JPH07109459A - Method for utilizing exhaust gas in coke dry-quenching equipment - Google Patents

Abstract

PURPOSE:To effectively utilize a circulating gas contg. a remaining combustible gas derived from coke before the circulating gas is discharged as an exhaust gas, when a semicoke is baked in a prechamber by supplying the circulating gas to a fuel pipeline while the gas has a high calory. CONSTITUTION:A semicoke is used which is pushed out of a coke oven chamber of a chamber oven at such a low temp. that the temp. of coke at the center of the chamber is 600-900 deg.C. Coke is produced by charging the semicoke into the prechamber of coke dry-quenching equipment and introducing a specified amt. of air into the prechamber to burn a combustible gas remaining in the semicoke to thereby bake it. During the baking the concn. of an unburnt combustible gas contained in a circulating gas in a pipeline is measured on-line, the curculating gas is effectively utilized before it is discharged out of the system as an exhaust by supplying the gas, while it has a high calory, to a fuel pipeline such as a blast furnace gas pipeline. The water content of the gas is measured on-line to calculated the temp. of water supplied to bring the gas to the dew point or higher, and the gas of a high calory is supplied to an incinerator as a fuel for preheating the water supplied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of using a released gas in a coke dry fire extinguishing facility (hereinafter referred to as "CDQ"). Coke is produced by introducing air into the CDQ pre-chamber and heating it to produce product coke.
Effective use of flammable gas that remains in the circulating gas without being burned due to boiler inlet temperature restrictions, etc., even when the DQ is operating at maximum steam generation (Max), as a desorption gas outside the system The present invention relates to a method of using the emitted gas in CDQ. Here, the “semi-coke” defined in the present invention is 600 to 600 in the carbonization chamber of the chamber type coke oven.
It refers to coke in the middle of dry distillation, which has 1 to 5% of residual volatile matter (VM) derived from charging coal after finishing dry distillation at 900 ° C.
The temperature of this semi-coke is the average temperature of the center temperature in the coal measured at the height 1/2 of the carbonization chamber directly below the charging hole.

[0002]

2. Description of the Related Art Conventionally, air supply to a CDQ is limited to adjustment of circulating gas components and introduction of coke-combustion air as auxiliary heat when heat input is reduced, and therefore the amount of emitted gas is small. In addition, since the finished coke which has been subjected to dry distillation until the center temperature in coal is 1000 ° C in a room type coke oven is input, the amount of residual combustible gas (VM) derived from coke is small, and the combustible gas remaining in the emission gas is It was almost never.

However, air is introduced into the semi-coke produced in the CDQ pre-chamber in the CDQ pre-chamber by removing the coke from the kiln at a low temperature of 600 to 900 ° C. in the center of the carbonization chamber of the chamber type coke oven, and mainly residual combustible gas is removed. In the coke manufacturing method of burning and heating and firing (Japanese Patent Application Laid-Open No. 2-194087 and Japanese Patent Application Laid-Open No. 2-199191), a large amount of air needs to be supplied, and the amount of emitted gas is also increased accordingly. Will increase. Further, since a large amount of combustible gas (VM) derived from coke is brought into the system, the combustible gas remaining in the emission gas may increase. The method for producing coke described in the above publication only discloses that the coke discharged from the low temperature kiln is rapidly heated and fired in the pre-chamber of the CDQ, and nothing is disclosed about the effective use of the emission gas. Absent.

On the other hand, there is known a coke dry-type fire extinguishing method which recovers and utilizes as fuel gas at the time of high calorie due to fluctuation of gas components in circulating gas (Japanese Patent Publication No. 58-17789).
This is a technique corresponding to CDQ which is normally operated, and does not correspond to the coke production method of the present invention in which coke discharged from a kiln is burned at a low temperature. Further, there is no disclosure about effective use of fuel for preheating water supply and necessity of preheating water supply.

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to evaporate a circulating gas in which a combustible gas derived from coke remains when a semi-coke produced by firing at a low temperature is fired in a pre-chamber and quality is improved. The present invention is to provide a method for using the emitted gas in a coke dry fire extinguishing facility, which effectively uses the emitted gas when it is released to the outside of the system.

[0006]

Means for Solving the Problems As a result of earnest research for solving the above-mentioned problems, the present inventor has found that when semi-coke produced by firing at a low temperature is fired in a pre-chamber and quality is improved. When the circulating gas in which the combustible gas derived from coke remains is released to the outside of the system as a release gas, it was found that the above object can be achieved by effectively treating this release gas, and the present invention has been completed. Of.

That is, according to the present invention, the coke temperature of the central portion of the carbonization chamber of the chamber type coke oven is kiln-fired at a low temperature of 600 to 900 ° C., and the semi-coke is blown into the pre-chamber of the coke dry fire extinguishing equipment. Introduced, mainly burns residual combustible gas, and calcinates it to produce product coke. In the production of coke, when the semi-finished coke is calcined in the pre-chamber, the coke derived from the coke in the circulating gas pipeline of the coke dry fire extinguishing equipment Coke dry fire extinguishing system, which is characterized by supplying the fuel gas to the fuel pipe when the calorific value of the flammable gas is released to the outside of the system as a effluent gas and recovering it as fuel. This is how to use the emitted gas in the equipment. Further, the present invention, in the production of the above coke, combustible gas derived from coke corresponding to the water concentration in the circulating gas in the circulating gas line of the coke dry fire extinguisher when firing the semi-coke in the pre-chamber. Coke dry extinguishing system characterized in that when the circulating gas containing the remaining unburned components is discharged to the outside of the system as effluent gas, this effluent gas is supplied to the combustion furnace for feedwater preheating to control the feedwater preheating temperature rise range. This is how to use the emitted gas in the equipment. Further, in the production of the above coke, the combustible gas derived from coke corresponds to the moisture concentration in the circulating gas in the circulating gas pipeline of the coke dry fire extinguisher when firing the semi-coke in the pre-chamber. When the circulating gas with the unburned portion of is discharged to the outside of the system as a effluent gas, this effluent gas is supplied to the combustion furnace for preheating feed water to control the feed water preheating temperature rise range, and when the effluent gas is high in calories. It is a method of using the emitted gas in a coke dry fire extinguishing facility, which is characterized in that it is supplied to a fuel pipe and recovered and used as fuel. The "coke" defined in the present invention includes blast furnace coke, foundry coke, non-ferrous metal refining coke, and coke for other purposes.

[0008]

According to the present invention, a large amount of air needs to be supplied when the semi-finished coke kiln discharged at a low temperature of 600 to 900 ° C. is burned by CDQ and quality is improved, and accordingly, in the circulating gas pipeline of the dry fire extinguishing equipment. Since the amount of combustible gas derived from coke increases in the circulating gas, the concentration of the combustible gas in the circulating gas is measured online, and when the circulating gas is released to the outside of the system as the emitted gas, the emitted gas has a high calorie content. It is sometimes recovered as fuel gas. Further, the present invention measures the water concentration in the circulating gas online to calculate the feed water temperature above the dew point and measures the corresponding feed water temperature rise as a high calorie measure as an anticorrosion measure for the pipe due to the rise in the dew point when the water content in the circulating gas rises. Is used as fuel for the combustion furnace for preheating feed water. Further, according to the present invention, the desorbed gas is recovered as a fuel gas as described above and is also used as a fuel for a feed water preheating combustion furnace.

[0009]

EXAMPLES Examples of the present invention will be specifically described below with reference to the drawings, but the present invention is not limited to these examples.

First, the superiority of the present invention will be described by a comparative test. This test was conducted using the room-type coke oven 1 which is the production facility shown in FIG. In FIG. 1, 2 is an extruder, 3 is a coal handling vehicle, 4 is a semi-coke receiving vehicle, 5 is a semi-coke charging facility, 6 is CDQ, 7 is steam recovery facility, 8 is coke unloading facility, and 9 is closed. Circulation path,
10 is a pre-chamber. The equipment specifications of the chamber type coke oven 1 are as follows: carbonization chamber (mm) ... furnace height 5500 mm x furnace width 4
50 mm x furnace length 15700 mm. The operating conditions of the room type coke oven 1 are as shown in Table 1 below. In addition,
In the comparative example, the one charged under the same conditions as the present invention was tried under the condition that the operating conditions of the present invention were not satisfied. The following operating conditions are average values of 45 kilns.

