JPS6232986Y2 - - Google Patents

Description

[Detailed explanation of the idea] (b) Industrial application fields The present invention relates to a drill hole for tapping.

(b) Conventional technology In recent years, with the advancement of steelmaking technology, blast furnaces have become larger, and the amount of iron tapped per day has come to exceed 10,000 tons.

It goes without saying that sophisticated operating technology is required to operate such a large blast furnace stably, but it is also extremely important how to stably extract the hot metal and slag produced within the furnace. This is a serious problem.

Therefore, various devices such as a tap hole drilling device for extracting hot metal slag are required to have high reliability. If a problem occurs with these devices,
Not only will it be impossible to maintain stable operations, but
This may lead to an unexpected major accident.

As shown in FIG. 5, the taphole drilling device includes a drill bit 1 having a bit 8 at the tip of a pipe 10 and a socket 9 at the rear, a screw rod 2 connected to the rear of the drill bit 1, and a drill hole drill 3. and a support mechanism 4 for these. In the figure, 7 indicates a furnace brick.

The drilling machine 3 is a device that applies rotation and impact motion to the bit 8 at the tip of the drill, and this movement is transmitted from the drilling machine 3 to the bit 8 via the screw rod 2 and the pipe 10.
It is transmitted to

The drill bit 1 and the screw rod 2 are shaped like hollow pipes, and are compressed to blow away chips drilled by the bit 8 from the refractory filled in the tap hole 5 and to cool the bit 8. The tap hole 5 is excavated while air is passed through and blown out from the air outlet 11 provided in the bit 8.

As the drilling progresses and the bits 8 reach the hot metal 6 in the furnace A, the tap hole 5 is completely opened and the hot metal 6 in the furnace A is taken out of the furnace through the tap hole 5. The drill bit 1 used here is damaged by melting due to the hot metal 6 passing through the tap hole 5 at the same time as the tap hole 5 is opened, so that the screw rod 2 is removed from the socket 9 at the rear end of the drill bit 1. Separate and discard.

This type of taphole drilling work is carried out 15 to 20 times a day, but if the taphole drilling equipment malfunctions and drilling is not possible when necessary, the daily production will be reduced by 10,000 yen.
In a ton blast furnace, molten products accumulate at a rate of 7 tons of hot metal and 2 tons of slag per minute, a total of 9 tons.

In other words, the reliability of the tap hole drilling device needs to be extremely high. In the conventional taphole drilling technology, when the taphole is opened, the bit 8 at the tip of the taper 1 breaks through the last wall and comes into contact with the hot metal 6 in the furnace A, and at the moment the bit 8 enters the pipe 10 of the taper 1. The hot metal 6 flows back into the pipe 10 of the cone 1, overcoming the pressure of the compressed air for cooling the bit 8 and blowing off chips. The backflowing hot metal 6 is not limited to the area of the drill bit 1, but may also reach the inside of the screw rod 2, and sometimes even the hole drilling machine 3. The backflowing hot metal 6 is cooled and solidified at that position, so that the screw rod 2 And the drilling machine 3 loses its function.

Such solidified pig iron could not be easily removed, and the parts had to be replaced within the limited time until the next tap hole was opened, resulting in loss of parts, time and labor, and threatening the stable operation and work of the blast furnace.

One way to solve this problem is to
Japanese Utility Model Publication No. 55-35304 discloses a technique in which a metal piece is inserted into the pipe 10 and the hot metal flowing backward is cooled and solidified by the metal piece, thereby stopping the backflow of the hot metal at the tip of the cone. has been done.

(c) Problems that the invention aims to solve However, with this technology, when the bit 8 at the tip of the drill bit 1 breaks through the last wall and comes into contact with the hot metal 6 in the furnace A, the drill melts and at the same time prevents this backflow. This has resulted in frequent troubles in which metal pieces used for heating have gotten into the furnace and the backflow prevention function has not been achieved. This is because the cross-sectional area of the pipe 10 and the air space between the metal pieces were expanded by changing the conical pipe 10 to a thin-walled pipe as part of cost reduction, and the backflow passage was expanded, and the internal pressure of the blast furnace This is due to the increase in

Therefore, with the backflow prevention drill hole disclosed in Publication of Utility Model Publication No. 55-35304, it is difficult to prevent hot metal from flowing back when the tap hole is opened, and the hot metal 6 that flows back does not stay within the range of the drill hole 1. The hot metal 6 that flows back into the screw rod 2 and sometimes even the inside of the hole puncher 3 cools and solidifies at that position, causing the screw rod 2 and the hole puncher 3 to lose their functions. There was a problem.

(d) Means for solving the problem The present invention was made in view of the above situation, and the present invention has been developed by installing a pipe 10 at the end of the screw rod 2.
A pipe 10 connected to the pipes 10 has a taper hole 8 at its tip, and a short small-diameter pipe 12 with a constricted portion 12A formed at the rear thereof is slidably inserted into the pipe 10. The gist of this paper is a tap hole drilling drill.

(e) Examples The present invention will be explained below based on the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention,
FIG. 2 is a perspective view illustrating a small diameter pipe according to the present invention.

As shown in FIGS. 1 and 2, the present invention forms a constricted portion 12A at the rear in a pipe 10 of a tap hole drilling cone 1 connected to the tip of a screw rod via a socket 9. It is characterized in that a short small diameter pipe 12 is slidably inserted therein.

(f) Function When the tap hole 5 is drilled using the tap hole drilling drill 1 of the present invention, the moment the tap hole 5 is completely opened, the bit 8 breaks through the wall and reaches the furnace interior A. A small diameter pipe 12 slidably inserted into the pipe 10 is pushed by the pressure inside the furnace and moves backward inside the pipe 10, stopping at the tip of the screw rod 2 as shown in FIG. This part plays the role of a stopper to prevent hot metal 13 from entering the inside of the hot metal 10 and flowing back.

That is, because the short pipe 12 with a small diameter is constricted at the rear, and because it is a hollow metal piece and is slidably inserted into the pipe 10,
Unlike the metal piece made of round steel as disclosed in Publication No. 35304, the moment Bit 8 breaks through the last wall and reaches the inside of the furnace, it instantly moves backwards due to the furnace pressure and acts as a stopper. fulfill.

In this case, from the small opening provided at the center of the rear end of the small diameter pipe 12 or from the small diameter pipe 12
Even if hot metal tries to enter the screw rod 2 through the gap between the screw rod 2 and the screw rod 2, the small diameter pipe 2 will be pushed by the furnace pressure and will not scrunch because the narrowed part 12A is provided at the rear of the small diameter pipe 12. The backflow of hot metal can be prevented by making the diameter of the small hole in close contact with the Eurod 2 and provided at the rear of the small-diameter pipe 12 sufficiently small to prevent the backflow of hot metal.

In addition, when an abnormal situation such as a sudden change in the furnace internal pressure occurs during blast furnace operation, it is conceivable that hot metal may enter the screw rod 2 even with the present invention.
In preparation for such a case, a pipe made of a metal with high thermal conductivity, for example, a copper pipe 14, is inserted in advance into the screw rod 2 via a stopper 15, as shown in FIG. Therefore, it is effective to quickly solidify the hot metal that flows backward. The solidified pig iron makes it possible to reuse the screw rod 2 by removing the stopper 15 and pulling out the copper pipe 14. In this case, it is preferable to insert the copper pipe in a state in which it is vertically divided into a plurality of pieces, since this improves workability during extraction.

(g) Effects of the invention As described above, according to the invention, in blast furnaces with high internal pressure, troubles caused by backflow of hot metal into the taphole opening machine when opening the taphole can be resolved, and stable operation of the blast furnace and safe work can be achieved. In addition, by inserting a copper pipe into the screw rod in advance, even when the internal pressure of the blast furnace becomes abnormally high during blast furnace operation, hot metal backflow from the tap hole punching machine can be avoided. This has the remarkable effect of avoiding troubles caused by

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a perspective view illustrating a small diameter pipe according to the present invention,
Fig. 3 is a cross-sectional view showing an example in which backflow of hot metal is prevented by the present invention, Fig. 4 is a cross-sectional view illustrating a more desirable embodiment of the present invention, and Fig. 5 explains the operation of drilling a tap hole. FIG. 3 is a side view partially shown in cross section. 1... Cone, 2... Screw rod, 3... Tap hole drilling machine, 4... Support mechanism, 5... Tap hole, 6
... Hot metal, 7 ... Furnace brick, 8 ... Bit, 9
...Socket, 10 ... Pipe, 11 ... Air outlet, 12 ... Small diameter pipe, 12A ... Squeezed part, 13 ... Hot metal that flowed back, 14 ... Copper pipe, 15 ... Stopper.

Claims (1)

[Scope of utility model registration request] In a tap hole drilling drill, in which a pipe is connected to the tip of the screw rod and a drill is provided at the tip of the pipe, a short, small diameter pipe with a constriction at the rear is slidably inserted into the pipe. A tap hole drilling drill characterized by: