Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02621045 2008-02-14
BUILD-UP MONITORING SYSTEM FOR REFRIGERATED ENCLOSURES
CROSS-REFERENCE TO RELATED APPLICATION
This patent application claims priority on United
States Provisional Patent Application No. 60/890,290, filed
on February 16, 2007, by the present Applicant.
BACKGROUND OF THE APPLICATION
1. Field of the Application
The present application relates to refrigerated
enclosures of the type used in supermarkets and the like to
store foodstuff and, more particularly, to a draining of
liquid in such refrigerated enclosures.
2. Background Art
In supermarkets, grocery storages, and industrial
storage, amongst other applications, refrigerated enclosures
are commonly used to maintain foodstuff at suitable
temperatures, or to freeze the foodstuff in order to
preserve its freshness.
Referring to Fig. 1 of the prior art, a
refrigerated enclosure is generally illustrated at 10. The
refrigerated enclosure 10 is defined by a casing 11 that
forms an outer shell of the enclosure 10, and within which
specific temperature conditions are maintained. Shelves 12
are provided as support for the foodstuff (not shown) that
will be refrigerated/frozen in the enclosure 10. A drain
basin 13 is provided at a bottom of the casing 11. As such,
any residual liquid will be drained via the sloping of the
drain basin 13, to the drain 14/siphon 15.
It is observed that the refrigeration unit 16 is
in the drain basin 13. The refrigeration unit 16 is
typically coils in which a refrigerant circulates, and upon
which coils ambient air is blown.
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Because of the low temperatures associated with
refrigerated enclosures, there is a risk that the residual
liquid to be drained by the drain basin 13 will freeze.
Moreover, as the refrigeration unit 16 is in some cases
adjacent to the drain 14, the temperatures adjacent to the
drain 14 are lower than the temperature at the shelves 12,
increasing the risk of freezing of the residual liquids. A
solid build-up can damage the refrigerated enclosure. For
instance, coils of the refrigeration unit 16 have broken
because of ice build-ups in the drain, resulting in
refrigerant leakage, emergency transfer of foodstuff, and
even temporary store closure for maintenance of the
refrigeration system.
SUMMARY
It is therefore an aim of the present application
to provide a drain monitor system for refrigerated
enclosures that addresses issues associated with the prior
art.
Therefore, in accordance with the present
application, there is provided
Further in accordance with the present
application, there is provided a build-up monitoring system
in combination with a refrigerated enclosure, comprising: a
refrigerated enclosure having a drain, a drain basin and a
refrigeration unit adapted to maintain refrigerating
conditions in the refrigerated enclosure; a build-up
detector positioned with respect to the refrigerated
enclosure so as to monitor a level of build-up in the
drain/drain basin; a condition analyzer for receiving
detection data from the build-up detector, the condition
analyzer identifying from the detection data a build-up in
the drain/drain basin requiring an intervention; and an
interface for indicating the requirement for the
intervention.
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Further in accordance with the present
application, there is provided a method for identifying a
build-up requiring an intervention in a drain/drain basin of
a refrigerated enclosure, comprising: positioning a
build-up detector in the refrigerated enclosure; monitoring
detection data from the build-up detector; identifying a
build-up condition by comparing the detection data with at
least one predetermined parameter value for a given time
period; and indicating the requirement for an intervention
from the build-up condition.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a sectioned elevation view of a
refrigerated enclosure in accordance with the prior art;
Fig. 2 is a block diagram illustrating a build-up
monitoring system for refrigerated enclosures, in accordance
with an embodiment of the present application;
Fig. 3 is a printout of a user-interface screen as
used with the build-up monitoring system of Fig. 2; and
Fig. 4 is a flowchart of a method for identifying
a build-up requiring an intervention in a drain/drain basin
of a refrigerated enclosure in accordance with another
embodiment of the present application.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to Fig. 2, a build-up monitoring
system in accordance with an embodiment is generally shown
at 20. The monitoring system 20 is used in conjunction with
a refrigerated enclosure such as the one illustrated at 10
in Fig. 1. The monitoring system 20 is provided to monitor
the refrigerated enclosure for ice build-ups in the drain
basin 13, and to alarm maintenance personnel when
predetermined levels of build-ups are detected.
The monitoring system 20 has a control system 21,
which includes a processing unit. The control system 21 is
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typically part of a main controller used to operate the
refrigeration system of a store/building.
A build-up detector 22 is connected to the control
system 21. The build-up detector 22 is positioned within
the refrigerated enclosure to monitor ice build-ups, by
monitoring the drain basin 13, the drain 14 and/or the coils
16 of the refrigeration unit.
A plurality of configurations are considered for
the build-up detector 22. In a first embodiment, the
build-up detector 22 is a thermocouple or thermometer
positioned within the drain basin 13 and/or in contact with
the drain 14. As such, any ice build-up will result in a
stabilization of temperature that will be identified by the
monitoring system 20.
In a second embodiment, the build-up detector 22
is an optical sensor that will visually monitor the presence
of an ice build-up beyond a predetermined level. Different
types of optical sensors are considered with, for instance,
emitters/receivers, etc.
