JPS5844188B2 - beverage chiller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is used in vending machines or dispensers for soft drinks, beer, etc., and allows the beverage to be passed through a cooling pipe provided in a cooling water tank together with an evaporator of a refrigerator. The present invention relates to a beverage cooling device that cools beverages.

This type of beverage cooling device is known as a so-called ice bank, in which an ice layer of a suitable thickness is formed on the evaporator and the cooling capacity of the cooling water is increased by the latent heat of the ice.

The thickness of the ice layer in the ice bank is determined based on the continuous sales capacity of the vending machine or dispenser.
In the case of a soft drink vending machine, the amount of ice is determined by considering how many kilograms of ice are required to continuously sell the number of cups of beverages corresponding to the maximum storage amount of syrup at a specified beverage temperature.

Therefore, if the thickness of the ice layer is more than the specified value, it is wasteful, and if it is less than the specified value, the cooling capacity will be insufficient in the case of the above-mentioned continuous sale, and all the ice will melt during the sale.

The thickness of the ice layer is usually around 30 cm. Conventionally, the ice layer thickness is generally controlled by placing an electrode near the evaporator.

In other words, multiple electrodes are arranged at predetermined intervals in the direction of ice growth, and the electrical resistance between the electrodes changes as the electrodes become covered in ice or immersed in water due to ice growth or melting. Change the electrical output of the electrode circuit using
The refrigerator is stopped and started.

However, controlling the ice layer thickness using the electrode method requires a complicated electrode circuit and is therefore expensive.

Here, attempts have been made to control the operation of refrigerators using thermostats that are originally used for temperature control.

This involves placing the temperature-sensing part of the thermostat near the evaporator so that the ice layer is surrounded by ice after it forms, and operating the thermostat at the ice temperature at which the ice layer grows to a predetermined thickness, for example -10°C. This will stop the refrigerator.

However, this method has the following problems.

In other words, the ice layer is surrounded by water at 0°C, and the specific heat of ice is less than % of water, so when the refrigerator is stopped, the temperature of the ice immediately rises to 0°C, and even if the thermostat is turned back on, the ice temperature will rise to 0°C. If the temperature is kept at -0.5°C, operation of the refrigerator will be resumed within a short time.

As a result, the growth rate exceeds the melting rate of the ice layer, and the ice layer becomes thicker and thicker, until all the water in the tank freezes.

On the other hand, set the reset temperature of the thermostat to 0°C or higher, for example +
If the water temperature is kept at 0.5℃, the refrigerator will not restart unless all of the water in the water tank has melted and the water temperature in the water tank has risen to +0.5℃, so there is no shortage of heat capacity when continuously supplying beverages. Come.

The problem with controlling the ice layer thickness using the thermostat method stems from the fact that the thickness of the ice layer is not directly controlled as with the electrode method, but is indirectly controlled by sensing the temperature of the ice. Therefore, practical control cannot be achieved unless the thermostat return point is delayed by appropriate means.

This invention was made under these circumstances,
It is an object of the present invention to provide an inexpensive beverage cooling device that uses a thermostat to achieve desired ice layer thickness control in an ice bank.

In order to achieve this objective, this invention locally guides heat to the vicinity of the temperature sensing part of the thermostat and locally increases the temperature of the temperature sensing part even though ice remains on the evaporator surface. , the upper temperature limit at which the thermostat operates (
This allows the thermostat to set the return temperature (return temperature) to 0° C. or higher, thereby successfully delaying the return timing of the thermostat to an appropriate degree.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment. FIG. 1 shows a schematic diagram of a beer dispenser equipped with a beverage cooling device of the present invention.

In the beer dispenser 1, a high-temperature, high-pressure gas refrigerant discharged from an electric compressor 2 of a refrigerator is guided through a compressor outlet pipe 3 to a condenser 4, where it is cooled by an electric fan 5 and liquefied.

After this liquefied refrigerant exits the condenser 4, the capillary tube 6
The liquid passes through the evaporator 7 and is evaporated.

