JP4122015B2 - Plant cleaning method, asbestos removal method and dismantling treatment method - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an internal cleaning method for a plant to be demolished in a plant dismantling process, and in particular, a cleaning method and a mist generator which are filled with a chemical mist in advance in the plant and easily removed from the residue before cleaning with high-pressure water. About.

  For example, in the demolition work of an incinerator plant, dioxins and lead and other harmful substances that have adhered to and deposited on incinerators and flues are removed sufficiently for many years to prevent scattering of pollutants to the surrounding environment during demolition. It is obliged to perform actual dismantling after cleaning. In this cleaning process, in accordance with established manuals and guidelines, after collecting residual contaminants with human power or a suction hose, the worker actually enters the contaminated area and sprays it with high-pressure water to clean it, or the contaminated area is pressurized. A water injection nozzle is inserted and washed (for example, Patent Document 1).

In recent years, health damage caused by asbestos (asbestos) has become a problem, and when disassembling a plant with asbestos on the inner wall, it is necessary to reliably remove the asbestos in advance so that it is not scattered. Moreover, even when the operation of the plant is continued, it is dangerous to leave asbestos, and asbestos removal work is actively carried out. In such a construction method, before removing asbestos, workers are required to enter the plant, spray spray nozzles on the entire surface with spray nozzles, and prevent scattering in the subsequent removal process. .
JP 2004-316862 A

  However, in the plant cleaning process, for example, when the inside of the plant has a complicated shape or is high or wide, there are places where workers cannot spray high-pressure water directly and effectively, and contaminants remain. was there. In addition, for example, in the case of combustion equipment, combustion and cooling are repeated for many years, clinker etc. with strong and stable properties are stuck, and these clinker etc. do not peel off just by spraying with high pressure water and can not be washed sufficiently was there. For this reason, the plant is dismantled and carried out despite the insufficient cleaning, and there is a possibility that pollutants are scattered outside.

  In addition, even when the plant is large in the asbestos removal method, it takes a lot of time and effort to spray the anti-scattering agent on the entire surface of the plant with the spray nozzle, and it may cause unevenness in the spraying of the anti-scattering agent. There is a possibility that a location where the value is not sufficient will occur. In addition, when asbestos is applied to the inner wall of the chimney, there is a problem that the spray nozzle does not reach the upper part and the anti-scattering agent cannot be sprayed.

  The present invention has been made in view of this point, and prior to cleaning with high-pressure water and asbestos removal, the chemical mist is soaked in the adhering residue by filling the chemical mist in the plant and placing it for a predetermined time. It is an object of the present invention to provide a method, a plant dismantling treatment method, and a mist generator used therefor, which include a step of spreading the anti-scattering agent evenly over asbestos so that it can be easily removed in the process.

  The present invention includes a step of recovering residues such as residual ash and metal powder in the plant, a step of filling the mist with the mist and leaving it for a predetermined time, and a step of spraying high-pressure water on the inner wall of the plant for cleaning. And a cleaning method for a plant.

  It is desirable that the mist contains an acidic or alkaline chemical.

  Moreover, it is desirable that the mist contains a colorant.

  Further, the present invention provides a method for removing asbestos from a plant facility in which asbestos is applied to an inner wall, a step of filling the plant with a mist mixed with an anti-scattering agent and leaving it for a predetermined time, and then maintaining the inside of the plant at a negative pressure. And a step of removing asbestos.

  It is desirable that the step of filling the plant with mist includes a step of operating a blower in the plant to convect the mist.

  Moreover, this invention relates to the plant demolition processing method characterized by providing said process.

  The present invention also relates to a mist generator used in the above method, wherein at least the inner wall of the liquid tank is made of stainless steel.

  In this mist generator, it is desirable that the height of the injection nozzle can be extended to at least about 3 m above the ground.

  In the plant cleaning method of the present invention, since there is a step of filling the mist in the plant and allowing it to stand for a predetermined time before washing the inside of the plant with high-pressure water, the mist permeates the deposit on the inner wall of the plant and is sprayed later. Easily dropped with high-pressure water. Therefore, according to this cleaning method, contaminants can be reliably removed by washing, the plant can be safely disassembled, and contamination of the surrounding environment can be reliably prevented.

  In addition, by including a chemical solution such as dilute sulfuric acid or sodium hydroxide in the mist, it is possible to easily decompose and drop dioxins and metals adhering to the plant. With such a configuration, even in places where high-pressure water cannot be sprayed directly, contaminants can be washed simply by allowing water to flow from above, and the plant can be safely disassembled and removed. be able to.

  Moreover, when a coloring agent is included in mist, a plant inner wall will be colored by a mist process. As a result, an operator who sprays high-pressure water can be prevented from touching the location where the chemical mist is adhered, or a location where washing with high-pressure water is insufficient can be easily grasped.

  Further, according to the asbestos removal method of the present invention, even when the plant is large, the scattering inhibitor can be sprayed uniformly, so that the scattering inhibitor does not become uneven. Further, for example, even in a plant having a height such as a chimney, the anti-scattering agent can be suitably attached without unevenness.

  Also, if the air in the plant is convected during mist spraying so that the mist spreads throughout the plant, there will be no places where contaminants are difficult to fall off when high-pressure water is sprayed later, ensuring decontamination and safety. The plant can be dismantled.

  Further, if the inner wall of the liquid tank of the mist generator is made of stainless steel, corrosion and deterioration due to the chemical solution can be prevented and the durability of the mist generator can be improved. Further, if the spray nozzle of the mist generator can be extended, the mist can be suitably sprayed from a high position in a tall plant such as an incinerator chimney.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a schematic perspective view showing an embodiment of a mist generator used in the plant cleaning method of the present invention. As shown in the figure, the mist generator 1 includes a liquid tank 3 made of stainless steel, a support column 4 that can be extended upward, a spray nozzle 5 attached to the top of the support column 4, a liquid tank 3, and the like. A carriage unit 6 is provided. A liquid and air hose 7 extends from the liquid tank 3 to the spray nozzle 5. This hose 7 surrounds the support | pillar 4 helically, and has the length which can respond | correspond enough even when the support | pillar 4 is extended | stretched. The support | pillar 4 is an extension | expansion type | formula and can arrange | position a spray nozzle to the height of about 1 m-2.5 m above the ground, Preferably it is 3 m or more. The spray nozzle 5 is a spray-type sprayer. For example, up to four nozzle ports can be added to spray mist in all directions. The spray amount can be set between about 1 and 17 L / h, and the particle diameter of the mist is about 7 to 11 μm. The mist generator 1 can operate as a timer by setting a start time and an end time in advance. Such a mist generator 1 can be used by changing the liquid tank 3 of a commercially available sprayer to stainless steel, and since the configuration of the spray nozzle and the control timer are well known, detailed description thereof is omitted. The spraying method is not limited to the spray method, and may be a vaporization method or an ultrasonic method.

  A plant cleaning method and a dismantling method using this mist generator will be described below. FIG. 2 is a diagram illustrating a configuration of a dismantling site of an incinerator facility as an example of an application target of the present invention. The incinerator dismantling equipment shown in the figure is roughly divided into a work site 10 that is closed and maintained at a negative pressure, and a preparation chamber 20 that is provided at the entrance / exit of the work site 10.

  The incinerator facility to be dismantled has an indoor part 11 and an outdoor part 12, and the work site 10 is configured by closing the whole in an airtight manner. That is, in the building surrounding the indoor portion 11, gap portions such as openings and windows are closed using a flameproof sheet and a weather tape, and a curing facility is assembled so that the outdoor portion 12 is included. This curing equipment is constructed by assembling a beam frame with metal pipes, leaving a necessary part such as an entrance and exiting a flameproof sheet, and closing the gap with a weather tape. Similarly, the work site 10 is assembled so as to shield the outdoor portion 12 of the incinerator from the outside. However, the work site 10 only needs to be shielded to the extent that the dust generated during the dismantling work is not scattered by partitioning the inside and outside of the work site, and a secret that can maintain the interior at a certain level of negative pressure by a negative pressure machine described later. If it has the characteristics, it is not required until all the gaps are completely sealed. Note that the high chimney may be closed first by closing the opening with a sheet or the like, and the work place 10 may be assembled after the opening is lowered.

  The work place 10 is provided with a negative pressure machine 13. The negative pressure machine 13 is an exhaust device arranged outside the work place 10, and an intake port thereof is introduced into the work place 10. This negative pressure machine 13 has a combination of a pre-filter, a charcoal filter, and a hepa filter in accordance with the guidelines, and operates with an output that exhausts air corresponding to four times the volume of the work place 10 per hour. When the negative pressure machine 13 is operated, the air in the work place 10 is sucked out, and the work place 10 is maintained at a constant negative pressure. Also in this case, since air flows into the work place 10 from various gaps, the work place does not become deficient. Also, in dismantling work, a large amount of water is used to prevent dust scattering or washing with high-pressure water, etc., and if these enter the ground, they can cause environmental pollution. Laying and other waterproofing is applied.

  The incinerator to be dismantled varies depending on the site. For example, the incinerator shown in FIG. 2 has a flue 61, a smoke shower 62, a cyclone 63, an induction blower 64, a chimney 65, an incinerator main body 66, an ashing facility 67, and sewage. A processing facility 68 is provided, and for all these elements, residual ash and other deposits must be removed and the interior cleaned before dismantling.

  A preparation room 20 is provided at the entrance of the work place 10. The preparation room 20 has air showers and automats for the operator to remove residual ashes during work, changing rooms for workers to put on and take off protective clothing, other shelves with protective clothing and masks, etc. A material collection container, a table, and the like are provided, and the room may be divided into two or more rooms as shown in FIG. Each room and the entrance to the outside are partitioned by a door so that the work place 10 does not directly open to the outside.

  Removal of residual ash and other deposits is carried out manually by a worker wearing protective clothing or using an appropriate suction device. The residual ash collected here is packed in a flexible container (commonly known as a flexible container bag) and carried out to a waste disposal site. After that, each facility is cleaned by introducing high-pressure cleaning water. In the method of the present invention, a mist spraying step for the facility to be cleaned is provided before that.

  In the mist process, the mist generator 1 is introduced from an inspection port or the like of the work target plant, and the plant is filled with a large amount of acidic or alkaline mist and left for a predetermined time. Prior to this, a breakwater will be installed around the inspection port to prevent leakage of acid or alkaline water. In addition, it is desirable to check the curing equipment once again so that the chemical solution does not scatter outside the system. As described above, the work is performed with a waterproof sheet laid on the floor of the work place.

  Next, 20 to 40 L of a predetermined chemical solution is placed in the chemical solution tank 3 of the mist generator 1. This chemical solution is determined appropriately depending on the plant to be worked on or the deposits inside.For example, dilute sulfuric acid is used for environments such as clinker, rust, refractory brick base, metal surface, etc. An aqueous solution of sodium hydroxide (caustic soda) is used. When creating chemicals, confirm the properties using MSDS (Material Safety Data Sheet) and confirm the work procedure in advance. This chemical preparation work is carried out by wearing an airline mask. Further, after dilution of the chemical solution, a coloring agent such as food red is added to the aqueous solution at about 1 to 5%. In addition, the negative pressure machine 13 provided in the work place 10 is stopped during the dilution of the chemical solution or the mist spraying and during the standing time, and entry to the site is prohibited.

Next, the mist generator 1 is placed in the center of the plant, and an air pipe from an external compressor (not shown) is connected. At this time, the column 4 of the mist generator 1 is extended and the spray nozzle 5 is set to an appropriate height. Here, it is desirable that the height of the nozzle 5 be more than half the height inside the plant. Moreover, when the mist generator 1 whole does not enter from the inspection port etc. of the washing | cleaning object plant, the spray nozzle 5 uses the mist generator which can be attached or detached with respect to a main-body part, and arrange | positions only the spray nozzle 5 inside an installation. At the same time, a small blower 8 is installed inside the plant, and the internal air is convected with a weak output (for example, 10 to 60 m ³ / min). The mist generator 1 is operated after closing the inspection port into which the equipment is introduced, and mist is generated. The spraying time is about ^{3 to} 15 minutes per 1 m ³ , and the timer operation is performed by setting in advance. It is prohibited to enter the plant during mist generation and for 2 hours after stopping. FIG. 2 is an image diagram showing a state of the plant in which mist is generated.

  As a result, a large amount of mist generated in a large amount reaches all corners of the plant, soaks into the residue adhering to the inner wall of the plant, makes the structure brittle, and can be easily peeled off in a subsequent high-pressure water washing step. In addition, the leaving time after mist generation is at least about 1 to 3 hours. If the time is shorter than 1 hour, a large amount of mist still remains in the atmosphere and the worker is exposed to the chemical mist. There is an inconvenience that it is hard to fall.

  After being left for an appropriate period of time, the negative pressure machine 13 is operated to maintain the work space or the inside of the plant at a negative pressure, and as shown in FIG. 2, a high-pressure washing water nozzle 15 is introduced into the plant and a suction vehicle is installed at the bottom of the plant. Install suction hose from 50. Workers wearing chemical protective suits, protective caps, level 3 airline masks, chemical protective gloves, and chemical protective shoes enter the plant and spray high pressure water onto the plant inner wall to clean it. Here, the deposit on the inner wall of the plant is fragile due to mist, and is easily peeled off by blowing high-pressure water or flowing from above and removed from the inner wall of the plant. When the work is started by the colored mist, the inner wall of the plant is all colored, and the colorant is removed from the portion washed by the worker with high-pressure water. Therefore, the worker can easily identify the portion that has already been subjected to high-pressure cleaning and the portion that is not so, and can perform a reliable and leak-free cleaning operation. Moreover, since the part which the chemical | medical solution mist adheres can be identified easily, it can prevent that an operator touches an acidic or alkaline chemical | medical solution. Further, by checking the color of the protective clothing when entering the plant, it is possible to check whether the colored mist is still scattered in the atmosphere. If the color of the protective clothing is enough, go out and leave again for about 30 minutes to 1 hour.

  The waste water that has fallen to the bottom of the plant is collected by the suction wheel 50 from the suction hose. At this time, it is desirable to start suction after flowing a certain amount of high-pressure water so that the sprayed chemical solution is recovered in a sufficiently diluted state. The collected waste water is transported together with the suction wheel 50 to a water treatment plant where it is treated. In the plant, equipment such as the mist generator 1 and the blower 8 is also washed with high-pressure water so as to drop the attached chemical solution. When this cleaning process is completed, a drying period is provided as necessary, and then the plant is dismantled and carried out to the treatment plant. When the high pressure water cleaning and dismantling including sediment removal and mist processes are completed for all facilities, the curing facilities and preparation rooms are removed and the plant dismantling process is completed.

  In this way, by filling the chemical solution mist in the plant and soaking the chemical solution in the residue deposited and adhered to the inner wall of the plant and then performing high-pressure water washing, the residual contaminants can be removed easily and reliably. Therefore, the work labor can be reduced, and the decontamination process of the contaminated plant can be performed safely while maintaining the safety of workers and the surrounding environment at a high level. Moreover, since the contaminants adhering to the inner wall of the plant are wetted by the mist, ash is prevented from rising when high-pressure water is sprayed, and the work can be performed in a safe environment.

