U.S. patent application number 10/085280 was filed with the patent office on 2003-08-28 for auger-type ice making apparatus with improved evaporator.
Invention is credited to Brunner, Roger Patrick.
Application Number | 20030159459 10/085280 |
Document ID | / |
Family ID | 27753593 |
Filed Date | 2003-08-28 |
United States Patent
Application |
20030159459 |
Kind Code |
A1 |
Brunner, Roger Patrick |
August 28, 2003 |
Auger-type ice making apparatus with improved evaporator
Abstract
An improved evaporator is provided for an ice making apparatus
of the auger-type. The evaporator employs an evaporator body having
spiral grooves cut or milled into its outer cylindrical surface and
a cylindrical jacket disposed over the spiral groove formed on the
outer cylindrical surface of the evaporator body, with the jacket
being in interference-fit engagement against the groove of the
evaporator body. The interference fit is formed by thermal
expansion of the jacket prior to it being telescopically slid over
the body, followed by a cooling-down of the jacket, by which it
shrinks or compresses radially inwardly, to tightly seal against
the outer periphery of the grooves, creating a sealed path for
refrigerant flow, from inlet to outlet of the evaporator.
Inventors: |
Brunner, Roger Patrick;
(Wind Gap, PA) |
Correspondence
Address: |
PAUL AND PAUL
2900 TWO THOUSAND MARKET STREET
PHILADELPHIA
PA
19103
US
|
Family ID: |
27753593 |
Appl. No.: |
10/085280 |
Filed: |
February 28, 2002 |
Current U.S.
Class: |
62/354 |
Current CPC
Class: |
F25B 39/02 20130101;
F25C 1/147 20130101 |
Class at
Publication: |
62/354 |
International
Class: |
F25C 001/14 |
Claims
What is claimed is:
1. An ice making apparatus comprising: (a) a generally cylindrical
and hollow freezing chamber; (b) a compacting head at an end of
said freezing chamber; (c) a rotatable ice auger sized to fit into
said freezing chamber whereby said auger scrapes ice formed on the
walls of said chamber and conveys the ice toward a discharge end of
said auger and said compacting head; (d) an evaporator comprising
an evaporator body and a jacket; (e) the evaporator body having a
continuous generally spiral grove on its outer cylindrical surface,
terminating in a radial outward edge; with the evaporator having a
refrigerant inlet and refrigerant outlet. (f) the evaporator jacket
being telescopically disposed over the spiral groove of the
evaporator body and being in interference fit against the outward
edge of the spiral groove, sealingly engaging the evaporator jacket
against the evaporator body, whereby refrigerant entering into the
groove is sealingly trapped therein between a refrigerant inlet and
a refrigerant outlet.
2. The apparatus of claim 1, wherein the evaporator body includes a
cylindrical groove at a lower end thereof and another cylindrical
groove at an upper end thereof, with the cylindrical groove being
in respective communication with the refrigerant inlet and
refrigerant outlet.
3. The apparatus of claim 1 wherein the jacket is welded to the
evaporator body at both upper and lower ends of the evaporator
body.
4. The apparatus of claim 1, wherein the spiral groove comprises a
helical groove.
5. The apparatus of claim 1, wherein the interference fit is
obtained by a thermally expanded jacket that is subsequently cooled
to effect the interference fit against the outward edge of the
spiral groove.
6. The apparatus of claim 1, wherein the compacting head is annular
and is disposed normal to the axis of the freezing chamber.
7. A method of making an ice making apparatus comprising: (a)
providing a generally cylindrical and hollow freezing chamber; (b)
providing a compacting head at an end of said freezing chamber; (c)
providing a rotatable ice auger sized to fit into said freezing
chamber and disposing the auger in the freezing chamber whereby
said auger scrapes ice formed on the walls of said chamber and
conveys the ice toward a discharge end of said auger and said
compacting head; (d) providing an evaporator comprising an
evaporator body and a jacket; (e) providing on the evaporator body
a continuous generally spiral grove on its outer cylindrical
surface, terminating in a radial outward edge; and providing to the
evaporator with a refrigerant inlet and refrigerant outlet. (f)
telescopically disposing the evaporator jacket over the spiral
groove of the evaporator body to be in interference fit against the
outward edge of the spiral groove and thereby sealingly engaging
the evaporator jacket against the evaporator body, whereby
refrigerant entering into the groove is sealingly trapped therein
between the refrigerant inlet and the refrigerant outlet.
8. The method of claim 7, including providing the evaporator body
with a cylindrical groove at a lower end thereof and another
cylindrical groove at an upper end thereof, so that the cylindrical
groove is in respective communication with the refrigerant inlet
and refrigerant outlet.
9. The method of claim 7, including the step of molding the jacket
is welded to the evaporator body at both upper and lower ends of
the evaporator body.
10. The method of claim 7, wherein the step of providing the spiral
groove comprises forming a helical groove.
11. The method of claim 7, wherein the interference fit is obtained
by thermally expanding the jacket and subsequently cooling the
jacket to effect the interference fit against the outward edge of
the spiral groove.
12. The method of claim 6, wherein the step of providing a
compacting head comprises the step of providing an annular
compacting head, normal to the axis of the freezing chamber.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to auger-type ice making machines
used in a commercial setting, which produce flaked or chipped ice.
Ice is formed by water freezing on the inner wall of a hollow
cylindrical freezing chamber. A rotatable ice auger, sized to
enable the scraping of ice off the inner surface of the freezing
chamber conveys the flaked ice toward an axial end of the freezing
chamber whereby the flaked ice is compressed into a rigid mass of
ice which is subsequently severed into discrete, generally uniform
chunks of ice.
[0002] The present invention is directed toward a new and improved
auger-type ice making machine which has an improved evaporator.
[0003] The present invention is an improvement upon U.S. Pat. No.
5,394,708, the complete disclosure of which is herein incorporated
by reference.
SUMMARY OF THE INVENTION
[0004] This invention relates to an auger-type ice making apparatus
of the type wherein ice is produced on the inner walls of a
cylindrical freezing chamber. A rotatable ice auger scrapes such
walls producing flaked ice.
[0005] In accordance with the present invention, the evaporator of
the auger-type ice making machine comprises a cylinder comprising
an evaporator body of significant wall thickness, which has a
continuous spiral groove cut (preferably milled) on its outer
cylindrical surface. This spiral groove embodies the refrigerant
flow canal. A second cylinder comprises a jacket which is placed
around the evaporator body. The jacket has an interference fit
around the body and can only be slid into place after it is
thermally expanded. Once the jacket has been expanded and slid into
place, it is cooled and, upon being cooled, undergoes a radial
contraction, whereby the inner cylindrical surface of the jacket
seals tightly against the outer diameter of the spiral groove of
the evaporator body, such that refrigerant will flow only along the
spiral groove, confined outwardly of the spiral groove by the inner
cylindrical surface of the jacket. Refrigerant inlet and discharge
ports are provided through the jacket.
[0006] This invention relates generally to an auger-type ice making
apparatus where flaked ice is created on the interior wall of a
cylindrical freezing chamber, scraped of the wall by an ice auger,
and transferred out of the chamber, through a discharge aperture,
to a discharge line.
[0007] It is accordingly a general object of the present invention
to provide a new and improved auger-type ice making apparatus, with
an improved evaporator.
[0008] It is another object of the present invention to provide a
new and improved auger-type ice making apparatus which comprises an
evaporator body having spiral grooves in its outer cylindrical
surface, which grooves, together with the inner cylindrical surface
of a jacket that is first heated or otherwise thermally expanded,
and then allowed to cool, shrinks radially inwardly to form an
interference fit against the continuous spiral groove, such that
refrigerant delivered into and out of the spiral groove is confined
between the evaporator body and the jacket, so as to flow only
along the spiral groove from the inlet thereto, to the outlet
thereof.
[0009] Other objects and advantages of the present invention will
become apparent from the following description taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0010] FIG. 1 is a schematic diagram of an ice making apparatus of
the prior art.
[0011] FIG. 2 is an elevational view, partially broken away and
shown in longitudinal section, of the auger-type ice generating
apparatus embodied on the system shown in FIG. 1.
[0012] FIG. 3 is a perspective view of the evaporator body and
jacket of this invention, shown assembled at the left of FIG. 1,
and shown longitudinally exploded at the right of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] Referring now in detail to the drawings, wherein like
reference numerals indicate like elements throughout the several
views, there is shown in FIGS. 1 and 2 an ice making apparatus in
accordance with one preferred embodiment of the prior art, of which
the present invention is an improvement. The illustrated apparatus
is shown generally as comprising an auger-type ice generating
apparatus 10, with a motor means 26 to drive the ice generating
apparatus 10, an input line for water 18 from a water source 16 to
be frozen, an outlet delivery line 12 for delivery of chunks of ice
to an ice retaining means 14, a refrigeration means comprising a
compressor means 20, a condenser means 22, an expansion valve 27,
and evaporator 24 to supply refrigeration to the ice generating
means 10.
[0014] In operation of the ice maker according to the prior art,
conventional refrigerant under pressure is sent from the compressor
means 20 via line 37 to the condenser means 22. The refrigerant is
thereafter liquefied within the condenser means 22 and then passed
through an expansion valve 27 to the evaporator 24. Evaporator 24,
which completely surrounds the ice making machine 10, boils the
liquid refrigerant under low pressure to extract heat from, and
accordingly cool, the generally cylindrical ice freezing chamber.
Evaporator 24 additionally comprises an evaporator cover 29 which
serves as an insulator and protective cover. Water is supplied to
the cylindrical freezing chamber 30, which houses an ice auger 28,
from a water source 16 through water input line 18. A constant
level of water 25 is maintained in the freezing chamber. Water
freezes on the inner wall 38 of the freezing chamber 30 and is
scraped off by means of the ice auger 28.
[0015] The ice generating apparatus 10 according to the prior art
is shown in greater detail in FIG. 2. The auger 28 is disposed
vertically in the interior of the freezing chamber 30 and is driven
by shaft 44. Actuation of the motor means 26 results in a rotation
of the auger 28 which causes ice to be scraped off the inner wall
38 of the freezing chamber 30 in flaked form. The ice generating
apparatus 10 includes a water inlet 32, formed on its lower end for
receiving water from the inlet line 18, and an ice discharge 34,
formed on the upper end for delivering generated ice to the
delivery line 12. Tubing 36 is also included, wrapped a plurality
of times around the freeing chamber 30 which defines the
aforementioned evaporator 24. Evaporator 24 includes an inlet 33
for receiving the refrigerant from the expansion valve 27, and
refrigerant vapor is passed out through an outlet 35, into outlet
line 54 where, as shown in FIG. 1, it is carried back to the
compressor means 20. The refrigerant extracts heat from the ice
generating apparatus 10 through the walls of freezing chamber 30 as
it is passed through the evaporator 24. This causes some of the
water contained within the freezing chamber 30 to freeze along the
inner wall 38.
[0016] Auger 28 includes at least one coiled band of scrapers 42
extending outward from the auger surface 56, in close proximity to
the inner wall 38 of the freezing chamber 30. A drive shaft 44
connects to the motor means 26 extending axially through the auger
28. Accordingly, as auger 28 is rotated, the scraper 42 shaves the
ice formed on the inside walls 38, carrying it axially upward, in
the form of slush, to be compacted against an annular compacting
head 51.
[0017] As indicated above, the ice discharged through the discharge
34 is sent via line 12 to the retaining means 14.
[0018] The use of a prior art evaporator that includes a wrapping
of copper tubing around a cylindrical body is avoided. In
accordance with the prior art, such a copper tube, when brazed into
a refrigeration circuit, embodies the refrigerant flow canal of the
evaporator. Attachment of the wrapped tube to the cylinder body is
typically accomplished by using a solder to bond them together.
Often the wrapped assembly is dipped into a molten solder tank,
allowing the solder to flow underneath and in between the copper
tubing wrap. Such attachment and subsequent insulation of the
copper tubing wrap is a labor and process intensive endeavor.
Additionally, evaporator performance and reliability depend on
proper execution of the process because proper copper tube
attachment is critical to ensure heat transfer from the water
within the evaporator to the refrigerant in order to freeze the
water, and it is vital that moisture be sealed out of the wrapped
tubing area of the evaporator assembly. If moisture is not sealed
out and ice is formed between the copper tubing wrap and body, the
subsequent expansion and contraction due to freeze/thaw operation
cycles may cause copper wrap separation and/or structural failure
of the body itself. Generally the solder is used not only to bond
the copper tube to the body, but also acts as a moisture seal.
[0019] The problems associated with a wrapped and dipped evaporator
manufacturing process are numerous. For example, the wrapped tube
may tend to distort as it is wrapped around the body, creating
voids and air gaps that can harm performance. Furthermore, the wrap
may tend to "spring" when the assembly is removed from the wrapping
apparatus, so the ends of the copper tube must be attached,
typically via spot welding, to the body, in order to counter such
tendency to "spring". If the wrap is too tight, the solder will not
flow properly. If the wrap is too loose, the heat transfer may not
be appropriate. Furthermore, solder adhesion is problematic,
especially when the body is stainless steel. At a minimum the body
needs to be fluxed in an acid prior to dipping it into a solder, if
not actually pre-tinned prior to wrapping. It has been found that
solder adhesion is critical to evaporator performance.
