IT201600122646A1 - REFRIGERATOR AND REGULATION METHOD - Google Patents

Description

REFRIGERATOR DISPENSER AND ADJUSTMENT METHOD

TECHNICAL FIELD

The present invention relates to refrigerators and more particularly to a refrigerator for dispensing cold drinks at supra-zero and sub-zero temperatures, as well as a relative method for regulating the operating temperatures above and below zero for two cooling tanks using a single refrigeration circuit.

BACKGROUND

Numerous refrigerators are known for dispensing drinks tapped from a tank at room temperature and cooled during dispensing in order to come out of the refrigerators at the temperature at which they are to be served. Such refrigerators are generally bulky in that they also enclose in their casing one or more distinct tanks for containing the drinks to be dispensed.

Other refrigerators, on the other hand, do not have built-in tanks, but suction pipes to be put in fluid communication with bottles or external drums at room temperature containing the drinks to be dispensed cold. These refrigerators are compact, because they do not require tanks inside the casing, and have a refrigeration circuit thermally coupled to pipes that connect a respective suction duct, connected to the bottle or drum, and a corresponding spout. dispensing the drink. Typically, there are several suction ducts and corresponding dispensing spouts for different drinks, for example essentially aqueous drinks such as carbonated drinks or fruit juices, which all come out at the same super-zero temperature. While they can replace soft drink bottles or drums with spirits bottles, these refrigerators are not suitable for serving spirits at the right temperature because they are not configured to refrigerate beverages at sub-zero temperatures.

It would be desirable to have a dispensing refrigerator capable of tapping from bottles and serving both drinks at above and below zero temperatures at the same time.

SUMMARY

In theory, the temperature of a coolant contained in a tank in which a food coil is immersed could be lowered, until it is below zero, to adequately cool the spirits. However, tests carried out by the applicant have surprisingly shown that such a resulting refrigerator is no longer suitable for dispensing soft drinks, such as fruit juices, which are almost completely aqueous drinks. Experimentally it was found that the water contained in the soft drinks tended to freeze too quickly, practically as soon as the drink came into contact with the food coil immersed in the tank, occluding the coil. The emergence of this unexpected problem has made it clear that such a simple solution is not feasible.

Through repeated attempts, the Applicant has verified that it is possible to produce a compact dispenser refrigerator, capable of delivering both drinks at a super-zero temperature and at a sub-zero temperature at the same time, using a single refrigeration circuit.

This excellent result was obtained by making a dispenser refrigerator with at least two distinct tanks: a first tank containing thermostated coolant at a superzero temperature, and a second tank containing thermostated coolant at a subzero temperature by heat exchange with a coil of a refrigeration circuit. The two tanks are in fluid communication so as to be able to thermostat the first tank by transferring with a pump, in a regulated manner, subzero coolant from the second tank to the first, moving a corresponding volume of coolant liquid from the first tank to the second tank to keep them unchanged. the filling levels of the tanks. In each of the two tanks a corresponding food coil is at least partially immersed through which a drink is pumped, which is cooled during delivery.

A method of regulating the supra-zero and sub-zero operating temperatures of coolant liquids in two distinct cooling tanks using a single refrigeration circuit is also disclosed.

The claims as filed form an integral part of this specification and are incorporated herein by express reference.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a basic diagram of a dispensing refrigerator according to a particular embodiment of the invention having four distinct ducts for dispensing beverages at four different temperatures.

DETAILED DESCRIPTION

Tests on prototypes carried out by the applicant showed quite unexpectedly that when a soft drink is pumped through a food coil immersed in a coolant at a sub-zero temperature, the water in the drink freezes so quickly that it clogs the coil, preventing delivery. This unexpected problem led to the design of a dispenser refrigerator with two cooling tanks: a first tank containing coolant at a nominal temperature above zero (hereinafter called "cold tank"), and a second tank containing coolant at a nominal temperature below zero (hereinafter called "cold tub").

The dispensing refrigerators of the present disclosure have two tanks and at least two coils for food, each immersed in the respective tank, for delivering drinks at above zero and below zero temperatures, respectively. In order to keep the dimensions compact and not to increase production costs by installing two refrigeration circuits, the dispenser refrigerator of this disclosure is configured so that the two tanks are kept at their respective operating temperatures using a single refrigeration circuit.

