JP2863608B2 - How to raise the temperature of the coke oven - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for raising the temperature of the end of a kiln mouth to improve non-uniform carbonization when producing coke in a coke oven. More specifically, the present invention relates to operation control of a burner provided at the end flew for raising the temperature of the end flew.

[Conventional technology]

In general, as a method for improving the non-uniform carbonization in the coke oven in the furnace length direction, a method of introducing only fuel gas into the end flue (for example, “iron is steel”, Vo172, s843, 198)
6) Alternatively, a method of introducing fuel gas and combustion air into the end flues (for example, JP-A-63-170487) is known.

In each of these methods, a new hole is provided in the end flute, a new burner is installed in this hole, and the amount of fuel gas and combustion gas exceeds the fuel gas and combustion air supplied from the existing coke oven. Attempts to introduce air into the end flute.

In this method, the burner is installed in a high-temperature atmosphere, and is operated by being incorporated into the heating system of the coke oven. In order to maintain stable operation for a long period of time, it is necessary to consider a nozzle (burner opening) blockage due to decomposition of C gas as a fuel gas under a high-temperature atmosphere. The problem exists.

For this reason, as a material for the burner, ceramic (Japanese Utility Model Laid-Open No. 2-10446) is used because the atmosphere to be used is a high temperature atmosphere (1100 to 1300 ° C.). Ceramic burners are superior to metal burners in terms of heat resistance, but have a problem in terms of thermal shock resistance. That is, in the burner provided at the end flue, according to the combustion side switching cycle of the coke oven, every 20 minutes or every 30 minutes, a state in which cold fuel gas and combustion air are introduced, and a state in which high-temperature combustion gas is discharged outside the furnace. The state is switched to a state in which the gas is exhausted, and a thermal shock is applied with the introduction of the cold fuel gas and the combustion air.

As a conventional technique for preventing the thermal shock, there is a ceramic burner (Japanese Patent Laid-Open Publication No.
-8293). The technology disclosed in Japanese Patent Application Laid-Open No. 2-8293 is to alleviate the quenching of a ceramic burner when fuel gas and combustion air are introduced by heat retained in a porous ceramic contained in the burner, thereby preventing damage due to thermal shock. You do it.

[Problems to be solved by the invention]

In the prior art described above, the burner is made of ceramics to enhance heat resistance, and porous ceramics are installed inside the ceramic burner to increase thermal shock resistance. There is no change in the necessity of operation, and therefore, there is a problem that the selection of a practical ceramic material and the structure are greatly restricted.

In addition, the effect of thermal shock mitigation due to the heat possessed by the porous ceramics is not sufficient, and long-term safe operation is difficult to obtain in actual operation, and burners must be replaced regularly due to damage or clogged nozzles. There was also a problem in terms of cost.

Furthermore, when replacing the burner, it is extremely difficult to remove the ceramic fragments by using the holes provided in the coke oven wall for installing the burner, and a part of the ceramic fragments is located inside the end flute. However, there is a problem that it is unavoidable to remain in the resin.

At the time when clogging occurs due to the decomposed carbon attached to the opening at the burner tip or when clogging is predicted, air is introduced, and the clogged carbon is removed with the introduced air. However, there is a problem in that it is difficult to remove the attached carbon by the introduced air, the recovery cannot be performed in a short time, and the operation is hindered.

The cause of the problem in the above-mentioned conventional technology is as follows.
This means that the burner itself for raising the temperature of the end flue is used after being heated to the same high temperature as the ambient temperature in the coke oven.

Therefore, the present invention has been made in order to solve the above-mentioned problems in the prior art, and has as a technical problem to keep the temperature of the burner itself provided at the end flute of the coke oven at a low temperature at all times. An object of the present invention is to broaden the selection range of the burner material, to operate the burner in a safe state without damage for a long period of time, and to prevent carbon from being attached to the opening of the burner tip.

[Means for solving the problem]

Means of the present invention for solving this technical problem is to control the combustion by introducing fuel gas and combustion air via a burner to the extruder side and the extinguishing car side of the coke oven at each end flue. This is a method of raising the temperature of the end flue to a predetermined temperature, that is, a method of raising the temperature of the flue at the end of the coke oven, and supplying cooling air instead of air for combustion to the burner of the flue on the exhaust side.

In order to obtain a safer end flue heating operation, it is preferable to introduce an inert gas into the fuel gas introduction pipe for the burner for a certain time immediately before the end of the heating operation.

