JPH0839036A - Melt treatment apparatus for fly ash - Google Patents

Abstract

PURPOSE:To prevent fly ash in a treatment process from scattering, to reduce the volume of exhaust gas by reducing the volume of accompanying air into a melting furnace, to collect mercury, etc., efficiently to make the treatment of exhaust gas easy, and to improve the melting efficiency. CONSTITUTION:In the reduction of volume of fly ash by melting treatment, an apparatus is equipped with a kneader 3 for kneading the fly ash with water, a pelletizing means 5 for the kneaded product, a dryer 6 for solidifying the pellets by evaporating water, a supply means 8 for material to be melted, and a melting furnace 9 for melting and treating the material to be melted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for melting fly ash, and more particularly, to melting and processing fly ash discharged from a waste incinerator for incinerating municipal solid waste, industrial waste, etc. in a melting furnace. In this case, the present invention relates to a technique for efficiently melting the fly ash while preventing the fly ash from scattering.

[0002]

2. Description of the Related Art As an example of an incinerator for incinerating incinerators such as municipal waste, there is proposed a fluidized bed type incinerator of No. Kaikaihei 3-56027. Further, the following proposals have been made as related technology examples of melting and processing fly ash (dust) in a melting furnace. JP-A-58-030382 "Dust processing method" JP-A-58-040791 "Slag method" JP-A-60-053780 "Electrode insertion control device for direct current type melt processing furnace" JP-A-60- No. 054780 “Melting treatment furnace for dust” JP-B-63-051755 “Dust treatment method” JP-A-63-315187 “Incinerator exhaust gas treatment method” JP-A-02-099184 “Detoxification treatment of heavy metal-containing dust” Method ”In these technologies, when fly ash (dust) discharged from incinerators such as municipal solid waste is melted and solidified in a melting furnace, various problems that occur during melting are solved. There is.

[0003]

According to the melt processing technology of these dusts, fly ash (dust) is directly supplied to the inside of the melting furnace as described in the prior art example. Therefore, fly ash is scattered inside the melting furnace and the amount of mixing in the exhaust gas is large, and a large amount of air is sent into the melting furnace together with the fly ash, and a large amount of exhaust gas from the melting furnace is generated. Due to these factors, there remains a problem that a complicated and high-performance exhaust gas treatment facility is required.

The present invention has been made in view of the above circumstances, and achieves the following objects. a) To prevent fly ash from scattering inside the melting furnace and during supply to the melting furnace. b) To reduce the amount of exhaust gas by reducing the amount of fly ash entrained in air. c) To improve the melting efficiency of fly ash. d) To reduce fluctuations in fly ash supply. e) By guiding the mercury and the like mixed in the fly ash to a stable state,
To achieve simplification of exhaust gas treatment facilities.

[0005]

[Means for solving the problems] As a fly ash melting treatment device for melting and reducing the volume of fly ash produced by incinerating garbage, industrial waste, etc., it is kneaded by adding water to fly ash. Kneader for imparting viscosity, granulation means connected to the kneader for making kneaded products into a plurality of small pieces, and connected to the granulation means for evaporating water to solidify the small pieces A drier, a melted material supply means connected to the drier for transferring the solidified melted material, and a melting furnace connected to the melted material supply means for melting the melted material. The configuration is adopted. The kneader, configuration Na ₂ S aqueous solution supply system by applying a Na ₂ S solution to impart fluidity to the fly ash is connected is added. The granulating means includes a nozzle part that pushes and releases the kneaded material sent out from the kneader to make a plurality of small agglomerates by rupture at the time of dropping, and a small agglomerate disposed below the nozzle part for drying the small agglomerates. A configuration in which a transfer means for transferring the inside is arranged is added. A belt conveyer or the like is adopted as the transfer means, whereby the nozzle portion and the melted material supply means are connected.

[0006]

