JP7769542B2 - Hot work chamber and hot work method - Google Patents

Description

This disclosure relates to a fire work chamber and a fire work method.

For example, the inner surface of a liquefied gas storage tank, which stores liquefied gas such as LNG at extremely low temperatures, is made of metal (see, for example, Patent Document 1 below). Repairing such an inner surface made of metal requires hot work that generates sparks, such as drilling or grinding. However, inside a liquefied gas storage tank, there is a possibility that the liquefied gas may vaporize and generate flammable gas. When performing hot work in a work area where flammable gas is present, the flammable gas must be evacuated from the work area beforehand.

Japanese Patent Application Laid-Open No. 2003-227596

However, there are cases where it is not possible to completely evacuate flammable gas from the work area, such as when repairing a surface from which flammable gas is leaking. In such cases, hot work cannot be performed. Therefore, the purpose of this disclosure is to provide a hot work chamber that allows safe hot work to be performed even when there is a possibility of flammable gas being present in the work area.

A hot work chamber according to one aspect of the present disclosure comprises an opening frame that fits tightly against the hot work surface, a transparent case that covers the area enclosed by the opening frame, a right glove attachment port located on the surface of the case for donning a right glove, a left glove attachment port located on the surface of the case for donning a left glove, an inlet to which an injection hose can be connected to inject gas into the case, and an outlet to which an exhaust hose can be connected to exhaust gas from the case.

The above configuration makes it possible to provide a fire work chamber that allows safe fire work to be carried out even when there is a possibility of flammable gas being present in the work area.

FIG. 1 is a plan view of a hot work chamber. FIG. 2 is a front view of the hot work chamber. FIG. 3 is a right side view of the hot work chamber. 4 is a cross-sectional view taken along the line IV-IV in FIG. FIG. 5 is an enlarged cross-sectional view of the glove opening. FIG. 6 is a flow chart of the hot work method.

<Hot work chamber>
A fire operation chamber 100 according to an embodiment of the present disclosure will now be described. Figure 1 is a plan view of the fire operation chamber 100. Figure 2 is a front view of the fire operation chamber 100, showing the fire operation chamber 100 as viewed from below the paper surface of Figure 1. Figure 3 is a right side view of the fire operation chamber 100, showing the fire operation chamber 100 as viewed from the right side of the paper surface of Figure 1. Figure 4 is a cross-sectional view taken along the line IV-IV in Figure 1.

The hot work chamber 100 of this embodiment is a device used when performing hot work on a work surface 101. Note that "hot work" refers to work that generates sparks, such as drilling or grinding. The work surface 101 on which hot work is performed in this embodiment is made of a magnetic metal material. Furthermore, the work surface 101 in this embodiment is a horizontal surface. However, the work surface 101 is not limited to the above.

As shown in FIG. 1, the hot work chamber 100 according to this embodiment includes an opening frame 10, a case 20, glove donning ports 31 and 32, an inlet 40, an outlet 50, a glove presser cap 60, an anchor 70, and a fixing band 80. These components will be described in order below.

The opening frame 10 is the part that comes into close contact with the work surface 101 used in hot work. As shown in Figure 1, the opening frame 10 of this embodiment is formed in the shape of a pentagonal frame. As shown in Figure 4, the opening frame 10 includes a surface-contacting layer 11, which is the part that comes into contact with the work surface 101, and a non-surface-contacting layer 12, which is the part that is located between the surface-contacting layer 11 and the case 20. Note that the opening frame 10 of this embodiment is a separate member from the case 20, but the case 20 may come into direct contact with the work surface 101. In this case, the part of the case 20 that comes into contact with the work surface 101 becomes the opening frame 10.

The surface-contacting layer 11 has a lower hardness than the case 20. In other words, the surface-contacting layer 11 is more easily deformed than the case 20. As an example, the surface-contacting layer 11 is made of CR (chloroprene rubber) sponge. The non-surface-contacting layer 12 may also be made of the same material as the case 20. Because the surface-contacting layer 11 has a relatively low hardness, the opening frame 10 can be tightly attached to the work surface 101 even if the work surface 101 is slightly uneven. Note that although the entire opening frame 10 in this embodiment is located on the same plane, the entire opening frame 10 may be curved in accordance with the shape of the work surface 101.

The case 20 is a member that covers the area surrounded by the opening frame 10. The case 20 is transparent, allowing the interior to be seen from the outside. In this embodiment, the case 20 is made of acrylic material, as an example. However, the material of the case 20 is not limited to this. As shown in FIG. 1, the case 20 is formed in a pentagonal shape in a plan view. The case 20 includes a right front surface 21, a left front surface 22, a right side surface 23, a left side surface 24, a back surface 25, and a top surface 26. As shown in FIG. 4, the surface of the case 20 opposite the top surface 26 is open. In other words, the case 20 is open on the work surface 101 side.

In this embodiment, the right front surface 21, left front surface 22, right side surface 23, left side surface 24, and back surface 25 of the case 20 extend vertically upward from the opening frame 10, and the top surface 26 extends horizontally. Furthermore, these surfaces 21 to 26 are all flat. Although the case 20 of this embodiment has the shape described above, the case 20 may have a shape different from the above. For example, the case 20 may be rectangular in a plan view, and the top surface 26 may be inclined relative to the horizontal. Furthermore, the case 20 may be hemispherical.

The glove openings 31 and 32 are where the gloves 102 are donned. The gloves 102 are made of rubber. The glove openings 31 and 32 include a right glove opening 31 for donning the right glove 102 and a left glove opening 32 for donning the left glove 102. The right glove opening 31 further has a first right glove opening 33 and a second right glove opening 34. Similarly, the left glove opening 32 has a first left glove opening 35 and a second left glove opening 36. Of these, the first right glove opening 33 and the first left glove opening 35 form a pair, and the second right glove opening 34 and the second left glove opening 36 form a pair.

The glove donning openings 31 and 32 are located on the surface of the case 20. Specifically, the first right glove donning opening 33 is located on the right front surface 21, and the first left glove donning opening 35 is located on the left front surface 22. The second right glove donning opening 34 and the second left glove donning opening 36 are both located on the top surface 26.

Figure 5 is an enlarged cross-sectional view of the glove donning openings 31 and 32. As shown in Figure 5, the glove donning openings 31 and 32 are cylindrical and connected to the interior of the case 20. The glove donning openings 31 and 32 have threads formed on their outer surfaces. As shown in Figure 2, the central axis of the second right glove donning opening 34 and the central axis of the second left glove donning opening 36 are parallel. In contrast, as shown in Figure 1, the central axis of the first right glove donning opening 33 and the central axis of the first left glove donning opening 35 are not parallel. Specifically, the angle α formed by the central axis of the first right glove donning opening 33 and the central axis of the first left glove donning opening 35 is between 30 degrees and 90 degrees.

The injection port 40 is a connection port to which an injection hose 103 can be connected, which injects gas into the case 20. In this embodiment, an inert gas is injected into the case 20 through the injection port 40. The injection port 40 is located on the back surface 25 of the case 20 and is connected to the interior of the case 20. However, the injection port 40 may be located on a surface other than the back surface 25 of the case 20. Also, as shown in FIG. 3, the injection port 40 is located in the lower part of the case 20. The injection hose 103 may be connected to the injection port 40 via a valve, or may be connected directly to the injection port 40.

The exhaust port 50 is a connection port to which an exhaust hose 104 can be connected, which exhausts gas from inside the case 20. As described above, in this embodiment, inert gas is injected into the case 20 through the inlet 40, causing the gas inside the case 20 to be exhausted to the outside of the case 20 through the exhaust port 50. The exhaust port 50 is located on the right side surface 23 of the case 20 and is connected to the interior of the case 20. However, the exhaust port 50 may be located on a surface other than the right side surface 23 of the case 20. Also, as shown in FIG. 3, the exhaust port 50 is located in the upper part of the case 20. In other words, the position of the exhaust port 50 is higher than the position of the inlet 40. The exhaust hose 104 may be connected to the exhaust port 50 via a valve, or may be connected directly to the exhaust port 50.

The glove presser cap 60 is detachably attached to the glove donning openings 31, 32 and is used to secure the glove 102 to the glove donning openings 31, 32. As shown in Figure 5, the glove presser cap 60 includes a main body 61, a flange 62, and a gasket 63. The main body 61 is cylindrical, and its inner surface is formed with threads that mate with the threads of the glove donning openings 31, 32. The flange 62 is annular, continues from the end of the main body 61, and is located radially inward of the main body 61. The gasket 63 is annular, and is located on the surface of the flange 62 facing the end surface of the glove donning openings 31, 32.

To secure the glove 102 in the glove donning openings 31, 32, as shown in FIG. 5, the glove 102 is inserted into the glove donning openings 31, 32, the end of the glove 102 is folded outward, and the folded portion is positioned outside the glove donning openings 31, 32. In this state, the glove presser cap 60 is fastened to the glove donning openings 31, 32. This sandwiches the glove 102 between the packing 63 and the end face of the glove donning openings 31, 32, securing the glove 102 to the glove donning openings 31, 32. As shown in FIG. 1, the glove presser cap 60 includes a right glove presser cap 64 for placing the right glove 102 in the right glove donning opening 31, and a left glove presser cap 65 for placing the left glove 102 in the left glove donning opening 32.

The anchor 70 is a member that can be attracted to the work surface 101. In this embodiment, the anchor 70 has a magnet, and the work surface 101 is magnetic. Therefore, the anchor 70 is magnetically attracted to the work surface 101. The anchor 70 may also be a so-called suction cup. As shown in FIG. 2, the anchor 70 in this embodiment includes an anchor body 71 having a magnet and a locking portion 72 fixed to the anchor body 71. Also, as shown in FIG. 1, the hot work chamber 100 in this embodiment has four anchors 70. Two of these anchors 70 are located to the right of the case 20. The other two anchors 70 are located to the left of the case 20.

The fixing bands 80 are bands that span between the anchors 70. As shown in Figure 1, the fire operation chamber 100 according to this embodiment is equipped with two fixing bands 80. The ends of each fixing band 80 are engaged with the engaging portions 72 of the anchors 70. Each fixing band 80 spans between an anchor 70 located to the right of the case 20 and an anchor 70 located to the left of the case 20. At this time, each fixing band 80 passes through the top surface 26, which corresponds to the upper surface of the case 20, and presses the case 20 downward via the upper surface of the case 20. As a result, the opening frame 10 is in close contact with the work surface 101, and the entire fire operation chamber 100 is fixed to the work surface 101.

<How to work around fire>
Next, a description will be given of a method for working with fire according to this embodiment. The method for working with fire according to this embodiment is carried out using the above-described fire work chamber 100. Figure 6 is a flow chart of the method for working with fire.

As shown in Figure 6, the worker first secures the hot work chamber 100 to the work surface 101 (step S1). As described above, the anchors 70 are magnetically attached to the work surface 101, passed through the top surface of the case 20, and the fixing bands 80 are placed between the anchors 70, thereby securing the hot work chamber 100 to the work surface 101.

Next, the worker puts on the right glove 102 in the right glove donning opening 31 and the left glove 102 in the left glove donning opening 32 (step S2). As described above, the worker can put the gloves 102 in the glove donning openings 31 and 32 by using the glove holder cap 60 to sandwich the glove 102 between the glove holder cap 60 and the glove donning openings 31 and 32. Note that it is not necessary to put gloves 102 in all of the glove donning openings 31 and 32.

For example, gloves 102 may be worn in the first right glove donning opening 33 and the first left glove donning opening 35, and the second right glove donning opening 34 and the second left glove donning opening 36 may be closed. Alternatively, gloves 102 may be worn in the second right glove donning opening 34 and the second left glove donning opening 36, and the first right glove donning opening 33 and the first left glove donning opening 35 may be closed with gloves 102. To close the glove donning openings 31 and 32, a lid-shaped opening-closing cap may be fastened to the glove donning openings 31 and 32 instead of the glove presser cap 60.

Next, the operator injects inert gas into the case 20 through the inlet 40 while discharging the gas from the case 20 through the outlet 50 (step S3). By performing step S2 described above, the inside of the case 20 is sealed. In this state, by performing step S3, the flammable gas inside the case 20 and the oxygen required for combustion of the flammable gas can be discharged to the outside of the case 20.

Next, the worker performs hot work on the area of the work surface 101 covered by the case 20 using the right glove 102 and the left glove 102 (step S4). This step S4 is performed while performing step S3, that is, while injecting inert gas into the case 20 through the inlet 40 and discharging gas from the case 20 through the outlet 50. By performing step S3, flammable gas and oxygen are discharged from the case 20, and the flammable gas will not ignite even if hot work is performed inside the case 20. Note that even if flammable gas leaks from the part of the work surface 101 covered by the case 20, the flammable gas will not ignite inside the case 20 because there is at least almost no oxygen inside the case 20.

<Effects of the embodiment>
As described above, the fire work chamber of this embodiment comprises an opening frame that fits tightly against the work surface for fire work, a transparent case that covers the area surrounded by the opening frame, a right glove attachment port located on the surface of the case for putting on a right glove, a left glove attachment port located on the surface of the case for putting on a left glove, an inlet to which an injection hose can be connected to inject gas into the case, and an outlet to which an exhaust hose can be connected to exhaust gas from the case.

With this configuration, if you inject inert gas into the case through the inlet while discharging the gas from the case through the outlet, and then perform hot work on the area of the work surface covered by the case through the right and left gloves, the flammable gas will not ignite during the hot work. Therefore, even if there is a possibility of flammable gas being present in the work area, you can perform hot work safely.

Furthermore, in the hot work chamber according to this embodiment, the angle formed by the central axis of the right glove donning opening and the central axis of the left glove donning opening is between 30 degrees and 90 degrees.

This configuration makes it easier for the worker to bring the tips of their right and left hands closer together, improving the ease of working with fire.

In addition, in the hot work chamber of this embodiment, the right glove donning opening includes a first right glove donning opening and a second right glove donning opening, and the left glove donning opening includes a first left glove donning opening and a second left glove donning opening.

With this configuration, workers can perform fire work using the gloves positioned in the most appropriate position for the work, depending on the location and type of fire work being performed. This improves the ease with which workers can perform fire work.

In addition, in the fire operation chamber of this embodiment, the portion of the opening frame that comes into contact with the work surface has a lower hardness than the case.

With this configuration, the portion of the opening frame that comes into contact with the work surface deforms to fit the shape of the work surface, allowing the opening frame to fit tightly against the work surface.

Furthermore, in the fire work chamber of this embodiment, the position of the exhaust port is higher than the position of the inlet.

With this configuration, when inert gas is injected into the case through the inlet and air or flammable gas with a lower specific gravity than the inert gas inside the case is discharged through the outlet, the air or flammable gas can be efficiently discharged from inside the case.

The hot work chamber according to this embodiment also includes a right glove holder cap that is detachable from the right glove donning opening and that sandwiches the right glove between the right glove donning opening and the cap to attach the right glove to the right glove donning opening, and a left glove holder cap that is detachable from the left glove donning opening and that sandwiches the left glove between the left glove donning opening and the cap to attach the left glove to the left glove donning opening.

This configuration allows gloves to be easily put on without leaving any gaps between the right and left glove openings and the gloves.

The hot work chamber of this embodiment also includes multiple anchors that are magnetically attached to the work surface, and a fixing band that passes through the top surface of the case and spans between the multiple anchors.

This configuration allows the hot work chamber to be easily secured to a work surface using anchors and fixing bands.

In addition, the hot work method according to this embodiment involves fixing the hot work chamber to the work surface, putting a right glove into the right glove opening and a left glove into the left glove opening, injecting inert gas into the case through the inlet while discharging the gas from the case through the outlet, and performing hot work on the area of the work surface covered by the case through the right glove and the left glove.

This method prevents flammable gases from igniting during hot work. Therefore, hot work can be carried out safely even if there is a possibility of flammable gases being present in the work area.

10 Opening frame 20 Case 31 Right glove donning port 32 Left glove donning port 33 First right glove donning port 34 Second right glove donning port 35 First left glove donning port 36 Second left glove donning port 40 Inlet 50 Outlet 60 Glove holder cap 64 Right glove holder cap 65 Left glove holder cap 70 Anchor 80 Fixing band 100 Hot work chamber 101 Work surface 102 Gloves 103 Inlet hose 104 Outlet hose

Claims (6)

An opening frame that is in close contact with the work surface for hot work;
a transparent case that covers an area surrounded by the opening frame , including a portion from which the flammable gas leaks ;
a right glove insertion port located on the surface of the case for inserting a right glove;
a left glove opening located on the surface of the case for putting on a left glove;
an injection port to which an injection hose for injecting an inert gas into the case can be connected;
an exhaust port to which an exhaust hose for exhausting gas from the case can be connected;
a fixing band that presses the case against the opening frame to bring the opening frame into close contact with the work surface ,
a portion of the opening frame that contacts the work surface has a lower hardness than the case;
A hot work chamber , wherein the outlet is located higher than the inlet . The hot work chamber of claim 1, wherein the angle between the central axis of the right glove opening and the central axis of the left glove opening is greater than or equal to 30 degrees and less than or equal to 90 degrees. the right glove opening includes a first right glove opening and a second right glove opening;
3. The hot work chamber according to claim 1, wherein the left glove opening includes a first left glove opening and a second left glove opening. a right glove holder cap that is detachably attached to the right glove donning opening and that sandwiches the right glove between the right glove donning opening and the right glove is put into the right glove donning opening;
4. The hot work chamber according to claim 1, further comprising a left glove holder cap that is detachable from the left glove donning opening and that sandwiches the left glove between the left glove donning opening and the left glove to be donned in the left glove donning opening. the work surface is magnetic;
further comprising a plurality of anchors magnetically attached to the work surface;
5. The hot work chamber according to claim 1 , wherein the fixing band passes through the upper surface of the case and bridges between the plurality of anchors. 6. A method for hot work, comprising: fixing a hot work chamber according to claim 1 to a work surface; putting a right glove into the right glove opening and a left glove into the left glove opening; injecting inert gas into the case through the inlet while discharging gas from the case through the outlet; and performing hot work on an area of the work surface covered by the case through the right glove and the left glove.