U.S. patent application number 12/736087 was filed with the patent office on 2011-12-29 for device for generating an air wall in an upright refrigerated cabinet.
Invention is credited to Ernest Jozef Elias Berben, Peter Julien Joseph Deweerdt.
Application Number | 20110314857 12/736087 |
Document ID | / |
Family ID | 40934077 |
Filed Date | 2011-12-29 |
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United States Patent
Application |
20110314857 |
Kind Code |
A1 |
Berben; Ernest Jozef Elias ;
et al. |
December 29, 2011 |
Device for generating an air wall in an upright refrigerated
cabinet
Abstract
A device for generating an air wall in an upright refrigerated
cabinet (22) comprises a primary blower slit for generating a
primary air stream (30) in the frontal opening (34) of the upright
refrigerated cabinet which forms a thermal separation between the
low inside temperature and the ambient air of a higher temperature.
No mixing occurs between the primary air stream (30) and the
secondary, optionally forced air streams (1, 9) added thereto. The
thereby realized great effective heat resistance achieves that the
supply of heat from the ambient air to the interior space of the
refrigerated cabinet is considerably limited.
Inventors: |
Berben; Ernest Jozef Elias;
(Poortvliet, NL) ; Deweerdt; Peter Julien Joseph;
(Erembodegem, BE) |
Family ID: |
40934077 |
Appl. No.: |
12/736087 |
Filed: |
March 9, 2009 |
PCT Filed: |
March 9, 2009 |
PCT NO: |
PCT/NL2009/050109 |
371 Date: |
September 12, 2011 |
Current U.S.
Class: |
62/256 |
Current CPC
Class: |
A47F 3/0447
20130101 |
Class at
Publication: |
62/256 |
International
Class: |
A47F 3/04 20060101
A47F003/04 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 9, 2008 |
NL |
2001356 |
Claims
1. A refrigerated cabinet comprising a device for generating an air
wall for thermal separation of the air in a relatively cold first
space, i.e. the interior of a refrigerated cabinet, cold room or
the like for the purpose of cooled self-service presentation of
prepackaged cooled food products, from the air in the relatively
warm second space, i.e. the space surrounding the refrigerated
cabinet or the cold room, which two spaces are mutually connected
via a frontal opening extending in a substantially vertical main
plane and having a height of a maximum of 2 m, the device
comprising: a primary blower slit connecting to a primary blower
unit positioned close to a side of the frontal opening and disposed
substantially parallel to the main plane of the frontal opening,
which slit extends substantially over the whole relevant dimension
of the frontal opening for the purpose of generating an at least
more or less flat primary air stream directed at least roughly
toward the opposite side of the frontal opening, the speed of the
air in the primary air stream amounts to 2-30 m/s; the width of the
primary blower slit lies in the range of 5-20 mm, preferably 8-15
mm; and the length of the blower slit in the direction of the air
stream lies in the range of about 50-150 mm.
2. A device as claimed in claim 1, wherein the blower slit is
divided into blower channels by partitions extending in the air
stream direction.
3. A device as claimed in claim 1, compromising a suction unit
positioned on the opposite side of the frontal opening and having a
substantially prismatic suction slit extending substantially
parallel to the blower slit and having substantially the same
length as the primary blower slit, to which suction slit connect
suction fan means.
4. A device as claimed in claim 3, wherein the primary blower slit
is connected via a duct to the suction slit, in which duct fan
means are disposed which are both the primary blower fan means and
the suction fan means such that the air wall forms part of a
substantially closed circuit.
5. A device as claimed in claim 1, wherein the primary and the
entrained secondary air streams move in vertical direction.
6. A device as claimed in claim 1, wherein at least one of the
secondary air streams is an entrained air stream.
7. A device as claimed in claim 3, wherein the suction slit has a
width and is disposed such that it suctions substantially only the
primary air stream Sp.
8. A device as claimed in claim 3, wherein a number of regularly
distributed, passive control valves are added to the suction slit
for the purpose of equal, constant passing airflows, such that the
same airflow passes at each longitudinal position, such that the
air in the relevant air stream flows substantially in a straight
path at any longitudinal position.
