U.S. patent application number 16/216429 was filed with the patent office on 2019-08-08 for conservation insulated container and/or transportation of perishable or heat sensitive products.
This patent application is currently assigned to L,Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude. The applicant listed for this patent is L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude. Invention is credited to Jean-Pierre BERNARD, Antony DALLAIS.
Application Number | 20190241348 16/216429 |
Document ID | / |
Family ID | 61028026 |
Filed Date | 2019-08-08 |
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United States Patent
Application |
20190241348 |
Kind Code |
A1 |
BERNARD; Jean-Pierre ; et
al. |
August 8, 2019 |
Conservation insulated container and/or transportation of
perishable or heat sensitive products
Abstract
An isothermal container for preserving and/or transporting
perishable or heat-sensitive products, includes a cryogenic
compartment for a mass of a cryogenic fluid, a product storage
compartment for the products to be preserved or transported, at
least one Seebeck module, and at least one fan positioned within
the product compartment to create forced convention therein that is
electrically powered by the Seebeck module, which generates a
voltage from the difference in temperature between the mass of
cryogen and the ambient air temperature of the product
compartment.
Inventors: |
BERNARD; Jean-Pierre;
(Guyancourt, FR) ; DALLAIS; Antony; (Janvry,
FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des
Procedes Georges Claude |
Paris |
|
FR |
|
|
Assignee: |
L,Air Liquide, Societe Anonyme pour
l'Etude et l'Exploitation des Procedes Georges Claude
Paris
FR
|
Family ID: |
61028026 |
Appl. No.: |
16/216429 |
Filed: |
December 11, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25D 3/12 20130101; B65D
81/38 20130101; H01L 35/00 20130101; F25D 2317/0681 20130101; F25D
3/125 20130101; F25D 17/06 20130101; F25D 2600/04 20130101; F25D
2331/804 20130101 |
International
Class: |
B65D 81/38 20060101
B65D081/38; F25D 3/12 20060101 F25D003/12; F25D 17/06 20060101
F25D017/06 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 12, 2017 |
FR |
FR 1761996 |
Claims
1-6. (canceled)
7. An isothermal container for preserving and/or transporting
perishable or heat-sensitive products, comprising a cryogenic
compartment adapted and configured to accept a mass of a cryogen
comprising lateral surfaces and a lower part that comprises a cold
plate; a product storage compartment adapted and configured to
store perishable or heat-sensitive products, wherein cooling of the
products takes place through contact between the cold plate and air
from the product compartment; at least one Seebeck module adapted
and configured to generate a voltage from the difference in
temperature between the mass of cryogen and an ambient temperature
of air in the product compartment through the Seebeck effect; and
at least one fan positioned within the product compartment that is
adapted and configured to create forced convection in the product
compartment and to be electrically powered by the voltage generated
by the at least one Seebeck module.
8. The container of claim 7, wherein each of the at least one
Seebeck module has: a cold side comprising a metallic surface that
is in thermal contact with the cryogenic mass via the cold plate or
one of the lateral surfaces; and a hot side in contact with the air
in the product compartment.
9. The container of claim 7, further comprising a radiator within
the product compartment that is adapted and configured to dissipate
coldness thereby allowing a temperature in the product compartment
to be lowered and/or maintained.
10. The container of claim 7, wherein the cryogenic compartment
further comprises a cryogenic reservoir that is adapted and
configured to be filled with the mass of cryogen.
11. The container of claim 7, wherein all of part of vertical walls
of the container are provided with metallic plates or a
low-emissivity coating for allowing a radiative effect to be set in
place within the product compartment.
12. The container of claim 7, wherein the cryogenic fluid is dry
ice.
13. A method of preserving and/or transporting perishable or
heat-sensitive products, comprising the steps of: providing the
isothermal container of claim 7; and cooling perishable or
heat-sensitive products through contact between the cold plate and
air from the product compartment.
14. The method of claim 13, further comprising the step of
transporting the products while stored in the isothermal
container.
15. The method of claim 13, wherein the cryogenic fluid is dry
ice.
16. The container of claim 13, wherein the at least one fan is used
only during a pull-down phase in which a temperature within the
product compartment is quickly lowered.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35
U.S.C. .sctn. 119 (a) and (b) to French patent application No. FR
1761996, filed Dec. 12, 2017, the entire contents of which are
incorporated herein by reference.
BACKGROUND
Field of the Invention
[0002] The invention relates to the field of transporting or
distributing perishable foodstuffs and other cooked meals or food
in isothermal containers, and that of heat-sensitive products
(drugs, vaccines, etc.), whether this for example be, in the case
of containers or trucks, where maintaining the cold chain is
ensured through the intervention of a refrigerant (cold gas,
cryogenic liquid such as liquid nitrogen, dry ice, etc.).
[0003] Thus, by way of example, central kitchens or alternatively
distribution centers use isothermal trolleys to transport and
distribute cooked meals or food from their kitchens or platforms to
the site(s) of consumption: hospital catering, company canteens,
school canteens, etc.
RELATED ART
[0004] The very numerous configurations of container and of types
of cooling available on the market, particularly the types of
isothermal container/trolley with or without physical cryogenic
compartment, with or without a reservoir ("cassette") containing
the cold fluid to be inserted into the container, etc. will not be
detailed exhaustively here.
[0005] Likewise, the refrigerant (gas, cryogenic liquid, solid,
whether this be nitrogen, CO.sub.2 or something else) may be placed
directly in the container or in a reservoir to be inserted inside
the container, or sent into an exchanger situated in the container,
or alternatively still, and again by way of illustration, sent into
a capacity situated in the container itself or nearby (or
alternatively affixed, for example when the container is a truck),
from which capacity fluid is drawn and sent to the container, to a
reservoir situated in the container, or to an exchanger situated in
the container, etc.
[0006] It can be seen from reading the foregoing that the
situations and configurations are highly varied.
[0007] By way of illustration however, it may be pointed out that
the cryogenic trolleys/containers are very often parallelepipedal
in shape, they very often comprise a cryogenic compartment arranged
in the upper part of the container, above the storage compartment
in which the products that are to be kept at a controlled
temperature are placed and, traditionally, this upper compartment
houses a reservoir intended to contain a refrigerant, for example
carbon dioxide in the solid phase, the sublimation of which
releases cold gases to compensate for the ingress of heat through
the joints between the container and its door or else through the
insulating walls of the container. The cooked meals (or other
perishable products) are then housed in the product storage
compartment of these isothermal containers, which are themselves
transported in trucks to the user site (hospital, school canteen,
office canteen, etc.).
[0008] Cooling occurs by contact between the air and the lower cold
plate of the cryogenic compartment or through the fact that the
lower face of the compartment is "holed" in order to allow cold gas
to pass toward the product compartment.
[0009] Depending on the version, the cryogenic compartment
comprises a heat screen affording protection to the stored
foodstuffs.
[0010] The phases of operation of such containers are generally as
follows:
[0011] 1--When the refrigeration system is started up after filling
(for example at the start of a round or alternatively after a door
has been opened), a mode is adopted in which the temperature is
rapidly lowered (this being known in the industry as the
"pull-down" phase).
[0012] 2--Once the reference temperature has been reached in the
product storage chamber, a control/regulation mode is adopted that
allows the temperature in the product storage chamber to be kept at
a reference value (this phase traditionally being known as the
"maintain" phase).
[0013] It is well known that the legislation currently in force
regarding compliance with the cold chain when transporting
perishable foodstuffs is becoming increasingly strict and notably
leading those involved with such food product distribution to make
changes in terms of preparation and in terms of the traceability of
the products that are to be transported.
[0014] Experiments successfully conducted by the applicant company
have revealed:
[0015] on the one hand, that the pull-down times for such
containers or trolleys, after filling with cryogen, are
particularly lengthy, often lasting several hours, and
[0016] on the other hand, that exchanges of heat in such systems
are far from being optimized.
SUMMARY OF THE INVENTION
[0017] It is then one of the objectives of the present invention to
propose a solution to the problems listed hereinabove.
[0018] As will be seen in greater detail in what follows, the
present invention therefore proposes implementing the following
means: [0019] the use of one (or more) fan(s) which will create
forced convection in the product compartment, this fan preferably
being operated only during the "pull-down" phases; [0020] the use
of one (or more) "Seebeck" module(s) exploiting the difference in
temperature between the cryogen (for example -80.degree. C. in the
case of dry ice) and the initial ambient temperature in the air of
the trolley when the cooling process began, making it possible to
generate a voltage, which is of particular benefit in electrically
powering the fan or fans in question. Experiments conducted by the
applicant company have demonstrated that the fan or fans generally
switch themselves off as soon as the voltage generated is no longer
sufficient to operate this (these) fans, something which generally
is the case at the end of the "pull-down".
[0021] It will be appreciated in fact that as the ambient
temperature in the product compartment reduces ("pulls down"), so
the temperature gradient decreases, resulting in a drop in the
amount of voltage generated, something that will progressively
cause the fan(s) to come to a standstill naturally and therefore
allow autonomous control of the ventilation.
[0022] It will therefore be appreciated that, in some instances,
the fan(s) may stop before the end of the pull-down phase. The
phase then continues without the aid of the forced convection, but
by natural convection, therefore somewhat like in the prior art,
i.e. through exchange between the cooled air near the cold plate
which forms the bottom of the cryogenic compartment, and the air
further away in the product compartment.
[0023] According to one of the advantageous implementations of the
invention, the trolley is fitted with means that allow a radiative
effect to be installed in the product compartment, for example via
the presence of metallic plates or of a low-emissivity coating
(paint, etc.) on all or part of the vertical walls of the trolley,
which radiation is of particular benefit during the "maintain"
phase.
