JPS5849609B2 - Blast furnace firing method - Google Patents

Description

[Detailed description of the invention] This invention relates to a method for tapping iron in a blast furnace,
We propose a new method for tapping iron that can ensure a stable outflow of hot metal and fermentation slag, and can continue tapping for a long period of time.

Conventionally, for a planned tapping operation, it has been necessary to ensure a tap hole depth of an appropriate length.

Conventionally, in order to ensure the depth of the tap hole, it was necessary to control the amount of filled refractory material (called matudo) filled into the hole with a matudo gun, or to devise the method of drilling the hole with a drilling machine. Efforts were made to make adjustments through various means and to enable smooth tapping.

Moreover, the wood that originally forms the holes obtained by opening the holes has only a low strength that is naturally fired by the heat in the furnace, and no matter how strict the quality control of the wood is, it often During the tapping operation, it wore out abnormally early, making the tapping operation difficult.

In short, the roughness of tapping is a number 1, both inside and outside the furnace.
1500℃ between two areas with a pressure difference of 1f
It is thought that the method of releasing very high temperature pig iron slag all at once into the atmosphere without any pressure reduction or pressure equalization operations is unreasonable.

In this sense, even if it is possible to drill a smooth, nearly perfect round tap hole according to the dimensions with the drill of a hole-drilling machine, as shown in Figure 1, any pattern of early stop, standard, or slag delay will result. Even in this case, the inner surface of the tap hole is eroded by the hot iron and slag, leading to an enlargement of the hole diameter and an increase in the flow velocity, which progresses at an accelerated pace.

As a result, there is a tendency for the amount of slag flowing out from the tap hole to be larger than the amount of inflow of pig iron slag that collects in the tap hole part of the hearth, and eventually, this is accompanied by the phenomenon of blowing out of the gas in the furnace. ,
The taphole blockage has come to an end.

In contrast, in the past, in addition to improving the quality of mats as described above, (
b) A method of controlling the outflow rate of pig iron and slag by connecting a sump to the tap hole, adjusting the internal pressure in the sump, and specifying the tap area (Utility Model Publication No. 49-10490)
No.), 0) A method of constructing a block outside the tap hole to increase the length of the tap hole and substantially increasing the depth of the tap hole (Utility Model Publication No. 47-8409).

In the case of the former, the repair of the sump becomes long and has a negative impact on furnace operation, and in the latter case, it is necessary to lengthen the length of the taphole opening machine and use a drill rod as long as 6 m. The situation was such that it was impossible to drill holes.

This invention is a method of tapping operation developed with the aim of overcoming the drawbacks of the prior art, and is a method that enables tapping and slag for a long time without increasing the burden on the taphole opening. be.

The gist of this is that after opening the taphole of the blast furnace,
A refractory cylindrical removable nozzle with a hole in the center is pressed into contact with the taphole, and tapping and slag are performed through the nozzle hole communicating with the hole. The slag stopper is closed by removing the pressed nozzle from the taphole and filling the taphole with mud.

The details of the configuration will be explained below.

2 to 4 of the drawings show a pivot support device for a nozzle used in the method of this invention.

Reference numeral 1 designates a nozzle consisting of a cylindrical refractory material with a through hole 2 in the center surrounded by a water-cooled jacket Ha, which is rotatably supported by a swing support device and installed at the tap hole as needed. It is used by being crimped onto the end face (inlet) of No. 3 or detached from it.

The timing for attaching and detaching the nozzle 1 from the taphole 3 is such that when the taphole 3 is drilled by the hole-drilling machine, the nozzle 1 is rotated from the retracted position and its tip 1a is pressed into contact with the taphole.
The hole path of the tap hole drilled by a drill is communicated with the nozzle passage hole 2, and concrete tapping and slag are performed from the free end 1b of the nozzle.

On the other hand, at the final stage of tapping and slag, the nozzle 1 is rotated back to its original retracted position, and the mud gun is operated to fill the mouth of the tap hole 3 with mud.
block itself.

In short, in the method of this invention, the work of opening and closing the hole is performed on the tap hole 3 itself, and the hot metal and molten slag during tapping are spouted into the tap flute 4 through the nozzle attached to the tap hole. This is the method I used.

Note that the nozzle 1 that is attached to and detached from the taphole 3 is as shown in the figure.
It is supported by a suspension arm 6 fixed on the swivel base 5, and rotates in synchronization with the rotation of the swivel base 5.

Further, the tilting for tightly pressing the nozzle tip 1a against the tap hole 3 is performed by the linked operation of the cylinder γ installed between the swivel table 5 and the suspension arm 6 and the tilting lever 8 of the link mechanism.

When tapping is performed through the nozzle passage hole 2 as described above, a significant pressure drop occurs, resulting in a state where the pressure is reduced by 1 to 2 KicrA compared to the normal state, and the hot iron and slag can be discharged quietly.

As a result, the load on the inner surface of the taphole (wall pressure applied to the taphole) is reduced, reducing its wear and tear, leading to an enlargement of the inner diameter of the taphole at the end of the tap, an increase in the amount of outflow, and the ejection of gas. You can slow down the process.

Therefore, as shown in FIG. 5, compared to the conventional example 0), the method (hole) of the present invention significantly increases the continuous tapping time, which in turn greatly contributes to saving labor in front of the furnace.

In addition, this tapping operation by attaching and detaching the nozzle 1 can be done by arbitrarily changing the depth of the taphole in response to changes in furnace operating conditions, for example by selecting the nozzle diameter and hole length suitable for the hot air pressure. The same effect (adjustment of pressure loss) as in the above can be obtained, and stable blast furnace operation can be obtained.

In addition, by reducing the above-mentioned load, the quality requirements for the mat can be relaxed, and by reducing the number of times of tapping, the amount of mat used and operation support materials such as driving metal rods can be reduced, which is economically advantageous. It is.

[Brief explanation of the drawing]

Figure 1 of the drawings is a line diagram of various tapping/slag patterns, Figure 2
The figure is a plan view of the nozzle rotation support device, FIG. 3 is a front view of the nozzle rotation support device, FIG. 4 is a side view of the nozzle rotation support device, and FIG. 5 is a conventional example of tapping/slag patterns and an example of the present invention. It is a line diagram which compares and shows. 1... Nozzle, 1a... Tip of the nozzle, 1b... Free end of the nozzle, 2... Through hole of the nozzle, 3... - Tap hole, 4... Tap hole, 5... Swivel table, 6... Suspension arm, 1... Cylinder, 8... ...Tilt lever.

Claims (1)

[Claims] 1 After opening the taphole of a blast furnace, a refractory cylindrical removable nozzle with a through hole in the center is pressed into contact with the taphole, and the tap iron and slag are communicated with the hole. The method is characterized in that the nozzle, which has been pressed under pressure, is removed from the taphole, and the nozzle is filled with mud into the taphole. Blast furnace tapping method.