[Action]

Usually, for heating the coke oven, in order to perform combustion in the furnace length direction, an end flue for introducing a fuel gas and combustion air and an end flue for pulling down combustion exhaust gas are provided.
The operation of each end flew is switched every 20 minutes or 30 minutes.

Since the burner provided on the heating side end flue introduces fuel gas and combustion air, the burner is cooled by the introduced fuel gas and combustion air, and is not heated to the ambient temperature in the coke oven.

Similarly, instead of the combustion air, cooling air is introduced into the burner provided on the exhaust-side end flue that pulls down the combustion exhaust gas, so that the heating of the burner by the combustion exhaust gas is greatly suppressed.

That is, in the present invention, the burners provided at each end flue are always kept in a cooled state by the fuel gas and the combustion air or the cooling air.

Since the introduction of the cooling air to the burner is performed in place of the combustion air, the introduction of the cooling air to the burner can be achieved by using the introduction path of the combustion air to the burner as it is.

As described above, since the burner is always in a cooled state, it is not actually heated to 700 ° C. or more, and therefore, generation of carbon due to decomposition of the fuel gas is suppressed. Carbon deposition will be greatly reduced.

In particular, when an inert gas is introduced into the fuel gas introduction pipe for the burner for a certain time immediately before the end of the heating operation,
There is no carbon adhesion to the burner openings.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings showing an example of an end flute heating device configured to carry out the method of the present invention.

FIG. 1 shows an example of a pipe for introducing fuel gas G and air E to the burner 1. The pipes provided on the extruder side MS and the fire extinguisher side CS of the end flute 8 of the coke oven 7 have exactly the same configuration. Therefore, FIG. 1 shows the piping on the fire extinguishing vehicle side CS.

The piping is composed of a fuel gas system and an air system, and the fuel gas system is connected to a gas main pipe 11 from a fuel gas supply source,
A gas pipe 12 for switching and supplying the fuel gas G to the extruder side MS and the fire extinguishing car side CS; and a gas branch pipe 13 branched from the gas pipe 12 and connected to the burner gas pipe 5 of each burner 1. Similarly, the air system includes an air pipe 23 into which air is sent from the fan 22, a combustion air pipe 25 and a cooling air pipe 31 branched from the air pipe 23, and a combustion air pipe.
A combustion air branch pipe 26 that branches off from 25 and is connected to the burner air pipe 6 of each burner 1, and a cooling air branch pipe 32 that branches off from the cooling air pipe 31 and is connected to the burner air pipe 6 of each burner 1 It is composed of

In the gas pipe 12, the supply direction of the fuel gas G, which is provided near the connection point side of the gas main pipe 11, is controlled by the extruder side MS and the fire extinguisher side CS.
A gas switching valve 14 for switching to one of the following:
A gas first flow meter 16 for measuring the total amount of supplied gas is provided. Each gas branch pipe 13 has a gas control cock for controlling the amount of fuel gas G actually supplied to the burner 1.
15 and a gas second flow meter 17 for measuring the amount of the supplied fuel gas G are provided.

The combustion air pipe 25 is provided with a combustion air switching valve 27 for opening and closing the pipe line, and a combustion air flow meter 29 for measuring the total amount of supplied combustion air. 31
Is provided with a cooling air switching valve 33 for opening and closing the pipeline, a cooling air flow meter 35 for measuring the total amount of supplied cooling air, and a combustion air branch pipe 26 with a burner 1.
A combustion air control cock 28 for controlling the amount of combustion air supplied to the combustion air check valve 30 for preventing the cooling air from entering the combustion air branch pipe 26 is provided. Similarly, the cooling air branch pipe 32 includes a cooling air adjusting cock 34 for controlling the amount of cooling air supplied to the burner 1,
A cooling air check valve 36 for preventing combustion air from entering the cooling air branch pipe 32 is provided. The burner air pipe 6 is provided with an air flow meter 24 for measuring the actual amount of air supplied to each burner 1.

In addition, the gas pipe 12 upstream of the branch point of the gas branch pipe 13
An inert gas pipe 37 provided with an inert gas supply valve 38
Is connected.

As shown in FIG. 2, each burner 1 is attached to the end flue 8 of a coke oven 7 to which a high calorific value coke oven gas pipe Cg and a low calorific value mix gas pipe Mg are attached. Specifically, a burner mounting hole 10 is opened in the end fluff furnace wall 9 forming the end flew 8, and the burner 1 is mounted in the burner mounting hole 10 by being inserted from outside the coke oven 7.

When the burner 1 is used, it is necessary to switch the combustion side in accordance with the combustion switching cycle of the coke oven 7 equipment, and various methods are conceivable for this switching method, an example of which is shown in FIG.

