Note: Descriptions are shown in the official language in which they were submitted.
A device for controlling and closing gas flows
The invention relates to a device for controlling and
closing gas flows in an air-conditioning plant.
An air-conditioning plant has usually the following sepa-
rate devices designed for controlling and closing the air
flow
- fresh-air closing damper
- exhaust-air closing damper
- circulation-air dampers
- control damper and bypass damper of the heat recovery
exchanger
Usually the control, closing and bypass dampers are louver-
structured and are made up of a number of louver blades
installed adjacently on parallel turning shafts so that in
the closing position the louver blades together form a
plate covering the air aperture and in the open position
they rotate onto planes parallel to the flow and forrn
numerous through-flow gaps in the manner of venetian
blinds.
A previously known device of another type (not louver-
structured) is disclosed in patent application FI-8~1 809.
The said device comprises a heat recovery device, a heat
exchange cell, an incoming-air inlet, and means for closing
the bypass-conduct air inlet selectively in different turn-
ing positions, and it is intended only for use as control
and bypass means for a heat recovery exchanger.
Present-day air-conditioning plants re~uire separate
dampers, e~uipped with their own damper motors, for closing
the inlet and exhaust air flows, ~or controlling the bypass
2~
air flow and ~or the control and bypass of the heat re-
covery exchanger. The greatest disadvantage is undoubtedly
the large number and space requirement of the dampers and
the damper motors, as well as the amount of installation
work required.
The difficulty of sealing the louver-structured closing
dampers has also been a significant disadvantage up to now,
since the closing means is made up of a plurality of louver
blades which must all be made air-tight in relation to one
another and also on all their sides in relation to the
device frame or body.
The device according to the invention provides a crucial
improvement with respect to the disadvantages presented
above. To realize this, the device according to the inven-
tion is characterized in what is disclosed in the charac-
terizing clause of Claim 1.
It can be regarded as the most important advantage of the
invention that the number of devices required in the air-
conditioning plant and the space re~uirement of the devices
are reduced. It is a further advantage that the reduced
number of devices increases the operational reliability of
the alr-conditioning plant without reducing its functions.
The operational reliability and precision are further in-
creased by the eact that the sealing of the dampers of the
device accordiny to the invention is good and reliable.
The invention is described below in detail with reference
to the accompanying drawings.
Figure 1 depicts partially sectional side and plan views oE
an embodiment of the device according to the invention.
Figures 2 - 5 depict the application of the embodiment
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depicted in Figure 1 as a control and closing device o-f an
air-conditioning plant, in the various states of operation
of the device.
The device according to the invention has two or more con-
trol dampers la - c, 8, intended for the control of gas
flows and interconnected by means of levers 3, the angle
between the fully open and the fully closed posikions of
the dampers being ~ or B, which is preferably 45D. The
control dampers la - c, 8 may in total move over an angle
of 2A, since in this case angle A = angle B, i.e. prefer-
ably 90, in which case the position of the dampers is
shifted from the first fully closed position 9 via the
fully open position 10 to the other fully closed position
11 .
The embodiment of Figure 1 thus has a total of four control
ducts for air flows 7a - c and 12, the ducts being in this
case separated from one another by partitions 13 and from
the exterior by end walls 14 and a side walls 15. The air
flows travel through the device in parallel and under the
control of the duct side walls 15 and partitions 13 or,
respectively the end walls 14. Each control duct thus has
preferably one control damper la - c or 8, which in the
fully open position is parallel to the corresponding air
flow, in which case angle a = 0. From this, the control
dampers can be turned ln one direction, whereupon angle a
approaches the angle a = -~A of the Eirst closed position,
or in the other direction, whereupon the angle a approaches
the angle a = -A (i.e. = B) of the other closed position.
The apparatus according to Eigure 1 as a whole thus func-
tions as follows:
In the position which closes air flows 7a - c, 12, all the
control dampers la - c, 8 are in the fully closed position
(a = +A, preferably ~5;
when the control levers 3 are turned to the position 45 or
over some other structural angle, the other control dampers
la - c, with the exception of the control damper 8 of the
so-called bypass duct (still fully closed, a = +A) are
fully open (a = 0);
when the control levers 3 are turned further over the same
45O or an angle according to some other corresponding
structural dimensioning (thus, for example, in total 0 -
>90), the other control dampers la - c move further to the
other fully closed position (~ = -A = B) and the control
damper 8 of the bypass duct opens into the fully open posi-
tion (a = 0).
