SANITARY EVAPORATOR ASSEMBLY

Abstract

An ice maker evaporator assembly having an evaporator pan with a back wall and left, right, top and bottom sidewalls extending from the back wall, and a freeze plate located within the evaporator pan. Refrigerant tubing is thermally coupled to the back wall of the evaporator pan opposite the left, right, top and bottom sidewalls. A first layer of insulation is formed on the refrigerant tubing. An evaporator housing having a housing back wall and housing left, right, top and bottom sidewalls extending from the housing back wall is attached to the evaporator pan and covers refrigerant tubing. A second layer of insulation is formed on top of the first layer of insulation.

Claims

1-20. (canceled)

21. An ice maker comprising: a freeze plate having a front side and back side, the freeze plate configured to receive water at the front side and to form the water received at the front side into a plurality of pieces of ice; refrigerant tubing thermally coupled to the back side of the freeze plate opposite the front side; and an evaporator housing attached to the freeze plate and defining an enclosed cavity behind the back side of the freeze plate, the evaporator housing containing the refrigerant tubing inside the enclosed cavity; wherein the enclosed cavity is sealed water tight.

22. The ice maker as set forth in claim 21, wherein the freeze plate comprises an evaporator pan and vertical and horizontal strips arranged in the evaporator pan to define a lattice of ice cube molds.

23. The ice maker as set forth in claim 21, wherein the freeze plate has a perimeter wall and wherein the evaporator housing has a perimeter wall sealingly engaged with the perimeter wall of the freeze plate.

24. The ice maker as set forth in claim 23, wherein the ice maker comprises a gasket compressed between the perimeter wall of the freeze plate and the perimeter wall of the evaporator housing.

25. The ice maker as set forth in claim 23, wherein the evaporator housing further comprises a back wall sealingly engaged with the perimeter wall of the evaporator housing.

26. The ice maker as set forth in claim 25, further comprising a weld joint sealing the back wall to the perimeter wall of the evaporator housing.

27. The ice maker as set forth in claim 26, wherein the perimeter wall comprises a groove and the back wall comprises an edge seated in the groove, the weld joint being formed along the groove.

28. The ice maker as set forth in claim 27, wherein the edge is a raised edge.

29. The ice maker as set forth in claim 26, wherein the weld joint is formed by an ultrasonic welding process.

30. The ice maker as set forth in claim 29, wherein the perimeter wall and the back wall of the evaporator housing are formed from plastic material.

31. The ice maker as set forth in claim 28, wherein the back wall has a perimeter edge margin and wherein the raised edge extends 360 about the perimeter edge margin of the back wall.

32. The ice maker as set forth in claim 25, wherein the perimeter wall of the evaporator housing is formed from individual housing left, right, top and bottom sidewall pieces joined together.

33. The ice maker as set forth in claim 32, wherein the individual housing left, right, top and bottom sidewall pieces comprise gasket material for sealing the evaporator housing water tight.

34. The ice maker as set forth in claim 23, wherein the perimeter wall of the freeze plate comprises studs and wherein the perimeter wall of the evaporator housing is secured to the freeze plate by the studs.

35. The ice maker as set forth in claim 21, further comprising a layer of insulation formed on the refrigerant tubing and the back side of the freeze plate.

36. The ice maker as set forth in claim 35, wherein the layer of insulation comprises an integral layer of cured-in-place insulation that conforms to refrigerant tubing and the back wall of the evaporator pan and is impervious to water such that the layer of insulation has no joints through which water can leak onto the back side of the freeze plate.

37. The ice maker as set forth in claim 36, wherein there is a cavity between the layer of insulation and the evaporator housing.

38. The ice maker as set forth in claim 37, wherein the cavity is filled with another type of insulation.

39. A method of making the ice maker of claim 1, the method comprising: sealingly attaching a perimeter wall of the evaporator housing to the freeze plate; and sealingly attaching a back wall of the evaporator housing to the perimeter wall.

