U.S. patent application number 13/577483 was filed with the patent office on 2012-12-06 for fast freezer for bags with detection of the bag temperature.
This patent application is currently assigned to ANGELANTONI LIFE SCIENCE S.R.L. Invention is credited to Ciro Aprea, Maurizio Ascani, Maurizio Ragni, Alessandra Zamporlini.
Application Number | 20120305570 13/577483 |
Document ID | / |
Family ID | 42662717 |
Filed Date | 2012-12-06 |
United States Patent
Application |
20120305570 |
Kind Code |
A1 |
Aprea; Ciro ; et
al. |
December 6, 2012 |
FAST FREEZER FOR BAGS WITH DETECTION OF THE BAG TEMPERATURE
Abstract
A freezer for fluids inside bags comprises a freezing chamber
(11) containing a plurality of surfaces (13) for storing bags (20).
Each surface in turn comprises a refrigerated shelf (14) and an
associated uniformity plate (15) arranged above the shelf. The
plates (15) are hinged so as to be able to be raised from the
respective shelf in order to store bags between the shelf and the
plate. At least one of the uniformity plates (15) is provided with
a temperature sensor (18) for checking the temperature reached by
the bags on the shelf.
Inventors: |
Aprea; Ciro; (Napoli,
IT) ; Ascani; Maurizio; (Massa Martana (PG), IT)
; Ragni; Maurizio; (Perugia, IT) ; Zamporlini;
Alessandra; (Pantalla di Todi (PG), IT) |
Assignee: |
ANGELANTONI LIFE SCIENCE
S.R.L
Massa Martana (PG)
IT
|
Family ID: |
42662717 |
Appl. No.: |
13/577483 |
Filed: |
December 15, 2010 |
PCT Filed: |
December 15, 2010 |
PCT NO: |
PCT/IB10/55837 |
371 Date: |
August 7, 2012 |
Current U.S.
Class: |
220/592.02 |
Current CPC
Class: |
F25D 25/028 20130101;
A01N 1/0252 20130101; F25D 31/006 20130101 |
Class at
Publication: |
220/592.02 |
International
Class: |
F25D 23/00 20060101
F25D023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 12, 2010 |
IT |
MI2010A000218 |
Claims
1. Freezer for fluids inside bags, comprising a freezing chamber
(11) containing a plurality of surfaces (13) for storing bags (20),
each surface comprising in turn a refrigerated shelf (14) and an
associated uniformity plate (15) arranged above the shelf, the
plates (15) being hinged so as to be able to be raised from the
respective shelf in order to store bags between the shelf and the
plate, characterized in that at least one of the uniformity plates
(15) is provided with a temperature sensor (18) for indirect
verification of the temperature reached by the bags on the
shelf.
2. Freezer according to claim 1, characterized in that the sensor
(18) is connected to a system (23) for controlling operation of the
freezer which detects with this sensor that a given storage
temperature of the bags has been reached within a predefined time
interval.
3. Freezer according to claim 1, characterized in that the sensor
(18) is arranged on the plate (15) in order to measure the
temperature of a predetermined zone of the plate.
4. Freezer according to claim 3, characterized in that the
predetermined zone is a zone close to a side edge of the plate.
5. Freezer according to claim 3, characterized in that the
predetermined zone is at least partially defined by incisions (19)
in the plate.
6. Freezer according to claim 1, characterized in that the plate
with the sensor (18) is the plate associated with the lowest shelf
inside the chamber (11).
7. Method for checking for correct freezing of bags of fluid inside
a freezer of the type comprising a freezing chamber containing a
plurality of surfaces for storing bags, each surface comprising in
turn a refrigerated shelf and an associated uniformity plate
arranged above the shelf, the plates being hinged so as to be able
to be raised from the respective shelf in order to store bags
between the shelf and the plate, the method comprising the steps of
detecting the temperature of at least one zone of a uniformity
plate resting on at least one bag and using the value measured as
an indication of the temperature reached by the bags on the
shelves.
8. Method according to claim 7, wherein it is considered that a
predetermined storage temperature of the bags has been reached when
the temperature detected in the said plate zone is less than said
predetermined storage temperature by a predefined amount.
