U.S. patent application number 13/128848 was filed with the patent office on 2011-12-01 for thermally insulated reusable transportation container.
This patent application is currently assigned to TOWER COLD CHAIN SOLUTIONS. Invention is credited to Christopher Robert Krzak, James Vann.
Application Number | 20110290792 13/128848 |
Document ID | / |
Family ID | 40194655 |
Filed Date | 2011-12-01 |
United States Patent
Application |
20110290792 |
Kind Code |
A1 |
Krzak; Christopher Robert ;
et al. |
December 1, 2011 |
THERMALLY INSULATED REUSABLE TRANSPORTATION CONTAINER
Abstract
A reusable transportation container for transporting temperature
sensitive goods. The transportation container (20) includes: a
substantially rigid body (32,34) having a thermally insulated
storage volume (36); means (22) for accessing the thermally
insulated storage volume (36); a set of PCM units (37) that can be
inserted into and removed from the thermally insulated storage
volume, wherein each of the PCM units (39, 41, 43) includes a
sealable substantially rigid container (35) for storing phase
change material therein, said set of PCM units (37) being
constructed and arranged to fit together to form a hollow structure
that provides a substantially enclosed payload volume (22) for
receiving the temperature sensitive goods, wherein the set of PCM
units (37) is arranged to maintain the goods stored in the payload
volume (36) within a selected temperature range when in use; and
wherein at least some of the PCM units (39,41,43) include support
formations (47) that are arranged to interact with an adjacent PCM
unit (39, 41, 43) to prevent the hollow structure from collapsing
inwards during use.
Inventors: |
Krzak; Christopher Robert;
(Berkshire, GB) ; Vann; James; (Buckinghamshire,
GB) |
Assignee: |
TOWER COLD CHAIN SOLUTIONS
|
Family ID: |
40194655 |
Appl. No.: |
13/128848 |
Filed: |
November 13, 2009 |
PCT Filed: |
November 13, 2009 |
PCT NO: |
PCT/GB09/02652 |
371 Date: |
August 19, 2011 |
Current U.S.
Class: |
220/1.5 ;
53/440 |
Current CPC
Class: |
F25D 2303/082 20130101;
F25D 2303/0822 20130101; F25D 2700/12 20130101; F25D 2303/0844
20130101; F25D 2303/08222 20130101; F25D 2303/0843 20130101; F25D
2700/14 20130101; F25D 3/08 20130101; B65D 81/3823 20130101; B65D
81/3816 20130101; F25D 2303/085 20130101; F25D 2303/08221 20130101;
F25D 2303/0845 20130101; Y02W 30/80 20150501 |
Class at
Publication: |
220/1.5 ;
53/440 |
International
Class: |
B65D 81/38 20060101
B65D081/38; B65B 63/08 20060101 B65B063/08; B65D 88/12 20060101
B65D088/12 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 14, 2008 |
GB |
0820876.1 |
Claims
1. A reusable transportation container for transporting temperature
sensitive goods, including: a substantially rigid body having a
thermally insulated storage volume; means for accessing the
thermally insulated storage volume; a set of phase change materials
(PCM) units that can be inserted into and removed from the
thermally insulated storage volume, wherein each of the PCM units
includes a sealable substantially rigid container for storing phase
change material therein, wherein said set of PCM units fit together
to form a hollow structure that provides a substantially enclosed
payload volume for receiving the temperature sensitive goods,
wherein the set of PCM units maintains the goods stored in the
payload volume within a selected temperature range; and wherein at
least some of the PCM units include support formations that
interact with an adjacent PCM unit to prevent the hollow structure
from collapsing inwards.
2. A container according to claim 1, wherein at least one of the
support formations is formed integrally with one of the PCM
units.
3. A container according to claim 2, wherein the support formations
include at least one of a protrusion, ridge, rib, stepped surface
or recess.
4. A container according to claim 1, wherein at least one of the
PCM units in the set includes a complementary formation to the
support formation that engages with the support formation.
5. A container according to claim 4, wherein at least one of the
PCM units in the set includes support formations and complementary
formations.
6. A container according to claim 1, wherein at least some of the
PCM units in the set include locating formations on one surface and
complementary locating recesses on an opposite surface.
7. A container according to claim 1, wherein the PCM units are
arranged to interlock.
8. A container according to claim 1, wherein the hollow structure
includes a base, at least one side wall, and at least one upper
member.
9. A container according to claim 8, wherein the base includes
support formations that restrict relative movement between the base
and each of the side walls.
10. A container according to claim 8, wherein the upper member
includes support formations to restrict relative movement between
the upper member and each of the side walls.
11. A container according to claim 8, wherein at least one of the
side walls includes at least one support formation that restricts
relative movement between the side wall including the support
formation and at least one other adjacent side wall.
12. A container according to claim 1, wherein the PCM units are
arranged in layers.
13. A container according to claim 1, wherein the set of PCM units
includes a first PCM unit having a first PCM that changes phase at
a first temperature and a second PCM unit having a second PCM that
changes phase at a second temperature, wherein the first and second
temperatures are different.
14. A container according to claim 13, wherein the first PCM
changes phase at a temperature in the range of -20.degree. C. to
+5.degree. C., and the second PCM changes phase at a temperature in
the range of +5.degree. C. to +20.degree. C.
15. A container according to claim 13, wherein the first PCM mostly
comprises of water and the second PCM mostly comprises of a
wax.
16. A container according to claim 13, wherein the second PCM
changes phase at a higher temperature than the first PCM, and the
second PCM unit is positioned closer to the payload than the first
PCM unit.
17. A container according to claim 16, wherein the set of PCM units
includes a plurality of first PCM units and a plurality of second
PCM units, wherein the the payload volume is substantially defined
by the plurality of second PCM units, and the plurality of first
PCM units are mounted on, or to, the second PCM units such that
they are located outside of the payload volume.
18. A container according to claim 1, wherein the phase change
material changes from a solid state to a liquid state at a
temperature in a range selected from the group consisting of
+2.degree. C. to +8.degree. C., -25.degree. C. to -15.degree. C.
and +15.degree. C. to +25.degree. C.
19. A container according to claim 1, wherein at least one of the
PCM units includes stiffening formations to stiffen its
structure.
20. A container according to claim 1, wherein at least one of PCM
units includes a lifting formation.
21. A container according to claim 1, wherein the means for
accessing the thermally insulated storage volume includes a
sealable lid.
22. A container according to claim 1, further including means for
preventing the hollow structure from collapsing outwards.
23. A container according to claim 22, wherein the set of PCM units
ensures a tight fit between the hollow structure and the thermal
insulation.
24. A container according to claim 1, further including an external
temperature sensor for measuring the ambient temperature outside of
the container.
25. A container according to claim 1, further including an internal
temperature sensor for measuring the temperature in the payload
volume.
26. A container according to claim 1, further including a recording
device for recording the temperature in the payload volume and/or
the ambient temperature.
27. A method for transporting temperature sensitive goods,
including: providing a reusable container having a substantially
rigid body, a thermally insulated storage volume, and means for
accessing the thermally insulated storage volume; providing a set
of PCM units, wherein each of the PCM units includes a sealable
substantially rigid container for storing phase change material
therein and at least some of the PCM units include support
formations; placing the set of PCM units into the thermally
insulated storage volume, forming a hollow structure from the set
of PCM units that provides a substantially enclosed payload volume
for receiving the temperature sensitive goods, including arranging
the PCM units such that the support formations engage with an
adjacent PCM unit, the engaging interaction between the support
formation and the adjacent PCM unit thereby preventing the hollow
structure from collapsing inwards during transportation.
28. A method according to claim 27, wherein the hollow structure
includes a base, at least one side wall, and at least one upper
member.
29. A method according to claim 28, wherein the support formations
on the base restrict relative movement between the base and the or
each side wall.
30. A method according to claim 28, wherein the support formations
on the upper member restrict relative movement between the upper
member and the or each side wall.
31. A method according to claim 28, wherein at least one side wall
having at least one support formation is provided, wherein the
support formation interacts with an adjacent side wall thereby
restricting relative movement between the side wall including the
support formation and the adjacent side wall.
32. A method according to claim 27, wherein the structure is
dismantled after use.
Description
[0001] The present invention relates to a thermally insulated
reusable transportation container for transporting temperature
sensitive items, and a method for transporting temperature
sensitive goods.
[0002] Thermally insulated containers are used to transport items
that are sensitive to temperature and must therefore be maintained
within predetermined temperature ranges, such as +2.degree. C. to
+8.degree. C. and +15.degree. C. to +25.degree. C., or close to a
particular temperature such as -20.degree. C. Such items include
goods such as vaccines and drugs, biological samples, tissue
cultures, chilled and frozen foods and many other products, some of
which have extremely high financial value and are very sensitive to
temperature changes. It is essential that such products are
maintained within the appropriate temperature ranges during
transportation.
[0003] Such goods are normally transported in cardboard or plastic
containers packed with insulative materials, such as polystyrene,
and gel bags containing phase change materials (hereafter referred
to as PCMs) that have been cooled or heated to a predetermined
temperature to provide additional heating or cooling as required.
Heat energy flows into or out of the container, according to the
difference between the ambient temperature and the internal
temperature of the container. The temporal ambient temperature
profile that will be experienced by the container cannot be
predicted a priori, since containers may be moved from relatively
cold countries to relatively hot countries and may be left standing
for a significant period of time.
[0004] If the container is exposed to excessively high or low
temperatures for extended periods, the internal temperature may go
outside the required range, causing damage to the contents. The
requirement to open a container on its journey increases the risk
of payload theft. In current containers, the number and type of PCM
packs employed is calculated according to the anticipated delivery
time and the ambient temperature ranges likely to be experienced
during transportation. However, as delivery can take longer than
anticipated and the ambient temperatures may be much higher or
lower than expected, the payload temperature may go outside the
required range. During transportation, shocks, collisions or
vibrations can cause the goods to move within the container,
particularly those located at the side walls; these might then fall
to a lower part of the container, increasing the risk of being
heated/cooled to a temperature outside the predetermined safe
range.
[0005] Anecdotal evidence suggests that large numbers of
pharmaceutical/medicinal products are rendered unusable each year
because they are not transported in the correct temperature range.
For the pharmaceutical industry this presents significant waste,
and hence cost, and there is an environmental impact as new goods
will have to be produced and transported. For recipients of the
goods there are significant health risks, because it may not be
evident at the endpoint of the transport that the product has been
rendered unsafe. For products such as vaccines this may result in
loss of efficacy.
[0006] Another problem with many existing insulated containers is
that they are not reusable. This is inconsistent with modern
environmental protection policies and can lead to major storage and
waste disposal problems. Some reusable containers do exist but they
have only had limited success because the refrigeration systems
used are not designed to last for long periods of time.
[0007] Certain vaccines degrade at a rate that depends on ambient
temperature. As the loss of efficacy increases with temperature, it
is desirable to maintain the temperature within the acceptable
range (e.g. 2.degree. C. to 8.degree. C.).
[0008] It is an object of the present invention to provide an
insulated container that mitigates at least one of the
aforementioned disadvantages, or at least provides an alternative
configuration.
[0009] According to one aspect of the invention there is provided a
reusable transportation container for transporting temperature
sensitive goods, said container including: a substantially rigid
body having a thermally insulated storage volume; means for
accessing the thermally insulated storage volume; a set of PCM
units that can be inserted into and removed from the thermally
insulated storage volume, wherein each of the PCM units includes a
sealable substantially rigid container for storing phase change
material therein, said set of PCM units being constructed and
arranged to fit together to form a hollow structure that provides a
substantially enclosed payload volume for receiving the temperature
sensitive goods, wherein the set of PCM units is arranged to
maintain the goods stored in the payload volume within a selected
temperature range when in use; and wherein at least some of the PCM
units include support formations that are arranged to interact with
an adjacent PCM unit to prevent the hollow structure from
collapsing inwards during use.
[0010] The invention prevents the goods from being damaged during
transit and enables the payload temperature to be more predictable
and better controlled as the arrangement of the PCM units is
predetermined, and typically regular. Thus it is less likely that
any part of the payload will move to a temperature outside of the
selected range during transit. The arrangement of the PCM units in
the form of a hollow structure maintains temperature equilibriation
of the storage volume by air conduction.
[0011] The PCM units are arranged to be thermally conditioned prior
to use such that the material within is uniformly in one physical
state. During transit the PCM units absorb heat energy from, or
supply heat energy to, their surroundings thereby causing the PCM
within to change physical state over a period of time. The rigid
arrangement of the PCM units also maintains temperature
equilibriation of the storage volume by air conduction.
[0012] Typically a PCM is selected to change physical state at a
temperature in one of the following ranges: +2.degree. C. to
+8.degree. C.; -25.degree. C. to -15.degree. C.; +15 to +25.degree.
C. When it is required to maintain the temperature of the goods at
around -20.degree. C., preferably the PCM is a salt solution such
as silver nitrate eutectic salt solution chosen to give a melting
point of -20.degree. C. Preferably the phase change material is
selected to have at least one of the following thermal properties:
a high latent heat energy of fusion per unit volume, a high
specific heat energy capacity, low density, high thermal
conductivity, small volume changes on phase transformation and low
vapour pressure at operating temperatures.
[0013] Since the PCM units store the phase change material, in use,
and the hollow container is substantially rigid, this ensures that
the overall body of the PCM units is substantially rigid even when
the PCM is in a liquid or solid state. The hollow container is
preferably made from a polymer such as polyethylene.
[0014] Advantageously at least one of the support formations is
formed integrally with one of the PCM units. Advantageously each
PCM unit can include a plurality support formations. In preferred
embodiments a plurality of the PCM units in the set include at
least one of the support formations and preferably a plurality of
the support formations. Preferably the or each support formation is
in the form of a raised formation such as a ridge, rib, protrusion,
lug, or some other similar formation that is upstanding from one of
the surfaces of the PCM unit.
[0015] Typically the set of PCM units is arranged such that the
support formations are located within the hollow structure when
fitted together.
[0016] When the PCM units are fitted together to form the hollow
structure, the or each support formation interacts with at least
one adjacent PCM unit to restrict relative movement between the PCM
unit including the support formation and the adjacent PCM unit in
at least one direction.
