JPS6212475Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an ash solidification device in a municipal waste incinerator, and particularly relates to an ash solidification device capable of molding a molded product from which harmful substances contained therein are not eluted.

FIG. 1 is a flowchart of a conventional municipal waste incineration system, and as shown, two types of ash are discharged from an incinerator for municipal waste. That is, the incinerated ash has a relatively large mass and falls from the gap between the rotors in the incinerator body, and the fine collected ash is scattered in the combustion exhaust gas and collected by the dust collector. The former contains heavy metals such as cadmium, lead, and zinc, and the latter contains chloride, both of which are harmful, so dumping them directly into a landfill will harm the health of surrounding residents and damage crops. will have a significant impact on

Conventionally, as shown in Figure 1, calcium hydroxide in the form of a slurry is sprayed into the exhaust gas in the flue leading from the furnace main body to the gas cooling chamber, the heat exchanger, and the dust collector. Hydrogen chloride and calcium hydroxide are reacted to fix hydrogen chloride in the form of calcium chloride, which is collected by a dust collector, and this collected dust ash and incinerated ash from the furnace body are collected together with water and cement. After kneading, the kneaded product is formed into granules similar to charcoal using a molding machine, temporarily stored in a molded product pit, and then disposed of in a landfill.

In this way, by solidifying the discharged ash with cement, metals in the discharged ash can be fixed, but the elution of chlorides cannot be prevented, and this method is not perfect as a treatment method for pollution-causing substances. Ta.

Therefore, the inventor of this invention formed a coating of resin, waterproof mortar, etc. on the surface of the molded product made from the ash discharged from the incinerator, and then dried this coating using the residual heat of the incinerator's exhaust gas. The authors discovered that it is possible to prevent the release of chloride, and devised a device suitable for this purpose.

In particular, this idea forms a film on the surface and transports the molded product to a position facing the gas cooling chamber, where the remaining heat dries the film.The temperature of the gas cooling chamber is 200°C because water is sprayed. ~300°C, and the aim is to carry out the drying process smoothly at an appropriate temperature without the risk of the film melting and vaporizing due to high-temperature gas.

This invention will be explained in detail below with reference to embodiments shown in the accompanying drawings.

FIG. 2 is a flowchart of a municipal waste incineration system including the ash solidification device according to the invention, and FIG. 3 is a vertical sectional view showing an outline of the ash solidification device.

As is clear from comparing FIG. 1 and FIG. 2, the feature of the present invention lies in the process from the molding machine to the molded product pit, and in other respects it is the same as the known technology.

In Fig. 3, 20 is a kneaded material obtained by charging incineration ash and collected dust ash accumulated on a conveyor into a kneader together with cement and water in an appropriate ratio and mixing them. 2) is conveyed by the conveyor 22, and is fed into the molding machine 24 from the hopper 26. The molding machine 24 has a known structure,
Two rolls 28, 28 having bowl-shaped recesses (not shown) at corresponding positions on the peripheral surfaces are arranged side by side, and when the kneaded material passes between the peripheral surfaces of both rolls, it is formed into granules by the bowl-shaped recesses. be done.

The molded article 29 formed in this manner falls onto a conveyor 30, is conveyed by the conveyor 30, passes through a chute 32, and falls and settles into the resin liquid 35 in the resin tank 34.

The resin tank 34 is configured as a conveyor trough 34, and the resin liquid 35 is stored at the rear end of the trough 34, and the trough 34 extends obliquely upward to reach the lower part of the gas cooling chamber 12. An opening 38 is opened upwardly in the gas cooling chamber 12 to communicate with the inside of the gas cooling chamber 12 . A chute 37 is provided at the front and rear of the trough 34. Chute 3 connected to conveyor 30
2 is the trough 3 from the opening provided in the trough 34 canopy.
4, and its lower end is formed in a water-seal type with its lower end immersed in the resin liquid 35. The conveyor 36 is not shown in detail, but the chains 31, 31 on both sides
A large number of scrapers 33 are arranged between the
The molded product 29, which falls into the resin liquid 35 through the chute 32 and whose surface is coated with resin, is scooped up and conveyed, and passed through the lower part of the gas cooling chamber 12 to a temperature of 200° C.
The resin film is dried and solidified at a temperature of 300°C. Thereafter, the molded product 29 is discharged from the trough through the chute 37, sent to a molded product pit (not shown), stored therein, and then disposed of in a landfill.

Reference numeral 39 denotes a resin feeder, which is not shown in the drawings, but has a liquid tank with inner lining and an agitator attached, and supplies the resin liquid 35 by appropriate means.
into the trough 34.

In addition, 10 is a furnace main body, 14 is a nozzle for cold water injection arranged in the upper part of the gas cooling chamber 12, and 16 is a duct through which the exhaust gas and the water vapor of the water sprayed from the nozzle 20 flow in the direction of the heat exchanger.

In the above example, a resin liquid was used as the surface coating agent for the molded product, but in this case, it is necessary to select a type of resin that solidifies without evaporating at the temperature of 200°C to 300°C in the gas cooling chamber 12. is necessary. Further, instead of the resin, a waterproof mortar or other film forming agent may be used.

As described above, in this invention, the ash discharged from the incinerator is mixed with cement and water, the molded product is molded using a molding machine, and the molded product is sent into a tank containing a film-forming agent, and the surface is coated with resin. By forming a film with waterproofing agent mortar, etc., and passing this through the part facing the gas cooling chamber of the incinerator using a conveyor, the appropriate residual heat dries the film and hardens the solids. ing. As a result, the metals contained in the discharged ash are fixed by solidification with cement, and the elution of harmful substances such as chlorides contained in the discharged ash is prevented over a long period of time by the coating formed on the surface. This can be reliably prevented, and furthermore, the drying of the coating and the curing of the solid material can be performed economically.

[Brief explanation of the drawing]

Fig. 1 is a flowchart showing a conventional municipal waste incineration system, Fig. 2 is a flowchart of an incineration system including an ash solidification device according to the present invention, and Fig. 3 is a flowchart showing an ash solidification system according to the present invention. FIG. 2 is a schematic longitudinal cross-sectional view of the device. Explanation of symbols, 10... Incinerator main body, 12... Gas cooling chamber, 20... Kneaded material, 24... Molding machine, 2
9...Molded product, 32...Water-sealed chute, 34...
...Film forming agent tank (trough), 35... Film forming agent liquid, 36... Conveyor (flight conveyor), 3
8...Opening.

Claims (1)

[Scope of utility model registration request] A molding machine 24 that molds a kneaded material 20 obtained by kneading discharged ash from an incinerator with cement and water, and a molded product 2
a tank 34 of film-forming agent receiving 9;
A conveyor 36 transports the molded product 29 inside to a point facing the inside of the gas cooling chamber 12 connected to the incinerator main body 10. A water-sealed chute 32 is provided for feeding the molded product 29 into the trough 34, and
The ash solidification device in a municipal waste incinerator is characterized in that the trough 34 has an opening 38 at a location facing the cooling chamber 12.