[0001] The invention relates to a cooling device for use in ale coolers, automatic beverage
machines, air-conditioning apparatus or the like, said cooling device mainly comprising
a series-connected evaporator, a compressor, a lamella condensor and an air displacing
member for generating a cooling air stream along the condensor lamellae.
[0002] Such a cooling device is usually incorporated in bars or cabinets and the like and
are, therefore, difficult of access for cleaning purposes. This is particularly troublesome
in cleaning the lamellae of the condensor, which has to be done at regular intervals
because the air stream carries along an amount of dust and/or dirt which settles on
the lamellae of the condensor. Filthiness of the condensor brings about a decrease
in refrigerating capacity of the condensor so that the compressor has to run longer
for the required cooling effect and the energy consumption of the device increases.
Moreover, with an increasing fouling the compressor pressure tends to increase to
an extent such that the compressor motor coils may burn through.
[0003] The invention has for its object to obviate the aforesaid disadvantage by providing
a cooling device which is distinguished by means for inverting the direction of flow
of the cooling air along the condensor lamellae.
[0004] Owing to this inversion of the cooling air stream the dust deposited on the lamellae
is blown back and conducted to the outside.
[0005] In one embodiment the air displacing member is constructed in the form of an axial
blade rotor driven by a polarity commutating electric motor and the inverting means
in the form of an electric switch controlled by a cycle generator. The cycle generator
provokes an inversion of the polarity circuit in the electric motor so that the latter
starts rotating in the reverse direction and owing to the opposite direction of rotation
the axial blade rotor blows the air back.
[0006] In a further embodiment the air displacing member is formed by an axial blade rotor
driven by a polarity commutating electric motor, in which the inverting means are
formed by a switching mechanism for varying the position of the blades of the rotor.
[0007] According to a further aspect the air displacing member is an axial or a radial rotor
connected with a channel system that can be blocked by flaps and conducting to both
sides of the condensor, said flaps being controlled by a time control. The flaps are
disposed so that either one channel or the other is opened so that either one side
or the other of the condensor is linked to the rotor.
[0008] It is preferred to control at the same time the thawing cycle of the evaporator by
means of the cycle generator or the time controle so that during thawing of the evaporator
the cooling air stream across the condensor is inverted and the condensor is blown
clean.
[0009] When the sense of rotation of the rotor or, respectively, the setting of the blades
of the rotor is inverted, it is preferred to use a higher rotor speed than during
the normal cooling cycle.
[0010] The invention will be described more fully with reference to a few embodiments.
[0011] The drawing shows in:
Fig. 1 a perspective view of a refrigerator for bottles comprising a cooling device
embodying the invention,
Fig. 2 a schematic view of the cooling device employed in the refrigerator of fig.
1,
Fig. 3 and 4 two circuit diagrams suitable for use in the cooling temperature control
for the compressor,
Fig. 3a an alternative circuitry comprising a series-connected temperature control
for the compressor motor
Fig. 5 a further embodiment of a condensor with a rotor and a channel system for the
cooling air.
[0012] The refrigerator 1, shown only by way of example, comprises spaces 2 to the front
for holding, for example, bottles. The spaces are cooled on the top side by a cooling
element or evaporator 3 of a conventional kind, in which a fluid is circulating by
means of a compressor 4. In the fluid circuit is included in series a condensor 5,
in which the heat withdrawn from the compartment 2 is transferred to the ambient air.
In order to increase the capacity of the condensor 5 it is equipped with lamellae,
an air displacing apparatus 6 being provided to blow an air stream along the lamellae.
[0013] Fig. 2 schematically shows the arrangement, the same reference numerals being used
for corresponding elements.
[0014] The invention now proposes to periodically invert the normal cooling air stream in
the direction indicated by the arrow P1 (see the arrow P2) in order to blow back the
dust or dirt particles back.
[0015] The air stream can be inverted in various ways, for example, by means of an electric
switching system, which is described more fully with reference to figs.3 and 4.
[0016] For such a system the driving motor of the air displacing member formed by a blade
rotor has to be com- mutatable in polarity for inverting the direction of rotation
of the rotor in the electric motor. Such a polarity commutating motor is designated
by reference numeral 10 in figs. 3 and 4. The change-over of polarity is performed
by means of an electric switch 11, which is controlled by a cycle generator 12. The
cycle generator may be of a conventional type, for example, a switching roller or
an electronic switching block. The switching block has a definite time constant so
that after a given period, for example, of six hours the switch 11 remains changed
over for 15 minutes, the sense of rotation of the rotor in the elctric motor then
being inverted as a result of which direction of flow of the air along the lamellae
of the condensor 6 is also inverted.
[0017] When the cycle generator 12 only controls the electric motor 10, the cooling device
may be used, for example, in an ale cooler because no thawing cycle is required in
this case. This is illustrated in the diagram of fig. 4.
[0018] Fig. 3 shows a circuit diagram in which the cycle generator 12 controls, in addition,
a switch 13 of a compressor 14. In such an embodiment the cooling device may employed,
for example, in the refrigerating system of fig. 1, in which a thawing cycle has to
be periodically carried out in order to remove ice depositions on the evaporator.
For this purpose the cycle generator can each time cut off the compressor and during
this period the blower is automatically inverted for blowing the condensor lamellae
clean.
[0019] For completeness' sake a safety thermostat for the compressor is shown at 15. Reference
numeral 16 designates an electric blower motor which serves, for example, for transporting
the cooled air in the compartment of the refrigerator or for driving a stirrer.
[0020] Fig. 3a shows a temperature-controlled motor of the compressor, in which the setting
30 tends to maintain a given temperature in the cooling space by the control means
of the control-block 31. When the given temparature is reached, the switch 33 of the
compressor motor 14 is cut off by the solenoid 32 so that the cooling process stops.
As soon as the temperature sensor 34 detects a deviation in the cooling space the
block 31 re-actuates the motor 14 through the solenoid 32.
[0021] Independently thereof the cycle generator 12 brings about the desired thawing and
cleaning cycle respectively of the cooling space or the lamellae of the condensor
respectively. The latter process described is achieved by inverting the polarity commutating
motor.10. By changing over the switch 11 the motor is controlled, whilst the switch
35 puts the solenoid 32 out of operation so that the switch 33 is changed over and
the compressor motor 14 is switched off. This control illustrates that even in periods
in which cooling is necessary for a long time and the compressor motor 14 is continuously
running for a long time the thawing and cleaning processes are nevertheless ensured
thanks to the cycle generator, which results in a decrease of the overall energy expenses.
[0022] Fig. 5 is a schematic view for a mechanical inversion of the air stream along the
lamellae of the condensor 20, on both sides of which is connected a channel system.
The channel system conducts to a radial blade rotor 21, which can be rotated by an
electric motor (not shown). Each channel 22 and 23 is provided with a flap system
24 and 25 respectively, which can be turned over by a mechanical leverage 26 (see
the solid and broken lines respectively in the figure). The leverage 26 may be biassed
by a tensile spring 27 and it can be shifted by a solenoid 28 acting against the tensile
strength of the spring 27. The solenoid can be energized by a time control, for example,
the cycle generator 12 of figs. 3 and 4.
[0023] From this figure it will be apparent that in one position of the leverage channel
23 communicates with the blower 21, whereas channel 22 communicates with the open
air and that after a change-over channel 22 communicates with the blower and channel
23 is opened to the ambience.
[0024] The invention is not limited to the embodiments described above.
1. A cooling device for use in ale coolers, automatic beverage machines, air-conditioning
apparatus or the like, mainly comprising a series-connected evaporator, a lamella
condensor and an air displacing member for generating a cooling air stream along the
condensor lamellae characterized by means for inverting the direction of flow of the
cooling air along the condensor lamellae.
2. A cooling device as claimed in claim 1, characterized in that the air displacing
member is constructed in the form of an axial blade rotor driven by a polarity commutating
electric motor, whilst the inverting means are formed by an electric switch controlled
by a cycle generator.
3. A cooling device as claimed in claim 1, characterized in that the air displacing
member is an axial blade rotor driven by an electric motor and provided with displaceable
blades, the inverting means mechanically changing the blade position of the rotor.
, 4. A cooling device as claimed in claim 1 characterized in that the air displacing
member is an axial or radial rotor with which communicates a channel system that can
be blocked by flaps and that conducts to both sides of the condensor, the flaps being
controlled by a cycle generator or a time-control.
5. A cooling device as claimed in anyone of the preceding claims characterized in
that the cycle generator or the time-control controls, in addition, the thawing cycle
of the evaporator.
6. A cooling device as claimed in anyone of the preceding claims characterized in
that the speed of the rotor of the air displacing member if higher during the inverted
operation than the nominal speed during the cooling cycle.