Abstract:
An ice cube-making machine that is characterized by noiseless operation at the location where ice cubes are dispensed and be lightweight packages for ease of installation. The ice cube-making machine has an evaporator package, a separate compressor package and a separate condenser package. Each of these packages has a weight that can generally by handled by one or two installers for ease of installation. The noisy compressor and condenser packages can be located remotely of the evaporator package. The maximum height distance between the evaporator package and the condenser package is greatly enhanced by the three package system. A pressure regulator operates during a harvest cycle to limit flow of refrigerant leaving the evaporator, thereby increasing pressure and temperature of the refrigerant in the evaporator and assisting in defrost thereof.

Description:
This Application is a division of, and claims priority in, U.S. patent application Ser. No. 09/952,143, filed Sep. 14, 2001, now U.S. Pat. No. 6,637,227, which the benefit of U.S. Provisional Application No. 60/233,392, filed Sep. 15, 2000, the disclosures of which are incorporated herein by reference. 

   FIELD OF INVENTION 
   This invention relates to an ice cube-making machine that is quiet at the location where ice is dispensed. 
   BACKGROUND OF INVENTION 
   Ice cube-making machines generally comprise an evaporator, a water supply and a refrigerant/warm gas circuit that includes a condenser and a compressor. The evaporator is connected to the water supply and to a circuit that includes the condenser and the compressor. Valves and other controls control the evaporator to operate cyclically in a freeze mode and a harvest mode. During the freeze mode, the water supply provides water to the evaporator and the circuit supplies refrigerant to the evaporator to cool the water and form ice cubes. During the harvest mode, the circuit converts the refrigerant to warm gas that is supplied to the evaporator, thereby warming the evaporator and causing the ice cubes to loosen and fall from the evaporator into an ice bin or hopper. 
   When installed in a location, such as a restaurant, where a small footprint is needed, ice making machines have been separated into two separate packages or assemblies. One of the packages contains the evaporator and the ice bin and is located within the restaurant. The other package contains the compressor and condenser, which are rather noisy. This package is located remotely from the evaporator, for example, outside the restaurant on the roof. The evaporator package is relatively quiet as the condenser and compressor are remotely located. 
   This two package ice cube-making machine has some drawbacks. It is limited to a maximum height distance of about 35 feet between the two packages because of refrigerant circuit routing constraints. Additionally, the compressor/condenser package weighs in excess of about 250 pounds and requires a crane for installation. Furthermore, service calls require the mechanic to inspect and repair the compressor/condenser package in the open elements, since it is typically located on the roof of a building. Due to inclement weather, it would be highly desirable to be able to work on the compressor in doors, since it is only the condenser that requires venting to the atmosphere. 
   During harvest mode, the condenser is bypassed so that refrigerant is supplied from the compressor in vapor phase to the evaporator. When the compressor is located a distance from the evaporator, the refrigerant tends to partially change to liquid phase as it traverses the distance, thereby affecting the efficiency warming or defrosting the evaporator. One prior art solution to this problem uses a heater to heat the vapor supply line. Another prior art solution locates a receiver in the same package as the evaporator and uses the vapor ullage of the receiver to supply vapor to the evaporator. Both of these solutions increase the size of the package and, hence, its footprint in a commercial establishment. 
   Thus, there is a need for a quiet ice cube-making machine that has a larger height distance between the evaporator and the condenser and a lighter weight for installation without the need for a crane. 
   There is also a need for an efficient way of providing vapor to an evaporator during harvest mode. 
   SUMMARY OF INVENTION 
   The ice cube-making machine of the present invention satisfies the first need with a three package system. The condenser, compressor and evaporator are located in separate ones of the packages, thereby reducing the weight per package and eliminating the need for a crane during installation. The compressor package can be located up to 35 feet in height from the evaporator package. For example, the evaporator package can be located in a restaurant room where the ice cubes are dispensed and the compressor package can be located in a separate room on another floor of the building, such as a utility room. This allows for service thereof to be made indoors, rather than outdoors as required by prior two package systems. The condenser package can be located up to 35 feet in height from the compressor package. For example, the condenser package can be located on the roof of the multistory building. 
   The evaporator package has a support structure that supports the evaporator. The compressor package has a support structure that supports the compressor. The condenser package has a support structure that supports the condenser. 
   The present invention satisfies the need for providing vapor to the evaporator during harvest mode by increasing the pressure and temperature of the refrigerant in the evaporator. This is accomplished by connecting a pressure regulator in circuit with the return line between the evaporator and the compressor. The pressure regulator limits flow, which increases pressure and temperature of the refrigerant in the evaporator. To achieve a small footprint of the evaporator package, the pressure regulator can be located in the compressor package. 

