JPH0625346U - External combustion hot air stove connection structure - Google Patents

Abstract

(57) [Abstract] [Purpose] Excessive expansion and contraction of expansion joints, and excessive concentration of stress at the joint between the connecting beam and the dome iron skin alleviate the need for repair of connecting pipes Type hot blast stove proposal. [Structure] Reinforcing plates at the bases connecting the connecting pipe to the heat storage chamber and the combustion chamber dome are connected by a plurality of connecting beams so as to surround the connecting pipe.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an external combustion hot-air stove which is an auxiliary equipment of a blast furnace.

[0002]

[Prior art]

 Generally, an external heating type hot stove and an internal heating type hot stove are known as one of the facilities for preheating air blown into a blast furnace or the like. For example, Maruzen Co., Ltd., October 1979, 3rd edition Iron and Steel Handbook II, Ironmaking and Steelmaking, page 301, shows several types of external combustion hot stoves. These external heating hot blast stoves are separated into a combustion chamber that guides and burns blast furnace gas and coke gas and a heat storage chamber that stores the amount of heat, and these are connected by a dome connecting pipe at the top of the furnace. And supplying hot air.

In general, the dome connecting pipe has an expansion joint 6 that absorbs expansion and contraction due to changes in internal pressure and changes in hot air temperature, as shown in FIGS. 3 and 5. However, in order to prevent the expansion joint 6 from excessively expanding in the event of large fluctuations in the furnace pressure, earthquakes, or wind resistance, in Japanese Patent Laid-Open No. 50-104707, FIGS. As shown in, the heat storage chamber dome 3 and the combustion chamber dome 4 are connected by the connecting beam 7d. Further, as shown in FIG. 5, there is a case where the straight body portions of the heat storage chamber 1 and the combustion chamber 2 are connected by a connecting beam 7e.

[0004]

[Problems to be solved by the device]

 However, according to the method disclosed in Japanese Patent Laid-Open No. 50-104707, a large stress is generated at the root portion (connection portion) 11 of the connecting beam 7d and the dome iron skins 3 and 4 shown in FIG. There is a problem of waking up and breaking. In the method of connecting the straight body portions with the connecting beam 7e shown in FIG. 5, expansion / contraction of the expansion joint 6 is repeated due to fluctuations in the furnace pressure and the furnace temperature, and the internal lining of the expansion joint 6 is repeated. There is a problem that the refractory material of 1 is cracked or dropped, and the expansion joint 6 is burned out.

Therefore, when repairing the above troubles, the operation must be stopped and the dome iron skin and expansion joint must be replaced. Of course, during this repair, the blast furnace operation must be stopped. There is a problem. The present invention solves the above problems and alleviates the excessive expansion and contraction of expansion joints and the excessive stress concentration at the joint between the connecting beam and the dome iron skin, thus greatly reducing the need for repair. It is intended to provide a combustion hot stove.

[0006]

[Means for Solving the Problems]

 The present invention relates to an external combustion hot-air stove in which the side walls of the heat storage chamber dome and the combustion chamber dome are connected by a dome connecting pipe, and a reinforcing plate at the base portion connecting the connecting pipe and each dome is provided with a plurality of connecting beams. The external combustion hot-air stove is characterized in that the connecting pipe is connected so as to surround the connecting pipe.

In the present invention, the connection between the connecting plate and the reinforcing plate of the base portion connecting the connecting pipe and each dome can be usually connected by welding. In addition, it is desirable that 10 or more connecting beams should be installed symmetrically so as to surround the connecting pipe. This is because if the number is small, stress corrosion cracking is likely to occur at the connection part.

[0008]

[Action]

 In the present invention, as shown in FIGS. 1 and 2, a plurality of connecting beams 7a are provided on the respective dome of the heat storage chamber dome 3 and the combustion chamber dome 4 and the reinforcing plate 9 at the base of the connecting pipe 5. Disperses the stress that occurs when pressure is applied. Further, since the connecting pipe expansion joint 6 is not excessively expanded by the connecting beam 7a, the inner bricks of the connecting pipe 5 and the connecting pipe expansion joint 6 are not damaged.

Therefore, it is possible to obtain a hot-blast stove which has a long life and requires no repair.

[0010]

Embodiment FIG. 1 is an overall schematic view showing an embodiment of the present invention, and FIG. 2 is a partially enlarged view of the vicinity of the connecting pipe 5 of FIG. The connecting pipe 5 and each dome 3, 4 are connected via a reinforcing plate 9. 6 is an expansion joint. Reference numeral 7a is a connecting beam, and both ends thereof are connected to respective reinforcing plates 9 by welding.

By the way, in an outer-burning hot-air stove with a dome distance of 14 m and a connecting pipe outer diameter of 5 m, 16 connecting beams 7a of the present invention are installed so as to surround the connecting pipe 5, and the blowing pressure is about 4.5 kg. / Cm ² , the blast temperature was about 1300 ° C, the combustion time was 2 hours, and the blast time was 2 hours. One cycle showed that the distance between the apex of the heat storage chamber dome and the combustion chamber dome increased by 25 mm when the air was blown. However, it decreased to 2.5 mm.

Further, by connecting beams 7a installation, stress at the root portion of the connecting bar 7e are those which is conventionally 1600 kg / cm ² was reduced to 850 kg / cm ^2. Furthermore, the connection pipe expansion joint 6 was heated up to 350 ° C in a few months after the operation due to damage to the inner brick, but by implementing the present invention, a low temperature of about 80 ° C was maintained.

As described above, by carrying out the present invention, the hot-blast stove can be stably operated for a long period of time. In the embodiment shown in FIG. 1, the straight body portions of the heat storage chamber 1 and the combustion chamber 2 are not joined by the beam 7e, but the beam 7e is not always necessary in the present invention.

[0014]

[Effect of device]

 In the present invention, by attaching a plurality of connecting beams to the base of the dome and the connecting pipe, a large stress is not generated in the connecting beam and its base, and the connecting pipe can be expanded and contracted in a small amount. Therefore, it is possible to prevent stress corrosion cracking and damage to the refractory of the inner lining, and repair of the relevant part is hardly required, and the operation of the external heating hot stove is stable. Therefore, the effect of contributing to stable operation of the blast furnace is great.

[Brief description of drawings]

FIG. 1 is a side view showing the overall structure of an external combustion hot stove according to the present invention.

FIG. 2 is a partially enlarged view of the vicinity of the connecting portion in FIG.

FIG. 3 is a side view showing the overall structure of a conventional external combustion hot-air stove.

FIG. 4 is a plan view of FIG.

FIG. 5 is a side view showing the overall structure of a conventional external combustion hot-air stove.

[Explanation of symbols]

 1 heat storage chamber 2 combustion chamber 3 heat storage chamber dome 4 combustion chamber dome 5 connecting pipe 6 expansion joint 7 connecting beam 8 flange 9 stiffening plate 10 ring gutter 11 high stress place

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Katsuhiko Yanagisawa 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Co., Ltd. Chiba Works

Claims (1)

[Scope of utility model registration request] 1. An external combustion hot-air stove in which the side walls of the heat storage chamber dome and the combustion chamber dome are connected by a dome connecting pipe, and a plurality of reinforcing plates at the base portion connecting the connecting pipe and each dome are connected. An external combustion hot air stove characterized in that the connection pipes are connected so as to surround the connection pipes.