Dual temperature refrigeration system

A dual temperature refrigeration system which includes a first and second evaporator coil which chills water and freezes water within a tank for producing carbonated water. A restrictor tube is connected between the first evaporator coil and the second evaporator coil for reducing the temperature of the refrigerant flowing through the second evaporator coil. When the demand occurs for chilled water, a switch provided in a by-pass conduit extending around the second evaporator coil is opened, permitting the refrigerant to by-pass the second coil which is used for producing an ice bank in the carbonator.

BACKGROUND OF THE INVENTION 
Heretofore, normally when producing carbonated water, chilled water from an 
exterior source was fed into the carbonator so that carbon dioxide could 
be bubbled therethrough for producing the carbonated water. Normally, a 
separate cooling system was utilized for producing this chilled water. It 
is desirable when making carbonated water that the water being fed to the 
carbonating tank be approximately 34.degree. F. since the cooler the 
water, the better the carbonation. Normally, compressor systems utilized 
in cooling water have carbonating systems which only bring the water down 
to 34.degree. F. because of the tolerance of the controls. If the controls 
of the condensor were set to a temperature of approximately 32.degree. F., 
often, the water would freeze because of the tolerance of the control. 
This, of course, would prevent carbonated water from being produced. 
Furthermore, usually a separate refrigeration system would be utilized for 
dispensing cold water. 
Attempts have been made to develop systems that produce different 
temperatures within a single system, for example, for cooling water and 
for producing ice. Examples of such devices are disclosed in U.S. Pat. 
Nos. 3,783,630; 2,156,668; 2,605,621; 2,653,014; 3,739,842 and 2,322,627. 
Other patents developed during a search include U.S. Pat. Nos.2,396,460; 
2,554,638 and 4,036,621. 
SUMMARY OF THE INVENTION 
The device constructed in accordance with the present invention provides a 
means of producing a dual temperature refrigeration unit with a single 
refrigeration system. 
In one particular embodiment, the system is capable of producing cool or 
cold water for being dispensed through a spicket and also cooling water to 
a lower temperature for maximizing carbonation in a carbonating tank. Of 
course, it is to be understood that there are many different applications 
for the dual temperature refrigeration system and the carbonating tank is 
merely one example of a use for such a system. In the carbonator tank 
system, a stainless steel tank is provided and has a diffuser therein 
through which carbon dioxide is fed for bubbling through water contained 
in the tank. In order to maximize the carbonation of the water in the 
tank, it is important that the temperature of the water in the tank be 
maintained at approximately 32.degree. F. to 32.5.degree. F. This is 
accomplished by building up a layer of ice on the inner wall of the tank. 
A temperature sensing probe is positioned closely adjacent the layer of 
ice for controlling the flow of refrigerant through an evaporator coil 
extending around the outer periphery of the tank. It is to be understood, 
of course, that the evaporator coil could be positioned along the inner 
wall of the tank if desired. The probe positioned in the tank controls the 
thickness of the ice buildup within the tank. 
In order to increase the efficiency of the carbonating system, it is 
desired that the water entering the carbonating tank be chilled to a 
temperature of approximately 34.degree. F. before entering the tank. This 
is accomplished by a second cold water evaporator coil that is positioned 
concentric to the inner freezing evaporator coil and separated therefrom 
by a layer of insulation. 
The water that is to be chilled is fed through another coil that is in 
surface contact with the evaporator cold water coil so that as the water 
is fed through the cold water coil, it is chilled to approximately 
34-35.degree. F. A second temperature sensor is positioned adjacent the 
outer surface of the cold water coil for selectively turning on the 
condenser for feeding refrigerant through the evaporator cold water coil 
to ensure the desired temperature of cold water. 
Accordingly, it is an important object of the present invention to provide 
a dual temperature refrigeration unit for freezing and chilling liquids. 
Another important object of the present invention is to provide a simple 
and efficient device for producing liquids of two different temperatures. 
Another important object of the present invention is to provide a single 
refrigeration system for producing fluids or liquids of two different 
temperatures.

DESCRIPTION OF A PREFERRED EMBODIMENT 
Referring in more detail to the drawings, there is illustrated a dual 
temperature refrigeration unit constructed in accordance with the present 
invention which includes a compresser unit generally designated by the 
reference character 10 constructed in any conventional manner. The 
compressor unit 10 includes a compresser 12, a fan 14, and a condenser 16. 
The output of the condenser is fed through a liquid line drier 18 to a 
wound capillary tube 20. As the liquid reaches the capillary tube 20, it 
goes through an evaporator cold water coil 22. This lowers the temperature 
of the gas flowing through the coil and, as a result, the temperature of 
the coil is approximately 34.degree. for cooling water. The output of the 
cold water coil 22 is connected to a T-joint 24. One leg of the T is 
connected through a small bore restrictor 26 and the other leg of the T is 
connected to a by-pass conduit 28 which has a solenoid valve 30 interposed 
therein. This is a normally closed solenoid valve which is selectively 
opened and closed by a thermostat 32 which will be more fully described 
below. 
The other end of the small bore restrictor tube 26 is connected to an end 
of another evaporator coil 34 which is provided for lowering the 
temperature of the surrounding medium even further than the temperature 
drop obtained by the cold water evaporator coil 22. The other end of the 
evaporator coil 34 is connected to one leg of a T 36. The other leg of the 
T 36 is connected by means of a tube 38 to the output side of the solenoid 
valve 30. The third leg of the T 36 is connected by a return conduit 40 to 
a suction line accumulator. A suction line accumulator 42 ensures that all 
liquid coming through tube 40 is maintained in the suction line 
accumulator allowing only gas vapor to be fed back to the compressor. It 
is to be understood, of course, that you do not want liquid to be fed back 
to the compressor. 
Referring now, in particular, to FIG. 1 of the drawing, the compressor unit 
10 is carried in the housing 46 positioned alongside the carbonating and 
beverage dispensing device. A carbonating tank 48 is centrally located 
within a housing 50 and has a line connected to the top thereof for 
receiving carbon dioxide. The line 52 transports the carbon dioxide to the 
bottom of the carbonator tank through a diffuser 54 for being bubbled 
through water carried within the tank 48. Water entering the tank 48 is by 
means of copper tube 56a. The carbonated water that is produced in the 
tank is removed from the tank through a conduit 58 which extends to the 
bottom of the tank. A dispensing valve 60 is provided for dispensing the 
carbonated water from the tank through a syrup mixing valve 62 for 
producing a carbonated drink. The particular valve mechanism for 
controlling the flow of water to and from the tank automatically is not 
disclosed since such is a conventional item. One particular valving 
mechanism that could be used is disclosed in U.S. Pat. No. 3,637,197 
issued to James L. Hudson on Jan. 25, 1972. 
The evaporator coil 34 extends around the outside wall of the tank 48 and 
as the refrigerant passes therethrough, it causes a layer of ice to be 
formed on the inner wall of the tank which extends radially inwardly 
approximately one inch. A thermostat 64 is positioned closely adjacent the 
layer of ice on the inner wall of the carbonator for controlling the 
operation of the compressor unit 10 for maintaining the thickness of the 
ice at approximately one inch. 
The main evaporator coil 22 is concentrically wound around the evaporator 
coil 34 and is spaced therefrom by means of a layer of insulation 35. This 
evaporator coil is constructed of relatively flat tubing so as to increase 
the efficiency of heat exchange between its surface and the surface of 
another flat coil 56 through which water flows for being pre-cooled prior 
to being fed into the carbonator tank through tube 56a or dispensed 
through an exterior dispensing valve 68. A thermostat 32 is positioned 
alongside the water coil 56 for selectively opening and closing the 
solenoid valve shown in the circuit of FIG. 2. It is noted that water from 
any suitable source is fed to the system through a line coming out of the 
bottom of the carbonator. 
In operation, another thermostat 64 carried within the tank indicates that 
the water provided in the tank is above 32.degree. to 32.5.degree. F. due 
to the melting of the ice bank therein causing the compressor unit to be 
turned on. When the compresser unit 10 is turned on, liquid Freon is fed 
through the capillary tube 20 and exits therefrom in the main evaporator 
coil 22. This causes the water carried in the coil 56 to be chilled to 
approximately 34.degree. F. It is noted that during this time, the 
solenoid valve 30 is opened and the evaporator coil 34 is more or less 
by-passed because of restrictor tube 26. Upon the water in the tube 56 
reaching its desired temperature of approximately 34.degree. F., the 
thermostat 32 de-energizes the solenoid valve 30 closing the solenoid 
valve 30. When the solenoid valve 30 is closed, the Freon exiting from the 
cold water evaporator coil 22 passes through a small bore restrictor 26 to 
the evaporator coil 34 carried on the inner wall of the tank 48 for 
lowering the temperature of the water in the tank so as to build up the 
ice layer in the tank 48 to its desired thickness of approximately one 
inch. Upon the temperature of the water carried within the tank 48 
reaching approximately 32.degree. F., the thermostat positioned within the 
tank cuts off the compressor unit indicating that all units are satisfied, 
that is, there is sufficient ice buildup on the inner wall of the tank and 
water carried within the coil 56 is approximately 34.degree. F. As the 
water is utilized causing the temperature of the water in the coil 56 to 
rise above a predetermined level, the thermostat 32 turns on the 
compressor unit and energizes solenoid valve 30 opening the conduit 28 so 
that the main flow of refrigerant by-passes the refrigeration coil 34 and 
only flows through the evaporator coil 22 for cooling the water. 
As a result of the thermostat 32 operating both the solenoid valve 30 and 
the compresser unit 10, the water flowing through tube 56 is maintained at 
approximately 34.degree. F. and the condition of maintaining it at this 
temperature must first be satisfied before the refrigerant can be fed 
through the evaporator coil 34 for building up the ice layer within the 
tank. 
While the dual temperature refrigeration system has been described above in 
connection with a carbonator it is to be understood that it could be used 
in other situations where dual temperature is needed such as for chilling 
beer in a cooler at one temperature and dispensing it at another 
temperature. 
In one particular embodiment, the restrictor tube 26 is 18" long and has an 
inside diameter of 0.064 inches. The restrictor tube is seven feet long 
and has an inside diameter of 0.05 inches. The evaporator coil 22 is made 
of 3/8 inch tubing and is approximately twenty feet long. 
While a preferred embodiment of the invention has been described using 
specific terms, such description is for illustrative purposes only, and it 
is to be understood that changes and variations may be made without 
departing from the spirit or scope of the following claims.