40. The method of claim 39, wherein said sealingly attaching the back wall comprises ultrasonically welding the back wall to the perimeter wall to form a weld joint that seals an entire interface between the perimeter wall and the back wall water-tight.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0010] These and other features, aspects and advantages of the invention will become more fully apparent from the following detailed description, appended claims, and accompanying drawings, wherein the drawings illustrate features in accordance with exemplary embodiments of the invention, and wherein:

[0011] FIG. 1 is a right perspective view of an evaporator assembly according to one embodiment of the invention;

[0012] FIG. 2 is an exploded right perspective view of an evaporator assembly according to one embodiment of the invention;

[0013] FIG. 3 is a front view of an evaporator pan according to one embodiment of the invention;

[0014] FIG. 4 is a back view of an evaporator according to one embodiment of the invention;

[0015] FIG. 5 is a right view of an evaporator according to one embodiment of the invention;

[0016] FIG. 6 is a rear view of an evaporator housing according to one embodiment of the invention;

[0017] FIG. 7 illustrates a refrigerant tubing covered by a first pourable insulation in accordance with one embodiment of the invention;

[0018] FIG. 8 is a rear perspective view of an evaporator assembly according to an embodiment of the invention;

[0019] FIG. 9 is a perspective view of a back wall of an evaporator housing according to an embodiment of the invention;

[0020] FIG. 10 is an exploded perspective view of a back wall of an evaporator housing according to an embodiment of the invention;

[0021] FIG. 11 is an exploded perspective view of an evaporator housing according to an embodiment of the invention;

[0022] FIG. 12 is an exploded perspective view of portions of an evaporator housing according to an embodiment of the invention; and

[0023] FIG. 13 is a perspective view of the back side of the evaporator housing according to an embodiment of the invention.

[0024] Like reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0025] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of including, comprising, or having and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. All numbers expressing measurements and so forth used in the specification and claims are to be understood as being modified in all instances by the term about. It should also be noted that any references herein to front and back, right and left, top and bottom and upper and lower are intended for convenience of description, not to limit an invention disclosed herein or its components to any one positional or spatial orientation.

[0026] As described herein, embodiments of the invention are directed to an evaporator assembly wherein the back side of the evaporator is covered, insulated, exempt from NSF regulations, and protected from heat loss and the damaging effect of the water and corrosion. Because the back side of the evaporator is covered, it does not need to be plated (with electroless nickel, for example), saving considerable cost and it cannot contaminate the ice making water.

[0027] With reference to FIGS. 1-6, an embodiment of evaporator assembly 100 is described. Evaporator assembly 100 includes evaporator 110 and an evaporator housing formed by housing top 140, bottom 150, sides 160 and 170, and back 180. Preferably, the top 140, bottom 150, sides 160 and 170, and back 180 of the evaporator housing are plastic. The top 140, bottom 150, sides 160 and 170, and back 180 of the evaporator housing may have features allowing them to be assembled together in a variety of ways, including snap-fit features, bolts and nuts, etc. The inner surfaces of the top 140, bottom 150, sides 160 and 170 may include a gasket material to aid in sealing the evaporator housing water tight. Evaporator 110 includes an evaporator pan 120 having a back wall 300 and a left sidewall 310, a right sidewall 320, a top sidewall 330, and a bottom sidewall 340 extending from back wall 300 toward the front side of evaporator 110. Left, right, and top sidewalls 310, 330, 320, are substantially perpendicular to back wall 300 while bottom sidewall 340 preferably angles slightly downward. The evaporator pan 120 includes a series of studs 130 that may be used to mount evaporator assembly 100 to an internal structure of the ice maker (not shown). The evaporator housing may have corresponding mating openings 190, through which the studs 130 may pass.

[0028] A population of vertical and horizontal strips 240, 250 are secured in evaporator pan 120 to form a lattice of ice cube molds. Evaporator pan 120 with vertical and horizontal strips 240, 250 may also be called a freeze plate. Attached to the back side of back wall 300 of evaporator pan 120 is a serpentine tube 200 through which cold refrigerant flows to lower the temperature of evaporator 110 so that ice can be formed therein. Serpentine tube 200 includes inlet tube 220 and outlet tube 210 which extend through evaporator assembly 100, as described more fully elsewhere herein. Locating the inlet tube 220 at the bottom of the evaporator assembly 100 assists in ensuring an even distribution of temperature across the evaporator. The serpentine tube 200 may be attached to the back side of back wall 300 of the evaporator pan 120 in a number of conventional ways, including using a soldering or brazing process.

[0029] The components of evaporator 110 are preferably formed of copper. To satisfy the water contact cleanliness requirements of NSF for commercial ice machines, all areas of evaporator 110 that are considered to be in the food zone of the ice maker cannot be bare copper and thus must be plated. Any portion of evaporator 110 that could potentially drip water into the food zone is considered to be inside the food zone and must comply with this requirement. Because of this requirement, typical ice machine evaporators must be completely plated such that no un-plated, bare copper surfaces are exposed. Typical evaporators are exposed on all sides, thus the entire surface of typical evaporators-front and back-must be plated. This plating, typically a thin layer of electroless nickel (EN), is quite expensive, costing roughly as much as the rest of the evaporator. As described more fully elsewhere herein, because the back side of evaporator 110 is covered by evaporator housing, the back side of evaporator 110 does not need to be plated. Thus only the front side of back wall 300, sidewalls 310, 320, 330, and 340 of evaporator pan 120 are plated. The back side of back wall 300 and serpentine tubing 200 are not required to be plated.

[0030] Referring now to FIG. 6, two passageways 610, 620 extend through back wall 180 of evaporator housing. Passageways 610, 620 permit inlet and outlet tubes 220, 210, respectively, of serpentine tube 200 to pass through back wall 300 of the evaporator housing such that serpentine tube 200 can be coupled with the remaining components of the refrigeration system of an ice maker (not shown). Passageways 610, 620 are preferably circular in shape; however, passageways may be rectangular, square, ovular, etc. without departing from the scope of the invention. Rubber grommets (not shown) may be inserted into passageways 610, 620 to seal any gap between passageways 610, 620 and inlet and outlet tubes 220, 210, respectively, of serpentine tube 200. In certain embodiments, a caulk or sealant may be used in addition to or in place of grommets to seal any gap between passageways 610, 620 and inlet and outlet tubes 220, 210.

[0031] A third passageway 630 may be provided in the back wall 180 in order to inject insulating material into the interior of the evaporator housing assembly 100 as described below.

[0032] As illustrated in FIG. 7, the evaporator assembly 100 further includes an insulating material 710 layered over at least a majority of the length of the serpentine tube 200. The insulating material 710 minimizes the amount of heat dissipated by the serpentine tube 200 and provides a water-tight seal. Preferably, the insulating material 710 is a heavy-bodied, water-based, vinyl acrylic, general-purpose mastic that is typically used in both interior and exterior insulation systems. Examples of insulating material 710 include two-part silicone materials such as QSil 550 from Quantum Silicones LLC of Richmond, VA.

[0033] Preferably, the insulating material 710 is applied in liquid form onto the serpentine tubing 200 to a thickness of approximately about 5 mm to about 12 mm. The insulating material 710 then cures, forming an integral layer of insulation that is impervious to water. In addition, the integral layer of insulation has no joints through which water can leak, will not rust, and adds rigidity and strength. As the insulating material 710 is poured in a liquid form, it cures into a mold that matches the geometry of the serpentine tubing 340 and can fill in all gaps within the back side of the evaporator pan.

[0034] After attaching the serpentine tube 200 to the evaporator pan 120, and adding the insulating material 710 surrounding the serpentine tube 200, the evaporator assembly 100 may be assembled. Thus the five components of the evaporator housing, namely housing top 140, bottom 150, sides 160 and 170, and back 180 may be assembled together surrounding the evaporator pan 110 in order to form the complete assembly 100. Forming the assembly results in a cavity formed between the back side of evaporator 110 (holding the serpentine tube 200) and the front side of back wall 180 of evaporator housing, and further enclosed by the housing top 140, bottom 150 and sides 160 and 170.

[0035] As illustrated in FIGS. 8-13, in certain embodiments, the back 180 may include one or more raised edges 182, 184, 186, and 188. As shown in FIGS. 9 and 10, the raised edges 182, 184, 186, and 188 preferably surround the perimeter of the back 180. The raised edges 182, 184, 186, and 188 extend outwardly away from the inner surface of the back 180 (i.e., the surface facing the serpentine tube 200). As shown in FIGS. 11 and 12, the raised edges 182, 184, 186, and 188 initially rest within grooves 172, 174, 176, and 178 formed in the top 140, bottom 150, and sides 160 and 170.

[0036] The back 180 may then be ultrasonically welded to the top 140, bottom 150, and sides 160 and 170 in order to seal the entire assembly together as shown in FIG. 13. The raised edges 182, 184, 186, and 188, which may be a raised triangular bead of material molded onto the surface of the back 180, concentrate the ultrasonic energy to rapidly initiate the softening and melting of the surface of the back 180 and grooves 172, 174, 176, and 178 as is known to those skilled in the art of ultrasonic welding. During welding, the raised edges 182, 184, 186, and 188 melt flat to seal the back 180 into the grooves 172, 174, 176, and 178.

[0037] In various embodiments, the cavity may be filled with foam after evaporator assembly 100 is assembled. The foam may be open- or closed-cell foam comprised, for example, of polystyrene or polyurethane, etc. Preferably, the foam is an expanding-type foam that can be sprayed into the cavity through passage 630. The foam preferably conforms to the back side of evaporator 110 so that it covers all or substantially all of the back side of evaporator pan 120 and the insulated serpentine tube 200 and fills all or substantially all of cavity. The foam may be sprayed into cavity after evaporator 110 and evaporator housing are assembled together. Another acceptable form is a two-part liquid form sold under the brand name Ecomate, in which the two parts mix and cure in place. After cavity is filled with sufficient amount of foam, a plug (not shown) may be inserted into or over the passageway 630 and may be held and sealed in place by the foam inside cavity. Additionally or alternatively, the plug may be held in by any type of sealant and/or adhesive, including, but not limited to, silicone caulk.

[0038] Filling the cavity provides insulation to the back side of evaporator 110 thus reducing or eliminating extraneous heat transfer on the back side of evaporator 110 which is common with typical evaporators as described more fully elsewhere herein. Consequently, filing the cavity with foam reduces or eliminates the possibility for condensation or frost to form on the back side of evaporator 110, reduces or eliminates the possibility of the back side of evaporator 110 corroding, and increases the efficiency of both forming and harvesting ice cubes from evaporator pan 120 because extraneous heat on the back side of evaporator 110 is essentially eliminated. Furthermore, the foam within the cavity is completely protected from any moisture condensing on the serpentine tubing 200 by the insulating material 710. As an alternative to filling the cavity with foam, the insulating material 710 may be applied to a thicker layer. Alternatively, one may use a single layer of standard blown foam in place of the insulating material 710, particularly if a closed cell blown foam (about 99.5% closed) becomes commercially available.

[0039] The increase in insulation effectively allows one to reduce the size of the evaporator 110, thus minimizing the size of the required compressor and condenser for the identical ice making capacity. In tests of the embodiment described here, an icemaker can achieve slightly larger amounts of produced ice using significantly less energy.

[0040] Thus, there has been shown and described a novel evaporator assembly for an ice maker, particularly useful with batch-type ice makers. It will be apparent, however, to those familiar in the art, that many changes, variations, modifications, and other uses and applications for the subject devices and methods are possible. All such changes, variations, modifications, and other uses and applications that do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.