JP3948347B2 - Coke oven gas combustion control method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas combustion method for a coke oven, and more particularly to a technique for preventing generation of fine dust (soot) of combustion exhaust gas (hereinafter also referred to as waste gas).
[0002]
[Prior art]
In the coke oven, the combustion chamber and the coking chamber are separated by a single brick. However, as the coke oven ages, the joints of the bricks are cut off, passing through the joints and going from the carbonization chamber to the combustion chamber. The generated gas may leak. The leaked gas may disturb the air-fuel ratio of the combustion chamber, causing incomplete combustion and soot.
[0003]
When this soot is discharged from the chimney as it is, it becomes chimney black smoke. Such chimney black smoke is likely to be generated immediately after the coal charging in which the pressure in the carbonization chamber is particularly increased.
Conventionally, measures have been taken against this black smoke, such as providing a flue dust collector on the inlet side of the chimney. However, this measure has a problem that the amount of investment is enormous although the generation of black smoke in the chimney is zero.
[0004]
On the other hand, in Japanese Patent Application Laid-Open No. 06-063334, downstream of the coke oven waste air valve, the waste air is branched into a new dust collection system and an existing flue system, so that there is a lot of soot or black smoke. Only a lot of waste air is guided to the dust collector. By doing so, the diameter of the newly installed dust collection duct can be reduced, and the dust collector itself can be reduced in size.
However, when there is no space downstream of the waste air valve, a switching damper or a dust collection duct for switching between the dust collection system and the flue system cannot be installed. In addition, in a furnace group composed of a large number of gates, the number of switching dampers is large, so the overall cost is not necessarily low.
[0005]
As another prior art, as disclosed in Japanese Patent Laid-Open No. 06-256764, etc., the leakage gas is completely burned by controlling the flow rate of the fuel gas to the combustion chamber adjacent to the charging furnace when charging coal. There is technology to let you. However, in this case, although the leaked gas burns, there is a problem that the combustion chamber partially becomes excessive in air, and the carbon contained in the brick joints is also burned to promote joint breakage.
[0006]
Further, although the above method is effective, it is necessary to make the entire combustion chamber have an air ratio sufficient to burn the leaked gas, and it is very difficult to control the flow rate of the fuel gas.
Furthermore, the method disclosed in Japanese Patent Laid-Open No. 10-168459, which is another prior art, is a method in which air is blown from a combustion chamber peep hole on the furnace to burn the leaked gas. It is very difficult to control the air flow rate.
[0007]
In addition to the conventional technology, the pressure in the carbonization chamber is controlled by controlling the injection process of the high pressure water spray and the process of opening the damper that cuts off the edge of the dry main. There is a method to prevent the generated gas from leaking to the side, but the pressure control in the carbonization chamber is mostly in the upper space of the carbonization chamber where coal is not charged, and the part where coal is charged Leakage of the generated gas to the combustion chamber side from the joint portion of the furnace wall close to the bottom of the carbonization chamber, particularly near the bottom of the carbonization chamber, cannot be avoided.
[0008]
[Problems to be solved by the invention]
The present invention solves the above-mentioned problems of the prior art by a simple operation without burning out carbon adhering to the joints of the combustion chamber, and can effectively remove fine carbon in the combustion gas. A gas combustion control method and apparatus are provided.
[0009]
[Means for Solving the Problems]
The present invention has solved the above problems by a gas combustion control method and apparatus for a coke oven described in the following sections.
(1) A gas combustion control method in a combustion chamber of a coke oven , wherein the internal pressure of a carbonization chamber charged with coal is measured, and the combustion chamber adjacent to the carbonization chamber is connected to a waste gas side rich gas supply path. A method for controlling gas combustion in a coke oven, wherein non-combustible gas is supplied in accordance with the internal pressure .
(2) pre-Symbol non retardant gas, coke oven gas combustion control method according to the above (1), characterized in that the combustion exhaust gas of the coke oven.
(3 ) A gas combustion control device in a combustion chamber of a coke oven, wherein a path for supplying noncombustible gas from a rich gas supply path on the waste air side of a combustion chamber adjacent to a carbonization chamber charged with coal, and the path In addition, a booster blower that boosts and delivers nonflammable gas, a nonflammable gas flow control valve that is provided in the passage and controls the supply of nonflammable gas, and a pressure gauge that measures the internal pressure of the carbonization chamber And a control device that controls the noncombustible gas flow rate control valve based on the measured value of the pressure gauge and controls the internal pressure of the combustion chamber.
(4 ) The coke oven gas combustion control apparatus according to (3 ), wherein the non-combustible gas is a combustion exhaust gas of a coke oven.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2 by taking a (Curl Still type) coke oven 10 as an example.
