Note: Descriptions are shown in the official language in which they were submitted.
-~` 133~287
"ICE MAKING APPARATUS"
The present invention relates to ice making
apparatus. In particular, the invention is directed to a
machine for making flake ice.
BACKCROUND OF THE INVENTION
Flake ice is made in this sheets approximately 1.5-
6.0 mm thick. ~he sheets may be aurved or flat and the thin
ice is generally broken into random-sized flakes when
harveæted.
Flake ice is particularly suitable for paaking
products such as fish or frozen foods as the iC8 flakes can
be packed close to the products. In other applications such
as chemical processing and conorete cooling, where rapid
cooling is important, flake ice is ideal because the flakes
present the maximum amount of cooling surface for a given
amount of ice.
Flake ice is commonly produced by the application
of water to the inside or outside of a refrigerated
cylindrical drum. The water ls applied at a first angular
location on the drum and adhere~ thereto in a thin layer by
surface tension. AB the drum rotates, the water freezes lnto
a thin layer of ice, which i6 fraatured by an ice removal
device at a second angular location downstream from the first
angular looation in the dir~ction of rotation.
The thickness of the flake ice can be varied by
~adjusting the speed of the rotating drum, varying the
evaporator temperature, and regulating the water flow on to
the fre~ezing surfaae. Sinae flake ice can be made in a
continuous operation without being interrupted for a harvest
cyale, less refrigeration tonnage is required to produce a
tonne of ioe than any other type of manufactured ice when
slmilar make up~water and evaporating temperatures are
compared.
In known maahines, water i8 applied to only one
side of the drum, i.e. either the outside or inside, but not
both. As a result, the refrigerated surface on the other
side of the drum is unused, and the ice making operation
represents an inefficient use of the refrigeration aapacity
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2 133128 ~
of the machine.
Furthermore, as the ice removal device is located
only on the side of the drum on which ice is formed, the
continual unbalanced force applied to that side of the drum
to fracture the ice from the freezing surface accelerates the
wear on the drum bearings.
A further disadvantage of knoTwn ice making ma¢hines
of the drum type is that their capacity cannot ~e readily
increased. If increaRed capacity i~ desired, it is usually
necessary to install a whole new machine. That is, in
addition to installing an extra refrigerated drum, it is
also necesæary to in~tall another rsfrlgeration unit
inoluding motor, compres~or and conden60r, and a new drive
unit. Any upgrading in capacity will therefore involve
considerable expensQ.
With a view to overcoming the above deficribed
problems and inoreasing the produat-ion oapacity of ioe
making machines, it has been proposed to use refrigerated
discs. U.S. Patent No.-3,863,462 describes a large scale
flake ice producing machine which oomprises one or more
upright refrigerated disas rotatable on a horizontal ~ha~t.
Water or other congealable liquid ~is applied to both
surfaces of the disc and frozen lnto sheets of ice as the
;~ disc rotates. Thereafter, the sheets are removed from the
disc in ice flakes. Each disc is approxima,~ely 1.8m in
diameter and comprises a pair of large round aluminium plates
spaced apart about 20mm and sealed at their periphery to
form an enclo~ed space. Baffles are placed within the
interior of the pace to form rudimentary passage~ through
which a coolant is pumped in order to refrigerate the disc
surfaces.
However, the flake ice producing machine of U.S.
Patent No. 3,863,462 possesses several inherent
disadvantages, including:
~ (a) Due to the large flow passages inside the disc, it
is necessary to use a non-evaporative coolant such
as brine or glycol. That is, a "boiling" or
evaporative refrigerant which cool~ by direct
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expansion is not suitable for use in the disc of
U.S. Patent No. 3,863,462. Brine and glycol have
low cooling capacity and large amounts of such
coolants must be pumped through the disc in order to
achieve the required eooling.
tb) Since a aoolant such a~ brine or glycol must be
used, a separate refrigeration plant is required in
order to chill the brine or glycol.
