JP3275791B2 - Abnormal early detection method of coke oven carbonization room - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to damage to furnace wall bricks in a carbonization chamber and generation of carbon deposits, which are major causes of extrusion troubles such as clogging and holding down during coke extrusion which hinders the productivity of a coke oven. The present invention relates to a method for early detection of abnormalities in a carbonization chamber of a coke oven in order to early detect the occurrence of an extrusion trouble and prevent an extrusion trouble.

[0002]

2. Description of the Related Art Most of coke ovens in Japan were built during the period of rapid economic growth, and their lifespan will reach the beginning of the 21st century. Widely used. However, the capital investment of the alternative furnace is not only enormous, but also at present, the next-generation coke production technology that can be used in a 100% blast furnace has not yet been developed.

For this reason, it is an important issue for steel companies how to extend the life of the current coke oven. Factors that determine the life of a coke oven include:
The degree of damage to the furnace wall brick in the coking chamber, the furnace length, and the inclination of the furnace itself due to expansion in the direction of the furnace group are considered. It is said that such damage greatly progresses when extruding troubles such as coke jamming and holding are caused, in addition to deterioration over time.

[0004] In the operation of a coke oven, when coke that has been carbonized is extruded from a coking chamber into a coke bucket or a fire extinguishing car through a door, the coke may become stuck in the coking chamber, causing jamming and stopping. There is. This phenomenon is called an extrusion trouble, and is one of the serious troubles that occur during the removal from the coke kiln. In the event of this clogging or blocking, the kiln discharging work must be interrupted and the coke in the carbonization chamber must be scraped out manually until it can be extruded. Not only does the coke productivity decrease, but the prolonged time until it can be extruded increases the amount of heat consumed, leading to an increase in coke production costs and adding a large load to the coke oven furnace wall brick. Therefore, the coke oven life will be shortened due to problems such as damage to the furnace body and collapse of the furnace wall.

Conventionally, extrusion troubles in a coke oven have been controlled by the extrusion current peak value of an extrusion ram of an extruder. If the extrusion current peak value tends to increase, it is necessary to extend the holding time or to increase the extrusion current. Regarding the measures, we have taken measures such as removing carbon adhering to the furnace wall of the carbonization chamber and repairing furnace wall bricks and hearth bricks, and have worked to prevent blockage and blockage. However, since the extrusion current peak value of the extrusion ram includes factors other than the extrusion load, such as the amount of acceleration of the motor and the amount of brake, there is a problem in the management accuracy only with the peak value of the extrusion current.

As a method of managing the extrusion load, a method of judging from the waveform of the current value or the motor torque value of the motor for driving the extrusion beam (Japanese Patent Laid-Open No. 8-53676), the power consumption of the motor for driving the extrusion beam, (Japanese Patent Laid-Open No. 8-134)
No. 458) has been proposed.

[0007] Further, as a method of grasping the carbon adhesion state on the wall of the carbonization chamber furnace, a method of detecting the extrusion current of a coke extruder and detecting the carbon adhesion status from the abnormal current peak value after the peak value of the extrusion current. (Special Publication 55-5
No. 558), the extrusion load applied to the coke extruder of each kiln was detected by converting it into a time integrated value of electric power or a time integrated value of current, and set in advance for each kiln based on the history of each kiln. A method for detecting carbon adhesion by comparing with a reference value (Japanese Patent Publication No. 60-4238), measuring the change over time of the load received by a coke extruder, and measuring the peak value of the load until the time elapsed from the start of kiln discharge. The distance that the coke extruder has moved is determined in advance, and the position of carbon adhering to the wall of the coking chamber furnace is detected based on this distance (Japanese Patent Laid-Open No. Sho 62-349).
82 publication) has been proposed.

[0008]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 8-536 / 1996
The method disclosed in Japanese Patent Publication No. 76 is a coke oven having dozens to hundreds of carbonization chambers in one furnace group, and requires a great deal of effort to check the waveform of the chart paper of the current recorder of all kilns every day. And Further, the method disclosed in Japanese Patent Application Laid-Open No. 8-134458 is similar to the method disclosed in Japanese Patent Application Laid-Open No. 1-247483, in that whether the increase in extrusion power consumption is due to the adhesion of carbon to the furnace wall or not. It cannot be determined whether the damage is due to damage such as surface roughness or chipping of the wall, and it is necessary to determine by visual observation of the furnace wall.

The method of judging the state of carbon deposition from the peak value of the abnormal current after the peak value of the extrusion current disclosed in Japanese Patent Publication No. 55-5558 discloses a method in which several tens to a hundred or more carbonization chambers are provided in one furnace. In a coke oven having a large amount of labor every day to check the waveform of the chart paper of the current recorder of all kilns, and the abnormal current peak value due to the carbonization of the carbonization chamber furnace wall does not always appear .
Also, a method for detecting carbon adhesion by comparing a time integrated value of electric power or a time integrated value of current disclosed in Japanese Patent Publication No. 60-4238 with a reference value previously set for each kiln based on the history of each kiln. It is not possible to determine whether the increase in extrusion load is due to the adhesion of carbon to the furnace wall of the coking chamber or to damage such as roughening or chipping of the furnace wall of the coking chamber. We decided to respond later, and could not respond promptly. Further, Japanese Patent Application Laid-Open
No. 34982 discloses the method of detecting the carbon position from the distance that the coke extruder has moved by the time elapsed from the start of kiln discharge of the measured load peak value due to the adhesion of carbon to the furnace wall of the coking chamber. , It was not possible to judge whether it was caused by damage such as rough surface or breakage of the carbonization chamber furnace wall, and the subsequent response was determined by visually observing the carbonization chamber furnace wall, and prompt response was not possible .

[0010] An object of the present invention is to solve the above-mentioned disadvantages of the prior art, and to damage and adhere brick walls of a coking chamber (hereinafter simply referred to as furnace wall bricks), which is a major cause of extrusion troubles that hinder productivity of a coke oven. An object of the present invention is to provide an abnormal early detection method of a carbonization chamber of a coke oven in which the generation of carbon is distinguished from each other and detected at an early stage while specifying the generation site, thereby preventing an extrusion trouble.

[0011]

According to the method for detecting abnormalities in a coke oven carbonization chamber at an early stage of the present invention, when extruding coke from a coke oven carbonization chamber, the presence or absence of abnormalities is determined from a load waveform applied to an extrusion ram of an extruder. Based on the CO concentration at the time of coal filling by combustion exhaust gas analysis at the knee piece section on the exit side of the heat storage chamber that leads to the withdrawal flue of the combustion chamber adjacent to the carbonization chamber, It is determined whether the damage is due to damage or due to attached carbon. In this way, the presence / absence of an abnormality and the abnormal position are determined from the load waveform applied to the extrusion ram at the time of coal loading by combustion exhaust gas analysis at the knee piece portion on the outlet side of the heat storage chamber, which is connected to the withdrawal flue of the combustion chamber adjacent to the carbonization chamber. By determining the cause of the abnormality based on the CO concentration in the carbonization chamber, it is possible to quickly determine whether or not there is an abnormality in the carbonization chamber and whether the abnormality is due to damage to the furnace wall brick or to the attached carbon. By taking the countermeasures at an early stage, it is possible to prevent the extrusion trouble beforehand and to contribute to prolonging the life of the coke oven.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the case where carbonization is present in the carbonization chamber and the furnace wall is damaged, the space in the carbonization chamber is not a quasi-rectangular shape in a normal state, but has a locally narrow or wide shape. Coal also cokes with locally distorted shape. This local distortion requires an excessive force because the coke passes through the distorted portion when the coke is discharged from the coke kiln, and an excessive load is applied to the extrusion ram of the extruder, and excessive extrusion is performed on the furnace wall brick. Load also increases, which contributes to the progress of furnace wall damage.

Usually, when extruding coke, coke is extruded against the frictional resistance of the furnace wall of the coking chamber.
As shown in (b) to (d), a gap is generated between the coke and the furnace wall due to the contraction of coke until the movement of the coke 1 starts, but the coke 1 itself contracts in the extrusion direction and is compacted. Then, it swells in a direction orthogonal to the extrusion direction and comes into contact with the carbonization chamber furnace wall surface 2 to be restrained. For this reason, as shown in FIG. 1A, the load waveform of the extrusion ram 3 continues to rise until the coke shrinkage phenomenon reaches the cork side end, as shown in FIG. It reaches a peak value and thereafter decreases. That is, the load applied to the extrusion ram 3 becomes a peak value due to the static friction at the time when the whole coke 1 contracts and the whole coke starts moving, and the static friction changes to the dynamic friction shown in FIG.
The load decreases due to the decrease in the extrusion amount.

However, when there is an abnormality in the furnace wall of the coking chamber,
As shown in FIG. 2A, the dynamic friction does not decrease to the normal level shown by the dashed line, and the coke 1 is overloaded until the coke 1 passes through the locally distorted portion 4 until FIG. )
When passing through the locally distorted portion 4 shown in FIG. The same applies to the case where the width of the coking chamber furnace is reduced due to the adhesion of carbon. If the coke passes through the portion where the furnace width of the coking chamber is reduced, the load is sharply reduced.