   
     BRIEF DESCRIPTION OF DRAWING 
     Other and further objects, advantages and features of the present invention will be understood by reference to the following specification in conjunction with the accompanying drawings, in which like reference characters denote like elements of structure and: 
       FIG. 1  is a perspective view, in part, and a block diagram, in part, of the quiet ice cube-making machine of the present invention; 
       FIG. 2  is a perspective view, in part, and a block diagram, in part, of an alternative embodiment of the quiet ice cube-making machine of the present invention; 
       FIG. 3  is a circuit diagram of a refrigerant/warm gas circuit that can be used for the quiet ice cube-making machine of  FIG. 1 ; 
       FIG. 4  is a circuit diagram of an alternative refrigerant/warm gas circuit that can be used for the quiet ice cube-making machine of  FIG. 1 ; 
       FIG. 5  is a circuit diagram of an alternative refrigerant/warm gas circuit that can be used for the quiet ice cube-making machine of  FIG. 2 ; and 
       FIG. 6  is circuit diagram of another alternative refrigerant/warm gas circuit that can be used for the quiet ice-cube making machine of FIG.  1 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIG. 1 , an ice cube-making machine  20  of the present invention includes an evaporator package  30 , a compressor package  50 , a condenser package  70  and an interconnection structure  80 . Evaporator package  30  includes a support structure  32  that has an upwardly extending member  34 . An evaporator  36  is supported by support structure  32  and upwardly extending member  34 . An ice bin or hopper  38  is disposed beneath evaporator  36  to receive ice cubes during a harvest mode. 
   Compressor package  50  includes a support structure  52  upon which is disposed a compressor  54 , an accumulator  56  and a receiver  40 . Condenser package  70  includes a support structure  72  upon which is disposed a condenser  74  and a fan  76 . It will be appreciated by those skilled in the art that support structures  32 ,  52  and  72  are separate from one another and may take on different forms and shapes as dictated by particular design requirements. It will be further appreciated by those skilled in the art that evaporator package  30 , compressor package  50  and condenser package  70  suitably include various valves and other components of an ice cube-making machine. 
   Interconnection structure  80  connects evaporator  36 , compressor  54  and condenser  74  in a circuit for the circulation of refrigerant and warm gas. Interconnection structure  80  may suitably include pipes or tubing and appropriate joining junctions. 
   Referring to  FIG. 2 , an ice-making machine  25  is identical in all respects to ice making machine, except that receiver  40  is disposed on support structure  32  in evaporator package  30  rather than in compressor package  50 . 
   Referring to  FIG. 3 , a circuit  82  is shown that may be used with the  FIG. 1  ice cube-making machine. Circuit  82  includes interconnection structure  80  that connects the components within compressor package  50  to the components within evaporator package  30  and to the components within condenser package  70 . In evaporator package  30 , evaporator  36  is connected in circuit  82  with a defrost valve  42 , an expansion valve  44 , a liquid line solenoid valve  45 , a drier  46  and an isolation valve  48 . In compressor package  50 , receiver  40 , compressor  54  and accumulator  56  are connected in circuit  82  with a filter  51 , a bypass valve  53 , a check valve  55  and an output pressure regulator  57 . In condenser package  70 , condenser  74  is connected in circuit  82  with a head pressure control valve  58 . Head pressure control valve  58  may alternatively be placed in compressor package  50 . It will be appreciated by those skilled in the art that evaporator package  30 , compressor package  50  and condenser package  70  may include other valves and controls for the operation of ice cube-making machine  20 . A heat exchanger loop  87  is in thermal relationship with the liquid refrigerant in accumulator so as to optimize the use thereof during the freeze cycle. 
   Referring to  FIG. 4 , a circuit  182  is shown that may be used with ice cube-making machine  20  of FIG.  1 . Circuit  182  includes interconnection structure  80  that connects the components within compressor package  50  to the components within evaporator package  30  and to the components within condenser package  70 . In evaporator package  30 , evaporator  36  is connected in circuit  182  with a defrost or cool vapor valve  142  and an expansion valve  144 . In compressor package  50 , receiver  40 , compressor  54  and accumulator  56  are connected in circuit  182  with a filter  151 , a bypass valve  153  and an output pressure regulator  157 . In condenser package  70 , condenser  74  is connected in circuit  182  with a head master or head pressure control valve  158 . A heat exchanger loop  187  is in thermal relationship with an output tube of accumulator  56  to optimize the use of liquid refrigerant in the accumulator during the freeze cycle. 
   It will be appreciated by those skilled in the art that evaporator package  30 , compressor package  50  and condenser package  70  may include other valves and controls for the operation of ice cube-making machine  20 . For example, ice-making machine  20  includes a controller  193  that controls the operations thereof including the activation of bypass solenoid valve  153  during the harvest cycle. Alternatively, a pressure switch  192  during harvest mode can activate solenoid valve  153 . 
   According to a feature of the present invention output pressure valve  157  operates to raise pressure and temperature of the refrigerant in evaporator  36  during ice harvesting. 
   During a freeze cycle, cool vapor valve  142  and bypass valve  153  are closed and expansion valve  144  is open. Refrigerant flows from an output  184  of compressor  54  via a line  185 , condenser  74 , head pressure control valve  158 , a line  186 , receiver  40 . Flow continues via heat exchanger loop  187 , a supply line  188 , filter  151 , expansion valve  144 , evaporator  36 , a return line  189 , accumulator  56 , output pressure regulator  157  to an input  190  of compressor  54 . Output pressure regulator  157  is wide open during the freeze cycle such that the refrigerant passes without any impact on flow. 
   During a harvest cycle, cool vapor valve  142  and bypass valve  153  are open and expansion valve  144  is closed. Refrigerant in vapor phase flows from the output of compressor  54  via either or both of bypass valve  153  or head pressure valve  158  through line  186  to receiver  40 . Flow continues via a vapor line  191 , cool vapor valve  142 , evaporator  36 , return line  189 , accumulator  56 , output pressure regulator  157  to input  190  of compressor  54 . 
   Output pressure regulator  157  operates during harvest to slow the flow and decrease pressure at input  190  to compressor  54 . This results in a higher pressure in evaporator  36  and higher temperature of the vapor in evaporator  36 . The higher temperature refrigerant in evaporator  36  enhances the harvest cycle. 
   Output pressure regulator  157  may be any suitable pressure regulator that is capable of operation at the pressure required in ice-making systems. For example, output pressure regulator may be Model No. OPR 10 available from Alco. 
   Referring to  FIG. 5 , a circuit  282  is shown that may be used with ice cube-making machine  25  of FIG.  2 . Circuit  282  includes interconnection structure  80  that connects the components within compressor package  50  to the components within evaporator package  30  and to the components within condenser package  70 . In evaporator package  30 , evaporator  36  and receiver  40  are connected in circuit  282  with a defrost valve  242 , an expansion valve  244 , a drier  246  and a check valve  248 . In compressor package  50 , compressor  54  and accumulator  56  are connected in circuit  282  with a head pressure control valve  258 . In condenser package  70 , condenser  74  is connected in circuit  282 . Head pressure control valve  258  may alternatively be placed in condenser package  70 . It will be appreciated by those skilled in the art that evaporator package  30 , compressor package  50  and condenser package  70  may include other valves and controls for the operation of ice cube-making machine  20 . 
   Ice cube-making machines  20  and  25  of the present invention provide the advantage of lightweight packages for ease of installation. In most cases, a crane will not be needed. In addition, the evaporator package is rather quiet in operation, as the compressor and the condenser are remotely located. Finally, the distance between evaporator package  30  and condenser package  70  is greatly enhanced to approximately 70 feet in height from the 35 feet height constraint of the prior art two package system. 
   Referring to  FIG. 6 , a circuit  382  is shown that may be used with ice cube-making machine  20  of FIG.  1 . Circuit  382  includes interconnection structure  80  that connects the components within compressor package  50  to the components within evaporator package  30  and to the components within condenser package  70 . In evaporator package  30 , evaporator  36  is connected in circuit  382  with a defrost or cool vapor valve  342  and an expansion valve  344 . In compressor package  50 , receiver  40 , compressor  54  and accumulator  56  are connected in circuit  382  with a filter  351 , a bypass valve  353 , a head master or head pressure control valve  358  and an output pressure regulator  357 . A heat exchanger loop  387  passes through accumulator  56  and is in thermal relationship with an output tube of accumulator  56  to optimize the use of liquid refrigerant in the accumulator during the freeze cycle. 
   It will be appreciated by those skilled in the art that evaporator package  30 , compressor package  50  and condenser package  70  may include other valves and controls for the operation of ice cube-making machine  20 . For example, ice-making machine  20  includes a controller  393  that controls the operations thereof including the activation of bypass solenoid valve  353  during the harvest cycle. Alternatively, a pressure switch  392  during harvest mode can activate solenoid valve  353 . 
   According to a feature of the present invention output pressure valve  357  operates to raise pressure and temperature of the refrigerant in evaporator  36  during ice harvesting. 
   During a freeze cycle, cool vapor valve  342  and bypass valve  353  are closed and expansion valve  144  is open. Refrigerant flows from an output  384  of compressor  54  via a line  385 , condenser  74 , head pressure control valve  358  and a line  386  to receiver  40 . Flow continues via heat exchanger loop  387 , a supply line  388 , filter  351 , expansion valve  344 , evaporator  36 , a return line  389 , accumulator  56 , output pressure regulator  357  to an input  390  of compressor  54 . Output pressure regulator  357  is wide open during the freeze cycle such that the refrigerant passes without any impact on flow. 
   During a harvest cycle, cool vapor valve  342  and bypass valve  353  are open and expansion valve  344  is closed. Refrigerant in vapor phase flows from the output of compressor  54  to a vapor line  391  via either or both of a first path that includes bypass valve  353  or a second path that includes head pressure valve  358  line  386  and receiver  40 . Flow continues via vapor line  391 , cool vapor valve  342 , evaporator  36 , return line  389 , accumulator  56 , output pressure regulator  357  to input  390  of compressor  54 . 
   Output pressure regulator  357  operates during harvest to slow the flow and decrease pressure at input  390  to compressor  54 . This results in a higher pressure in evaporator  36  and higher temperature of the vapor in evaporator  36 . The higher temperature refrigerant in evaporator  36  enhances the harvest cycle. 
   The present invention having been thus described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the present invention as defined in the appended claims.