Figure 1 shows a schematic diagram of a dispenser refrigerator according to this disclosure. The meaning of the different components labeled with reference numbers is summarized in the following table:

1 Compressor

2 Filter

3 Condenser with fan

4 Tank liquid transfer pump

5 Coolant cooling coil

6 Stainless steel coil for the passage of food liquids, large tank A

7 Stainless steel coil for the passage of food liquids, small tank B

8 Overflow pipe for the passage of coolant from tank A to tank B 9 Filling pipe tank A

10 Stainless steel coil for the passage of food liquids, large tank A

11 Stainless steel coil for liquid food passage small tank A

12 Peristaltic pumps

13 Product dispensing spouts

14 Tubes (for food) for product suction

15 220/24 V power supply

16 Small pumps for moving (stirring / stirring) liquid in the tanks

17 Digital thermostats to set the temperature of the coolant in the tanks

18 Buttons for dispensing

19 PLC for electronic control

A Cold tank at supra-zero temperature

B Frosty tub at sub-zero temperature

The "freezing" tank B is in fluid communication with the "cold" tank A through the overflow pipe 8, which connects the two tanks so that when a certain amount of cooling fluid is transferred from the freezing tank B to the cold tank A through the filler pipe, the same amount of coolant is displaced in the opposite direction.

The cooling coil 5 is immersed in the coolant of the freezing tank B to cool it to a nominal operating temperature below zero, for example -10 ° C.

The coolant of the cold tank A is kept at a low temperature but above zero, for example 1 ° C, without duplicating the refrigeration circuits with a consequent increase in manufacturing costs. A transfer pump 4 draws a quantity of liquid from the freezing tank B and mixes it with the (warmer) liquid of the cold tank A, and at the same time causes an equal quantity of liquid to pass from the cold tank A to the freezing tank B. This the exchange of liquids between the two tanks continues until the desired over-zero nominal operating temperature is reached in the cold tank A, measured by the thermostat 17A. In the meantime, the cooling coil 5 cools the liquid in the freezing tank B so that the nominal operating temperature below zero is kept constant, measured by the thermostat 17B.

A first food coil 6, intended for dispensing spirits to be served icy, is immersed in the liquid of the icy tank B and is connected on one side to a suction pump 12-1 from a bottle, and on the other side to a corresponding dispensing spout 13-1. When a spirit has to be dispensed, by pressing a button 18 (or, alternatively, by lowering a lever) of the refrigerator of this disclosure, the pump 12-1 is activated, for example a peristaltic pump, which sucks a portion of spirits from the bottle and forces the spirits to pass through the first coil 6, in which the heat exchange with the refrigerant fluid takes place, and to exit from the relative spout 13-1. The length of the first coil 6 and the flow rate of the first pump 12-1 are such as to cool the portion of spirits during transit, so as to exit the spout at a temperature close to the nominal sub-zero operating temperature of the liquid in the freezing tank B. The cooling of the tapped portion of spirits will lead to a corresponding heating of the liquid in the freezing tank B, promptly compensated by the cooling coil 5 which will re-establish the desired sub-zero operating temperature.

Figure 1 also shows a second coil for food 7, optional or alternative to the first, of shorter length than the first coil 6, connected to a second pump 12-2 and to the respective delivery spout 13-2. The second coil 7, being immersed in the freezing tank B, is also intended to cool the spirits and not the soft-drinks, as the latter would freeze rapidly obstructing it. Since the second coil 7 is shorter, the spirits pumped through it will be dispensed at a subzero temperature higher than the dispensing temperature of the spirits coming out of the first spout 13-1.

Similarly, in the cold tank A there is a third coil for food 10 and / or a fourth coil for food 11 shorter than the third coil 10, connected respectively to a third pump 12-3 and to a fourth pump 12-4 and to respective dispensing spouts 13-3 and 13-4. These food coils 10 and 11 are immersed in coolant at super-zero operating temperature and therefore can be used to cool soft drinks, which freeze at about 0 ° C. As for the first coil 6, the length of the third coil 10 and the flow rate of the third pump 12-3 are established to cool the portion of soft-drink during transit, so as to make it come out of the spout at a temperature close to the nominal temperature. operating surplus of the liquid in the cold tank A. Conveniently, the length of the third coil 10 and the flow rate of the third pump 12-3 will coincide respectively with the length of the first coil 6 and with the flow rate of the first pump 12-1.

