GB2561581A

GB2561581A - Damper

Info

Publication number: GB2561581A
Application number: GB1706186.2A
Authority: GB
Inventors: Turley James; Schmidt Emil; Backham Mike
Original assignee: BSB ENGINEERING SERVICES Ltd
Current assignee: BSB ENGINEERING SERVICES Ltd
Priority date: 2017-04-19
Filing date: 2017-04-19
Publication date: 2018-10-24
Also published as: GB201706186D0

Abstract

The invention provides a damper having a pivotable damper blade (5, figure 1) within a cylindrical outer housing (1, figure 1), and a mounting unit (3, figure 1) around the outer housing. There are at least two rotatable mounting brackets 10 comprising a central area and a surrounding area of a sheet material, which are rotatable between a first position in which the central area is coplanar with the surrounding area and a second position in which the central area projects perpendicularly to the surrounding area. This enables the damper to be configured to different mounting solutions. The mounting brackets may be rotatable by a plastically deforming hinge 14. An edge return portion (30, figure 3) of the mounting bracket may be provided to limit how far the central area can be bent. The damper blade may be movable between open and closed positions and may further be biased towards the closed position.

Description

(54) Title of the Invention: Damper

Abstract Title: Mounting arrangement for fire damper (57) The invention provides a damper having a pivotable damper blade (5, figure 1) within a cylindrical outer housing (1, figure 1), and a mounting unit (3, figure 1) around the outer housing. There are at least two rotatable mounting brackets 10 comprising a central area and a surrounding area of a sheet material, which are rotatable between a first position in which the central area is coplanar with the surrounding area and a second position in which the central area projects perpendicularly to the surrounding area. This enables the damper to be configured to different mounting solutions. The mounting brackets may be rotatable by a plastically deforming hinge 14. An edge return portion (30, figure 3) of the mounting bracket may be provided to limit how far the central area can be bent. The damper blade may be movable between open and closed positions and may further be biased towards the closed position.

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FIG. 1

FIG. 2

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FIG. 3

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FIG. 4

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FIG. 5

FIG. 6

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FIG. 7

DAMPER

Field of the invention

This invention relates to a damper for providing a controllable fluid passageway between volumes. It may for example relate to fire dampers.

Background of the invention

Fire dampers are used in air-flow ducting, such as is used in heating ventilation and air-conditioning (HVAC) systems, to prevent the spread of fire in a building along the ducting. There is a wide variety of different types of fire damper available.

One example of fire damper which is commonly used in HVAC systems comprises a tubular casing for installation in a length of ducting and a circular blade within the body. The casing and blade are typically made of steel, is although the blade may instead be formed of a composite material. The damper blade pivots between open and closed positions on an axle supported centrally within the damper casing. The circular blade design has the advantage that the manufacture is simple, for example with a single movable blade which pivots on an axle and a cylindrical outer casing that can be made accurately with low cost.

A louvre design is more complicated to manufacture with multiple blades and a linkage system, but it can be scaled to larger dimensions.

There are also designs for rectangular ducting, which operate in the same way.

Such dampers are typically installed in a duct where it passes through a wall or floor. In the event of a fire, the heat causes the damper blade to close, thereby maintaining fire integrity where the duct passes through the wall or floor.

The damper may be installed to an existing wall. In this case, a hole is drilled through the wall, and the damper has a mounting flange which sits around the hole and presses flush against the wall. The flange is then fixed to the wall through openings in the flange.

The damper may alternatively be installed during the process of building to a wall. In this case, the damper has mounting brackets to enable it to be suspended at a desired location in space, using rods passing up from the floor or down from the ceiling. The wall is then built around the fire damper.

Generally, this means there are two designs of fire damper, one for retrofitting and one for new installation. A third type of design is a conventional volume control damper fitted mid-span within a wall.

It would be desirable to enable a single design to be used, so that the component count could be reduced, further economies of scale could be obtained, and the problem of having the wrong design on site is eliminated.

Summary of the invention

According to the invention, there is provided a damper as claimed in claim 1.

is In accordance with the invention, there is provided a damper, comprising:

a pivotable damper blade within a tubular outer housing; and a mounting unit around the outer housing, comprising:

at least two rotatable mounting brackets comprising a central area and a surrounding area of a sheet material, which are rotatable between a first position in which the central area is coplanar with the surrounding area and a second positon in which the central area projects perpendicularly to the surrounding area.

The mounting brackets may be kept in a coplanar configuration or they may be bent out to provide supports for suspending the damper from above or standing it on supports below. In this way, a single design is able to be used for both retrofit and new installation applications. This saves on manufacturing costs in both materials and labour as well as offering the flexibility of two installation methods combined into one design.

Another benefit of the rotatable mounting bracket is that it is better for damper transportation, as it does not protrude therefore is less likely to get damaged or cause any damage.

The tubular outer housing may be circular cylindrical or rectangular cylindrical.

The mounting bracket may be formed by a U-shaped cut track in the sheet material. Thus, the mounting bracket does not require any additional material at all, and is defined by a cut-out (such as a pressed shape).

The mounting brackets may be rotatable by plastically deforming a hinge line. This plastic deformation, for example of a metal flange, means the mounting brackets retain their position, to ease the installation.

The hinge line may include a row of slots to assist the mounting bracket to fold in the correct position in a neat and tidy manner.

The mounting brackets may include an edge return portion which limits how far the central area can be bent out and provides additional strength.

In one set of examples, the mounting unit comprises a mounting flange and the sheet material comprises the mounting flange. The mounting bracket is thus comprises a portion of the flange, i.e. the sheet material of the mounting bracket is the flange. This means it requires no additional components or material to the existing flange.

This relates for example to a fire damper design, in which a mounting flange extends around the damper housing.

The mounting flange for example comprises mounting holes passing through the flange to enable flush surface mounting of the flange, and wherein the flange forms the surrounding area of the mounting brackets.

The mounting holes through the flange enable surface mounting, and the mounting brackets may then be kept in a coplanar configuration so that they do not detract from the surface mounting.

The mounting bracket is for example designed so that when rotated out, the position of a mounting hole in the bracket aligns with existing support channel designs to allow any combination of drop-rod and channel to be utilised.

The mounting holes (for surface mounting) are for example formed in the mounting brackets. Thus, the same set of mounting holes are used for surface or suspension mounting. This limits the number of holes needed.

However, the mounting holes may be formed in the flange away from the mounting brackets, so that there are surface mounting holes not part of the mounting brackets as well as holes forming part of the mounting brackets.

There may be four mounting brackets around the flange. Thus, there 5 may be two at the top for suspension mounting and two at the bottom for mounting from below.

The flange may be square or rectangular, with one mounting bracket at each corner of the flange.

In one example, the damper blade is movable between open and closed 10 positions, and the fire damper further comprises:

a biasing member, which urges the damper blade into the closed position; and a retention mechanism for retaining the damper blade in the open position, the retention mechanism being adapted to respond to exposure to is temperatures above a threshold temperature by releasing the damper blade so that it is urged into the closed position by the biasing member.

This defines a mechanical spring operated system.

In another arrangement, the damper blade is again movable between open and closed positions, and the fire damper further comprises:

a motor arrangement for driving the damper blade between the open and closed positions; and a control mechanism adapted to respond to exposure to temperatures above a threshold temperature thereby to control the motor arrangement to drive the damper blade to the closed position.

This defines a motor driven arrangement.

A circular housing used with the damper can have a nominal outer diameter greater than 50mm and less than 2000mm, typically greater than 100mm and less than 750mm.

Brief description of the drawings

Examples of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 shows a sectional view of a known circular fire damper;

Figure 2 shows a modified mounting flange in accordance with the invention;

Figure 3 shows a modification to the mounting bracket to provide edge return portions;

Figure 4 shows various mounting options;

Figure 5 shows a fire damper with the mounting brackets of the io mounting flange in one rotational position;

Figure 6 shows the fire damper with the mounting brackets of the mounting flange in the other rotational position; and

Figure 7 shows a volume damper.

is Detailed description

The invention provides a damper having a pivotable damper blade within a cylindrical outer housing, and a mounting unit around the outer housing. There are at least two rotatable mounting brackets comprising a central area and a surrounding area of a sheet material, which are rotatable between a first position in which the central area is coplanar with the surrounding area and a second positon in which the central area projects perpendicularly to the surrounding area. This enables the damper to be configured to different mounting solutions.

Figure 1 shows a sectional view of a known circular fire damper.

The fire damper has a damper casing 1 in the form of a steel cylinder open at each end. Swages 2a and 2b are formed in the casing 1 close to each end to strengthen the casing 1, help to maintain its round shape, and to act as a stop when fitting connecting ductwork. In the example shown, a metal flange 3 is fixed to the casing 1 to enable the casing 1 to be fixed to a part of a building’s structure, for example the wall 4 shown in Figure 1.

A damper blade 5 is shown in Figure 1 in the closed position (i.e. the position that presents maximum impedance to air-flow through the casing 1).

The blade 5 rotates between the open position (i.e. the position that presents minimum impedance to air-flow through the casing 1) and the closed position on a shaft 6 to which the blade 5 is fastened. The shaft 6 is rotatably mounted to the casing 1.

The blade 5 is urged into the closed position by a torsion spring (not shown) wound around the shaft 6. In normal operating conditions, a retaining mechanism (not shown) holds the blade 5 in the open position against the torque produced by the torsion spring. However, during a fire, the heat causes a fusible member in the retaining mechanism to melt, which releases the blade io 5, allowing the torsion spring to cause it to close.

In one version, the shaft 6 terminates in a ninety degree bend, thereby forming a handle for manual operation of the damper blade, as may be required for example during testing and servicing. In a variant, the handle is not present, and the shaft 6 instead extends to couple with a motorised is (electric or pneumatic) actuator. In this case, the torsion spring is omitted, as the required motion is provided by the motor. The motorised actuator drives the blade 5 to the open position when a thermal sensor probe inserted through a hole in the casing 1 indicates that ambient temperature is normal. If the probe detects an elevated temperature, power (or air supply) to the motor is cut and the actuator causes the blade 5 to move to the closed position.

Fire dampers such as shown in Figure 1 are required to conform to various product standards, depending on the country concerned, such as EN15650 for European dampers. Part of this typically includes a fire test using the intended installation.

The most popular installations on the market currently are either an “Angle Frame” design (i.e. using the flange 3 of Figure 1) or a “Cleated” design (i.e. using mounting brackets attached to the housing).

There is also a third option which is a combination of the two. This third option would normally be achieved by welding a pair of cleats onto the outside face of the flange in the top corners. This is normally undertaken by the manufacturer in order to comply to rules and standards. An obvious cost associated with this combined version is the manufacture of the cleats (typically a pair of fabricated 50mm x 50mm x 50mm L-shaped brackets) plus the fixing of these to the flange, typically by welding, cleaning and spray painting.

There are typically two or three subcontractors associated with building the wall, installing the dampers and ductwork, and fire stopping. It is essential that these contractors understand the install method required for each specific site, jointly coordinating the specification and their services. Often, fire dampers arrive on site with the incorrectly specified installation method attached to the damper for one reason or another, resulting in problems and io delays.

Project management of the walls and ducts/dampers dictates which type of installation method is required, which is one of two processes.

If the duct and dampers are to be installed first, a header track is typically mounted under the floor slab and drop rodding is provided, in the form is of metal threaded studding, washers and nuts, to attach to the damper cleats to support the damper. Later the wall is built around the damper.

If the wall is built first, an opening is made for the damper. The damper is then fixed to the surface of the wall by the flange.

Figure 2 shows a design of the flange to enable both fixing methods.

The flange 3 comprises at least two rotatable mounting brackets 10, which are rotatable between a first position in which they are coplanar with the flange (as shown in Figure 2) and a second positon in which they project perpendicularly to the flange.

In the example shown, a U-shaped (i.e. horse shoe shaped) slot 12 is 25 formed on the flange 3. This forms a substantially square cleat which can be bent out on site if required to give instant cleats should they be required. Usually, installations require top cleats only to suspend the damper. Thus a basic design may have just two mounting brackets, but Figure 2 shows two top and two bottom mounting brackets. By providing corner cleats at all four corners in this way, a superior damper fixing within the wall is enabled. This allows either top, top/bottom, or bottom fixing. The size of the openings within the flange are such that a popular fixing channel (typically 40mm square) can be passed through to enable the damper to be supported by this channel, that runs parallel with the damper axis. This is an alternative means of fixing to the drop rod method described above.

The material which forms the mounting bracket is already contained within the existing flange 3 and thus comprises a portion of the flange.

When bending the mounting bracket out, they bend along a hinge line

14. The hinge line may have a set of holes or slots so that bending is made easier. The mounting brackets may have optional reinforcing angles formed along the two of the side edges, that add stiffness to the brackets, act as io mechanical stops significantly strengthening the hinge of the bracket and give an automatic setting of the bent bracket position. This prevents bending of the bracket beyond 90 degrees. The angles are thus in the form of an edge return portion which limits how far the central area can be bent out and provides additional strength.

is Figure 3 shows the mounting brackets 10 in the bent out position, and it shows the reinforcing angles 30. It shows that the reinforcing angles 30 are also formed as part of the sheet of the flange. Thus, the bracket is bent out of the plane of the flange, then the reinforcing angles 30 are bent inwardly.

