54, 60 ... Induction fan, 6,55 ... Chimney, 7, 56 ... Melting furnace, 8, 57 ... Combustion chamber, 9, 58 ... Temperature reduction tower, 12, 61 ... Crusher, 13, 62 ... Sieve machine, 14 ... Air transport means, 15 ... Crusher, A ... Alkaline agent, B ... Reaction aid, C ... Molten slag, D ... Fine slag, E ... Coarse slag.

Claims (8)

Fractionating fine slag with fluffy after crushing melting furnace or these molten slag provided together in the incinerator,
While supplying an alkaline agent for neutralizing the acid gas in the exhaust gas to the inlet side of each back filter that is an exhaust gas treatment facility of each of the incinerator and melting furnace ,
An effective utilization method of slag, characterized in that the fine slag is supplied to the inlet side of each bag filter as a reaction aid for the alkaline agent by air transportation means . After smashing the molten slag from the gasification melting furnace, it separates the fine slag with scattering properties,
While supplying an alkali agent for neutralizing acid gas in the exhaust gas to the inlet side of the back filter, which is an exhaust gas treatment facility of the gasification melting furnace,
An effective utilization method of slag, characterized in that the fine slag is supplied to the inlet side of the vacuum filter as a reaction aid for the alkaline agent by air transportation means. The effective utilization method of the slag of Claim 1 or 2 whose particle size of the said fine grain slag is 0.075 micrometer or less. The method for effectively using slag according to any one of claims 1 to 3, wherein the fine slag is further pulverized after crushing to have an average particle size of 20 to 30 µm . A crusher for crushing the molten slag from the melting furnace attached to the incinerator;
A sieving machine for separating fine slag having scattering properties from molten slag crushed by the crusher ;
A bag filter which is an exhaust gas treatment facility for each of the incinerator and the melting furnace ;
Means for supplying an alkaline agent for neutralizing acidic gas in the exhaust gas to the inlet side of each of the back filters;
Pneumatic transportation means for blowing the fine slag into the inlet side of each bag filter as a reaction aid for the alkaline agent ;
A device for effectively using slag, characterized by comprising: A crusher for crushing molten slag from a gasification melting furnace;
  A sieving machine for separating fine slag having scattering properties from molten slag crushed by the crusher;
  A back filter as an exhaust gas treatment facility of the gasification melting furnace,
  Means for supplying an alkaline agent to the inlet side of the bag filter in order to neutralize the acid gas in the exhaust gas;
  Pneumatic transport means for blowing the fine slag into the bag filter as the reaction aid for the alkaline agent;
A device for effectively using slag, characterized by comprising: The said sieving machine is provided with the sieve mesh of 0.075 mm or less, The effective utilization apparatus of the slag of Claim 5 or 6 characterized by the above-mentioned. The slag effective according to any one of claims 5 to 7, further comprising a pulverizer for pulverizing the fine slag screened by the sieving machine into fine slag having an average particle size of 20 to 30 µm. Use device.

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