The closing and control dampers are sealed against the
partitions 13 and respectively end walls 14 either by means
of sealing flanges or sealing strips 6 and against the side
walls 15 by means of sealing flanges or sealing strips 2. A
spring 4 or a counterweight ensures that the control damper
of the bypass duct remains closed and is air-tight.
The control and closing damp~rs are turned by mediation of
shafts 16 rigidly fastened to tha levers 3, each damper
turning about its own shaft 16. The opposite ends of ths
levers 3 are mounted with bearings 30 to a bar 17 or its
articulation part 18. A drive device such as a motor 5 is
attached to one of the shafts 16 to rotate the said shaft.
Through the transmission of the bar 17 also the other
shafts 16 rnounted with lever 3 to the bar 17 also rotate in
the corresponding manner. If the lever 3 is mounted on
bearings to the articulation part 18, which for its part is
fastened to the bar 17 with a clearance, for example by
mediation of a groove 19 in it and a pin 20 in the bar 17,
fitted in the groove, the damper 8 on the shaft in question
turns only over the extent of that movement of the bar 17
which extends beyond the clearance. In this manner a phase
difference is accomplished between the movement of the
damper 8 and the movement of the other dampers la - c. In
the embodiment of Figure 1 the phase difference or lag is
of the magnitude of angle A (i.e. preferably 450).
Preferably the shafts 16 are located in the middle of the
dampers 1 or respectively 8, transversely in relation to
the flow, to minimize the moment produced by the flow.
When the device according to the invention is applied to
the heat recovery unit of ventilation, the unit comprising
a plate heat exchanger operating according to the cross
~low principle, and its bypass duct, two control and clos-
ing devices described above (Figure 1) are used. This con-
trol and closing device unit is shown in Figures 2 - 5. For
the sa~e of clarity, only the control and closing devices
according to the invention are shown as a whole but the
heat exchanger and other conventional components are not
shown.
Figure 2 depicts a situation in which the air-conditioning
plant is stopped and the device according to the invention
is closlng the flows of both exhaust air and incoming air.
All control dampers 21a - c, 31a - c, 28, 38 are in their
fully closed positions.
Figure 3 depicts a situation in which the air-conditioning
plant is in operation and the exhaust air P and the in-
cominy air T are Elowing throuyh the heat exchanger. The
control dampers 21a - c, 31a - c located at the heat ex-
changer are in their fully open position and the control
dampers 28, 38 at the bypass duct are in their ~ully closed
position, thereby closing the bypass-flow duct.
z~
Figure 4 depicts a sltuation in which the air-conditioning
plant is in operation and exhaust air P is flowing -through
the heat exchanger and incoming air T is flowing through
the bypass duct of the heat exchanger. The exhaust-air
control dampers 31a - c at the heat exchanger are in their
fully open position and the exhaust-air control damper 3
at the bypass duct is in its fully closed position. The
inlet air control dampers 21a - c at the heat exchanger are
in their fully closed position and the inlet-air control
damper 28 at the bypass duct is in its fully open position.
Figure 5 depicts a situation in which the air-conditioning
plant is not taking in fresh air. At the heat exchanger all
the control dampers 21a - c, 28 for inlet air T are in
their fully closed position. At the heat exchanger the
control dampers 31a - c for exhaust air P are in their
fully closed position and at the bypass duct the exhaust-
air control damper 38 is in i.ts fully open position. The
air-conditioning plant is in this case in circulatlon-~ir
use.
The invention is, of course, suitable for use also in other
than air-conditioning plants as a device for dividing gas
flows and as a bypass, control and closing device in var-
ious apparatus.
Depending on the use, there may be two, three, four or more
control and closing ducts. The angle of movement of the
control and closing dampers can be selected according to
the situation, in which case angle A, i.e. the angle be-
tween the fully closed posi.tion and the fully open posi-
tion, may at its smallest be only a few degrees and at its
largest 90. At its most advantageous it is within the
range 30 - ~0, and specifically 45. The angle between the
fully closed positions is typically double the above-men-
tioned angle, i.e. 2 x A, in which case angle A ~ angle B.
It can, however, be thought that the movement on the two
sides of the open position would be asymmetrical or that
the closing in one direction would take place against a
separate flange, in a manner different from that in the
other direction, in which case angle A = angle B and the
angle between the fully closed positions would be A + B.
The lever mechanism can also be designed according to need
by using various lever and camshaft mechanisms to connect
the levers 3 to each other and to the drive apparatus. By
applying both an asymmetrical movement or closing of the
damper and various lever mechanisms the device according to
the invention can be made to perform even complicated con-
trol functions with only one drive device or with a consid-
erably smaller number of drive devices, and simpler drive
devices, than is conventional.
