JP2884979B2 - Prevention method of black smoke generation in coke oven chimney - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing the generation of black smoke from a chimney of a coke oven in which a plurality of kilns each comprising a carbonization chamber, a combustion chamber and a heat storage chamber are arranged in parallel. is there.

[0002]

2. Description of the Related Art A coke oven has a basic structure of a kiln comprising a carbonization chamber, a combustion chamber and a heat storage chamber, and a large number of these are arranged in parallel to form a furnace group. Black smoke often emanates from the chimneys of such coke ovens. As a general countermeasure for the occurrence of black smoke, it is usual to repair the coke oven wall by repairing it. Therefore, the life of the coke oven is said to be when the generation of black smoke from the chimney is stopped.

FIG. 4 is a diagram for explaining the mechanism of the generation of black smoke in a coke oven. In the figure, 1 is a coke oven, 2 is a carbonization chamber, 3 is a combustion chamber, 14 is an exhaust line, 17 is a chimney,
19 is a brick, 20 is a joint crack. Based on FIG.
The mechanism of black smoke generation will be described. (1) Joint crack 20 of brick 19 between carbonization chamber 2 and combustion chamber 3
Thereby, the carbonized gas in the carbonization chamber 2 flows back to the combustion chamber 3 side,
In the combustion chamber 3, non-combustion of the fuel gas occurs. In particular, when coal is coalesced, a large amount of dry distillation gas is generated. Therefore, a rise in pressure on the carbonization chamber 2 side causes leakage by the joint crack 20 and frequent generation of black smoke from the chimney 17. (2) In the coke oven 1, usually, a furnace group is formed for every 50 to 70 gates (kilns), and combustion switching is performed for each furnace group in a cycle of 20 to 30 minutes. Due to the turbulence of the distribution, the carbonized gas in the carbonization chamber 2 flows back to the combustion chamber 3 side, and non-combustion of the fuel gas occurs.

In order to prevent the generation of black smoke from such a chimney, repair of refractory (brick) joints in the carbonization chamber and the combustion chamber is generally performed. As a method for repairing these furnace walls, for example, Japanese Patent Publication No. 63-16676 discloses that "after repairing a flame on a damaged portion of the furnace wall, the surface of the sprayed body is provided at the tip of an insertion pipe having a cooling water passage formed therein. A furnace wall spraying repair method characterized by abutting an iron member having a built-in vibrator and flattening the surface of a sprayed body by vibration of the iron member, and an insertion tube comprising a multi-tube having a cooling water passage formed therein. And a soldering member attached to the distal end of the insertion tube and having a built-in vibrating device. " Japanese Patent No. 288686 discloses that "inside a combustion chamber of a coke oven, an in-furnace observation device and a refractory spraying device are inserted to detect a penetration crack in a partition wall,
A fireproof material is sprayed from the spraying device to the closed portion of the detected through crack to close the same, and a repair material injection device is inserted into a carbonization chamber of a coke oven, and the crack that closes the combustion chamber side closed portion is cracked into the carbonization chamber. A method for repairing a coke oven wall, characterized by injecting a repair material from the inside to fill the crack. Is disclosed. The above relates to a method for repairing a coke oven wall. Also, various techniques relating to combustion control of individual kilns for the purpose of reducing the amount of carbonization heat of a coke oven and improving coke quality have been disclosed, but there is no technique relating to prevention of black smoke generation in a coke oven.

[0005]

As a problem in the furnace wall repair of the coke oven described above, the repair of the conventional coking chamber mainly involves the kiln opening, and the inner (rear) repair is difficult. Repair of wall joints was insufficient, and as a result, black smoke generation could not be prevented. Preventing the generation of black smoke from this coke oven can make a great contribution to pollution control measures. If the CAA method is applied in the United States, etc., black smoke will be shut down and the operation will be stopped. If it can be prevented, the life of the coke oven can be extended as a result.