That is, the waveform of the load applied to the extrusion ram 3 indicates that an abnormal portion exists on the wall surface 2 of the carbonization chamber.
As shown in (a), since the overload occurs until the coke passes through the abnormal part, abnormal phenomena such as local distortion or carbon adhesion generated on the furnace wall of the coking chamber and abnormal positions in the furnace length direction are caused. Can be estimated.

As shown in FIG. 3, the abnormality in the coking chamber is estimated as shown in FIG. 3 when there is no abnormality (in a normal state). ) And its variation σ _A , and the extrusion waveform variation σ ′ during the extrusion movement are obtained as reference values. In the management of the variation σ _A , the management value of 3σ is usually set to a management value of 1σ and 2σ from the viewpoint of prevention of the extrusion trouble. First, it is determined that an abnormality has occurred after 3 days or more with (A- [sigma] _A ) as the threshold value for the pushing force decrease width. Further, even once it becomes less _(A-2σ A),
At that time, it is determined that an abnormality has occurred.

If it is determined from the load waveform applied to the extrusion ram that an abnormality has occurred, if the subsequent pushing force time lapse width is greater than the extrusion waveform variation σ ′, it is determined that an abnormal portion has passed, and an abnormal portion is detected from the extrusion port. The abnormal position is estimated by calculating the distance to the abnormal position.

If the abnormality is damage to the furnace wall, gas leaks from the damaged portion into the combustion chamber, and the incomplete combustion increases the CO concentration in the combustion exhaust gas. However, if the abnormality is carbon adhesion, gas leakage to the combustion chamber does not occur,
The CO concentration in the flue gas does not change. That is, by monitoring the CO concentration in the combustion exhaust gas, it is possible to distinguish whether the abnormality generated in the carbonization chamber is due to damage to the furnace wall brick or to carbon adhesion.

The concentration of CO in the flue gas is monitored by gas chromatographic analysis of the flue gas from the knee piece on the outlet side of the heat storage chamber, which leads to the withdrawal flue of the combustion chamber.
Calculate the concentration and use 2σ as the threshold value in the variation σ management,
If it exceeds 2σ, it is determined that the furnace wall is damaged (crack).

In addition, damage to the furnace wall brick and carbon adhesion
Since the progress usually proceeds gradually, abnormality can be detected early by checking the load waveform change and the CO concentration in the combustion exhaust gas, and damage can be minimized.

[0021]

【Example】

Example 1 Furnace height 6000 mm, furnace width 450 mm, furnace length 15560 m
m, an effective volume of 37.9 m ³ , in a coke oven consisting of 106 chambers, the relationship between the decrease width from the peak value of the pushing force waveform before and after the start of the entire coke movement applied to the extrusion ram and the abnormal ratio of the carbonization chamber furnace wall. The relationship was investigated. FIG. 4 shows the results. As shown in FIG. 4, the average value A of the decrease in the pushing force in the normal state is 7 Ton, and in this case, the abnormal furnace kiln presence ratio is 0%.
Met. Also, (average pressing force decrease width A during normal operation)-
In the case of (decrease width variation σA), the furnace wall abnormal kiln existence ratio is 20%, and in the case of (normal pushing force drop width average value A) − (decrease width variation 2σA), the furnace wall abnormal kiln existence ratio Was 90%. In addition, the CO concentration was measured by gas chromatographic analysis of the combustion exhaust gas at the knee piece on the outlet side of the heat storage chamber, which led to the flue of the combustion chamber on both sides of the carbonization chamber, and the relationship with the furnace wall damage (crack) kiln presence ratio. investigated. The result is shown in FIG. As shown in FIG. 5, the average value of the CO concentration in the combustion exhaust gas in a normal state was 0.5%, and in that case, the rate of presence of the furnace wall damaged kiln was 0%. When the CO concentration was equal to or more than (average CO concentration at normal time) + (variation of concentration fluctuation 2σ), the furnace wall damaged kiln ratio was 80%. Therefore, when the pushing force falls below (A-2 [sigma] _A ) and when the CO concentration in the combustion exhaust gas becomes lower than (C at normal time).
By performing control when the temperature rises to more than (O concentration average value) + (CO concentration variation 2σ), the presence and abnormal position of the furnace wall in the coking chamber and whether the furnace wall abnormality is due to furnace wall damage or carbon adhesion Can be determined. Here, also for the number of consecutive days when _(A-1σ A) drops below, if continued for more than 3 days, and chamber wall abnormality is confirmed to the value about the same _(A-2σ A).

