FIELD OF THE INVENTION
[0001] This invention relates to a refrigeration transport container.
BACKGROUND TO THE INVENTION
[0002] Refrigerated transport containers are widely used in industry to transport fresh
produce. Fruit and vegetables need to be kept at reduced temperatures to maintain
the freshness, and in so doing the shelf-life and marketability thereof. Rigid rules
regulate the temperature at which, for example, the fruit or vegetables are transported
at. If the required temperature is not maintained, the container of fresh produce
may be rejected and thus discarded. This can lead to large losses for the supplier.
Homogenous, controlled cooling of the contents of refrigerated containers is thus
essential.
[0003] Refrigeration containers typically have a standard configuration with a refrigeration
unit located at one end of the container opposite the doors. The refrigeration unit
is typically located behind a panel with openings provided at the top and bottom of
the panel. Air from the interior of the container is drawn through the opening at
the top of the panel into the refrigeration unit and cooled air blown into the container
through the opening at the bottom.
[0004] Standard refrigeration containers also have a floor formed by spaced apart T-sectioned
extrusions which run the length of the container from the refrigeration unit to the
doors. This is often referred to as a "T-bar floor". With the container loaded with
produce, cooled air exiting the refrigeration unit is intended to flow between the
extrusions along the length of the floor and then up through the produce before being
drawn back into the refrigeration unit. In practice, however, the cooled air flows
only very weakly near the door end of the floor as it tends to short-circuit from
the outlet to the inlet through gaps between the produce and the sides of the container,
and through gaps in the produce near to the outlet. This results in the produce not
being homogenously cooled and particularly the produce adjacent the doors often being
insufficiently cooled.
[0005] South African patent number
2009/00716 proposes a refrigeration container in which short-circuiting of cooled air is avoided
by covering the conventional T-bar floor with a sheet of metal which leaves an opening
adjacent the doors, and through the use of baffles between the produce and the sides
and roof of the container. The baffles take the form of inflatable bags or strips
of a flexible plastics material. Cooled air thus travels from the refrigeration unit
along the floor of the container and enters the container near the doors whereafter
it is forced to flow through the produce before reaching the air inlet at the opposite
end of the container. Although the container proposed in this patent appears to work
effectively, it suffers the disadvantage that the baffles are cumbersome and inconvenient
to install. Furthermore, the cooled air flowing along the floor of the container will
tend to absorb heat from the floor and thus provide less efficient heat transfer with
the produce once it enters the container. This in turn will require a higher volume
of cooled air to be generated and circulated.
[0006] Although the containers described above are what are commonly referred to as "shipping
containers", a virtually identical internal design is used for refrigerated containers
which are built integrally with road transport vehicles, either as self-propelled
vehicles or trailers. In this specification "refrigeration transport container" shall
have its widest meaning and include shipping containers and those forming part of
road transport vehicles.
[0007] WO 87/00808 discloses a heat insulated freezing box having a refrigeration system at its front
and an intermediate ceiling that stretches from the front to the rear end of the box
such that a channel is formed between the ceiling and intermediate ceiling of the
box.
WO 87/00808 does not teach the use of a barrier to prevent cargo from being stacked too close
to the air outlet nor the use of a barrier to direct air flow upward and then horizontally
into the cargo space.
OBJECT OF THE INVENTION
[0008] It is an object of this invention to provide a refrigeration transport container
which will, at least partially, alleviate some of the above-mentioned problems.
SUMMARY OF THE INVENTION
[0009] In accordance with this invention there is provided a refrigeration transport container
having doors at one end with a refrigeration unit behind a panel at the opposite end,
and wherein the refrigeration unit has a cold air outlet adjacent the bottom of the
container and an air inlet adjacent the top thereof, characterised in that the air
outlet is configured to discharge air into the container substantially above floor
level and wherein the air inlet draws air through a passage which opens into the container
near the doors.
[0010] Further features of the invention provide for a barrier to extend upwardly from the
floor across the width of the container adjacent the outlet and shaped to direct air
upwardly and to prevent movement of pallets on the floor towards the outlet; for the
height of the barrier to be substantially the height of a pallet; for elongate spaced
apart stops to be provided on the panel extending generally upwardly; for the stops
to extend partway between the air inlet and air outlet; and for a plate to extend
across the upper end of the stops between the sides of the container.
[0011] Still further features of the invention provide for the passage to extend along the
top of the container from the air inlet to near the doors; and for the passage to
extend the width of the container.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] One embodiment of the invention will be described, by way of example only, with reference
to the drawings in which:
- Figure 1
- is part sectional perspective view of a refrigeration container;
- Figure 2
- is a sectional side elevation of the refrigeration container in Figure 1; and,
- Figure 3
- is a sectional plain view of the refrigeration container in Figure 1.
DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS
[0013] A refrigeration transport container (1), in this embodiment a shipping container,
is shown in Figures 1 to 3 and includes a refrigeration unit (3) located at one end
(5) behind a panel (7) opposite the doors (9). The panel (7) extends parallel to the
end (5) between the sides (11) of the container (1) and is spaced apart from the top
(13) and bottom (15) thereof to provide elongate openings (17, 19) which act as an
air inlet and an air outlet respectively. A T-bar floor (21) is provided on the bottom
(15) of the container and extends from the doors (9) to adjacent the air outlet (19).
[0014] The container described thus far is of conventional configuration.
[0015] In accordance with the invention a barrier (25) is provided which extends between
the sides (11) adjacent the air outlet (19). The barrier (25) extends from the bottom
(15) of the container over the end of the T-bar floor (21) to the height of a standard
pallet (27) (shown in broken lines in Figure 2) above the T-bar floor (21).
[0016] A plurality of elongate stops (29), made in this embodiment from lengths of rectangular
tubing, are secured to the panel (7) spaced apart from each other and extending generally
upwardly. A plate (30) having the same thickness as the tubes extends across the upper
ends of the stops (29) between the sides (11) of the container.
[0017] The barrier (25) and stops (29) extend the same distance into the container from
the panel (7).
[0018] Furthermore, a passage (40) is provided internally along the top (13) of the container
by, in this embodiment, a metal sheet which extends between the sides (11) from the
air inlet (17) to near the doors (9). The passage (40) covers the air inlet (17) so
that air is drawn through the passage into the inlet.
[0019] In use, pallets (27) with produce (45) thereon are loaded into the container with
the front of the first pallet abutting the barrier (25) and that of the produce abutting
the stops (29). With the refrigeration unit (3) operational, air in the container
is drawn through the open end of the passage (40), cooled and forced into the container
once more through the outlet (19). The barrier (25) prevents the cooled air from flowing
either along the T-bar floor (21) or through the aligned openings of the pallets (27).
Instead, the cooled air is directed by the barrier (25) upwardly between the stops
(29). The plate (30) prevents continued upward flow of the cooled air and which is
thus forced to flow through the produce (45) until it is able to escape and return
through the passage (40).
[0020] The configuration of the container is highly effective in that the cooled air is
immediately used to cool the produce and does not have an opportunity to short-circuit
along the floor, sides or top of the container. Furthermore, the approximately 6m
2 area of the panel (7) over which air is forced into the container is much smaller
than the approximately 26m
2 area of the floor and the air velocity is consequently much higher, again providing
more efficient heat transfer. Still further, as the air is forced through the produce
there is little opportunity for dead spots to form and homogenous cooling is thus
achieved.
[0021] It is calculated that the high degree of homogenous cooling achieved by the configuration
of the container of the invention will result in a smaller temperature differential
across the refrigeration unit as compared to conventional refrigerated containers
and this has the result that the refrigeration unit will operate more effectively
and thus use less energy.
[0022] It is further envisaged that the elimination of hotspots and the reduction of the
temperature differential across the refrigeration unit will result in an improved
relative humidity of close to 95%. This in turn will enhance the quality of the produce
and discourage deterioration thereof.
[0023] As the container of the present invention does not require airflow along the floor
or bottom of the container, and in fact prevents such flow, it is not necessary for
the container to be provided with a T-bar floor. The T-bar floor could thus be eliminated,
at least in part, and this can result in a saving of up to 750 kg in weight and an
associated saving of the cost of materials and manufacturing.
[0024] Existing refrigerated containers can easily be modified to incorporate the features
of the invention, or refrigerated containers can be built to incorporate these features.
[0025] It will be appreciated that many other embodiments of a refrigerated container exist
which fall within the scope of the invention particularly as regards the configuration
thereof. For example, the plate across the top of the stops can be bent to extend
downwards towards the floor to aid mixing of the air. Also, any suitable stops can
be used, including, for example, rubber extrusions. Furthermore, the inlet passage
could have any suitable configuration and could, for example, include a number of
tubes which could run between the inner and outer sides of the container.
1. A refrigeration transport container (1) having doors (9) at one end with a refrigeration
unit (3) behind a panel (7) at the opposite end, and wherein the refrigeration (3)
unit has a cold air outlet (19) adjacent the bottom (15) of the container (1) and
an air inlet (17) adjacent the top (13) thereof, and wherein a barrier (25) extends
upwardly from a floor (21) of the container provided on the bottom (15) thereof across
the width of the container (1) adjacent the outlet (19) and is shaped to direct air
from the outlet (19) upwardly such that air is discharged into the container (1) substantially
above floor level, and the barrier further shaped to prevent movement of pallets on
the floor (21) towards the outlet (19) and wherein the air inlet (17) draws air through
a passage (40) which opens into the container (1) near the doors (9).
2. A refrigeration transport container (1) as claimed in claim 1 wherein elongate spaced
apart stops (29) are provided on the panel (7) extending in a generally upward direction.
3. A refrigeration transport container (1) as claimed in claim 1 or 2 wherein the height
of the barrier (25) is substantially the height of a pallet.
4. A refrigeration transport container (1) as claimed in claim 2 wherein the stops (29)
extend partway between the air inlet (17) and air outlet (19).