9. A device as claimed in claim 1, wherein the position and
direction of the blower slit is adjustable.
10. A device as claimed in claim 1, comprising at least two
mutually parallel blower slits.
11. A device as claimed in claim 4, wherein the duct is thermally
insulated.
12. A device as claimed in claim 1 for operation in cooperation
with a refrigerated cabinet and adapted to be added to a
refrigerated cabinet.
13. A device as claimed in claim 12, the device being integrated
with a refrigerated cabinet.
14. A device as claimed in claim 1, wherein a curved air curtain of
said refrigerated cabinet runs, among other ways, according to the
Coanda effect relative to the primary air stream.
15. A device as claimed in claim 5, wherein the refrigerated
cabinet is provided with a static evaporator serving as cooling
element, wherein the interior secondary air stream supplies air to
the evaporator.
16. A device as claimed in claim 12, wherein the refrigerated
cabinet is provided with an evaporator with a fan, said evaporator
with fan placed at a bottom or at top of the refrigerated
cabinet.
17. A device as claimed in claim 9, wherein at least two horizontal
air blower slits are placed on the underside and the air coming
from the air slit placed furthest outward is blown out on the top
side in more or less horizontal direction.
18. A device as claimed in claim 16, wherein the air coming from
the outermost air blower slit is supplied to the condenser of a
cooling installation for cooling thereof such that an increased COP
is obtained, for instance an increase from 3 to 8.
19. A device as claimed in claim 1 for operation in cooperation
with a cold room having an air intake and wherein the created
external entrained air stream is drawn in via said cold room air
intake and fed back via fan means to a supply distributing box with
blower slit such that the relevant air stream forms part of a
substantially closed circuit.
20. A device as claimed in claim 1, wherein the air streams are
supplied and discharged via at least one air distributing box,
which is connected to an associated duct of substantially
rectangular cross-sectional form, such that it is possible to place
fan means in one box on the one side on the refrigerated cabinet
and a cooling unit with a cooling group and an evaporator on the
other side.
Description
[0001] The invention relates to a device for generating an air wall
for thermal separation of the air in a relatively cold first space,
i.e. the interior of a refrigerated cabinet, cold room or the like
for the purpose of cooled self-service presentation of prepackaged
cooled food products, from the air in the relatively warm second
space, i.e. the space surrounding the refrigerated cabinet or the
cold room, which two spaces are mutually connected via a frontal
opening extending in a substantially vertical main plane and having
a height of a maximum of 2 m, the device comprising: a primary
blower slit connecting to a primary blower unit positioned close to
a side of the frontal opening and disposed substantially parallel
to the main plane of the frontal opening, which slit extends
substantially over the whole relevant dimension of the frontal
opening for the purpose of generating an at least more or less flat
primary air stream directed at least roughly toward the opposite
side of the frontal opening.
[0002] Such a device is known from WO-A-2006/115824.
[0003] Refrigerated cabinets, for instance upright refrigerated
wall cabinets, and cold rooms are often equipped with an air
curtain which is cooled to a slight extent, wherein the air is
supplied at the top and is extracted at the bottom in order to thus
keep the temperature in the area of the shelves and the bottom at a
determined temperature, for instance in the range of 0.degree.
C.-10.degree. C.
[0004] At the position where the above mentioned refrigerated wall
cabinets and variants thereof are placed the passerby feels the
cold air. As the length and concentration of these refrigerated
wall cabinets increases in a supermarket or other retail space, the
cold can often be felt in every limb in disagreeable manner.
[0005] In the summer this cold is unpleasant for those coming from
an outside summer temperature, and has a negative effect on the
buying behaviour of customers.
[0006] Another drawback is the associated energy loss. One of the
causes of the energy loss is the cold usually flowing or leaking
away on the underside of the air curtain. This is because the air
curtain is not able to form a barrier against the cold layers
accumulating at the bottom.
[0007] Another cause of energy loss is formed by the air vortices
caused by passers-by. Cold likewise leaks away as a result.
[0008] A further adverse side-effect is formed by the occurrence of
an external induction layer along the air curtain, with slow air
stream downward from the top, and where warmer air is likewise
entrained into the air curtain.
[0009] What is often also seen is that air curtains are locally
closed or interrupted by merchandise which has come to lie on the
suction grid of the air curtain. Cold air is hereby also lost and
is generally supplemented by warmer air which must once again be
cooled.
[0010] There are manufacturers of refrigerated wall cabinets who
have already observed this induction layer, such as in
WO-A-2006/115824.
[0011] Other manufacturers apply on the top side a controlled
secondary air stream by drawing in the air for this purpose by
means of fans.
[0012] Other manufacturers in turn wish to combat cold loss by
feeding through the above mentioned secondary air stream on the
underside and at the rear of the refrigerated wall cabinet, and
then drawing in this air again at the top and feeding it back to
the secondary air stream. Whatever the case, a new secondary air
stream of even lower airflow rate will also be created against the
secondary air stream, wherein the described construction can then
be repeated.
[0013] All these solutions have the drawback that the cold losses
are and remain appreciable, with associated energy loss.
[0014] In the light of the foregoing, the invention provides a
device of the type stated in the preamble which has the feature
that
[0015] two secondary entrained air streams Ss1 and Ss2 are added to
the primary air stream Sp on either side thereof, which secondary
entrained air streams have substantially the same direction as the
primary air stream;
[0016] Ts1<Tp<Ts2, wherein: [0017] Ts1=the temperature of the
secondary entrained air stream on the inside, [0018] Tp=the
temperature of the primary air stream, [0019] Ts2=the temperature
of the secondary entrained air stream on the outside;
[0020] the speed of the air in the primary air stream amounts to
2-30 m/s;
[0021] the width of the primary blower slit lies in the range of
5-20 mm, preferably 8-15 mm; and
[0022] the length of the blower slit in the direction of the air
stream lies in the range of about 50-150 mm;
[0023] this such that no mixing occurs between the primary air
stream Sp and the two entrained secondary air streams Ss1 and
Ss2.
[0024] As conditions require, the frontal opening of the
refrigerated cabinet must have single or multiple closure by one or
more adapted air walls with an air stream formed by an air
distributing box at the top along the length of the cabinet, with a
narrow blower slit with a width in the range of about 5 to 30 mm,
and wherein the air is forced to the air distributing box by two
air guiding plates with a length in the flow direction of at least
10 cm. Between these two air guiding plates the air has a speed of
2-35 m/s. When the air stream from this air wall moves for instance
downward from the top, it can then be guided to an evaporator and
subsequently cooled and, via the air distributing box, re-enters
the air wall at the top within the insulated walls of the
refrigerated cabinet. This feedback of air can also be guided below
and behind the cabinet in order to eventually move to the air wall
via the air distributing box.
[0025] The air walls can thus be added to an existing cooled air
cabinet, or the air wall can be built into the cooling circuit in
the refrigerated cabinet.
[0026] In view of the air speed in the air wall, the losses will be
greatly reduced compared to an air curtain.
[0027] This cooled air wall can also operate from the bottom to the
top. A better cold distribution in an upright refrigerated wall
cabinet is hereby obtained. The cool air in the induction flow will
be forced upward unless it is not collected for other purposes.
[0028] The invention has a number of important applications, for
instance:
[0029] 1) an air distributing box for an air wall, which can be
added to an existing refrigerated cabinet. The built-in original
air curtain will herein remain in service (see FIGS. 1-7);
[0030] 2) the construction of an upright refrigerated cabinet. The
air wall is here integrated with the refrigerated cabinet. As the
construction and the necessity require, it is here also possible to
provide another air curtain (see FIGS. 8-11);
[0031] 3) the incorporation of an air distributing box for an air
wall with cold room with open wall adjoining the retail space (see
FIGS. 12, 13 and 14).
[0032] According to a specific aspect of the invention, the device
can have the special feature that the blower slit is divided into
blower channels by partitions extending in the air stream
direction. In the case where use is made of relatively low air
speeds this aspect can be technically particularly significant.
[0033] It is noted in general that the invention is intended for
application in combination with refrigerated cabinets or cold
rooms. It must therefore be understood that everywhere the word
`refrigerated cabinet` is used, this also includes `cold room`.
[0034] The invention will now be elucidated with reference to the
accompanying drawings.
[0035] In the drawings:
[0036] FIG. 1 shows a vertical section through a known refrigerated
cabinet with an air curtain and an entrained secondary air
stream;
[0037] FIG. 2 shows a section corresponding to FIG. 1 to which an
air distributing box is added as device according to the
invention;
[0038] FIG. 3 shows an auxiliary device according to the invention,
intended for addition to an existing refrigerated cabinet;
[0039] FIG. 4 shows a vertical section through a device according
to the invention which generates two air walls;
[0040] FIG. 5 shows a view corresponding to FIG. 3 of an auxiliary
device as according to FIG. 4;
[0041] FIG. 6 shows a vertical section through a device similar to
the device according to FIG. 2, but wherein the relevant air
streams behave partly according to the Coanda effect;
[0042] FIG. 7 shows a vertical section of an arrangement similar to
that according to FIG. 4, but wherein the entrained secondary air
stream is drawn in and circulated;
[0043] FIG. 8 shows a vertical section through a refrigerated
cabinet with a device according to the invention in yet another
embodiment;
[0044] FIG. 9 shows a vertical section through an arrangement
according to FIG. 8, but with a cooled inner circuit and an
evaporator and a fan at the top;
[0045] FIG. 10 shows a vertical section through an arrangement
wherein the air blower slit is situated on the underside instead of
on the top side, and both entrained secondary air streams
individually are utilized effectively;
[0046] FIG. 11 shows a vertical section through a variant of the
embodiment according to FIG. 10;
[0047] FIG. 12 shows a partial vertical section, wherein an air
distributing box is added to an installed auxiliary device as
according to FIG. 3;
[0048] FIG. 13 shows a vertical section corresponding to FIG. 12 of
an embodiment wherein a secondary air stream active in a closed
circuit is applied;
[0049] FIG. 14 shows a vertical section, with partly schematically
designated air streams, of a variant with an air wall in a cold
room adjoining a retail space, wherein the air blower slit is
situated on the underside;
[0050] FIG. 15a shows a partially transparent perspective view of a
further embodiment;
[0051] FIG. 15b shows a partially transparent perspective view of
yet another embodiment; and
[0052] FIG. 16 shows a schematic front view of a refrigerated
cabinet with a device according to the invention as according to
the teaching of FIG. 15.
[0053] Where possible and relevant, use is made throughout the
following description of the drawings of the same reference
numerals for the same or at least functionally corresponding
components.
[0054] FIG. 1 shows an upright refrigerated wall cabinet 22 which
is provided with means for generating an air curtain 1 consisting
of a more or less flat primary air stream with a small thickness
and a high flow rate of 2-30 m/s. Reference numeral 2 designates
the entrained secondary air stream acting on the outside. The air
in the entrained secondary air stream 2 is cooled considerably as a
result of the low flow rate of both air curtain 1 and entrained
stream 2. The cooled air tends to accumulate to some extent in the
area designated with 3 on the front side of cabinet 22 close to
floor 23. The interior space of refrigerated wall cabinet 22
comprises a number of shelves, designated with reference numeral 4,
for holding the food products to be presented for sale. The cabinet
further comprises an evaporator 5 and a fan 6 for cooling the air
flowing by, which circulates in a more or less closed circuit in
the manner shown in FIG. 1. Some of the air in the stream 24
between insulated rear wall 25 and inner wall 26 reaches the space
in the area of the shelves via openings 27.
[0055] FIG. 2 shows an upright refrigerated wall cabinet 28, the
basic configuration of which corresponds to the structure according
to FIG. 1. According to the teaching of the invention however, an
air distributing box 29 is added to said cabinet, this box being
adapted to generate an air wall in the form of a rapid (2-30 m/s)
air stream 30 of small thickness (initial thickness 5-20 mm), which
is situated on the outside relative to slow air curtain 1.
