JPS6330074B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for melting incineration ash that has been incinerated in an incinerator for garbage and other waste.

[Conventional technology]

Conventionally, when incineration ash is melted,
As in Publication No. 44-29793, the incineration ash is disposed of by heating and melting in a heating furnace, which requires a large amount of heavy oil consumption and is uneconomical. This is lump ash mixed in incineration ash, such as cans,
The cause was the melting process of other metal products, ceramics, and other items containing high-melting-point substances.

[Problem that the invention seeks to solve]

In other words, powdered ash and lump ash have very different air permeability.
Powdered ash obstructs the passage of hot air, and N ₂ , O ₂ , CO ₂ and other gases contained in powdered ash and immovable all act as poor conductors of heat, making heating difficult.
Moreover, the lump ash contains ceramics and other foreign substances with a high melting point, and these are not discharged from the furnace and accumulate in the furnace, eventually forcing the operation to stop. On the other hand, if you try to form a stationary sedimentary layer mainly consisting of lump ash in the furnace and heat it to melt, some of the powdered ash will scatter and melt, but the hot air will flow in a biased direction, causing the deposited powder to melt. As mentioned above, ash has poor thermal conductivity, and hot air does not conduct heat and is discharged from the furnace at a high temperature, resulting in a waste of fuel. This is because it cannot be melted because it is included.

For this reason, it has been proposed in JP-A-52-131664 to store the ash in a container, form a stationary deposit layer, and treat it with high-frequency heating (micro heating), but the liquid molten material has metallic properties. , has the property of reflecting high frequency waves, so if it is placed in a container, stored and processed, a liquid melt is generated and reflects high frequency waves, so the high melting point substances contained therein (such as solids, metals, etc.)
It is inconvenient that it does not melt, microwaves do not penetrate into the lower part, and the heat radiated from the furnace wall solidifies from the bottom, making it impossible to operate.Workability is also extremely poor due to the batch method. Ta.

The present invention aims to eliminate these conventional drawbacks by extremely easily, continuously, and economically heating and melting only the powdered ash in the incinerated ash in a melting furnace.
The object of the present invention is to provide a method that can effectively utilize the molten material after treatment.

[Means for solving problems]

The present invention separates incineration ash generated from incineration ash into powdered ash and lump ash, and disperses and suspends the powdered ash by moving the powdered ash particles in an air stream at a terminal velocity or higher in a melting furnace. This is a method for melting incinerated ash, which is characterized by heating and melting it under conditions.

〔Example〕

If one embodiment of the present invention is explained with reference to the drawings, 1 is a powdered ash hopper, 2 is a fan, 3 is a melting furnace,
4 is a heavy oil burner, 5 is a molten ash outlet, 6 is incinerated ash, 7 is an ash separation screen, 8 is powdered ash, 9 is lump ash, 10 is a cyclone, and 11 is a cottle.

First, the incinerated ash produced by incineration with the incinerated ash 6 is separated into powdered ash and lumped ash (cans and other metal products) using an ash separation screen 7 such as a 1 mm sieve. Together with the powder components from the cyclone 10 and the Kottorel 11, the powdered ash is collected in the ash hopper 1 by a conveyor, and the ash is quantitatively cut out by the screw feeder 12 and transferred to the fan 2.
The powdered ash is guided into the melting furnace 3 on the air by the heavy oil burner 4, and at the same time, the powdered ash is released into the melting furnace 3 by the heavy oil burner 4, and at the same time, it is suspended in the furnace in a floating state (flushing) where it is dispersed and suspended in the air current. do. That is, the particle size of the powdered ash is reduced so that the relative velocity of the gas descending or rising through the heating reaction part in the melting furnace 3 and the powdered ash particles that have passed through the separation process almost matches the floating velocity of the powdered ash particles. The particles are moved at a terminal velocity or higher by reducing the floating velocity to create a suspended state in which powdered ash is dispersed and suspended in the airflow. In this state, the ash particles are exposed to the heavy oil twisting heat for only 1 to 5 seconds, preferably about 2 seconds, reaching a temperature of at least 1200℃ or more, and are heated and melted until they reach the bottom or wall of the furnace, becoming what is called smelt. and adheres to the inner wall of the furnace.
Eventually, it grows and flows down, and is continuously taken out of the furnace through the exhaust port. The smelt discharged outside the melting furnace 3 can be placed in a smelt receiver and made into blocks of an appropriate size, or dropped into water and made into granules, which can be used as road underlays, cement aggregates, etc. Exhaust gas in the melting furnace 3 is led to incineration ash 6 through a pipe 13 and treated.