[Operation] Fly ash produced by incinerating waste, industrial waste, etc., is given a viscosity by kneading in a state where water is added, and the granulation means breaks the kneaded product into granules. It is done and it becomes a plurality of small pieces. The small lumps are sent to a drier to remove water and become a solidified melted material, which is sent to a melting furnace by a melted material supply means and reduced in volume by a melting process. When a material to be melted in the melting furnace is generated, the occurrence of a scattering phenomenon is suppressed due to the solidification of fly ash, and the amount of air entrained is reduced. When an aqueous Na ₂ S solution is used to supply water when forming the kneaded product, mercury and mercury salts mixed in the fly ash become solid HgS by the following chemical reaction and become in a stable state. . HgCl ₂ + Na ₂ S → HgS + 2NaCl In the granulating means, the kneaded material is pushed down and dropped into a plurality of small agglomerates, and these small agglomerates are received by a transfer means such as a belt conveyor. Then, the melted material is transferred to the means for supplying the material to be melted.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the fly ash melting apparatus according to the present invention will be described below with reference to FIG. In FIG. 1, reference numeral 1 is a refuse incinerator, 2 is a fly ash hopper, 3 is a kneader, 4 is a kneading liquid supply means, 4A is a water supply system, 4B is a Na ₂ S aqueous solution supply system, 5 is a granulation means, 5A is a nozzle part, 6 is a drier, 7 is a transfer means (belt conveyor), 8 is a material to be melted supply means, 9 is a melting furnace, and 10 is an exhaust gas treatment system.

The waste incinerator 1 is applied with, for example, the actual fluidized bed incinerator No. 3-56027 "fluidized bed type incinerator" cited as an example of the prior art, and fly ash produced by incinerating garbage, industrial waste, or the like. A is sent to the fly ash hopper 2.

The fly ash hopper 2 is disposed between the refuse incinerator 1 and the kneader 3, and the fly ash A is temporarily stored and supplied in appropriate amounts.

The kneader 3 is disposed between the fly ash hopper 2, the kneading liquid supply means 4, the granulating means 5 and the drier 6 so that the fly ash A is mixed with water. To form a viscous substance having viscosity.

[0011] The kneading liquid supply means 4, a water supply system 4A for supplying water alone, and Na ₂ S aqueous solution feed system 4B for supplying Na ₂ S aqueous solution commensurate with HgCl ₂ contained in the fly ash A , And control valves 4a and 4b for controlling the supply of these liquids.

The granulating means 5 comprises a kneader 3 and a dryer 6.
And a nozzle portion 5A for forming a part of the downstream of the granulating means 5 to push out the kneaded material and release the support to free fall, and below the nozzle portion 5A. And a transfer means (belt conveyor) 7 that receives the small lumps B when the kneaded material exceeds the load supporting force of the kneaded material and breaks.

The dryer 6 is arranged so as to surround the transfer means 7, and has a power supply 6a for supplying power, a power control section 6b for controlling the amount of power supply, and a transfer means for transferring the small quantity. It has a heater 6c for heating and drying the lump B to form the melted material C, and a fan 6d for generating an air flow to accelerate the drying.

The transfer means 7 is arranged so as to connect the nozzle portion 5A and the melted material supply means 8 and is constituted by a belt conveyor or the like as described above.

The material to be melted supply means 8 is arranged between the downstream of the transfer means 7 and the charging port 9a of the melting furnace 9 and is solidified by passing through the dryer 6. It has a chute 8a for supplying the melted material C so as to drop it into the charging port 9a, and a guide cover 8b for preventing the melted material C from jumping out and guiding it downward.

As the melting furnace 9, for example, a direct current type melting furnace described in the prior art example is applied, and the exhaust gas generated by melting the material C to be melted charged from the charging port 9a is exhausted. 9b downstream exhaust gas treatment system 1
I try to send it to 0.

In the fly ash melting apparatus having the above-mentioned structure, the fly ash A produced by incinerating dust, industrial waste and the like in the refuse incinerator 1 is the fly ash hopper 2. Fly ash A from the fly ash hopper 2
And the water from the kneading liquid supply means 4 are supplied to the kneading machine 3 and kneaded to form a kneaded product having viscosity.

[0018] At this time, the supply of Na ₂ S aqueous solution from Na ₂ S aqueous solution supply system 4B, the equivalent to HgCl ₂ N
When a ₂ S is reacted, mercury and / or mercury salt and Na ₂ S
The following chemical reactions take place during the production of solid HgS. HgCl ₂ + Na ₂ S → HgS + 2NaCl

The kneaded material to which viscosity is imparted by kneading is
Although it is extruded in a rod shape from the nozzle portion 5A, it hangs down due to its own weight, and when the weight of the hanging portion exceeds the supporting force based on the viscosity, it is naturally cut (broken) and becomes a columnar small lump B. And is dropped onto the transfer means 7.

The small lump B is dried by the transfer means 7 by the dryer 6.
By being sent into the interior of the container and heated, the water content is removed and the melted material C in the solidified state is transferred to the melted material supply means 8.

In the melted material supply means 8, the melted material C transferred by the transfer means 7 is collected by the chute 8a while being prevented by the guide cover 8b.
The material C to be melted is supplied into the melting furnace 9 so as to be dropped from the charging port 9a. The supply amount at this time is 3
And the driving speed of the granulating means 5 is set, and when the kneading machine 3 and the granulating means 5 are in a constant speed operation state, a fixed amount is supplied.

The melted substance C supplied to the melting furnace 9 is reduced in volume by being heated and melted. By solidifying the fly ash, the fly ash is treated with the exhaust gas from the exhaust port 9b. The occurrence of the phenomenon of being sent to the system 10 is suppressed. In addition, the solidification of the fly ash causes the melting furnace 9
Since the amount of air entrained in the inside of the melting furnace is reduced, the apparent specific gravity can be increased to increase the amount of sinking into the melt inside the melting furnace 9. Induction is performed.

By converting Hg and HgCl ₂ into HgS, HgS is mixed in the melt to prevent the HgS from being sent into the exhaust gas, and even when HgS is sent to the exhaust gas treatment system 10, Since it can be collected as a substance, it is possible to reduce the load on the exhaust gas treatment system 10 during the melt volume reduction treatment when the fly ash contains Hg.

[0024]

The apparatus for melting fly ash according to the present invention has the following effects. (1) A kneader for adding water and kneading when melting and reducing the volume of fly ash, a granulating means for making kneaded products into a plurality of small particles, and a small particle for evaporating water By adopting a configuration that includes a dryer for solidifying the melt, a material to be melted, and a melting furnace for melting and processing the material to be melted, fly ash is prevented from scattering inside the melting furnace and during the supply to the melting furnace. Can be prevented. (2) By solidifying the fly ash, the air contained in the fly ash is eliminated, the amount of air entrained in the melting furnace is reduced, the amount of exhaust gas is reduced, and the melting efficiency can be improved. (3) Granulation of the fly ash and supplying it to the melting furnace can reduce fluctuations in the melting rate of the fly ash. (4) By adding a Na ₂ S aqueous solution supply system to the kneader, water is supplied together with Na ₂ S, and mercury etc. mixed in the fly ash is stabilized in HgS and mixed in the melt. Even when HgS is sent to the exhaust gas, the collection and treatment can be easily performed. (5) As the granulating means, a nozzle portion for extruding and releasing the kneaded material to drop it into a plurality of small chunks, and a transfer means for transferring the kneaded matters into the dryer while receiving the small chunks are provided. Thereby, the structure of the granulation portion can be simplified.

[Brief description of drawings]

FIG. 1 is a block connection diagram showing an embodiment of a fly ash melting processing apparatus according to the present invention.

[Explanation of symbols]

1 Waste incinerator 2 Fly ash hopper 3 Kneader 4 Kneading liquid supply means 4A Water supply system 4B Na ₂ S aqueous solution supply system 4a, 4b Control valve 5 Granulation means 5A Nozzle part 6 Dryer 6a Power supply 6b Power control part 6c Heater 6d fan 7 transfer means (belt conveyor) 8 melted material supply means 8a chute 8b guide cover 9 melting furnace 9a input port 9b exhaust port 10 exhaust gas treatment system A fly ash B small lump C melted material

Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number of the agency FI Technical display location F27B 3/18 F27D 13/00 Z 8926-4K H05B 3/60 7512-3K 7/20 (72) Inventor Umeda Tojiro, Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa, Ishikawajima-Harima Heavy Industries Co., Ltd. Technical Research Institute (72) Inventor, Kenji Sakurai Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa Pref., Ishikawajima-Harima Heavy Industries Co., Ltd.

Claims (3)

[Claims] 1. A method for melting fly ash (A) produced by incinerating refuse, industrial waste, etc. to reduce its volume, and adding water to the fly ash to knead it to give viscosity. A kneading machine (3), a granulating means (5) connected to the kneading machine to turn the kneaded material into a plurality of small agglomerates, and connected to the granulating means to evaporate water to form a small agglomerate. A dryer (6) for solidifying,
A melted material supply means (8) connected to the dryer for transferring a solidified melted material (C), and a melting furnace (9) connected to the melted material supply means for melting and processing the melted material. An apparatus for melting fly ash, comprising: 2. A kneader (3), Na ₂ S aqueous solution supply system to impart fluidity to impart Na ₂ S solution in fly ash (4
B) is connected, The melting processing apparatus of the fly ash according to claim 1. 3. A granulating means (5), a nozzle part (5A) for extruding and releasing a kneaded material sent from a kneading device (3) to form a plurality of small agglomerates by rupture when dropped, and the nozzle. The fly ash melting treatment apparatus according to claim 1 or 2, further comprising a transfer means (7) which is arranged below the portion and transfers the small lumps into the dryer (6).