In a third embodiment, sensors from other
industries can be used in the monitoring system 20. For
instance, U.S. Patent No. 5,296,853, issued to Federow
et al. on March 22, 1994, discloses a laser ice detector,
components of which can suitably be used to form the
build-up detector 22. It is also considered to use infrared
sensors.
The control system 21 receives detection data from
the build-up detector 22, and transmits the data to the
condition analyzer 23. The condition analyzer 23 is
provided to detect ice build-up from the detection data.
The condition analyzer 23 triggers an alarm signal once ice
build-up beyond a predetermined level is identified by the
condition analyzer 23.
In the embodiment in which the build-up detector
22 is a thermocouple, detection parameters are provided to
the condition analyzer 23 by way of a database 24 with such
detection parameters. For instance, the detection
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parameters are a temperature set-point limit or a
temperature range along with a time period, whereby
detection of a temperature above the set-point limit for
more than the time period will have the condition analyzer
23 trigger the alarm signal.
The time period used by the condition analyzer 23
filters out punctual perturbations, such as the shelving of
new products that are at room temperature. In such cases,
liquids dropping from these products and reaching the drain
are temporarily above refrigerated temperatures, and should
not be considered as a build-up. Therefore, monitoring such
temperatures for an extended time period allows the products
to cool down prior to an alarm being triggered.
Moreover, the time period can be used to monitor
temperature variations. For instance, temperature readings
in refrigerated enclosures 10 vary as a function of numerous
factors: refrigerant temperature, air temperature, enclosure
doors being opened, new products being shelved in the
enclosure 10. If there is a build-up on the build-detector
22 measuring the temperature, the build-up will act as
thermal insulation that will generally prevent temperature
variations in the readings of the detector 22. Accordingly,
in an embodiment, a uniform temperature over an extended
time period is identified as a build-up by the condition
analyzer 23.
The database 24 is writable, such that the
detection parameters are changeable. For instance, if a
defrost cycle is run to melt frost on the coils, it may be
required to change the detection parameters in the database
24, although it is preferred that the detection parameters
be set so as to exclude a defrost cycle from being detected
as ice build-up. Another example in which it is required to
change the detection parameters is when the temperature of
operation of the refrigerated enclosure is changed (i.e.,
going from refrigerating meats to vegetables).
In the embodiment in which the build-up detector
22 is an optical sensor or like sensor, the detection data
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may simply be decoded by the condition analyzer 23, such as
to identify detected build-up signals from the detection
data. The database 24 of detection parameters may represent
a filter to ensure that the alarm signal is not triggered
accidentally. For instance, if an attendant triggers
accidentally the optical sensor into detecting an ice
build-up, the detection parameters are typically set to
prevent an alarm being triggered by such action.
It is considered to provide the monitoring system
20 with a plurality of build-up detectors 22, with
complementary features. For instance, optical sensors can
be used in combination with thermocouples, to increase the
accuracy of the detection.
Still referring to Fig. 2, the monitoring system
20 has an interface 25 that may be used to display the
detection data in suitable format. For instance, referring
to Fig. 3, a GUI screen 25A is illustrated, and shows a
temperature detected in a refrigerated enclosure as a
function of time. It is seen that a graph shows a pair of
peaks on screen. The peaks are typically the result of
defrost cycles being run to remove frost on the coils of the
refrigeration units 16 (Fig. 1). The interface 25 may
project data that is viewed on a periodic basis by an
operator so as to detect ice build-up.
Alternatively, an alarm 26 may be provided,
whether on site or through the interface 25 (e.g., in the
form of a pop-up window) , to indicate that maintenance is
required to clear up the drain/drain basin.
The build-up monitoring system 20 described above
may be conveniently retrofitted to existing refrigerated
enclosures, such as refrigerated enclosure 10 of Fig. 1.
More specifically, considering that most industrial refri-
geration systems have a centralized processing unit, the
condition analyzer 23 may be installed in the centralized
processing unit, with the build-up detector/detectors 22
being connected to the centralized processing unit (e.g.,
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to provide the detection data to the condition
wireless)
analyzer 23.
Fig. 4 generally illustrates an embodiment for
implementing the method for identifying a build-up requiring
an intervention in a drain/drain basin of a refrigerated
enclosure at 30.
In Step 32, at least one of the build-up detectors
22 is installed in the refrigerated enclosure 10 so as to
monitor the drain basin 13 or drain 14 for ice build-ups.
In Step 34, the detection data provided by the
build-up detector 22 is monitored. The monitoring is
continuous, but may be paused in maintenance periods, such
as during a defrost cycle.
In Step 36, a build-up condition is identified
from monitoring of the detection data over a given time
period. The detection data is as a function of the types of
build-up detector 22 selected: temperature, visual presence
of build-up.
In Step 38, indication is made to maintenance
personnel that an intervention is required due to a build-up
condition. For instance, maintenance personnel on-site or
off-site may be warned by way of an alarm.
