JP2008214379A - Method for operating chamber type coke oven - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which pushing force can accurately be estimated in pushing of coke in a chamber type coke oven. <P>SOLUTION: The method for operating the chamber type coke oven is carried out as follows: the pushing force required when discharging the coke from a carbonization chamber of the chamber type coke oven with a pusher is estimated by using the amount of gap (clearance) between the oven wall and the coke produced during coal carbonization and the pushing of the coke is performed on the basis of the pushing force. In the method, the amount of gap is determined by considering the extent of deformation of the oven wall of the carbonization chamber during the coal carbonation. The extent of the deformation of the oven wall produced during the coal carbonization is estimated from the vertical crack width of oven wall bricks and the swelling pressure of the coal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for discharging coke obtained by dry distillation of coal in a carbonization chamber at an appropriate load from the carbonization chamber to enable stable operation of the coke oven.

  Extruding coke after carbonization with low load is very important from the viewpoint of not only stabilizing the operation and securing the amount of wreckage, but also reducing the load on the furnace wall of the carbonization chamber and extending the furnace life. is there. The resistance at the time of discharging coke from the carbonization chamber is caused by a reaction force generated by friction between the coke and the bottom of the furnace or between the coke and the furnace wall. In order to reduce this reaction force, generally, measures such as smoothing the furnace wall surface and furnace bottom, or increasing the amount of gap between the furnace wall and coke (hereinafter also referred to as clearance) are effective. ing. Here, the clearance depends on the horizontal burn-out amount of the coke, and the horizontal burn-out amount depends on the coal properties (volatile matter, etc.) and the operating conditions of the coke oven (furnace temperature, setting time, etc.).

Many methods for stabilizing the operation of the coke oven have been proposed focusing on the above clearance.
For example, in Patent Document 1, a horizontal burn-out amount corresponding to a control value of the coke cake required extrusion pressure is calculated from the relationship between the horizontal burn-out amount and the coke cake required extrusion pressure, and the carbonization time and the horizontal firing in a test furnace are calculated in advance. A method is described in which, by determining the relationship with the amount of reduction, in the chamber coke oven, the carbonization time at which the amount of horizontal burning is the control value is set as the lower limit value.
Moreover, in patent document 2, when the furnace wall damage has not occurred, the furnace wall surface temperature, the coal properties, the coke oven operation rate, the number of days of kiln repair, and the amount of coal charged into the coke oven are used as parameters. A method is described in which an extrusion force is estimated by linear linear combination and a damage state of a furnace wall is estimated based on a difference between the estimated extrusion force and an actually measured extrusion force.

Further, in Patent Document 3, the extrusion load is estimated from conditions such as the expansion pressure of the blended coal, the moisture content, the setting time of the dry distillation coke, the furnace temperature of the coke oven, and the estimated extrusion load estimated value is set in advance. An operation method for adjusting the above-described conditions so as to be within the range of the control value has been proposed.
Moreover, in patent document 4, the numerical value of the database which consists of the operation data created for every carbonization chamber, coal blend data, coke data, repair data, and damage data is statistically processed, and multiple regression analysis is performed as multiple variables, and coke extrusion is performed. A method for calculating the force for each carbonization chamber has been disclosed, and a furnace body diagnosis system that predicts the possibility of furnace wall brick breaking based on the pushing force obtained by this calculation has been proposed.

Moreover, in patent document 5, the carbon resistance index calculated | required from the furnace wall carbon amount estimated from coal properties and the furnace operating condition and the furnace top space carbon amount is defined, and this carbon resistance index and the ram drive motor of the extruder are applied. A method is disclosed in which the load applied during extrusion is estimated from the correspondence with the load, the load is reduced by adjusting the coal properties or operating conditions, and clogging is prevented.
Moreover, in patent document 6, while calculating | requiring the load waveform at the time of coke extrusion based on the operating condition information of a coke oven, the property information of coal, and furnace body profile information by calculation, it compares with the load waveform measured at the time of extrusion. Discloses a method for analyzing the operating conditions of a coke oven.

Further, in Patent Document 7, a transmission radiation image in the furnace width direction of coke produced in a test coke oven is taken, and the extrudability of the coke cake is estimated based on the shrinkage amount and crack amount of the coke cake obtained from the transmission radiation image. A method is disclosed.
Moreover, in patent document 8, extrusion force is estimated using the width direction expansibility index | exponent of a coke cake, the amount of gaps between a coke cake side surface, and a furnace wall inner surface, so that this estimated extrusion force may become below an allowable limit value. A method of operating a coke oven that adjusts coal properties, coal blending ratio, and furnace operating conditions is disclosed.
Further, in Patent Document 9, a step of determining whether or not coke can be extruded in the carbonization chamber, an extrusion force estimation step of estimating coke extrusion force when it is determined that extrusion is possible, and extrusion based on the estimated extrusion force are performed. An operation program for a coke oven having an instruction for instructing extrusion has been proposed, and the extrusion force is calculated based on the value of the nearest pushing force in the carbonization chamber, the elapsed time after charging the coal, the average pushing force of the furnace group, A method of estimating data such as coal amount and combustion chamber temperature by performing multiple regression analysis is disclosed.

In addition, in connection with these techniques, as a method for obtaining the shrinkage rate of coke, that is, horizontal burning, Patent Document 10 includes heating coal to a temperature T (° C.) equal to or higher than a resolidification temperature, A method for obtaining the coke shrinkage based on the difference in volume or length between the resolidification temperature and the temperature T, or in Patent Document 11, the reflectance distribution and the blending ratio of the vitrinite structure of simple coal is blended. The method of estimating the reflectance distribution of the vitrinite structure of charcoal and estimating the coke shrinkage of the blended coal, or Patent Document 12, includes dry-blending the blended coal in a double-sided heating type test coke oven, A method for measuring the change with time has been proposed.
Further, as a method for estimating the coal expansion pressure, Patent Document 13 discloses a gas permeability coefficient based on a method of measuring a gas permeability coefficient of a coal bed in a softened and melted state, or estimating from a coal property or dry distillation conditions. And estimating the change over time in the coal expansion pressure using the gas permeability coefficient, the thickness in the furnace width direction of the coal layer in the softened and melted state, and the generation rate of the pyrolysis gas from the softened and melted layer, Patent Documents 14 and 15 propose a method of calculating the expansion pressure of coal blend from the additive average value of the maximum expansion pressure of each coal constituting the coal blend, the blending ratio of non-slightly caking coal, and the like.

JP-A-8-283730 Japanese Patent Application Laid-Open No. 11-131069 JP 2000-73067 A JP 2002-121556 A JP 2002-173687 A JP 2003-277759 A JP 2005-68296 A JP 2005-350610 A JP 2005-307168 A JP-A-2005-232349 JP 2006-249174 A Japanese Patent No. 3254004 Japanese Patent No. 3142737 JP-A-11-302661 JP 2001-214171 A

In the above method, when estimating the coke extrusion force from the coke oven, the properties of the coal, the operating conditions of the coke oven, the damaged state of the furnace wall, etc. are taken into consideration, and the coke oven is managed in any case. Important information is used, and it is considered that a highly accurate estimated value can be obtained.
However, as described in Japanese Patent Application No. 2006-297274 filed earlier by the applicant, the furnace wall of the coking furnace is displaced in the furnace width direction with time. This suggests that it is necessary to take this wall displacement into account when estimating the coke extrusion force. However, the above application does not disclose how this wall displacement should be taken into account in the estimation of the pushing force.
As described above, increasing the clearance (gap amount) between the furnace wall and coke is effective for reducing the coke extrusion force from the chamber coke oven. To estimate this clearance, In addition to the amount of carbon thickness generated on the surface of the furnace wall bricks by pyrolysis of the dry distillation product gas, the furnace wall displacement due to expansion pressure accompanying melt softening of coal and horizontal burning due to coke shrinkage The amount must be taken into account.
However, although estimation formulas that incorporate coal expansion pressure, coke shrinkage, and carbon thickness have been proposed in the past, the amount of furnace wall displacement has not been properly considered, and in an actual coke oven, Due to the displacement, the amount of gap between the furnace wall and coke could not be estimated accurately.
The present invention provides a method for accurately determining the amount of gap between the furnace wall and coke by appropriately considering the amount of displacement of the furnace wall, and based on this, the necessary extrusion force is estimated and the proper extrusion force is obtained. This makes it possible to extrude coke.

The inventors measured the displacement of the furnace wall due to the coal expansion pressure generated during coal carbonization in an actual coke oven, and determined the amount of gap between the furnace wall and coke determined in consideration of the amount of displacement of the furnace wall. The inventors have found that the extrusion force shows a good correspondence, and have completed the present invention.
That is, the gist of the present invention is as follows.
(1) Estimate the pushing force required to discharge coke from the coking chamber of a chamber coke oven using an extruder using the gap between the furnace wall and coke generated during coal dry distillation, and based on this extrusion force A method for operating a coke oven, wherein the amount of the gap is determined in consideration of the amount of displacement of the furnace wall of the carbonization chamber.
(2) The method of operating a coke oven according to (1), wherein a displacement amount of the furnace wall generated during the carbonization is estimated from a vertical crack width of the furnace wall brick and an expansion pressure of the coal. .
(3) The operation of the chamber coke oven according to (2), wherein the width of the vertical crack of the furnace wall brick is obtained from the amount of expansion of the furnace body in the furnace length direction of the furnace and the number of vertical cracks. Method.
(4) As described in (2) or (3), the coal expansion pressure for estimating the amount of displacement of the furnace wall is the coal expansion pressure of the carbonization chamber and the adjacent carbonization chamber on both sides thereof. How to operate a room type coke oven.

  According to the present invention, the amount of displacement of the furnace wall in consideration of the blending conditions of the coal (hereinafter also referred to as charging coal), the operating conditions of the coke oven, the operating years of the furnace body, etc. The coke extrusion force can be estimated easily and accurately using the clearance between the furnace wall and coke determined in consideration of the coke, and the coke can be extruded with an appropriate extrusion force. Became possible.

  In estimating the extrusion force in consideration of the displacement of the coke oven wall, the actual state of the displacement of the furnace wall was investigated by tests. The inventors charged coal into the carbonization chamber (hereinafter also referred to as the carbonization chamber, the kiln or the self-fired kiln) and made the adjacent carbonization chamber (hereinafter also referred to as the adjacent kiln) an empty room. A furnace wall displacement measuring device, which will be described later, is arranged to heat and distill the coal in the carbonization chamber charged with coal, and the displacement of the furnace wall in this carbonization chamber is measured by the displacement of the furnace wall in the adjacent carbonization chamber. did. Since this adjacent kiln is vacant, the displacement amount of the furnace wall of the kiln to be measured can be regarded as equivalent to the displacement amount of the furnace wall of the adjacent kiln. Gas pressure measuring device from the furnace lid in the coal bed of the kiln (consisting of a metal thin tube inserted into the coal bed of the carbonization chamber, a pressure indicator, a thin tube connecting them, and a recording device) and A temperature measuring device (thermocouple) was inserted, the gas pressure in the softened and molten layer of the charged coal was measured as the coal expansion pressure, and the temperature of the charged coal layer in the carbonization chamber was measured.

Here, a furnace wall displacement measuring apparatus will be described. FIG. 8 is a schematic cross-sectional view in the furnace width direction of the coke oven showing a state in which the displacement measuring device is disposed in the carbonization chamber.
The carbonization chambers 1a and 1b are provided on both sides in the furnace width direction with the combustion chamber 2 therebetween, and are partitioned by a furnace wall 3, and the furnace wall is formed by combustion of fuel gas supplied from the gas port 4 of the combustion chamber 2. Then, the coal 5 charged into the carbonization chamber 1a is dry-distilled to form a coke cake 6. The carbonization chamber 1b is not filled with coal and is empty, and a furnace wall displacement measuring device 7 is disposed in the chamber.
The furnace wall displacement measuring device 7 is inserted into the furnace through a support plate 9 disposed so as to cover the charging port 8 at the top of the coking chamber 1b of the coke oven, and through an opening 10 of the support plate 9. A water-cooled metal probe 11 having a lower end portion bent toward the surface of the wall 3, and can swing in the furnace width direction with the lower end portion of the metal probe 11 in contact with the furnace wall 3. In this manner, the upper end portion of the metal probe 11 is suspended and supported, and the probe support portion 12 is fixed to the support plate 9, and the tilt amount detector 13 is used to measure the tilt amount of the probe. The probe support portion 12 is fixed to the upper end portion of the metal probe 11, a holding metal fitting (not shown) having a knife edge in the furnace width direction at the other end, and fixed to the support plate 9, the knife edge of this holding metal fitting And a rocking bearing (not shown) having a V-shaped groove for supporting the metal probe in a line contact manner in the furnace width direction, and pivotally supporting the metal probe. The probe tilt amount detector 13 is a non-contact made up of a laser oscillator 14 fixed to the upper end of the metal probe 11 and a light receiving plate 15 provided at the top of the furnace spaced from the laser oscillator 14 in the furnace width direction. It is a type detector.

  A water-cooled metal probe 11 is inserted into the furnace from the inlet 8 and its lower end is brought into contact with the furnace wall surface 3 for measuring displacement. When this probe is tilted in the furnace width direction following the furnace wall displacement, by reading the position change of the light spot on the light receiving plate of the laser beam 17 by the probe tilt amount detector, that is, by tilting the laser oscillator, From the geometric relationship in these optical systems, the inclination angle of the metal probe can be obtained, and the amount of displacement of the furnace wall can be obtained (see Japanese Patent Application No. 2006-297274).

