JPH0892616A - Operation of coke packed bed type smelting reduction furnace - Google Patents

Abstract

PURPOSE: To provide an operating method for assuring the long-time stable operation of a smelting reduction furnace by preventing the blow-by of in- furnace gases to the charging pipe hopper of the furnace, thereby preventing the deterioration of a sealing valve disposed in the charging pipe hopper. CONSTITUTION: The pressure P0 in the furnace 2 and the pressure PH in the charging pipe hopper 4 are respectively measured by pressure gages 6, 7 and the pressure difference ΔP therebetween is calculated and is compared with a pressure difference set value ΔP0 . The amt. of the gaseous N2 from a gaseous N2 supply source 8 into the charging pipe hopper 4 is controlled by automatically controlling a shut off valve 11 in such a manner that ΔP>=ΔP0 is attained. The caption number 3 denotes the charging pipe of coke 12 and the caption number 5 denotes the sealing valve to shut off the pressure in the furnace 2 and the atm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a coke packed bed type smelting reduction furnace having a charging tube for charging coke at the top of the furnace.

[0002]

2. Description of the Related Art Generally, in a coke packed bed type smelting reduction furnace, the only raw material to be charged into the furnace through a furnace top charging device is coke, and when the temperature in the furnace rises, the temperature from the top to 700 It reaches 1000 ° C. The smelting reduction furnace disclosed in Japanese Patent Application Laid-Open No. H5-271734 disclosed by the present inventors has been made to project from the furnace top into the furnace 2 as shown in FIG. 1 in order to protect the equipment such as the furnace top charging device. The charging pipe 3 is provided, and the inside of the charging pipe 3 is always filled with the coke 12. The high temperature gas in the furnace 2 is prevented by the material seal of the coke 12 from the furnace top charging device, especially the charging pipe. It is prevented from flowing into the hopper 4 directly above (hereinafter referred to as the charging pipe hopper).

FIG. 2 is a detailed explanatory view of the seal valve 5 provided in the charging pipe hopper 4 of FIG. 1, and performs pressure shutoff between the high-pressure furnace and the atmosphere. Since the heat resistance of the seal rubber 13 is low, it is important to protect the seal valve 5. In addition, 15 shows a valve seat, and a dotted line shows a state in which the valve body 14 is open.

[0004]

In order to prevent the high temperature rising gas in the furnace from flowing into the charging pipe hopper only by the material seal of the coke filled in the charging pipe,
The technical means as described above has the following problems.

1. The coke material seal is not perfect and there is some gas rise through the coke grain gap. 2. Since the water in the coke evaporates while the charged coke descends in the charging pipe, a large amount of steam rises together with the above gas especially in the operation of spraying water into the furnace for the purpose of lowering the temperature inside the furnace. . 3. If the coke consumption in the furnace becomes abnormally fast,
When the gas rises remarkably and the coke in the charging pipe becomes empty in the worst case, the gas in the furnace directly flows into the charging pipe hopper.

That is, because of the above problems, the inside of the charging pipe hopper is in a high temperature atmosphere and the seal rubber of the seal valve is damaged, or dust rises easily on the seal rubber due to the rise of steam. As a result, the seal valve leaked, making operation impossible. An object of the present invention is to provide a method for operating a coke packed bed smelting reduction furnace which solves the above-mentioned problems and prevents the gas in the furnace from rising and flowing into the charging pipe hopper. is there.

[0007]

The present invention solves the above problems and is applied to a method for operating a coke packed bed type smelting reduction furnace in which coke is charged into the furnace from the furnace top through a charging pipe. The following method was adopted. That is, the pressure (P _H ) in the charging pipe hopper directly above the charging pipe and the pressure (P _O ) in the furnace at the top of the furnace are continuously measured and their pressure difference (ΔP =
P _H -P _O) is calculated, and the pressure difference setting value Δ which is set in advance
A method for operating a coke packed bed smelting reduction furnace, characterized in that an inert gas is automatically blown into the charging pipe hopper so that ΔP ≧ ΔP _O when P _O (a positive number). is there.

[0008]

The operation of the present invention will be described with reference to FIG. The coke packed layer type smelting reduction furnace instrumentation pipe hopper 4 directly above instrumentation pipe 3 arranged to protrude to one of the furnace top portion of the furnace, an inert gas such as N ₂ gas, N ₂ gas supply source 8, the N ₂ gas blowing pipe 9, the flow rate adjusting valve 10, and the shutoff valve 11 are continuously blown to keep the pressure inside the charging pipe hopper 4 higher than the pressure inside the furnace 2. The N ₂ gas blown into the charging pipe hopper 4 flows into the furnace 2 via the charging pipe 3 and the rise of the furnace gas can be prevented.