(e) The discs are diffieult to manufacture accordiny to
the toleranees required. The 1.8m diameter discs
must be cast and machined, and welded at their
periphery, yet the flat outer surfaces of the discs
must not vary from the plane in which they rotate by
more than 1/8 mm.
For the foregoing reasons, the ice making machine of
U.S. Patent No. 3,863,462 is not considsred to be
co~mereially aceeptable.
It i8 an object of the prssent invention to overeome
or ameliorate at least ~ome of the abovede6eribed
disadvantages of the prior art by providing an improved iee
making maehins.
It is another objeet of the present invention to
provide an improved refrigerated diso for use with the iC8
maki~g machine.
SUMMARY OF ~HE INVENTION
. ~ Aeeording to a first aspeet of the pre3ent
invention, thare is provided an ia9 making apparatus
eomprising at least one rotatable refrigerated di~c member;
means for applying liquid to both sides of said dise member
at a first location, whereby at least some of said liquid
ii adheres to both surfaees of said disc member and is frozen as
said dise member rotatesj and means for removing the frozen
liquid ~rom the sides of said disc member at a second
loeation angularly displaced from said first location in the
directio~ of rotation; characterised in that each said disc
member has a plurality of relatively narrow internal channels
for pa~sage of an evaporative coolant therethrough, said
~;channels extending substantially over all of the operative
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portion of the disc member.
Typically, the liquid applied to the disc member is
water which is frozen to form ice. The ice is removed in the
form of flake ice as hereinbefore described.
The water may be applied to the surface of the disc
by rotating the disc through a water trough or the like.
Alternatively, the water may be sprayed onto the disa.
Preferably, the ice removal means comprises a pair
of harvesting blades juxtaposed with, and extending radially
along respective opposite sides of the disc. Each
harve~ting blade does not contact the disc but is spaced
therefrom by a small cleara~ce, typically 0.05 -1.0 mm. ~he
ice is removed without introduced heat.
- As the disc rotates, each point on the operative
surfaces of the disc will undergo the following s~eps in
sequence: (1) water will be applied to the disc surface, (2)
the water will freeze into ice as the disc rotates with time,
(3) the lce will be removed by the ice removal means, and
the above sequence is repaated with each revolution of the
disc in a continuous process.
It will be apparent to those skilled in the art that
ice making apparatus of the present invention has few moving
part~ and i8 relativ~ly economical to manufacture.
Furthermore, the ice making apparatus is able to
utilize direct expansion rafrigeration with a "boiling" or
evaporative refrigsrant thereby enabling higher efficiency
and ~reezing capacity to be achieved. Only one refrigeration
system is required, the disc(s) constituting the evaporator
of the refrigeration system.
According to a second aspect of the invention, there
is provided a refrigerating disc suitable for use in an ice
making machine, said disc having a plurality of relatively
narrow internal channels for passage of an evaporative
coolant therethrough, said channels extending substantially
over all of the operative portion of the disc.
The disc typically is circular in shape and is
adapted for rotation about an axis passing through its
geometric~centre.
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1331287
Preferably, the disc is of sandwich or laminate
construction comprising two halves in which open channels
have been etched or machined in patterns which are mirror
images of each other. When the two halves are sandwiched
together to form the composite disc, opposed open channels
form closed internal channels. The pattern of the ahannels
i8 such that they extend over substantially all of the plane
of the disc and are substantially of equal length so that the
disc is cooled evenly.
In a single disc machine, the refrigerated disc has
I a central aperture having a collar fitted therein. On one
side, the collar receives a hollow shaft delivering the
aompressed refrigerant. The collar has a series of-radial
¦ bores, communiaating at their inner ends with the hollo~
lS shaft. At their outer ends, the radial bores communicate
I with respective i~lets to the channels extending through the
¦ disa, the channel inlets being located o~ the cylindrical
surface of the disc aperture. ~he liquid refrigerant
paQses through the hollow shaft and into the internal
channels of the disc whereat it evaporates to thereby cool
the disc.
~ he channel outlets communicate with another hollow
shaft on the oppo~ite side of the collar via a second set of
radial bores in the collar. The evaporated refrigerant is
extraated through this hollow shaft to the aompressor. The
disc, collar and shafts form a single asssmbly which is
; rotated by a motor u~ing a belt or chain drive to a pulley or
sprocket on one of the ~hafts.
However, the disc can be rotated in any other
suitable manner. For example, the disc can be provided with
a toothed perimeter so that the disc can be driven by a cog-
wheel gear, either directly or chain-driven.
In a multiple aiSc machine, a number of discs are
mounted on a common shaft and refrigerant is fed to the
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35~ channels in each disc via a distributer and pipe lead system.
The discs are fed in parallel, and the lengths of the pipe
leads are made substantially equal to ensure equal pressure
drop in the refrigerant feed to the discs. ~he evaporated
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~33~287
refrigerant can be extracted via the common hollow shaft.
Preferred embodiments of the invention will now be
described by way of axample with reference to the
accompanying drawings.
5BRIEF DESCRIPTION OF THE DR~WINGS
Fig. 1 is a side elevational view of the ice making
apparatus of one embodiment of the invention;
Fig. 2 is a sectional elevational view along A-A of
Fig. 1;
10Fig. 3 is a sectional side elevational vi~e,w of the
disc mounting arrangement of Fig. 1;
Fig. 4 is a sec~ional vi~w of a quadrant of the di~c
of the ice making apparatus of Fig. 1;
Fig. 5 is a s~ctional view of part of the disc of'
Fig. 4;
Fig. 6 is a sectional view of part of one half diso
of Fig. 4;
Fig. 7 is a sectional elevational view along B-B of
Fig. 3;
20Fig. 8 is a sectional slevational view along C-C of
Fig. 3;
Fig. 9 is an elevational view of the ice removal
means of Fig. 2;
Fig. 10 is an end elevational view of the ice
removal means of Fig. 9;
Fig. 11 is a plan view of the ice removal means of
Fig. 9;
Fig. 12 is a perspective Vi8W of a multiple disc ice
making apparatus according to another embodiment;
3Q Fig. 13 i8 a sectional view of the multipl8 di,sc
machine of Fig. 12;
Fig. 14 is a plan view of the ice removal means of
Fig. 12;
Fig. lS i6 a side view of the ice removal means of
Fig. 14;
Fig. 16 is a sectional view of the shaft of Fig. 12;
and
Fig. 17 is a sectional view of the disc mounting on
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7 1331~87
the shaft of Fig. 16.
DESCRIPTION OF PREFERRED EMBODIMENT
AS shown in the Figs. 1 and 2, the ice making
machine 10 of a first embodiment of the invention oomprises a
frame 12 on which are mounted a water reservoir 11 and a pump
13. Water rom the reservoir 11 is pumped by pump 13 through
upwardly extending pipe 14 to a pair of water sprays 15
loaated abovs and on respective sides of a rotating
refxigerated disc 20. The water sprays are orie~ted to
direct water o~to both surfaces of the disc to thereby leave
a fllm of water adhering to both disc surfaces. The disc 20
¦ rota~ec in the direction indicated by the arrow in Fig. 1 and
is driven by motor 16 via a belt or chain 17 and pulley 18.
However, the disc 20 may be rotated by any other sui~able
means. For example, the disc 20 may be pxovided with a
toothed perimeter and driven by a cog-wheel gear either
direct~y or by chain.
The refrigerated disc 20 has a plurality of channel~
the~ein and constitutes the evaporator in a refrigeration
circuit. The mounting of the refrigerated diso 20 is shown
in more detail in Fig. 3. As can ~e sean in that drawing,
the disc 20 has a central circular aperture having a circular
colla~ 22 inserted therein. On one side, the collar 22
receives a hollow æhaft 18 delivering refrigerant while on
it6 other side, the collar 22 receives another hoLlow shaft
21 for removing the evaporated refrigerant. The sha~ts 18,
21, collar 22 and disc 20 are fixed relative to each other
and rotate as a single assembly. To enable rotation, shaft
18 is mounted in bearing 25 while shaft 21 is mounted in
bearing 23. The bearings 23, 25 are located in respective
bearing blocks which preferably are adjustably and removably
mounted within the frame 12 of the ice making machine.
Hollow shafts 18 and 21 communicate respectively with the
condensor and compressor (not ~hown) of a refrigeration
circuit.~ O-ring~ 26, 24 are provided to seal the
connections to the hafts 18~ 21 respectively.
Shaft 21 ha~ attached thereto a pulley, sprocket or
cog 18 which is rotated by motor 16 via belt or chain 17.
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8 1331~87
Rotation of the pulley 18 in turn rotates the
disc/collar/pipe assembly.
The refrigerated disc 20 is shown in more detail in
Figs. 4-6. The disc 20 is of laminated construction and
comprises two discs 20A and 20B sandwiched together. Each
disc 20A, 20B has a pattern of Open channels 30A formed in a
~urface thereof, for example by etching or machining. The
channel patterns are mirror images of each other so that when
the discs 20A and 20B are bonded together, closed channels 30
are formed. The disc is typically 4-10 mm thick, and the
ahannels are typically 3.5 mm wide x 2.5 mm high.
The channel pattern for a quadrant of the disc 20 is
shown in Fig. 4. ~he pattern for the bottom right quadrant
is the inverse to the illustrated pattern for the top right
quadrant, and the patterns for the top and bottom left
quadrants are mirror images of the patter~s for the top and
bottom right quadrants, respsctively. The chan~el pattern is
~o designed that
(a? the ohannels are spread over substantially the whole
operative surface of the disc 50 that all points on
the surface are close to the refrigerant, and
(b) the channals are of substantially equal lsngth 80
that there is uniform pressure drop in the
` rafrigerant in all the channels.
These two features ensure that th~ disc is
refrigerated aR uniformly and evenly as possible. Moreover,
the provision of a pattern of thin channeIfi enables the disc
to be ~refrigerated using an evaporative or "boiling"
refrigerant as opposed to brine. Faster and more efficient
cooling of the disa is therefore obtained.
;i Although the illustrated disc is composed of two
layers, more than two layers can be used to form the
laminated disc if desired.
Each channel 30 has an inlet 31 communicating with
the central aperture in the disc. The outlets of the
channels 30 are also located on the inner cylindrical surface
of the disc, on the opposite side to the inlets.
As shown in Figs.- 3, 7 and 8, the collar 22 has a
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9 ~331~87
plurality of radial bores 27 on one half which communicate at
their inner ends 32 with ths hollow shaft 18 and at their
outer ends with the inlets 31 of the channels 30 in the disc
20. On the opposite half, the collar 22 is provided with a
plurality of radial bores 29 having outer ends communicating
with the outlets 33 of channels 30 and inner ends
communicating with axial bores 28 which, in turn,
communicate with the hollow shaft 21.
Conden~ed liquid refrigerant is fed via shaft 18
through radial bores 27 in the collar 22 and into the
channels 30 in the disc 20 where it evaporates to cool the
disc. The evaporated refrigerant is drawn from the channel
outlet~ 33 through bores 20 and 28 and out through the hollow
shaft 21 to the compressor (not ~how~) in the refrigeration
circuit. In this manner, the disc acts as tha evaporator in
the refri0eration circuit.
As shown in Fig. 2, ice removal maans 40 are mounted
on frame 12 for fracturing the ice formed on the disc from
the refrigerated 6urfaces. After being broken off the disc,
the ice falls down chute 50 to be collscted in ice bin 51.
An embodiment of a harvesting blada assambly ls
~ shown in Figs. 9 - 11. In this embodiment, harvesting blades
i 52 are fixed to the bottom edge of a respective one of a pair
of radial arm members 53 whiah in turn are fixed to ~upport
25 plate 51 which i8 fastened by bolt 59 to cross beam 56 in the
frame 12 of the ice making machine. The inner ends of arms
53 are supported by pendant arm 54 which i8 pivotally
attached to bracket 55 on the machine frame. As this
mounting arrangement is supported by the ~ain frame rathsr
30 than the shafts 18, 21, it eliminates pressure on bearings 23
and 25 and prolongs the life of such bearings.
The harvesting blade assembly shown in Figs. 9 - 11
also comprises a bearlng block 58 hsld between a pair of
brackets 57 to maintain correct relative alignment between
the disc 20 and the working edges of the harvesting blades
52.
The harvesting blade assembly is of simple economic
construction yet is easy to adjust and to ~aintain.
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t3312~7
Moreover, the harvesting blade assembly harvests the ice on
both sides of the disc 20 at the same angular location so
that the forces on the disc are balanced.
Since ice is formed on both sides of the disc 20,
the ice making machine of the present invention can be made
more compact than known drum machines in which ice i6 formed
on only one side of the drum. Moreover, as the freezing
surfaces of the di~c are in close proximity to the
refrigerant, grsater efficiency i8 achievad. The ice making
machine has few moving parts, thereby reguiring less
maintenance than existing machines. In the event that
maintenance i6 required, the disc/shaft/beaxing assembly
shown in Fig. 3 can easily be removed from the bearing mounts
in the machine.
The machine can be started and stopped
intermittently and the speed of the disc can be varied to
produce product~ of different clarity and con~i6tency. A
single 500 mm diameter disc can produce over half a tonns of
ice in a twenty-four hour period.
Another embodiment of the present invention i~
illustrated in Figs. 12 to 17, this embodiment utilising a
~- - plurality of refrigerated di6cs. A~ shown in Figs. 12 and
13, the multi-disc ice making maohine of the invention
comprises a number of refrigerated discs 70 mounted on a
common hollow shaft 71. The shaft 71 is mounted at its ends
on oombined bearing and seal assemblies 65. An inlet port 68
: i8 provided at one end of the hollow shaft 71 for connection
to a source of condensed liquid refrigerant, while the
opposite end of the shaft 71 has an outlet port 67 for a
suction connection for the evaporated refrigsrant. The
discs 70 constitute the evaporator of a refrigeration circuit
in a similar manner to the embodiment of Figs. 1 to 11.
The discs 70 are mounted in a water tank 69, which
typ~cally is made of stainless steel or glass reinforced
plastic. The tank 69 is mounted on a base 61, which is
suitably madP of cast aluminium alioy. Spaced pairs of
flanges 72 are formed on the tank 69, each disc 70 passing
between a respective pair of flanges 72. Scraper blades 75
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are provided at the top of respective flanges 72 for
fracturing the ice sheet formed on the discs 70 as the discs
rotate past the blades.
~he discs 70 and shaft 71 are rotated by a pulley or
sprocket 64 coaxially mounted on the shaft 71 and driven, by
chain or belt, by a drive motor 63 via a reduction gear box
62. However, it will be apparent to those ~killed in ~he art
that other means of rotating the discs 70 may be provided.
For example, the pulley or sprocket 64, or one or more of the
disc~ 70, may be provided with a toothed circumference and
driven directly by a oog-wheel gear.
The tank 69 is fil}ed with water to the level 80 as
indicated in Fig. 13. ~s the disc 70 moves through the water
in tank 69, a film o~ water will adhere to both surfaces of
the disc due to surface ten6ion. As the refrigerated disc 70
rotates in the clockwise direction as shown, the water
adhering to the refrigerated surfaces of ths disc will freeze
to form a thin sheet of ice which is subsequently fractured
from the disc surface by scraper blades 75 positioned as
shown. Any water not adhering to the surface of the disc 70
or not being frozen will fiimply trickle back into the tank
69. Accordingly, there is little wastage of the liguid to be
frozen.
Ice production can be increased by reducing the
temperature of water in tank 69 to close to freezing point,
increasing the speed of rotation of disc 70 and increasing
the ilow of refrigerant through the disc 70.
The des`ign and construction of each refrigerated
disc i8 substantially as hereinbsfore described with
reference to Figs. 4-6.
An exemplary ~orm of the scraper blade is
illustrated in Fig6. 14 and 15. Each scraper blade 75 is
removably mounted on top of its respective flange 72 by
sultable fasteners through holes 77. Each scraper blade 75
comprises a ~eries o~ teeth 76 for fracturing the sheet ice
- from the refrigerated surfaces of the discs 70. The scraper
blades are hardened and tempered to resist wear. The only
substantial wear in the machine is the abrasion of the ice
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against the scraper blades, and the scraper blades 75 can
easily be removed for replacement and/or re~harpening.
The feeding of refrigerant to the discs 70 is
illustrated in Figs. 16 and 17. A four-way liquid
refrigerant distributor is provided at the inlet port 68 of
the hollow shaft 71. The four-way distributor comprise~ four
copper distributor tubes 81-84 which communicate with the
channelz in re~pective disc~ 70. The lengths of the
distributor tubes 81-84 from ~he inlet port 68 to thei~
respective discs 70 are made equal in order to obtain equal
pressure drop in the refrigerant feed to each disc.
The delivery end of each distributor tube 81-84 is
raoeived in a radial bore in a respective collared portion of
the hollow shaft 71 on which an associated diia 70 is
mounted. Each disc 70 is mounted to a collared portion by
~ean~ of a clamping ring-nut 78. ~n internal elliptloal bore
formed i~ the centre of each clamping ring-nut 78 to
provide an inlet ohamber 73 between the delivery end o~ the
respeetive delivery tube 81-84 and the cha~neils i~ the
associated disk. Refrigerant delivered through tubes 81-84
fills the receptiv6 chamber6 73 which communicate with the
channel openings 31 of each respective disc 70. Re~rigerant
flows through the channels 30 of each respective disc whereat
it i6 evaporated to cool the di6cs. The evaporated
refrigerant is extraeted via the channel outlets which
aommunicate with a suction chamber 74 formed between the
shafts 71 and the disc 70 by the elliptical aperture in the
elamping ring-nut 78. The suction cha~ber 74, in turn,
communicates with the interior of the hollow shaft 71 via
slots 79 cut into the shaft 71. The refrigerant is extracted
from the interior 80 of the hollow shaft 71 via the outlet
port 67 for delivery to the compressor of the refrigeration
circuit.
The foregoing descr$bes only some embodiments of the
pre ent invention and modifications which are obvious to
those skilled in the art may be made thereto without
departing from the scope of the invention. For example,
although a circular disc i6 preferred, the ice making
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13 1331287
machine may use a disc of other shape such as hexagonal or
octagonal. ~he construction of the disc can be varied to
include more than two layers bonded or brazed together, or
alternatively, the disc can be manufactured by sandwiching a
pipe coil between two flat metal discs.
In an alternative embodiment of the invention (not
illustrated), the disc is held stationary and the ice removed
by a rotating blade. The blade can be ~itted with wa~er
application means on its trailing side so that as the lsading
edge removes the ice from the disc, the trailing edge leaves
a layer of water which freezes by the time that the leading
edge completes a full revolution. ~he water application
means can take the form o~ a series of water jets or sprays.
While the ice making machines have been described
with particular reference to flake ice manufacture, the
invention i8 not limited thereto. For example, the ice
making machine~ of the pre3ent invention may also be use~ to
manufacture a ~lush ice product ~rom ~ruit juice or cordial.
On a larger scale, the machines could al80 be u~ed to make
imitation snow.
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