FIG. 3 (a) shows a simplified configuration of a mechanical switching system, which is the most commonly used system as a combustion switching device for coke oven equipment, and is provided at a connection portion between the gas branch pipe 13 and the burner 1. A switching cock 20 is provided, and the switching cock 20 is connected to a tension bar 19 reciprocally driven by a hydraulic cylinder 18, and the opening and closing of the switching cock 20 is switched by the movement of the tension bar 19.

FIG. 3 (b) shows a simplified configuration of a shut-off valve type switching system, in which a shut-off valve is provided at a connection portion between the gas branch pipe 13 and the burner 1.
An opening and closing of the shut-off valve 21 ′ is switched by the solenoid valve 21.

FIG. 3 (c) shows a simplified configuration of the N ₂ purge system using the inert gas shown in FIG.
14 is shut off to stop supplying the fuel gas G to the gas pipe 12,
Next, the inert gas supply valve 38 is opened, and the inert gas N ₂ gas is supplied from the inert gas pipe 37 into the gas pipe 12. In the case of this N ₂ purge method, it is easy to ensure the sealing performance and the reliability, and it is possible to achieve the prevention of backfire and the purging of the burner 1 and the gas pipe 12.

FIG. 4 is a time chart of the switching operation of each valve at the time of switching the combustion side. The switching from the extruder side MS combustion to the fire extinguisher side CS combustion, and the extinguisher side CS combustion from the extinguishing car side CS combustion. The state of switching to is shown.

In the extruder side MS combustion state, the gas switching valve 14 of the extinguisher side MS is closed while the gas switching valve 14 of the extruder side MS is open, and the combustion air switching valve of the extruder side MS. Combustion air switching valve 27 on the fire extinguishing car CS side while 27 is open
Is closed, while the cooling air switching valve 33 on the extruder MS is closed, whereas the cooling air switching valve 33 on the fire extinguishing car CS is open, and inert gas is supplied to the extruder MS and the fire extinguishing car CS. The valves 38 are both closed.

When it is time to switch the combustion side from this state,
Gas switching valve 14 of the extruder-side MS is switched to the closed state at t _1, fully opened after confirming that it is now closed the inert gas supply valve 38 of the extruder-side MS predetermined time, Extruder side MS gas pipe 12 and gas branch pipe 13 and burner 1
To achieve a purge inside.

In time t ₂ after the purge achieved, closes the combustion air switching valve 27 of the extruder-side MS, it opens the cooling air switching valve 33 of the same extruder side MS, cooling the burner 1 of the extruder-side MS Supply air for use.

Make sure that the supplied heating effect of preventing the burner 1 of the extruder side MS by the cooling air is in a state capable of sufficiently exhibited, at time t _3, extinguishing vehicle side CS of cooling air switching valve 33 At the same time, the combustion air switching valve 27 is opened, and the supply of combustion air to the burner 1 of the fire extinguishing car CS is started.
Open the gas switching valve 14 of the extinguishing vehicle side CS from this point t ₃ at t ₄ after a predetermined time period, the fuel gas G is supplied to the burner 1 of the extinguishing vehicle side CS, it has been heated in the fire fighting vehicle side CS is started Is done.
The switching of the combustion side from the fire extinguisher side CS to the extruder side MS is performed in a similar procedure.

FIG. 5 shows a specific structural example of the burner 1 used to carry out the method of the present invention.

The burner 1 has a double-pipe structure of an inner cylinder 2 and an outer cylinder 3 and forms an air passage between the inner cylinder 2 and the outer cylinder.
The inside is a fuel gas G passage. A burner air pipe 6 is connected to the rear end of the outer cylinder 3 projecting out of the end fluff furnace wall 9.
At the rear end, a burner gas pipe 5 is provided continuously. Inner cylinder 2
A swivel plate 4 is provided at the tip end to improve the mixing property between the fuel gas G and the air E.

Regardless of whether the burner 1 is located on the heating side or the exhaust side, the burner 1 is constantly supplied with air E for combustion or cooling.
In this case, as shown in FIG. 5, by providing an air passage between the inner cylinder 2 and the outer cylinder 3, the entire burner 1 can be cooled by the air E. It can be achieved uniformly and effectively. In particular, the front end opening of the inner cylinder 2, which is the injection port of the fuel gas G, is always air E
Since it is placed in an atmosphere, it is not heated to 700 ° C. or more, and thereby the fuel gas G is not decomposed by heating, so that there is no possibility that the burner 1 is blocked by carbon adhesion.

