JPS5815706B2 - Incomplete ice generation prevention device in water circulation type ice making mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that prevents the phenomenon of incomplete water (hereinafter referred to as pure water or muddy water) occurring just before freezing, which is unique to water circulation type ice making mechanisms.

The water circulation type ice making mechanism is an ice making mechanism that flows water over the surface of the ice making plate and repeatedly generates pure ice without any impurities on the plate surface. Depending on the shape of the ice making plate, it can be , vertical pipe type, sloped top flow type, sloped bottom flow type, concave flow type, fountain type, etc., but all of them require that the freezing point of the flowing water be 0 in order to freeze it.
It is characterized by being lower than ℃, and the common feature is that pure water or muddy water occurs just before freezing begins.

The manner in which it occurs varies depending on the flow velocity and plate surface temperature, but among the above, in the case of a fountain type where the flow velocity is high and the plate surface temperature is low, it occurs in a cotton-like form, instantaneously, and in a collection where unfrozen water falls. It is characterized by occurring all at once in the gutter or water tank, but in the case of a vertical plate system where the flow velocity is slow and the plate surface temperature is high, it occurs gradually and locally on the plate surface in the form of mud. .

However, in either case, once enough pure water or muddy water is generated, it gradually transitions to complete ice.
In the end, a complete block of ice can be obtained, so there will be no fatal accident, but the circulation will be temporarily stopped and the amount of ice produced will be reduced accordingly, resulting in blockage of pipes and flooding. Such problems cannot be avoided.

A method and device for effectively eliminating generated pure water or muddy water is disclosed in Patent Application No. 126100 filed in 1973 by the same applicant as the present application, “Method and device for eliminating muddy and flocculent ice in a water circulation type ice maker”. '' (Japanese Patent Laid-Open No. 55-53668), but this is an attempt to eliminate pure water or muddy water after it has been generated, so it is not a fundamental solution.

Therefore, an object of the present invention is to provide a device for preventing the generation of incomplete rice in a water circulation type ice making mechanism, which prevents the generation of pure water or muddy water itself, and fundamentally solves the above-mentioned problems caused by the generation. It is.

In order to achieve the above object, the inventor of the present application has elucidated the mechanism of generation of pure water or muddy water, and as a result, the inventor of the present application has discovered that the circulating water flow is supplied at the point when incomplete rice is generated on the ice making plate surface, or just before that point. By temporarily interrupting and reducing the water flow for a predetermined period of time, the plate surface is supercooled or forced to form an initial ice film, and then the circulating water flow is restored to achieve the desired effect. I learned about scales.

The predetermined period of time means that the ice-making plate surface of the ice-making mechanism becomes supercooled due to the interruption of flowing water, or forms an initial ice film due to a decrease in the flowing water load, and even when the next cycle of circulation resumes. This is the minimum amount of time necessary for the rice to be cooled to a level that does not result in incomplete rice.

In order to better understand this invention, we will first give a comparative description of the two most different examples of the mechanisms for generating pure water or muddy water, namely the case of a vertical plate type and the case of a fountain type. As shown in the graph in Figure 5, soon after turning on the refrigeration circuit and circulation pump to start ice-making operation, and before time C when ice film is expected to form on the plate surface, the plate surface Small mud-like lumps form and stick to ice cubes6), and their number gradually increases, and the oldest ones fall off under the weight and flow down the water collection gutter below the ice-making plate.

At this time, if you pick it up and observe it, you will see that it is a collection of small scale-like pieces.

The number of ice formations on the board surface increases over time, and the amount of ice generated on the board surface exceeds the amount of falling objects, to the point where the board surface is covered, but by this time, a normal film of ice has already formed on the board surface. (C), the remaining nodules are also wrapped up in the thin ice film that is firmly attached to it, which continues to grow and eventually becomes an ice plate, but the change in the nodules that are wrapped inside is somewhat interesting. be.

In other words, the opaque and soft muddy water, which looks like sherbet at first, rises up from the surface of the board and barely sticks to it, but the surface it adheres to gradually becomes more solid, and before you know it, it becomes transparent and covers the surrounding ice sheets. It becomes indistinguishable, and completely assimilates, leaving no trace of the original.Also, the mud particles that fell off and fell down the water collection gutter could temporarily clog the water collection gutter or cause it to overflow. Although it may cause an accident, it will eventually melt and disappear completely, and will not destroy the ice-making function itself.

On the other hand, in the case of the fountain type, the change occurs in the ice-making water tank where water is sprayed from below and flows down into the numerous ice-making chambers that open downward.

In other words, water is falling from above like a shower on the surface of the water stored in the tank, but after a while of ice-making operation, when it seems that a thin film of ice is about to form on the inner wall of the ice-making chamber, The water temperature gradually decreases, and the moment it reaches a delicate temperature (approximately -0.5 to -0.7 degrees Celsius in fountain-type experiments), the entire stored water suddenly transforms into a large cotton-like mass. do.

Therefore, the pipe port from the tank to the circulation pump is instantly blocked, the circulation pump idles, and the fountain and accompanying shower of water stop.

If this continues for a few minutes, the pure water nodule will begin to melt little by little from its outer periphery (the speed of this will vary depending on the season due to the influence of external temperature).

This melted water is sucked into the idling circulation pump, causing the fountain to revive slightly, and when the falling water revives slightly, the inside of the tank is again slightly disturbed.

This slight disturbance helps the melting of the water, the amount of melting increases slightly, and thus the melting is promoted in a chain reaction, finally circulating! will return to normal, and the remaining pure water mass will disappear at once.

During this period, the time during which the circulating flow is stopped is approximately 3 minutes in summer, and about twice that time in winter.

Furthermore, considering the actual damage caused by the occurrence of incomplete rice mentioned above, in the case of the vertical flat plate type, there are visible problems such as clogging of the water collection gutter and causing accidents such as hot water, but if the rice falls off, The amount of muddy water that is remelted will cause a slight delay in the freezing effect, resulting in a loss of ice-making capacity.

On the other hand, with the fountain type, there are no visible accidents (although this countermeasure has not been taken to this day because there have been no visible accidents), but the ice making cycle is temporarily interrupted. This results in a reduction in the daily amount of ice making, and for example, in an ice making mechanism with an ice making cycle of 30 minutes, this 3 minute stoppage leads to a loss on one side.

For this reason, it is necessary to shorten this interruption time.

FIG. 1 shows only one example of a vertical flat plate type water circulation type ice making mechanism to which the present invention can be applied. In the figure, the ice making mechanism is generally indicated by the reference numeral 1. A water collecting gutter 3 which is arranged at a slight inclination below this square ice-making plate 2 and opens upward, and an ice-making water tank 4 arranged diagonally below the water collecting gutter 3 are provided.

An evaporation pipe 5 connected to the refrigeration system is arranged in a meandering manner on one side of the ice-making plate 2, and a water sprinkling pipe 6 is arranged parallel to this near the horizontally extending top of the ice-making plate 2. The drilled water sprinkling holes 7 are directed toward the ice-making surface of the ice-making plate 2.

An ice-making water supply pipe 8 is led out from the bottom of the ice-making water tank 4 and connected to the water sprinkler pipe 6 via a circulation pump 9 and a water pressure control valve 10.

Therefore, when the valve 10 is opened and the circulation pump 9 is driven, the ice-making water in the ice-making water tank 4 is forced into the supply pipe 8 in the direction of the arrow, and directed toward the ice-making plate 2 through the water sprinkling holes 7 of the water sprinkling pipe 6. water is evenly distributed.

A dish-shaped support member 11 is removably fitted into the ice-making water tray 4, and the structure is such that a portion above the support member 11 and a portion below the support member 11 can communicate only through the filter 12. .

An overflow pipe 13 extending vertically is also provided on the support member 11, and the overflow pipe 13 is led out from the bottom of the ice-making water tank 4 in a watertight manner and faces the reserve tank 14.

The reserve tank 14 is used to store water used to peel (de-ice) the ice plate from the ice-making plate 2 when ice making is completed. It is connected via a water pressure regulating valve 17 to a deicing water pipe (not shown) disposed close to the ice making plate 2.

Note that reference numeral 18 indicates a float type main valve for supplying deicing water or external tap water to the reserve tank 14.

In this ice-making mechanism 1, by starting the operation of the refrigeration system to cool the ice-making plate 2, and at the same time driving the circulation pump 9, the ice-making water in the ice-making water tank 4 is pumped through the supply pipe 8, and the ice-making water is pumped through the supply pipe 8, and the ice-making water is pumped through the supply pipe 8. It reaches the water sprinkling pipe 6 through the valve 10 which is adjusted at the same time, and is sprayed onto the ice making surface of the ice making plate 2 through the water sprinkling hole 7.

The sprayed ice-making water flows uniformly down the ice-making plate surface, and unfrozen water flows down from the ice-making plate 2 and is collected in the water collection gutter 3, flows through the slightly inclined water collection gutter 3, and passes through the filter 12. After being drained, it returns to the ice making water tank 4.

°The returned ice-making water passes through the supply pipe 8 again and is circulated and supplied to the ice-making plate surface, so that the unfrozen water is cooled to below the freezing temperature and is in a state where it can be frozen instantaneously. (Since it is flowing, it has not yet solidified.)

Unfortunately, since the ice-making plate surface is the part most likely to freeze, pure water and muddy water are formed on the ice-making plate surface in the manner described above.