Example 2 Based on the above values, furnace height 5000 mm, furnace width 450 mm, furnace length 14620 m
m, effective volume 29.3 m ³ 168 rooms and furnace height 6
In a coke factory consisting of 106 kilns having a furnace size of 000 mm, a furnace width of 450 mm, a furnace length of 15560 mm and an effective volume of 37.9 m ³ , as shown in FIG. The fall width from the peak value of the waveform is calculated, and days lower than the value of (average value A of the fall width from the peak value at normal time) − (1σ _A ) continue for 3 or more days, or (peak value at normal time) If a value equal to or less than the average value A) − (2σA) of the drop width from the sample is determined to be abnormal, the distance from the kiln mouth to the abnormal part is calculated from the differential value (change width) of the pushing force, Gas chromatographic analysis of the combustion exhaust gas at the knee piece on the outlet side of the heat storage chamber leading to the withdrawal flue of the combustion chamber on the side of the carbonization chamber is performed by gas chromatography.
Measure the concentration, and if the CO concentration increases by 2 σ or more from the previous day or the CO concentration is 2 σ or more
Judge that there is a risk of furnace wall damage, take repair measures for the damaged part of the furnace wall, and if the CO concentration is 2σ or less from the previous day or the CO concentration is 2σ Changes in the number of extrusion troubles and occurrences of detention in the years before and after the adoption of the method of the present invention to determine and perform carbon burn-off, changes in coke tumbler strength, charged coal volatiles (VM%), and coke dry heat Is shown in FIG. Note that the coke dry heat was calculated by using a load factor of 95.
%, Water 9.1%.

As shown in FIG. 7, extrusion trouble occurred at a considerable frequency until 1999 before adopting the method of the present invention, but after 1990 when the method of the present invention began to be employed,
Almost no extrusion troubles occurred, and in particular during the last three years of strengthening management, although there was a slight stoppage, it was resolved by re-extrusion, and zero extrusion troubles continue.

[0024]

The method for detecting abnormalities in a coke oven carbonization chamber at an early stage according to the present invention distinguishes between damage to a furnace wall brick in a coke oven and generation of attached carbon, which are the main causes of extrusion troubles that hinder the productivity of a coke oven. In addition, it is possible to prevent the extrusion trouble beforehand and to prevent the coke oven carbonization chamber from progressing due to the extrusion trouble by detecting it early and taking measures while identifying the location of the occurrence. Furnace life can be extended.

[Brief description of the drawings]

FIG. 1 is an image diagram of a change in pushing force and the behavior of a coke mass during normal extrusion, wherein FIG. 1 (a) is a graph showing the relationship between the time elapsed from extrusion and the pushing force, and FIG. 1 (b) is a coke mass before extrusion. (C) is a plan view of the coke mass immediately after the start of coke extrusion, (d) is a plan view of the coke mass at the completion of coke shrinkage, and (e) is a diagram of only the dynamic friction during the extrusion. It is a top view of a coke lump.

FIGS. 2A and 2B are image diagrams of the change of the pushing force and the behavior of the coke mass when the carbonization chamber furnace wall is abnormal. FIG. 2A is a graph showing the relationship between the elapsed time from the extrusion and the pushing force, and FIG. (C) is a plan view of the coke mass at the time of completion of coke shrinkage, (d) is a plan view of the dynamic coke mass due to local strain, and (e) is a local strain portion. FIG. 3 is a plan view of a coke lump after kinetic friction has been reduced to a normal level after passing through.

FIG. 3 is a graph showing a relationship between an elapsed time from extrusion and a pushing force for explaining a damage estimation method.

FIG. 4 is a graph showing the relationship between the pushing force reduction width A and the abnormal ratio of the furnace wall of the coking chamber.

FIG. 5 is a graph showing the relationship between the CO concentration increase width and the carbonization chamber furnace wall damage ratio when the carbonization chamber furnace wall is abnormal.

FIG. 6 is a system diagram showing an example of damage estimation thinking of the present invention.

FIG. 7 is a graph showing the transition of the number of extrusion troubles and the number of occurrences of detention, the transition of the coke tumbler strength, the transition of the charged coal volatile matter, and the transition of the coke dry carbonization heat for several years before and after the method of the present invention was adopted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coke 2 Furnace wall 3 Extrusion ram 4 Local distortion part

Continuation of the front page (56) References JP-A-8-225787 (JP, A) JP-A-8-53676 (JP, A) JP-A-3-146589 (JP, A) JP-A-63-83193 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C10B 29/06 C10B 33/08 C10B 41/04

Claims (1)

(57) [Claims] When extruding coke from a coke oven carbonization chamber, the presence or absence of an abnormality and an abnormal site are detected from a load waveform applied to an extrusion ram of an extruder, and a combustion chamber adjacent to the carbonization chamber is withdrawn. At the knee piece on the outlet side of the heat storage chamber that leads to the flue, it is determined whether the abnormal carbonization chamber is due to damage to the furnace wall bricks or to the carbon deposits based on the CO concentration obtained by analyzing the combustion exhaust gas during coal charging. Abnormal early detection method of a coke oven carbonization chamber.