The low pressure gas refrigerant is then returned to the compressor 2 through the compressor inlet pipe 8 and compressed again.

The evaporator 7 is configured as a vertically cylindrically wound helical tube and is arranged in cooling water 10 in a cooling water tank 9 .

As the refrigerator operates, the temperature of the cooling water gradually decreases to 0° C., and as the refrigerator continues to operate, an ice layer 11 begins to form on the surface of the evaporator.

This ice layer 11 gradually grows and becomes thicker, and its thickness is controlled by stopping and starting the electric compressor 2 using a thermostat 12, as will be explained in detail later.

The temperature sensing part 12a of the thermostat is placed near the evaporator surface where an ice layer is formed.

In the water tank 9, a beverage cooling pipe 13 is arranged directly below the evaporator 7.

The beverage cooling pipe 13 is a spiral pipe wound flat along the bottom surface of the water tank 9, and one end is connected to a dispense valve 14 attached to the upper part of the dispenser body, and the other end is connected to a pipe joint 15 attached to the lower part of the dispenser body. It is connected to the.

Note that a stirring device (not shown) is provided in the tank to constantly circulate the water in the tank.

To take out the cooled beer using the beer dispenser 1, proceed as follows.

That is, as implied in Figure 1, carbon dioxide gas cylinder 1
The beer barrel 17 to which carbon dioxide gas pressure has been applied in step 6 is connected to the cooling pipe 13 via the joint 15, and the dispense valve is opened.

As a result, the beer pushed out of the beer barrel by carbon dioxide gas pressure passes through the cooling pipe 13, and the 0°C cooling water 1 in the water tank
It is cooled to an appropriate temperature by heat exchange with 0 and poured from the dispense pulp 14 into a pot.

In the illustrated embodiment, the thermostat includes a tongue set;
As shown in FIGS. 2 and 3, the temperature sensing part 12a, which is formed into a hollow cylindrical shape by spirally winding a heat sensitive tube, is attached to the evaporator 7 by a mounting bracket 18. As shown in FIGS.

A tube 19 made of a heat-insulating material such as soft vinyl chloride and having an inner diameter approximately equal to the outer diameter of the temperature-sensing section 12a is attached to the temperature-sensing section 12a.

A U-shaped portion at one end of the mounting bracket is fitted so as to grip the temperature-sensing portion 12a from above the tube, and a U-shaped portion at the other end of the mounting bracket is fitted into the spiral pipe portion of the evaporator.

A small diameter copper rod 20 is inserted into the hollow part of the temperature sensing part 12a.

The upper end of the copper rod 20 is tied to a liquid reservoir 8a for gas-liquid separation provided in a portion of the compressor return pipe 8 with a clasp 21, and the lower end is in contact with a temperature sensing part.

Now, the cooling water 10 is at the level indicated by the reference numeral in FIG. 2, and in this case, the upper end of the heat insulating tube 19 protrudes above the water surface as shown.

Since both ends of the insulating tube are open, cooling water can flow inside and outside the tube.

It is assumed that the ice layer 11 on the surface of the evaporator grows to the position indicated by the two-dot chain line in the figure.

Now, the operation of controlling the ice layer thickness in the beverage cooling device of the present invention will be explained below.

In Figure 4, the thickness H of the ice layer on one side from the evaporator surface is H
1 and H3.

It is now assumed that the refrigerator is being operated and the cooling water 10 has gone from room temperature to an ice layer thickness of H2.

The temperature of the ice surface is 0°C, which is the same as the water temperature, but the temperature distribution within the ice layer is as shown in C2 in the figure, and the temperature near the evaporator surface is 20°C.

At this time, if the temperature near the temperature sensing part of the thermostat at a distance of S from the evaporator surface is 14 degrees Celsius, and the lower limit operating temperature of the thermostat is set to 18 degrees Celsius, the refrigerator will continue to operate. .

After that, H reaches H3, the temperature distribution becomes C3, and at that time, if the temperature near the temperature sensing part reaches 18°C, the thermostat is activated and the refrigerator is stopped.