  Although the plant cleaning method, the plant dismantling method, and the mist generator used therefor have been described, the present invention is not limited to the above-described embodiments, and can be realized as various modifications. For example, in the above embodiment, acidic or alkaline chemical mist is used, but this may be configured to spray water that does not mix the chemical. The effect is less than when chemical mist is used, but by spraying water mist in advance to wet the deposits in the plant, the mist particles soak into the contaminated contaminants, making the structure brittle and easier with high-pressure water. Can be peeled off. Further, the mist generator is not limited to the above structure, and various known mist generators may be applied. Even in this case, it is desirable that at least the inner wall of the chemical solution tank is made of stainless steel for spraying the chemical solution. If the plant to be cleaned itself is small or the inspection port for accessing the inside is small, a small mist generator may be used, or the main body and the nozzle part as described above are not used. Thus, only the nozzle part may be installed in the plant.

  Moreover, said mist process is applicable also to asbestos removal work. That is, in the asbestos removal work, the mist generator 1 in which an appropriate anti-scattering agent is put is placed in the plant before the actual peeling work and sprayed with mist. In this case as well, the blower 8 is installed so that the air inside is convected. Although a commercially available chemical | medical agent can be used for a scattering prevention agent, For example, appropriate scattering prevention agents containing resin and emulsion, such as vinyl acetate, can be used. This eliminates the need for the operator to spray the anti-scattering agent on the entire surface of the plant by spraying, thereby reducing labor. Further, since the anti-scattering agent can be uniformly applied to a high position in the plant, the asbestos powder is reliably prevented from being scattered in the subsequent peeling step. In this case as well, after leaving for 2 hours or more, a worker wearing protective clothing enters the plant and works to remove asbestos and remove the asbestos while operating the negative pressure machine and maintaining the negative pressure inside the plant. Is collected by sucking it with an appropriate hopper means having a sealed space, for example, and transported to a treatment plant.

FIG. 4 is a list showing examples of details of the chemical mist with respect to the type of the plant to be cleaned and the thickness of the deposit to be removed. As shown in this figure, when the hardened clinker is adhered, when the clinker layer is about 3 mm, about 5% of dilute sulfuric acid is sprayed for about 3 minutes per 1 m ³ , and the clinker layer is As the thickness increases, the spray amount is increased. Similarly, when rust, refractory brick base, metal surface, asbestos (asbestos), oil, etc. are attached, spraying an appropriate amount using an appropriate agent will result in adhesion removal and hardening during washing with high-pressure water. It has been found to improve dramatically. In addition, in the case of clinker and rust, it has been proved by the applicant's experiment that the effect of removing the deposits is reduced below the amount shown in the table, and conversely the effect above the set amount cannot be expected even when the amount is increased. .

  The plant cleaning method, the demolition treatment method, and the mist generator according to the present invention can be suitably used in the construction industry, the demolition work business for dismantling incinerators, and other industrial waste treatment industries.

It is a figure which shows the structure of one Example of the mist generator concerning this invention. It is a figure which shows an example of the construction site of the plant washing | cleaning and demolition processing method of this invention. It is an image figure which shows the mode at the time of mist generation | occurrence | production. It is a figure which shows the detail of the use mist according to an object plant.

Explanation of symbols

1 Mist Generator 3 Liquid Tank 4 Strut 5 Spray Nozzle 6 Hose 10 Work Site 13 Negative Pressure Machine 20 Preparation Room

Claims (5)

A cleaning method for a plant, a step of collecting residues such as residual ash and metal powder in the plant, a step of filling the mist with the mist and leaving it for a predetermined time, and then supplying high-pressure water to the inner wall of the plant spraying and a step of washing, the step of filling the mist in said plant, a method of cleaning plant, characterized in Rukoto comprising the step of convection the mist to operate the blower in said plant.   The method according to claim 1, wherein the mist contains an acidic or alkaline chemical solution.   The method according to claim 1 or 2, wherein the mist contains a colorant. In the asbestos removal method for plant equipment that is provided with asbestos on the inner wall, a step of filling the mist mixed with an anti-scattering agent in the plant and leaving it for a predetermined time, and then a step of removing asbestos while keeping the inside of the plant at a negative pressure preparative comprising, the step of filling the mist in said plant, asbestos removal method comprising Rukoto comprising the step of convection the mist to operate the blower in said plant. Plant disassembly processing method characterized by comprising the steps of claim 1 to 4.

Images