In FIG. 1, a two-part Karlstilt coke oven 10 is at the center of the heat storage chamber 31 and the combustion chamber 21 at the extruder side (machine side side, that is, the right side of FIG. 1). 2) and fire extinguisher side (coke side, ie, left side of FIG. 1, fire extinguisher not shown).
[0011]
Then, the introduction of the combustion gas is periodically switched, and the combustion is alternately repeated on the extruder side and the fire extinguisher side every predetermined time (20 to 30 minutes). In addition, as a chamber furnace type coke oven, there are various other types such as a Coppers type, an Otto type, etc. due to the difference in the structure of the combustion chamber and the heat storage chamber respectively devised for uniform heating of the furnace and improvement of thermal efficiency. A furnace is known.
[0012]
The coke oven 10 includes a fuel supply section 11 on each of the extruder side and the fire extinguisher side, and a combustion chamber 21, a carbonization chamber 24, a heat storage chamber 31, a waste air passage 41, and the like. The smoke is discharged from the chimney 44.
The fuel supply unit 11 is provided with a C gas pipe 12 and an M gas pipe 13 respectively so that fuel can be alternately supplied from both ends of the coke oven 10.
[0013]
The carbonization chamber 24 and the combustion chamber 21 are arranged in multiple rows alternately adjacent to form a furnace group, and a coal charging port 22 and a peephole 23 are provided on the upper surface thereof.
Further, as shown in FIG. 1, the combustion chamber 21 of the coke oven 10 is formed with a complicated path through which fuel gas and air are circulated. A heat storage chamber 31 is provided.
[0014]
The flue gas passes through the heat accumulating chamber 31 as shown by the flue gas flow 32 and transfers heat to the bricks forming the heat accumulating chamber 31, and then passes through the exhaust path 41 such as the small flue 42 and the large flue 43. After that, it is discharged from the chimney 44 to the outside air.
When the poor gas (mixed gas: M gas) is combusted, the fuel gas is sent to the M gas pipe 13 and at the same time, air is sent as shown as the air flow 14. These fuel gas and air are heated separately by exchanging heat with high-temperature bricks separately via the heat storage chamber 31, and merge in the combustion chamber 21 and burn. By doing in this way, sensible heat of combustion gas can be used effectively.
[0015]
On the other hand, during combustion of rich gas (coke oven gas: C gas), fuel gas and air are supplied directly to the burner in the combustion chamber 21 without passing through the heat storage chamber 31. The rich gas (C gas) contains a large amount of hydrocarbon gas, and if it is kept at a high temperature, it may be decomposed to generate soot, so that it is usually burned without preheating.
In the coke oven 10 to which the present invention shown in FIG. 1 is applied, the flue gas stream 32 is branched by, for example, a large flue 43 and pressurized by a booster blower 20 and disposed on the waste air side (chimney 44 side). Connected to the supply path to the rich gas supply path 12b which is a C gas branch pipe.
[0016]
Then, combustion exhaust gas is supplied from a waste gas-side rich gas supply passage 12b at the lower part of the combustion chamber 21 on both sides of the carbonization chamber 24 into which coal is charged. At this time, as shown in FIG. 2, the pressure of the carbonization chamber 24b into which the coal is charged is measured with the pressure gauge 17 together with the pressure of the combustion chamber 21 on both sides thereof, and the supply is made according to the measured pressure values. Adjust the flow rate of the combustion exhaust gas. That is, for a while after the start of coal charging, the pressure inside the carbonization chamber 24b is higher than the pressure inside the combustion chamber 21, so the pressure measurement value inside the combustion chamber is almost equal to the pressure measurement inside the carbonization chamber 21. Therefore, the flow rate of the combustion exhaust gas to be supplied is adjusted.
[0017]
By doing so, the combustion exhaust gas flow 32 can be supplied to the combustion chambers adjacent to the combustion chamber to increase the pressure of the combustion chamber in accordance with the pressure increase in the carbonization chamber that occurs during coal charging. Leakage of gas generated to the room side can be prevented, and generation of black smoke from the chimney can be eliminated.
Moreover, in the present invention, since the flue gas stream 32 is supplied to the lower part of the combustion chamber 21 on the waste air side, the carbon present in the joints of the combustion chambers 21 is not burned, and there is a concern of promoting the breakage of brick joints. Absent. Further, since the supply amount of the flue gas stream 32 is adjusted according to the pressure in the carbonization chamber 24b and the combustion chamber 21, the inflow of fuel gas and air into the combustion chamber 21 without excessive pressure increase in the combustion chamber Therefore, there is no concern that the combustion of the fuel gas in the combustion chamber will be hindered.
