JP2018039921A - Demolition method of retaining wall of coke oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a demolition method of a retaining wall, which in a renovation construction in which a coke oven is stopped and demolished, and bricks and retaining walls on an oven bottom are demolished and renovated, avoids a hitch operation of small-divided retaining walls, reduces fall risk of the small-divided retaining walls and accident risk of an operator, and efficiently demolishes the retaining wall while increasing safety of an operator.SOLUTION: A retaining wall demolition method of a coke oven, in which demolished bricks are laid on a furnace bottom on an inner-oven side, a gap that penetrates through the retaining wall is formed in a longitudinal direction in the retaining wall, on a retaining wall surface on an opposite oven side, the gap in a horizontal direction which has a depth that cuts a reinforcement on the opposite oven side but does not cut the reinforcement on the inner-oven side is formed, and with a demolishing machine, the retaining wall is pulled down from the gap in the horizontal direction on the demolished bricks laid on the inner-oven side.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a retaining wall dismantling method for a coke oven.

  A coke oven, also called a chamber-type coke oven, is a facility that blocks coke and heats coal in a carbonization chamber to produce coke by batch processing, and is a self-supporting furnace composed of refractory bricks. In this coke oven, a heat storage chamber is disposed in the lower layer portion, and a carbonization chamber and a combustion chamber are disposed in the upper layer portion. Usually, a large number of carbonization chambers and combustion chambers are alternately arranged, and the direction in which these many alternating chambers are arranged is called the furnace group length direction. On the other hand, the longitudinal direction of the carbonization chamber is referred to as the furnace length direction. Concrete retaining walls are installed at both outermost ends of the coke oven in the furnace length direction (Patent Document 1). This retaining wall is a structure made of reinforced concrete, and functions to position and hold the furnace body while suppressing thermal expansion of the furnace body in the length direction of the furnace group. This retaining wall is approximately 16m in height and width and 900mm in thickness.

  By the way, when the coke oven is operated for a period exceeding 20 to 30 years and repeatedly subjected to dry distillation and discharge, the brick wall forming the combustion chamber and the carbonization chamber is deteriorated and easily collapses. For this reason, the renewal work which disassembles once and reconstructs the structure part which comprises a combustion chamber, a carbonization chamber, and a brick wall (patent documents 2, 3) is performed.

On the other hand, since the retaining wall has higher strength and durability than the combustion chamber and the carbonization chamber, the retaining wall may be left and reused when the brick wall is disassembled.
However, if the operating period of the coke oven exceeds 40 years, the concrete that constitutes the retaining wall also deteriorates, so that it tends to collapse. Retaining wall concrete is alkaline during construction, but becomes neutral from the surface after long-term use. When neutralized, fine cracks enter and the strength decreases. Further, as the neutralization of concrete progresses, the reinforcing steel in the inside becomes a corrosive environment and the reinforcing steel expands due to oxidation, and this also causes fine cracks in the concrete. For this reason, the retaining wall of the coke oven that has been in operation for more than 40 years is also demolished and renewal work is performed to rebuild a new retaining wall.

  When dismantling the retaining wall of the coke oven, steps 1 to 4 (referred to as normal steps) that can be considered as normal work procedures for safe disassembly will be described below.

1. Before dismantling the retaining wall, the furnace body bricks that make up the heat storage chamber, carbonization chamber, and combustion chamber above the hearth plate that is the top of the foundation structure are dismantled and removed.
Since the furnace body brick is deteriorated more than the retaining wall, it is necessary to disassemble in advance in order to prevent collapse during work. In addition, the demolished bricks will be removed to secure a working space for dismantling the retaining walls.

2. A temporary scaffold for retaining wall dismantling will be installed on the hearth so as to cover the entire retaining wall inside the furnace.
The inside of the furnace in which the heat storage chamber, the carbonization chamber, and the combustion chamber of the retaining wall are configured is referred to as RS, and the counter-reactor side that is the opposite side is referred to as OS. The retaining wall is difficult to disassemble at a time, and if it is destroyed directly with a hammer of a dismantling machine, fragments will scatter widely, so in the retaining wall 1 shown in FIG. , Break up into small pieces. A temporary scaffold for the work will be installed inside the furnace.

3. A wire saw for splitting the retaining wall is installed, and the retaining wall is divided into 7 parts in the height direction and 5 parts in the lateral direction by the wire saw (dividing into small blocks).
As shown by the alternate long and short dash line in FIG. 1A, the small size of the retaining wall 1 can be divided into seven parts in the height direction and five parts in the horizontal direction. If it is this size, it will be 15 tons per piece, and it is within an allowable weight when it is lowered by a crane described later.
At the time of division, as shown by the solid line in FIG. 1 (B), while cutting the horizontal cut 3 with a wire saw in the lateral direction of the upper first stage, the cutting proceeds while attaching the fall prevention metal fitting to the cut. . Moreover, it cut | disconnects with a wire saw in order to make the longitudinal cut 2 vertically.

4). Place the crane on the hearth, hang the block with the crane, remove the fall prevention fittings, and hang the block with the crane.
As shown by the solid line in FIG. 1 (C), the block that has been cut vertically and horizontally with a wire saw and separated from the retaining wall 1 is lowered onto the hearth by a crane. This is repeated to dismantle the retaining wall 1. In addition, in FIG. 1, description of a scaffold, a wire saw, and a fall prevention metal fitting is abbreviate | omitted.

Japanese Patent Laying-Open No. 2015-187218 Japanese Patent Laid-Open No. 2015-13937 JP 2013-199559 A

However, such a retaining wall dismantling procedure has the following problems.
1. The retaining wall is reduced in strength due to the heat effect during operation of the coke oven, and the risk of block collapse during slinging (for example, opening a through hole in the block and passing the rope through) a wire rope to hang the block on the crane. There is still a risk of damaging the hearth by dropping the block.
2. In order to reduce the risk, it must be divided into subdivisions, resulting in lower construction efficiency. In terms of days, it took 23 days only during the retaining wall dismantling period, and 35 days from brick dismantling to completion of retaining wall dismantling.
3. Since a scaffold is required inside the furnace (RS), the scaffold cannot be assembled until the brick dismantling is completed, and the retaining wall dismantling cannot be started.

  In the construction where the coke oven is stopped and dismantled, and bricks and retaining walls on the hearth are dismantled and renewed, the safety of workers is increased and the retaining walls are dismantled efficiently. In particular, we present a retaining wall dismantling method that avoids the slinging work of the divided retaining wall and reduces the risk of falling the broken retaining wall and the operator's disaster risk.

The gist of the present invention for solving the above problems is as follows.
(1) Retaining wall dismantling method for coke oven, dismantling brick on the hearth plate inside the furnace, making vertical cuts through the retaining wall in the retaining wall, Make a horizontal cut with the depth of the cut until the rebar on the counter-furnace side is cut, and the depth inside the furnace without cutting the reinforcing bar inside the furnace, and with a demolition machine into a demolished brick with a retaining wall on the inside of the furnace Coke oven retaining wall dismantling method characterized by pulling down from horizontal cut.
(2) In the method described in (1), before the retaining wall is pulled down by the demolition machine, the inside of the horizontal cut furnace is shaved with a breaker of the demolition machine, and the coke is pulled down Retaining method for retaining wall of furnace.
(3) In the method according to (1) or (2), the retaining wall of the coke oven is characterized by leaving a brick structure close to the inside of the retaining wall at the start of the operation for making a longitudinal cut. Dismantling method.

1) Retaining wall separation work ensures that the strength is secured without installation of fall-prevention metal fittings when leaving a horizontal cut (for example, using a wall saw) to leave the furnace rebar without cutting it. In addition, it is not necessary for the worker to work close to install the fall-preventing metal fitting on the weak retaining wall whose strength has been reduced, and the safety of the worker is ensured.
2) Since the divided retaining wall is pulled down and disassembled, slinging work is avoided, and it is possible to prevent a falling accident (man-made disaster) and damage to the retaining wall and hearth board due to dropping.
3) By laying the demolished brick on the hearth plate, the impact when the retaining wall is pulled down is spread and absorbed by the brick as a cushion, and there is no damage to the hearth plate, noise and dust generation problems.
4) Since the retaining wall is pulled down and disassembled, it is not necessary to lower the retaining wall divided by a crane, and the division can be performed in large units.
5) The retaining wall splitting work is done by leaving the brick structure close to the inside of the retaining wall furnace at the beginning of the longitudinal cutting (wire saw) work to make a vertical cut, so that the brick structure can be used as a scaffold inside the furnace. Thus, there is no need for temporary scaffolding inside the furnace, and horizontal crossing (wall saw) that cuts in the horizontal direction can be performed from the counter-furnace side, so there is no need for temporary scaffolding inside the furnace. Thereby, it becomes possible to wrap brick dismantling, vertical cutting (wire saw), and crossing (wall saw) work, and the total construction period of brick dismantling and retaining wall dismantling can be significantly shortened.

The figure which shows the conventional retaining wall dismantling procedure The figure which shows the hole for wire saw introduction | transduction of the retaining wall seen from the furnace inner side, and a longitudinal cut, (A) is an AA arrow line view of (B) It is a cross-sectional view of the retaining wall seen from the furnace length direction, showing the procedure for making a longitudinal cut with a wire saw It is sectional drawing of the retaining wall seen from the furnace length direction, and the figure which shows the horizontal cut in this invention It is sectional drawing of the retaining wall seen from the furnace length direction, and is the figure which shows the procedure which pulls down the retaining wall of this invention

  When dismantling the retaining wall by applying the present invention, the bricks of the combustion chamber, the carbonization chamber, and the heat storage chamber are dismantled. Prior to dismantling the brick, the backstay, the furnace frame, and the protective plate are dismantled sequentially, and then the brick is dismantled. The dismantling of the brick here refers to breaking the state of the combustion chamber, the carbonization chamber, and the shape and structure of the heat storage chamber, and making the brick into a debris state. At this time, each broken brick may or may not be broken.

  Next, the demolished brick is laid on the hearth of the inside RS of the retaining wall 1 until it reaches a certain height or thickness. In a later step, the divided retaining wall 1 is pulled down on the laid demolished brick 10. By disposing the demolished brick 10, the demolished brick 10 serves as a cushion for protecting the hearth plate from the retaining wall 1 that has been brought down. Since the demolition brick 10 is so-called waste that is always generated on the hearth plate during the demolition process, the cost and labor of preparing a special cushion material are not required. The height at which the demolished brick 10 is spread is not particularly limited, but is high enough to protect the hearth plate from the impact of the retaining wall 1 that rises in a mound shape and is pulled down and dropped. Specifically, although it depends on the size and weight of the divided retaining wall 1, the height is 3 m or more.

On the other hand, in parallel with the dismantling of the brick, a vertical cut 2 and a horizontal cut 3 penetrating the retaining wall 1 are made in the retaining wall 1.
By making the vertical cut 2, the retaining wall 1 can be pulled down. As a specific method, a wire saw can be used. In order to make the cut 2, first, as shown in FIGS. 2 and 3A, the wire saw introduction hole 4 through which the wire saw 5 passes is made to penetrate the retaining wall 1. Then, as shown in FIG. 3B, the wire saw 5 is passed through the upper and lower two wire saw introduction holes 4, and the wire saw 5 is rotated by the sawing machine 6, so that the upper and lower two wire saw introduction holes. Cut between four. In FIG. 2, the cut that includes the vertical cut 2 is performed by dividing it into three in the vertical direction, and all of the upper stage and the two cuts are interrupted. As will be described later, at this stage, as shown in FIGS. 3A and 3B, the brick structure 9 is placed near the retaining wall 1 of the furnace inside RS, and the wire saw introduction hole 4 having a predetermined height. As a scaffold for opening the wire saw 5 and leaving it, it is preferable to leave it to a predetermined height. When the cutting is finished, for example, the vertical cut 2 is also made in another part as shown in FIG. 3C, which is a part immediately below FIG. 3B. In FIG. 3, the longitudinal cut 2 is made from the upper stage, but it is not necessarily made from the upper stage, and the cut may be made from the lower stage. In addition, if the deck connecting the retaining walls remains in the reaction furnace side OS, the sewing machine 6 may be installed on the floor of the deck, and the scaffolding is built in the reaction furnace side OS. For example, it may be installed on a scaffold.

  Next, as shown in FIG. 4, a horizontal cut 3 is formed on the surface of the retaining wall 1 on the reaction furnace side OS until the reaction furnace side reinforcing bar 7 is cut and the furnace inner reinforcement 8 is not cut. Insert.

  Since the retaining wall 1 is made of reinforced concrete, as shown in FIG. 4, the counter-reactor-side reinforcing bar 7 and the furnace-side reinforcing bar 8 are embedded in the inner-reactor side and the inner side of the furnace, respectively. In the present invention, when the horizontal cut 3 is made, the anti-reactor side reinforcing bar 7 is cut and the furnace inner side reinforcing bar 8 is left uncut until it is pulled down. As a result, the retaining wall 1 is broken and pulled down by the horizontal cut 3. Further, by leaving the furnace inner reinforcing bar 8, it is possible to prevent the upper part from shifting or collapsing from the horizontal cut 3, so that it is not necessary to install a fall prevention metal fitting until it is pulled down. In order to make the horizontal cut 3, for example, a wall saw having a diamond blade may be used.

  When the cuts 2 and 3 are finished and the demolition brick 10 is laid on the hearth plate inside the furnace as shown in FIGS. 5 (A) to 5 (C), the horizontal cut of the retaining wall 1 is performed by the demolition machine. 3 (solid line in FIG. 5A), bent from the horizontal cut 3 (two-dot chain line in FIG. 5A, solid line in FIG. 5B), and tilted onto the demolished brick 10 (FIG. 5). (B). Next, it is torn off (FIG. 5C). In this way, the demolished brick 10 is laid in advance, and the retaining wall 1 is pulled down thereon, whereby the demolished brick 10 becomes a cushion and the torn down retaining wall (divided retaining wall) and hearth The panel can be protected from damage, and vibration, noise, shock, dust generation, and debris can be prevented.

  Furthermore, since the divided retaining wall (divided part) is pulled down and disassembled, a slinging operation is avoided, and it is possible to prevent a falling accident (man-made disaster) or damage to the retaining wall or the hearth plate due to dropping. Moreover, since it is not necessary to lower the dividing portion with a crane, the dividing portion can be made into a large block, so that the number of divisions is reduced and the disassembly efficiency is good.

  In the present invention, it is preferable that the inside of the furnace of the horizontal cut 3 is shaved with a breaker of the demolition machine before the retaining wall is pulled down by the demolition machine. As a result, the division at the cut 3 becomes smooth and can be pulled down more easily. The part to be sharpened is the inside of the furnace directly behind the horizontal cut 3, and the depth to be cut is such that the inside reinforcing bar 8 is not cut.

  In the present invention, it is preferable to leave the brick structure 9 at the start of the operation of making the longitudinal cut 2. By leaving the brick structure at the start of the operation of making the vertical cut 2, the operation of passing the wire saw 5 through the wire saw introduction hole 4 can be performed on the brick structure 9 as a scaffold. That is, until the operation of passing the wire saw 5 through the wire saw introduction hole 4 is finished, the brick structure 9 having a close position and a height at which the height of the wire saw introduction hole 4 can be accessed is left. preferable. If the wire saw 5 can be introduced into the wire saw introduction hole 4 having a target height, the brick structure 9 above the wire saw 5 may be disassembled. Further, the horizontal cut 3 may be made only from the reactor side OS. For this reason, it is not necessary to assemble a scaffold in the furnace inner side RS. Since there is no need to assemble a scaffold inside the furnace, it is not necessary to complete the dismantling and removal of the brick before starting the work of making the cut. Can be parallel. Thereby, the total construction period of brick demolition and retaining wall demolition can be shortened significantly. Moreover, since the process itself of assembling a scaffold on the furnace inner side RS can be omitted, work efficiency is good.

  As mentioned above, by omitting the installation of the scaffolding inside the furnace and paralleling the work of demolition of the brick and the start of making a cut in the retaining wall, the start of the retaining work of the retaining wall can be accelerated by about 15 days. It was. In addition, it does not require detailed and precise work to lower the divided retaining walls one by one with a crane, and it can be handled by pulling down the large divided retaining walls, so the period from the incision to the completion of the dismantling of the retaining walls is 6 I was able to advance about a day. In total, the period from the start of brick demolition to the end of retaining wall demolition could be shortened by about 17 days compared to the normal process.

  According to the present invention, when the retaining wall of the coke oven is dismantled, the total construction period of the brick dismantling and retaining wall dismantling is greatly shortened, and the installation of fall prevention metal fittings and slinging work is avoided, resulting in a fall accident (man-made disaster) or falling It has extremely useful industrial applicability to prevent damage to retaining walls and hearth, noise and dust generation.

DESCRIPTION OF SYMBOLS 1 ... Retaining wall 2 ... Longitudinal cut 3 ... Horizontal cut 4 ... Wire saw introduction hole 5 ... Wire saw 6 ... Sewing machine 7 ... Counter-reactor side reinforcement 8 ... Furnace inner reinforcement 9 ... Brick structure 10 ... Demolition Brick RS ... Furnace inside OS ... Counter-furnace side

Claims (3)

  A method for dismantling the retaining wall of a coke oven, in which demolished bricks are laid on the hearth inside the furnace, a vertical cut is made through the retaining wall, and the depth of the cut is A horizontal cut is made until the rebar on the counter-furnace side is cut and the depth inside the furnace is not cut. Coke oven retaining wall dismantling method characterized by pulling down from a break.   The method according to claim 1, wherein the inside of the horizontal cut furnace is shaved with a breaker of the dismantling machine and the retaining wall is pulled down before the retaining wall is pulled down by the dismantling machine. Wall demolition method.   The method according to claim 1 or 2, wherein a brick structure close to the inside of the retaining wall furnace is left at the start of an operation for making a longitudinal cut.

Images