[0006] As a result, iron and coke manufacturing companies are now keenly studying furnace wall repair for preventing the generation of black smoke in coke ovens. That is, research on automation and upsizing of furnace wall repair is being promoted. However, 1
There are countless brick joints in one kiln, and it is not known which one is damaged and leads to the generation of black smoke. As a result, the generation of black smoke from the chimney of an old furnace cannot be prevented. . SUMMARY OF THE INVENTION An object of the present invention is to provide a method for preventing black smoke from a coke oven having a newly added pollution control function while maintaining the conventional combustion control function for each kiln so as to solve the above problems. It is what it was.

[0007]

SUMMARY OF THE INVENTION The present invention has a function of adjusting the fuel gas flow rate and the amount of exhaust gas for each kiln, and a large number of kilns comprising a carbonization chamber, a combustion chamber, and a heat storage chamber are arranged in parallel. In the coke oven forming the furnace group, the fuel gas flow rate and the exhaust gas quantity for the desired time based on the following equation are completely closed by the control valve for the individual combustion chamber corresponding to each coal charge. This is a method to prevent black smoke. Ti, n = Ti−1, n + αi, n where, Ti, n: Total closing time of fuel gas and exhaust gas of the next No.n kiln Ti−1, n: Fuel of the previous No.n kiln Fully closed time of gas and exhaust gas αi, n: Correction time due to soot generation state during coal charging of No.n kiln this time

[0008]

According to the present invention, as described above, the accumulated data is fed back based on an empirical formula to each of the combustion chambers corresponding to each of the coals and the fuel gas flow rate and the exhaust gas quantity are fully closed for a desired time by the control valve. By doing so, the generation of black smoke can be appropriately prevented, so that the operation management of the coke oven is easy.

[0009]

FIG. 1 is an explanatory view of a system for preventing black smoke generation from a chimney of a coke oven according to the present invention. In FIG. 1, 1 is a coke oven, 2 is a carbonization chamber, 3 is a combustion chamber, 4 is a heat storage chamber, 5 is a coal hopper, 6 is a coal-equipped car, 7 is a coal-equipped car guidance wireless device, 8
Is an extruder, 9 is a guide car, 10 is an air line, 11 is a fuel gas line, 12 is a fuel gas valve (furnace group), 13 is a fuel gas control valve (individual kiln control), 14 is an exhaust line, and 15 is exhaust. A gas control valve (individual kiln control), 16 is an exhaust gas valve (furnace group), 17 is a chimney, and 18 is a dust concentration meter. As shown in FIG. 1, the coke oven 1 includes a carbonization chamber 2, a combustion chamber 3, and a heat storage chamber 4.
The kilns (gates) made of are made into a basic structure, and in the case of many embodiments, 50 or more kilns are arranged in parallel to form a furnace group.
The coal from the coal hopper 5 is charged into the coking chamber 2 through the coal loading vehicle 6, and the charged coal is heated from the combustion chambers 3 on both sides of the kiln and coke through a constant heating process. Is done. The end of coking is called "fire fall", and the time from charging to the end of coking is called fire time and about 18 hours after normal charging.
It is performed in a cycle of time to 24 hours. After the fire, the coke in the carbonization chamber 2 is extruded by the extruder 8 to the guide wheel 9 side, extinguished, and carried out.

FIG. 2 is a layout diagram of an example of a coke oven combustion system (wirp-ot-type) of the present invention.
As shown in FIG. 2, each furnace group of the coke oven includes a plurality of coking chambers (kilns) 2 and combustion chambers 3 on both sides of the coking chambers 2.
Is configured. Fuel gas is supplied to the combustion chamber 3 through a fuel gas distribution pipe 21, and the heat in the combustion of the fuel gas cokes the coal in the carbonization chamber (kiln) 2. The exhaust gas after combustion is discharged from the exhaust-side flue 23. A fuel gas cock 22 is attached to each fuel gas distribution pipe 21,
Each gas flow rate is adjusted by manual control. As shown in FIG. 2, the carbonization chamber 2 has kiln No.1, No.2, No.3.
… And combustion chambers 3 on both sides are combustion chambers No.1, No.2,
No.3, No.4 ... are arranged separately.

In the coke oven black smoke generation prevention system of the present invention, (1) a fuel gas flow control valve (individual kiln control) 1 is newly installed in the fuel gas supply line 11 for each combustion chamber.
3 (2) Further, a combustion exhaust gas control valve (individual kiln control) 15 is provided in the exhaust line 14, (3) A dust concentration meter 18 is installed in the chimney exhaust line 14, and (4) the coal charging time is grasped. For this reason, the radio equipment for guiding the coal-carrying vehicle 7 was installed between the coal-carrying vehicle 6 and the computer.

The combustion control for each kiln will be described with reference to FIG. 2, the fuel gas from the No. 2 fuel gas control valve 13 flows into the No. 2 and No. 3 combustion chambers, and the combustion exhaust gas flows from the No. 1 and No. 3 exhaust gas control valves 15. Is sucked into. The distribution adjustment of the fuel gas to the combustion chambers of No. 2 and No. 3 is adjusted by the pressure difference between the exhaust gas control valves 15 of No. 1 and No. 3. In the case of the present invention, the exhaust gas control valve 1
5 was made electric, and the fuel gas control valve 13 was a butterfly type electric valve in consideration of the accuracy of flow rate adjustment. The flow rate of the fuel gas is basically automatically controlled by the fuel gas control valve 13, but when the flow rate is out of the range, the fuel gas cock 22 is used to enter an appropriate range. However, in this embodiment, the fuel gas cock 22 is not used. These motorized valves are all controlled by remote control. On the process computer side,
For each appropriate time, calculate the distribution amount of fuel gas and air to each combustion chamber series from the deviation between the target value and the actual value of the combustion chamber temperature,
A command to correct the valve opening of each motor-operated valve is given to the remote control system.

Next, a method for preventing the generation of black smoke from a coke oven chimney according to the present invention will be described. (1) The timing at the start of charging coal into each of the coke oven kilns is set via the coal-equipped vehicle guidance wireless device 7 installed on the coal-equipped vehicle 6.
The information is transmitted from the coal-equipped vehicle 6 to the process computer. (Specifically, the starting point is a high-speed command of a dust collector of a coal-carrying truck.) (2) The process computer sends a command to fully close the fuel gas flow control valve 13 and the exhaust gas control valve 15 of the kiln. (3) The fuel gas flow control valve 13 and the exhaust gas control valve 15 are set for a preset time, usually 0 to 10 minutes (ma).
x) Fully closed. Further, when the combustion switching is performed during the above-mentioned time, the valve in which the fuel gas and the exhaust gas are flowing is targeted. Further, depending on the state of dust generation, the valve does not necessarily have to be fully closed, and the opening can be set arbitrarily. Hereinafter, the above operation is repeated for each coking furnace.

In FIG. 2, when coal is charged in the No. 1 kiln, the flow paths of the fuel gas and the exhaust gas are indicated by solid lines. (However, 20
Every 30 minutes, the route between the solid line and the dotted line is switched. In this case, the fuel gas flow control valve 13, which is fully closed, is no.
Thus, the exhaust gas control valve 15 is fully closed at No. 1. In the above procedure (3), the time when the fuel gas flow control valve 13 and the exhaust gas control valve 15 are fully closed is determined by the exhaust line 14.
Is determined by the process computer based on the dust concentration (volume%) measured by the dust concentration meter 18 provided in the exhaust side flue 23 of the above. The time for shutting off the fuel gas and the exhaust gas differs for each kiln. The time when dust is generated when the dust concentration (volume%) is equal to or more than a certain value is measured in advance by the dust concentration meter 18, and this value is used. Ti, n = Ti-1, n + αi, n where, Ti, n: Total closing time of fuel gas and exhaust gas of the next No.n kiln Ti-1, n: Fuel gas and fuel gas of the previous No.n kiln Fully closed time of exhaust gas (adopted average value of past 10 times) αi, n: Correction time based on the dust generation state at the time of coal charging of No.n kiln this time. The relationship between the value (volume%) of the dust concentration meter and the Ringerman concentration is as shown in the following table. Table Relationship between Dust Densitometer Value and Ringerman Concentration Dust Concentration (Volume%) 0 20 40 60 80 100 Ringerman Concentration 0 1 2 3 4 5

Further, conventionally, since the fuel to be supplied is shut off, the decrease during this time is compensated for. To example kiln 50 Gate, 4000Nm3 / if H is supplying the fuel, when the fuel cut was performed 5 minutes fuel change every 30 minutes ^{[(4000Nm 3 / H) /} 25 Cook] × [5 min / 30 Min] = 267 Nm ³ . Furnace repair of furnace walls, brick joints, etc. is performed depending on the state of the joint cracks, and when the generation of dust is eliminated, the above-described fuel cutoff measures are released. FIG. 3 is a graph showing the relationship between the dust concentration (volume%) and the cutoff time. Charging of the coke oven usually takes place about every 10 minutes. At this time, as described above, non-combustion occurs due to gas leak from the carbonization chamber to the combustion chamber, and the dust concentration increases. For example, a dust concentration of 20% by volume
Assuming that the above time is 120 seconds in the No.n kiln, Ti, n = 60 seconds +120 seconds = 180 seconds However: Ti-1, n is the average time of the past 10 times

The results in one year when the present invention is applied to the above-mentioned Wilput-Ot-type coke oven are shown below. Frequency of abnormal dust generation Before the present invention was carried out After the present invention was carried out 40 times / month 10 times / month As described above, the frequency of black smoke generation from the chimney was reduced by as much as 75%, and as a result, pollution prevention was achieved. In the present invention, only the black smoke generation prevention system of the coke oven chimney has been described, but it goes without saying that an automatic combustion control system and an operation management support system may also be performed.

[0017]

The effect of the present invention is to reduce the amount of carbonization heat and improve the coke quality of the conventional individual kiln combustion apparatus. The present invention aims to prevent pollution by black smoke by determining the total closing time of fuel gas and exhaust gas by feeding back accumulated data. According to the present invention, (1) reduction of black smoke generation frequency from a chimney (2) Prolong the life of the coke oven body (3) Prevent non-combustion of the combustion chamber to reduce local temperature and improve coke quality (4) Prevent non-combustion of the combustion chamber Thereby, the dating (air blowing) of the heat storage chamber, which is a severe operation, is reduced. And the like.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a black smoke generation prevention system for a coke oven according to the present invention.

FIG. 2 is an explanatory view of an arrangement of a combustion system of a coke oven according to the present invention.

FIG. 3 is a graph showing a relationship between a dust concentration and an operation time.

FIG. 4 is an explanatory view of a mechanism of black smoke generation in a conventional coke oven.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coke oven 2 Coking chamber 3 Combustion chamber 4 Thermal storage chamber 5 Coal hopper 6 Coal loading car 7 Coal loading car guidance wireless device 8 Extruder 9 Guide car 10 Air line 11 Fuel gas line 12 Fuel gas valve (furnace group) 13 Fuel gas control valve (Individual kiln control) 14 Exhaust line 15 Exhaust gas control valve (Individual kiln control) 16 Exhaust gas valve (furnace group) 17 Chimney 18 Dust concentration meter 19 Brick 20 Joint crack 21 Fuel gas distribution pipe 22 Fuel gas cock 23 Exhaust side flue

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C10B 21/16 C10B 41/00

Claims (1)

(57) [Claims] 1. A kiln having a function of adjusting a fuel gas flow rate and an exhaust gas amount for each kiln, and arranging a large number of kilns comprising a carbonization chamber, a combustion chamber, and a heat storage chamber in parallel to form a furnace group. Black smoke generation from a coke oven chimney characterized by completely closing a fuel gas flow rate and an exhaust gas amount for a desired time based on the following formula in a coke oven by a control valve in each combustion chamber corresponding to each coal charging. Prevention method. Ti, n = Ti−1, n + αi, n where Ti, n : Total closing time of fuel gas and exhaust gas of the next No.n kiln Ti−1, n: Fuel of the previous No.n kiln Fully closed time of gas and exhaust gas αi, n: Correction time based on the soot generation state during coal charging of No.n kiln this time