Similarly for the fourth coil 11, optional or alternative to the third coil 10, similar observations - mutatis mutandis - apply to those made for the second coil 7.

As the soft drink passes through the third (fourth) coil 10 (11), the coolant in the cold tank A will heat up. This temperature increase will be detected by the sensor 17A and the control unit 19 will command the pump 4 to transfer sub-zero coolant from tank B to tank A through the filling pipe 9 and until the above-zero nominal operating temperature is re-established. As the sub-zero coolant passes from tank B to tank A, an equal volume of super-zero coolant will be moved from tank A to tank B, through the overflow pipe 8, substantially concentric with the fill pipe 9, keeping the refrigerant levels unchanged. in the two tanks. This will cause an increase in the temperature of the liquid in the freezing tank B, which will be readily compensated by the cooling coil 5 until the temperature sensor 17B detects that the nominal sub-zero operating temperature has been re-established. Figure 1 also shows optional pumps 16, one for each tank, to move the coolant into the respective tanks to make the temperature uniform.

In the illustrated embodiment, the tanks A and B are stacked one on top of the other so that the machine does not extend in width, with consequent problems of overall dimensions, but in height. However, according to another less preferred embodiment, the tubs A and B are side by side instead of stacked inside the machine casing.

With the dispenser refrigerator shown in figure 1, it is therefore possible to dispense both spirits at sub-zero temperatures and soft-drinks at super-zero temperatures using a single cooling circuit. By dimensioning the length of the coils for food and the flow rate of the relative pumps, it is possible to establish the temperature of the dispensing of the beverages with respect to the temperature of the coolant in which the coils for food are immersed.

Optionally, the temperatures in the freezing tank B and in the cold tank A can be independently adjusted: in the first case it is sufficient to adjust the temperature of the cooling coil 5; in the second case, it is necessary to act on pump 4 to move liquid from tank B to tank A.

According to an embodiment, the cold tank A contains coolant at a temperature of 0.5 ° C to 1.5 ° C, more preferably about 1 ° C, the cold tank B contains coolant at a temperature from -11 ° C from - 8 ° C, more preferably about -10 ° C.

Tests on different prototypes carried out by the applicant have shown that optimal results are obtained with tanks from 15 liters to 20 liters, 18 liters each, filled with antifreeze liquid such as glycol (non-toxic) or denatured alcohol at 15% - 20%. The heat capacity of all the coolant will be such that by cooling a glass of beverage initially to room temperature, the temperature of the coolant will increase by a small fraction of a degree. It is also possible to use larger tanks, but this seems less preferable because a greater capacity of the two tanks would be detrimental to the overall dimensions of the dispenser refrigerator. Conversely, less capacious tanks can still be used, in particular for domestic or sporadic use of the dispenser refrigerator, but could lead to significant variations in the dispensing temperature when a relatively large number of glasses must be filled practically uninterrupted, as happens for example in bars. or in the canteens.

Tests carried out by the applicant have shown that, by using 5 and 10 food coils from 7 meters to 10 meters long, more preferably 8 meters, it is possible to refrigerate beverages to a temperature of approximately four degrees higher than the temperature of the refrigerant fluid in which the coils they are immersed, pumping them with a flow rate between 40 and 45 liters / hour. This means that, if the freezing tank B is at a temperature of -10 ° C and the cold tank is at a temperature of 1 ° C, then from the spouts 13-1 and 13-3, drinks will come out respectively at temperatures of about - 6 ° C (suitable for spirits) and 5 ° C (suitable for soft drinks). Optionally or alternatively, coils for food 7 and 11 can be used, about 3 to 5 meters long, more preferably 4 meters, to cool drinks, always pumping them (with pumps 12-2 and 12-4) with a flow rate between 40 and 45 liters / hour, at temperatures respectively about nine degrees higher and about six degrees higher than the temperature of the refrigerant fluid in which the food coils are immersed. In this way, drinks will be dispensed from spouts 13-2 and 13-4 at temperatures of approximately -1 ° C (suitable for bitters) and 8 ° C (suitable for wines) respectively.

In theory, it would be possible to use coils for food shorter than those indicated above and correspondingly reduce the flow rate of the pumps 12 in order to obtain the same dispensing temperatures indicated above, but in this way the drinks would come out more slowly so that would take longer to fill a glass.

Similarly, the flow rate of the pumps 12 could be increased in order to have a faster service, correspondingly increasing the length of the coils immersed in the coolant liquid in order to have the same delivery temperatures as in the previous cases. In this case, however, to contain longer coils, the capacity of the tanks should also be increased, consequently increasing the total size of the refrigerator. More generally, each tank can also contain more than two coils of different length, connected on one side to respective pumps for food, for example peristaltic pumps, and on the other side to relative delivery spouts. If the pumps suck liquids with the same flow rate, there will be several different spouts capable of delivering drinks at different temperatures above zero at the same time, if the coils for food are immersed in cold tank A, or below zero, if the coils for foods are immersed in the freezing tub B.

Conveniently, the coils for food are connected to the suction pipes 14 of the drinks and to the dispensing spouts by means of fittings installed outside the tanks, preferably by means of quick couplings, which do not allow either the accidental outflow of the drinks or the entry of coolant. .

Figure 1 shows a classic refrigeration circuit with a compressor 1 and a condenser 3, but it is possible to simply adapt the scheme shown to use an absorption refrigeration cycle (so-called Einstein refrigerator). Regardless of the type of refrigeration cycle used, it is important that the cooling coil 5 at sub-zero temperature is immersed in the coolant of the freezing tank B.

In the illustrated embodiment, the transfer pump 4 is immersed in the freezing tank B and pumps the coolant liquid from the tank B to the tank A, while the liquid from the tank A is transferred to the tank B by means of an overflow pipe. This embodiment is preferred due to its constructive simplicity, however other solutions are possible. For example, the pump 4 could be external to the freezing tank B and connected to the tanks A and B by means of closed-loop pipes in order to move the coolant liquid from one tank to the other while keeping the filling levels of both of them constant.

The dual configuration of the one illustrated in figure 1 is also possible, i.e. with the freezing tank B stacked above the cold tank A and the transfer pump 4 installed in the cold tank A: in this case the overflow pipe 8 will allow the liquid to be transferred. from freezing tank B to cold tank A when pump 4 will displace coolant from cold tank A.

In theory, it is also possible to add other tanks by making sure that each of the additional tanks is connected to the freezing tank B exactly like the cold tank A, so as to increase the number of food coils immersed in the cooling fluid and therefore the number of dispensers. different drinks. Clearly, such a solution will increase the overall dimensions, so it could be suitable for a fixed installation in a dining room or in any case where there are no particular space restrictions.

Advantageously, the dispensing refrigerator of this disclosure is equipped with buttons 18 (or levers), one for each food coil, for regulating the quantity of beverage to be dispensed. According to an embodiment, the control unit 19, which for example can be a PLC, will be programmed so that, each time a button 18 is pressed, the respective pump 12 is commanded to dispense a predefined quantity of drink (for example example 5 cl or 10 cl). Alternatively, dispensing can take place continuously as long as the user keeps the button pressed.

The dispenser refrigerator of this disclosure can be equipped with suitable connections to a hot coffee or tea machine to serve an iced coffee or iced tea, cooling a freshly brewed hot coffee or tea practically in real time. Tests carried out with a working prototype have shown that the dispenser refrigerator of this disclosure is capable of serving freshly brewed coffee cold at about 6 ° C in a brewing time of 6-8 seconds, from the moment in which the hot coffee is produced by the coffee machine. Consequently, it is possible to prepare an iced coffee (or even an iced tea) at the moment without having to add ice and shake it, as is the case now, thus diluting the drink with water and altering its taste.

Claims (10)

CLAIMS 1. Dispenser refrigerator to cool and dispense at the same time a beverage at a supra-zero temperature and a beverage at a sub-zero temperature, comprising: a single refrigeration circuit comprising a cooling coil (5) configured to cool to a sub-zero temperature; a first tank (A) filled with coolant; a second tank (B) filled with coolant in which said cooling coil (5) is immersed; a transfer pump (4), connected by pipes to the first tank (A) and to the second tank (B) and configured to move the coolant from the second tank (B) to the first tank (A) or vice versa while maintaining the volumes of coolant unaltered in each of said tanks (A, B); a control unit (19), configured to control said transfer pump (4) to thermostat the coolant in the first tank (A) at a nominal above zero operating temperature; at least one first line for dispensing beverages at super-zero temperatures, comprising: - a respective pump for food (12-3; 12-4) which can be connected to a bottle of a beverage to be cooled and to be dispensed at a superzero temperature, - a respective coil (10) for food immersed in the coolant of the first tank (A) and in fluid communication with the respective food pump (12-3; 12-4), - respective dispensing terminals (13-3; 13-4) of the beverage to be dispensed at a superzero temperature, in fluid communication with the respective coil (10; 11); at least one first line for dispensing beverages at sub-zero temperatures, comprising: - a respective pump for food (12-1; 12-2) which can be connected to a bottle of a beverage to be cooled and to be dispensed at a sub-zero temperature, - a respective coil (6; 7) for food immersed in the coolant of the second tank ( B) and in fluid communication with the respective food pump (12-1; 12-2), - respective dispensing terminals (13-1; 13-2) of the beverage to be dispensed at a sub-zero temperature, in fluid communication with the respective coil (6; 7). 2. Dispensing refrigerator according to claim 1, comprising a second line for dispensing beverages at super-zero temperatures identical to said first line but with a respective coil for food (11) shorter than the coil for food (10) of the first dispensing line of drinks at supra-zero temperatures. 3. Dispensing refrigerator according to claim 1, comprising a second line for dispensing beverages at subzero temperatures identical to said first line but with a respective food coil (7) shorter than the food coil (6) of the first dispensing line of drinks at sub-zero temperatures. Dispenser refrigerator according to one of claims 1 to 3, wherein: the first tank (A) is stacked above the second tank (B) and is in fluid communication with the second tank (B) through a configured overflow pipe to let coolant flow from the first tank (A) to the second tank (B) when a maximum filling level is reached; the transfer pump (4) is configured to suck coolant from the second tank (B) and pump it into the first tank (A). 5. Dispensing refrigerator according to claim 1 to 4, wherein said single refrigeration circuit is configured to implement a compression or absorption refrigeration cycle. 6. Dispensing refrigerator according to claim 1 to 5, in which each of said first (A) and second (B) tanks contains about 18 liters of thermostated refrigerant liquid respectively at the nominal above-zero operating temperature between 0.5 ° C and 1.5 ° C and at a nominal sub-zero operating temperature between -11 ° C and -8 ° C. 7. Dispensing refrigerator according to one of claims 1 to 6, wherein: said food pumps are peristaltic pumps with a flow rate of between 40 and 45 liters / hour; the coils of the first beverage dispensing lines at temperatures above zero and below zero respectively have a length of about 8 meters. 8. Dispensing refrigerator according to one of claims 2 or 3, wherein: these pumps for food are peristaltic pumps with a flow rate between 40 and 45 liters / hour; the coils of the second beverage dispensing lines at temperatures above zero and below zero respectively have a length of about 4 meters. 9. Dispensing refrigerator according to one of claims 1 to 8, comprising a stirring pump (16) of coolant liquid immersed in each of said first (A) and second (B) tanks. 10. A method of regulating supra-zero and sub-zero operating temperatures of a dispensing refrigerator comprising: a single refrigerant circuit comprising a cooling coil (5) configured to cool to a sub-zero temperature, a first tank (A) filled with coolant, a second tank (B) filled with coolant in which said cooling coil (5) is immersed, a transfer pump (4), connected by pipes to the first tank (A) and to the second tank (B) and configured to move the coolant from the second tank (B) to the first tank (A) or vice versa while maintaining the volumes of coolant unaltered in each of said tanks (A, B), an overflow pipe configured to let coolant flow from the first tank (A) to the second tank (B) or vice versa, a control unit (19), configured to control said transfer pump (4), said method comprising the following operations: comparing a temperature of the coolant in the first tank (A) with a nominal above zero operating temperature; if the temperature of the coolant in the first tank (A) exceeds the nominal above-zero operating temperature, pump with said transfer pump (4) coolant liquid from the second tank (B) into the first tank (A) or vice versa, letting the coolant flow from the first tank (A) to the second tank (B) or vice versa through the overflow pipe until the above-mentioned nominal operating temperature in the first tank (A) is reached; compare a temperature of the coolant in the second tank (B) with a nominal operating temperature below zero; thermostating the temperature of the coolant in the second tank (B) at the nominal operating temperature below zero by means of this single refrigerant circuit.