[0024] According to one of the implementations of the invention,
the "Seebeck" effect is obtained by employing:
[0025] a "cold" side which is a metallic surface (for example made
of copper, of aluminum, or else of stainless steel) in contact with
the cold source (i.e. the addition of cryogen) for example with the
cold plate which forms the bottom of the cryogenic compartment or
one of the lateral surfaces thereof; and
[0026] a "hot" side which is embodied by the temperature of the
product compartment, which temperature is preferably maintained by
dissipating cold using a radiator by exchange with the air
prevailing in the product compartment.
[0027] Further features and advantages will become apparent from
the following description, given solely by way of example and made
with reference to FIGS. 1 and 2, which provide schematic depictions
of one embodiment of the invention.
BRIEF DESCRIPTION OF THE FIGURES
[0028] FIG. 1 is a schematic view of a container for preserving
and/or transporting perishable products.
[0029] FIG. 2 is a partial schematic view of the container of FIG.
1 that also illustrates the location of a Seebeck module used to
power a fan.
DETAILED DESCRIPTION OF THE INVENTION
[0030] FIG. 1 depicts an overall diagram of a container 1
preserving and/or transporting perishable products (of
parallelepipedal conventional structure equipped with an access and
loading door, not visible in this highly schematic figure), of the
type comprising a cryogenic compartment 2 able to receive a mass of
a cryogenic fluid, for example of dry ice, and a product storage
compartment 3 for the products to be preserved or transported,
situated in the bottom part of the container, where cooling takes
place by contact between the air of the product compartment and the
cold plate (10 in FIG. 2) that constitutes the lower part of the
cryogenic compartment.
[0031] This figure indicates the location of a "Seebeck" module 4
which will be detailed in the context of FIG. 2.
[0032] Note that this FIG. 2 is a schematic diagram providing
detail and a better understanding of one of the implementations of
the invention; it is not drawn to scale and is a kind of zoom in on
the "Seebeck" part quite simply permitting a better understanding
of this part.
[0033] This FIG. 2 shows the cold plate 10 that constitutes the
lower part of the cryogenic compartment 2, in contact with which is
positioned the "Seebeck" module 4, the two connectors of which are
connected to the fan 5.
[0034] The detailed view in the left-hand part of FIG. 2 shows one
example of a standard Seebeck module that can be used.
[0035] It is also possible to note the presence of a radiator 6,
for dissipating cold and thus lowering and/or maintaining a
temperature in the product compartment.
[0036] The experiments successfully conducted by the applicant
company demonstrated that a container according to the invention,
combining the presence of the fan and of the radiative heat
transfer, allowed the following results to be obtained:
[0037] an approximately +17% increase in the pull-down speed of the
product compartment after the loading of the cryogen
[0038] an approximately 45 min reduction in the duration of the
"pull-down" phase
[0039] in terms of the maintain phase, an approximately +58%
increase in the duration of this phase (therefore in the
temperature stability around the desired set point)
[0040] an at least 22% overall reduction in dry ice consumption for
a 58% improvement in maintain performance as signaled
hereinabove.
[0041] This lower mass of cryogen carried furthermore makes it
possible to increase the transported payload accordingly, and has a
direct beneficial effect on the cost of the technical solution
proposed here.
[0042] While the invention has been described in conjunction with
specific embodiments thereof, it is evident that many alternatives,
modifications, and variations will be apparent to those skilled in
the art in light of the foregoing description, Accordingly, it is
intended to embrace all such alternatives, modifications, and
variations as fall within the spirit and broad scope of the
appended claims. The present invention may suitably comprise,
consist or consist essentially of the elements disclosed and may be
practiced in the absence of an element not disclosed. Furthermore,
if there is language referring to order, such as first and second,
it should be understood in an exemplary sense and not in a limiting
sense. For example, it can be recognized by those skilled in the
art that certain steps can be combined into a single step.
[0043] The singular forms "a", "an" and "the" include plural
referents, unless the context clearly dictates otherwise.
[0044] "Comprising" in a claim is an open transitional term which
means the subsequently identified claim elements are a nonexclusive
listing i.e. anything else may be additionally included and remain
within the scope of "comprising." "Comprising" is defined herein as
necessarily encompassing the more limited transitional terms
"consisting essentially of" and "consisting of"; "comprising" may
therefore be replaced by "consisting essentially of" or "consisting
of" and remain within the expressly defined scope of
"comprising".
[0045] "Providing" in a claim is defined to mean furnishing,
supplying, making available, or preparing something. The step may
be performed by any actor in the absence of express language in the
claim to the contrary.
[0046] Optional or optionally means that the subsequently described
event or circumstances may or may not occur. The description
includes instances where the event or circumstance occurs and
instances where it does not occur.
[0047] Ranges may be expressed herein as from about one particular
value, and/or to about another particular value. When such a range
is expressed, it is to be understood that another embodiment is
from the one particular value and/or to the other particular value,
along with all combinations within said range.
[0048] All references identified herein are each hereby
incorporated by reference into this application in their
entireties, as well as for the specific information for which each
is cited.
* * * * *