[0017] Advantageously at least one of the PCM units can include a
complementary formation to the support formation that is arranged
to engage with the support formation to restrict relative movement
between the PCM unit including the support formation and the PCM
unit including the complementary formation. The complementary
formation can include a profiled surface of the PCM unit, or a
recess formed in one of the surfaces of the PCM unit, that is
arranged to engage with, or receive, the ridge, rib, protrusion,
lug or the other similar formation. For example, the side faces of
at least some of the PCM units can be profiled, such as chamfered
at approximately 45.degree., such that they can engage with
triangular sectioned support formations in adjacent PCM units.
Advantageously a plurality of PCM units in the set can each include
a plurality support formations and a plurality of PCM units in the
set each include a plurality of complementary formations.
[0018] Advantageously at least one of the PCM units in the set can
include support formations and complementary formations.
Advantageously a plurality of the PCM units in the set includes
support formations and complementary formations, and preferably all
of the PCM units are so arranged.
[0019] The PCM units can be arranged such that the support
formations and the complementary formations interlock. This
prevents relative movement between interlocked PCM units.
[0020] Advantageously at least some of the PCM units in the set can
include locating formations on one surface and complementary
locating recesses on an opposite surface. This allows the PCM units
to be securely attached to each other, for example in a horizontal
or vertical stacking arrangement. For example, the locating
formations can be in the form of raised T-shaped or cross-shaped
formations and the recesses are arranged complementary thereto.
Advantageously the locating formations can be located on the same
surface as the support formations. In this instance the surface
including the complementary locating recesses also includes
recesses that are arranged to accommodate the support
formations.
[0021] In preferred embodiments, the hollow structure includes a
base, at least one side wall, and at least one upper member. For
example, the base may include support formations that are arranged
to restrict relative movement between the base and each of the side
walls in at least one direction for each side wall. Preferably the
hollow structure includes four side walls and the base includes
four support formations arranged to engage with complementary
formations included in each of the side walls.
[0022] The upper member may include support formations to restrict
relative movement between the upper member and each of the side
walls in at least one direction for each side wall. For hollow
structures including four side walls the upper member preferably
includes four support formations arranged to engage with
complementary formations included in each of the side walls.
[0023] At least some of the side walls may include at least one
support formation arranged to restrict relative movement in at
least one direction between the side wall including the support
formation and at least one other adjacent side wall. Advantageously
each side wall can include at least one support formation arranged
to restrict relative movement between the side wall and the base in
at least one direction; and/or at least one support formation
arranged to restrict relative movement between the side wall and
the upper member in at least one direction.
[0024] Advantageously the hollow structure can be substantially
cuboid and the set of heat energy reservoirs includes at least six
PCM units to form the cuboid structure. Depending on the size of
the container, the base, each side wall and the upper member may
each comprise a plurality of PCM units, for example mounted side by
side. Typically, the set of PCM units contains between 3 and 20 PCM
units and more preferably between 6 and 16 PCM units, however any
suitable number can be used. A set of three PCM units can be in the
form of a cylindrical structure, for example one curved side wall,
a base and a lid. In most applications the hollow structure will be
a cube, or is cuboid, and therefore includes at least six PCM
units. It will be appreciated by the skilled person that other
shapes can be used for the hollow structure and the number and
shape of the PCM units is determined accordingly.
[0025] Further, depending on the heating/cooling capacity required,
any of the base, each side wall, and the upper member may include a
plurality of layers of PCM units, for example two or more PCM units
stacked either vertically or horizontally.
[0026] The container can be arranged to include at least one PCM
unit that will freeze during use, thus liberating heat energy, and
at least one PCM unit that melts during use, thus absorbing heat
energy. The set of PCM units can include a first PCM unit having a
first PCM arranged to change phase at a first temperature and a
second PCM unit having a second PCM arranged to change phase at a
second temperature, wherein the first and second temperatures are
different.
[0027] For example, when it is required to maintain the temperature
of the goods in the range +2.degree. C. to +8.degree. C., the first
PCM is selected to change phase at a temperature in the range
-20.degree. C. to +5.degree. C. and the second PCM is selected to
change phase at a temperature in the range +5.degree. C. to
+20.degree. C. Preferably at least one of the PCM units is
water-based with a melting point around 0.degree. C., and may
include additives such as acticides and nucleating agents; and at
least one of the PCMs can comprise a paraffin wax which has a
melting point of around +5.degree. C. Thus the second PCM changes
phase at a higher temperature than the first PCM, and the
arrangement is such that the second PCM unit is positioned closer
to the payload than the first PCM unit. The advantage of this is
that the first PCM unit acts as a heat sink for the second PCM
unit.
[0028] In most practical applications the set of PCM units can
include a plurality of first PCM units and a plurality of second
PCM units and the structure is arranged such that payload volume is
substantially defined by the plurality of second PCM units, and the
plurality of first PCM units are mounted on, or to, the second PCM
units such that they are located outside of the payload volume.
This provides a very efficient arrangement and helps to ensure that
the goods are not heated or cooled to a temperature outside of the
required range. Any practicable number of units can be stacked or
layered together.
[0029] Advantageously the set of PCM units are releasably engaged
with each other such that the hollow structure can be disassembled
to enable the PCM units to be more easily thermally
conditioned.
[0030] Advantageously the set of PCM units can be constructed and
arranged such that there is a tight fit between the hollow
structure and the thermal insulation. This enables the thermal
insulation to provide support for the hollow structure to ensure
that the PCM units do not collapse outwards during transit.
[0031] Advantageously at least one of the PCM units can include
stiffening formations to stiffen its structure. Preferably the
stiffening formations include through holes or a kiss-off
arrangement.
[0032] Advantageously at least one of PCM units can include a
lifting formation. The lifting formation can include a through hole
that is sufficiently large for a user of the device to grip the
heat reservoir by hand.
[0033] Advantageously the container can include an external
temperature sensor device for measuring the ambient temperature
and/or an internal temperature sensor device for measuring the
payload temperature. Advantageously the container can include an
automated data logger for recording the payload temperature and/or
the ambient temperature, for example as part of its permanent
structure. Advantageously the container can include as part of its
permanent structure other bespoke hardware and software which,
using information recorded by the data logger, can calculate and
display information pertinent to the remaining lifetime of the
products which make up the payload.
[0034] Advantageously the means for accessing the thermally
insulated storage volume includes a sealable lid. Advantageously,
the container can include a main body and the lid can be hinged to
the main body.
[0035] Preferably the outer shell is made from either a polymer or
reinforced glass fibre. The container can be substantially
transparent to x-rays in at least one direction.
[0036] Advantageously the container can include a switch device or
sensor that is arranged to detect the opening and/or closing of the
container. The switch device or sensor is preferably connected to
the data logger, which is arranged to record the opening and/or
closing events. This enables unauthorised access of the container
to be detected.
[0037] According to another aspect of the invention there is
provided a method for transporting temperature sensitive goods,
including: providing a reusable container having a substantially
rigid body, a thermally insulated storage volume, and means for
accessing the thermally insulated storage volume; providing a set
of PCM units, wherein each of the PCM units includes a sealable
substantially rigid container for storing phase change material
therein and at least some of the PCM units include support
formations; placing the set of PCM units into the thermally
insulated storage volume, forming a hollow structure from the set
of PCM units that provides a substantially enclosed payload volume
for receiving the temperature sensitive goods, including arranging
the PCM units such that the support formations engage with an
adjacent PCM unit, the engaging interaction between the support
formation and the adjacent PCM unit thereby preventing the hollow
structure from collapsing inwards during transportation.
[0038] Advantageously the method can include forming the hollow
structure to include a base, at least one side wall, and at least
one upper member.
[0039] Advantageously the method can include the support formations
on the base restricting relative movement between the base and the
or each side wall.
[0040] Advantageously the method can include the support formations
on the upper member restricting relative movement between the upper
member and the or each side wall.
[0041] Advantageously the method can include providing at least one
side wall having at least one support formation, the support
formation interacting with an adjacent side wall thereby
restricting relative movement between the side wall including the
support formation and the adjacent side wall.
[0042] Advantageously the method can include dismantling the
structure after use.
[0043] According to another aspect of the invention there is
provided a reusable transportation container for transporting
temperature sensitive goods, said container including: a
substantially rigid body having a thermally insulated storage
volume; means for accessing the thermally insulated storage volume;
a set of PCM units that can be inserted into and removed from the
thermally insulated storage volume, said set of PCM units including
a first PCM unit having a first PCM arranged to change phase at a
first temperature and a first substantially rigid body for storing
the first PCM, and a second PCM unit having a second PCM arranged
to change phase at a second temperature and a second substantially
rigid body for storing the second. PCM, wherein the first and
second temperatures are different; a first sensor device arranged
to measure the temperature inside the storage volume; a second
sensor device arranged to measure the ambient temperature outside
of the container; and a data logging device for recording
temperature data measured by the first and second sensor
devices.
[0044] Advantageously the rigidity of the PCMs facilitates
temperature equilibriation of the storage volume by air
conduction.
[0045] Advantageously the set of PCM units can be constructed and
arranged to fit together to form a hollow structure that provides a
substantially enclosed payload volume for receiving the temperature
sensitive goods, wherein the set of PCM units is arranged to
maintain the goods stored in the payload volume within a selected
temperature range when in use; and the container includes support
means arranged to maintain the relative positions of the PCM units
during transit. The arrangement of the PCM units in the form of a
hollow structure also facilitates temperature equilibriation of the
storage volume by air conduction.
[0046] Advantageously the PCM units can be arranged in any
configuration described herein and the container can include any of
the other features of the first aspect of the invention.
[0047] Embodiments of the invention will now be described by way of
example only with reference to the accompanying drawings, in
which:
[0048] FIG. 1 is an isometric view of an insulated container
according to a first embodiment of the invention;
[0049] FIG. 2 is an isometric view of a PCM panel (hereinafter
referred to as a PCMP);
[0050] FIG. 3 is an end view of the PCMP of FIG. 2;
[0051] FIG. 4 is a plan view of the PCMP of FIG. 2;
[0052] FIG. 5 is a side view of the PCMP of FIG. 2;
[0053] FIG. 6 is an isometric view of an insulated container
according to a second embodiment of the invention; and
[0054] FIGS. 7 to 10 are views of alternatively configured PCMPs
for use in the insulated container of FIG. 1.
[0055] An insulated container according to a first embodiment of
the invention is shown in FIGS. 1 to 5. The insulated container 20
is in the form of a box having a pivotable lid 22 and a set of feet
24. Two clips 26 are provided for securing the lid 22 in place.
[0056] The insulated container 20 is designed specifically for use
in transporting goods that must be maintained at a temperature of
between +2.degree. C. and +8.degree. C., such as, for example,
vaccines and transplant organs. Insulated containers for different
temperatures will be generally similar in construction, but may be
modified as described in more detail below to maintain the required
temperatures. For example, for some applications the internal
temperature must be maintained in the range +15.degree. C. to
+25.degree. C. whereas for other applications, the internal
temperature must be maintained in the range -25.degree. C. to
-15.degree. C.
[0057] The insulated container 20 consists of a casing 30 that
includes an outer shell 32 of, for example, glass reinforced
plastic (GRP), metal or a plastics material. The casing has an
inner liner 34 of insulating materials with a very low thermal
conductivity value, for example a foamed plastics material. The lid
22 includes a silicon seal which has a sealing fit with the body of
the box. The lid 22 has a similar construction to the body of the
container.
[0058] Inside the inner liner 34 there is provided a storage volume
36 that is arranged to receive a set 37 of PCMPs. The set 37
comprises sixteen PCMPs that are arranged to fit together to
provide a substantially enclosed payload volume with the requisite
cooling capability. Each PCMP comprises a hollow container 35 made
from a polymer such as polyethylene and is filled with a PCM. The
PCM used is dependent on the temperature characteristics that the
payload requires. The container 20 shown in FIG. 1 has a capacity
of around 400 L and is provided with three different types of PCMPs
in order to maintain the goods being transported at a temperature
of between +2.degree. C. and +8.degree. C.: six large PCMPs 39
containing a PCM that changes phase at around 0.degree. C.; four
large PCMPs 41 containing a PCM that changes phase at around
+5.degree. C.; and six small PCMPs 43 containing a PCM that changes
phase at around +5.degree. C. The PCM that changes phase at around
0.degree. C. comprises filtered water and two acticides: DB20,
which is fast acting, and MBS, which is slower acting. The PCM that
changes phase at around +5.degree. C. comprises a paraffin wax
(mostly n-tetradecane). In the Figures the large PCMPs 39,41 have a
capacity of around 14 litres and the small PCMPs 43 have a capacity
of around 12 litres. It will be apparent to the skilled person that
containers having different capacities can be used. Each PCMP is
filled via an opening in the container, which is then sealed with a
foil seal and covered with a protective polythene cap 44.
Alternatively, the cap 44 can be spun welded to the container body,
or can comprise a screw cap or bung.
[0059] The current capacities have been selected on the basis of
current health and safety lifting requirements and with
consideration for the size of refrigeration units available to
condition the PCMPs prior to use. If lifting equipment is
available, together with large refrigeration units, then larger
PCMPs can be used, which will reduce the number of PCMPs required
to provide a substantially enclosed payload.
[0060] Each large container 35 includes a hollow body that is
substantially cuboid having a length of 600 mm, width of 500 mm and
a depth of 50 mm, and thus the container is substantially planar in
that it has a large surface area when viewed in plan and a
relatively small depth. On one of the planar surfaces, hereinafter
referred to as the upper planar surface 45, there is provided a
series of raised support formations that includes four ridges 47,
at least two cross-shaped locating formations 49 and two T-shaped
locating formations 51. Each ridge 47 is arranged parallel to one
of the edges of the upper planar surface and extends along a
substantial part of the length/width of the planar surface. Each
ridge 47 is spaced from the edge of the upper planar surface such
that a border 53 extends around the ridges 47 on the upper planar
surface. Each ridge 47 has a triangular cross-section having
longitudinal faces that are inclined to the planar upper surface at
around 45 degrees. The end faces 55 are also inclined to the upper
planar surface.
[0061] The container includes side faces 61 that are chamfered 63
at 45 degrees. The chamfered surfaces 63 are arranged such that
that chamfered surfaces of a first PCMP can lie against the
inclined longitudinal faces of the ridges of a second PCMP in a
manner that fixes them in a perpendicular arrangement.
[0062] The other planar face, hereinafter referred to as the lower
planar face 57, includes a series of recesses 59 that are arranged
complementary to the raised formations (ridges, cross-shapes and
T-shapes) and are arranged to receive the raised formations on the
upper planar face 45 from a like container 35 when the like
container is stacked on top. Thus the raised formations and
recesses 59 provide locating formations to prevent lateral movement
between the PCMPs when they are stacked on top of each other.
[0063] Each container further includes a through hole 65 that is
arranged to receive a user's hand for the sake of ease of lifting
and four smaller through holes 67 that are arranged to stiffen the
container body.
[0064] Each small container is similar to the large container,
except that the upper and lower surfaces are substantially square
in plan (500 mm by 500 mm), and they only include two cross-shaped
formations 49 on its upper planar surface and two complementary
cross-shaped recesses on its lower planar surface 57.
[0065] An advantage of the invention is that for each of the
temperature ranges +2.degree. C. to +8.degree. C.; -25.degree. C.
to -15.degree. C.; +15.degree. C. to +25.degree. C. it is only
necessary to have one set of PCM panels (one different set for each
temperature range) for any destination, that is regardless as to
whether the container is being sent to a relatively hot country or
a relatively cold country. This is because of the thermal stability
achieved by the invention.
[0066] In use, prior to loading the insulated container 20, each of
the PCMPs 39,41,43 is conditioned by cooling (or heating) to
predetermined temperatures. The PCMPs containing a PCM that changes
phase at 0.degree. C. are cooled to a temperature of around
-20.degree. C. and the PCMPs containing a PCM that changes phase at
+5.degree. C. are cooled to a temperature of around +6.degree. C.
The PCMPs 39,41,43 are then loaded into the insulated container to
provide a substantially cuboid payload volume. Two of the large
0.degree. C. PCMPs 39 are placed towards the base of the insulated
container, side by side in a horizontal fashion, with their raised
formations facing upwards. One of the large +5.degree. C. PCMPs 41
is stacked on top of each of the 0.degree. C. PCMPs 39 horizontally
such that the raised formations of the large 0.degree. C. PCMPs 39
fit into the complementary recesses 59 in the large +5.degree. C.
PCMPs 41. The six small +5.degree. C. PCMPs 43 are then mounted on
top of the large +5.degree. C. PCMPs vertically such that they form
the sides of the cuboid payload volume, with their lower chamfered
surfaces 63 resting against the support ridges of the large
+5.degree. C. PCMPs their end faces located on the boarder area 53,
and their own ridges 47 facing inwards. This ensures the correct
location of the small PCMPs 43 and that they are arranged
substantially perpendicularly to the large +5.degree. C. PCMPs 41.
The interaction between the chamfered surfaces 63 of the small
PCMPs 43 and the ridges 47 of the large +5.degree. C. PCMPs 41, and
the chamfered surfaces 63 of the small PCMPs 43 and the ridges 47
of adjacent small side PCMPs 43, maintains their relative
positions.
[0067] At this stage the goods are loaded into the payload volume
and can be surrounded by a packing material such as bubble wrap to
ensure that the goods do not move during transit. If used, it is
preferable that the packing material has also been conditioned to
reduce its temperature prior to use.
[0068] Two of the large +5.degree. C. PCMPs 41 are then mounted on
top of the six small +5.degree. C. PCMPs 43 in a side by side
horizontal fashion to enclose the payload volume, with their raised
formations 47,49,51 facing downwards. Thus the ridges 47 on the
upper large +5.degree. C. PCMPs 41 engage with the upper chamfered
surfaces 153 of the small +5.degree. C. PCMPs 43, thereby
maintaining their relative positions. Two of the large 0.degree. C.
PCMPs 39 are then placed on top of each of the large +5.degree. C.
PCMPs 41. The large 0.degree. C. PCMPs 39 are stacked on top of the
large +5.degree. C. PCMPs 41 such that their raised formations
47,49,51 engage with the complementary recesses 59.
[0069] Since the large 0.degree. C. PCMPs 39 are cooler than the
+5.degree. C. PCMPs 41,43, heat energy flows from the +5.degree. C.
PCMPs 41,43 to the 0.degree. C. PCMPs 39, and thus the 0.degree. C.
PCMPs 39 act as heat sinks for absorbing heat energy from the
payload volume to reduce its temperature. The inventors have found
in testing that the insulated container 20 arranged with the PCMPs
39,41,43 as described above can maintain goods within the
+2.degree. C. and +8.degree. C. range for up to 260 hours (11
days). This has been found to hold true even in relatively hot
ambient conditions. This allows the insulated container 20 to be
transported very long distances without damage to the goods stored
therein, which addresses this key problematic requirement for the
pharmaceutical industry.
[0070] The insulated container includes an external temperature
sensor 52 mounted on the outside of the casing 30, and an internal
temperature sensor mounted inside the payload volume. These are
connected to a single or multi-channel data logger 56 that is
provided to maintain a record of the payload temperature during the
entire transit time. The temperature log may be kept in visual or
electronic form, and in the latter case facilities may be provided
for downloading the information to a computer. The data logger 56
can also be arranged to record events such as the insulated
container being opened or tampered with.
[0071] A second embodiment of the invention is shown in FIG. 6. The
second embodiment is similar to the first embodiment, except that
the volume of the insulated container 120 is smaller (approximately
70 L), and thus a smaller set 137 PCMPs is required. Also the
container 135 shapes are different though function in a similar
manner. The set 137 of PCMPs includes three large PCMPs 139
containing silver nitrate eutectic salt solution with a melting
point of around -20.degree. C. and seven small PCMPs 143 containing
the same PCM.
[0072] When thermally conditioning the PCMPs 139,143, they are
cooled to a temperature of around -23.degree. C. before being
inserted into the container. One of the small PCMPs 143 is located
in the base of the insulated container. The other six small PCMPs
143 are arranged vertically as shown in FIG. 6. The ridges 147 on
each of the small PCMPs 143 interact with chamfered surfaces 163 to
restrict relative movement between the PCMPs 143. After the goods
are loaded into the payload volume, the large PCMPs 139 are then
placed on top of the side walls 143 to enclose the goods.
[0073] The inventors have found in testing that the insulated
container 120 arranged with the PCMPs 139,143 as described above
can maintain goods at approximately -21.degree. C. for up to 260
hours (11 days) depending on the ambient temperature.
[0074] The larger PCMPs 143 include lifting handles 165, whereas
the smaller PCMPs 139 do not.
[0075] Both the large and small PCMPs 143,139 include through-holes
167 to increase the rigidity of the containers 135.
[0076] FIGS. 7 to 10 show third, fourth, fifth and sixth
alternative configurations for the PCMPs 235, 335, 435, 535. The
third PCMP 235 comprises a substantially cuboid hollow container,
wherein one of the larger rectangular surfaces when viewed in plan
is stepped such that a smaller substantially cuboid member
protrudes therefrom (see FIG. 7). A structure can be erected by
using a first PCMP 235 as a base and assembling at least four PCMPs
235 as side walls such that their protruding parts are located on
an upper surface 237 of the base. A further PCMP 235 can be placed
on top of the side walls to form a lid. The stepped parts 236
prevent the structure from collapsing inwards during use.
[0077] The fourth PCMP 335 is stepped similar to the third PCMP but
has different proportions. It is also envisaged that the
orientation of the PCMP 335 used as the base will be inverted when
compared with the base used for the third PCMP 235 when forming a
structure from a set of the PCMPs 335.
[0078] The fifth PCMP 435 is similar to the first PCMP 35 in that
it includes a substantially cuboid hollow container, which includes
chamfered surfaces 463 between side walls 461 and larger
substantially rectangular surfaces 445. Four ridges 447 having a
substantially triangular cross-section protrude from one of the
rectangular surfaces 445. The ridges 447 are joined end to end in a
substantially rectangular arrangement when viewed in plan (see FIG.
9). A set of the fifth PCMPs fits together in a similar manner to
the first set of PCMPs 35.
[0079] The sixth PCMP 535 includes a substantially cuboid hollow
container, having four ribs 547 protrude from one of the larger
rectangular surfaces 545. The ribs 547 have a substantially square
cross-section and are arranged end to end in a substantially
rectangular arrangement when viewed in plan (see FIG. 10). A set of
the sixth PCMP 535 fits together in a similar manner to a set of
the third PCMP 235.
[0080] Various modifications of the invention are possible that
fall within the scope of the current invention, some examples of
which are discussed below.
[0081] Different types of PCM may be used to meet required
temperature ranges. The invention is not to be considered as
limited to just the ranges mentioned in the examples.
[0082] Also, different numbers, sizes, geometrical shapes and
arrangements of PCMPs can be used to make up the substantially
enclosed payload volume. If two or more different PCMs are used,
different arrangements of the PCMPs can be made to obtain the
desired thermal requirements for the necessary period of time.
[0083] Different shape. PCMPs can be used to create alternative
hollow structures, for example a cylindrical hollow structure can
be created by having one or more PCMPs to make up the curved wall,
with short cylindrical PCMPs to provide end caps. The PCMPs can be
substantially square in plan to provide a substantially cube-like
structure. In the embodiments described above, the formations that
restrict relative movement between the PCMPs can be arranged to
interlock the units more firmly, for example by using a tongue and
groove arrangement, to provide an entirely self supporting
structure.
[0084] Different arrangements of protruding members and stepped
surfaces can be used to prevent a set of PCMPs from collapsing
inwards in use. The arrangements shown in FIGS. 7 to 10 are
arranged continuously. As an alternative, it is possible to have an
arrangement of discrete protruding members formed integrally with
the containers to interact with adjacent PCMPs to prevent the
structure from collapsing inwards.
[0085] In addition, or as an alternative, to the formations formed
integrally with the containers, separate support elements can be
provided for supporting the relative positions of the PCMPs.
[0086] The insulated container may be bar-coded or can include at
least one RFID tag to carry information such as the payload
carried, transit dates and any other information that may be
required. The insulated container may also be provided with visual
and/or audible warning devices, for example to warn that the
required temperature range has not been maintained.
* * * * *