As a measurement result of the investigation, FIG. 7A shows the furnace wall displacement of the kiln (measured in the adjacent kiln as described above), and FIG. 7B shows the furnace width direction center of the kiln (carbonization chamber). The change of the temperature of the coal bed measured in the same position as the measurement of the coal expansion pressure and the coal expansion pressure measured in the section (hereinafter also referred to as the temperature in the coal) is shown with respect to the elapsed time after charging the coal. As can be seen from (a) of FIG. 7, the furnace wall is greatly displaced toward the expansion side (the direction of the adjacent kiln) immediately after the coal is charged, but it becomes smaller with the passage of time and is almost restored to the original state. I know that.
That is, the furnace wall is displaced to the expansion side immediately after charging the coal. This is due to the temporary expansion of the furnace wall due to the powder pressure of coal and the rapid temperature drop of the furnace wall brick surface. Conceivable. In addition, when the temperature in the coal is less than 400 ° C, no significant change is observed in the gas pressure, but when the temperature in the coal reaches 400 to 500 ° C after 8 to 10 hours after charging, the furnace width The coal expansion pressure at the center in the direction increases rapidly, and the furnace wall is greatly displaced toward the expansion side. After that, although the coal expansion pressure has decreased, the displacement of the furnace wall has also decreased in synchronization with this, and it has returned to a state almost close to the original position. This large displacement of the furnace wall is considered to be due to the pressure (coal expansion pressure) caused by the gas generated while the coal is softening and melting. Considering that the clearance between the furnace wall and coke is about a few millimeters, the furnace wall displacement immediately after charging the coal into the carbonization chamber and the furnace wall displacement due to the coal expansion pressure are never negligible. I understand.

The inventors have conceived that the displacement of the furnace wall due to the coal expansion pressure described above greatly affects the formation of clearance, which is an important factor in estimating the coke extrusion force, and a clearance formation model that reflects the displacement of the furnace wall. Was assumed. FIG. 1 is a schematic diagram for explaining the behavior of the furnace wall and coke in the coal carbonization process, and explains the clearance formation considering the displacement of the furnace wall.
FIG. 1 also shows a conventional case that does not consider the displacement of the furnace wall. Hereinafter, this model will be described.

  1) During coal charging: As mentioned above, the furnace wall may be temporarily displaced to the expansion side due to the powder pressure during coal charging or the rapid temperature drop of the brick surface. As the temperature of the furnace wall brick recovers, the temperature decreases and returns to the original position. This is the origin of the furnace wall position.

  2) Furnace wall displacement due to coal expansion pressure: Coal is heated to high temperature sequentially from the side in contact with the furnace wall and softened and melted, then re-solidified into coke, but the softened and melted state is very viscous. The gas generated from is present in the form of bubbles in the softened molten layer. The pressure of the gas in the bubbles exerts a force on the furnace wall through coke (solid) generated between the softened molten layer and the furnace wall, and displaces the furnace wall. The softened molten layer progresses from the both furnace wall sides of the carbonization chamber toward the center in the furnace width direction, and finally reaches the peak in the stage where the coal expansion pressure meets at the center in the furnace width direction (hereinafter also referred to as the maximum expansion pressure). At this time, the furnace wall is expanded and displaced to the maximum position together with the coke. This displacement is defined as a furnace wall expansion displacement amount B.

3) Subsequent to softening and melting, coking (re-solidification) proceeds, and so-called burn-out occurs in which the volume of the coke is reduced due to separation of volatile components, condensation polymerization reaction, and the like. Although this burning occurs three-dimensionally, a clearance L is formed between the furnace wall and the coke by the horizontal burning (hereinafter also referred to as horizontal burning). Let this horizontal burn-out amount be A.
The horizontal burn-out amount A depends on the properties of the charged coal, the dry distillation conditions, etc., but if these conditions are constant, it is a constant amount.
By the way, since the coal expansion pressure disappears when all the charged coal is coke, it is considered that the furnace wall that has been expanded and displaced by the coal expansion pressure returns to the original position.
Further, the horizontal burning of the coke is started from the position of the furnace wall in the above 2), that is, the position of the furnace wall when the coal expansion pressure becomes maximum, so that the furnace wall expansion displacement amount B is set to the original furnace wall. When considering the position, the formed clearance L1 is L1 = A−B.

