The invention relates to a fitting for suspending a supply-air
terminal device on a flat support surface, of the kind that is seen in the preamble
of the appended claim 1.
Fittings for suspending supply-air terminal devices of
the kind that is defined in the preamble of claim 1 are known from practice.
An object of the invention is to provide a fitting that
affords a simple and convenient suspension of the supply-air terminal device, and
furthermore affords favourable conversion of the flow of supply air and room air
conveyed thereby that flows away from the supply-air terminal device toward the
A special object is to provide a fitting that can afford
an additional fine adjustment of the flow pattern of the air flows leaving the area
of the supply-air terminal device.
The objects are entirely or partly attained by the invention.
The invention is defined in the appended independent claim.
Embodiments of the invention are defined in the appended
In the following description, a presently particularly
preferred embodiment of the invention is accounted for.
- Fig. 1
- schematically shows a vertical section through a room having a supply-air terminal
device that is suspended on a wall by means of a fitting.
- Fig. 2
- schematically shows a view taken along the line II-II in Fig. 1.
- Fig. 3
- shows the fitting according to Fig. 2 having another setting of a fitting fin.
Fig. 1 schematically illustrates a room 1 having a wall
2, which, by means of a fitting 3, carries a supply-air terminal device 4, which
is supplied with supply air 5 via a supply-air pipe 6. The supply-air terminal device
4 has a plurality of nozzles 40, which generally direct the supply air toward the
fitting 3 on the wall 2. When the supply air 5 has a lower temperature than the
air of the room 1, the supply air will be mixed with the room air while forming
a thin air layer 7, which flows downward along the wall 2 and then is deflected
along the floor 8 and stratifies on the same. A relatively warm object 9, which
is impinged by the air 7, will then be cooled and the accordingly heated air flow
7' rises upward in the room 1 in order to finally escape via an exhaust-air pipe
10 in the ceiling 11 of the room, in a manner known per se.
From Fig. 2, it can be understood that the fitting 3 is
mounted so that it rests directly against the wall 2 and has a central nut groove
31, the bottom of which rests against the surface 2 and the opening 32 of which
is facing the interior of the room and the centre of the supply-air terminal device
4. The supply-air terminal device 4 is in the form of a circular-cylindrical pipe
section having an end cap 42 and an inlet end that coaxially connects to the pipe
6. The mutually alike nozzles 40 are shown formed on the outside of the section
4 and are shaped as venturi nozzles in order to, with a minimized noise generation,
allow air to flow out at a speed of at least 10 m/s and preferably 12-15 m/s through
the respective nozzle. Each nozzle can have a smallest flow diameter of approx.
5 mm. The section 4 can have a diameter in the range of 10-40 cm, and preferably
has the nozzles 40 thereof arranged with the nozzles in longitudinal rows, the rows
having an interspacing in the circumferential direction of approx. 2 cm. A diametrical
plane through the section 4 and the width centre of the fitting 3 extends halfway
between two rows of nozzles. In the example, the section 4 has totally six rows
of nozzles, wherein the spacing between the nozzles in the rows also may be approximately
The fitting 3 is shown to have a groove 31, the bottom
of which rests against the surface 2 and the opening gap 32 of which is facing the
supply-air terminal device 2. The groove 33 is shaped to receive nuts 50 in a rotationally
secured way, so that the nuts 50 can be displaced along the groove 33. Bolts 51
extend through appurtenant holes 44 in the section 4 and have the head 52 thereof
on the inside of the section 4. The bolt shank 51 has the threaded free end thereof
received in an appurtenant nut 50. Possibly, the bolt shank 51 may be full-threaded
and carry a lock nut (not shown) in order to enclose the wall of the pipe section
4 between the lock nut and the bolt head 52. The fitting 3 is shown to comprise
rings 34 that extend outward from the free edge parts of the groove 33, in opposite
directions. Along the free edge thereof, the wings 34 have a first swivel-joint
portion 60, which receives a second swivel-joint portion 61 along one of the long
edges of a fin 70, the other long edge of which has a swivel-joint portion 60 of
the same design as the swivel-joint portion 60 of the wing 34. In this way, an additional
fin 70 may be connected by the portion 61 thereof to the shown free joint portion
60 of the fin 70 shown. The swivel joint 60, 61 is per se of a standard design,
which may be locked in respect of swivelling by the fact that a plastic plug, including
an appurtenant expander screw, is inserted in the axial end of the swivel joint.
At the outer end thereof, on the side thereof facing the
section 4, the fin 70 carries a border 72, which is directed inward toward the groove
33 and forms an acute angle &agr; with the main part of the fin 70. The angle
&agr; is shown to be about 45°, but may be selected in the interval of 30-60°.
The joint portions 60 of the wings 34 are tangent to the flat support surface 2.
The fitting 33 may be attached by fixing screws, not shown, which extend through
the bottom of the groove 33 into the support 2.
The section 4 is suspended at the fitting 3 by means of
at least two bolts 51.
It will be appreciated that the fins 70 may be angularly
preset in relation to the wings 34 and be locked in the set turning position. When
the supply-air flows 45 through the respective nozzle 40 leave the nozzles 50, they
produce an ejector effect and convey room air 80 that can flow along the external
surface of the section 4 between the external wall thereof and the outer ends of
the nozzles 40, each flow 45 conveying a partial flow 81 of room air from the room-air
layer 80 and is mixed with the same. In practice, each air flow 45 may mix with
an up to four times larger room-air flow 81. From Fig. 2, it can be understood that
the total width of the fitting 3 is approximately as large as the circumference
spacing between the rows of the nozzles 40 that are most spaced-apart in the circumferential
As is seen in Fig. 2, the fitting and the parts of the
wings 34 connecting to the groove 33 have the greatest distance from the reference
surface 2, and the wings 34 have the smallest distance thereof to the reference
surface 2 at the joint device 60, 61.
Usually, the fins 70 are folded down against the surface
2 in order to, together with the respective wing 34, form a guide rail for the flow
of mixed supply air and room air established outside the nozzles 40. Since the fins
70 have equal turning positions in relation to the adjacent wing 34, approximately
equal flows are deflected along the respective wing 34, but the balance between
these flow parts can be regulated by altering the turning positions of the fins
70. When the fin 70 is turned out toward the supply-air terminal device 4, the border
72 presents a particularly strong resistance against the mixed air flow flowing
along the wing 34 and the fin 70. If the fin 70 at the opposite side of the fitting
simultaneously is turned out closer to the reference surface 2, it is possible to
alter the flow pattern, so that the main part of the mixed air flow flows along
the fitting past the fin 70, which is maximally turned out toward the support surface
2. By altering the mutual turned-out positions of the fins 70, there is a possibility
of a far-reaching selectable distribution of the total mixed air flow deflected
to a thin layer close by the plane, toward the respective side of the fitting 3.
The distance between the fitting 3 and the supply-air terminal
device 4 is approximately half the maximal width of the fitting 3 such as is shown
in Fig. 2.
The fitting forms a guide surface for the mixed air flow
and has suitably the same length as the supply-air terminal device, i.e., approximately
the same length as the rows of nozzles 40 of the piping section 4.
The groove and the wings as well as the joint portions
belonging to the wings are suitably manufactured as an extruded profile element,
for instance of aluminium, which hence can be cut off into lengths corresponding
to standard lengths of the supply-air terminal devices. Likewise, the fins may be
formed of extruded profile elements that are cut off into the same length and joined
to the wing and to each other, respectively.
From Fig. 2, it can be understood that the rows of nozzles
are approximately equally interspaced, the outermost rows of nozzles having an interspacing
of approximately 10 cm along the circumference. The connecting elements that join
between the supply-air terminal device and the groove of the fitting have approximately
the same length independently of the diameter of the supply-air terminal device,
and this means that the fitting, while essentially retaining the function thereof,
can be utilized for supply-air terminal devices of many different diameters, from
approx. 10 cm up to, for instance, 50 cm or more.
Such as is outlined in Fig. 2, the fitting 3 may be attached
to the support surface 2 by means of screws extending through the bottom of the
groove 33 and into the support 2, the heads of the screws suitably being countersunk
in the bottom wall of the intermediate portion 33.
From Fig. 2, it can be understood that the central fitting
part, comprising the intermediate portion 33, the wings 34 and the joint portions
60, has a width that essentially corresponds to two thirds of the circumference
extension of the field of nozzles 40. Furthermore, it can be seen that the wings
34 converge in relation to the wall/ceiling surface 2, from the mouth 34 of the
intermediate portion 33 toward the outer long edges thereof, the converging angle
being shown to be small, approx. 5°, and wherein the angle should be in the
range of 3-20°. Thus, the fitting affords, even without fins, a favourable
uniform deflection of the flow of supply air and room air so that this forms two
substantially equal counter-directed partial flows, which get the form of thin layers
flowing along and next to the wall surface 2, without said partial flows substantially
disturbing the adjacent room-air mass.
The mountings of the fins 60, 61 allow the fins to be turned
up to a limit position, where they are positioned approx. 45° from the plane
of the wings. In this way, the fins can be utilized to produce controlled flow shares
along the respective wing.
Thanks to the speed of the air jets through the nozzles
40, a kind of ejector effect is attained around the air jets exiting the nozzles,
whereby room air from the area around the respective nozzle being conveyed and intermixed
into the supply-air jet exiting the nozzle. A relatively large share of room air
is intermixed into the respective supply-air jet, and is conveyed by the same toward
the fitting. The room air that is sucked into and mixed with the respective supply-air
jet flows diffusely from the interior of the room toward the side of the piping
section exposed to the room, and flows along the circumference of the piping section
into a space between the external surface of the pipe section and a surface defined
by the mouths of the nozzles 40.