JPH0621753B2 - How to prevent the generation of incomplete ice in an ice maker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a method for preventing the generation of incomplete ice in an ice making machine, and more particularly, to detect a change predicting the occurrence of incomplete ice in a certain part of the ice making machine, The present invention relates to a method for preventing the generation of incomplete ice in an ice making machine, which operates a prevention means for preventing the generation of incomplete ice in response to this detection signal.

b. Conventional Technology A conventional water circulation type ice making machine, as shown in FIG.
Ice making water tank 1, deicing water tank 2, circulation pumps 3, 4,
It comprises a refrigeration circuit including water sprinklers 5 and 6, and an evaporator 15. The refrigeration circuit includes a compressor 11, a condenser 12, a solenoid valve for refrigerant 18, a heat exchanger, as already known. 13, an expansion valve 14, the evaporator 15, an accumulator 16 and a hot gas solenoid valve 17, and a deicing circuit.

The deicing cycle is started when the water level in the ice making water tank 1 is lowered to a certain level. When the circulation pump 4 is started, the deicing water enters the sprinkling pipe 6 from the deicing water tank 2 through the pipe line, is sprayed from the sprinkling hole to the back surface of the ice making plate composed of the evaporator 15, and flows down to a water collecting trough or the like. Enter the ice-making water tank 1 via the route. At the same time, the hot gas solenoid valve 17 of the deicing circuit is opened to supply the hot gas to the evaporator 15 to separate the ice adhering to the surface of the ice making plate. Then, the ice making water tank 1 is filled with deicing water.

Next, the ice making cycle is disclosed after a certain time has elapsed from the start of the deicing cycle or when the intake gas temperature is detected and the set condition is satisfied. When the circulation pump 3 is activated, the ice making water enters the water spray pipe 5 from the ice making water tank 1 through the pipe line, is sprayed from the water spray holes to the surface of the ice making plate consisting of the evaporator 15, and flows down, and the ice making plate makes ice. The part that does not come into the ice-making water tank 1 is circulated through a channel such as a water collecting gutter. At the same time, in the refrigeration circuit, the hot gas solenoid valve 17 and the refrigerant solenoid valve 18 of the deicing circuit are closed, and the refrigerant is transferred from the compressor 11 to the condenser 12 to the heat exchanger 1.
3. After entering the evaporator 15 through the expansion valve 14, the ice making plate is cooled and circulated through the heat exchanger, the accumulator 16 and the compressor 11.

In this way, ice is created and stored by repeating the deicing cycle and the ice making cycle.

By the way, in the case of an ice making machine, in particular, such a water circulation type ice making machine, an ice crystal is instantaneously generated from the supercooled water, and the flow of the ice making water on the surface of the pipe, the water collecting gutter, and the ice making plate. As an incomplete ice (hereinafter referred to as "cotton ice"), various preventive measures are considered. For example, in Japanese Examined Patent Publication (Kokoku) No. 58-15706, a temperature detector 8 capable of detecting the temperature of ice making water is provided in a portion of an ice making machine or in the vicinity of a water collecting gutter, and a change for predicting the occurrence of incomplete ice, for example, temperature gradually It is disclosed that the temperature of the water circulating in the circulation path is reduced to a predetermined amount or less for a predetermined time by detecting the case where the temperature falls to + 1 ° C to 0 ° C. See Fig. 4.) c. Problems to be solved by the invention The conventional method for preventing cotton ice in an ice-making machine reduces the amount of ice-making water in the circulation path during the ice-making cycle. Had some drawbacks.

(1) The ice making water returned from the circulation path overflows from the ice making water tank and flows into the de-icing water tank. Therefore, extra ice making water (about 20% of the ice making amount) returned at each ice making cycle is added. Not only is the energy wasted due to cooling, but the water temperature in the deicing water tank is lowered, the efficiency of the deicing cycle is reduced, and the ice making capacity of the ice making machine is greatly reduced.

(2) Rapidly reducing the load (ice making water) during operation of the refrigeration circuit causes a liquid back phenomenon of the refrigerant, which causes failure of the circuit, especially the compressor.

The present invention has been made in order to eliminate such drawbacks, by controlling the refrigerant in the refrigeration circuit without affecting the ice-making water such as the circulation path, the generation of cotton ice in the ice-making machine. The aim is to provide a method that can be prevented.

d. Means for Solving the Problems In order to achieve the above object, the present invention detects a change that predicts the occurrence of incomplete ice in a certain part of an ice making machine, and responds to this detection signal to detect the incomplete ice. In the method for preventing the generation of incomplete ice in an ice making machine, which operates a prevention means for preventing the occurrence of the above, as the prevention means, the low pressure of the refrigeration circuit or the temperature of the evaporator is a constant value capable of avoiding the generation of cotton ice. The solenoid valve for expansion or the expansion valve for the refrigerant in the refrigeration circuit in operation is closed until the temperature drops to 0.

e. Detecting a change that predicts the occurrence of incomplete ice in a part of the ice making machine, and responding to this detection signal, the solenoid valve for expansion or the expansion valve for the refrigerant in the refrigeration circuit under operation is closed, so the evaporator In the above, the temperature is rapidly reduced due to rapid cooling, and ice nuclei necessary for normal ice growth are formed on the surface of the ice making plate, so that the production of cotton ice can be prevented particularly in the ice making plate.

The time when the refrigerant solenoid valve or expansion valve is closed is
Depending on the conditions such as the outside air temperature, the difference from the freezing temperature of ice-making water (around 0 ° C) is as quick as possible, and when making a large temperature difference, there is no cotton ice and the temperature of the evaporator is minus a few degrees. It is effective if it drops sharply. Further, the low-pressure pressure of the refrigeration circuit is in direct proportion to the temperature of the evaporator, and the constant pressure value can be easily converted from the constant temperature value.

f. Example Hereinafter, the case where the example of the present invention is applied to the water circulation type ice making machine shown in FIG. 1 will be described.

For ice machines, a pressure switch 1 is installed in the low pressure section of the refrigeration circuit.
9. The same as the conventional one except that the temperature detector 20 that can detect the saturation temperature of the refrigerant is attached to the inlet of the evaporator 15, and the same parts are denoted by the same reference numerals and the description thereof is omitted.

The deicing cycle and the ice making cycle are the same as the operation of the conventional water circulation type ice making machine, but during the ice making cycle, the temperature detector 8 that detects the temperature of the ice making water predicts the occurrence of incomplete ice. Change, for example, the temperature gradually decreases to 0
When the temperature between 1 ° C. is detected, the electromagnetic valve 18 for the refrigerant is connected to the temperature detector 2 at the inlet of the evaporator 15 based on the detection signal.
Close until 0 drops sharply to minus a few degrees C. Thus, the supply of the refrigerant is temporarily stopped and the gas pressure of the refrigerant sharply decreases, whereby the temperature of the ice making plate cooled by the evaporator 15 is drastically decreased, and the temperature difference between the ice making water and the ice making plate is decreased. Becomes larger, and ice nuclei necessary for normal ice growth occur on the surface of the ice making plate. Therefore, it was confirmed that cotton ice did not occur at least near the ice making plate where cotton ice was most likely to occur.

It has been actually measured that the gas pressure in the low pressure portion is proportional to the temperature detected by the temperature detector near the inlet of the evaporator 15, and the pressure switch is performed at a low pressure where the temperature of the evaporator 15 becomes minus several degrees C. Even when 19 was set, the same operation and effect as using the temperature detector 20 were obtained.

Further, even if the expansion valve 14 is used as a pulse motor drive instead of the electromagnetic valve 18 for refrigerant, the same operation and effect can be obtained.

Furthermore, in order to detect a change that predicts the occurrence of incomplete ice, as disclosed in Japanese Patent Publication No. 58-15706,
It goes without saying that a low pressure detection or a temperature detector provided near the evaporator may be used. Even in a water storage type ice making machine, the method for preventing the generation of incomplete ice by controlling the refrigerant according to the present invention has the effect of preventing cotton ice.

g. Effect of the Invention According to the present invention, as a countermeasure against cotton ice, the low-pressure pressure of the refrigeration circuit or the temperature of the evaporator is reduced to a constant value at which the generation of cotton ice can be avoided until the refrigeration circuit is in operation. Since it only closes the solenoid valve or expansion valve for the refrigerant in
There are no drawbacks due to the ice making water returned from the circulation path that conventional cotton ice prevention measures have, and there is no fear of liquid back phenomenon of the refrigerant.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a water circulation type ice making machine for applying the method of the present invention, FIG. 2 is a time table when the method of the present invention is applied to the ice making machine of FIG. 1, and FIG. FIG. 4 is a schematic diagram of the water circulation type ice making machine, and FIG. 4 is a time table when the conventional method is applied to the ice making machine of FIG. 1 ... Ice water tank, 2 ... De-icing water tank, 3, 4 ...
Circulation pump, 5, 6 ... Sprinkling pipe, 8,20 ... Temperature detector, 11 ... Compressor, 12 ... Condenser, 13 ... Heat exchanger, 14 ... Expansion valve, 15 ... Evaporator, 17 ... solenoid valve for hot gas, 18 ... solenoid valve for refrigerant.

Claims (1)

[Claims] 1. An incomplete ice in an ice making machine, which detects a change predicting the occurrence of incomplete ice in a certain part of the ice making machine, and operates a preventive means for preventing the generation of incomplete ice in response to the detection signal. In the method for preventing the occurrence of the above, as the above-mentioned preventing means, the low-pressure pressure of the refrigeration circuit or the temperature of the evaporator is lowered to a constant value capable of avoiding the generation of cotton ice, or the solenoid valve for refrigerant in the operating refrigeration circuit or A method for preventing the generation of incomplete ice in an ice making machine, characterized by closing an expansion valve.