Asbestos removal system and method for preventing backflow of contaminated air inside an asbestos removal work area

Abstract

The present invention provides an asbestos removal system and a method for preventing the backflow of contaminated air within an asbestos removal work area when the work area becomes positively pressurized. [Solution] The asbestos removal system 10 comprises an opening 12a provided in the outer wall 12 of a building where asbestos removal work is performed, a work area isolation sheet 14 with holes 14a that overlap the opening 12a of the outer wall 12, and a sheet-like asbestos collection filter 16 that is overlapped and placed over the work area isolation sheet 14 with holes 14a from inside the work area. In the asbestos removal system 10, the holes 14a are blocked by the asbestos collection filter 16, and the upper edge 16b of the asbestos collection filter 16 is fixed and attached to the work area isolation sheet 14. This prevents the scattering of asbestos.

Description

[[Technical Field]]

[0001] The present invention relates to an asbestos removal system that prevents backflow of contaminated air inside a work area, where the contaminated air inside an isolated enclosure leaks to the outside through security zones or fragile enclosure parts, which occurs during asbestos removal, and to a method for preventing backflow of contaminated air inside an asbestos removal work area. [[Background Art]]

[0002] In asbestos removal, isolated enclosure refers to an important scattering prevention measure in which the asbestos removal work area (isolated enclosure area) is completely sealed and blocked off with a vinyl sheet (plastic sheet) or the like to prevent asbestos from scattering (leaking) to the outside, thereby preventing asbestos from scattering to the outside. In particular, in the removal work of asbestos-containing sprayed materials corresponding to asbestos removal work level 1, it is necessary to maintain a negative pressure state in the work area where the air pressure in the work area is kept lower than that outside by operating a negative pressure dust collector (Fig. 4(a)). When strong wind or the like rages while the negative pressure dust collector is stopped due to a failure or other reasons, the asbestos removal work area becomes a positive pressure state (Fig. 4(b)). For example, when the negative pressure dust collector is stopped, and external air flows into the work area through the exhaust port of the negative pressure dust collector due to strong external wind, the work area becomes a positive pressure state. When the work area becomes a positive pressure state, the contaminated air inside the work area flows out to the outside through the security zone that serves as the entrance and exit of the work area (Fig. 4(b)), poorly overlapped portions of vinyl sheets, and fragile enclosure parts such as joints between the vinyl sheet and the building structure (not shown). That is, backflow of the contaminated air inside the asbestos removal work area occurs. In order to prevent asbestos from scattering to the outside, it has been necessary to prevent the occurrence of backflow of contaminated air inside the asbestos removal work area. In the present application, the failure of the negative pressure dust collector and other causes include failures of the device (equipment), power outages, unplugged outlets (when the power plug is pulled out from the outlet), and the like. Furthermore, strong winds refer to strong external winds that flow back into the exhaust port of the negative pressure dust removal device (dust collection and exhaust device). This is an extremely dangerous factor in asbestos demolition and repair sites, as it can lead to the destruction of negative pressure isolation and curing, i.e., the pressure in the isolated space becoming positive. In chimney asbestos insulation removal work, this refers to the wind pressure generated when the insulation blocking the chimney falls all at once. The air inside the chimney is suddenly pushed out through the opening at the bottom of the chimney and released into the work area below the chimney with great wind pressure. This wind pressure causes the work area to become positive pressure, making it difficult for the negative pressure dust removal device installed in the work area to maintain a negative pressure state in that area.

[0003] Conventionally, chimney asbestos removal work protection systems have been provided to prevent the backflow of contaminated air from the security zone into the work area under positive pressure conditions in the asbestos removal work area (for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-8687 [Overview of the project] [Problems that the invention aims to solve]

[0005] The chimney asbestos removal work protection system described in Patent Document 1 comprises a negative pressure dust removal device that creates a negative pressure state in the work area, an airflow blocking unit that prevents the airflow in the positive pressure state of the work area from being released to the outside, and a wind pressure buffering protection unit that causes the protective sheet forming the work area to inflate outwards when the work area becomes positive pressure. As a result, even when the work area becomes positive pressure, the wind pressure of the airflow can be buffered, and the airflow (contaminated air) in the positive pressure state of the work area can be prevented from entering the security zone and being released to the outside. In addition, the negative pressure dust removal device can restore the negative pressure state of the work area.

[0006] The chimney asbestos removal work protection system described in Patent Document 1 restores a negative pressure state in the work area using a negative pressure dust removal device. The negative pressure dust removal device maintains a negative pressure state in the work area where asbestos and hazardous dust are generated, preventing contaminated air from leaking to the outside. The negative pressure dust removal device draws in air from the work area, filters it with a HEPA filter or the like to purify it, and discharges it to the outside. When the negative pressure dust removal device is in operation, purified air is discharged to the outside, and outside air constantly flows into the work area through the security zone (Figure 4(a)). This prevents air containing asbestos from leaking out of the work area. However, if the negative pressure dust removal system malfunctions or stops operating, and strong winds blow, the work area will become positively pressurized. When the work area becomes positively pressurized, contaminated air from inside the work area will flow back in through security zones and vulnerable areas, causing the air inside the work area to leak out (Figure 4(b)).

[0007] The present invention aims to solve the above problems and to provide an asbestos removal system and a method for preventing the backflow of contaminated air inside an asbestos removal work area when the work area becomes under positive pressure. [Means for solving the problem]

[0008] The asbestos removal system of the present invention comprises an opening provided in the exterior wall of a building where asbestos removal work is to be performed, a work area isolation sheet with holes that overlaps the opening in the exterior wall, and a sheet-like asbestos collection filter that is placed over the work area isolation sheet with holes from inside the work area, with the asbestos collection filter blocking the holes and the upper edge of the asbestos collection filter only It is designed to be fixed and attached to a protective sheet to isolate the work area.

[0009] The present invention provides a method for preventing the backflow of contaminated air inside an asbestos removal work area. This method involves creating an opening in the outer wall of the building where asbestos removal work is performed, making a hole in a work area isolation sheet that overlaps with the opening in the outer wall, and placing a sheet-like asbestos collection filter over the work area isolation sheet with the hole from inside the work area, blocking the hole with the asbestos collection filter and the upper edge of the asbestos collection filter. only It is designed to be fixed and attached to a protective sheet to isolate the work area. [Effects of the Invention]

[0010] According to the present invention, when the asbestos removal work area is under positive pressure, the air in the work area is discharged to the outside through an opening in the outer wall and is purified by an asbestos collection filter that blocks the opening in the outer wall. By discharging the air from the work area to the outside through an opening in the outer wall, the backflow of contaminated air inside the asbestos removal work area can be prevented, and the scattering of asbestos can be prevented. [Brief explanation of the drawing]

[0011] [Figure 1] This is a diagram illustrating the asbestos removal system of the present invention (a diagram showing the work area under positive pressure). [Figure 2] Figure 1 shows the state of the asbestos collection filter when the work area is under negative pressure. [Figure 3] This diagram shows the airflow in the work area of ​​the asbestos removal system of the present invention. [Figure 4] This diagram illustrates the airflow within a work area during conventional asbestos removal operations. [Modes for carrying out the invention]

[0012] This invention aims to prevent the scattering of asbestos fibers during asbestos removal work. [Examples]

[0013] The present invention's asbestos removal system and method for preventing the backflow of contaminated air inside an asbestos removal work area will be explained with reference to the figures. Figure 1 shows the asbestos removal system of the present invention. Figure (a) is a cross-sectional view of the exterior wall of a building, a work area isolation sheet, and an asbestos collection filter in a positive-pressure work area, and Figure (b) is a front view of the asbestos collection filter in Figure (a) as seen from inside the work area. Figure 2 shows the state of the asbestos collection filter when the work area in Figure 1 is under negative pressure. Figure (a) is a cross-sectional view of the building's exterior wall, work area isolation sheet, and asbestos collection filter under negative pressure in the work area, and Figure (b) is a front view of the asbestos collection filter in Figure (a) as seen from inside the work area. Figure 3 shows the airflow in the work area in the asbestos removal system of the present invention, where Figure (a) shows the airflow in the work area when it is under negative pressure, and Figure (b) shows the airflow in the work area when it is under positive pressure. The asbestos collection filters in Figures 1 to 3 are HEPA filters (High Efficiency Particulate Air Filters, filters that capture 99.97% or more of 0.3 micrometer (μm) particles).

