WO2014081990A1

WO2014081990A1 - Ice maker with slush-avoiding sump

Info

Publication number: WO2014081990A1
Application number: PCT/US2013/071358
Authority: WO
Inventors: Steven Trulaske; John Broadbent
Original assignee: True Manufacturing Co., Inc.
Priority date: 2012-11-21
Filing date: 2013-11-21
Publication date: 2014-05-30

Abstract

An ice maker includes an evaporator with ice-forming molds on a surface thereof. Water is streamed over the evaporator and into a sump located below the evaporator and catches water that falls. There is further a pump having a water inlet for pumping water from the sump to the distributor conduit. The sump defines a first area and a second area divided by a barrier. The barrier separates water falling from the evaporator into the first area of the sump from water that has not as recently fallen from the evaporator and is located in the second area of the sump. The water inlet of the pump is positioned to be capable of drawing water located in the second area of the sump in the event that the water in the first area of the sump begins to turn to slush.

Description

ICE MAKER WITH SLUSH-AVOIDING SUMP

The present invention claims priority to U.S. Provisional Patent Application No. 61/729,187, filed November 21, 2012.

FIELD OF THE INVENTION

This invention relates to ice makers generally and in particular to ice maker that comprises a sump that avoids the formation of slush within the sump.

BACKGROUND OF THE INVENTION

Ice cube makers employing gridded freeze plates forming lattice-type cube molds and having gravity water flow and ice harvest are well known and in extensive use. Such machines have received wide acceptance and are particularly desirable for commercial installations such as restaurants, bars, motels and various beverage retailers having a high and continuous demand for fresh ice.

In these ice makers, water is introduced at the top of a freezing grid which directs the water in a tortuous path toward a sump. The frozen product collects on the freezing grid and is sensed by suitable means to defrost the grid whereupon the frozen product is discharged therefrom into a bin. Control means associated with the bin are provided to control the operation of the device to insure a constant supply of frozen product. A refrigeration system incorporating a compressor, condenser, evaporator and expansion valve is common. The evaporator tubing is in direction physical connection with the freeze plate in order to freeze the ice.

The water is recirculated across the freeze plate until it freezes, but commonly water falls from the freeze plate back to the sump over and over until the charge of water cools and begins to reach the freezing point. Water in the sump can actually fall below the freezing point of the water before ice begins forming on the freeze plate.

As a result, it is not uncommon for the water in the sump to begin to freeze or "slush up" on occasion. A "slush-up" situation happens when the water that is being recirculated over the freeze plate sub-cools below 32°F and then suddenly begins to freeze. A single ice crystal in the sub-cooled water will very quickly propagate through all the water, turning all the subcooled water to slush. When this happens, water cannot be pumped from the sump across the freeze plate. The water in the ice machine will thus stop flowing. The water in the sump will then no longer be cooled by passing across the freeze plates and will begin to warm. As the water warms, the slush thaws back to liquid water.

As a result of the "slush-up" situation, the ice machine will stop refrigerating the water and making ice for a few minutes. This "slush up" situation represents inefficiency in the ice making cycle in that for a period of time water is not cooled and time for making ice is wasted until the sump water is warmed past the melting point. In the past, to solve this problem some ice machines have turned off the water pump for a short time during each ice production cycle to allow the evaporator to get much colder such that the water will freeze on the freeze plate more quickly and the water will not subcool. This is not the most efficient way to make ice, though the "slush up" problem is prevented.

There is need in the art to prevent a "slush up" situation in the sump of an ice maker without turning off the water pump thus avoiding the resulting delay in the ice making process. SUMMARY OF THE INVENTION

The present invention provides an ice maker comprising a cabinet having an ice storage bin and an ice making portion. The ice making portion comprises a refrigeration compressor, a condenser and an evaporator assembled in a closed refrigeration circuit. The evaporator has ice-forming molds on a surface thereof. A water supply system has a distributor conduit located above the evaporator for supplying water to the ice-forming molds of the evaporator by means of gravity. A sump is located below the evaporator and for catching water that falls from the ice-forming molds of the evaporator. There is further a pump having a water inlet for pumping water from the sump to the distributor conduit. The sump comprises a first area and a second area divided by a barrier. The barrier separates water falling from the evaporator into the first area of the sump from water that has not as recently fallen from the evaporator and is located in the second area of the sump. The water inlet of the pump is positioned to be capable of drawing water located in the second area of the sump in the event that the water in the first area of the sump begins to turn to slush.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is perspective view of an ice maker according to an embodiment of the present invention;

FIG. 2 is diagrammatic view of the refrigeration system according to an embodiment of the present invention;

Fig. 3 is an ice mold and sump according to an embodiment of the present invention;

Fig. 4 is a perspective view of a sump according to an embodiment of the present invention; and

Fig. 5 is a top view of a sump according to an embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiment illustrated.

Referring to FIG. 1 of the drawings, a commercial type ice making machine 10 of the present invention is housed in cabinet 12 having a lower housing or cabinet section 14 that includes a front ice receiving and storing compartment 16 accessible through door 17 and an upper refrigeration compartment 20 housing the compressor-condenser units of a closed refrigeration circuit 19 (Fig. 2). The upper section 20 of ice making machine 10 includes an evaporator unit attached to an ice making grid 21 in an ice freezing compartment 22, which is located above a lower water pump compartment or sump 24. The various compartments of the ice maker cabinet 12 are closed by suitable fixed and removable panels to provide temperature integrity and compartmental access, as will be understood by those in the art.

Referring now to FIG. 2, the closed refrigeration system 19 housed in compartment 20 includes a refrigeration compressor 28 and an air cooled condenser 30, the high pressure discharge side of the compressor being connected by discharge line 29 to the condenser 30. Saturated liquid refrigerant flows from the condenser 30 through liquid line 31 having a filter/drier unit 32 therein, and is connected to a typical thermostatic expansion valve 33 which meters refrigerant into the inlet side of the evaporator unit 21 in the freeze compartment 22. The outlet of the evaporator is connected by suction line 34 to the suction side of the compressor 28. The normal refrigeration cycle is typical— the compressor 28 supplies high pressure hot refrigerant gas to the condenser 30, where it is cooled to its saturation temperature and liquified refrigerant flows to the evaporator 21 through expansion valve 33. The expanding vaporization of liquid refrigerant in the evaporator removes heat from the water on the evaporator face plate thereby forming the ice cubes in the lattice molds thereon, and the gaseous refrigerant is returned to the compressor suction side to complete the refrigeration and freeze cycle.

The system 19 also includes a hot gas by-pass line 35 connected between the discharge line 29 and the evaporator inlet side downstream of expansion valve 33, and being controlled by solenoid valve 36 to initiate an ice harvest cycle.

FIG. 3 illustrates the water supply system of the ice maker of the invention. In FIG. 3, the evaporator is shown as having ice forming molds 44 on one side thereof with the other side being mounted to the back wall of the water system compartment. Centered above the evaporator unit 21 is a distributor tube 40 which supplies water to the molds 44 by flowing water across the top plate 42 and into the molds 44 for gravitational feeding. Transit water which is not frozen or otherwise adheres to the mold 44 is collected in a sump 46 which feeds water to water pump 50. Water supplied from the sump 46 to the water pump 50 is pumped through feed line 52 to the distributor manifold or tube 40.

Referring to Figs 4 and 5, the sump 46 is shown and described. The sump

46 comprises a first area 54 and a second area 56 separated by a barrier 58. The barrier 58 separates the first area 54 where water is falling from the mold 44 into the sump 46 from the second area 56 which is generally separated from the potentially sub-cooled water falling from the mold 44. The water pump 50 is located in the area 60 of the sump and is located such that it primarily draws water from the first area 54 containing water from the mold 44. This water tends to be colder than water from the second area 56 which is not primarily being pumped and circulated over the mold 44. Because the water that is being actively re- circulated (from area 54) gets slightly colder than the water is not being actively re-circulated (from area 56), the re-circulated water will slush whereas the non- recirculated water will not. The barrier 58 prevents the water in area 56 from mixing with the water in area 54. This prevents the water in area 56 from subcooling or turning into slush. If and when the re-circulated water in the first area 54 turns to slush, the barrier 58 allows the water pump 50 to draw water from the second area 56. Thus the pump 50 can draw warmer liquid water instead of attempting to draw slush. Because of this, the water pump 50 does not clog, and water can continue to flow and make ice. The slush that forms in the recirculation area (first area 54) will warm to the temperature of the cabinet 22, melt and dissipate in a few minutes. Thus the no-slush sump allows the slush to dissipate without clogging the pump and stopping the ice making process.

The above example shows that the invention, as will be defined by the claims, has far ranging application and should not be limited merely to the embodiment shown and described in detail. Instead the invention should be limited only to the explicit words of the claims, and the claims should not be arbitrarily limited to embodiment shown in the specification. The scope of protection is only limited by the scope of the accompanying claims, and the Examiner should examine the application only on that basis.

Claims

We claim:

1. An ice maker comprising:

a cabinet having an ice storage bin and an ice making portion comprising a refrigeration compressor, a condenser and an evaporator assembled in a closed refrigeration circuit, the evaporator comprising ice-forming molds on a surface thereof;

a water supply system comprising a distributor conduit located above the evaporator for supplying water to the ice-forming molds by means of gravity, a sump located below the evaporator and for catching water which falls from the ice-forming molds of the evaporator, and a pump having a water inlet and for pumping water from the sump to the distributor conduit;

the sump comprises a first area and a second area divided by a barrier that separates water falling from the evaporator into the first area of the sump from water that has not as recently fallen from the evaporator and is located in the second area of the sump; and

the water inlet of the pump being positioned to be capable of drawing water located in the second area of the sump in the event that water in the first area of the sump begins to turn to slush.

2. The ice maker of claim 1 wherein the first area is smaller than the second area.

3. The ice maker of claim 2 wherein the first area is less than half the size of the second area.

4. The ice maker of claim 3 wherein the first area is less than 25% of the size of the second area.