Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02516148 2005-08-17
METHOD AND APPARATUS FOR CHILLING BEVERAGES WITH PHASE
CHANGE MATERIALS
Field of the Invention
This invention relates in general to dispensing cold beverages from a tap, and
in
particular to a device that enhances the cooling capacity of establishment
wide beer
dispensing systems such as typically found in bars and the like.
Description of Prior Art
Draught beverages in restaurants, bars, stadiums and other facilities are
dispensed
using systems that consist of a storage container that is kept cool in a
remote
1o refrigerator, a supply line that takes the beverage to the dispensing
faucet and a
dispensing faucet. Generally the beverages are stored in containers that are
kept in
remote walk-in refrigerators. Drinks may be dispensed at a location several
hundred
feet away from the storage container. The beverage trunk line used to
transport the
beverage to the dispensing tap is generally made up of a mufti-line insulated
15 construction that contains two central cooling liquid lines that will bring
a cold
glycol/water mixture, refrigerant or ice water to the tap and back to maintain
the
beverage's temperature.
While this system is generally successful, it is inconsistent. The
temperatures inside
walk-in coolers fluctuate widely or are not regulated to the ideal serving
temperature.
2o The beverage trunk line will travel through areas of varying ambient
temperatures and
will often expose the beverage to hot spots that will raise the beverage
temperature.
To solve this problem heat exchangers have been added to the trunk line or at
the tap
to give the beer a final chill. The final chilling of the beer with these heat
exchangers
and the existence of hot spots warms the glycol, refrigerant or cold water and
25 overburdens the refrigerating device that is used to chill the glycol,
refrigerant or cold
water and the coolant becomes warm. Liquid coolants have a low specific heat
in the
range of 1 btu/ degF/lb and will warm rapidly during pour times. Once the
coolant is
warm it takes time for it to cool down to the desired temperature. Beer poured
during
this time becomes too warm to be served. Coolant sources operate 24 hours a
day
CA 02516148 2005-08-17
while beverage is usually served 16 hours per day. Further , beverages are
ususlally
poured intermittently, which allows for some recovery time. However, due to
the low
specific heat of the coolants in use, a low amount of cooling capacity is
stored.
Summary of the Invention
According to one aspect of the invention a beverage distribution system is
provided.
The system includes a beverage source; at least one beverage dispensing unit;
a
supply of coolant, at least one distribution line for delivering beverage and
coolant
from the beverage source to the dispensing unit; and a heat transfer unit
located
distally from the beverage source for transferring heat from the beer to the
coolant.
1o The coolant returns back to the coolant supply through the distribution
line. The heat
transfer unit counteracts the warming of the beverage, such as beer, that
arises as a
result of routing the beverage distribution lines over long distances or
through warm
environments. A container filled with eutectic or phase change material is
submerged
in a tank which is located in the distribution line. Coolant is routed from
the coolant
return line inside the distribution line and into the tank where it freezes
the eutectic
material during times when beverage is not being poured. The eutectic material
is
designed to freeze at a point equal to or slightly above the desired
temperature of the
coolant. During times when the beverage is being poured, the return coolant
will be
warmed. The energy absorbed by the eutectic material during the freezing
process is
now available to the coolant and the warmed coolant is cooled without
overburdening
the refrigeration system.
In a second aspect of the invention, a container filled with eutectic material
is
submerged inside the glycol deck tank along with the refrigeration evaporation
coil.
The eutectic material will freeze during the nighttime and other non-pouring
times.
The energy required to solidify the eutectic material (heat of fusion) will be
stored and
be available to cool the coolant during busy pouring times.
In a third aspect of the invention, a reservoir of eutectic material may be
incorporated
with a heat exchange device heat transfer unit located distally from the
beverage
source for transferring heat from the beer to the coolant. The eutectic
material inside
2
CA 02516148 2005-08-17
the reservoir will freeze during nonpouring times and be available to chill
the coolant
during periods of heavy use.
Brief Description of the Drawings
In drawings which illustrate by way of example only a preferred embodiment of
the
invention,
Fig 1 is a schematic illustrating a beverage dispensing cooling system
constructed in
accordance with this invention
Fig 2 is a schematic illustrating a beverage dispensing cooling system
constructed in
accordance with a second aspect of this invention
1o Fig. 3 is a schematic illustrating a beverage dispensing cooling system
constructed in
accordance with a third aspect of this invention
Fig 4 is a cross-sectional view of the preferred embodiment of the invention
Fig. 5 is a cross-sectional view of a second aspect of this invention
Fig 6 is a cross sectional view of a third aspect of this invention
Detailed Description of the Invention
Fig 1 shows a beverage dispenser cooling system particularly for use in
dispensing
beer on tap. The system includes a storage container such as a beer keg 31
containing
beer. The keg 31 will typically be located within a refrigerated unit 33 such
as a large
walk-in refrigerator. A pressurized tank, usually containing carbon dioxide,
beer gas
or compressed air 39 is connected by line 35 to the interior of keg 31 for
applying
pressure to the beer therein. The contents of the beer keg 31 are cormected to
the
dispensing tap 36 by line 11 that travels through an insulated trunk line 34.
The
distance between the beer keg 31 and the dispensing tap 36 can be quite far,
with the
trunk line extending up to five hundred feet. To prevent the beer in the trunk
line
from warming excessively, a glycol unit 32 is used. Glycol unit 32 is a
conventional
assembly, which chills glycol and pumps it through the trunk line 34 to the
dispensing
3
CA 02516148 2005-08-17
tower 37 and back. The glycol travels in parallel with the beer keeping it
cool. The
glycol will increase in temperature as it travels to the tower 37 and back.
The
temperature will rise higher if a booster is placed in-line with the trunk
line. Figure 2
shows a cooling booster 60 that is placed in the trunk line 34 between the
glycol deck
32 and the dispensing tap 36 to extend the cooling capacity of the glycol deck
32.
The coolant booster 60 has a coolant inlet 57, which allows the coolant to
flow
through the void 42 and exit through passageway 50. The coolant flows over a
submerged tank 46, which is filled with a eutectic or phase change material
that is
designed to freeze at a temperature just above the preferred coolant
temperature. A
1o passageway 47 allows for eutectic material to be poured into the tank 46.
The
passageway 47 is capped by cap 61.
In a second aspect of the invention, the beverage booster is integrated with
the coolant
booster into a combined booster 79 as shown in Figure 5. The combined booster
is
comprised of an outer shell 76 covered in an insulating material 77 and an
outer shell
75 with end caps 73 and 91. Glycol will enter through port 94 and exit through
port
72. Beer will enter through port 95 and exit through port 70. The beer will
flow
through a coil heat exchanger that is spaced radially from the eutectic
material tank
74. Eutectic material enters through port 71 and is capped by cap 96.
Eutectic material may also be placed in the glycol deck tank 87 as shown in
figure 6.
2o Glycol from tank is extracted through port 84 into pump 85 and sent through
portal 86
to the trunk Bone 34. Glycol returns from the trunk line 34 and re-enters the
glycol
tank 87 through port 14. a single or multiple number of containers 88 filled
with
eutectic material is or are placed in the glycol tank 87 so as to impart
stored cold to
the glycol in the tank 87.
4
