JPS6224484B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an apparatus for controlling reactions in a converter during operation of a converter.

Prior Art The purpose of converter operation is to reduce the carbon contained in the molten metal using oxygen supplied during converter blowing, and to turn the slag-forming agent introduced into the furnace into sludge, thereby separating the generated molten slag and The purpose is to cause dephosphorization, desulfurization, etc. to occur through reaction with the molten metal.

In this case, the slagging state of the slag is a major factor that determines the operational results.If the slag sludge progresses excessively, it will promote the forming state of the slag and eventually lead to an abnormal reaction in which slag overflows outside the furnace, that is, slopping. This causes various problems such as reduced work efficiency, reduced iron yield, deterioration of the working environment, and damage to equipment.

On the other hand, in the case of poor slag formation, the dephosphorization effect and the like deteriorate, making it impossible to obtain steel of desired quality.

Quicklime is charged after the start of blowing to form slag, but in this case limestone, dolomite, or fluorite is also usually added as a solvent. Since then, in order to adjust the conditions inside the furnace, iron ore as a coolant or the above-mentioned solvent has been added in portions. In general, these auxiliary materials were required to be in the form of granules so as not to scatter.

On the other hand, a method has been disclosed in which a powder material, which is cheaper than a granular material, is added to pressurized air through a tapping port when the slag and metal are in an emulsion state after the start of blowing. (Sho 54-107414).

This law also stipulates the timing of blowing, which is defined as the time when the amount of slag on the surface of the steel bath increases after the start of blowing, that is, about 10 minutes after the start of blowing. Therefore, there was no attempt to control the situation inside the furnace throughout the entire blowing period.

OBJECT OF THE INVENTION The object of the present invention is to provide a device for injecting powder for reactor reaction control together with a carrier gas through a through hole provided in a side wall of a converter, the probe of the device detecting light in the furnace in an injection nozzle. The purpose of the present invention is to provide a device that is equipped with a control powder and quickly injects control powder at the required time according to the obtained furnace condition.

Structure and operation of the invention The structure of the present invention is an in-furnace reaction control device that injects powder for in-furnace reaction control into the furnace together with a carrier gas from a through hole provided in the side wall of the converter body, the in-furnace reaction control device comprising: A probe of a photodetection device equipped with a purge device for cleaning an observation window at the tip is installed inside the blowing nozzle, and in response to a signal for detecting the condition inside the furnace from the detection device,
This is a reaction control device in a converter furnace, characterized in that it is configured to inject powder for reaction control.

This will be explained in detail using drawings.

FIG. 1 is an explanatory diagram showing the entire structure of this device.

In FIG. 1, a probe 62, which is a component of a photodetector, is installed inside a blowing nozzle 6, which is a part of a blowing device, and a light guide 61 shown in FIG. 2 is built into the probe, and its tip Observation window 63
is attached by a chip 64. A photoelectric conversion element 1 is connected to the rear end of the light guide via an exchange connector 9.
0 is connected and the blowing device 6 faces the through hole provided in the side wall of the converter body, the light inside the furnace that enters through the observation window is photoelectrically converted and the signal is sent to the calculation device 11.
The calculated furnace condition signal is sent to the furnace condition display device 12, where the furnace condition is displayed as an image.

In the present invention, the photodetection device refers to a series of devices from the probe 62 containing the light guide 61 to the furnace status display device 12.

The in-furnace situation signal, which is the output after the calculation of the calculation device 11, is further sent to the blowing control device 13 which controls the blowing device.
sent to.

In the present invention, the blowing device includes a receiving tank 72 for powder for reaction control, and a powder feeding tank 7 that can be sealed so that it is replenished from the receiving tank and pressurized with inert gas.
0, a carrier gas piping system 50 necessary for powder transportation, and a blowing nozzle 6 illustrated in FIG.
It is a device equipped with

The above-mentioned blowing control device causes gas from the inert gas source 30 to flow into the powder feeding tank 70 for reaction control powder, pressurizes it, adjusts the opening degree of the outlet valve 71 of the powder feeding tank, and further controls the powder feeding tank 70. The flow rate adjustment device 53 of the carrier gas piping system 50 is controlled to control the amount of reaction control powder and carrier gas blown into the system.

The aforementioned light guide is a conductor, such as a quartz-based optical fiber, that transmits radiation emitted from a high-temperature object with low loss. The probe 62 is placed in a high temperature and dusty environment during observation inside the reactor, so as an example, as shown in FIG. 2, the probe 62 is
It has a double tube structure with a chip 64 attached to the tip of the probe, and in the gap 65 between the light guide and the probe, there is a purge gas which has the function of cleaning the observation window 63 attached to the tip of the light guide and cooling the light guide. Entrance 66
and an outlet 67, forming a purge device for cleaning the observation window, and purging with the purge gas of the piping system 40.

Further, by configuring the through hole so that the blowing nozzle 6 can be removed, it is possible to utilize a tapping hole provided in the side wall of the converter. Furthermore, except for the bottom part, which is always immersed in molten metal during blowing, any part of the furnace wall that is not immersed in molten metal when the converter is tilted during hot metal charging or tapping can be selected.

Regarding powder for reaction control, as mentioned above, considering that the state of slag in the converter has extremely important meaning in operation, it is important to use the information obtained by the photodetector, for example, based on the amount of slag. If slag tends to drop below the standard level, it is preferable to inject oxidizers such as iron sand powder, sintered ore powder, scale powder, or ferromanganese ore powder, and if slag tends to become excessive, use coke powder or coal powder. Injection of a reducing agent containing a carbon source such as is preferred.

In the above-mentioned Figure 1, it is depicted as if only one type of powder is being blown, but this is only for illustrative purposes, and it is assumed that at least two types of powder, ring agent powder and oxidizing agent powder, are being blown. It is desirable to install the equipment so that it can be fully accommodated.

However, as a result of various studies regarding the powder particle size,
It was concluded that 5 mm or less is suitable from the reactivity inside the furnace, the efficiency of air flow transport, etc.

The carrier gas is a gas that does not react with the aforementioned control powder, does not easily react with the contents of the furnace when blown into the furnace, and does not affect the composition of the target steel. Preferably, an inert gas such as CO ₂ , Ar, or N ₂ is used.

The carrier gas not only pneumatically transports the control powder, but also provides cooling protection for the probe 62 by being introduced from the carrier gas inlet 68 and passing through the gap 69 surrounding the outer wall of the probe 62, as shown in FIG. Since it plays a useful role, it is preferable to run it all the time while observing the furnace condition.

By the way, by blowing the carrier gas and purge gas (hereinafter collectively referred to as cooling gas) and blowing the powder, the blow nozzle 6
The slag or the powder may adhere and grow on the tip of the converter or the through-hole near the inner wall of the converter, causing the through-hole to become clogged. In order to prevent this adhesion growth, in the experience of the present inventors, it was effective to add O ₂ to the purge gas for cleaning the observation window 63. In other words, after cooling the probe while purging the front of the observation window 63, this purge gas is burned at the tip of the blowing nozzle 6 to prevent slag and powder from adhering to the O ₂ If the amount added is about 30% of the total amount of cooling gas, the light guide 6
The above function could be achieved without damaging the observation window 63 or the observation window 63.

FIGS. 3 and 4 are diagrams showing other embodiments that effectively prevent the adhesion growth. In this embodiment, as shown in FIG. 4, a triple-pipe structure is used in which a gap 691 through which purge gas flows is formed further outside a gap 69 through which powder is blown in together with a carrier gas. Thus, the purge gas, which is the inert gas added with O ₂ supplied from the O ₂ gas piping system 55, is supplied through the gas inlet 692 and is ejected from the tip opening 693. In FIG. 3, reference numeral 56 denotes a ratio setting device, which adjusts the opening degree of the flow rate regulating valves 57 and 58 so that O ₂ is added at a predetermined ratio to the flow rate of the inert gas. Thus, in this embodiment, from the tip opening 693 of the outermost cavity 691 of the blowing nozzle 6,
Purge gas added with O ₂ is ejected and burned at its tip, which effectively prevents slag and powder from adhering to the light guide 61 and observation window 63.
It did not cause any damage at all. In experiments conducted by the present inventors, it was found that if the amount added is about 30 to 45% of the total amount of cooling gas (gas passing through the gaps 65, 69, and 691), it would damage the converter side wall bricks. It was possible to prevent the through hole from clogging without causing any damage. Of course
O ₂ should be added only when slag or powder adhesion occurs, or a small amount is usually added to prevent adhesion, and the amount added should be increased when adhesion occurs. It is also possible to perform control, and it is only necessary to select and employ it as appropriate.

Example 1 A 170t top-bottom blowing converter was used to produce low-coal Al-killed steel, and the equipment of the present invention was installed and operated. One through hole was provided at a vertical distance of 2.5 m below the furnace mouth, and the apparatus of the present invention was installed. 100Nm ³ /H of CO ₂ gas was flowed for cleaning the observation window and cooling the probe.
Furthermore, the carrier gas is supplied from the gas inlet 68.
A flow rate of 120Nm ³ /H was applied.

Signals indicating possible slopping were obtained from the detection device at 12 and 16 minutes after the start of blowing.
The carrier gas control device was immediately activated, and the carrier gas flow rate was increased to 600Nm ³ /H, and the coal powder of 3 mm or less stored in the powder feeding tank 70 was removed.
Kg and 140 Kg were injected with carrier gas at a maximum charge rate of 200 Kg/min to prevent slopping. Note that after the trend of slopping control was confirmed and the charging of coal powder was completed, the carrier gas flow rate was restored to 120 Nm ³ /H.

Example 2 When manufacturing low carbon Al killed steel in a 170t top-bottom blowing converter, the apparatus of the present invention shown in FIGS. 3 and 4 was installed and operated. The through hole is placed at a vertical distance from the furnace mouth.
One device was installed at a position 2.5 m below, and the device of the present invention was installed. For cleaning the observation window and cooling the probe, 100 Nm ³ /H of CO ₂ gas was flowed through the gas inlet 66 and 120 Nm ³ /H of carrier gas was flowed through the gas inlet 68 . Further, in order to prevent clogging of the through hole, 200 Nm ³ /H of O ₂ gas was added to 100 Nm ³ /H of CO ₂ gas and flowed through the gas inlet 692.

At 11 minutes and 17 minutes after the start of blowing, signals indicating the possibility of slopping were obtained from the detection device, and the carrier gas control device was immediately activated, the carrier gas flow rate was increased to 600Nm ^{3 /H, and the flow rate was increased to 600Nm 3} /H. It was stored. Maximum charge rate of 130Kg and 170Kg of coal powder less than 3mm is 200Kg/
It was blown in with the carrier gas at min, and slopping was prevented.

Furthermore, after the trend of slopping control is confirmed and the charging of coal powder is completed, the carrier gas flow rate is
It was restored to 120Nm ³ /H.

In addition, after the blowing was completed, the through holes were observed and found that they were the same as before the blowing, with no slag or powder adhering to them, and no tendency to blockage.

Effects of the Invention With the device of the present invention, the information obtained from the photodetection device can be quickly connected to powder charge operation, and the carrier gas has a cooling protection effect on the detection device, allowing stable blowing. The practical effects are huge.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the entire structure of this device, Fig. 2 is a partial sectional view showing one example of the structure of the nozzle of the blowing device, and Fig. 3 is an explanatory diagram showing the entire structure of another embodiment of this device. , FIG. 4 shows one of the nozzle structures according to FIG.
It is a partial sectional view showing an example. 6...Blow nozzle, 9...Replacement connector, 10
...Photoelectric conversion element, 11... Arithmetic device, 12...
Furnace condition display device, 13...Blowing control device,
30... Inert gas source, 40... Purge gas piping system, 50... Carrier gas piping system, 51... Stop valve, 52... Pressure reducing valve, 53... Flow rate adjustment device, 5
4...stop valve, 55... _O2 gas piping system, 56...
Ratio setter, 57, 58...Flow rate adjustment valve, 61...
...Light guide, 62...Probe, 63...Observation window,
64...Tip, 65...Gap, 66...Purge gas inlet, 67...Purge gas outlet, 68...Carrier gas outlet, 69...Gap, 691...Gap, 692...Gas inlet, 693...Tip opening , 70...Powder feeding tank, 71...Outlet valve, 72
...Reception tank.

Claims (1)

[Claims] 1 An in-furnace reaction control device that injects powder for in-furnace reaction control into the furnace together with a carrier gas through a through-hole provided in the side wall of the converter body, and has an observation window cleaning at the tip in the blowing nozzle of the blowing device. 1. A converter reactor reaction control device, characterized in that the probe of a photodetection device equipped with a purge device is installed inside the converter furnace, and powder for reaction control is injected in response to a furnace condition detection signal from the detection device. .