JPH0526092B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a starting method for heating and melting incineration residue.

[Conventional technology]

Generally, garbage thrown away from homes and businesses is incinerated in a garbage incinerator, and the incineration residue left in the incinerator is used for landfill.

However, as urbanization progresses, the amount of municipal waste is increasing, and landfilling cannot be done indefinitely, so it is desired to reduce the volume of incineration residue.

As a method for reducing the volume of incineration residue, a method has conventionally been proposed in which the incineration residue is heated and melted using an electric furnace and then solidified.

According to this method, since the incineration residue is a conductor in the molten state (molten residue), once the molten residue is generated, the electrode is brought into contact with the molten residue and energized to generate resistance heat, so that it can be thrown in. The incineration residue can be heated and melted with the molten residue, and the melting process can be carried out continuously.

However, since the incineration residue is a nonconductor in a solid state, at startup when the molten residue has not yet been generated, it is necessary to heat and melt the incineration residue by some other method to generate the molten residue.

Conventionally, various methods have been used to start the system, including the following.

(a) Put the incineration residue into the heating furnace and place the electrodes so that they are floating above the incineration residue. In this state, an arc discharge is generated between the electrodes, and the incineration residue in the vicinity is melted by the arc heat.

(b) Add a conductive material to start melting the incineration residue and put it into the heating furnace, bring the electrode into contact with the incineration residue, and apply electricity through the conductive material to melt the incineration residue by resistance heat generation. do.

(c) The electrode spacing is made variable, and at startup, incineration residue is put into the heating furnace, and the electrode spacing is narrowed (in other words, making it easier to cause arc discharge), causing arc discharge between the electrodes, and the arc The heat will melt nearby incineration residue. After activation, the electrodes are separated to a predetermined distance.

(d) A conductor component is placed in a heating furnace, an electrode is brought into contact with the conductor component, and electricity is applied to generate resistance heat, and incineration residue is placed on top of the conductor component, and the incineration residue is melted by the heat of the conductor component.

[Problem to be solved by the invention]

According to the method (a) above, there was a drawback that a high voltage was required to cause arc discharge between electrodes that were spaced apart.

According to method (b) above, simply adding a conductive material to the incineration residue does not necessarily ensure the formation of a current path for resistive heat generation, and it is not possible to start up the device reliably. Moreover, since the conductor components are heated by resistance heat generation, it is difficult to obtain high temperatures and it takes time to start up.

According to the method (c), a drive mechanism is required to vary the electrode spacing, which has the disadvantage of complicating the configuration.

According to method (d) above, since the conductor component is heated by resistance heat generation, it is difficult to obtain a high temperature and it takes time to start up.

The present invention solves the problems in the conventional technology, does not require high voltage to cause arc discharge, can be started reliably, does not have a complicated configuration, and can be started in a short time. The present invention aims to provide a method for starting the heating and melting of incineration residue.

[Means to solve the problem]

In the present invention, a conductor component is put into a heating furnace, an electrode is placed in a non-contact state with the conductor component, an arc discharge is caused between the electrode and the conductor component, and the arc heat causes the inside of the heating furnace. After that, the incineration residue is put into the heating furnace, and the heat in the heating furnace is used to heat and melt it to generate a conductive molten residue, and the electrode is brought into contact with the molten residue and energized. This method is characterized in that the molten residue is subjected to resistance heating, and the incineration residue that is subsequently charged into the heating furnace is heated and melted by the molten residue that has been subjected to resistance heating.

[Operation] According to the present invention, a conductor component is put into the heating furnace, and an arc discharge is generated between the electrode and the conductor component to heat the inside of the heating furnace and start up. The arc length can be shortened compared to the method of starting by causing an arc discharge between electrodes, which makes arc discharge more likely to occur and eliminates the need for high voltage.

In addition, instead of adding a conductive component to the incineration residue, the incineration residue is directly put into the heating furnace and heated by generating an arc discharge between the incineration residue and the electrodes. Compared to a method that generates resistance heat by passing current through a conductive material, startup can be performed more reliably.

Also, since arc discharge is generated between the electrode and the conductor component to heat the inside of the heating furnace, the inside of the heating furnace is heated by heating the conductor component with resistance heat generation as in (b) and (d) above. Compared to the conventional method, a high temperature can be obtained, which allows the incineration residue to be melted in a short time, and the start-up time can be shortened.

Furthermore, unlike the method (c) above, there is no need to vary the electrode spacing in order to facilitate arc discharge, so the configuration is simple.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a flow sheet diagram showing an example of the method of the present invention, and FIG. 2 is an explanatory diagram showing the specific steps step by step. First, a conductor component 1 such as a carbon-based solid material or a metal component whose specific gravity is smaller than that of the melted residue is placed in a heating furnace 2 . Then, as shown in FIG. 2a, a three-phase high voltage is applied to each of the three electrodes 3A to 3C attached to the heating furnace 2 so as to be close to the conductor component 1. An arc discharge is generated between the two, and the inside of the heating furnace 2 is heated by the arc heat at a temperature of about 4000°C.

