JP6572857B2 - Method of dismantling the flue section of a room-type coke oven - Google Patents

Description

  The present invention relates to a method for dismantling a flue portion of a chamber-type coke oven, and more particularly to a dismantling method suitable for disassembling a flue portion in which asbestos is used for an expansion joint portion.

  As shown in FIG. 3, a chamber-type coke oven (hereinafter sometimes referred to simply as “coke oven”) has combustion chambers and carbonization chambers alternately formed above the heat storage chamber in the direction of the furnace group. While charging coal into the chamber, the fuel gas and air heated through the heat storage chamber are combusted in the combustion chamber, and the heat generated in this combustion is passed through the furnace wall that separates the combustion chamber and the carbonization chamber. By supplying to the coal, the coal in the carbonization chamber is carbonized to produce coke.

  This coke oven has a structure in which high-temperature gas circulates inside, so that it is made of refractory bricks and the outside is restrained by iron skin or concrete. After exhausted from the combustion chamber, the exhaust gas (combustion exhaust gas) that has passed through the heat storage chamber is collected in a plurality of small flues made of bricks in the bottom of the concrete furnace provided below the heat storage chamber. It is exhausted from the chimney through the flue. The large flue is a gas flow path that collects exhaust gas flowing through the small flue and exhausts it to the chimney. The main flue is made of brick and the outside is constrained by concrete.

  Since the small flue forms a gas flow path that is long in the direction of the furnace group of the coke oven, expansion joint portions are provided at appropriate intervals in the longitudinal direction in order to absorb the thermal expansion of the flow path. Similarly, expansion joints are also provided in the large flues at appropriate intervals in the longitudinal direction. These expansion joints have a moving part, and in the old structure, asbestos is used in the moving part in order to be able to follow the movement of the flue in this moving part (expansion / contraction due to thermal expansion / contraction). There are many.

  Many of the coke ovens operating in Japan were built in the 1940s and are aging. For this reason, aging renewal is currently planned and implemented in coke ovens throughout Japan. Many old coke ovens are renewed by a method called pad-up, which uses only existing foundations and renews all other brick structures and steel skin hardware. In this update method, it is necessary to dismantle and remove the brick structure formed on the foundation. Patent Document 1 discloses a method for renewing a coke oven that can dismantle a brick wall while improving the safety of a worker who is working in the vicinity when dismantling a brick structure.

Japanese Patent Laid-Open No. 2015-13937

  When asbestos is used in coke ovens, dismantling work must be performed in accordance with relevant laws and regulations such as the Industrial Safety and Health Act and the Air Pollution Control Act. Specifically, it is necessary to perform the dismantling work while sealing the construction area and installing a dust collector etc. to make it negative pressure. In addition, it is decided that workers who perform dismantling work should wear protective equipment and protective clothing to prevent exposure.

  For this reason, in order to perform dismantling as shown in Patent Document 1, it is necessary to seal the entire coke oven when disassembling the coke oven. In addition, the demolition brick waste generated by the dismantling of the coke oven contains asbestos, so it cannot be disposed of in a normal disposal site, and must be disposed of in a controlled disposal site. It is expensive compared to the waste disposal. Therefore, if the entire brick of the coke oven is to be disposed as asbestos-containing brick waste, a very high disposal cost is required.

  Therefore, the object of the present invention is to solve the problems of the prior art as described above, simplify the dismantling work of the flue, and minimize the generation amount of demolition waste containing asbestos. The object is to provide a method for dismantling the flue part of a coke oven.

  As a result of repeated studies to solve the above-mentioned problems, the present inventors (i) the place where asbestos is used in the coke oven is only the expansion joint portion provided in the small flue and the large flue, respectively. At a certain point, (ii) the large flue and the multiple small flues connected to it have a structure that is isolated from the outside (atmosphere) by concrete and communicates with the outside in order to collect combustion exhaust gas and flow it to the chimney. Focusing on the fact that it is relatively easy to create a sealed space that is cut off from the outside due to the small number of openings and connections, when disassembling the flue, first the large flue and the small smoke connected to it The road is a sealed space that is blocked from the outside, and only the expansion joint part is disassembled in a state where the sealed space is negatively pressured, and the generated asbestos-containing demolition waste is carried out to the outside. Solution It was invented a new dismantling method of performing the dismantling of the entire flue portion by.

That is, the features of the present invention for solving the above problems are as follows.
[1] A chamber furnace-type coke oven in which a large flue and a flue portion composed of a plurality of small flues connected to the large flue are sequentially disassembled according to the following procedures (A) to (D). A method for dismantling the flue of a coke oven.
(A) A small flue is provided on the large flue with a carry-out port for carrying out demolition debris generated in the flue to the outside and an exhaust device for exhausting the inside of the flue and making it negative pressure. By closing the path between the combustion chamber and the connection between the large flue and the chimney, the flue is sealed from the outside.
(B) The inside of the flue is depressurized by exhausting the exhaust system.
(C) The expansion joint part of a small flue and a large flue is disassembled, and the dismantled waste is carried out from the carry-out port to the outside.
(D) Dismantle the entire flue after releasing the negative pressure / sealed state of the flue.

[2] In the dismantling method of [1] above, in step (A), the small flue and the combustion chamber are closed by closing a closing valve provided in a gas flow path for discharging the combustion exhaust gas from the combustion chamber to the small flue. A method for disassembling the flue portion of a chamber-type coke oven, characterized in that the path between the two is closed.
[3] In the dismantling method of [1] or [2] above, in step (A), the vicinity of the end of the large flue on the chimney side is closed with concrete, thereby connecting the large flue and the chimney. A method for disassembling the flue portion of a chamber furnace type coke oven, characterized in that:
[4] In the dismantling method according to any one of [1] to [3] above, a work chamber provided with a front chamber is provided outside the carry-out port provided in the large flue, and the demolition waste is carried out through the work chamber. A method for disassembling a flue portion of a chamber-type coke oven, characterized in that

  According to the present invention, in the demolition of the flue portion of the chamber furnace coke oven, the dismantling operation is simplified while minimizing the sealed range required for the dismantling operation while complying with the procedures specified by laws and regulations. Moreover, the generation amount of the demolition waste containing asbestos can be minimized, and the load on the management-type disposal site for disposing the demolition waste containing asbestos can be reduced. In addition, the flue part can be easily disassembled with a minimum sealed area, and the amount of dismantled debris containing asbestos is kept to a minimum, and the disposal cost of dismantled debris can be reduced. It is possible to keep down the cost of dismantling the flue section of a room-type coke oven.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of a demolition method of the present invention, and shows a plan view of a flue part to be dismantled and equipment used for the dismantling, and an explanatory view showing a dismantling work situation of an expansion joint part of the flue part Detailed view of the outlet provided in FIG. Longitudinal sectional view of combustion chamber and substructure of chamber coke oven

  In the coke oven, asbestos is used only in the expansion joints provided in the small flue and the large flue, respectively. The small flue is provided in the concrete that forms the bottom of the coke oven, and the only part that communicates with the outside is the connection between the path through which the flue gas flows from the combustion chamber and the large flue. . The large flue is provided in the concrete, and one end side is connected to a plurality of small flues and the other end side is connected to the chimney. In this way, the large flue and the multiple small flues connected to it have a structure that is isolated from the outside (atmosphere) by concrete in order to collect combustion exhaust gas and flow it to the chimney. Only the path between the small flue and the combustion chamber and the connection between the large flue and the chimney. Therefore, if the path between the small flue and the combustion chamber and the connection between the large flue and the chimney are closed, the large flue and the multiple small flues connected to it are sealed from the outside. It can be made into the state (namely, sealed space blocked | interrupted with the exterior). And if the expansion joint part of a small flue and a large flue is dismantled in this state, the asbestos dismantling in the sealed state corresponding to a law regulation will be performed. The present invention has been made paying attention to the above points.

In the present invention, in the chamber furnace type coke oven, the large flue and the flue portion composed of a plurality of small flues connected to the large flue are sequentially disassembled by the following procedures (A) to (D).
(A) A small flue is provided on the large flue with a carry-out port for carrying out demolition debris generated in the flue to the outside and an exhaust device for exhausting the inside of the flue and making it negative pressure. By closing the path between the combustion chamber and the connection between the large flue and the chimney, the flue is sealed from the outside.
(B) The inside of the flue is depressurized by exhausting the exhaust system.
(C) The expansion joint part of a small flue and a large flue is disassembled, and the dismantled waste is carried out from the carry-out port to the outside.
(D) Dismantle the entire flue after releasing the negative pressure / sealed state of the flue.

1 and 2 show an embodiment of the demolition method of the present invention. FIG. 1 shows a plan view of a flue part to be dismantled and equipment used for the dismantling, and expansion of the flue part. Explanatory drawing which shows the disassembly work condition of a joint part, FIG. 2 is detail drawing of the installation provided in the carrying-out port in FIG. 1, and its outer side. FIG. 3 is a longitudinal sectional view of the combustion chamber of the chamber furnace type coke oven and its lower structure.
In the figure, 1 is a large flue, 2 is a plurality of small flues connected to the large flue 1, 3 is a chimney to which the large flues are connected, and 4 is provided at intervals in the longitudinal direction of the large flue 1. Expansion joint portions 5 and 5 are expansion joint portions provided at intervals in the longitudinal direction of each small flue 2.

Hereinafter, based on these drawings, the details of the steps (A) to (D) will be described.
In the step (A), an opening is provided in a portion of the large flue 1 where the expansion joint portion is not provided, and a discharge port 6 is provided for carrying out demolition waste generated in the flue portion to the outside. A work chamber 8 for loading demolition waste into a transport truck or the like is provided outside the carry-out port 6, and the flue portion is directly opened to the outside when the transport truck or the like enters and exits the work chamber 8. The front chambers 9a and 9b are provided on the inlet side and the outlet side of the working chamber 8 so that there is no such problem.

In FIG. 2, 10a and 10b are open / close doors provided at the entrances of the front chambers 9a and 9b, and 11a and 11b are open / close doors provided at the entrances and exits between the work chamber 8 and the front chambers 9a and 9b. Further, a front chamber 12 for an operator to enter and exit the flue section and the working chamber 8 is provided facing the communication path 13 that connects the working chamber 8 and the carry-out port 6.
It is preferable that the carry-out port 6 has a size that allows a heavy machine used for dismantling the expansion joint portions 4 and 5 and conveying demolition waste to enter and exit. Since the work chamber 8 performs the work of loading the dismantled scraps that have been carried out onto a transporting truck or the like, it is preferable that the work chamber 8 has a size that enables such work.

Further, in the step (A), an exhaust device 7 (such as a blower) for exhausting the inside of the flue to create a negative pressure is installed and connected to a portion of the large flue 1 where there is no expansion joint. The exhaust device 7 is provided with a dust collector 14 for collecting and removing dust contained in the exhaust.
Further, in the step (A), the path (gas flow path) between the small flue 2 and the combustion chamber and the connection part between the large flue 1 and the chimney 3 are closed, and the flue part is externalized. A sealed state (sealed space) that is blocked from In the chamber-type coke oven, a closing valve 15 (FIG. 3) is provided in a gas flow path through which combustion exhaust gas flows into the small flue 2 from the combustion chamber. If the closing valve 15 is closed, the small flue 2 The path between the combustion chamber and the combustion chamber can be closed. Further, in order to make the sealed state more reliable, the sealing valve 15 may be closed and then sealed with mortar or the like. Moreover, in order to close the connection part between the large flue 1 and the chimney 3, it is possible to take an appropriate method such as closing the vicinity of the end of the large flue 1 on the chimney side with a closing member 16 such as concrete. it can.

  In the next step (B), the exhaust device 7 is operated, and the inside of the flue is made negative pressure by about −100 to −50 mmAq (−9.8 to −4.9 hPa) with respect to the atmospheric pressure. If the pressure inside the flue is excessively negative, air may move abruptly when entering and leaving the front chambers 9a and 9b, and dust may be generated. If the degree of negative pressure is small, the air in the flue section may leak outside through the work chamber 8 due to the movement of heavy machinery in the flue section.

In the next step (C), the expansion joint portions 4 and 5 of the large flue 1 and the small flue 2 are disassembled. In the dismantling work of the expansion joint parts 4 and 5, asbestos is mainly removed by an operator, and bricks that may contain asbestos are dismantled as necessary. After dismantling waste (asbestos-containing dismantling waste) generated by the dismantling of the expansion joint parts 4 and 5 from the carry-out port 6, the work room 8 is loaded onto a transport truck and the like, and then passes through the front chamber 9b. Transport outside.
In the next step (D), the operation of the exhaust device 7 is stopped, the negative pressure / sealed state of the flue portion is released, and the entire flue portion is disassembled with a heavy machine or the like. When releasing the sealed state of the flue, the exhaust device 7 and the working chamber 8 may be removed.
According to the present invention, while leaving the upper structure (combustion chamber, carbonization chamber, heat storage chamber, etc.), only the flue portion can be disassembled, along with the disassembly of the flue portion according to the method of the present invention, The upper structure may be dismantled.

  Dismantling of the flue portion of a chamber-type coke oven having 51 carbonization chambers was carried out in the form as shown in FIGS. The expansion joint part is disassembled and the asbestos-containing demolition waste is carried out in a state where the pressure inside the flue part made into a sealed space is made negative by an exhaust device (blower), and then the negative pressure and sealed state of the flue part is released. After that, the entire flue section was dismantled and completed in 10 days. In the case of disassembling the flue part integrally with the whole chamber coke oven sealed as in the conventional method, it has been estimated that it takes 16 days to dismantle the flue part. The construction period was shortened by 6 days by using.

  Further, in this example, the temperature of the flue portion was lowered to almost normal temperature, so the expansion joint portion was opened due to the contraction of the brick, and the inserted asbestos yarn could be easily scraped, so that the asbestos dismantling At the same time, the expansion joint part could be dismantled with almost no bricks to be dismantled (to the extent that brick waste was generated due to the loss of bricks around asbestos). The small flue was eventually demolished together with the concrete forming the furnace bottom, but the large flue dismantled only the refractory bricks forming the flue, and the concrete covering the refractory bricks was not dismantled.

For this reason, the generated asbestos-containing demolition waste was only asbestos that had been inserted into the expansion joint part and brick waste that had been lost around the asbestos, and the amount thereof was approximately 1 t as a whole. On the other hand, demolition waste containing no asbestos was generated in a total of 5500 tons of fire bricks forming the small flues and large flues and the concrete around the small flues.
When the flue part is dismantled by the above-mentioned conventional method, the concrete forming the furnace bottom and the bricks forming the small flue and the large flue all become asbestos-containing demolition waste. This means that almost 5500t of demolition waste can be reduced. Moreover, since the demolition waste which does not contain asbestos can be recycled, the load on the management disposal site could be reduced.

DESCRIPTION OF SYMBOLS 1 Large flue 2 Small flue 3 Chimney 4, 5 Expansion joint part 6 Carriage outlet 7 Exhaust device 8 Work room 9a, 9b Front room 10a, 10b Open / close door 11a, 11b Open / close door 12 Worker front room 13 Connection way 14 Dust collector 15 Closing valve 16 Closing member

Claims (3)

In a furnace-type coke oven, a method for dismantling a flue portion that is installed in a horizontal direction and includes a large flue and a plurality of small flues connected to the large flue ,
Disassembly of the flue part where asbestos is used only in the expansion joint part of the small flue and the large flue is performed in order of the following (A)-(D), How to dismantle the flue.
(A) A carry-out port for carrying out demolition debris generated in the flue section to the outside and an exhaust device for exhausting the inside of the flue section to negative pressure are provided for the large flue and from the combustion chamber. The passage between the small flue and the combustion chamber is closed by closing the shut-off valve provided in the gas flow path for discharging the combustion exhaust gas to the small flue , and the connection between the large flue and the chimney is closed. By closing with a closing member , the flue portion is made a sealed space blocked from the outside.
(B) The inside of the flue is depressurized by exhausting the exhaust system.
(C) The expansion joint part using the small flue and asbestos of the large flue is dismantled, and the dismantling waste is carried out from the carry-out port to the outside.
(D) Dismantle the entire flue after releasing the negative pressure / sealed state of the flue. 2. The furnace according to claim 1, wherein in step (A), the connection between the large flue and the chimney is closed by closing the vicinity of the end of the large flue on the chimney side with concrete. Method of dismantling the flue part of the coke oven. The chamber furnace type coke according to claim 1 or 2 , wherein a work chamber provided with a front chamber is provided outside a carry-out port provided in a large flue, and demolition waste is carried out through the work chamber. Dismantling method of furnace flue.

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