When the refrigerator stops, the ice layer will heat up in about 10 minutes due to heat exchange with the 0°C water and heat exchange with the evaporator, which attempts to return to room temperature. The temperature of almost the entire area rises to nearly 0℃.

Therefore, if the return temperature of the thermostat is set to 0°C or lower, the refrigerator will resume operation within a short time, but if the amount of water consumed while the refrigerator is stopped is very small, the temperature sensing temperature of the thermostat will By the time the temperature near the area reaches the lower operating temperature of the thermostat again, more ice forms on the surface of the ice layer than the amount of water consumed.

As this process is repeated, the ice layer gradually becomes thicker than the predetermined thickness as described above.

In order to avoid such a phenomenon, in the device of the present invention, the reset temperature of the thermostat is set to 0°C or higher, for example +1°C.
It is set to ℃.

However, as mentioned above, the thermostat will not return to normal unless all the ice melts.

Here, in the apparatus of the present invention, a copper rod 20 is provided as a heat transfer rod.

Since the copper rod 20 is in contact with the liquid reservoir 8a, heat transfer occurs between the copper rod 20 and the liquid reservoir 8a.

On the other hand, the temperature of the compressor inlet pipe 8 and the liquid reservoir 8a rapidly rises to room temperature when the refrigerator is stopped.

That is, during operation of the refrigerator, the liquid reservoir 8a becomes below 0°C due to evaporation of some liquid refrigerant, and frost forms, and the base of the compressor inlet pipe 8 usually reaches a temperature of 3 to 30°C due to heat from the compressor casing.
It's 5 degrees Celsius.

The liquid reservoir 8a and the inlet pipe 8 quickly reach thermal equilibrium when the refrigerator stops, and after the compressor stops, the temperature rises to room temperature in a few minutes due to the naturally circulating high-temperature gas and room temperature.

Now, one end is in contact with such a liquid reservoir, and the other end is in contact with the temperature sensing part 1.
The copper rod 20 that is in contact with 2a leads the heat of the liquid reservoir to the temperature sensing part.

While the temperature-sensing part is surrounded by ice, this heat is taken away as the melting heat of the ice, so it does not have much of an effect on the temperature-sensing part.

However, ice is gradually consumed due to heat exchange between the cooling water and the beverage in the cooling pipe 13 section, and when the ice layer thickness approaches, for example, H1, there is almost no ice in the temperature sensing part, and there is no ice near the temperature sensing part. Since the water is surrounded by the heat insulating tube 19 and its flow is prevented, there is less heat dissipation.
The temperature of the temperature sensing part or the water in the very vicinity of the temperature sensing part locally rises to 0°C or higher, and in the illustrated embodiment, for example, when the ice layer thickness is H1, the temperature of the temperature sensing part becomes 1°C.

As mentioned above, if the thermostat return temperature is set to 1°C, the refrigerator will start operating again with ice of thickness H7 remaining and will continue to operate until the ice layer thickness reaches H3. Become.

This is repeated below, and the ice layer thickness is controlled between H1 and H3.

In this way, in this invention, since heat is guided from other parts to the thermostat's temperature sensing part, ice remains in the cooling water, so even though the average temperature of the cooling water is 0°C, The temperature of the water in or around the temperature sensing portion is raised to 0° C. or higher, as shown by the temperature distribution curve indicated by the symbol T in FIG.

When this temperature reaches the upper limit operating temperature (reset temperature) ts, the thermostat is reset.

In the above embodiment, one end of the heat transfer rod (copper rod) 20 is the liquid reservoir 8a.
Although the heat transfer rod is supported in contact with the heat transfer rod, the heat transfer rod may be provided at any location, and may simply be made to protrude into the atmosphere.

As in the above embodiment, heat is not supplied while the refrigerator is operating, and the heat transfer rod is connected to the part where heat is supplied only after the refrigerator stops operating. This is reasonable in that it does not supply unnecessary heat to the temperature sensing part during the growth of the ice layer.

In the above-described embodiment, the other end of the heat transfer rod (the temperature-sensing part side) is in direct contact with the temperature-sensing part.

