Coal gas heating method for iron-making blast furnace

Abstract

The invention discloses a coal gas heating method for an iron-making blast furnace, which comprises the following steps of: introducing furnace burning coal gas and combustion-supporting air into a coal gas heating furnace to burn and heat lattice bricks, closing the furnace, stopping feeding the furnace burning coal gas and the combustion-supporting air, purging the space in an inerting furnace, and feeding normal-temperature metallurgical pressurized coal gas to an inlet of the coal gas heating furnace, the coal gas is heated through heat transfer of checker bricks of the coal gas heating furnace, is sent out from an outlet of the coal gas heating furnace, is mixed with part of cold coal gas in a gas mixing chamber according to a certain proportion before entering the blast furnace and then is injected into the blast furnace, and when the temperature of the mixed coal gas does not meet user requirements, other coal gas heating furnaces which burn the furnace are replaced to send the coal gas; and the replaced gas heating furnace is stuffy, residual gas in the furnace is discharged to a low-pressure gas main pipe, the space in the inerting furnace is purged, then the residual gas discharging direction is switched to a flue main pipe, the gas heating furnace is subjected to next-round furnace burning, and circulation is conducted in sequence.

Description

technical field

[0001] The invention belongs to the technical field of blast furnace ironmaking, and in particular relates to a gas heating system and heating technology. Background technique

[0002] The hot blast heating furnace required for traditional blast furnace ironmaking adopts the hot blast furnace heating mode, and the heating medium is mostly air containing 21% oxygen. The furnace gas and combustion-supporting air are used to burn the checker bricks in the furnace in the combustion chamber of the hot blast furnace. When the temperature of the checker bricks rises to 1250-1400°C, the furnace operation is stopped, and the cold air is blown in from the cold air inlet of the hot blast stove. The mixed air is mixed with the cold air in a certain proportion, and the mixed air reaches the temperature required by the user, and finally sent to the blast furnace; when the temperature of the mixed air does not meet the user's needs, replace the hot blast stove that has comp...

Examples

Embodiment approach

[0023] see Figure 1 to Figure 2 , a gas heating method for ironmaking blast furnaces,

[0024] A gas heating method for an ironmaking blast furnace. After the gas heating furnace is fired, an inert gas is introduced to drive the waste gas out of the flue to the mouth of the flue. 2 , CO is lower than 1%, the metallurgical normal temperature pressurized gas is introduced into the inlet of the gas heating furnace, and it is sent out from the outlet after heating. -1300°C mixed gas, and then inject the mixed gas into the blast furnace, when the temperature of the mixed gas is lower than 1200°C, replace other fired furnaces to feed gas to the gas heating furnace. Close the inlet valve and outlet valve of the gas heating furnace after the gas supply is completed, open the residual gas recovery valve in the furnace, discharge the residual high-pressure gas in the furnace to the low-pressure gas main pipe, and introduce inert gas after the pressure in the furnace drops to the press...

Embodiment

[0036] In September 2019, the 2500m³ blast furnace of Bayi Iron and Steel Co., Ltd. was repaired, and the three top-fired gas heating furnaces used in the blast furnace were simultaneously transformed, and the gas heating furnace low-pressure gas discharge channel, double hot air valve and nitrogen sealing mechanism were installed, and the safety control system was installed. Added CO, O 2 The on-line monitoring chain control system, after the intermediate repair, coke oven gas was blown into the gas heating furnace for the test, and the gas was successfully heated to 1100°C through the gas heating furnace and injected into the blast furnace.

[0037] In this process, first use the 1# gas heating furnace to supply air, first open its flue valve, and pass the furnace gas and combustion-supporting air into the 1# gas heating furnace, and the fed gas and air are in the combustion chamber of the 1# gas heating furnace Combustion, when the temperature of the vault of the 1# gas hea...

technical field

[0001] The invention belongs to the technical field of blast furnace ironmaking, and in particular relates to a gas heating system and heating technology. Background technique

[0002] The hot blast heating furnace required for traditional blast furnace ironmaking adopts the hot blast furnace heating mode, and the heating medium is mostly air containing 21% oxygen. The furnace gas and combustion-supporting air are used to burn the checker bricks in the furnace in the combustion chamber of the hot blast furnace. When the temperature of the checker bricks rises to 1250-1400°C, the furnace operation is stopped, and the cold air is blown in from the cold air inlet of the hot blast stove. The mixed air is mixed with the cold air in a certain proportion, and the mixed air reaches the temperature required by the user, and finally sent to the blast furnace; when the temperature of the mixed air does not meet the user's needs, replace the hot blast stove that has comp...

Examples

Embodiment approach

[0023] see Figure 1 to Figure 2 , a gas heating method for ironmaking blast furnaces,

[0024] A gas heating method for an ironmaking blast furnace. After the gas heating furnace is fired, an inert gas is introduced to drive the waste gas out of the flue to the mouth of the flue. 2 , CO is lower than 1%, the metallurgical normal temperature pressurized gas is introduced into the inlet of the gas heating furnace, and it is sent out from the outlet after heating. -1300°C mixed gas, and then inject the mixed gas into the blast furnace, when the temperature of the mixed gas is lower than 1200°C, replace other fired furnaces to feed gas to the gas heating furnace. Close the inlet valve and outlet valve of the gas heating furnace after the gas supply is completed, open the residual gas recovery valve in the furnace, discharge the residual high-pressure gas in the furnace to the low-pressure gas main pipe, and introduce inert gas after the pressure in the furnace drops to the press...

Embodiment

[0036] In September 2019, the 2500m³ blast furnace of Bayi Iron and Steel Co., Ltd. was repaired, and the three top-fired gas heating furnaces used in the blast furnace were simultaneously transformed, and the gas heating furnace low-pressure gas discharge channel, double hot air valve and nitrogen sealing mechanism were installed, and the safety control system was installed. Added CO, O 2 The on-line monitoring chain control system, after the intermediate repair, coke oven gas was blown into the gas heating furnace for the test, and the gas was successfully heated to 1100°C through the gas heating furnace and injected into the blast furnace.

[0037] In this process, first use the 1# gas heating furnace to supply air, first open its flue valve, and pass the furnace gas and combustion-supporting air into the 1# gas heating furnace, and the fed gas and air are in the combustion chamber of the 1# gas heating furnace Combustion, when the temperature of the vault of the 1# gas hea...

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