JP2006329444A - Damper device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize airflow at an upstream side of flat blades with respect to a damper device for preventing backflow, used in a ventilation air conditioning system of nuclear facilities. <P>SOLUTION: This damper device 40 for preventing backflow has a damper main body portion 42. The damper main body portion 42 comprises the plurality of flat blades 28 arranged in parallel with each other along a cross-section of a ventilation duct 16. The flat blades 28 are independently rotatable, and straightening portions 44 are formed at an upstream side of the flat blades 28. The straightening portions 44 have straightening plates 50 respectively mounted between the flat blades 28. Each straightening plate 50 is mounted along the airflow 46, and movable along the cross-section of the ventilation duct 16, and the inside of the ventilation duct 16 is sectioned into a plurality of split flow channels 54. Each split flow channel 54 is provided with a flow adjusting mechanism 52. The flow adjusting mechanism 52 is composed of a pair of relatively movable porous plates, and the quantity of airflow 46 flowing in the split flow channels 54 can be adjusted by changing an aperture ratio. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a damper device provided in a flow path of airflow, and more particularly to a damper device for preventing a backflow used in a ventilation air conditioning system of a nuclear facility.

  A nuclear facility such as a nuclear power plant has a ventilation air-conditioning system in order to maintain a constant environment in the building. In addition, nuclear facilities maintain negative pressure in the building to prevent leakage of radioactive materials to the outside, and install a filter in the ventilation path of the ventilation air conditioning system to capture dust discharged from the building. So that it is not released to the outside. The exhaust system of the ventilation air conditioning system is, for example, as shown in FIG.

  That is, as shown in FIG. 3, the exhaust system 10 is provided with an exhaust duct 16 that forms a ventilation path in the ceiling space 14 of the building 12. Discharge side ducts 19 of a plurality of exhaust fans (blowers) 18 installed in the ceiling space 14 are connected to the exhaust duct 16 in parallel. These exhaust fans 18 suck the air in the room 20 and discharge it to the exhaust duct 16 as indicated by arrows 22. The discharge-side duct 19 of the exhaust fan 18 constituting the ventilation path is provided with a backflow prevention damper device 24, and when the operation of the exhaust fan 18 is stopped, air and dust in the exhaust duct 16 are removed. Backflow into the room 20 through the exhaust fan 18 is prevented.

  The backflow preventing damper device 24 is configured as shown in FIG. 4, for example, and has a frame-like casing 26 attached to the discharge side pipe line 19 of the exhaust fan 18. A plurality of flat blades 28 are arranged in parallel and attached to a casing 26 that forms a flow path cross section of the ventilation path. Each flat blade 28 is independently rotatable, and is attached with a counterweight 30 so as to be easily rotated. That is, as shown in FIG. 5, the flat blade 28 has a fitting recess 32 having a semicircular cross section formed on the upper end side, and is joined to a shaft 34 fitted to the fitting recess 32. is there. The shaft 34 is rotatably supported by the casing 26, and a counterweight 30 is attached to one end thereof. The flat blades 28 are rotated by the air flow discharged by the exhaust fan 18 to open the discharge side pipe line 19. Such a backflow preventing damper device 24 may be installed in the exhaust duct 16.

However, the flat blade 28 of the damper device 24 for backflow prevention may show an unstable behavior depending on the state of the air flow in the exhaust duct 16, and the flat blade 28 is always oscillated and provided in the exhaust duct 16. The filter (not shown) is vibrated to damage the filter, or the joint between the flat blade 28 and the shaft 34 is fatigued. Therefore, a perforated plate capable of adjusting the aperture ratio is arranged upstream of the flat blade 28 to rectify the air flow, and to a damper device that suppresses the swing of the flat blade, or to the tip bent portion 36 of the flat blade 28. A damper device provided with a baffle plate so as not to be exposed to airflow has been proposed (Patent Documents 1 and 2).
JP 2000-18697 A JP 2000-74475 A

  In a building in a nuclear facility or the like, the installation space for the exhaust fan 18 and the exhaust duct 16 is reduced. For this reason, even if the length of the exhaust duct 16 in which the backflow preventing damper device 24 is installed cannot be secured sufficiently, and the structure as in Patent Document 1 or Patent Document 2 is adopted, the flat blade 28 is used. There is concern that the airflow in the vicinity becomes unstable. When the air flow becomes unstable, a phenomenon occurs in which the opening / closing behavior between the flat blades 28 is different, and in the flat blade 28 having a large number of opening / closing operations, an excessive load stress is generated at the joint portion with the shaft 34, and the short-term behavior is reduced. There is a risk of fatigue failure of the flat blade 28 between the two. In particular, the airflow flowing near the wall surface of the ventilation path tends to be unstable.

  The present invention has been made to remedy the drawbacks of the prior art and aims to stabilize the airflow upstream of the flat blades.

  In order to achieve the above object, a plurality of damper devices according to the present invention are provided in parallel along a cross section of the air flow path, each of which is independently rotatable, Arranged along the flow of the airflow on the upstream side, provided movably along the cross section of the flow path, rectified the airflow and partitioned by the flow rectification plate and dividing the flow path A flow rate adjusting mechanism that is provided corresponding to a plurality of divided flow paths and adjusts the amount of the airflow flowing through the corresponding divided flow paths.

  Further, a plurality of damper devices according to the present invention are provided in parallel along a cross section of the air flow, and each of the damper blades is independently rotatable, and the outer side of the flat blades on the upstream side. It is arranged along the flow of the airflow corresponding to the flat blades, and is provided movably along the cross section of the flow path to rectify the airflow and form a divided flow path that opens and closes the outer flat blades And a flow inlet adjusting member that is rotatably provided at a tip of the flow straightening plate and changes an inlet area of the divided flow path. The divided flow path formed by the rectifying plate and the flow path wall may be provided with a flow rate adjusting mechanism for adjusting the amount of airflow flowing through the divided flow path.

  The damper device according to the present invention as described above rectifies the flow of the air flow by providing a plurality of rectifying plates along the flow of the air flow. Further, a flow rate adjusting mechanism is provided in the divided flow path formed by the rectifying plate to adjust the amount of airflow flowing through the divided flow path. For this reason, it is possible to easily stabilize the airflow in each divided flow path, to stabilize the behavior of the flat blades on the downstream side of the divided flow paths, and to prevent unnecessary loads from acting on the flat blades. Can do. Therefore, fatigue failure of the flat blade can be prevented, and the reliability of the damper device can be improved. Moreover, since the flow path (ventilation path) through which the airflow flows is divided into a plurality of divided flow paths by the rectifying plate, the area of the cross section of the flow path that stabilizes the airflow is divided into small areas, so Can be easily stabilized. Furthermore, since the rectifying plate is movable along the cross section of the flow path, the airflow state between the divided flow paths can be made the same, and an excessive load stress is applied to some flat blades. It can be prevented from acting.

  Further, the damper device of the present invention rectifies the airflow near the wall surface of the flow path, which is likely to be unstable, by the current plate, and the flow path wall surface and the current plate by the inlet adjustment member provided at the tip of the current plate. Thus, the area of the inlet of the divided flow path formed is changed to adjust the amount of airflow flowing through the divided flow path. For this reason, it can prevent that the state of the air current near the wall surface of the flow path becomes unstable, and the behavior of the flat blade can be stabilized. By providing a flow rate adjusting mechanism in the divided flow path, the amount of airflow can be adjusted together with the inlet adjustment member, and the airflow flowing through the divided flow can be easily stabilized.

  Preferred embodiments of a damper device according to the present invention will be described in detail with reference to the accompanying drawings. In addition, about the part corresponding to the part demonstrated in the said background art, the same code | symbol is attached | subjected and the description is abbreviate | omitted. Moreover, in the following embodiment, the case where it installs in the exhaust duct which is a ventilation path is demonstrated as an example.

  FIG. 1 is an explanatory view in which a part of the damper device according to the first embodiment of the present invention is shown in cross section. In FIG. 1, the backflow preventing damper device 40 is composed of a damper main body portion 42 and a rectifying portion 44. The damper main body 42 includes a casing 26 that is fixed to the inner wall of the exhaust duct 16. A plurality of flat blades 28 are rotatably attached to the casing 26 via a shaft 34. These flat blades 28 rotate independently of each other. When the airflow 46 does not flow through the exhaust duct 28, the flat blade 28 has its tip directed downward in FIG. 1 to close the exhaust duct 16 due to its own weight, and dust and the like in the exhaust duct 16 flow backward into the room. To prevent. Each flat blade 28 rotates in the counterclockwise direction of FIG. 1 by the wind pressure when the air flow 46 flows as shown by an arrow, and opens the exhaust duct 16. The reference numeral 48 shown in FIG. 1 is an airflow guide plate that prevents the airflow 46 from hitting the bent end portion 36 of the flat blade 28 when the flat blade 28 opens the exhaust duct 16.

The rectifying unit 44 is provided on the upstream side of the damper main body 42, that is, the flat blade 28, and includes a plurality of rectifying plates 50 (50a, 50b, ... 50m) and a plurality of flow rate adjusting mechanisms 52 (52a, 52a, 52b,... 52n). The rectifying plate 50 is located between the flat blades 28, and the base end portion is attached to the casing 26 of the damper main body 42. And each baffle plate 50 is arrange | positioned along the flow of the airflow 46, and while rectifying the airflow 46, the inside of the exhaust duct 16 is divided into the some division | segmentation flow path 54 (54a, 54b, ... 54n). ing. Each rectifying plate 50 is movable in the vertical direction along the surface formed by the casing 26, that is, the flow passage cross section of the exhaust duct 16, and can be fixed at an arbitrary position in the vertical direction. Therefore, each divided flow channel 54 can arbitrarily change the vertical dimension L (L ₁ , L ₂ ,... L _n ).

  The flow rate adjusting mechanism 52 is provided corresponding to each divided flow path 54, and is disposed on the front end side of the rectifying plate 50. In the case of the embodiment, the flow rate adjusting mechanism 52 is composed of a pair of perforated plates that can move relative to each other. The amount of the air flow 46 flowing through the path 54 can be adjusted.

  The backflow preventing damper device 40 thus configured rectifies the airflow 46 so that the flow of the airflow 46 flows smoothly by the rectifying plate 50. Further, the air flow flowing through each divided flow channel 54 is adjusted by moving the pair of perforated plates constituting the flow rate adjusting mechanism 52 relative to each other to change the aperture ratio and adjusting the amount of the air flow 46 flowing through the divided flow channel 54. 46 can be stabilized. Thereby, the behavior of each flat blade 28 is stabilized, it is possible to prevent an excessive load from acting on the flat blade 28, fatigue damage of the flat blade 28 can be prevented, and reliability can be improved. In the embodiment, since the inside of the exhaust duct 16 is divided into a plurality of divided flow paths 54 by the rectifying plate 50, the flow path cross section for stabilizing the air flow 46 is divided into small parts, and the air flow in the divided flow paths 54 46 can be easily stabilized. Moreover, since the rectifying plate 50 is movable along the cross section of the flow path, the cross-sectional area of each divided flow path 54 can be adjusted to make the state of the air flow 46 in the divided flow path pipe the same. It is possible to avoid an excessive load from acting on some of the flat blades 28.

  FIG. 2 is an explanatory view showing a part of the second embodiment in cross section. The backflow preventing damper device 60 according to this embodiment includes a flat blade 28 positioned outside the plurality of flat blades 28, that is, the uppermost flat blade (not shown) in FIG. 2 and the lowermost flat plate. A rectifying unit 62 (62a, 62b) is provided corresponding to the blade 28n. Each rectifying unit 62 includes a rectifying plate 50 (50a, 50b) and a flow rate adjusting mechanism 52 (52a, 52b). Each rectifying plate 50 is configured to be movable along the cross section of the flow path, as in the above embodiment.

  The flow rate adjusting mechanism 52 is configured by a pair of perforated plates that can move relative to each other and change the aperture ratio, as in the above embodiment. One flow rate adjusting mechanism 52a is disposed in the divided flow path 54a formed by the wall surface of the exhaust duct 16 and the rectifying plate 50a, and can adjust the amount of the air flow 46 flowing through the divided flow path 54a. ing. The other flow rate adjusting mechanism 52b is disposed in the divided flow path 54b formed by the wall surface of the exhaust duct 16 and the rectifying plate 50b, and adjusts the amount of the air flow 46 flowing through the divided flow path 54b. In this embodiment, the flow rate adjusting mechanism is not provided in the divided flow path 54c formed in the central portion in the vertical direction of the exhaust duct 16 by the rectifying plate 50a and the rectifying plate 50b. This is because the air flow 46 c flowing through the central portion of the exhaust duct 16 is more stable than the air flows 46 a and 46 b flowing near the wall surface of the exhaust duct 16.

  An inlet adjusting plate (inlet adjusting member) 64 (64a, 64b) is rotatably attached to the tip of each rectifying plate 50a, 50b. The inlet adjustment plates 64a and 64b change the inlet area of the divided flow paths 54a and 54b by changing the inclination angle θ with respect to the rectifying plate 50, and change the amount of the airflow 46 flowing into the divided flow paths 54a and 54b. It can be done.

  The backflow preventing damper device 60 according to the second embodiment rectifies the airflow near the wall surface of the exhaust duct 16 where the airflow 46 is likely to be unstable, and forms the divided flow paths 54a and 54b adjacent to the wall surface. At the same time, since the inlet adjustment plate 64 is provided so that the amount of the airflow 46 flowing into the divided flow paths 54a and 54b can be adjusted, the airflow near the wall surface of the exhaust duct 16 can be stabilized. In addition, since the flow rate adjusting mechanism 52 is provided in the divided flow paths 54a and 54b so that the amount of the air flow 46 flowing through the divided flow paths 54a and 54b can be adjusted, the air flow can be stabilized more easily. Moreover, since the flow rate adjusting mechanism is not provided in the divided flow path 54c at the center of the exhaust duct 16 where the airflow 46 is relatively stable, the structure can be simplified and the cost can be reduced.

  In addition, the said embodiment is 1 aspect of this invention, Comprising: It is not limited to these. For example, in the backflow preventing damper device 40 of the first embodiment, the inlet adjustment plate 64 shown in the second embodiment may be rotatably provided at the tip of the rectifying plate 50. In the backflow preventing damper device 60 according to the second embodiment, the flow rate adjusting mechanism 52 is provided in the divided flow paths 54a and 54b. However, the opening ratio cannot be changed in place of the flow rate adjusting mechanism 52. A perforated plate may be arranged, or the flow rate adjusting mechanism 52 and the perforated plate may be arranged, and the amount of airflow flowing into the divided flow paths 54a and 54b may be adjusted only by the inflow port adjusting plate 64. .

It is explanatory drawing which made a cross section a part of damper device for backflow prevention concerning a 1st embodiment. It is explanatory drawing which made a cross section the part of the damper apparatus for backflow prevention which concerns on 2nd Embodiment. It is explanatory drawing which shows an example of the exhaust system of a nuclear facility. It is explanatory drawing of the damper device for the conventional backflow prevention. It is a perspective view which shows the detail of a flat blade.

Explanation of symbols

16 ......... Ventilation path (exhaust duct), 18 ......... Exhaust fan, 28 ......... Flat blade, 30 ......... Counterweight, 40, 60 ...... Damper device for backflow prevention, 42 ......... Damper Main part 44 ......... Rectifying part 46 ......... Airflow 50a, 50b, 50m ......... Rectifying plate 52a, 52b, 52n ......... Flow rate adjusting mechanism 54a, 54b, 54n ......... Division flow , 62a, 62b... Rectifier, 64a, 64b... Inlet adjustment member (inlet adjustment plate).

Claims (3)

A plurality of blades arranged in parallel along the cross section of the air flow path, each of which is independently rotatable,
A plurality of rectifying plates that are arranged along the flow of the airflow upstream of the flat blades and are movably provided along the flow path cross section to rectify the airflow and divide the flow path; A flow rate adjusting mechanism which is provided corresponding to a plurality of divided flow paths partitioned by a plate and adjusts the amount of the airflow flowing through the corresponding divided flow paths;
A damper device comprising: A plurality of blades arranged in parallel along the cross section of the air flow path, each of which is independently rotatable,
It is arranged along the flow of the airflow corresponding to the outer flat blade on the upstream side of the flat blade, and is provided movably along the cross section of the flow path to rectify the airflow and A rectifying plate that forms a divided flow path in which the flat blades open and close;
An inlet adjustment member that is rotatably provided at the tip of the current plate, and that changes the inlet area of the divided flow path;
A damper device comprising: The damper device according to claim 2, wherein
A damper device comprising a flow rate adjusting mechanism that is provided in the divided flow path formed by the rectifying plate and the flow path wall and adjusts the amount of the airflow flowing through the divided flow path.

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