The above-mentioned dispersed suspension state means that the air flow velocity direction is up and down,
It can be in either the left or right direction, and refers to a state in which particles are made to move at a speed higher than their terminal velocity.In a fluid state, particles are given an upward flow velocity from below, and this upward flow velocity is caused to move at 0.1 to 0.4 times the terminal velocity. is different. Note that the terminal velocity is determined by the particle size, specific gravity, and shape, so it is important to go through a separation process to separate the incinerated ash into powdered ash and lump ash. In the illustrated example, powdered ash of 150 μm or less is entrained in the airflow using the fan 2 and supplied into the melting furnace 3, but the powdered ash is accelerated and dispersed in the airflow using a powder burner using an ejector effect. , can also be suspended.

In the figure, 14 is a dust inlet, 15 is a flue, 16 is an exhaust fan, 17 is a chimney, and 18 is a dust return channel.

In addition, glassy components etc. are extracted from the lump ash,
This can also be pulverized and mixed into powdered ash for melting treatment. In addition, in the separation step, the ash is separated into powdered ash and lump ash, and only the powdered ash is melted, and the lump ash is completely separated and processed separately.
It is also possible to dispose of it. In this case, the heating and melting of powdered ash in a state of dispersion and suspension in an air stream can be carried out by feeding powdered ash and fine lump ash into the furnace.

〔Effect of the invention〕

According to the present invention, incineration ash is separated and powdered ash is heated and melted in a floating state in which the powdered ash particles are moved at a terminal velocity or higher in an airflow in a melting furnace and dispersed and suspended in the airflow, thereby generating heat. Increase surface/mass,
The input material instantly rises to ambient temperature and can be continuously heated and melted very easily and economically with a small amount of fuel, and the apparent specific gravity of the molten material is 2.0 times, which is about four times that of conventional simple incineration ash. The hardened waste has a hardness higher than that of rock, and can be used as solid ground for landfill, with no harmful metals leaching out.It can also be used satisfactorily as aggregate for concrete, greatly improving disposal efficiency, and can be incinerated. By separating the unique lumpy ash from the ash, the powdered ash can be made uniform and compositional fluctuations can be reduced, and by separating the powdered ash and lumpy ash, the melting point can be set to a low value and workability can be greatly improved. In addition, operation management is simplified and stable incineration ash processing becomes possible.

[Brief explanation of the drawing]

The drawing is a system explanatory diagram showing one embodiment of the present invention. 1... Powdered ash hopper, 2... Fan, 3... Melting furnace, 4
...Heavy oil burner, 5...Melted ash outlet, 6...Incineration ash, 7...Ash separation screen, 8...Powdered ash, 9...Lump ash, 10...Cyclone, 11...Cottle, 12
... Screw feeder, 13... Piping, 14... Dust inlet, 15... Flue, 16... Exhaust fan, 17... Chimney, 18... Dust return channel.

Claims (1)

[Scope of Claims] 1. After a separation step in which incinerated ash generated from an incinerator for waste such as garbage is separated into powdered ash and lump ash, the powdered ash is placed in a melting furnace and the powdered ash particles are terminated in an air stream. A method for melting incineration ash, which is characterized by heating and melting the ash by moving it at a speed higher than that in a suspended state in which it is dispersed and suspended. 2. The method for melting incinerated ash according to claim 1, wherein the heating and melting step maintains the dispersed and suspended state of the powdered ash within 2 seconds to complete the heating and melting. 3. The method for melting incinerated ash according to claim 1 or 2, wherein in the heating and melting step, the glassy components in the lump ash are mixed into powdered ash in the form of fine powder and melted.