JP2718761B2 - Industrial waste melting furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention connects an exhaust passage of industrial waste slag melted in a high-temperature hearth formed of a carbon-based combustible material to a furnace bottom, and exhausts flue gas. An industrial waste melting furnace in which a passage is connected above the high-temperature hearth and a tuyere for supplying oxygen-containing gas for combustion to the high-temperature hearth is connected above the discharge passage of the slag. The present invention relates to improvement of technology for preventing poor slag discharge (defective slag).

To further explain, in a portion located below the tuyere in the slag flow path from the high-temperature hearth to the discharge path,
Since the heat generated from the high-temperature hearth decreases, a change in the melting temperature due to a change in the type of industrial waste, the appearance of a low-temperature region due to a change in operating conditions, etc. tend to cause poor flow due to an increase in the viscosity of the slag. The present invention relates to a technique for preventing such troubles if the slag is solidified if left as it is and slag cannot be removed.

[Conventional technology]

Conventionally, when a slag defect occurs, an iron pipe is artificially inserted into the discharge path, oxygen gas is blown from the iron pipe into the furnace, and the tip of the iron pipe is oxidized by the oxygen gas, thereby generating heat due to the oxidation. Melts the slag that has been increased in viscosity or consolidated, thereby eliminating defective slag.

[Problems to be solved by the invention]

However, inserting an iron pipe into the discharge path near a high-temperature furnace is dangerous, especially when the highly viscous or solidified slag is melted and burns due to hot air blowing or coke, etc. There was room for improvement in safety.

In addition, if the slag is thickened or consolidated in a narrow gap such as coke in a high-temperature hearth, it is difficult to insert an iron pipe into the narrow gap, and it is difficult to eliminate defective slag and it takes a long time. However, there is still room for improvement in workability.

SUMMARY OF THE INVENTION An object of the present invention is to enable safe, easy, and quick execution of slag defect prevention treatment.

[Means for solving the problem]

The characteristic configuration of the present invention is that the discharge path of the industrial waste slag melted in the high-temperature hearth formed of the carbon-based combustible material is connected to the furnace bottom, and the exhaust path of the combustion exhaust gas is connected above the high-temperature furnace. In an industrial waste melting furnace in which a tuyere for supplying oxygen-containing gas for combustion to the high-temperature hearth is connected above the discharge path of the slag, a slag flow path from the high-temperature hearth to the discharge path An exothermic agent supply furnace for blowing reduced metal powder with an oxygen-containing gas at a portion located below the tuyere is provided, and the supply of the reduced metal powder supply device and the oxygen-containing gas pressurized supply device, which can be switched between supply stops, is performed using the exothermic agent The effect is as follows, since it is connected to the supply path.

(Operation)

Reduced metal powders such as Fe, Al, and Mg are supplied to the slag flow path from the high-temperature When blown with oxygen-containing gas, such as air or oxygen-enriched air, a large amount of heat is instantaneously generated due to the rapid oxidation of the reduced metal powder, and the slag that has become highly viscous or consolidated due to low temperature is melted. It is discharged smoothly.

Therefore, the state of slag is monitored automatically or artificially,
If the slag defect is predicted or detected, the reduced metal powder supply device and the oxygen-containing gas pressurized supply device can be automatically or artificially supplied to prevent the slag defect and eliminate the slag defect. If this is the case, the reduced metal powder supply device and the oxygen-containing gas pressurized supply device can be automatically or artificially stopped to prevent an unnecessary increase in cost due to unnecessary consumption of reduced metal powder and power.

In addition, the operation of the reduced metal powder supply device and the oxygen-containing gas pressurized supply device can be performed automatically or artificially in a safe place, and the work for eliminating defective slag can be performed safely.

Furthermore, since the reduced metal powder is blown with the oxygen-containing gas, the reduced metal powder and the oxygen-containing gas can be reliably supplied even to a narrow gap such as coke in the high-temperature furnace floor. However, even if the viscosity is increased or consolidation occurs, it is possible to easily and quickly eliminate defective slag.

〔The invention's effect〕

As a result, safety, workability,
It has become possible to provide a high-temperature hearth-type waste melting furnace that is excellent in economy.

〔Example〕

 Next, an embodiment is shown in FIG. 1 and FIG.