5. A refrigeration transport container (1) as claimed in claim 4 wherein a plate (30)
extends across the upper end of the stops (29) between the sides of the container
(1).
6. A refrigeration transport container (1) as claimed in any one of the preceding claims
wherein the passage (40) extends along the top of the container (1) from the air inlet
(17) to near the doors (9).
7. A refrigeration transport container (1) as claimed in any one of the preceding claims
wherein the passage (40) extends the width of the container (1).
1. Kühltransportcontainer (1) mit Türen (9) an einem Ende, mit einer Kühleinheit (3)
hinter einer Platte (7) am gegenüberliegenden Ende und wobei die Kühleinheit (3) einen
Kaltluftauslass (19) nahe dem Boden (15) des Containers (1) und einen Lufteinlass
(17) nahe der Oberseite (13) davon aufweist und wobei eine Barriere (25) sich aufwärts
von einem Boden (21) des Containers erstreckt, welche auf dem Boden (15) davon über
die Breite des Containers (1) nahe dem Auslass (19) vorgesehen und so geformt ist,
um Luft aus dem Auslass (19) nach oben zu lenken, so dass Luft in den Container (1)
im Wesentlichen über dem Bodenniveau eingespeist wird, und wobei die Barriere des
Weiteren geformt ist, um die Bewegung von Paletten auf dem Boden (21) zum Auslass
(19) hin zu verhindern und wobei der Lufteinlass (17) Luft durch einen Durchlasskanal
(40) zieht, welcher sich in den Container (1) in der Nähe der Türen (9) öffnet.
2. Kühltransportcontainer (1) nach Anspruch 1, wobei längliche, beabstandete Anschläge
(29) auf der Platte (7) vorgesehen sind, welche sich in einer allgemein nach oben
gerichteten Richtung erstrecken.
3. Kühltransportcontainer (1) nach Anspruch 1 oder 2, wobei die Höhe der Barriere (25)
im Wesentlichen die Höhe einer Palette beträgt.
4. Kühltransportcontainer (1) nach Anspruch 2, wobei die Anschläge (29) sich teilweise
zwischen dem Lufteinlass (17) und dem Luftauslass (19) erstrecken.
5. Kühltransportcontainer (1) nach Anspruch 4, wobei eine Platte (30) sich über das obere
Ende der Anschläge (29) zwischen den Seiten des Containers (1) erstreckt.
6. Kühltransportcontainer (1) nach einem der vorhergehenden Ansprüche, wobei der Durchlasskanal
(40) sich entlang der Oberseite des Containers (1) vom Lufteinlass (17) bis in die
Nähe der Türen (9) erstreckt.
7. Kühltransportcontainer (1) nach einem beliebigen der vorhergehenden Ansprüche, wobei
der Durchlasskanal (40) sich über die Breite des Containers (1) erstreckt.
1. Conteneur de transport de réfrigération (1) présentant des portes (9) au niveau d'une
extrémité avec une unité de réfrigération (3) derrière un panneau (7) au niveau de
l'extrémité opposée, et dans lequel l'unité de réfrigération (3) présente une sortie
d'air froid (19) adjacente au bas (15) du conteneur (1) et une entrée d'air (17) adjacente
au bas (13) de celui-ci, et dans lequel une barrière (25) s'étend vers le haut depuis
un plancher (21) du conteneur prévu sur le bas(15) de celui-ci sur la largeur du conteneur
(1) adjacent à la sortie (19) et est formée pour diriger de l'air de la sortie (19)
vers le haut de sorte que de l'air soit évacué dans le conteneur (1) sensiblement
au-dessus du niveau du plancher, et la barrière est en outre formée pour empêcher
le mouvement de palettes sur le plancher (21) vers la sortie (19) et dans lequel l'entrée
d'air (17) aspire de l'air par un passage (40) qui s'ouvre dans le conteneur (1) à
proximité des portes (9).
2. Conteneur de transport de réfrigération (1) selon la revendication 1, dans lequel
des butées espacées allongées (29) sont prévues sur le panneau (7) s'étendant dans
une direction généralement vers le haut.
3. Conteneur de transport de réfrigération (1) selon la revendication 1 ou 2, dans lequel
la hauteur de la barrière (25) est sensiblement la hauteur d'une palette.
4. Conteneur de transport de réfrigération (1) selon la revendication 2, dans lequel
les butées (29) s'étendent à mi-chemin entre l'entrée d'air (17) et la sortie d'air
(19).
5. Conteneur de transport de réfrigération (1) selon la revendication 4, dans lequel
une plaque (30) s'étend sur l'extrémité supérieure des butées (29) entre les côtés
du conteneur (1).
6. Conteneur de transport de réfrigération (1) selon l'une quelconque des revendications
précédentes, dans lequel le passage (40) s'étend le long du haut du conteneur (1)
de l'entrée d'air (17) jusqu'à proximité des portes (9).
7. Conteneur de transport de réfrigération (1) selon l'une quelconque des revendications
précédentes, dans lequel le passage (40) étend la largeur du conteneur (1).