[0011]

[Table 1]

Coke temperature kiln variation temperature [° C] (average value of 45 kilns), minimum coke temperature in the carbonization chamber, current value variation of extrusion kiln [A] (range R of 45 kiln current values) under the above operating conditions. Table 2 and Table 3 below show the residual volatile matter (VM) of the semi-coke obtained by
Shown in.

[0013]

[Table 2]

[0014]

[Table 3]

As is clear from the results shown in Tables 1 to 3, under the conditions of the present invention, the semi-coke coking can be stably carried out on an industrial scale. On the other hand, in the comparative example, the variation in the kiln temperature of the semi-finished coke increased, and the variation in the coke temperature in the carbonization chamber increased.Therefore, a kiln in which the extrusion current value from the carbonization chamber exceeded the control upper limit,
Implementation on an industrial scale proved impossible.

Next, an example of the control method of the present invention will be described based on the flow sheet of the control system shown in FIG. In FIG. 2, 11 is a CDQ prechamber. 12
Is a circulating gas pipeline attached to the pre-chamber 11, and the circulating gas pipeline 12 is provided with a SECO (preheat heat exchanger) 13, a blower 14, and a boiler 15.

The calorific value of the gas is converted into calories by measuring the gas component 16 in the circulating gas from the circulating gas line 12, and the amount of the diffused gas recovered from the circulating gas line 12 in the recovery model 17 is supplied from the first control valve 18. The emission gas (excess recovery gas) is controlled and supplied to the blast furnace gas pipe (BFG pipe) 20 via the second control valve 19 and is recovered as fuel gas.
In addition, 21 is a dust collector. Here, a blast furnace gas pipe (BFG pipe) is targeted as an example of the fuel pipe.

Further, the water dew point of the circulating gas is calculated and the acid dew point is estimated from the measurement result of the water concentration 16 in the circulating gas from the circulating gas pipe 12, and the feed water temperature raising model 22 is used to
The required SECO feed water temperature is obtained, the required amount of recovered gas is calculated from the required amount of preheat of the supplied water and the calorie of the recovered gas, and the second control valve 9 is controlled to supply the degassed gas to the combustion furnace 23 for preheating of the supplied water. Control the preheating temperature rise range.

Next, FIG. 3 shows changes in the amount of CDQ emission gas and the amount of recovered gas in the present invention and the comparative example. Here, the comparative example is a case where the CDQ equipment is used. As is clear from FIG. 3, in the present invention, the total amount of the emitted gas is effectively used as the recovered gas when the calorific value of the emitted gas increases (750 Kcal / Nm ³ or more in the illustrated example).

In this example, the coke temperature of the center of the carbonization chamber of the chamber type coke oven was kiln-fired at a low temperature of 600 to 900 ° C., and the semi-coke was introduced into the pre-chamber of the CDQ to mainly introduce air. In the production of coke that burns and burns residual combustible gas, the concentration of the combustible gas in the circulating gas is measured online when the coke discharged at a low temperature is fired in the pre-chamber, and the circulating gas is released. As the emission gas is released as a fuel gas when it is released to the outside of the system as a high-calorie fuel gas, the water concentration in the circulating gas is measured online to calculate the feedwater temperature above the dew point, and the corresponding feedwater temperature rise is calculated as a high-calorie value. The emitted gas is used as a fuel for the combustion furnace for preheating feedwater, and the temperature rise range for preheating feedwater is controlled.

The above-mentioned embodiment is a method of utilizing the diffused gas, in which the diffused gas is recovered as the fuel gas as described above, and is used as the fuel of the combustion furnace for preheating the feedwater to control the feedwater preheating temperature rise range. That is, it may be a method of utilizing the diffused gas for recovering the diffused gas as a fuel gas or a method of utilizing the diffused gas for controlling the rising range of the feedwater preheating by using it as the fuel of the combustion furnace for feedwater preheating.

[0022]

According to the present invention, the high calorie emission gas can be effectively used and the cost of coke production can be reduced. Further, the thermal efficiency of the CDQ can be improved by using the high calorie diffused gas as the fuel for preheating the feed water. Water dew point,
The online management of the acid dew point can prevent SECO squeeze increase, corrosion, etc., and enable stable operation. By eliminating the dust collection and emission of high-calorie gas, operational instability factors such as abnormal combustion in dust collection pipes are eliminated.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of equipment for producing coke in a combination process of a room-type coke oven and CDQ according to the present invention.

FIG. 2 is a flow sheet showing an example of a method of using the emitted gas in the coke dry fire extinguishing equipment of the present invention.

FIG. 3 is a diagram showing changes in the calorific value of CDQ emitted gas, the amount of emitted gas, the amount of recovered gas, etc. of the present invention and a comparative example.

[Explanation of symbols]

 1-room type coke oven 2 extruder 3 coal car 4 semi-coke receiving vehicle 5 semi-coke charging equipment 6 CDQ 7 steam recovery equipment 8 coke unloading equipment 9 closed circulation path 10 pre-chamber 11 CDQ pre-chamber 12 circulating gas pipe Line 13 Preheat heat exchanger 14 Blower 15 Boiler 16 Gas component measurement, moisture measurement 17 Recovery model 18 First control valve 19 Second control valve 20 Blast furnace gas pipe 21 Dust collector 22 Water supply temperature raising model 23 Water supply preheating combustion furnace

Claims (3)

[Claims] 1. A kiln is discharged at a low temperature of 600 to 900 ° C. in the center of a carbonization chamber of a room-type coke oven, and the semi-coke is introduced into a pre-chamber of a coke dry-type fire extinguisher facility to mainly introduce air. Burning the remaining flammable gas,
In the production of coke that turns into product coke by firing, when semi-finished coke is fired in the pre-chamber, a circulating gas in which the unburned portion of the combustible gas derived from the coke remains in the circulating gas pipeline of the coke dry fire extinguisher equipment. A method for using the emitted gas in a coke dry fire extinguishing facility, characterized in that, when the emitted gas is released to the outside of the system, the emitted gas is supplied to a fuel pipe when the calorie is high and is used as fuel. 2. The coke temperature of the center of the carbonization chamber of the chamber coke oven is kiln-fired at a low temperature of 600 to 900 ° C., and the semi-coke is introduced into the pre-chamber of a coke dry-type fire extinguisher, mainly by introducing air. Burning the remaining flammable gas,
In the production of coke that turns into product coke by firing, when firing semi-finished coke in the pre-chamber, it is combustible derived from coke that corresponds to the moisture concentration in the circulating gas in the circulating gas pipeline of the coke dry fire extinguisher equipment. A coke dry type, characterized in that, when the circulating gas in which the unburned portion of the gas remains is released to the outside of the system as a effluent gas, this effluent gas is supplied to the combustion furnace for preheating feedwater to control the feedwater preheating temperature rise range. How to use diffused gas in fire fighting equipment. 3. The coke temperature of the central part of the carbonization chamber of the room type coke oven is kiln-fired at a low temperature of 600 to 900 ° C., and the semi-coke is introduced into the pre-chamber of a coke dry fire extinguisher facility to mainly introduce air. Burning the remaining flammable gas,
In the production of coke that turns into product coke by firing, when firing semi-finished coke in the pre-chamber, it is combustible derived from coke that corresponds to the moisture concentration in the circulating gas in the circulating gas pipeline of the coke dry fire extinguisher equipment. When the circulating gas, in which the unburned gas remains, is released to the outside of the system as effluent gas, this effluent gas is supplied to the combustion furnace for feedwater preheating to control the feedwater preheating temperature rise range, and the effluent gas high calorie A method of using the released gas in a coke dry fire extinguishing facility, which is characterized in that it is sometimes supplied to a fuel pipe and recovered and used as fuel.