4) As described above, it was found that the furnace wall was greatly expanded and displaced by the coal expansion pressure, but the same occurred in the adjacent carbonization chamber (adjacent kiln). It is important to consider not only the displacement of the furnace wall but also the influence of the displacement of the furnace wall of the carbonization chamber (adjacent kiln) adjacent to this carbonization chamber.
The expansion displacement amount of the furnace wall of the adjacent kiln varies depending on the properties of the coal charged in the adjacent kiln, operating conditions, etc., but can be grasped according to those conditions.
The amount of displacement of the furnace wall of the own furnace due to the expansion displacement of the furnace wall of the adjacent furnace is C (the direction toward the own furnace is positive), and the furnace wall displacement C of the adjacent furnace is the original The clearance L2 when considering the furnace wall position is L2 = A-B-C.

  As apparent from the case where the displacement of the conventional furnace wall in FIG. 1 is not taken into consideration, in the present invention, the horizontal direction of the coke is determined when obtaining the clearance, which is the most important factor in estimating the pushing force. Based on the clearance obtained in consideration of i) expansion displacement amount B due to coal expansion pressure and / or ii) furnace wall displacement amount C of the own furnace due to expansion displacement of the adjacent kiln. Thus, the extrusion force is estimated.

Needless to say, when the clearances L1 and L2 are obtained, the thickness of the deposited carbon formed on the furnace wall or the influence of the unevenness of the furnace wall can be taken into consideration by a known method.
For example, if the thickness of carbon deposited on the furnace wall is D (not shown), and L3 is a clearance considering this, L3 = ABCD.

The amount of quenching A is, for example, disclosed in Patent Documents 10 to 12 in consideration of conditions such as the properties of the coal charged into the carbonization chamber (for example, the content of volatile components) and the carbonization conditions (for example, carbonization temperature). It can be determined by the method described.
On the other hand, the expansion displacement amount B of the furnace wall and the furnace wall displacement amount C of the carbonization chamber (own kiln) due to the expansion displacement of the adjacent carbonization chamber (adjacent kiln) are charged using the furnace wall displacement measuring device described above. Depending on the properties of the coal to be used and the operating conditions of the furnace, it may be obtained each time, but the inventors further examined a method for obtaining these more efficiently.

First, the displacement amount B of the furnace wall of the carbonization chamber (own kiln) will be described.
The inventors use the furnace wall displacement measuring device described above, and in accordance with the properties of the coal charged into the carbonization chamber and the state of the furnace, the gas pressure at the maximum expansion, the furnace wall displacement amount at that time, The relationship was investigated. The displacement of the furnace wall is affected by the condition of the furnace wall in the coking chamber (degree of aging), such as the presence or absence of cracks in the furnace wall, the degree of cracks (width of longitudinal cracks), and the degree of repair of furnace wall bricks. In consideration of the above, three coke chambers (kilns) of X, Y, and Z in different coke chamber conditions were investigated in a coke oven that actually produces coke. Here, the X kiln is a kiln that has only been repaired locally, that is, an old kiln, the Z kiln is a kiln (renewed kiln) that has been completely repaired by reloading the furnace wall bricks of the carbonization chamber, and the Y kiln is these It is a kiln that has been repaired to a middle level.
Moreover, according to the method disclosed by patent documents 13-15, the charging coal from which a maximum expansion pressure differs was prepared, these were charged into the carbonization chamber, and dry distillation was performed. And the displacement of the furnace wall of each carbonization chamber was measured by the furnace wall displacement measuring apparatus by the same method as the above, and the maximum expansion pressure of coal was measured by the gas pressure measuring apparatus.

FIG. 2 shows the relationship between the actually measured maximum expansion pressure (kPa) of coal and the furnace wall displacement (mm). As can be seen from the relationship in FIG. 2, the amount of displacement of the furnace wall increases almost in proportion to the maximum expansion pressure, and the inclination, that is, the rate of change of the furnace wall displacement amount of the carbonization chamber with respect to the maximum expansion pressure ( mm / kPa) is much larger in the X kiln (aged kiln) than in the Z kiln (renewal kiln). This is considered to be because the proof stress against the horizontal load is reduced due to a large vertical crack remaining on the furnace wall of the carbonization chamber in the X kiln.
For this reason, the amount of displacement of the furnace wall of the carbonization chamber can be determined based on the relationship with the maximum expansion pressure of coal generated in the carbonization chamber.
In this case, the relationship between the maximum expansion pressure of coal and the amount of displacement of the furnace wall may be obtained for each carbonization chamber, or each carbonization chamber is subjected to the status of the furnace wall (degree of aging), for example, cracks in the furnace wall bricks. The number of cracks, crack width, length, etc. are ranked as factors, and for each rank, the relationship between the amount of furnace wall displacement and maximum expansion pressure as shown in Fig. 2 is obtained. Then, the amount of displacement of the furnace wall may be obtained.

In order to more efficiently determine the amount of displacement of the furnace wall due to the maximum expansion pressure, the inventors focused on the width of the vertical crack in the furnace wall as an index representing the condition of the carbonization chamber, and the average width of the vertical crack in the furnace wall. And the relationship between the change rate of the furnace wall displacement and the above. That is, the average width of the longitudinal cracks is obtained by dividing the amount of expansion displacement in the furnace length direction (coke extrusion direction) of the furnace body by the number of longitudinal cracks existing on the furnace wall. The expansion amount of the furnace body in the furnace length direction was measured by a furnace body expansion measurement method (piano wire survey method). In other words, a standard piano wire is placed on each side of the coke oven extruder and guide wheel, and the distance from the piano wire to a specific position of the coke oven body is measured periodically when the coke oven is in operation (hot). The distance value obtained can be obtained from a comparison over time. Further, the number of vertical cracks was counted by visual observation from the inlet and the kiln opening at both ends of the carbonization chamber.
Table 1 shows the average width of the vertical cracks in the carbonization chamber of the above-described XZ furnace. As can be seen from Table 1, the average width of longitudinal cracks is large in the old kiln, which is 3.6 mm / bar in the X kiln (old kiln) and 0.29 mm / bar in the Z kiln (renewed kiln).

Table 1 also shows the rate of change (the rate of change of the furnace wall displacement) of the displacement amount of the furnace wall of the carbonization chamber of the XZ furnace obtained from FIG. 2 with respect to the maximum expansion pressure. Next, from these results, the relationship between the average width (mm) of the vertical cracks in the carbonization chamber and the rate of change of the furnace wall displacement (mm / kPa) was determined. The result is shown in FIG.
As can be seen from FIG. 3, the average width of the vertical cracks in the furnace wall (average vertical crack width) and the rate of change of the furnace wall displacement have a very clear proportional relationship. It can be expressed as
[Displacement rate of furnace wall displacement (mm / kPa)] = 0.144 [Average longitudinal crack width (mm)] + 0.102 ---- <1>
Here, as described above, the maximum expansion pressure can be estimated from the properties of coal charged in the carbonization chamber, the carbonization temperature, and the like, and the average width of longitudinal cracks is measured in advance by the above-described method. Can be obtained.
Therefore, it can be seen that the furnace wall displacement (mm) due to the maximum expansion pressure of coal can be obtained from the average vertical crack width (mm) of the furnace wall and the maximum expansion pressure (kPa) of coal in the carbonization chamber.

Next, the displacement amount C of the furnace wall of the carbonization chamber (own kiln) due to the displacement of the furnace wall of the adjacent carbonization chamber (adjacent kiln) will be described.
Since the displacement behavior of the furnace wall became clear, the influence of the adjacent kiln on the extrudability of coke was investigated next. That is, in the above displacement measurement test, the adjacent kiln was an empty kiln, so the extrusion load did not increase even when the coal expansion pressure of the charged coal was high. Therefore, charging coal having high expansion pressure (hereinafter also referred to as high expansion pressure coal) in the three adjacent carbonization chambers (N−1, N, N + 1) in which the furnace wall bricks of the carbonization chamber are completely replaced. And charging coal having a normal expansion pressure were charged in a combination as shown in Table 2, dry-distilled, and a test was conducted to investigate the relationship with the coke extrusion force. High expansion pressure coal has a maximum expansion pressure of about 20 times that of normal coal.
In addition, the maximum expansion pressure of coal charged in each carbonization chamber shown in Table 2 is estimated by the above-described method.

  In the test, in order to determine the influence of the coal expansion pressure of both adjacent kilns (N-1, N + 1) on the furnace wall displacement of the own kiln (N), first, coal is charged into the own kiln (N). Then, after about 8 hours, coal was charged into both adjacent kilns, and coke was extruded from the own kiln at the timing when the coal expansion pressure in both adjacent kilns became maximum. FIG. 4 is a diagram showing the timing (image) of coal charging and coke extrusion in the high expansion pressure coal charging test. The time change of the coal expansion pressure in each kiln is shown, and the charging of the coal into both kilns is delayed more than that of the own kiln (N). The timing is the maximum. And the maximum value of the electric current value of the ram drive motor of the extrusion apparatus at this time was measured and evaluated. The result is shown in FIG.

As can be seen from FIG. 5, when high expansion pressure coal is charged into the own kiln and both adjacent kilns (level 4), the current value during extrusion is the highest, but either one of the adjacent kilns is loaded with high expansion pressure coal. When entering (level 2) and when charging high expansion pressure coal only in its own kiln (level 3), compared to when normal coal is charged in its own kiln and both adjacent kilns (level 1), The current value during extrusion is about 7 to 10% higher.
In this way, it was confirmed that the displacement of the furnace wall due to the expansion pressure of the coal charged in the adjacent kiln has a great influence on the displacement of the furnace wall of the own kiln.

  About the furnace wall displacement amount C of this adjacent kiln, as in the case of the own kiln, as shown in FIG. 2, the relationship between the displacement amount of the furnace wall of the carbonization chamber and the coal expansion pressure, or shown in FIG. The relationship between the average longitudinal crack width of the carbonization chamber and the rate of change of the furnace wall displacement amount, that is, the relationship of the above-described <1> equation can be used.

In the above-described method, considering the expansion displacement amount B of the carbonization chamber furnace wall and / or the carbonization chamber displacement amount C due to the expansion displacement of the adjacent carbonization chamber furnace wall, between the furnace wall and the coke. The clearance can be obtained.
Based on this clearance, the extrusion force at the time of coke extrusion can be estimated by a known method, for example, the method described in Patent Document 1, 7, 8, or 12 or the like.
By the way, about the displacement amount B of the furnace wall demonstrated so far, the influence of the expansion behavior of the adjacent kiln on the displacement amount B is not considered. However, as shown in FIG. 4, when the expansion pressure of coal is maximum in the own kiln, since the expansion pressure of coal is generated in the adjacent kiln, the actual amount of displacement of the furnace wall in the own kiln is These are determined by the difference between the expansion pressure of the own kiln and the expansion pressure of the adjacent kiln.
Here, when the expansion pressure of coal in the own kiln becomes the maximum, how much expansion pressure is generated in the adjacent kiln may be measured by the gas pressure measuring device described above in the adjacent kiln, It is not realistic to measure the expansion pressure at every charge. For example, by the method disclosed in Patent Document 13, the gas permeability coefficient of a coal bed in a softened and melted state is determined as a coal property (in the coal structure). Inactive component amount and maximum fluidity) or a relationship diagram for estimation from dry distillation conditions is obtained in advance, the gas permeability coefficient is estimated from this diagram, and the gas permeability coefficient and coal in the softened and molten state It is realistic to estimate the change over time in the expansion pressure during the coal dry distillation process from the thickness of the layer in the furnace width direction and the rate of generation of pyrolysis gas per unit volume from the coal bed.

Hereinafter, the present invention will be described in more detail with reference to examples.
Table 2 shows normal coal and high expansion pressure coal in the carbonization chambers (N-1, N, N + 1) of three consecutive carbonization chambers (renewal kilns) in which the furnace wall bricks of the carbonization chamber are completely transposed. Charged in combination at such 4 levels, dry distillation was performed. Coke was extruded after dry distillation, and the maximum current value of the ram drive motor of the extrusion apparatus at that time was measured. In addition, as shown in FIG. 4, the carbonization chamber of both adjacent kilns reaches the maximum expansion gas pressure as shown in FIG. 4 when the timing of coal charging, the carbonization conditions, etc. are adjusted and the coke of the kiln is extruded after the carbonization. To be at that point.
The coke horizontal burn-off amount A is a dry-cooking of the blended coal for coke oven charging using the double-sided heating type test coke oven capable of measuring horizontal burn-out described in Japanese Patent No. 3254004 under the same conditions as the actual furnace. The change over time in horizontal burning during dry distillation was measured continuously.

As described above, the displacement amount B of the furnace wall was obtained from the average vertical crack width of the furnace wall of the kiln and the coal expansion pressure obtained from the properties of the charged coal according to the formula <1>. In addition, when the average vertical crack width of the furnace wall was measured by the method using the above-mentioned piano wire, it was 0.29 mm / piece. Moreover, the expansion pressure of coal was calculated | required by the method disclosed in the above-mentioned patent document 13.
Furthermore, as shown in FIG. 4, when the coal expansion pressure reaches the maximum in the kiln, the expansion pressure is also generated in the adjacent kiln, and accordingly, the amount of displacement of the furnace wall due to the expansion pressure of the own kiln. Will be offset. Therefore, the coal expansion pressure of the adjacent kiln at the time when the expansion pressure of the own kiln becomes maximum is assumed to be 70% of the maximum expansion pressure of the coal charged in the adjacent kiln. That is, the furnace wall expansion displacement amount B was obtained by the following formula <2>.
B = (maximum expansion pressure of own kiln−0.7 × maximum expansion pressure of adjacent kiln)
× (0.144 × average longitudinal crack width + 0.102) ----- <2>

Further, as described above, the displacement amount C is the maximum expansion pressure estimated based on the method disclosed in Patent Document 13 from the properties of the coal charged in the adjacent kiln and the average of the furnace wall. Based on the longitudinal crack width (0.29 mm / piece), it was determined by the formula <1>. In addition, as shown in FIG. 4, when the coal expansion pressure of the adjacent kiln becomes maximum, the expansion pressure of the own kiln disappears, so the offset term used in the <2> formula is considered. There is no need.
Further, the thickness of the deposited carbon generated between the furnace wall and the coke was calculated according to the method disclosed in Patent Document 5.
These results are shown in Table 3. In Table 3, when the furnace wall displacement is not considered (horizontal burnout A), when the furnace wall displacement of the own kiln is considered (L1), when considering the furnace wall displacement due to the own kiln and the adjacent kiln (L2), And the clearance when the thickness of the deposited carbon is taken into account (L3). Moreover, the relationship between the extrusion current value (maximum value) and the clearance in each case of Table 3 is shown in FIG.

From the results in Table 3 and FIG. 6, compared to the case where the furnace wall displacement is not taken into account (Δ in FIG. 6), or the case where only the furnace wall displacement of the own furnace is taken into account (FIG. 6 ◇), When the furnace wall displacement due to (Fig. 6 in Fig. 6) is considered, or when the thickness of the deposited carbon on the furnace wall is further taken into account in addition to the furnace wall displacement due to the own and adjacent kilns (● in Fig. 6) It can be seen that the relationship with the maximum current value is more clear.
That is, by considering the displacement of the furnace wall, the clearance can be more appropriately evaluated in a form close to the actual furnace condition, and the pushing force can be estimated with high accuracy.
Accordingly, it is possible to set an appropriate extrusion force at the time of coke extrusion, and it is possible to control coal blending conditions and coke oven operating conditions so as to achieve an appropriate extrusion force.

It is a schematic diagram explaining the behavior of a furnace wall and coke in a coal carbonization process. It is a figure which shows the relationship between the coal expansion pressure at the time of coal dry distillation, and a furnace wall displacement. It is a figure which shows the relationship between the average longitudinal crack width of a furnace wall, and the change rate of a furnace wall displacement amount. It is a figure which shows the timing (image) of the charging of coal and coke extrusion in a high expansion power coal charging test. It is a figure which shows the maximum electric current value of the extrusion apparatus at the time of coke extrusion at the time of mix | blending high expansion pressure coal. It is a figure which shows the relationship between the clearance amount between a furnace wall and coke, and the maximum electric current value of the extrusion apparatus at the time of coke extrusion. It is a figure which shows the time change of the condition of the carbonization chamber in a coal carbonization process, (a) shows the displacement of the furnace wall of a carbonization chamber, (b) shows the change of the temperature of a coal bed, and a coal expansion pressure. It is a cross-sectional schematic diagram explaining the outline | summary and the use condition of the measuring apparatus of a furnace wall displacement amount.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Carbonization chamber 2 Combustion chamber 3 Furnace wall 4 Gas port 5 Coal 6 Coke cake 7 Measuring device of furnace wall displacement amount 8 Charging inlet (charging lid)
DESCRIPTION OF SYMBOLS 9 Support plate 10 Opening part 11 Metal probe 12 Probe support part 13 Tilt amount detector 14 Laser oscillator 15 Light receiving plate 16 Contact point of a furnace wall and a displacement measurement probe 17 Laser beam

Claims (4)

  The pushing force required to discharge coke from the coking chamber of the chamber coke oven with the extruder is estimated using the amount of gap between the furnace wall and coke generated during coal dry distillation, and based on this estimated extrusion force A method for operating a coke oven in a coke oven, wherein the amount of the gap is determined in consideration of the amount of displacement of the furnace wall of the carbonization chamber generated during coal carbonization.   The method of operating a coke oven according to claim 1, wherein the amount of displacement of the furnace wall that occurs during coal carbonization is estimated from the vertical crack width of the furnace wall brick and the expansion pressure of the coal.   The method for operating a coke oven according to claim 2, wherein the vertical crack width of the furnace wall brick is determined from the amount of expansion of the furnace body in the furnace length direction of the furnace and the number of vertical cracks.   The chamber coke oven according to claim 2 or 3, wherein the expansion pressure of the coal for estimating the displacement of the furnace wall is the expansion pressure of the carbonization chamber and the adjacent carbonization chamber. Operating method.

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