9. Method according to claim 8, wherein it is considered that the
predetermined storage temperature is equal to or less than
-30.degree. C. and the predefined amount is at least -10.degree.
C.
10. Method according to claim 7, wherein it is considered that the
predetermined storage temperature of the bags has been correctly
reached if the temperature detected in the said plate zone reaches
a value lower than said predetermined storage temperature by said
predefined amount within a predefined time interval following
introduction of the bags into the freezer.
Description
[0001] The present invention relates to a fast freezer for fluids
inside bags, in particular bags of plasma.
[0002] Fast freezers for fluids inside bags which use a "contact"
system for freezing are known in the prior art. These freezers
comprise a plurality of shelves arranged above each other and
individually refrigerated (for example to a temperature of
-75.degree. C.), each being associated with a non-refrigerated
metal plate, called a uniformity plate, which is arranged above the
shelf so as to rest thereon and which is hinged so as to be able to
be raised from the surface of the shelf, allowing the bags to be
arranged on or removed from the shelf itself.
[0003] During "idle" operation of the machine each uniformity plate
is pre-cooled by contact with the respective refrigerated shelf.
The bags to be frozen are then placed in an orderly manner on each
shelf so that they are compressed between the shelf and the
associated uniformity plate.
[0004] Initially the uniformity plate "releases cold" to the bags.
Subsequently, however, it is the bags which, by means of
conduction, cool the uniformity plate. This allows rapid lowering
of the temperature of the bag contents.
[0005] It is important, however, to know the temperature of the
fluid inside the bags. For example, it is important to ensure that
the bags reach a desired storage temperature within a predetermined
time interval. In the case of bags of plasma, for example, it is
envisaged that, in order to guarantee correct storage, they must
reach a temperature lower than -30.degree. C. within one hour of
being introduced into the freezer.
[0006] In order to be able to check that the cooling cycle is being
performed correctly and be able to detect the end of the cycle
(namely reaching of the storage temperature), the use of a dummy
bag, or sample bag, which does not contain plasma, but is provided
internally with a temperature sensor, has been proposed. Assuming
that, during the cooling cycle, the temperatures inside the sample
bag and real bags evolve in a substantially similar manner, the
sample bag is positioned on a tray together with the normal bags to
be frozen and the detection performed by its sensor is used as a
measurement of the temperature of the bags, in order to check the
time needed to reach the predetermined minimum storage temperature
(for example, -30.degree. C.).
[0007] This system suffers from the drawback that it requires the
user to position suitably the sample bag at the start of each
freezing cycle. Moreover, the connections between the sensor inside
the sample bag and the control and signalling system which manage
the freezer may take up space and get in the way during
introduction and extraction of the bags. A further drawback is that
the use of the sample bags reduces the real loading capacity of the
freezer.
[0008] The general object of the present invention is to provide a
detection method and a freezer for bags, of the type with
uniformity plates, which allows easy verification of the storage
temperature reached by the bags and reliable checking of the bag
cooling cycle.
[0009] In view of the above object the idea has arisen to provide,
according to the invention, a freezer for fluids inside bags,
comprising a freezing chamber containing a plurality of surfaces
for storing bags, each surface comprising in turn a refrigerated
shelf and an associated uniformity plate arranged above the shelf,
the plates being hinged so as to be able to be raised from the
respective shelf in order to store bags between the shelf and the
plate, characterized in that at least one of the uniformity plates
is provided with a temperature sensor for indirectly checking the
temperature reached by the bags on the shelf.
[0010] Still according to the invention, the idea has arisen to
provide a method for checking for correct freezing of bags of fluid
inside a freezer of the type comprising a freezing chamber
containing a plurality of surfaces for storing bags, each surface
comprising in turn a refrigerated shelf and an associated
uniformity plate arranged above the shelf, the plates being hinged
so as to be able to be raised from the respective shelf in order to
store bags between the shelf and the plate, the method comprising
the steps of detecting the temperature of at least one zone of a
uniformity plate resting on at least one bag and using the value
measured as an indication of the temperature reached by the bags on
the shelves.
[0011] In order to illustrate more clearly the innovative
principles of the present invention and its advantages compared to
the prior art, an example of embodiment applying these principles
will be described below, with the aid of the accompanying drawings.
In the drawings:
[0012] FIG. 1 shows a partial, schematic perspective view of a
freezer designed according to the principles of the invention;
[0013] FIG. 2 shows a cross-sectional schematic view of a detail of
the freezer according to FIG. 1.
[0014] With reference to the figures, FIG. 1 shows a freezer,
denoted generally by 10, designed according to the invention. The
freezer 10 comprises a freezing chamber 11 which is thermally
insulated and closed by an access door 12 for the refrigerated
storage of fluid inside bags. The chamber contains a plurality of
surfaces 13 for the orderly arrangement of the bags to be
refrigerated (schematically indicated by 20 in FIG. 2). The bags
contain biological fluids, in particular plasma, which must be
frozen at a predefined temperature within a predetermined time
interval in order to be able to guarantee correct storage
thereof.
[0015] Each surface 13 comprises in turn a refrigerated shelf 14
associated with a uniformity plate 15 made of thermally conductive
material and arranged above the shelf so as to rest with its bottom
surface against the top surface of the shelf, which is also made of
thermally conductive material (for example, anodized aluminium).
The plate 15 is hinged at the rear at 16 so that it can be raised
from the surface of the shelf by means of a special handle 17.
[0016] At least one of the uniformity plates is provided with a
temperature sensor 18 advantageously positioned on the top surface
of the plate in order to detect the temperature of said surface.
The sensor 18 may advantageously have a length approximately
comparable to the dimensions of a bag which can be stored between
plate and shelf. For this purpose, the sensor may be of the
composite type, namely formed for example by several sensors
distributed at various points along said length and connected so as
to have a temperature measurement which is the mean of the
temperatures detected at these points. The position of the sensor
18 on the plate advantageously coincides with the underlying
position for storing a bag on the associated shelf, as can be seen
more clearly in FIG. 2. In particular, the zone of the plate which
contains the sensor is close to a side edge of the plate.
[0017] As can be seen again in FIG. 1 and, more clearly in FIG. 2,
the zone of the uniformity plate containing the sensor 18 is
advantageously defined by incisions 19 which are formed in the
plate at least in the transverse direction (namely in the direction
transverse to the rear hinging axis of the plate and to the access
opening of the freezing chamber 11). The incisions 19 have the
function of reducing the heat transmission between the plate zone
supporting the sensor and the rest of the plate so that the
temperature detected is influenced minimally by external factors.
It is obviously possible to use one or more sensors 18 for each
shelf inside the freezer. However, to avoid having to measure the
temperature on each shelf, it has been found to be advantageous to
position the sensor 18 only on the uniformity plate resting on the
shelf where the bags reach last the desired storage temperature.
The position of this shelf inside the chamber 11 depends on the
constructional characteristics of the freezer and can be easily
determined at the design stage. Usually the configuration of the
system and the freezing chamber is such that the bags placed on the
bottom shelf are the last to freeze and therefore usually the
sensor is positioned on the plate of this bottom shelf.
[0018] Obviously, in the case of a sensor on a single uniformity
plate, loading of the bags must be performed preferably starting
from the shelf associated with said plate. In this way, if loading
of the bags is performed starting from the shelf provided with the
sensor and, in particular, from the zone situated underneath the
sensor, there is the guarantee, by means of the measurement
performed on a single shelf, that "safety" conditions exist also
for the bags situated on the other shelves.
[0019] As schematically shown in FIG. 2, the bags (arranged for
example in an orderly manner in rows and columns on each shelf) are
compressed between the plate and the shelf. The hinging axis 16 may
also be provided with a known articulation (not shown) so as to
adapt automatically the distance between plate and shelf depending
on the thickness of the bags inserted between them, so as to keep
the facing surfaces of plate and shelf substantially parallel. In
this way, when there are no bags at all, the plate may be rested
with its bottom surface in contact with the top surface of the
shelf, while when the bags are present it may press uniformly
against the bags themselves, compressing them with its weight
against the shelf. A spring for providing an additional thrusting
force may also be provided.
[0020] As can be seen schematically in FIG. 2, the metal surface of
each shelf is cooled by a cooling circuit 21 which forms part of a
known refrigeration system 22 which can be easily imagined by the
person skilled in the art and therefore need not be further
illustrated and described here. The cooling temperature of the
shelves may be advantageously in the region of -75.degree. C.
