QUICK ICE MAKING UNIT
Field of the Invention
This invention relates to an ice making unit. More specifically, the present invention relates to a
quick ice making unit which can be incorporated in existing refrigerators.
Background
Almost every house has a refrigerator today. Size of the refrigerator may vary based on the
financial conditions of the individuals, but, majority of the people have refrigerators at home. It
has become the most essential house hold product.
As it is very evident, refrigerators are devised for storing and cooling items, precisely food items
for preserving from decaying for a longer time. Almost all types of food items can be stored and
preserved i.e. solid, semi-solid and liquid. Apart from storing, cooling & preserving, the
refrigeratorscan also be used for freezing certain items such as liquids.
During summers the refrigerators are being utilized to the maximum. Especially, people prefer
drinking cold water or juice in the summers to get rid of heat/ get a respite. Accordingly,
consumption of cold water/juices is very high.
More importantly, during summers refrigerators are used to form ice cubes by freezing the water
placed in an ice container.
Unfortunately, refrigerator takes a long time to form/make ice cubes. Since, people have to wait
to get ice cubes, they have to consume the ice cubes cautiously. Otherwise, they have to again
wait for the refrigerator to make ice.
Consequently, there is a need to quicken up the process of making/forming ice.
In order to overcome this issue, there are many conventional refrigerators which consist of a
separate freezing compartment. The freezing compartment employs an ice making unit to
convert water into ice. Unfortunately, as shown in figure 1, such conventionally available
refrigerators takes more than 100 minutes to make ice which is too long time and undesirable.
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There are further refrigerating systems in art which tries to resolve the issue of quick ice making.
However, one such system requires a further separate compartment within the freezing
compartment. Such system utilizes additional components and requires a complete change in the
entire refrigerator body. In addition, such refrigerators utilizes additional components i.e. an
assembly of an extra fan, separator, motor and thermoelectric elements. In this system an ice
container is filled with water and placed onto ice-making unit. The said system providers an
insulated outer surfaces, which are located in the freezing compartment. High-flow cold air
fluxes are achieved in the ice-making units of the invention equipped with thermoelectric cooler
and/or cold air blower thereby water in the ice container is solidified.
Another system described in prior art comprises of a fan and a compressor for enabling the quick
ice-making option. Air cooled by an evaporator is transferred into a freezer with the aid of a fan,
thereby enabling the ice container to be cooled. Air heated as a result of a heat transfer occurred
in the freezer section is vented out and re-cooled, and then it is sent back to the freezer section.
However, homogenous cooling of the ice container cannot be achieved in this system.
Yet another system describes a quick ice-making control mechanism. Water is filled into a
semicircular ice container and cooled with the aid of an evaporator. A mixer is used to accelerate
the heat exchange between water and cold air within the ice container. Ice formation is achieved
by the heat transfer occurring with the aid of the mixer. An ice container is provided with a
heater at its outer side to remove ice there from.
As shown in table below, conventionally available ice making units/refrigerators take more than
100 minutes to make ice which is undesirable:
Desc 242L 262L 340L 360L 255L 315L 240L 320L
ICM
Tray
@43o C
100 min 105 min 106 min 108 min 126 min 178 min 154 min 152 min
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As it can be noticed, all the conventional system requires a separate assembly/ separate
compartment requiring of several additional components to speeding up the formation of ice, but
still takes undesirably 100 minutes to form ice. Hence, all the above mentioned systems requires
lots of changes in the existing freezing compartment and also requires a lot of space and still
cannot quicken the formation of ice in a desirably less time. Therefore, these systems are
expensive, ineffective and complicated in construction.
The limitations and disadvantages of conventional and traditional approaches of making quick
ice are apparent to one of skill in the art, Hence, there exists a strong need to provide a quick ice
making unit/assembly which can provide ice in a desirably less time that are effective, cost
efficient and at the same time, simple to implement.
Object of the Invention
Primary objective of the present invention is to provide/make ice in a desirably less time.
Another object of the present invention is to provide a quick ice making unit/device/assembly to
provide/make ice in a desirably less time.
Yet another object of the present invention is to provide a quick ice making unit/device/assembly
to provide/make ice in a desirably less time that are effective, cost efficient and at the same time,
simple to implement.
Further object of the present invention is to provide a quick ice making unit to quickly freeze
water in ice container using air circulation in an existing freezing compartment.
Furthermore object of the present invention is to enable these units to be utilized in currently
available refrigerators.
Another object of the present invention is to enable this unit to be utilized in currently available
refrigerators with least change in current freezing compartment.
Yet another object of the present invention is to provide ice less than or equal to 25 minutes.
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Summary of the Invention
Accordingly the present invention relates to a quick ice making unit/assembly/arrangement,
comprising: an ice container made of a material having high thermal conductivity to freeze the
water contained therein faster; a holder/stand for holding/supporting the ice container; plurality
of groves/channels formed at the bottom of the ice container to allow passing of cold air within
the said grooves and retain the cold air within the said grooves for ensuring longer contact of
cold air with the water; and at least one deflector being attached to the air vent and located at one
of the walls of the cooling chamber for creating turbulent flow of cool air; the said ice container
being placed at a predetermined distance below or above the said at least one deflector in order
to receive the maximum cold air through forced air circulation to the top and bottom of the ice
container to freeze water in the container quickly and convert it into ice.
According to another aspect of the present invention, wherein the ice container is located in the
highest air velocity region.
According to yet another aspect of the present invention, wherein the ice container is made of
metal.
According to further aspect of the present invention, wherein the ice container is made of
aluminum-silicon alloy or similar alloys.
According to furthermore aspect of the present invention, wherein the ice container is made of
combination of metal and plastic.
According to another aspect of the present invention, wherein the ice container is made of
plastic.
According to yet another aspect of the present invention, wherein the ice container comprises
plurality of slots for holding water/ice.
According to further another aspect of the present invention, wherein the thickness of the ice
container ranges between 0.5mm- 2mm.
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According to furthermore aspect of the present invention, wherein number of holding slots varies
from 6 to 8.
According to another aspect of the present invention, wherein the ice container is provided with a
protection barrier against corrosion of the metallic tray.
According to yet another aspect of the present invention, wherein surface of the metallic tray is
scratch resistant.
According to further aspect of the present invention, wherein length of the grooves is in the
range of 1mm - 5 mm.
According to furthermore aspect of the present invention, wherein the grooves make velocity
distribution uniform below the ice container.
According to another aspect of the present invention, wherein the height of the slot of the
container is 12 mm-18mm.
According to yet another aspect of the present invention, wherein the shape of the slot is
rectangular.
According to further aspect of the present invention, wherein the shape of the slot is trapezoidal.
According to furthermore aspect of the present invention, wherein the volume of the ice
container ranges from 50-85ml.
According to another aspect of the present invention, wherein the holder comprises of two
separate stands/legs spaced apart and fixed to one of the walls of the refrigerator.
In the above paragraphs the more important features of the invention has been outlined, in order
that the detailed description thereof that follows may be better understood and in order that the
present contribution to the art may be better understood and in order that the present contribution
to the art may be better appreciated. There are, of course, additional features of the invention that
will be described hereinafter and which will form the subject of the claims appended hereto.
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Those skilled in the art will appreciate that the conception upon which this disclosure is based
may readily be utilized as a basis for the designing of other structures for carrying out the several
purposes of the invention. It is important therefore that the claims be regarded as including such
equivalent constructions as do not depart from the spirit and scope of the invention.
The following paragraphs are provided in order to describe the best mode of working the
invention and nothing in this section should be taken as a limitation of the claims.
Brief description of the drawings
Further aspects and advantages of the present invention will be readily understood from the
following detailed description with reference to the accompanying drawings. Reference numerals
have been used to refer to identical or similar functionally similar elements. The figures together
with a detailed description below, are incorporated in and form part of the specification, and
serve to further illustrate the embodiments or aspects and explain various principles and
advantages, in accordance with the present invention wherein:
Fig. 1 shows the time taken by conventionally available ice units to make ice.
Fig. 2(a) & 2(b) show the location of the ice container in freezing compartment according to an
aspect of the present invention.
Fig. 3 shows the solidification process of water in a freezing compartment according to an aspect
of the present invention.
Fig. 4(a) shows the position of deflector in freezing compartment according to an aspect of the
present invention.
Fig. 4(b) shows the various components associated with flow of air according to an aspect of the
present invention.
Fig. 5(a)5(b), 5(C) & 5(D) show the design of the ice container according to an aspect of the
present invention.
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Fig. 6 shows the effect of grooves on the velocity distribution below the ice container according
to an aspect of the present invention.
Fig. 7 shows the graph between length of the grooves and heat rejection through the groove
according to an aspect of the present invention.
Fig 8(a) & 8(b) show the air flow pattern in ice container region in freezing compartment
according to an aspect of the present invention.
Fig. 9 shows reduction in time for sensible heat & latent heat exchange according to an aspect of
the present invention.
Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity
and have not necessarily been drawn to scale. For example, the dimensions of some of the
elements in the drawings may be exaggerated relative to other elements to help to improve
understanding of embodiments of the present invention.
Detailed description of the invention
In order that the invention may be readily understood and put into practical effect, reference will
now be made to exemplary embodiments as illustrated with reference to the accompanying
drawings, where like reference numerals refer to identical or functionally similar elements
throughout the separate views. The figures together with a detailed description below, are
incorporated in and form part of the specification, and serve to further illustrate the embodiments
and explain various principles and advantages, in accordance with the present invention where:
The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a
non-exclusive inclusion, such that a process, method that comprises a list of steps does not
include only those steps but may include other steps not expressly listed or inherent to such
process, method. Similarly, one or more elements in a system or apparatus proceeded by
“comprises… a” does not, without more constraints, preclude the existence of other elements or
additional elements in the system or apparatus.
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The present invention relates to a quick ice making unit/assembly. The unit comprises of an ice
container having high thermal conductivity, made of aluminum-silicon alloy or similar alloys, at
least one deflector and a holder to hold the ice container. The ice container comprises plurality of
holding slots to contain water to be cooled and grooves at the bottom of the ice container. The
ice container is placed at a predetermined distance in the high velocity region in freezing
compartment. The deflector is placed near the openings of air vent in the ice container. The
assembly increases the velocity of air in the ice container region and provides improved air flow
pattern within the region. The grooves make velocity distribution uniform below the ice
container.
Figure 1 represents an overview of ice making unit according to one embodiment of the present
invention. The ice unit comprises of an ice container, a holder and at least one deflector. The ice
container contains water to be cooled, wherein said ice container consists of plurality of holding
slots to hold water and grooves at the bottom of the ice container. The thickness of the container
not limited to ranges between 0.5 mm- 2mm and volume of the ice container not limited to
ranges between 50ml-85ml. The length of the grooves not limited to ranges between 1mm-5mm.
The ice container is made of a material having high thermal conductivity. The ice container can
be made by not limited to (1) Metal (2) Combination of metal (aluminum, aluminum-silicon
alloy or similar high conductivity alloys) and plastic and (3) Plastic.
The ice container is placed at a predetermined distance from the openings of the air vent in the
freezing compartment. The freezing compartment are available in the existing refrigerators. The
ice making units of the present invention are implemented in the existing freezing compartments.
However, the present invention can also be implemented in refrigerators which do not contain
separate freezing compartments. It can also be appreciated by the skilled person in the art that a
freezing compartment can also be customized for the ice making unit of the present invention.
The ice container is located in the high velocity region in order to expose the ice container to the
cold air. Precisely, the container is located at a predetermined distance above or below the
deflector to receive maximum cold air encircling the container to freeze water and convert it into
ice through forced air circulation to the top and bottom of the ice container. A holder/stand is
provided to hold the container. The stand/holder are distanced apart and fixed to the wall of the
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refrigerator. The at least one deflector is placed near the openings of the air vent. Deflector
increases the Reynolds number which in turn increases overall heat transfer coefficient and this
result in reduction in ice making time. The grooves provided at the bottom of the ice container
make velocity distribution uniform below the ice container which causes water to freeze quickly.
The ice container is provided with a protection barrier against corrosion and has a scratch
resistant surface. In this way, the present unit provides ice in 20 and 24 min at 32 and 43°C.
The present invention provides a quick ice making unit which can be added to existing
refrigerator with minor changes in freezing compartment. As it can be noticed from the
background section, conventional ice making time ranges from 80 – 160 mins . at 32 and 43°C
respectively while the ice unit of the present invention reduces ice making time to 20 and 24 min
at 32 and 43°C respectively.
The critical factors for quick ice formation include i) Velocity, volume of air low and location ii)
Ice tray design iii) Material & manufacturing process selection. The quick ice making unit of the
present invention has been designed considering all these parameters. According to an aspect of
the present invention, the unit uses the forced air flow occurring in freezing compartment to
shorten the time of making ice. Further, the ice container comprises of plurality of holders to
contain water to be freeze.
Fig. 2(a) shows the location of the ice container in freezing compartment according to an aspect
of the present invention. As shown in the figure, the ice container is located near the openings of
the air vent in freezing compartment where velocity of air is maximum. Fig. 2(b) shows the
velocity of air near different air vents and highest velocity region is identified above the ice
container. The ice container is added in the highest velocity region without any change in current
space management.
Fig. 3 shows the solidification process of water in a freezing compartment. Solidification starts
from top, bottom & sides of the cube to the center.
Overall thermal Resistance of the ice tray can be defined as:
1/(U.A) = 1/(h1.A1) + dxw/(k.A) + 1/(h2.A2)
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Where,
U = the overall heat transfer coefficient
A = the contact area for each fluid side (with A1 & A2 expressing either surface)
k = the thermal conductivity of the material
h = the top and boom of the convection heat transfer coefficient or each fluid
dxw = the wall thickness
h1.A1 is heat transfer above the ice container which depends on ice/air heat transfer coefficient.
k.A is heat transfer through material and to reduce the resistance, the material of ice container
should have high thermal conductivity.
h2.A2 is heat transfer below the ice container which depends on the surface area.
Fig. 4(a) shows the position of deflector in freezing compartment. The deflector is added near the
openings of air vent above and/or below the ice container.
Fig. 4(b) shows the various components associated with flow of air. In fig. 4(b),
v1 = Air Flow Velocity in the plenum and v2 = Air Flow at the opening point of plenum slot,
p1 is the pressure inside the plenum and p2 is the pressure at the opening point
z is the elevation of the point above a reference plane, with the positive z-direction pointing
upward – so in the direction opposite to the gravitational acceleration,
g is the acceleration due to gravity.
ρ is the density of the fluid at all points in the fluid.
According to Bernoulli’s principle, the total sum of pressure head, velocity head and datum head
remains constant during the fluid flow if flow losses are assumed negligible. It can be defined as:
This means, an increase in the speed of the fluid occurs proportionately with a decrease in its
static pressure and potential energy. Bernoulli's principle is applicable for only in viscid flows.
Bernoulli’s principle states that:
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And it is known that
Where, m = mass flow rate
So due to presence of the deflector pressure head at the openings slots decreases and velocity
head increases so mass flow at inlet & Outlet is Constant. So, Convective heat transfer
coefficient (h) will improve.
Renolyds number (Re) is degrooveed as
Where,
v is mean velocity of the object relative to the fluid ( m/s)
L is a characteristic linear dimension, (travelled length of the fluid)
μ is the dynamic viscosity of the fluid (Pa·s or N·s/m² or kg/(m·s))
is the kinematic viscosity ( μ / ρ ) (m²/s)
ρ is the density of the fluid (kg/m³).
Since, due to reflector velocity head increases, Renolyds number is also increased which causes
Turbulent flow of air. Renolyds Number (Re) with deflector at freezing compartment top slots is
22478.
For turbulence flow the Nusselt Number (Nu) or flow over lat plate can be defined as:
Nu=0.664* (Re^0.5) * (Pr^(1/3))
Increase in Re causes increase in Nu which causes increase in Convective heat transfer
coefficient (h), since Nu & h are related as:
h = Nu* k/L
this in turn increases overall heat transfer coefficient (U), since h & U are related as:
m = ρAV .
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Fig. 5(a), 5(b), 5(C) and 5(d) show design of the ice container. The ice container consists of
holing slots to contain water, which are trapezoidal in shape and grooves at its bottom. The shape
of holding slots may be rectangular also. Trapezoidal shaped ice cubes are easy to release from
ice container. Number of holding slots may vary from 6 to 8. The volume of ice container is in
the range of 50-85 ml. The ice container is made of aluminum-silicon alloy or similar alloys.
