JPH0576360B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a waste melting furnace. More specifically, the present invention relates to a waste melting furnace equipped with a slag gutter self-cleaning mechanism for smoother sludge discharge in the melting process of waste such as municipal garbage incineration ash.

[Prior Art] Various wastes such as municipal garbage incineration ash, sewage sludge incineration ash, leather processing sludge incineration ash, etc. have conventionally been treated by landfilling or the like. However, due to the difficulty of securing land for landfill, and the risk that the hazardous heavy metals contained in the waste may be leached into the soil and contaminate the area surrounding the landfill site, causing secondary pollution, the waste A method has been proposed in which the above-mentioned problems are solved by melting the material in a melting furnace to render it harmless and reduce its volume. An arc type melting furnace is known as one type of melting processing furnace, and a typical example thereof is a submerged arc melting furnace.

This melting furnace consists of a furnace body with a fireproof structure equipped with a molten slag outlet, and a furnace lid equipped with a waste inlet, multiple main electrodes, a gas exhaust duct, etc.
This is equipped with a water crushing tank that receives the molten material discharged from the slag outlet, cools it, solidifies it, and crushes it. In addition, an auxiliary electrode for heating is arranged in the flow path of the molten material before the slag outlet, so that the molten material being discharged will not cool and solidify there and prevent the slag from being disposed of. The input port is open. Furthermore, a slag mouth weir brick with a U-shaped notch groove is replaceably fitted at the leading edge of the slag mouth.

Then, the lower end or about half of the entire length of the electrode is buried in the waste thrown into the furnace main body from the waste inlet, and by energizing the electrode,
Arc heat is generated, and the input waste is sequentially melted and discharged from the furnace through the U-shaped notch groove of the slag weir brick, cooled in a water crushing tank, and crushed into fine sand. solidified.

[Problems to be solved by the invention] The melting process using the submerged arc melting furnace is
As mentioned above, the lower end of the electrode or about half of its total length is buried in the waste to be processed, but as the waste is heated and melted, the level of the melting surface of the molten material in the furnace rises, causing The slag overflows to the outside of the furnace through the U-shaped notch groove of the slag weir brick provided at the slag opening, and is continuously drained by its own weight.

However, the slag gutter, which is the connection between the furnace main body of the slag outlet and the slag weir brick, is often clogged with unmelted materials during the melting process, making it impossible to smoothly discharge the slag.

Among municipal waste incineration ash, the molten slag produced when incineration ash of separated waste (unsuitable for combustion), which mainly consists of pins, is melted has a high viscosity and gas foaming property, and the melting level is low. It is easy to fluctuate during continuous melting process and continuous slag extraction. When the separated waste incineration ash is continuously processed, a film of unmelted material is formed in the slag drain of the melting furnace, causing congestion of the slag and increasing the level of molten slag in the furnace. In addition, the stamp material (refractory material) constituting the slag trough may be peeled off and mixed in the t. These jammed substances do not dissolve easily even if the auxiliary heating electrode is operated. As a phenomenon, a film of unmelted material made of solidified slag with a thickness of about 5 to 10 mm is formed in the slag drain, which prevents the molten slag from flowing smoothly.

[Means for Solving the Problems] The present invention was achieved as a result of various studies to solve the above problems. It can be easily crushed by simply giving
This is based on the knowledge that this allows the molten slag to flow out smoothly. That is, the present invention provides a sensor for detecting that unmelted substances are jammed and obstructing discharge on the slag gutter in front of the slag outlet of a waste melting processing furnace, and a sensor for removing the unmelted substances. The gist of the present invention is a waste melting processing furnace, characterized in that it is equipped with a self-cleaning mechanism for the slag gutter, which is equipped with a scraping rod that appears and retracts within the slag gutter.

[Operation] When the slag drain is clogged with unmelted material and the molten material is not being discharged outside the furnace, the scraping rod is activated based on the signal from the sensor that detects this and clears the slag drain. Perform self-purification. This eliminates the congestion of solidified slag and allows smooth continuous slag extraction.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 is a schematic side view of a submerged arc furnace, which is one example of a molten material melting processing furnace;
1 is a furnace body constructed of a refractory material containing one or more of carbon, magnesia, alumina, and the like. The upper surface of the furnace body 1 is covered with a furnace lid 2. A plurality of seed electrodes 3 pass through the furnace lid 2, and an inlet 4 for waste such as municipal rubber incineration ash and an exhaust gas duct 5 are provided. A slag outlet 6 is provided below the furnace body 1. The slag outlet 6 has a second opening which is an enlarged schematic front view seen from the direction of arrow A in FIG.
As shown in the figure, a fire-resistant slag weir brick 7 with a U-shaped notch structure 8 is provided, and the furnace body 1
The melt formed inside overflows from here and is slaged out of the furnace.

The entire bottom surface of the furnace body 1 is lined with a castable 1A made of a refractory material (stamp material), and the castable 1A is constructed in the form of a gutter near the slag outlet 6 to facilitate the discharge of the melt. It has been done.
On the slag drain, there is an auxiliary heating electrode 9 for preventing the molten material from solidifying in the normal slag, and a melting initiator inlet for charging the melting initiator 10 from the melting initiator storage hopper 11. 12 are provided. These auxiliary heating electrodes 9, melting initiator inlet 1
2 is placed on a slag outlet cover 13 that covers the slag outlet 6.

In the vertical direction of the slag outlet cover 13, that is, in the flow direction of the molten material, on the opposite side wall of the furnace body 1, there is a wall that passes through the slag outlet 6 and enters and retracts into the slag gutter (indicated by an arrow).
A scraping rod 15 of the self-cleaning mechanism 14 is provided with an inlet and an outlet for pulling out or crushing unmelted substances such as a solidified slag film remaining there. Furthermore, a detector 16 is provided below, that is, at the lower end of the slag weir brick 7, for detecting the state of discharge of the molten material from the slag outlet 6. etc. will be provided.

The self-cleaning mechanism 14 includes the scraping rod 15 and the sensor 1.
In addition to 6, a sensor 16 of a hydraulic cylinder 17 and a solenoid valve 18 that cause the scraping rod 15 to move in and out.
The controller 19 receives a detection signal from the controller 19 and operates and commands the hydraulic cylinder 17 to scrape out. Immediately below the slag outlet 6, there is a space for receiving the slag molten material,
A water pulverization tank 20 filled with water 19 for rapidly cooling and solidifying the water into fine particles is arranged.

The above-mentioned melting furnaces are improved versions of those originally used for pig iron, ferroalloys, copper, zinc, tin, etc., refining, and chemical products such as carbide, ferroalloys, and soluble ferrofertilizers. The furnace is operated while a current is introduced from the electrode 3 to generate a (submerged) arc between it and the waste or melt charged into the furnace. In the present invention, this can be suitably applied to the treatment of waste, particularly municipal rubber incineration ash, which has a basicity (CaO/SiO ₂ ) of 0.1 or less and a large glass content.

In the method of operating the furnace described above, first, incinerated ash a as waste is sequentially charged into the waste inlet 4 so as to have a uniform thickness, and is melted. Through this treatment, a molten material consisting of two layers is formed from the incineration ash a, a molten metal layer b mainly composed of metal components, and a molten slag layer c mainly composed of inorganic components, and the molten metal layer b, On top of that, a molten slag layer c is layered, and further on top of that, unmelted incineration ash a is layered.

The molten material (molten slag c) formed in the furnace body 1
The molten metal b) maintains a high temperature of 1,350 to 1,550°C, but when its volume increases due to continuous charging of incinerated ash a, the U-shaped notch groove 8 of the slag weir brick 7 of the discharge port 6 overflows from the flow, and as a downstream material d,
It falls into the granulated slag tank 20 and becomes granulated slag e.

A feature of the waste melting processing furnace of the present invention is that, while the molten material is being slaged out of the furnace, unmelted material is removed from the slag that is jammed on the slag gutter in front of the slag outlet 6 and prevents the molten material from being slaged smoothly. This is because a self-cleaning mechanism has been installed to remove the slag.

[Operation of the self-cleaning mechanism] The operation of the self-cleaning mechanism 14 will be explained with reference to the schematic side views showing the main parts enlarged in FIGS. 3 to 5. The slag is cooled in contact with the outside air on the trough and the surface becomes 5~5 thick.
A solidified film c1 of about 10 mm is formed. This stops the flow of the molten slag c on the slag drain and stops the slag (see Figure 3). In this case, the sensor 16 whose measurement point is the lower end of the slag weir brick 7 detects that the temperature of the molten slag c ranges from 1000° C. during normal continuous slag tapping.
1500℃ was detected, but when the flow of molten slag C is not detected and the slag stops, and a temperature other than a certain temperature, for example 600℃ or less, is detected, this is used as a detection signal and the control is started. The signal is transmitted to the device 19. The controller 19 has a temperature below a certain level (for example, below 600°C).
When receiving the above detection signal, an electrode lower operation command is issued to the lifting device (not shown) of the auxiliary heating electrode 9
An operating command for the electromagnetic valve 18 is input as a program, whereby the scraping rod 15 of the hydraulic cylinder 17 repeatedly moves forward and backward into the slag gutter through the slag outlet 6 for a certain period of time, and solidifies at its tip. Membrane c1
Crush (see Figure 4). As a result, the molten slag inside falls into the granulation tank 20 as a slag flow d,
The slag is restarted. As mentioned above, the solidified film c1 on the surface is relatively thin at 5 to 10 mm, and since the inside is molten slag, it is easily crushed, and the mechanical force of the scraping rod 15 is less than 5 kg/cm, which is an extremely light stress. nothing. When the slag extraction is resumed, the sensor 16 detects the normal sensing temperature again, and this signal causes the controller 19 to stop the operation of the scraping rod 15 relative to the solenoid valve 18 and to raise the auxiliary heating electrode 9. command and return to normal slag (see Figure 5).
In the above, an optical pyrometer is applied to the sensor 16 and the controller 19
Although the case has been described above in which a sequence using the ITV is incorporated, it goes without saying that a self-cleaning mechanism can be applied in which the ITV is used as the sensor 16 and the scraping rod 15 is manually moved in and out.

[Effects] Since the present invention has the above-described configuration, the melting level of waste, especially molten material, fluctuates drastically,
It is suitable as a processing furnace for incinerated ash of separated garbage, which is waste that tends to solidify slag in front of the slag outlet and clog the slag gutter, especially urban garbage with a low base content and incinerated ash.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic side view, FIG. 2 is a partially enlarged schematic front view seen from the direction of the arrow in FIG. 1, and FIGS.
The figure shows an enlarged schematic side view of essential parts showing the operating state of the melting furnace of the present invention. 1... Furnace body, 2... Furnace lid, 3... Main electrode, 4
... Waste inlet, 6 ... Slag outlet, 7 ... Slag weir, 8 ... Cut groove, 9 ... Auxiliary heating electrode, 14
... Self-cleaning mechanism, 15 ... Scraping rod, 16 ... Sensor, 17 ... Hydraulic cylinder, 18 ... Solenoid valve, 19 ... Controller.

Claims (1)

[Claims] 1 On the slag gutter in front of the slag outlet of the waste melting processing furnace,
A self-cleaning mechanism for the slag gutter is installed, which is equipped with a sensor that detects when unmelted materials are jamming and obstructing discharge, and a scraping rod that moves into the slag gutter to remove the unmelted materials. A waste melting processing furnace characterized by: