GB2350295A

GB2350295A - Fire damper for a duct

Info

Publication number: GB2350295A
Application number: GB0007673A
Authority: GB
Inventors: Jouni Tuomi
Original assignee: FLAEKT Oy; ABB Flaekt Oy
Current assignee: FLAEKT Oy; Flaekt Woods Oy
Priority date: 1999-03-31
Filing date: 2000-03-29
Publication date: 2000-11-29
Anticipated expiration: 2020-03-29
Also published as: SE0001099L; FI990721A0; SE0001099D0; GB0007673D0; FI105129B; GB2350295B; SE522541C2

Abstract

The damper has a flange part for connecting the flue gas damper to air-conditioning ducts, at least one rotatable damper 2 disposed in the flange part and an actuator 4 which in case of fire is arranged to move the damper 2 from an open position to a closed position. A reinforcement plate 5 is arranged outside the flange part, substantially at the damper 2, to prevent deformations caused by temperature at the damper and near it.

Description

2350295 Flue Gas Damper The present invention relates to a flue gas

damper.

In mechanical centralized air-conditioning systems, very different areas are usually connected to each other. For the sake of fire safety, it has become necessary to isolate such areas. In case of fire, air-conditioning ducts may act as efficient distributors of flue gas, fire and heat, and this is why it has been extremely important to develop automatically operating seals for air-conditioning ducts. For this reason, current air-conditioning systems are partitioned and flue gas dampers are placed between the partitions.

However, the problem with these flue gas dampers is that they are not sufficiently tight. The rise in temperature produced by a fire causes changes in the materials of flue gas dampers, for example thermal expansion.

Consequently, the need has arisen to develop flue gas dampers which retain their tightness even when changes due to heat occur in the materials of the flue gas dampers. A particular problem is caused by the flange part being heated, since it leads to the softening and expansion of the flange part, resulting in impaired tightness between the flange part and the damper.

It would be desirable to provide a fiue'gas damper which solves the above problems.

The present invention provides a flue gas damper comprising a flange part for connecting the flue gas damper to air-conditioning ducts, at least one rotatable damper disposed in the flange part and rotatable around a shaft from an open position to a closed position, and an actuator which in case of fire is arranged to control the damper from the open position to the closed position, wherein the damper in its closed position is adapted to block the passage in the flange part from one side of the damper to its other side and vice versa, and wherein a reinforcement plate is arranged outside the flange part, substantially at the damper, to prevent deformations caused by temperature at the damper and near it.

The preferred embodiments of the flue gas damper of the invention are disclosed in the dependent claims.

The invention is based on the reinforcement plate supporting the flange part at the damper so that the shape and dimensions of the flange part 2 at the damper cannot change due to temperature. As a result, the flue gas damper of the invention remains tight, since the flange part cannot change its shape or dimensions so that hot gases could flow between the damper in its closed position and the inner surface of the flange part.

In the following, the invention will be described in greater detail in connection with preferred embodiments with reference to the accompanying drawings, in which Figure 1 is a side view of a flue gas damper of the invention, Figure 2,shows a flue gas damper of the invention, seen from one end, Figure 3 shows a reinforcement ring seen from one of its front sur faces, and Figure 4 shows a reinforcement ring.

Figures 1 and 2 show a flue gas damper comprising a flange part I for connecting the flue gas damper to air-conditioning ducts (not shown).

In the figures, the flange part 1 is a tubular piece. The flange part 1 is preferably made from steel.

The flue gas damper of the invention comprises at least one ro tatable damper 2 disposed in the flange part 1 and rotatable around a shaft 3 from an open position to a closed position. The flue gas damper according to the figures comprises one rotatable damper 2.

The damper 2 preferably has a stratified structure (not shown), be ing composed of a plurality of different heat and fire-resistant plates or the like. The damper 2 and the inner surface of the flange part 1 are preferably painted with a fire-retardant paint. Between the damper 2 and the inner sur face of the flange part 1 is preferably a sea[ (not shown) which in the closed position of the damper 2 is so disposed that it blocks the flow path between the damper 2 and the inner surface of the flange part 1.

The figures show a flue gas damper comprising a flange part 1 which has a substantially circular cross-section, and a substantially circular damper 2, but these parts may alternatively have other shapes. For example the flange part 1 may have a rectangular cross-section, and the damper 2 may have a rectangular shape. What is. essential is that the dimensions and 3 shapes of the flange part 1 and the damper 2 with respect to one other are compatible so that the damper 2 is capable of closing off the passage in the flange part 1 from one side of the damper 2 to its other side and vice versa.