The mounting brackets have mounting holes 16, and these may be used for both type of connections. However, there may be additional mounting holes away from the mounting brackets in the flange for the surface mounting.

The flange is shown as square but it may be rectangular or any other shape.'

Figure 4 shows various ways of using the mounting brackets to provide mounting of a damper.

Figure 4A shows the use of two fixing channels 40 (40mm square) which are passed through the openings formed by the opened mounting brackets so the damper is supported by the two channels, that run parallel with the damper axis.

Figure 4B shows the use of two fixing channels 42 (40mm square) which are passed across the damper, so that the opened mounting brackets rest on the channels run perpendicular with the damper axis.

Figure 4C shows drop rods 44 which are bolted to the top two opened mounting brackets.

Figure 4D shows drop rods 46 which are bolted to the all four opened mounting brackets.

Figure 5 shows a perspective view with the mounting brackets flat for surface mounting and Figure 6 shows a perspective view with the mounting brackets bent out for suspension mounting.

The dampers may also be designed without the fixing flange, as shown in Figure 7. These typically comprise volume control dampers. Instead of a io flat mounting flange, there is a casing which itself has a rectangular or square cylinder shape. In this case, the fold out mounting brackets 70 may be attached to the outside face of the damper casing. This can either be done by the manufacturer at assembly, or the flat brackets 70 may be sold as a standalone product for installers to purchase and fit themselves. These flat brackets is can be left in flat coplanar orientation or bent out for use if required.

Most of the same features and benefits are obtained as for the bracket formed within the flange, although of course some extra material is used.

The invention may thus be applied to different fire dampers or volume control dampers, with square, rectangular or circular outer profiles. A volume control damper for example may have a multi-leaf opposed damper blade. Folding concertina blade packs are also known and may be used.

Various modifications will be apparent to those skilled in the art.

Claims

1. A damper, comprising:

a pivotable damper blade within a tubular outer housing; and

5 a mounting unit around the outer housing, the mounting unit comprising:

at least two rotatable mounting brackets comprising a central area and a surrounding area of a sheet material, which are rotatable between a first position in which the central area is coplanar with the surrounding area and a second positon in which the central area projects perpendicularly to the io surrounding area.

2. A damper as claimed in claim 1, wherein the tubular outer housing is circular cylindrical or rectangular cylindrical.

is

3. A damper as claimed in claim 1 or 2, wherein the mounting bracket is formed by a U-shaped cut track in the sheet material.

4. A damper as claimed in any preceding claim, wherein the mounting brackets are rotatable by plastically deforming a hinge line.

5. A damper as claimed in any preceding claim, wherein the mounting brackets comprise an edge return portion which limits how far the central area can be bent out and provides additional strength.

25

6. A damper as claimed in any preceding claim, wherein the mounting unit comprises a mounting flange and the sheet material comprises the mounting flange.

7. A damper as claimed in claim 6, wherein the mounting flange

30 comprises mounting holes passing through the flange to enable flush surface mounting of the flange, and wherein the flange forms the surrounding area of the mounting brackets.

8. A damper as claimed in claim 7, wherein the mounting holes are formed in the mounting brackets.

5

9. A damper as claimed in claim 7, wherein the mounting holes or further mounting holes are formed in the flange away from the mounting brackets.

10. A damper as claimed in any one of claims 6 to 9, wherein there io are four mounting brackets around the flange.

11. A damper as claimed in any one of claims 6 to 10, wherein the flange is square or rectangular, with one mounting bracket at each corner of the flange.

12. A damper as claimed in any preceding claim, comprising a fire damper.

13. A fire damper as claimed in claim 12, wherein the damper blade 20 is movable between open and closed positions, and the fire damper further comprises:

a biasing member, which urges the damper blade into the closed position; and a retention mechanism for retaining the damper blade in the open 25 position, the retention mechanism being adapted to respond to exposure to temperatures above a threshold temperature by releasing the damper blade so that it is urged into the closed position by the biasing member.

14. A fire damper as claimed in claim 12, wherein the damper blade 30 is movable between open and closed positions, and the fire damper further comprises:

a motor arrangement for driving the damper blade between the open and closed positions; and a control mechanism adapted to respond to exposure to temperatures above a threshold temperature thereby to control the motor arrangement to

5 drive the damper blade to the closed position.

Intellectual

Property

Office

Application No: GB1706186.2 Examiner: Mr David McWhirter