JPS6335712A - Metallurgical furnace having plural tap holes in steps - Google Patents

Abstract

PURPOSE:To enable efficient and continuous operation of a furnace by piercing prescribed tap holes in the side wall of the furnace above and below a starting material charge hole pierced in the side wall so as to freely regulate the level of a metal bath. CONSTITUTION:A tap hole 7 is pierced in the side wall of a furnace 1 above a starting material charge hole 8 pierced in the side wall so that molten metal 5 is tapped during ordinary operation. Plural tap holes 7 may be pierced in steps. A tap hole 9 is further pierced in the side wall below the hole 8 so that the molten metal 5 is tapped before the repair of the furnace or in case of emergency. Plural tap holes 9 may be pierced in steps. The starting material charge hole 8 is prevented from being blocked up by the molten metal 5 penetrating into the hole 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a metallurgical furnace used in iron making, steel making, etc.

[Conventional technology]

Recently, the smelting reduction smelting method has been attracting attention as a steelmaking technology to replace the blast furnace/converter method. The smelting reduction furnace used in this method is not limited by the raw materials used, and it is possible to prepare molten iron alloys with a smaller-scale installation of 6iN, and to effectively utilize the heat generated during the smelting reaction. It was developed for the purpose of recovering the waste.

There are two types of such melting reduction furnaces: those with a tilting hearth (Japanese Patent Application Laid-Open No. 129617/1983, etc.) and those with a fixed hearth (Japanese Patent Laid-Open No. 71613/1989, etc.). being classified.

In a smelting reduction furnace with a tilting hearth, it is difficult to seal the furnace body, which reduces the exhaust gas recovery rate.
There is no effective heat recovery.

Another disadvantage is that the mechanism for supporting and tilting the furnace body is complex.

On the other hand, a smelting reduction furnace with a fixed hearth is seen as promising as a solution to these drawbacks. FIG. 2 shows an example of this smelting reduction furnace with a fixed hearth.

In this furnace, a lance 2 is inserted into the furnace body 1 from vertically above and a lance 3 is inserted from diagonally above or from the side. Gas such as oxygen gas and/or powder such as ore 1 coal is blown into the furnace from these lances 2.3. Furthermore, a lump charging device 4 is provided in the upper part of the furnace body 1, and lumps such as ore, molded products thereof, and lump coal are poured into the lump charging device 4.

At the beginning of smelting, a required amount of metal bath 5 is formed in advance, and as a result of the reduction reaction of the ore with the carbon material suspended in the slag layer 6 above it, the metal bath 5 reacts with the progress of smelting. The amount will be increased accordingly. Therefore, when the amount of metal bath 5 increases, the metal bath 5 is taken out from the tapping lower.This tapping lower is for tapping molten metal, but by setting the position above the metal bath 5, the metal bath 5 is removed. It also has the role of maintaining the height at a predetermined value.

[Problem that the invention seeks to solve]

As described above, lumps such as ore, molded products thereof, and lump carbonaceous materials are fed from the lumps charging device 4 . However,
In order to improve the reaction efficiency or to use the raw materials as they are, it is desirable to design the reactor so that it is possible to input raw materials in the form of small particles or powder. However, when trying to feed raw materials such as small particles or powder from the lump material charging device 4, a large proportion of the powdery raw materials are scattered due to the exhaust gas rising through the slag layer 6, etc. The addition efficiency will be low.

Therefore, in order to prevent the loss of material due to this scattering, a raw material inlet is separately provided at a position below the tapping lower on the side wall of the furnace body, and the raw material is directly poured into the metal bath 5 in the form of small particles.

It is conceivable to charge raw materials such as powder by blowing gas or the like. However, when charging raw materials in this way, since the raw materials are blown sideways, there is less separation from the carrier gas (this increases the addition efficiency, but the boiling effect on the molten metal is small due to the short distance from the scene). Therefore, it is necessary to provide this raw material inlet in the side wall at a certain vertical distance from the bottom of the furnace.

In this way, when providing an inlet for raw materials such as small particles or powder on the side wall, a certain amount of blowing depth is required to improve the addition efficiency, and the slag is generated at the same time as the molten metal and reaches the slag-metal interface. Because it is necessary to discharge a certain slag at the same rate as the molten metal, etc., the level of the metal bath 5 cannot be lowered below the tapping lower. This restriction means that when the smelting reduction furnace is under normal operating conditions, Does not cause any particular problems. However, when smelting operations are stopped during furnace repairs or emergencies, small particles from the raw material input port,
If the supply of the $51 raw material or gas blowing is stopped, the blowing nozzle etc. is likely to become clogged because the raw material inlet is located below the level of the metal bath 5.

Furthermore, if the blowing nozzle is damaged, a large amount of molten metal may flow out from the nozzle.

Because of these problems in actual operation, the method of injecting raw materials below the bath surface in a fixed hearth type furnace has not been adopted as a practical method.

In addition, in order to ensure the distance between the raw material inlet and the tapping lower, the distance from the bottom of the furnace to the tapping lower becomes large. Seven results, during repairs and %1. At times, it is necessary to store a large amount of metal bath 5 in the furnace. Therefore, the high heat of the metal bath 5 remaining in the furnace during non-operation is dissipated, which is disadvantageous from a thermoeconomic standpoint.

The problems described below are not simply problems specific to melting reduction furnaces, but are common to furnaces in which the outlet is located above the raw material inlet.

Therefore, an object of the present invention is to provide a metallurgical furnace in which the level of the metal bath can be lowered below the raw material input port as necessary by separately providing a tap port for temporarily taking out molten metal.

[Means and operations for solving the problems] In order to achieve the purpose, the metallurgical furnace of the present invention has one or more metallurgical furnaces through which molten metal is taken out during normal operation above the raw material charging port provided on the side wall of the furnace body. The present invention is characterized in that a stepped tap water outlet is provided, and a single or multiple step tap L1 for temporarily taking out the rocky area is provided below the raw material charging port.

That is, the tap at the top is used during normal operations, and the tap at the bottom is used when repairing the furnace body, during emergencies, etc. By discharging the metal bath in the furnace from this lower outlet, the level of the metal bath can be adjusted as desired.

〔Example〕

Hereinafter, features of the present invention will be specifically explained with reference to embodiments shown in the drawings.

FIG. 1 shows an example in which the present invention is applied to a smelting reduction furnace having a fixed hearth. In FIG. 1, the same members and the like as those in FIG. 2 are indicated by the same reference numerals, and their explanations are omitted.

On the side wall of the furnace body 1, a raw material inlet 8 for small granular, powdery raw materials, etc. is provided below the tapping lower. This raw material input port 8
Further below, a second tap 9 is arranged, and molten metal is temporarily taken out through this tap 9. In addition, in FIG. 1, in order to simplify the drawing, only one hot water lower is shown.

9 is shown, but a plurality of these tapping lowers 9 can be arranged in the circumferential direction of the furnace body. Further, the relationship between the plurality of tapping lowers or tap openings 9 may be either on the same circumference or arranged with a difference in top and bottom.

In this way, by providing the tap 9 for temporary tapping below the raw material inlet 8, it becomes possible to bring the level of the metal bath 5 in the furnace below the raw material inlet 8. Therefore, for example, when repairing the inside of the furnace, even if gas injection from the raw material inlet 8 is stopped, the nozzle will not be clogged due to molten metal entering the gas injection nozzle.

In FIG. 1, the tap 9 for temporary tapping is provided at the lower end of the side wall of the furnace body 1. In this case, the level of the metal bath 5 can be adjusted to an appropriate height by attaching an appropriate scene detector to the furnace body 1 and controlling the opening and closing of the tap 9 based on the signal from the scene detector. becomes.

The tap hole 9 for temporary tap tap should be installed in a position that allows the minimum amount of metal bath 5 required to continue the smelting reduction process to remain in the furnace, without being restricted by FIG. 1. Alternatively, a tap 9 may be provided.

In this way, the metal bath 5 in the furnace can be lowered to 8 or less for raw energy 1 input. Therefore, in the case of emergency shutdown due to furnace body repairs or operational troubles, there will be no adverse effect on the raw material input port 8, and the tapping of hot water through the tap port 9 will not cause any damage to the inside of the furnace. Since the amount of remaining metal bath 5 can be reduced to the minimum required value, it is also possible to suppress the amount of heat wasted from metal bath 5 during non-operation.

In the above explanation, a melting reduction furnace is taken as an example.

However, the present invention is not limited to this, and can of course be applied to other furnaces in which the outlet is above the raw material input l (for example, scrap melting furnace 3 right coal gasification furnace, etc.). .

〔Effect of the invention〕

As explained above, in the present invention, tap ports are provided above and below the raw material inlet for directly charging raw materials such as small particles and powder into the metal bath. Therefore, the level of the metal bath can be freely changed to the A type both in normal and temporary situations, and for example, when repairing the furnace body, the raw material inlet is prevented from being clogged by intrusion of molten metal. In this way, according to the present invention, efficient continuous operation is possible.

[Brief explanation of the drawing]

FIG. 1 shows an example in which the present invention is applied to a fixed hearth type melting reduction furnace, and FIG. 2 shows a conventional fixed hearth type melting reduction furnace.

Claims (1)

[Claims] 1. A single or multiple outlet for taking out the molten metal during normal operation is provided above the raw material charging port provided on the side wall of the furnace body, and a single or multiple outlet for temporarily taking out the molten metal below the raw material charging port. A metallurgical furnace characterized by having a sprue.