The flue gas damper of the invention also comprises an actuator 4 which in a fire is arranged to rotate the damper 2 from an open position to a closed position wherein the damper 2 in its closed position is adapted to block the passage in the flange part 1 from one side of the damper 2 to its other side and vice versa. If there are more than one damper 2, each damper 2 may have an actuator 4 or, alternatively, the same actuator 4 can be used to con trol all dampers 2.

In the flue gas damper according to the figures, the actuator 4 is connected to a shaft 3 and the shaft 3 is fastened to the damper 2. In other words, the damper 2 is controlled by having the actuator 4 rotate the shaft 3, making the thereto fastened damper 2 turn from an open position to a closed position, or vice versa. Alternatively, the actuator 4 may control the damper 2 in some other manner.

Outside the flange part 1 of the flue gas damper, substantially at the damper 2, is arranged a reinforcement plate 5 to prevent deformations caused by temperature in the flange part 1 at the damper 2 and near it.

The figures shows the reinforcement plate 5 as a circular ring hav ing an inner diameter which substantially corresponds to the outer diameter of the flange part 1 at the damper 2.

In the figures, the reinforcement plate 5 is fastened substantially on the same level as the damper 2 to make the flange part 1 be pressed between the reinforcement plate and the damper 2 when the damper 2 and the rein forcement plate 5 expand under the influence of heat.

The reinforcement plate 5 according to the figures comprises means 6 for fastening it to a support element 7 at the actuator. In the figure, these means 6 are composed of two parts which are perpendicular to the re inforcement plate 5 and fastened to the support element 7 of the actuator.

Fastening the reinforcement plate 5 to the support element 7 of the actuator provides a stable structure.

In the figures, the reinforcement plate 5 is fastened to the flange part 1 by means of fastening blocks 8 having an L-shaped cross-section. In the figures, these fastening blocks 8 are welded to the flange part 1 and the reinforcement plate 5. Alternatively, these fastening blocks 8 can be fastened 4 by mechanical fastening means (not shown) either to the flange part 1 or the reinforcement plate 5 or to both. The fastening blocks 8 may also be seam lessly fastened to the reinforcement plate 5, i.e. they are fixed parts of the re inforcement plate 5.

The flue gas damper of the invention preferably comprises at least one insulating plate (not shown) or the like, fastened to the reinforcement plate 5 in such a manner that the insulating plate or the like and the rein forcement Plate 5 together with the damper 2 in the closed position constitute a structure which is at least partly adapted to block the thermal bridge in an air-conditioning system.

The insulating plate and the reinforcement plate 5 together with the damper 2 in the closed position preferably constitute a substantially inte grated, plane structure. The structure formed by the insulating plate and the reinforcement plate 5 is preferably substantially on the same level as the damper 2 when in the closed position.

It is obvious to a person skilled in the art that as technology ad vances, the basic idea of the invention can be implemented in a variety of ways. Consequently, the invention and its embodiments are not restricted to the above examples but may vary within the scope of the claims.

Claims

1. A flue gas damper comprising a flange part for connecting the flue gas damper to air-conditioning ducts, at least one rotatable damper disposed in the flange part and rotatable around a shaft from an open position to a closed position, and an actuator which in case of fire is arranged to control the damper from the open position to the closed position, wherein the damper in its closed position is adapted to block the passage in the flange part from one side of the damper to its other side and vice versa, and wherein a reinforcement plate is arranged outside the flange part, substantially at the damper, to prevent deformations caused by temperature at the damper and near it.

2. A flue gas damper as claimed in claim 1, wherein the reinforcement plate and the damper are fastened substantially on the same level.

3. A flue gas damper as claimed in claim 1 or 2, wherein the reinforcement plate is a circular ring having an inner diameter which substantially corresponds to the outer diameter of the flange part at the damper.

4. A flue gas damper as claimed in claim 1, 2 or 3, wherein the reinforcement plate comprises means for fastening it to a support element at the actuator.

5. A flue gas damper as claimed in any.preceding claim, wherein the reinforcement plate is fastened to the flange part by means of fastening blocks having an L-shaped cross-section.

6. A flue gas damper as claimed in any preceding claim, wherein it comprises at least one insulating plate or the like, fastened to the reinforcement plate, and that the insulating plate or the like and the reinforcement plate together with the damper in the closed position constitute a structure which is at least partly adapted to block the thermal bridge in an air- conditioning system.

7. A flue gas damper as claimed in claim 6, wherein the insulating plate or the like and the reinforcement plate together with the dampner in the closed position constitute a substantially integrated, plane structure.

8. A flue gas damper as claimed in claim 6, wherein the structure formed by the insulating plate or the like and the reinforcement plate is substantially on the same level as the damper when in the closed position.

9. A flue gas damper as substantially hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings.