JP2014091764A - Method for repairing coke oven by partial replacement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for repairing a coke oven by partial replacement, in which an expansion absorption margin is made proper without using a ceramic board.SOLUTION: When bricks for forming a flue of a combustion chamber of the coke oven are repaired by replacement while leaving a ceiling part 1 as it is, the temperature of a carbonization chamber-side wall of the flue that is connected to the flue to be repaired and is not to be repaired, and the temperature of the opposed side to the wall of the flue to be repaired that is adjacent to the flue to be repaired is retained at the temperature equal to or higher than 400°C. In a horizontal-direction joint 3 of the brick to be replaced, used is mortal which has 30% or higher linear shrinkage rate under 0.1 MPa load and 100-800°C temperature range. The thickness and the number of layers of the mortar are set and the mortar is disposed so that the thickness of the mortar per one place of the joint is lower than the projection height of a convex dowel part of the brick. An amorphous refractory material having 5 MPa or higher bending strength after hardened and dried is used in a connection part of the remaining ceiling part 1 to a newly-replaced portion.

Description

  The present invention relates to a partial transshipment repair method for a chamber furnace type coke oven.

  The coke oven is a kiln furnace in which combustion chambers and carbonization chambers are alternately arranged, and the temperature of the high-temperature combustion chamber is transferred to the coal in the carbonization chamber through wall bricks to dry-distill the coal to produce coke. . Some have been used for more than 30 years since construction, and repaired defective parts. In particular, the wall of the carbonization chamber receives a thermal history due to rapid cooling during coal charging and subsequent temperature rise, and is damaged due to wear during coal charging and extrusion. Therefore, repairs are carried out according to the degree of damage to extend life.

  One of the repair methods is a method of partial transshipment. This is a method of transshipping and renewing bricks on damaged wall parts. At this time, a ceiling part and the wall part which is not transposed remain | survived, and the wall brick of a damaged part is transshipped, holding them at the comparatively high temperature of 400 degreeC or more. Since the ceiling part remains, it is necessary to absorb the expansion of the new transshipment part and not transmit it to the ceiling part.

  For this reason, for example, Patent Document 1 discloses a technique in which a contractible ceramic board is used as a part of a wall member in addition to silica brick and a combination of siliceous mortar and cushion mortar is used as a joint material. When the ceramic board is used for the wall portion, it is difficult to use the brick at this portion because the brick at this portion is generally provided with unevenness called a dowel portion.

  Moreover, even if it is going to be used for the old and new joints of the ceiling, it is difficult to use for the following reasons. One of them is the site where old and new joints are concentrated on construction errors caused by joint thickness errors and brick dimensional errors. The thickness of joints varies depending on the location, so processing to match them is necessary. This is because, or it is necessary to process bricks and increase / decrease the joint thickness on the way so that the joints have the same height. The other is that the old and new joint bricks in the ceiling are deformed bricks, and if the expansion is not uniform, a force acts in the direction of rotation, making it easier to overhang or drop off.

JP 09-316456 A

  As described above, the conventional techniques have the inconvenience that the construction efficiency is poor and the risk of overhang and dropping is large.

  In view of the above circumstances, the present invention provides a partial transshipment repair method for a coke oven that enhances construction efficiency and eliminates little or no risk of overhang and dropout by optimizing the expansion absorption margin without using a ceramic board. It is intended to provide.

  In order to solve the above-mentioned problem, the partial transshipment repair method for a coke oven of the present invention repairs bricks forming a part of the flue of the combustion chamber of the chamber-type coke oven by transshipment and repairing them while leaving the ceiling portion. The horizontal direction of the bricks to be transposed while maintaining the temperature of the wall on the coking chamber side of the flue remaining without repairing the flue to be fixed and the wall facing the wall to be repaired adjacent to the flue to be repaired at 400 ° C or higher Mortar with a linear shrinkage of 30% or more from 100 ° C to 800 ° C under a load of 0.1MP is used as the expansion and absorption allowance of brick, and the vertical assumed from the room temperature to the operating temperature of the mortar Setting the thickness and number of layers of the mortar so that the total amount of shrinkage in the direction is 50 to 95% of the total amount of expansion in the vertical direction assumed from the room temperature to the operation temperature of the brick, and Set the thickness of the mortar per place of the ground to be less than the protruding height of the convex dowel part of the brick, place the mortar, and at the connection part between the remaining ceiling part and the newly piled part, An indeterminate refractory material having a bending strength of 5 MPa or more after being cured and dried is used.

  In the partial transshipment repair method of the coke oven of the present invention, it is preferable that the mortar construction position is in the furnace wall brick pile part below the brick wall part one step below the brick having different areas of the upper and lower surfaces forming the ceiling part. .

  Moreover, in the partial transshipment repair method of the coke oven of the present invention, the vertical total shrinkage assumed from the room temperature to the operation temperature of the mortar is the total expansion amount assumed in the vertical direction from the room temperature to the operation temperature of the brick. The thickness and the number of layers of the mortar are preferably set so as to be 50 to 80%.

  According to the partial transshipment repair method of the coke oven of the present invention, by optimizing the expansion absorption allowance without using a ceramic board, the construction efficiency at the time of partial transshipment repair is improved and the risk of overhang and dropout is little or not. Can be eliminated.

It is a schematic diagram which shows the brick cross section of the wall part between flues of the combustion chamber of the Carlstil type coke oven as an example of a chamber type coke oven.

  One embodiment of the partial transshipment repair method for the chamber furnace coke oven of the present invention is applied to a Karl-Styl coke oven as an example of the chamber oven coke oven shown in FIG. In this way, partial transshipment repair of bricks is performed. Here, reference numeral 1 in the figure is a ceiling portion, 2 is a horizontal tunnel connecting flues arranged in the longitudinal direction of the combustion chamber, 3 is a joint between bricks, 4 is a convex dowel portion of the brick, and 5 is a remaining ceiling portion. The amorphous refractory filled in the connection part between the part (upper side in the figure) and the newly loaded part (lower side in the figure) is shown.

  That is, the present inventors arranged and examined the problems in partial transshipment in which the ceiling part was left. Failures can be broadly classified as follows: overhang of the flue carbonization chamber side of the flue that remains without being repaired continuously to the reloaded flue and the wall portion between the flues on the flue side to be repaired, and the wall near the boundary between the transferred flue portion and the remaining portion It was an overhang. The former was found to be due to the difference in thermal expansion at the time of temperature rise caused by the temperature difference from the inner part due to the temperature drop of the remaining wall at the time of transshipment. As a result of various studies, the temperature of the wall on the coking chamber side of the flue that remains without being repaired continuously to the flue to be repaired, and the temperature of the wall facing the wall to be repaired adjacent to the flue to be repaired is maintained at 400 ° C. or higher. As a result, it was found that this problem can be avoided.

  On the other hand, regarding the latter, the inventors first made an intensive study on the optimum expansion absorption allowance for expansion in the furnace top direction. As a result, it was found that if the expansion absorption allowance is less than 50% of the assumed expansion, the frequency of overhanging the furnace wall bricks and cracking of the ceiling bricks increases. Therefore, 50% is considered appropriate as the lower limit of the expansion absorption allowance. On the other hand, if the expansion absorption allowance is 100% or more of the assumed expansion amount, the pressing from the ceiling portion is not effective at all, and the wall portion is merely self-supporting, and the structure becomes weak. Therefore, considering the expansion error, the upper limit of the expansion absorption margin is considered to be 95%.

  More preferably, the designed expansion absorption margin is 50% to 80%. The amount of water in the mortar tends to increase due to the ease of construction, and when the amount of water increases, the shrinkage rate increases and the amount of expansion absorption is larger than expected. When the design expansion absorption allowance is 80% to 95%, there is a risk that the actual expansion absorption amount exceeds 100%, and strict moisture management is required.

  Next, mortar was examined. As described above, since the partial transshipment is performed hot, the mortar becomes 60 ° C. to 100 ° C. after the construction, and the water evaporates and shrinks accordingly. Therefore, in order to absorb the expansion during the temperature rise, the shrinkage rate in a dry state of 100 ° C. to 800 ° C. is important. If the shrinkage rate of the mortar in this temperature range is smaller than 30%, it is difficult to secure the expansion absorption allowance. In addition, since brickwork is performed between operations, it is about 1 to 3 steps to load until the mortar dries. If it is about this level, the load is small, so it hardly shrinks even when dried. Moreover, if it dries, intensity | strength will increase a little and the shrinkage | contraction between brickwork is a level which is satisfactory.

  However, a mortar with a shrinkage rate of 30% or more obtains a large shrinkage rate due to the inclusion of organic matter, etc., so that the strength after temperature rise is very weak, and in the case of a large structure such as a coke oven, the temperature distribution is poor. There is a possibility that the expansion becomes non-uniform due to uniformity or the like, which may cause overhang and dropout. Accordingly, among the transposed bricks, the bricks constituting the ceiling portion above the line BB in FIG. 1 are complicated in shape, such as partly wide, and the influence of uneven expansion is large. The risk of overhang and dropout is great.

  On the other hand, the furnace wall brick below the line A-A in FIG. 1 has substantially the same upper and lower surfaces, and the wall brick has a shape that causes a force to rotate the brick when the joint 3 contracts due to the expansion absorption of the brick. hard. Further, as described above, since there is a dowel, it was found that if the construction thickness of the mortar per joint is less than the protruding height of the convex dowel portion 4, the inclination of the brick can be ignored. Therefore, here, the construction position of the mortar is defined as the furnace wall brickwork below the AA line in FIG. Part. More preferably, the construction thickness of the mortar is 2/3 or less of the protruding height of the convex dowel portion 4.

  The old and new joints on the ceiling have no dowels and are complex in shape and are not suitable for using mortar with a high shrinkage rate. Since the height of the old and new joints of the ceiling portion varies depending on the location as described above, it is indefinite and needs to have strength to support the ceiling portion 1. The inventor collected the coke oven brick in use and investigated it in detail, and the bending strength was about 5 MPa. Therefore, it has been found that the joint can secure the same strength as the coke oven brick by constructing the irregular refractory 5 having a bending strength of 5 MPa or more.

  Table 1 below shows the results of laboratory experiments, and shows the effect of limiting the construction thickness of mortar with a high shrinkage rate. Two pieces of 100 mm x 100 mm (thickness 50 mm) bricks with a dowel of 15 mm height (H) cut out from an actual furnace wall brick of 230 mm x 100 mm (thickness 160 mm), and 50 sheets in between. The mortar that shrinks in% is applied with the thickness (T) shown in Table 1, and the temperature is raised to 800 ° C. with 0.1 MPa loaded, and the ratio between the maximum value and the minimum value of the mortar thickness after the temperature is lowered. It was measured. In the table, five samples are measured, and the number of mortar thicknesses whose ratio between the maximum value and the minimum value is 0.95 or less (minimum value / maximum value ≦ 0.95) is shown. In Examples 1 to 3, which are within the scope of the present embodiment, almost all of them are larger than 0.95, whereas in the comparative example, bricks are tilted by three or more samples, and there is a risk of overhang and dropping.

  Table 2 below shows the effect of this embodiment in an actual furnace. Table 2 shows the number of kilns that were re-repaired by overhanging from the temperature rise to 3 months of operation when the amount of shrinking mortar was changed, and from the observation hole in the ceiling, usually covered The observed wall portion appearance (◎: almost flat, ○: overhang amount of 5 mm or less, Δ: overhang over 5 mm and under 10 mm, x: overhang over 10 mm) is shown. The uppermost plastic refractory has a bending strength of 5 MPa or more, is clay-like, and has almost no moisture. Moreover, the result at the time of setting the mortar (cushion mortar) of the bending strength of 1-2 MPa which shrink | shrinks the uppermost-stage member material 30% is also shown. In Examples 1 to 3, which are within the scope of the present embodiment, no kiln was re-repaired, and good results were obtained.

  In addition, this invention is not restricted to the above-mentioned embodiment, It can change suitably within the description range of a claim. That is, for example, the above-described embodiment is applied to a Karl-still type coke oven, but the partial transshipment repair method of the present invention can be similarly applied to other types of chamber-type coke ovens.

  Thus, according to the partial transshipment repair method of the chamber furnace type coke oven of the present invention, the expansion absorption margin is optimized without using a ceramic board, so that the construction efficiency at the time of partial transshipment repair is improved and the risk of overhang and dropping off is increased. Can be eliminated little or no.

Brief description of symbols

DESCRIPTION OF SYMBOLS 1 Ceiling part 2 Horizontal tunnel 3 Joint 4 Convex dowel part 5 Unshaped refractory

Claims (3)

When repairing bricks that form part of the flue of the combustion chamber of a chamber-type coke oven by transshipment while leaving the ceiling,
Maintain the temperature of the wall on the carbonization chamber side of the flue that remains without being repaired continuously to the flue to be repaired, and the wall facing the wall to be repaired of the flue adjacent to the flue to be repaired at 400 ° C. or higher,
Using a mortar with a linear shrinkage rate of 30% or more from 100 ° C to 800 ° C under a load of 0.1MP on the horizontal joints of the bricks to be transshipped,
The thickness of the mortar is such that the total amount of vertical shrinkage assumed from the room temperature to the operating temperature of the mortar is 50 to 95% of the total amount of vertical expansion expected from the room temperature to the operating temperature of the brick. And set the number of layers,
And the thickness of the mortar per joint is set to be less than the protruding height of the convex dowel part of the brick, and the mortar is disposed.
A method for partial transshipment repair of a coke oven, wherein an irregular refractory material having a bending strength of 5 MPa or more after being cured and dried is used for a connection portion between a remaining ceiling portion and a newly piled portion.   2. The coke oven according to claim 1, wherein the construction position of the mortar is located in a furnace wall brick stacking portion below a brick wall located below one step of bricks having different upper and lower surface areas forming the ceiling portion. Partial transshipment repair method.   The total shrinkage in the vertical direction assumed from the room temperature to the operation temperature of the mortar is 50 to 80% of the total expansion amount assumed in the vertical direction from the room temperature to the operation temperature of the brick. The partial transshipment repair method for a coke oven according to claim 1 or 2, wherein the thickness and the number of layers are set and arranged.

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