After the inside of the heating furnace 2 reaches a high temperature state (for example, 1350° C. or higher), an appropriate amount of garbage incineration residue 4 is put into the heating furnace 2 as shown in FIG. Residue 4 is heated and melted. Although the incineration residue 4 is a nonconductor, it becomes a conductor by melting it to form a molten residue. Next, as shown in FIG. 2C, the molten residue 5 and the electrodes 3A to 3C are brought into contact and electricity is applied between the electrodes 3A to 3C, that is, the molten residue 5,
This causes resistance to heat up.

Then, as shown in FIG. 2D, the incineration residue 4
The incineration residue 4 that is subsequently put into the heating furnace 2 is
It is heated and melted by the heat generated by the resistance.
Thereafter, the molten residue 5 is similarly energized to generate resistance heat.
The heat is used to heat the incineration residue 4, and in this way, the incineration residue 4 is continuously charged and continuously melted. On the other hand, the molten residue 5 is continuously taken out from the outlet of the heating furnace 2 and sent to the next step, where it is cooled and solidified by methods such as water pulverization, air pulverization, and air cooling. Regarding the input of the incineration residue 4, the incineration residue 4 is temporarily stored in a storage pit, and from there it is transferred to the heating furnace 2 via a conveyor, hopper, and chute.
It can be inserted inside.

Here, the conductor component 1 is for melting the incineration residue 4 initially put into the heating furnace 2, and once the molten residue 5 is formed and resistance heating is performed, it becomes unnecessary thereafter. As the conductor component 1, it is preferable to use a material having a specific gravity smaller than that of the molten residue 5.

The reason for this is that when a metal with a higher specific gravity than the molten residue (specific gravity of about 2 to 3), such as iron scrap (specific gravity of about 6.5 to 6.8), is used as the conductor component 1, the molten metal sinks below the molten residue 5. Collects at the bottom.
Molten metal that accumulates at the bottom of the furnace solidifies during a power outage, but
Since it contracts at this time, there is a risk of damaging the hearth or hearth bottom, and it may not be possible to restart operation when the power is restored, which may impede continuous operation. It is also possible to withdraw the molten metal from the heating furnace 2 in order to avoid solidification at the bottom of the furnace, but in this case, molten metal processing equipment such as a ladle, pig iron casting machine, or ingot processing machine is required, which increases the equipment cost. is required. On the other hand, if a material with a specific gravity smaller than that of the molten residue 5 is used as the conductor component 1, for example, carbon-based solids such as breeze (charcoal powder), coke or carbon electrode scraps, or non-ferrous metals such as aluminum, the conductor can be formed. Component 1 is dissolved in the melted residue 5 and taken out together with it. Furthermore, in the case of carbon-based solids, a portion of them is scattered into the atmosphere. Therefore, there are no problems such as those mentioned above, and there is no fear that continuous operation will be hindered even if no special molten metal processing equipment is provided. Incidentally, even if the melted residue 5 solidifies during a power outage, it will not shrink, so there is no risk of damaging the hearth or furnace wall.

〔Effect of the invention〕

As described above, according to the present invention, a conductor component is put into the heating furnace, and an arc discharge is generated between the electrode and the conductor component to heat the inside of the heating furnace and start. The arc length can be shortened compared to the method of generating and starting, which makes arc discharge more likely to occur and eliminates the need for high voltage.

In addition, instead of adding a conductive component to the incineration residue, the incineration residue is directly placed in the heating furnace and heated by generating arc discharge between the incineration residue and the incineration residue. Startup can be performed more reliably than a method that generates heat through resistance by applying electricity.

In addition, since arc discharge is generated between the electrode and the conductor component to heat the inside of the heating furnace, a higher temperature can be obtained compared to the method of heating the inside of the heating furnace by heating the conductor component using resistance heat generation. Incineration residue can be melted in a short time, and startup time can be shortened.

Furthermore, since there is no need to vary the electrode spacing to facilitate arc discharge, the configuration is simple.

[Brief explanation of drawings]

FIG. 1 is a flow sheet diagram showing an embodiment of the method of the present invention, and FIGS. 2A to 2D are explanatory diagrams showing step-by-step concrete process examples. DESCRIPTION OF SYMBOLS 1... Conductor component, 2... Heating furnace, 3A-3D... Electrode, 4... Incineration residue, 5... Melting residue.

Claims (1)

[Claims] 1. A conductive component is placed in a heating furnace, an electrode is placed in a non-contact state with the conductive component, an arc discharge is caused between the electrode and the conductive component, and the arc heat causes the The inside of the heating furnace is heated, and then the incineration residue is put into the heating furnace, and it is heated and melted by the heat in the heating furnace to generate a conductive molten residue, and the electrode is brought into contact with this molten residue. A method for starting heating and melting of incineration residue, characterized in that the molten residue is resistively heated by applying electricity, and the incineration residue that is subsequently charged into the heating furnace is heated and melted with the molten residue that has been generated resistance heat.