[0018]
In the above description, it has been described that the combustion exhaust gas stream 32 is supplied to the combustion chamber 21 on both sides of the carbonization chamber 24 into which the coal is charged, but this is a non-combustible gas in which the combustion exhaust gas is most easily obtained. This is because it is possible to introduce an incombustible gas such as nitrogen gas into the combustion chamber 21.
[0019]
【Example】
The operation was carried out by applying the gas combustion method of the coke oven according to the present invention to the operation of a Karlstilt coke oven having 102 carbonization chambers. This is an example of the present invention.
In the present invention example, the combustion exhaust gas was supplied to the combustion chamber on both sides of the carbonization chamber charged with coal of the coke oven according to the internal pressure of the carbonization chamber. The supply was performed from the waste gas side rich gas supply branch at the bottom of the combustion chamber, and was performed for 10 minutes from the start of coal charging.
[0020]
On the other hand, the operation which applied only the poor gas combustion using M gas was implemented as a prior art example. In the conventional operation, the pressure in the combustion chamber was 4 to 5 mmAq.
As a result of the above, the transition of the soot concentration after charging the coal is as shown in FIG. 3, and in the example of the present invention, it can be seen that the soot concentration after charging the coal is greatly reduced. Here, the soot concentration index is a relative value indicating the transition of the soot concentration in the conventional example, with the maximum value of the soot concentration in the combustion exhaust gas after charging the coal being 1. The dust concentration was determined as the amount of dust in the combustion exhaust gas sampled for 1 minute each by inserting a sampling pipe into the waste gas valve portion of the combustion chamber and sampling at a constant speed.
[0021]
That is, in the example of the present invention, the pressure in the combustion chamber was 6 to 7 mmAq, which was almost equal to the pressure in the carbonization chamber, so that it was possible to achieve a dust concentration reduction of 90% or more.
[0022]
【The invention's effect】
By applying the present invention, the leakage of generated gas from the carbonization chamber side to the combustion chamber side is reduced, the fine carbon mixed in the combustion exhaust gas of the coke oven is greatly reduced, and the chimney is installed without installing a flue dust collector. It became possible to maintain the amount of dust discharged from the water at a very low level.
[0023]
In addition, since the combustion exhaust gas, which is an incombustible gas, is supplied to the lower part of the combustion chamber, the carbon existing in the joints of the combustion chamber is not burned, and the joint breakage of the bricks is not promoted.
[Brief description of the drawings]
FIG. 1 is a schematic view of a coke oven to which the present invention is applied.
FIG. 2 is a schematic diagram showing a gas combustion flow of a coke oven to which the present invention is applied.
FIG. 3 is a graph showing the change over time in the dust concentration of the present invention example and the conventional example.
[Explanation of symbols]
10 (Carlstil type) coke oven
11 Fuel supply section
12 C gas piping
12b Rich gas supply path (C gas branch pipe)
13 Poor gas supply channel (M gas piping)
14 Air flow
16 Waste air valve
17 Pressure gauge
18 Control unit
19 Combustion exhaust gas (non-combustible gas) flow control valve
20 Booster blower
21 Combustion chamber
22 Coal charging entrance
23 Peephole
24 Carbonization chamber
24b Carbonization chamber (charging coal)
31 Thermal storage room
32 Flue gas flow
41 Waste air route
42 Small flues
43 Large flues
44 Chimney

Claims (4)

A method for controlling gas combustion in a combustion chamber of a coke oven,
The internal pressure of the carbonization chamber charged with coal is measured, and a noncombustible gas is supplied to the combustion chamber adjacent to the carbonization chamber from the rich gas supply path on the waste air side according to the internal pressure. Coke oven gas combustion control method. The method for controlling gas combustion in a coke oven according to claim 1, wherein the non-combustible gas is used as combustion exhaust gas from a coke oven. A gas combustion control device in a combustion chamber of a coke oven,
A path for supplying non-combustible gas from a rich gas supply path on the waste air side of the combustion chamber adjacent to the carbonization chamber charged with coal;
A booster blower that boosts and delivers non-flammable gas to the path;
A non-flammable gas flow control valve provided in the path for adjusting the supply of non-flammable gas;
A pressure gauge for measuring the internal pressure of the carbonization chamber;
A control device for controlling the incombustible gas flow rate control valve based on the measured value of the pressure gauge and controlling the internal pressure of the combustion chamber;
A gas combustion control device for a coke oven, comprising: The coke oven gas combustion control apparatus according to claim 3 , wherein the non-combustible gas is a combustion exhaust gas of a coke oven.

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