[0056] Air distributing box 29 comprises a fan 31 which draws in
air wall 30 on the underside via an air duct 8 and blows it out
again via a primary blower slit 32 such that a more or less closed
circuit is formed. The speed of the air in this primary air stream
30 amounts to about 15 to 20 m/s. The width of blower slit 32 in
the plane of the drawing is in the order of magnitude of 10-12 mm.
Its length in the flow direction lies in the range of about 50-150
mm.
[0057] The entrained secondary flow on the outside is designated
with reference numeral 2' in order to distinguish it from the
entrained air stream 2 according to FIG. 1, which does after all
flow substantially more slowly.
[0058] Attention is drawn to the fact that air duct 8 is bounded by
the thermally insulating rear wall 25 and an additional thermally
insulating wall 33. Cold losses, and therefore energy losses, are
hereby kept as low as possible.
[0059] FIG. 3 shows the upper part of air distributing box 29.
[0060] FIG. 4 shows the configuration according to FIG. 2, but with
an extension formed by an additional forced secondary outer stream
9 which forms part of an additional more or less closed air
circuit. As the figure shows, the flows of respectively air curtain
1, primary air stream 30, secondary air stream 9 and the outer
entrained secondary air stream 2 move substantially parallel to
each other in the area of opening 34 of cabinet 22.
[0061] Relative to the configuration according to FIG. 2 the
effective thermal insulation in the area of shelves 4 in cabinet
22, which can be expressed as the heat resistance between the
relatively warm exterior space and the relatively warm interior
space, will thus be even greater in the configuration according to
FIG. 4, which is already better than in the configuration according
to FIG. 2.
[0062] FIG. 5 shows that the multiple air distributing box 35 not
only comprises the fan 31 for primary air stream 30, but also an
additional fan 36 for the outer secondary fan.
[0063] FIG. 6 shows a configuration in which a refrigerated cabinet
37 is also provided with a lighting fixture 11. As clearly shown in
the drawing, air curtain 1 departs from its normal linear path as a
result of the suction of an induction air stream by primary air
stream 30 according to the teaching of the invention. There is
therefore a dual effect, i.e. on the one hand the suction as
entrained air stream and on the other hand the Coanda effect,
wherein air curtain 1 begins to behave as such an air stream. Since
the configuration otherwise corresponds to that according to FIG.
2, the description of the other components is omitted here.
[0064] FIG. 7 shows a configuration wherein the second entrained
air stream 10 is drawn in and circulated together with the first
entrained air stream 9. The quantity of air which is drawn in on
the underside must be discharged via an air outlet 12 such that the
balance is guaranteed.
[0065] FIG. 8 shows a configuration wherein the air is cooled by an
evaporator 5 placed in the top part of the cabinet together with an
associated pressure fan 13. Cold air is carried downward via an
adjustable opening 14 for the purpose of cooling the food products
held by shelves 4.
[0066] FIG. 9 shows a configuration which is related to that
according to FIG. 8 but which has a cooled inner circuit,
comprising an evaporator 38 and a fan 39, both of which are
arranged on the top side.
[0067] FIG. 10 shows a configuration with an upright cooled
refrigerated wall cabinet, according to which configuration the
primary stream in the air wall according to the invention flows
upward from the bottom. The entrained secondary air stream 16
flowing on the inside also flows upward, whereby the possible
"falling" cold air likewise flows upward. This air stream then
passes the static evaporator 17. The cooled air coming from
evaporator 17 automatically moves downward and reaches the space
with shelves 4 via openings 27. In this configuration the pressure
fan 13 is drawn on the underside. There is no technical reason for
this per se; it could be placed on the top side with the same
effect.
[0068] The entrained secondary air stream 18 situated on the
outside also moves upward. At the top this air can be used to cool
the condenser of a cooling group 19 placed there. The COP of the
installation is hereby increased even further.
[0069] FIG. 11 shows a configuration which can be deemed a variant
of the configuration according to FIG. 10. A ventilated evaporator
5 with a low-pressure fan 6 is applied instead of static evaporator
17. In this embodiment the closed air circuit takes roughly the
same form as in the configuration according to FIG. 10.
[0070] FIG. 12 shows an arrangement wherein an air distributing box
29 according to FIG. 3 connects substantially to wall 40 of a cold
room 41 adjoining a retail space 42.
[0071] An entrained secondary outer air stream 20 also results in
the manner shown in this embodiment.
[0072] FIG. 13 shows a variant of the arrangement according to FIG.
12, in which is shown schematically that an outer entrained air
stream 21 forms part of a closed circuit, comprising a blower unit
43 on the top side, a suction unit 44 on the underside, this
suction unit being connected to the blower unit via a schematically
drawn bypass 46 with a fan 45.
[0073] FIG. 14 shows schematically a variant with an air wall,
which is based on a rapid, thin primary air stream 30 according to
the invention, in the entrance opening of a cold room 41 adjoining
a retail space 42, which flow 30 moves upward. The arrangement is
closely related to that according to FIGS. 10 and 11. This relation
is also manifest in the shown pattern of secondary streams 16 and
18.
[0074] In the configurations according to the above discussed
embodiment according to the invention the relevant air streams are
transported via elongate air blower slits, the length of which
largely corresponds to the associated dimension of the relevant
refrigerated cabinet. In order to save energy use could also be
made of smaller ducts to carry cold air to the relevant location
and to discharge it. This is also the case for the air
distribution. This could imply that it is possible to suffice with
placing units to the left and right relative to the cabinet. Nor is
necessary under all circumstances to arrange multiple insulating
layers in the cabinet. Omission thereof makes the construction of a
cabinet simpler and cheaper, albeit with the likely drawback of a
slightly lower efficiency.
[0075] FIGS. 15a and 15b show variants of refrigerated cabinets to
which air wall devices according to the invention are added.
[0076] FIG. 16 shows a front view of a refrigerated cabinet with a
device according to the invention, which is provided with shelves 4
for holding products to be presented for sale.
[0077] According to the invention the air wall can be applied in
single arrangement to thermally separate the relatively warm
ambient air from the relatively cold air in the interior of a
refrigerated cabinet or cold room. If the temperature difference
over this single air wall is small, there will be little heat
loss.
[0078] In the case where two parallel air walls according to the
invention are placed, the heat losses per applied air wall will
decrease still further.
[0079] If a further secondary air stream fed by indrawn air is
applied in the same direction in the case of a single air wall or
two or more parallel air walls, an exceptionally small heat loss is
then realized. Such add-ons must be balanced against the power
required for the pressure fan which must be applied for each forced
air stream.
[0080] Should it be wished to place an air distributing box for air
walls on the top side of the refrigerated wall cabinet, the
elongate lighting fixture may then be in the way. In this case it
is possible to remove the lighting unit, position the outlet of the
air distributing box there, and subsequently place the lighting
unit thereon. It is usually necessary in this case to ensure that
the direction of the air blower slit is adjustable, namely such
that the primary air stream exits at the bottom edge of the
cabinet. The intention here is to separate the cooled internal air
stream circuit from the air wall.
[0081] The advantages of the invention can be summarized briefly as
follows:
[0082] 1) There is a high effective heat resistance at the position
of the vertical opening, whereby energy losses are greatly
limited.
[0083] 2) The temperature in the interior space of the refrigerated
cabinet can be better maintained within narrow limits.
[0084] 3) The construction according to the invention is simple,
inexpensive and effective.
[0085] 4) A refrigerated cabinet can suffice with a smaller cooling
installation and therefore be cheaper.
[0086] 5) Existing refrigerated cabinets can be supplemented with a
unit according to the invention, whereby replacement of existing
and still very serviceable refrigerated cabinets is not
necessary.
[0087] 6) It is possible to realize a higher COP by using air from
an entrained secondary air stream for the purpose of cooling a
condenser.
[0088] 7) The invention can also be applied when selling from cold
rooms.
[0089] 8) The structure according to the invention can also be
applied in the case where a lighting fixture is situated inside the
cooled space.
CITED LITERATURE
[0090] WO-A-2006/115824
* * * * *