[0014] The asbestos removal system 10 of the present invention comprises an opening 12a provided in the outer wall 12 of a building where asbestos removal work is performed, a work area isolation sheet 14 having holes 14a that overlap the opening 12a of the outer wall 12, and a sheet-like asbestos collection filter 16 that is overlapped and placed over the work area isolation sheet 14 with holes 14a from inside the work area. In the asbestos removal system 10, the holes 14a are blocked by the asbestos collection filter 16, and the upper edge 16b of the asbestos collection filter 16 is fixed and attached to the work area isolation sheet 14.

[0015] The opening 12a is provided in the outer wall 12 of a building. For example, it is an opening in the outer wall formed by a window of the building or a tool. In FIG. 3, the opening 12a is provided near the ceiling of the work area (FIG. 3), but the present invention is not limited thereto. When the work area is in a positive pressure state (a state where the air pressure in the work area is higher than that of outside air), the airflow in the work area flows out to the outside through either the opening at a low position or the opening at a high position. When the work area is in a positive pressure state and the air in the work area is warm, the opening 12a is preferably provided near the ceiling. By providing the opening 12a near the ceiling, hot air and contaminated air (air containing asbestos) in the work area can be efficiently discharged to the outside through the opening 12a (FIG. 3(b)).

[0016] The work area isolation curing sheet 14 is a plastic sheet (vinyl sheet) used in asbestos removal work, and is for curing and isolating the work area. The hole 14a of the work area isolation curing sheet 14 is formed at a position overlapping the opening 12a of the outer wall 12. When the work area is in a positive pressure state, the air in the work area flows out to the outside through the opening 12a and the hole 14a (FIG. 1, FIG. 3(b)). When the work area is in a negative pressure state, outside air flows into the work area through the opening 12a and the hole 14a (FIG. 2, FIG. 3(a)). In addition, in FIG. 1 and FIG. 2, the size of the hole 14a of the work area isolation curing sheet 14 is the same as that of the opening 12a of the outer wall 12, but the present invention is not limited thereto. The size of the hole 14a may be formed smaller than that of the opening 12a.

[0017] In FIG. 1 and FIG. 3(b), the work area is in a positive pressure state, and the air in the work area flows out to the outside through the opening 12a and the hole 14a. When the air in the work area flows out to the outside, the sheet-shaped asbestos collection filter 16 (FIG. 1) abuts against the work area isolation curing sheet 14 so as to block the hole 14a by the air (airflow) in the work area (FIG. 1, FIG. 3(b)). The air in the work area flowing out to the outside passes through the asbestos collection filter 16, becomes cleaned air, and is discharged to the outside (FIG. 1, FIG. 3(b)).

[0018] On the other hand, in FIGS. 2 and 3(a), the working area is in a negative pressure state, and outside air flows into the working area through the opening 12a and the hole 14a. The upper side 16b of the sheet-shaped asbestos collection filter 16 is fixedly attached to the work area isolation curing sheet 14 on which the asbestos collection filter 16 is overlaid (FIG. 2). When the working area is in a negative pressure state, outside air flows into the working area through the opening 12a and the hole 14a, and at the same time, the asbestos collection filter 16 is blown up with the upper side 16b fixedly attached to the work area isolation curing sheet 14 as a fulcrum (FIGS. 2 and 3(a)).

[0019] In FIGS. 1 to 3, the opening 12a and the hole 14a are blocked by the central portion 16a of the asbestos collection filter 16. The portion of the asbestos collection filter 16 other than the central portion 16a abuts against the work area isolation curing sheet 14. When the working area is in a positive pressure state, by bringing the asbestos collection filter 16 into contact with the work area isolation curing sheet 14 (FIGS. 1 and 3(b)), it is possible to prevent air (airflow) in the working area from entering through the gap between the asbestos collection filter 16 and the work area isolation curing sheet 14 and being discharged to the outside through the opening 12a and the hole 14a (FIG. 1). Furthermore, by overlaying the asbestos collection filter 16 on the hole 14a of the work area isolation curing sheet 14, it is possible to prevent asbestos from scattering to the outside from the opening 12a of the outer wall 12. It should be noted that it is preferable to use an asbestos collection filter 16 that is wider (larger) than the dimension of the hole 14a of the work area isolation curing sheet 14 (FIGS. 1 to 3). By covering the hole 14a of the work area isolation curing sheet 14 with a filter that is slightly wider (slightly larger) than the dimension of the hole 14a of the work area isolation curing sheet 14, it is possible to prevent asbestos in the working area from scattering to the outside through the opening 12a and the hole 14a after air (airflow) in the working area enters through the gap between the asbestos collection filter 16 and the work area isolation curing sheet 14.

[0020] In Figures 1 to 3, masking tape 18 is used to fix and attach the asbestos collection filter 16 to the work area isolation sheet 14, but this is not the only method. However, the fixing and attachment method for the asbestos collection filter 16 should not create a gap between the work area isolation sheet 14 and the asbestos collection filter 16 when they are placed on top of each other.

[0021] The present invention provides a method for preventing the backflow of contaminated air inside an asbestos removal work area, using the above-described asbestos removal system 10. An opening 12a is provided in the outer wall 12 of the building where asbestos removal work is performed, and a hole 14a is provided in the work area isolation sheet 14 that overlaps with the opening 12a in the outer wall 12. A sheet-like asbestos collection filter 16 is placed over the work area isolation sheet 14 with the hole 14a from inside the work area, blocking the hole 14a with the asbestos collection filter 16, and the upper edge 16b of the asbestos collection filter 16 is fixed and attached to the work area isolation sheet 14, thereby preventing the backflow of contaminated air inside the work area. When the asbestos removal system 10 is used to discharge air from the work area through the opening 12a in the outer wall while the work area is under positive pressure, the air (airflow) from the work area does not flow towards the security zone or vulnerable protected areas (not shown) (Figure 3(b)). In other words, backflow of contaminated air from inside the work area does not occur, and the scattering of asbestos can be prevented.

[0022] According to the present invention, when the operation of the negative pressure dust removal device is stopped due to a malfunction or the like, and strong winds or the like are blowing, causing the work area to become positively pressurized, the air in the work area is discharged to the outside through the opening 12a in the outer wall 12 of the building, and does not flow out to the outside through security zones or vulnerable protected areas (Figure 3(b)). The present invention provides an asbestos removal system and a method for preventing the backflow of contaminated air inside an asbestos removal work area. In the removal of asbestos-containing sprayed materials that are prone to scattering and fall under asbestos removal work level 1, even if the work area becomes positively pressurized due to a malfunction of the negative pressure dust removal device or strong winds, etc., the system can prevent contaminated air from leaking out of the work area through security zones or vulnerable protective areas (backflow of air inside the work area) to the outside. [Explanation of Symbols]

[0023] 10 Asbestos Removal Systems 12. Exterior walls of buildings 12a opening 14. Work area isolation sheet 14a hole 16. Asbestos collection filter 16b Top edge

Claims

1. An asbestos removal system comprising an opening in the exterior wall of a building where asbestos removal work is to be carried out, a work area isolation sheet with holes that overlap the opening in the exterior wall, and a sheet-like asbestos collection filter that is placed over the work area isolation sheet with holes from inside the work area, wherein the holes are blocked by the asbestos collection filter and only the upper edge of the asbestos collection filter is fixed and attached to the work area isolation sheet.

2. A method for preventing the backflow of contaminated air inside an asbestos removal work area, characterized by providing an opening in the exterior wall of a building where asbestos removal work is to be carried out, providing a hole in a work area isolation sheet that overlaps with the opening in the exterior wall, covering the work area isolation sheet with a sheet-like asbestos collection filter from inside the work area, blocking the hole with the asbestos collection filter, and fixing and attaching only the upper edge of the asbestos collection filter to the work area isolation sheet.

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