[0021] The sensor 18 is connected to an electronic system 23 for
controlling operation of the freezer, which is equipped with a
device or console 24 for displaying and entering commands and which
is accessible from the outside of the freezer. The control system
(for example of the type with suitably programmed microprocessor)
and the display and command device (for example equipped with
monitor, display and/or indicator lamps and command keyboard and/or
pushbuttons) are known per se and can be easily imagined by the
person skilled in the art. They shall therefore not be further
shown or described here.
[0022] During use of the freezer, after the known stage of idle
pre-cooling of the freezer (with all the uniformity plates resting
against the respective refrigerated shelf), the bags may be loaded
in an orderly manner on the shelves, starting from the position
where the sensor 18 is present.
[0023] The control system checks the temperature detected by the
sensor so as to be able to determine that the desired temperature
for storage of the bags has been reached within the set time
interval.
[0024] Usually the temperature detected will first show an increase
due to the initial release of heat to the plate by the bag situated
underneath the sensor. After this, the temperature detected will
start to drop following transmission of heat between plate, bag and
refrigerated shelf. The values recorded during this temperature
drop provide an indication of the temperature of the bags being
cooled. Obviously, the temperature detected will generally be lower
than the real temperature of the bags, but the difference may be
easily taken into account during calibration of the system. There
is in fact no need for a precise measurement of the temperature
reached by the bags, but an indication that a threshold value for
correct storage (for example, -30.degree. C.) has at least been
reached. It may thus be considered that at least one predetermined
temperature for storage of the bags has been reached when the
temperature detected by the sensor is less than said storage
temperature by a given amount. For example, it has been found that,
when in the freezer described the temperature sensor on the plate
indicates a temperature of less than -40.degree. C., there is the
certainty that the underlying bag is at a temperature lower than
-30.degree. C. The predefined amount for the temperature difference
is therefore advantageously -10.degree. C.
[0025] The control system may therefore detect (and if necessary
signal by means of the device 24) that the storage temperature has
been reached and check that the time taken is in keeping with the
predetermined parameters, for example that it takes less than one
hour to reach -30.degree. C., as stipulated by the standards for
the storage of bags of plasma. The result of this check may also be
indicated on the device 24 and if necessary stored for future
use.
[0026] With the method according to the invention it may be
considered that the predetermined freezing temperature of the bags
has been correctly reached if the temperature recorded in the given
plate zone reaches a value lower than said freezing temperature by
the predefined amount within a predefined time interval
(advantageously one hour) following introduction of the bags into
the freezer. It is therefore possible to know indirectly whether
the bags of plasma have been correctly frozen.
[0027] At this point it is clear how the predefined objects have
been achieved, by providing a freezer for bags in which indirect
verification of the temperature of the bags of plasma is obtained
by means of measurement of the temperature of specific point or
zone of at least one uniformity plate, resulting in the certainty
of obtaining, for example, a value indicating that a real threshold
temperature for correct storage of the bags has been reached.
[0028] The system according to the invention does not reduce the
useful space inside the freezer and does not require the user to
perform particular operations, apart from that of loading the bags
of plasma starting from a certain predetermined position. This
therefore results in easier use compared to the known systems which
use sample bags with internal sensors.
[0029] Obviously, the above description of an embodiment applying
the innovative principles of the present invention is provided by
way of example of these innovative principles and must therefore
not be regarded as limiting the scope of the rights claimed herein.
For example, as mentioned above, several sensors may be provided on
the same plate or on or more than one plate, so as to have more
extensive measurements of the temperature, which may then be
suitably processed, if necessary, by means of the freezer control
system. Moreover, although a shelf with two bags aligned along the
depth is shown (for example, intended for bags of the "detachable"
type), it is also possible to store different size bags, for
example bags which have a length corresponding to the full depth of
the shelf, as for example in the case of plasmapheresis or
apheresis bags.
[0030] The incision in the uniformity plate extending along the
whole working depth of the plate (as, for example, shown in the
figures) allows isolation of the plate zone intended to store two
bags or the long bag and in this way allows in both cases correct
measurement by the sensor.
* * * * *