FIG. 6 shows an example of the temperature measurement at the tip end of the burner 1 having the structure shown in FIG.

As is apparent from the temperature measurement results shown in FIG. 6, the temperature of the burner 1 on the heating side is suppressed to about 300 to 400 ° C. by the cooling action of the supplied fuel gas G and combustion air. On the exhaust side due to switching of the combustion side, the temperature rises sharply. However, the heating temperature when the burner 1 is on the exhaust side is maintained at a value of about 620 ° C. and 700 ° C. or less by supplying cooling air to the burner 1. The change pattern of the heating temperature of the burner 1 can be controlled by the cooling air amount after the switching of the heating side and the supply timing. It is sufficient that the amount of cooling air supplied to the burner 1 is 5 Nm ³ / hr or less.

〔The invention's effect〕

The present invention has the above-described configuration, and has the following effects.

By always supplying air to the burner, the cooling effect for the burner is always obtained, so that the temperature of the burner can be kept at 700 ° C or less, so that normal metal materials can be used as the burner manufacturing material. In addition, it is possible to eliminate breakage and spalling when the burner is made of ceramics, and it is possible to eliminate various problems regarding heat resistance of the burner manufacturing material.

Since the burner temperature can be kept below 700 ° C,
The fuel gas is not decomposed, and the occurrence of a burner blockage accident due to carbon adhesion can be eliminated.

Since the degree of thermal shock to the burner is small, and this does not cause burner breakage and spalling,
In addition, since the burner is not blocked by the adhesion of carbon, the burner can be operated stably and satisfactorily for a long period of time.

The burner heating suppression effect is only to supply air to the burner on the exhaust side, and the obtained heating suppression effect can be almost set by the supply air amount, so that it is easy to carry out and the degree of heating suppression is almost freely controlled. be able to.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a pipeline configuration configured to carry out the method of the present invention. FIG. 2 is a simplified diagram showing an example of an assembling configuration of a burner to a coke oven. FIG. 3 shows a configuration example of a heating side switching system in a fuel gas supply line to a burner. FIG. 3 (a) shows a mechanical system, FIG. 3 (b) shows a solenoid valve system, and FIG. FIG. 3 (c) shows the N ₂ purge type, respectively. FIG. 4 is a diagram showing a time chart of the switching operation of the gas switching valve, the inert gas supply valve, the combustion air switching valve, and the cooling air switching valve of the pipeline during the switching operation between the heating side and the exhaust side. It is. FIG. 5 is a longitudinal sectional view showing an example of the configuration of a burner in which the method of the present invention is performed. FIG. 6 is a diagram showing an example of a temperature measurement result of a burner tip when the method of the present invention is performed. DESCRIPTION OF SYMBOLS 1; burner, 2; inner cylinder, 3; outer cylinder, 4; swirl plate, 5; burner gas pipe, 6; burner air pipe, 7; coke oven, 8; end flew, 9; end flue furnace wall , 10; burner mounting hole, 11; gas main pipe, 12; gas pipe, 13; gas branch pipe, 14; gas switching valve, 15;
Gas control cock, 16; gas first flow meter, 17; gas second flow meter, 18; hydraulic cylinder, 19; tension bar, 20; switching cock, 21; solenoid valve, 21 '; shut-off valve, 22; fan, 23; air pipe, 24; air flow meter, 25; combustion air pipe, 26; combustion air branch pipe, 27; combustion air switching valve, 28; combustion air control cock, 29; combustion air flow meter, 30 ; Combustion air check valve, 3
1; cooling air pipe, 32; cooling air branch pipe, 33; cooling air switching valve, 34; cooling air control cock, 35; cooling air flow meter, 36; cooling air check valve, 37; Active gas pipe, 38; inert gas supply valve, MS; extruder side, CS; fire extinguisher side, Mg; mixed gas pipe, Cg; coke oven gas, G; fuel gas, E; air.

Claims (2)

(57) [Claims] 1. A fuel gas and combustion air are introduced into the extruder side (MS) and the fire extinguishing car side (CS) end flues (8) of a coke oven (7) through a burner (1). When the temperature of the end flute (8) is raised to a predetermined temperature by controlling the combustion, cooling air is supplied instead of the combustion air to the burner (1) of the exhaust end flute (8). Coke oven end flew heating method. 2. The coke oven end flue heating method according to claim 1, wherein an inert gas is introduced into the fuel gas introduction pipe for the burner (1) for a predetermined time immediately before the end of the heating operation.