Such an embodiment is suitable for efficiently raising the temperature of the temperature sensing part, but if the amount of heat supplied is sufficient, the water near the temperature sensing part is locally heated without direct contact. There is no harm in heating the temperature sensitive part with this water.

Providing a partition wall such as the heat insulating tube 19 on the outside of the temperature-sensing section that allows water to communicate between the inside and outside is extremely effective in raising the temperature locally around the temperature-sensing section. It may not necessarily be provided in relation to the supply amount of

Further, even if provided, it is not necessary to use a heat insulating material if the purpose is simply to prevent the free flow of water around the temperature sensitive part.

When the heat insulating tube 19 is provided, if the mounting bracket 18 and the temperature sensing part 12a are separated by the heat insulating tube as in the illustrated embodiment, heat dissipation from the temperature sensing part to the mounting bracket or from the mounting bracket to the temperature sensor can be prevented. The effect of heat on the hot area can be eliminated and the operation of the thermostat becomes stable.

As described above, in this invention, the upper limit operating temperature of the thermostat is set to 0°C or higher, and heat is introduced from the outside to the temperature sensing part, so that no ice layer remains on the surface of the evaporator. By locally increasing the temperature sensing portion to an upper limit operating temperature of 0° C. or higher and appropriately selecting design conditions, the refrigerator can be restarted when the ice layer thickness has decreased to a predetermined value.

According to this invention, the thickness of the ice layer in the ice bank can be properly controlled using an inexpensive thermostat, and an inexpensive and reliable beverage supply device can be provided.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a beer dispenser equipped with a beverage dispensing device of the present invention, Fig. 2 is an enlarged sectional view of the main part of Fig. 1, and Fig. 3 is a sectional view taken along line III-IV in Fig. 2. , 4th
The figure is an explanatory diagram showing the temperature distribution within the ice layer. 2... Electric compressor, 4... Condenser, 7... Evaporator, 8a... Liquid reservoir, 9
...Aquarium, 10...Cooling water, 11...
... Ice layer, 12 ... Thermostat, 12
a...Temperature sensing part, 13...Beverage cooling pipe.

Claims (1)

[Claims] 1. In water stored in a water tank, an evaporator of a refrigerator that cools the water and a beverage cooling pipe that cools the beverage by heat exchange with the water through which the beverage passes are juxtaposed. In a beverage cooling device in which an ice layer is formed on the surface of the evaporator, a thermostat is provided with a temperature sensing part located near the surface of the evaporator, and the lower limit temperature at which the thermostat operates is set to 0°C. In the following, the upper limit temperature is set to 0°C or higher, and a means is provided to conduct heat to the temperature sensing part, and when the refrigerator is operated and the ice layer grows to an appropriate thickness, the temperature sensing part is covered with ice. In rare cases, when the temperature of the temperature sensing part reaches the lower limit temperature, the operation of the refrigerator is stopped, and when the operation of the refrigerator is stopped and the ice melts and the ice layer thickness decreases, the heat guided by the means A beverage cooling device characterized in that the operation of the refrigerator is restarted when the temperature of the temperature sensing section locally reaches the upper limit operating temperature even though ice remains on the surface of the evaporator. 2. Patent The beverage cooling device according to claim 1, wherein the means for guiding heat to the temperature sensing part is a heat conductive rod-shaped body having one end close to the temperature sensing part and the other end protruding above the water surface. 3 Patent The beverage cooling device according to claim 2, wherein the other end of the rod-like body is thermally connected to a portion that reaches a temperature of 0° C. or higher only when the refrigerator stops operating. 5. The apparatus according to claim 1, wherein the part to which the other end of the rod-like body is connected is a liquid reservoir for gas-liquid separation provided at the outlet of the evaporator. 5. The apparatus according to claim 1. , a beverage cooling device having a partition wall provided outside the temperature-sensing section through which water inside and outside communicates with each other. 6. In the device according to claim 5, the partition wall is fitted into the temperature-sensing section with one end protruding above the water surface. A beverage cooling device that is an insulated tube with open ends.