JPH0350941B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a contaminated air diffusion prevention device, and particularly to a contaminated air diffusion prevention device suitable for preventing the diffusion of contaminated air to the surroundings and effectively discharging it. Regarding equipment.

[Conventional technology]

Conventionally, as this type of contaminated air diffusion prevention device, as shown in FIG. 5 and FIG.
There is a device disclosed in No. 159082.

This device has a pair of hollow face walls 51a, 51b facing each other around a pollution source 50.
The tops of b are connected by a suction hood 55. Air curtain blowers 52a and 52b are installed inside the face walls 51a and 51b, respectively. At one end of each of the face walls 51a and 51b, vertically elongated air outlets 53a and 53b of the air curtain are provided.
At the other end, vertically elongated suction ports 54a and 54b are provided, respectively. The air outlet 53a of one side wall 51a is connected to the inlet 54b of the other side wall 51b, and the inlet 54a of the side wall 51a is connected to the air outlet 5 of the side wall 51b.
3b, respectively. With the above configuration, when the blowers 52a and 52b are operated, the face wall 5
In the open parts 56a and 56b before and after 1a and 51b,
Cross-flow air curtains 57a, 57 facing oppositely to each other
b is formed to prevent the spread of contaminated air from the pollution source 50. Cross-flow air curtains 57a, 57
When an exhaust fan (not shown) connected to the suction hood 55 is operated in a state where b is formed, the rising airflow 58 from the pollution source 50 is caused by the coupled action of the opposing crossflow air curtains 57a and 57b. A twisted artificial coil 59 is formed, and the center of the rising air current 58 is converged into a twisted thread.
Due to the effect of the artificial coil 59, contaminated air can be exhausted within a narrow range without being diffused to the outside.

However, in this device, the air curtain outlet 53
a, 53b and the suction ports 54a, 54b are the face wall 51
a and 51b, so when the pollution source 50 is large (for example, about 10 m), the face wall 51
a and 51b become very large structures, making it unsuitable for application to large-sized devices.

In addition, the distance L between the pollution source 50 and the suction hood 55 cannot be adjusted due to the fixed structure.
When the size of the coil 59 increases, there is a problem that it is difficult to induce the generation of the artificial coil 59 if the distance L remains large.

[Problem that the invention seeks to solve]

The present invention overcomes the drawbacks of the prior art, and even when the pollution source becomes large, the structure having the air curtain outlet and inlet does not become too large, and the distance between the pollution source and the suction hood is long. To provide a contaminated air diffusion prevention device that easily induces the generation of artificial coils.

[Means for solving problems]

In the present invention, an air curtain outlet and an air curtain inlet are assembled into a single columnar duct, and one outlet of the columnar duct faces the inlet of the other columnar duct. At least three columnar ducts are arranged upright, a blower is installed separately for supplying and suctioning pressurized air to these columnar ducts, and a contaminated air suction hood is installed in the center of the group of columnar ducts. This contaminated air suction hood can be raised and lowered in the vertical direction, and a plurality of directional suction holes are provided in the contaminated air suction hood so that the suction direction is the same as the suction port of the columnar duct. It is characterized by having been provided.

[Effect]

At least three columnar ducts are placed upright around the pollution source, and the air curtain outlet and inlet in each columnar duct are arranged to face each other. Even in the case of large pollution sources with long spacing, a continuous spiral cross-flow air curtain can be formed. In addition, the suction hood can be moved up and down, so even in the case of a large pollution source where the distance between the suction hood and the pollution source is long, the suction hood can be moved close to the pollution source at the start of operation to prevent suction. Negative pressure acts strongly, making it easier to induce artificial coiling.

Furthermore, by aligning the opening direction of the multiple suction holes in the suction hood with the direction of the inlet of the cross-flow air curtain, the winding speed of the artificial winding is accelerated, the rising air is focused into a strand, and the contaminated air is transferred to the cross-flow air. It can be completely shielded by two types of airflow: curtains and artificial tufts.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is a side configuration diagram of one embodiment of the present invention;
The figure is a plan cross-sectional configuration diagram of FIG. 1, and FIG. 3 is a side cross-sectional view of the suction hood according to the present embodiment.

In this embodiment, four columnar ducts 20 are placed upright on a mounting surface 21 around a pollution source 11. As shown in FIG. 2, the cross section of each columnar duct 20 has a partition plate 20a inside, one side serving as an air curtain blowout duct 20b, and the other side serving as an air curtain suction duct 20c.
The blow-off duct 20b and the suction duct 20c each have a blow-off slit 20d and a suction port 20e, which are vertical openings along the columnar duct 20. Each of the four columnar ducts 20 has a blowout slit 20.
d and the suction port 20e are arranged to face each other. The blowout duct 20b in the columnar duct 20 serves as the supply duct 23 of the air curtain blower 22, and the suction duct 20c serves as the suction duct 2 of the blower 22.
4 are connected to each other. At the center of the four columnar ducts 20 and directly above the pollution source 11, there is a contaminated air suction hood 25. This contaminated air suction hood 25 can be raised and lowered in the vertical direction by lifting means (not shown) by lifting guide rollers 26 and hanging wire ropes 27 provided on each side of the columnar duct 20. The inside of the contaminated air suction hood 25 has a suction surface 25a as shown in FIG.
has a cone shape, and a plurality of directional suction holes 25b are provided along the inner surface of the cone shape,
One suction nozzle 25c is provided at the top of the cone. A negative pressure chamber 25 is provided in the suction hood 25.
d, and the suction nozzle 25c is directly connected to the suction hole 25b through a suction pipe 25e. The upper part of the negative pressure chamber 25d is connected to an exhaust fan 17 by a flexible duct 15.
and a contaminated air exhaust device 18 consisting of a filter 16
It is connected to.

The operation of this embodiment configured as described above will be explained next.

Blowout duct 20b inside four columnar ducts 20
The air curtain flow ejected from the blowout slit 20d flows into the suction port 20e of the suction duct 20c in the columnar duct 20 facing each other. By forming a similar air curtain flow between the four columnar ducts 20, a continuous spiral cross-flow air curtain 28 is formed around the pollution source 11, and the flow from the pollution source 11 is Diffusion of contaminated air can be prevented and shielded.

Air volume adjusting dampers 23a and 24a are provided in the middle of the supply duct 23 and the suction duct 24, which are connected to the blow-off duct 20b and the suction duct 20c in each columnar duct 20, respectively, so that the cross-flow air curtain 28 is evenly distributed. It is now possible to form

The contaminated air generated from the pollution source 11 is surrounded by the spiral cross-flow air curtain 28 and the artificial coil 29 generated by the suction action of the directional suction hole 25b in the contaminated air suction hood 25,
The above-mentioned suction hood 2 becomes a twisted upward air current 30.
5, passes through the flexible duct 26, passes through the filter 27b, and is exhausted by the exhaust fan 17.

In this embodiment, the suction hood 25 is designed to be able to move up and down directly above the pollution source 11. Therefore, when the device starts operating, the suction hood 25 is brought close to the pollution source 11, and the suction hood 25 is moved up and down. By strongly exerting the negative suction pressure of the suction nozzle 25c, the generation of the artificial coil 29 is facilitated.

If the state of generation of the artificial coil 29 is weak, the undeveloped artificial coil 29 can be stabilized by repeating the above-mentioned lifting and lowering operation multiple times.

The suction air velocity of the suction nozzle 25c in the suction hood 25 is, for example, 20 to 30 m/s, so that the suction airflow of the plurality of suction holes 25b on the cone-shaped suction surface 25a is It has the effect of accelerating the swirling wind speed.

As an example, in a reactor twist pool 40 of a nuclear power plant as shown in FIG. 4, the diameter of the pool is approximately 10 m, the exit wind speed at the blowout slit 20d is 2 to 3 m/s, and the inlet wind speed is at the inlet 20e. 8～10
For m/s, good cross-flow air curtain, 28
It has been experimentally confirmed that it can be formed.

As explained above, contaminated air is artificial
and the cross-flow air curtain 28 on the outside, which completely isolates it from the outside air.
The upward airflow 30 to the suction hood 25 is also focused into a twisted thread to effectively shield and exhaust contaminated air.

Next, a modification of this embodiment will be described.

() In this embodiment, there are four columnar ducts 20, but any number may be used as long as there are at least three or more. By increasing the number of air curtains, the cross-flow air curtain 28 becomes more stable. However, if there are too many columnar ducts 20, the columnar ducts 20 may get in the way of maintenance.

() In this embodiment, a portable contaminated air diffusion prevention device is provided with flexible wheels 31 at the bottom of four columnar ducts 20 and an air curtain blower 22 at the top of a frame 12 combined with four columnar ducts 20. However, the flexible wheels 31 may be omitted and the air curtain blower 22 may be installed at a location other than the top of the frame 12 to provide a fixed contaminated air diffusion prevention device.

() In this embodiment, the flexible duct 15 connected to the suction hood 25 is used as a suction duct, but it is also possible to install the contaminated air exhaust device 18 on the suction hood 25 and use the flexible duct 15 as an exhaust duct. good.

() In this embodiment, a lifting guide roller 26 is provided on the side surface of each columnar duct 20 as a guide for lifting the suction hood 25 up and down, but as shown in FIG. A wire rope 27 may be provided in the center and supported by a pulley 41, and may be raised and lowered.

() In this embodiment, the air curtain blower 22 for supplying and suctioning pressurized air to the columnar duct 20 is used for both supplying and suctioning.
It may be installed separately into a supply-only blower and a suction-only blower. By having separate equipment, it becomes easier to adjust and distribute the wind speed between the blowout slit 20d and the suction port 20e, and a better cross-flow air curtain 28 can be formed.

〔Effect of the invention〕

According to the present invention, by arranging at least three columnar ducts each having an air curtain outlet and an inlet around a pollution source, it becomes possible to cope with an increase in the size of the pollution source. Furthermore, by making the suction hood movable up and down and by providing a plurality of directional suction holes in the suction hood, it becomes easier to induce the generation of artificial coiling. Furthermore, the rotation speed of the artificial coil is accelerated, making it possible to more effectively prevent and exhaust contaminated air.

[Brief explanation of drawings]

Fig. 1 is a side view showing the configuration of an embodiment of the present invention, Fig. 2 is a planar system diagram of Fig. 1, Fig. 3 is a sectional view of the suction hood according to the embodiment, and Fig. 4 is FIG. 5 is a side view of an application example of this embodiment, FIG. 5 is a side view of a conventional example, and FIG. 6 is a sectional view taken along line A--A in FIG. 11... Pollution source, 12... Frame, 15...
Flexible duct, 16...Filter, 17
...Exhaust fan, 18...Contaminated air exhaust device, 2
0...Columnar duct, 20b...Blowout duct, 2
0c...Suction duct, 20d...Blowout slit,
20e... Suction port, 21... Mounting surface, 22... Air curtain blower, 25... Suction hood, 2
5b... Suction hole, 27... Hanging wire rope,
28...Crossflow air curtain, 29...Artificial winding, 30...Updraft.

Claims (1)

[Claims] 1 Gather the air curtain outlet and the air curtain inlet into one column-shaped duct, and connect at least three of them so that one outlet of this column-shaped duct faces the inlet of the other column-shaped duct. The columnar ducts are arranged upright, a blower is installed separately to supply and suck pressurized air to these columnar ducts, and a contaminated air suction hood is installed in the center of the group of columnar ducts. A contaminated air suction hood can be raised and lowered in the vertical direction, and a plurality of directional suction holes are provided in the contaminated air suction hood so that the suction direction is the same as the suction port of the columnar duct. A contaminated air diffusion prevention device featuring: