Note: Descriptions are shown in the official language in which they were submitted.
CA 02637861 2008-07-09
Keg beer cooling and dispensing line
Field of the Invention
The utility invention relates to beverage cooling systems or lines. Such lines
are
installed at cafes, bars, restaurants and other catering establishments for
cooling and
dispensing of beverages, including keg beer.
Background of the Invention
Numerous keg beer cooling and dispensing devices and systems are known, such
as
PRE-MIX system for semi-finished product, namely, keg beer that before usage
should be
saturated with carbon dioxide (carbonated) and cooled to dispensing
temperature of 6 to 10 C
depending on beer grade. Such systems may be installed above or under
dispensing stand.
The above-stand set of equipment has small dimensions and can dispense 10 to
35
liters per hour of one or two, sometimes tluee, beer grades. Beer cooling and
dispensing
systems installed under the stand are larger and more expensive, their
capacity being in the
range of 25 to 250 liters per hour, serving two to fourteen grades of beer.
Many bars and similar outlets possess beer distribution systems. Beer is
stored in kegs
witliin a large cooling chamber or a small refrigerating chamber. Dispensing
columns are
comlected to one or more beer lines joined to one or more beer distribution
hoses depending
on the number of beer grades. Beer distribution hoses come from the cooler to
dispensing
elements. Each beer hose should be connected to supply system that distributes
a grade of beer
to various dispensing elements at the bar. Additionally to beer dispensing
hoses, usually one or
more cooling hoses come along beer dispensing hoses from cooling chamber to
final
dispensers. Those cooling hoses usually run nearby beer dispensing hoses,
sometimes they
form rings or spirals around beer dispensing hoses. Cooling hoses serve to
maintain beer cool
as it is fed from kegs to beer distribution tower at cooling chamber.
Beer coolers may be water (running) or dry cooled. In the first case water is
poured
into a tub and cooled by compressor. Coils witli beer within and a pump are
submerged into
the water tub, the pump takes off cold water and pumps it along a separate
pipeline running
parallel to beer line up to dispenser, thus, beer is accompanied by cold water
and dispensed in
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CA 02637861 2008-07-09
cold state. This system is called "python". In dry-type beer coolers the tub
containing beer
lines and cooling loop is filled with a special gel or aluminum. Dry beer
coolers reach
operational condition faster, they can operate 7-10 minutes after switcliing,
whereas water
coolers need more than one hour to attain their freezing capacity. At the same
time dry coolers
are much more expensive and, therefore, their usage is quite limited. Beer
cooling and
dispensing equipment has nominal seivice life at least 6-8 years with the
proviso of continuous
maintenance. Cooler capacity lies within 30 to 1801iters per hour. Most
popular at roll bars
are two-grade beer coolers producing 60 liters per hour. In areas with suminer
ambient
temperature above 30 C special large-size "TROPIC" coolers operate at
sufficiently large
establishments.
Fluid cooling device, dispensing apparatus for cooled fluid containing same,
and
process of sterilization tliereof (Russian Application N2 2005122473 of
2007.01.27).
comprises a primary heat exchanger; secondary heat exchanger; first pipeline
with circulating
cooled fluid; coolant transferring cooling energy to fluid to be cooled
circulating in the first
pipeline; primary and secondary heat exchangers being situated at least in
part within one
another.
This device may cool beverages, including beer, but it has some substantial
drawbacks.
Its design is too complicated, which hampers installation at small bars or
restaurants that do
not have sufficient area to arrange all elements of this equipment. The
device, complicated and
bulky as it is, is unable to maintain beer cooled along the hose and does not
enable to vary
hose length in the course of installation and commissioning. In this device
the beer hose length
is fixed at engineering project, and in case of this length being changed
additional design
engineering is necessary.
The closest solution to this utility invention as regards the technical
essence and
expected result is described in application Beverage dispensing system linear
amplifien> (see
WO/2004/16545 of 26.02.2004) by ICEFLOE TECHNOLOGIES INC. [CA/CA]). In this
solution a beverage cooling and dispensing systezn comprises:
- a source of beverage;
- at least one beverage distributing element;
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CA 02637861 2008-07-09
- at least one distributing hose for beverage supply from the source to the
distributing element
with heat transfer element disposed separate from beverage source for
submersion of at least
distributing hose to cooling tub.
Heat transfer element prevents heating of beverage, such as beer, due to large
distance
between distributing beverage lines. Besides, heat transfer element in ready
condition includes
a chamber that defines capacity. The first inlet pipe introduces cooling fluid
into the chamber.
First inlet pipe and first outlet pipe are not connected within the chamber so
that cooling fluid
might accumulate within the chamber space.
The second pipe in the chamber includes inlet and outlet openings on chamber
surface.
The second pipe passes throughout the whole chamber to separate it from
cooling fluid within
the chamber.
The system also conlprises a heat transfer element for beverage distribution
system
wherein the source of beverage is arranged at some distance from beverage
distribution
element, the beverage being fed thereto along the beer distributing line.
This solution refers to both beer dispensiag and beer cooling systems
installed at bars
and able to cool the beverage and to reduce its foaming during dispensing.
Nevertheless, this solution also has a number of substantial drawbacks. The
inventors
state that this system is able to maintain beer temperature at dispenser
outlet at the level of
about 28 F (equivalent to - 2.22 C), which is only a medium point of claimed
beer cooling
temperature range (-5 C to -0.5 C). But, as the temperature of cooling fluid
in the device
under WO/2004/16545 of 26.02.2004 is 32-34 F (0-1,(1) C) we cannot understand
how the
claimed beer temperature at dispenser outlet - near 28 F (equivalent to - 2.22
C) may be
attained. Besides, the inventor of WO/2004/16545 of 26.02.2004 claims beer
temperature at
dispenser outlet near 28 F (equivalent to - 2.22 C), whereas according to
"Manufacturing
process of special beer "BALTIKA Honey Strong "(see Russian Patent Ns 2186841)
ready
beer before clarification by filtering through kieselguhr is clarified in
separators and then
deeply refrigerated up to (-0.5) -(-3) C...... Beer refrigeration temperature
up to Ao (-3) C is
met in other sources of infomiation and patent documents as well. Beer cooling
up to (-4) C is
also known. Thus, it is quite evident that beer does not have a constant
freezing point =28 F
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CA 02637861 2008-07-09
(or - 2.22 C) as inventors of WO/2004/16545 of 26.02.2004 claim; beer freezing
point
depends from composition, den.sity and other parameters of different grades.
Thus, the following reasons lie in the background of the novel keg beer
cooling and
dispensing line.
1. Traditional "wet" or "running" type beer coolers cannot maintain stable
product
temperature at cooler outlet. Therein the stability of temperature maintenance
depends on
depletion of accumulated ice bank, i.e. as the accumulated ice bank depletes,
beer temperature
at cooler outlet increases. To restore the depleted ice a substantial period
of time is necessary,
40 minutes and more, which is unfavorable for stability of beer temperature at
cooler outlet.
Dry block devices proposed as additional beer coolers possess substantially
accurate
maintenance of aluminum dry block teinperature and are quickly restored. This
circumstance
is in favor of stable maintenance of the product exit teinperature.
2. Traditional coolers are installed either above or under bar stand and all
are equipped
with air condensers. We propose herein to use a dry block cooler, its
dimensions being equal
to those of a small above-stand cooler, bit disposed under the stand, thus
saving important
space of bar stand and underneath. Our cooler is equipped with a water
condenser to avoid
excessive heat release under or above the stand, as it is usual in traditional
air condensers.
Excessive heat release created by traditional air condensers makes
uncomfortable environment
for bartender and customers by heating the space near bar stand. It is
especially felt in
summer. The heated air surrouuding the stand is also unfavorable for adequate
operation of
other bar equipment: juice cooler, ice generator, etc.
Besides, water condenser permits a more stable cooler cycle. The operation of
any
refrigerating machine depends on ambient temperature. Any condenser of
refrigerating
macliine is a heat-emitting element of refrigerating loop, so it should be
cooled. In case of its
cooling due to ambient air circulation perfonned by condenser fan it is called
"air eondenser".
Under sufficiently high temperature of ambient air at condenser entrance, as
in summer,
condenser cooling becomes inadequate and the productivity of refrigerating
machine reduces.
Summary of the Invention
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CA 02637861 2008-07-09
The aim of proposed solution is development of a keg beer cooling and
dispensing line
able to ensure beer cooling during its travel along beer feed line as well as
a stable temperature
in the range of -5 C to -0.5 C at dispenser entrance.
The solution is based on the task to improve a keg beer cooling and dispensing
line
coinprising a dispenser, connecting beer feed line in the form of a python
hose, keg beer
storage chamber, necessary and sufficient number of beer kegs, basic cooling
device LCB -
200G POLAR, so that in accordance with the utility invention the line
additionally comprises
a second cooling device LCB - 200D POLAR, forming a part of the general keg
beer
refrigeration and dispensing loop, water condenser of additional cooling
device is cooled with
propylene glycol whose adequate temperature is maiirtained by the basic
cooling device LCB -
200G POLAR, feed of propylene glycol to water condenser of additional cooling
device LCB
- 200D POLAR is controlled by water regulating valve (WRV), whereas the basic
cooling
device LCB - 200G POLAR includes a propylene glycol container and a soldered
plate heat
exchanger filled with necessary amount of freon from thermal regulating valve
(TRV), and
additional cooling device LCB - 200D POLAR includes a freon-type water
condenser wherein
a water regulating valve (WRV) maintains a stable condensation temperature,
whereas
connecting beer feed line is able of triple and more circulation of cooling
liquid along the total
length of beer feed line.
Novelty of the proposed solution lies in the fact that contrary to traditional
keg beer
cooling and dispensing lines the applied for line comprises an additional
cooling device LCB -
200D POLAR, forming a part of the general keg beer refrigeration and
dispensing loop. Water
condenser of additional cooling device is cooled with propylene glycol whose
adequate
temperature is maintained by the basic cooling device LCB - 200G POLAR, feed
of propylene
glycol to water condenser of additional cooling device LCB - 200D POLAR is
controlled by
water regulating valve (WRV), thus, one can not only reduce temperature at
dispenser exit to a
value in the range of -5 C to -0.5 C, but also support continuous beer
dispensing at the rate up
to 212 liters per hour within 15 minutes; water regulating valve (WRV) permits
regulation of
feed of cooling liquid (propylene glycol) to water condenser of additional
cooling device LCB
- 200D POLAR to the amount depending of beer feed line length..
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CA 02637861 2008-07-09
Inventor step of the solution lies in the fact that the additional cooling
device favors
additional cooling of the basic cooling system loop and its elements, thus
leading to attainment
of established aim - to ensure temperature of beer at dispenser exit within
the range -5 C to -
0.5 C, depending on beer grade.
Keg beer cooling and dispensing line according to the utility invention
permits beer
cooling to temperature at dispenser exit witllin the range -5 C to -0.5 C,
ensuring continuous
beer dispensing at the rate up to 212 liters per hour within 15 minutes. This
means that the line
is able to dispense one keg of beer within 15 minutes, maintaining its
temperature in vials
within the range of -5 C to -0.5 C. The line is capable of 45 minutes
continuous dispensing,
after which it requires 5 minutes to resume continuous operation.
Brief Description of the Drawings
In the accompanying drawings, which illustrate an exemplary embodiment of the
present invention:
Figure 1 is a schematic illustration of a keg beer cooling and dispensing line
according
to the present invention installed in a bar, caf6, restaurant or other
catering establishment.
Figure 2 is a schematic flow diagram of the keg beer cooling and dispensing
line.
Figure 3 is an end elevational view of a basic cooling device (LCB - 200G
POLAR) of
the keg beer cooling and dispensing line.
Figure 4 is a side elevational view of the basic cooling device (LCB - 200G
POLAR).
Figure 5 is an end elevational view of the basic cooling device (LCB - 200G
POLAR)
opposite the end elevational view of Figure 3.
Figure 6 is a perspective view of the basic cooling device (LCB - 200G POLAR)
with
a cover thereof removed for illustration.
Figure 7 is an overliead plan view of the basic cooling device (LCB - 200G
POLAR).
Figure 8 is another perspective view of the basic cooling device (LCB - 200G
POLAR).
Detailed Description of Preferred Fmbodinments
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CA 02637861 2008-07-09
Let us discuss line operation in more detail. Beer cooling line has reached
operational
readiness. Maximum continuous load of 212 L/h beer is fed, being cooled
cooling to
temperature within the range -5 C to -0.5 C, for 15 minutes. This is working
mode of the line.
For 15 minutes of intense operation the line cooled and dispensed a whole keg
of beer. Then
shutting dispenser tap and the line rehirns to initial position stops
continuous dispensing. This
is resuming mode lasting for 5 minutes. After resuming the line begins again
continuous feed
and cooling of product, thus restarting a new cooling cycle. Cooling cycle
means a period
when the line finishes its working and resuming modes. Beer fed to the line
should be stored
in kegs at a cooled premise or at a special refrigeration chamber wherein air
temperature is
maintained at the level 3.5 C. Precooling of beer in kegs to the temperature
of 3.5 C takes
place at this storage before feeding to the line. As a rule, such storage
chambers exist at all
beer restaurants, large bars, cafe, etc., as shown in Fig.l.
Fig. 2 shows the flow diagram of the proposed beer cooling line. As seen from
the
diagram, beer is fed to heat exchanger unit 3 along python hose and propylene
glycol cooled at
heat exchanger 9 is also fed therein, thus maintaining constant temperature of
beer to be
additionally cooled at heat exchange unit 3. The beer cooling line comprises
two cooling
devices, naniely LCB - 200G POLAR and LCB - 200D POLAR.
Keg beer cooling and dispensing line (Fig. 2) comprises such elements:
1-beer kegs; 2-pytlion; 3-- heat exchange unit of cooler LCB-200D POLAR, 4-
dispenser;
5 - water condenser of cooler LCB-200D POLAR; 6- water regulating valve (WRV);
7-
propylene glycol pump; 8- propylene glycol vessel of cooler LCB-200G POLAR; 9-
soldered plate heat exchanger of cooler LCB-200G POLAR; 10 - air condenser of
cooler
LCB-200G POLAR.
Cooler LCB-200G POLAR refrigerates propylene glycol in the following way.
Propylene glycol precooled at heat excllanger 9 due to pressure difference
developed by pump
7 is fed to vessel 8. Then the same pump 7 pumps propylene glycol from vessel
8 to pytllon
hose 2. From python 2 propylene glycol passes through a tee to heat exchange
unit 3 and from
thence is recycled to be cooled at heat exchanger 9. Cooling at heat exchanger
9 is performed
by refrigerating machine being a part of cooler LCB-200G POLAR.
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Propylene glycol while cycling around the system serves several purposes.
First of all,
it maintains the temperature of beer fed via python hose 2. Beer is fed from
kegs I at
temperature 4.5 C to reach python liose 2. To the same hose propylene glycol
is fed as cooled
at heat exchanger 9 to temperature -3 C. Accordingly, due to heat exchange
between low
temperature propylene glycol and warmer beer the temperature of beer is
maintained
throughout its passage through the python liose. Thus, beer temperature at the
exit of python
hose 2 will be equal or lower than at the entrance. If beer temperature at
python entrance is
4.5 C, it should not exceed this value at the exit. This is attained by triple
circulation of
propylene glycol along the hose, i.e., propylene glycol passes within the
python hose three
times, which ensures that the beer would not be heated in the hose. To this
end the python
hose with total length of 40 m coinprises three 40-m propylene glycol lines
connected in
series, thus, the total propylene glycol path in the python hose makes 120 m.
Propylene glycol also cools water condenser 5 of refrigerating machine LCB-
200D
POLAR.
Stable cooling of water condenser depends not only of the temperature of
propylene
glycol but of its consumption as well. Lesser quantity of propylene glycol
means insufficient
cooling of the condenser, whereas propylene glycol overconsumption leads to
its excessive
cooling. Both options are unfavorable for cooler operation. Propylene glycol
consumption
depends primarily on python hose length. Larger length means smaller
consumption, reduced
length increases consumption. To ensure stable propylene glycol consumption
through water
condenser, a water-regulating valve is installed at the entrance of water
condenser. The
appearance of water regulating valve (WRV) is shown in Fig.2.
Cooler LCB - 200D POLAR serves for deep refrigeration of beer up to the
temperature
-5 C at heat exchange unit 3 before dispensing at dispenser 4. Cooler LCB -
200D POLAR is
a dry aluminum block-type apparatus. Beer from kegs I is fed at temperature
4.5 C to python
hose 2. Then from python hose 2 beer at the same teinperature 4.5 C is fed to
heat exchange
unit 3 where it is additionally cooled to -5 C, and thence it is fed to
dispenser 3 for dispensing
into vials. Propylene glycol while passing through heat exchange unit 3
prevents its
overfreezing at resuming mode when beer is not dispensed.
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Water condenser permits to avoid dependence on ambient temperature. This
element is
cooled with water or aqueous solution of propylene glycol as in the proposed
scheme. The
temperature of propylene glycol fed to condenser is actually identical both in
summer and in
winter. Accordingly, condenser operation does not depend on ambient
temperature, it is
determined by the temperature of propylene glycol at condenser entrance, which
in turn is
maintained constant by a separate cooler LCB - 2000G POLAR. Thermal load on
aluminum
heat exchange unit remains actually unchanged, as beer throughput is constant
under all
operation modes of the line. Thus, the proposed solution enables a stable
cooling cycle and,
tlius, stable freezing capacity of cooler.
Stable cooling of water condenser depends not only on temperature of propylene
glycol
at condenser entrance, but on its flow rate as well. At lesser propylene
glycol flow rate
condenser cooling would be inadequate, whereas increased flow leads to
overfreezing. Both
extreme cases are unfavorable for cooler operation. Therefore, it the proposed
solution
propylene glycol flow rate depends mainly on optimal length of python hose.
With this length
above optimal value the flow would reduce, a shorter length increases the flow
rate. To ensure
optimal flow rate of propylene glycol through water condenser water regulating
valve (WRV)
is installed at condenser entrance. Necessary propylene glycol flow rate may
be established
manually at water regulating valve and then nlaintained in automatic fashion.
In the proposed
solution the length of python hose should be at least 40 m. This is an average
or the most
widely met distance between dispenser tap and beer keg storage chamber,
established in
experimental way. In case python hose length turns to exceed 40 m, such a
change would
necessitate correction of the set propylene glycol flow rate, which
deteriorates operation of the
entire line. Water regulating valve serves just for similar situations. With
line installation
finished it would be necessary to adjust water-regulating valve to the
parameters specified in
operation manual, and then this value would be maintained automatically.
The temperature of diy aluminunl unit as maintained by LCB - 200D POLAR cooler
lies within the range -5 C to -1.5 C, thus ensuring reliable product cooling
to temperatures
below zero. While the temperature remains in this range, the cooler is in
holding mode and its
compressor does not activate. Water regulating valve 6 is completely closed,
propylene glycol
is fed to be cooled at heat exchanger 9 via lleat exchange unit 3. Then, with
beer fed to
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CA 02637861 2008-07-09
cooling, the temperature of aluminum heat exchange unit 3 rises, and when it
reaches -1.5 C
compressor is activated, thus reducing temperattire of the unit, water
regulating valve 6 opens
automatically and feed of propylene glycol to cool condenser 5 begins. Later
on it is mixed
with the main stream of propylene glycol to be cooled at heat exchanger 9.
As evident from the above, the proposed solution has distinct differences from
the
existing lines with propylene glycol as cooling medium. Traditional cooling
lines do not
comprise units for maintenance of stable product temperature below zero at
maximum
throughput of 212 L/hr. The length of python hose therein strictly limits the
operation of
propylene glycol coolers. The proposed keg beer cooling and dispensing line
permits variation
of length of python hose and, respectively, acljustment of the entire line
issuing propylene
glycol from conditions at a particular facility. The proposed propylene glycol
circulation pump
is selected in confonnity with final length of python hose depending on the
distance between
dispenser and beer keg storage chamber, irrespective of prescribed of fixed
length of python
hose as in traditional cooling lines.
Traditional propylene glycol coolers in beer cooling lines have a standard
design:
propylene glycol aqueous soltition is poured into a bath and cooled by
refrigerating machine,
its evaporator being submerged into the tub filled witli propylene glycol.
LCB - 200G POLAR cooler (Figs.3-8) to cool propylene glycol in the proposed
beer
cooling line does not have such a tub. Propylene glycol is cooled in a
soldered plate heat
exchanger, unlike traditional designs. This is due to large freezing capacity
of our supposed
LCB - 200G POLAR cooler.
To ensure product cooling to teulperatures below zero (5 C to -1.5 C) the
proposed
LCB - 200G POLAR cooler has fi=eezing capacity 2,6 to 3 kW depending on
operational
mode. This is equivalent to thernial capacity of a long-term food storage
chamber with volume
12...16 m3 at a small grocery or 10 high-class domestic refrigerators, 300 W
each. Therefore,
in order to reach such a capacity we propose to apply a soldered plate heat
exchanger as an
evaporator of refrigerating machine. We suppose this type of heat exchanger to
be the most
efficient of all commercially available nowadays. The main advantage of such
heat exchangers
lies in excellent tliermal characteristics, higli thermal capacity and very
efficient heat exchange
design.
CA 02637861 2008-07-09
The heat exchanger is a set of plates made of stainless steel and connected
with copper
solder. Each plate has its own texture of cllannels where the media flow,
their totality forming
the heat exchange surface.
Such heat exchangers are not usual in traditional propylene glycol coolers of
beer
cooling lines that are too weak for such amounts of pumped product. Variation
of python hose
length leads to some change in propylene glycol consumption. Thus, thermal
load varies on
the evaporator of refrigerating machine LCB-200G POLAR, i.e., soldered heat
exchanger. To
cope with varying thermal load we must maintain the appropriate amount of
freon fed to
soldered heat exchanger to cool propylene glycol. To this end cooler LCB-200G
POLAR has a
tliermal regulating valve. This valve seives for optimal filling of evaporator
with Freon
depending on its thermal load. In niost cases such coolers are equipped with
permanent-
section capillary pipes. But due to permanent section of the pipe the amount
of Freon fed to
the evaporator is also pernianent. In the thermal regulating valve the flow
section varies in
accordance with thermal load of evaporator, thus ensuring optimal filling of
evaporator with
Freon. Filling of evaporator witli freon is regulated by tliermal regulating
valve in an
automatic fashion. The valve may be adjusted manually, if necessary.
Besides, the proposed keg beer cooling and dispensing line is independent from
fixed
distances between bar stand and beer keg storage chanlber, thus permitting to
suppress or
minimize excessive heat flows around the bar stand; it may be adjusted for
particular facility
conditions and then operate in a fiilly automatic fashion.
Both coolers in beer cooling line may be automatically disconnected in case of
emergency. To this end, the coolers are equipped with cartridge-type pressure
regulators or
high and low side pressure relays. If the feed of propylene glycol to water
condenser of LCB -
200D POLAR cooler (failure of propylene glycol pump or propylene glycol leak
in the line)
the cooler high side pressure relay would activate. Cooling of water condenser
would stop
without incoming propylene glycol, coiisequently, pressure would rise in
pressure line of
cooler refrigeration loop, and accordingly pressure relay disconnects the
cooler. Pressure relay
has a manual reset button, therefore, the cooler may not activate until the
failure in propylene
glycol loop is removed. Only when the line becomes operable again, manual
reset button
activates the cooler. In case prohylene glycol feed to refrigerating
evaporator serving to cool
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CA 02637861 2008-07-09
propylene glycol at LCB - 200G POLAR is stopped, thermal load on the
evaporator drastically
reduces and the pressure in evaporator refrigerating loop begins failing. Then
low side
pressure relay would disconnect the cooler. It is equipped with a manual reset
button as well
as the high side pressure relay. Thus, oiily after the failure is removed
cooler may be activated.
All emergency disconnections of coolers forniing beer-cooling line are
performed in automatic
mode. Miniinum time between failures is established as at least 5 000 hours
for each cooler.
Mean time between failures is establisliecl as at least 10 000 hours for each
cooler. Total
minimum service life for each cooler is 10 years witli the proviso of adequate
maintenance.
Average repair time is 3.5 hours for each cooler (if manufacture of new units
is not necessary).
As evident from the description of the device it is new and may be widely used
for
equipment of cafes, bars and restaurants that dispense keg beer.
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