Even if the coke in the charging pipe 3 is emptied due to some abnormality and the furnace 2 and the charging pipe hopper 4 are directly communicated with each other, the pressure balance causes the gas in the furnace to rapidly rise. It is possible to prevent the rise into the charging pipe hopper 4. As a result, the seal valve 5 arranged above the charging pipe hopper 4 is not exposed to high temperatures, and the steam rising with the gas in the furnace can be blocked, so that the seal rubber of the seal valve 5 is not damaged or damaged. It is possible to prevent dust from adhering to the seal valve 5 and eliminate the seal leakage of the seal valve 5.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of an apparatus and its control flow in which the present invention can be suitably implemented. Inside the furnace 2 and the charging pipe hopper 4, pressure gauges 6 and 7 for measuring the internal pressure are installed, and the respective pressures are continuously measured. The charging pipe hopper 4 is connected to a blow pipe 9 connected from a supply source 8 of an inert gas such as N ₂ gas, and a flow control valve 10 and a shut-off valve 11 which can be remotely operated are provided in a path of the blow pipe 9. It is arranged.

[0011] In the operation of the coke packed layer type smelting reduction furnace, the furnace pressure is determined by the furnace pressure gauge 6 P _O and, measured in instrumentation pipe hopper manometer the instrumentation pipe hopper pressure P _H
By calculating the pressure difference ΔP between the pressure difference ΔP and the pressure difference setting value ΔP _O set in advance and opening / closing the shutoff valve 11 according to the result. The pressure P _H is kept slightly higher than the furnace pressure P _O. That is, when ΔP <ΔP _O , the shut-off valve 11 is opened and N ₂ gas is blown into the charging pipe hopper 4 to make the charging pipe hopper 4
Increase the pressure inside. When ΔP ≧ ΔP _O, the shutoff valve 11 is closed to stop blowing N ₂ gas.

In the actual operation, the blowing into the charging pipe hopper 4 is performed.
Embedded N₂ Gas is in the charging coke while it is in the coke
Since it is discharged into the furnace 2 through the gap, the shut-off valve 11 is almost continuous.
The pressure in the charging pipe hopper 4 rises although it continues to open.
ΔP and ΔP to prevent overshooting_O By comparison with
The shutoff valve 11 should be opened and closed. Also blow N ₂ 
Flow control valve 10 to keep the amount of gas as small as possible
Adjust.

In this embodiment, the internal volume of the smelting reduction furnace is 140 m ³ , the amount of tapping is 140 ton / day, the pressure at the top of the furnace (in the furnace at the top of the furnace) is 0.5 kg / cm ² · G, and the charging pipe hopper is used. Differential pressure setting value between internal pressure and furnace pressure ΔP _O = 0.1k
It is g / cm ² . In the prior art, a seal leak occurred in the seal valve after three months of operation, and the seal rubber was replaced each time, but according to the present invention, there is no rise of gas or steam into the charging pipe hopper. , The seal valve is no longer damaged, and it has been possible to operate for over a year without replacing the seal rubber.

[0014]

According to the present invention, the coke packed bed type smelting reduction furnace can be stably operated for a long period of time, and it is excellent in improving productivity and reducing facility maintenance costs.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an apparatus that can preferably implement the present invention and a control flow thereof.

FIG. 2 is a detailed explanatory diagram of the seal valve of FIG.

[Explanation of symbols]

1 Smelting Reduction Furnace 2 Furnace 3 Charging Pipe 4 Charging Pipe Hopper 5 Seal Valve 6 Furnace Pressure Gauge 7 Charging Pipe Hopper Pressure Gauge 8 N ₂ Gas Supply Source 9 N ₂ Gas Injection Piping 10 Flow Control Valve 11 Shutoff Valve 12 coke 13 seal rubber 14 valve body 15 valve seat P _O ... inner pressure P _H ... instrumentation pipe hopper pressure [Delta] P ... pressure difference [Delta] P _O ... pressure difference setpoint

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seisuke Kouko 1 Kawasaki-cho, Chuo-ku, Chiba-shi Inside the Kawasaki Steel Co., Ltd. (72) Inventor Takashi Ushijima 1 Kawasaki-cho, Chuo-ku, Chiba Kawasaki Steel Co., Ltd. Chiba Inside the steel mill

Claims (1)

[Claims] 1. A method of operating a coke packed bed type smelting reduction furnace in which coke is charged into the furnace from the furnace top through a charging pipe, the pressure (P _H in the charging pipe hopper immediately above the charging pipe. ) And the pressure (P _O ) in the furnace at the top of the furnace are continuously measured, and the pressure difference (ΔP = P _H −P _O ) between them is calculated, and the preset pressure difference set value is ΔP _O (a positive number). ), ΔP ≧
A method for operating a coke packed bed type smelting reduction furnace, characterized in that an inert gas is automatically blown into the charging pipe hopper so as to obtain ΔP _O.