A hopper (2) for charging industrial waste and carbon-based combustibles is connected to the solid-state furnace (1) via a double damper (3), and the furnace is heated by the carbon-based combustibles from the hopper (2). A high temperature hearth (A) is formed at a lower portion, and a packed layer (B) of industrial waste is formed at an upper portion of the high temperature hearth (A). The tuyere (5) for supplying the combustion air from the blower (4) to the high-temperature hearth (A) is arranged so that its outlet is located below the upper surface of the high-temperature hearth (A) and in the furnace lower part circumferential direction. And an ignition burner (7).

The upper part of the furnace (1) is used as a flue gas rising passage (8),
A tuyere (9) for supplying air from the blower (4) for post-combustion is connected to a lower portion of the ascending flow path (8), and a flue gas exhaust passage (11) connected to the ascending flow path (8). ) Is provided with a cyclone (10) for dust collection.

A heat exchanger (13) for preheating air from the blower (4) to about 500 ° C with flue gas is provided in the exhaust path (11), and the high-temperature hearth (A) is configured to be about 1400 to 1600 ° C. It is.

A discharge path (12) for molten waste is connected to the furnace bottom so that industrial waste slag melted in the high temperature hearth (A) can be collected. The pressure inside the furnace is adjusted by the damper (14) in the exhaust passage (11) so that about 10 to 20% of the flue gas flows out of the exhaust passage (12), so that the slag discharge is smooth by the heat retention by the flue gas. Driven by

The exothermic agent supply path (15) is connected to the lower part of the furnace with the outlet near the inlet of the discharge path (12) and closer to the bottom of the furnace, and consists of a hopper (16a) and a rotary feeder (16b) A reduced metal powder supply device (16) and an oxygen-containing gas pressurized supply device (17) including a compressor, a blower, a cylinder and the like are connected to a heating agent supply path (15).

A sensor (S) for detecting the temperature of the discharge path (12) is provided, and based on information from the sensor (S), the reduced metal powder is blown into the furnace with the oxygen-containing gas only when the detected temperature is equal to or lower than the set temperature. A controller (18) for automatically operating a main switch and a valve of the rotary feeder (16b) and the oxygen-containing gas pressurized supply device (17) is provided.

The reduced metal powder generates a large amount of heat by rapid oxidation of Fe, Al, Mg, Mn, and others, and is used alone or in combination of two or more.

 The oxygen-containing gas is air, oxygen-enriched air, oxygen, or the like.

The mixing ratio of the reduced metal powder and the oxygen-containing gas is appropriately adjusted so that the total amount of the reduced metal powder is supplied with oxygen that is equal to or more than the theoretical oxygen amount required for oxidation, and preferably about 1.2 times as much as that of the rotary feeder (16b). And the flow rate of the oxygen-containing gas pressurized supply device (17). If the supply amount of the oxygen-containing gas is excessive, the temperature may be lowered. Therefore, it is preferable to set the supply amount of oxygen to about 1.5 times or less the theoretical oxygen amount.

The hopper (16a) has a closed structure, is filled with an inert gas from the cylinder (16c), and is configured to prevent oxidation of the reduced metal powder.

In short, if the slag becomes viscous or solidified due to low temperature near the entrance of the discharge path (12) where the temperature tends to decrease, the detection temperature of the sensor (S) decreases and the controller (18) automatically reduces it. A mixture of the metal powder and the oxygen-containing gas is blown into the vicinity of the inlet of the discharge path (12), and a large amount of heat is given to the vicinity of the inlet of the discharge path (12) by the rapid oxidation of the reduced metal powder, thereby increasing the viscosity. The slag that has been solidified is melted, and good slag is reliably maintained.

Also, MgO, MnO, and FeO are mixed into the slag by using Mg, Mn, and Fe as the reduced metal powder to improve the fluidity of the slag, or in the slag by using Fe as the reduced metal powder. The structure is such that Ni, Cr and the like can be fixed to an alloy such as Fe-Ni and Fe-Cr.

When the slag is good and the detection temperature of the sensor (S) is high, the supply of the reduced metal powder and the oxygen-containing gas is controlled by the controller (1).
The system is automatically stopped by 8) to eliminate wasteful consumption of reduced metal powder and oxygen and wasteful power consumption of compressors and blowers, thereby enabling economical operation.

(Another embodiment)

 Next, another embodiment will be described.

The industrial waste input from the hopper (2) is, for example, various industrial wastes such as sewage sludge, tire waste, municipal garbage incineration ash, waste catalyst or intermediate products thereof. Briquettes, such as coke, anthracite,
Such as graphite electrode waste.

The blowing position of the heating agent supply passage (15) can be changed appropriately,
Further, a plurality of exothermic agent supply paths (15) may be provided side by side in the vertical direction and / or the circumferential direction of the furnace. In short, the flow path of the slag from the high-temperature hearth (A) to the discharge path (12) may be reduced. One or more exothermic agent supply passages (15) for blowing reduced metal powder with an oxygen-containing gas may be provided in a portion located below the tuyere (5). Heating agent supply path (15)
May be inserted from the discharge channel (12).

The reduced metal powder supply device (16) can be appropriately selected from known powder supply devices.
7) can also be appropriately selected from known pressurizing and supplying devices such as air and oxygen, and any device is not particularly limited in specific configuration.

A specific configuration can be changed as appropriate so that the suction of the reduced metal powder can be automatically performed. For example, the configurations of the following items (a) to (c) can be used.

(B) Instead of a temperature detection sensor (S), a radiation thermometer for detecting the slag temperature of the discharge path (12) is provided,
Known appropriate means can be used, such as providing an image analysis device for determining the quality of the slag flow state of the discharge path (12), and these are collectively referred to as slag flow state detection means (S).

(B) A specific configuration for interrupting the blowing of the reduced metal powder through the exothermic agent supply passage (15) can be appropriately selected from known powder air flow transport interrupting means, and these are collectively referred to as supply interrupting means.

(C) The program of the controller (18) for injecting the reduced metal powder only when the slag flow state is deteriorated can be appropriately selected. For example, if the slag flow state is improved, the injection of the reduced metal powder is stopped immediately, or a certain amount after the improvement. After a lapse of time, the blowing of the reduced metal powder may be stopped.

The injection of the reduced metal powder may be performed manually, in which case the amount and temperature of the combustion exhaust gas and slag in the discharge path (12) are measured with an instrument or by visual measurement, and the measurement value is set. In the following cases, the blowing of the reduced metal powder may be continued for an appropriate time by artificial judgment.

The adjustment of the heating temperature by blowing the reduced metal powder is performed by adjusting the amount of the reduced metal powder and the oxygen concentration of the oxygen-containing gas.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the structure shown in the attached drawings.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is an overall schematic view, and FIG. 2 is a main part view. (5) ... tuyere, (11) ... exhaust path, (12) ... discharge path, (15) ... heating agent supply path, (16) ... reduced metal powder supply apparatus, (17) ... Oxygen-containing gas pressurized supply device, (18)
... Controller, (A) ... High-temperature hearth, (S) ... Slag flow state detection means.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuo Horie 2-1-1, Toyosu, Koto-ku, Tokyo Ishikawa Shima-Harima Heavy Industries Co., Ltd. Tokyo 1st Plant (72) Inventor Shoji Furuya 2-Toyosu, Koto-ku, Tokyo No. 1-1 Ishikawa Shima-Harima Heavy Industries Co., Ltd. Tokyo No. 1 Factory (72) Inventor Shin Shimizu 3-2-1-16 Toyosu Koto-ku, Tokyo Ishikawa Shima-Harima Heavy Industries Co., Ltd. Toyosu General Office

Claims (3)

(57) [Claims] 1. A discharge path (12) for industrial waste slag melted in a high-temperature hearth (A) formed of a carbon-based combustible material is connected to a furnace bottom, and an exhaust path (11) for combustion exhaust gas is connected to the high-temperature high-temperature furnace. Industrial waste connected above the hearth (A) and having a tuyere (5) for supplying the oxygen-containing gas for combustion to the high-temperature hearth (A) above the slag discharge path (12) In a melting furnace, reduced metal powder is blown by an oxygen-containing gas into a portion of the slag flow path from the high temperature hearth (A) to the discharge path (12) located below the tuyere (5). An industry in which an exothermic agent supply path (15) is provided, and a reduced metal powder supply apparatus (16) and an oxygen-containing gas pressurized supply apparatus (17) that can be switched to supply stop are connected to the exothermic agent supply path (15). Waste melting furnace. 2. The industrial waste melting furnace according to claim 1, wherein an outlet of the heating agent supply passage (15) is directed to a portion near an inlet of the discharge passage (12) and near a bottom of the furnace. 3. A means (S) for detecting a slag flow state of said discharge passage (12), and based on information from said slag flow state detection means (S), reducing metal powder only when the slag flow state deteriorates. The industrial waste melting furnace according to claim 1 or 2, further comprising a controller (18) for automatically operating the supply intermittent means of the exothermic agent supply passage (15) so as to blow air.