Thickness of the ice container ranges between 0.5 mm- 2mm. The grooves below the ice
container increases the surface area which in turn increases the heat transfer coefficient at bottom
of the ice container, which decreases time for making ice. The manufacturing process used for
the ice container is high pressure die casting which requires good fluidity at lower temperature,
which is achieved by the use of silicon. Anodizing, Teflon, Epoxy or similar coatings can be
used. The ice container is provided with a protection barrier against corrosion. The surface of the
ice container is scratch resistant.
Fig. 6 shows the effect of grooves on the velocity distribution below the ice container. Grooves
at the bottom of the ice container make velocity distribution more uniform below the ice
container.
Fig. 7 shows the graph between length of the grooves and heat rejection through the grooves.
The length of the grooves is kept from 1mm-5mm because beyond that grooves do not contribute
to heat transfer since grooves are at the temperature of the environment.
Fig 8(a) & 8(b) show the air flow pattern in ice container region in freezing compartment. Fig.
8(a) shows air flow pattern before modification in freezing compartment and fig. 8(b) shows air
flow pattern after modification in freezing compartment. It is clear from the figures that after the
modifications made in the position of the ice container in the freezing compartment, air flow in
the ice container region in the freezing compartment is highly improved and the velocity of air in
the region is increased. This modification in freezing compartment decreases the time of making
ice and provides ice quickly.
Fig. 9 shows reduction in time for sensible heat & latent heat exchange with quick ice making
unit. This reduction in time shortens the time for making ice.
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The disclosed invention is thus attained in an economical, practical, and facile manner. It is to be
understood that various further modifications and additional configurations will be apparent to
those skilled in the art. It is intended that the specific embodiments, configurations and
calculations herein disclosed are illustrative and should not be interpreted as limitations on the
scope of the invention.
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We Claim:
1. A quick ice making unit, comprising:
an ice container made of a material having high thermal conductivity to freeze the
water contained therein faster;
a holder/stand for holding/supporting the ice container;
plurality of groves/channels formed at the bottom of the ice container to allow
passing of cold air within the said grooves and ensuring longer contact of cold air with
the water; and
at least one deflector being attached to the air vent and located at any one of the
walls of the cooling chamber for creating turbulent flow of cool air;
the said ice container being placed at a predetermined distance below or above the
said at least one deflector in order to receive the maximum cold air through forced air
circulation to the top and bottom of the ice container to freeze water in the container
quickly and convert it into ice.
2. The unit as claimed in claim 1, wherein the ice container is located in the highest air
velocity region.
3. The unit as claimed in claim 1, wherein the ice container is made of metal.
4. The unit as claimed in claim 1, wherein the ice container is made of aluminum-silicon
alloy or similar alloys.
5. The unit as claimed in claim 1, wherein the ice container is made of combination of metal
and plastic.
6. The unit as claimed in claim 1, wherein the ice container is made of plastic.
7. The unit as claimed in claim 1, wherein the ice container comprises plurality of slots for
holding water/ice.
8. The unit as claimed in claim 5, wherein the thickness of the ice container ranges between
0.5mm- 2mm.
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9. The unit as claimed in claim 5, wherein number of holding slots varies from 6 to 8.
10. The unit as claimed in claim 1 wherein the ice container is provided with a protection
barrier against corrosion of the metallic tray.
11. The unit as claimed in claim 1, wherein surface of the metallic tray is scratch resistant.
12. The unit as claimed in claim 1, wherein length of the grooves is in the range of 1mm - 5
mm.
13. The unit as claimed in claim 1, wherein the grooves make velocity distribution uniform
below the ice container.
14. The unit as claimed in claim 5, wherein the height of the slot of the container is 12 mm-
18mm.
15. The unit as claimed in claim 5, wherein the shape of the slot is rectangular.
16. The unit as claimed in claim 5, wherein the shape of the slot is trapezoidal.
17. The unit as claimed in claim 5, wherein the volume of the ice container ranges from 50-
85ml.
18. The unit as claimed in claim1, wherein the holder comprises of two separate stands/legs
spaced apart and fixed to one of the walls of the refrigerator.