Additionally, in a wrap assembly, the assembly must be pre-heated
prior to solder dipping, in order to avoid dangerous eruption of
the solder tank which could occur should a cold assembly be
introduced into molten solder. Furthermore, solder must never flow
to the interior of the evaporator body, because of the lead content
of the solder, but sealing of the ends of the evaporator during the
dipping process has been found to problematic. Additionally,
attaching insulation to the exterior of the dipped assembly is
difficult due to the uneven outer surface. Typically, a shell is
placed around the assembly, and a foam-in-place operation is
performed, with the intent of having the insulation flow into the
voids, further sealing the dipped area from moisture.
[0020] Referring now to FIG. 3, it will be seen that the improved
evaporator 125 of the present invention is generally designated in
place of the evaporator 24 of FIGS. 1 and 2, and comprises an
evaporator body 130 and a jacket 131.
[0021] The evaporator body 130 has an inner cylindrical wall 138
and, on its outer cylindrical surface, a spiral groove 140, which
is milled, or otherwise cut into the exterior cylindrical surface
of the evaporator body 130 to define a spiral groove 140 from a
location above the lower end 141 of the body 130, to a location
below the upper end 142 thereof. At opposite ends of the spiral
groove 140 there are circumferential grooves 143, 144.
[0022] A refrigerant inlet port 145 is provided in the cylindrical
jacket 125, fed by the refrigerant delivery line 39 of FIG. 1, with
the refrigerant being carried off via refrigerant discharge port
146, to the refrigerant outlet line 54 of FIG. 1.
[0023] It will be apparent that, except for the evaporator
construction, the ice making apparatus of this invention is in
accordance with the apparatus of FIGS. 1 and 2, with the evaporator
of FIGS. 1 and 2 being replaced by the evaporator construction of
FIG. 3.
[0024] The cylindrical jacket 131 has an interference fit against
the outer peripheral edges 147 of the spiral cut 140, to seal
refrigerant that enters via port 145, to remain within the spiral
groove 140, from its inlet location 145, to its discharge location
146.
[0025] The manner in which the interference fit is achieved is by
heating the jacket 131 prior to sliding it into place over the body
130 of the evaporator 125, whereby the jacket 125 thermally expands
to a greater diameter, or outwardly, in the radial direction. After
the jacket 125 is in place over the body 130, it is cooled and
shrinks or reduces in diameter, or in a radial direction, until the
inner cylindrical surface 148 thereof tightly engages against the
outer peripheral edges 147 of the continuous helical or spiral
groove 140 formed on the outer surface of the body, whereby it
tightly seals thereagainst.
[0026] Thus, refrigerant entering via inlet port 145, into
circumferential groove 143, is caused to pass along the helical
groove until it reaches the upper circumferential groove 144,
whereby it can exit the evaporator via exit port 146, to line 54,
and back to the compressor 20.
[0027] An auger 28 disposed inside the auger body thus, as set
forth in the description above with respect to FIGS. 1 and 2,
scrapes ice from the inner cylindrical wall 138 of the body,
delivering the same upward through the evaporator, to discharge via
ice discharge port 134, to an ice delivery line 12, back to an ice
retaining means 14.
[0028] The jacket 131 is welded to the evaporator body 130 at upper
and lower ends thereof, at locations 150 and 151, as shown in FIG.
3, to ensure proper refrigerant sealing within the groove 140.
[0029] It will be seen that, in accordance with this invention, the
manufacturing process for forming an evaporator is greatly
simplified, in that it is not necessary to use a wrapped tube
construction, and the problems associated with a wrapped tube
construction are thereby avoided. Moreover, the spiral groove that
is formed in accordance with this invention is no longer subjected
to variations that are inherent in a wrapped dipped tube
construction. Additionally, with the present invention moisture can
no longer affect the integrity of the refrigerant path or
evaporator structure. Additionally, in accordance with the present
invention, more simplified forms of insulation can be used, for
example, a simple foam material can be fastened in place to
insulate the evaporator. Additionally, by employing circumferential
grooves at each end of the body, the heat transfer between
thick-walled ends of the evaporator and the spiral groove is
minimized. Furthermore, by locating the refrigerant inlet and
outlet ports 145 and 146 as disclosed herein relative to the spiral
groove 140, refrigerant turbulence can be effected to the highest
degree, with minimal loss due to pressure drop.
[0030] It will be recognized by those skilled in the art that
changes may be made in the above described embodiments of the
invention without departing from the broad inventive concepts
thereof. It is understood, therefore, that this invention is not
limited to the particular embodiments disclosed, but is intended to
cover all modifications which are within the scope and spirit of
the invention as defined by the appended claims.
* * * * *