According to this invention, in order to prevent the generation of such pure water or muddy water, the point in time when pure water or muddy water is generated on the ice-making plate surface is detected in advance, and immediately before that point, the ice-making water from the circulation pump 9 is pumped. supply is temporarily interrupted for a predetermined period of time, but not yet reduced.

As a result, the surface of the ice-making plate is supercooled, or the formation of an initial ice film is forced, and even if the supply of ice-making water is restarted after the above-mentioned predetermined period, pure water is no longer generated.

Therefore, the above-mentioned predetermined period means that the ice-making plate surface is supercooled due to the interruption of the ice-making water, or that an initial ice film is formed due to a decrease in the ice-making water load, and then the ice-making water becomes normal. This is the minimum time necessary until the water is cooled to a point where pure water will not be generated even if the water is supplied.

The timing of pure water generation differs depending on various conditions.

The conditions under which this phenomenon is likely to occur are as follows, and the above-mentioned predetermined period can be appropriately determined in consideration of these conditions.

(1) If the ice making plate is made of aluminum, this will occur more often than if it is made of copper.

(2) There is often an imbalance between the efficiency of the evaporator (ice-making plate) and the compression function, and the compression function is lower than the other.

(3) When the amount of circulating water is too large, or when the flow velocity is still fast.

(4) When the air and water temperatures are high, such as during the summer.

(5) This tendency is stronger in the 50H2 area than in the 60H2 area (rotational speed of compressor and circulation pump).

(6) The first time a machine resumes operation after being out of service for a long time.

(7) Insufficient amount of cooling water in the condenser or insufficient air volume for air-cooled condensers.

(8) In a vertical plate ice making mechanism that circulates both ice making water and deicing water, if the ice making water reaches a high temperature due to an operational error, such as immediately after deicing.

FIG. 6 is a graph showing the mechanism for preventing the generation of pure water or muddy water according to the present invention in the case where the circulation pump of the vertical flat plate ice making mechanism is turned ON and OFF, similar to the case in FIG. Time B when expected to occur
The circulation pump 9 is stopped at A about 15 seconds before (Fig. 5), and B
At the point in time, the circulation pump 9 is restarted.

Time A when the circulation pump stops is not necessarily time B when muddy water is expected to occur.
The circulating pump may be restarted approximately 15 seconds after the time point B, rather than approximately 15 seconds before the time point B, at a time point that is almost the same as or just before the time point B.

As can be seen from FIG. 6, according to the present invention, generation of muddy water is completely prevented even when pure water is not present.

Furthermore, when comparing the graphs in Figures 5 and 6 by overlapping them as shown in Figure 1, it can be seen that the amount of ice produced in the case of this invention (graph "C") is more or less larger. .

Note that the graphs ``I'', ``口'', and ``HA'' all indicate general trends, and it has not been actually measured so far whether the graph ``NO・'' is a straight line or a curve.

FIG. 2 shows an embodiment of the above-mentioned incomplete water generation prevention device. In this embodiment, a variable factor (in this example, time from the start of operation) in the ice making mechanism that predicts the generation of incomplete water is used. As a means for detecting this, one timer 19 is incorporated into the electric circuit of the pump motor 20 that drives the circulation pump 9, and the above-mentioned pump control is performed.
The timing of generation of incomplete water is experimentally determined in advance, and the timer 19 is activated at the same time as the start of operation, and when the set time corresponding to the timing of generation of incomplete water is reached, the pump motor 20 is turned off.
Make it FF.

Therefore, the circulation pump 9 is a means for reducing the amount of water circulated in the supply pipe 8 to a predetermined amount or less as necessary in response to the detection by the timer 19, which is a detection means.

Further, a delay relay 21 is operated in conjunction with the timer 19, and after the pump motor 20 is turned off, the pump motor 20 is turned on again after the predetermined time has elapsed.

The setting times of the timer 19 and the delay relay 21 for canceling the reduction in water circulation amount can be set to adapt to the conditions described above. For example, the timer 19 is set to several minutes, and the delay relay 2
1 can be variable within the range of 0 to 60 seconds.

In addition, as an application example of this invention, only the refrigeration circuit is started at the same time as the ice-making operation starts, the circulating water remains stopped, and the circulating water is restarted after a certain period of time, without detecting the variable factors in the ice-making mechanism. Although it is possible to consider a method to achieve a similar effect by doing this, experiments have revealed the following advantages and disadvantages, and the disadvantages are greater, so this method could not be put to practical use.

Strong Points (1) No equipment or instruments are required to detect variable factors.

Disadvantages (1) No load (or slight load) due to interruption in the middle of ice making operation
Unlike cooling, the ice-making plate is cooled with no load (or slight load) from the initial stage or from room temperature immediately after deicing, so it takes a longer time to reach supercooling, and the ice-making plate does not expand or contract. The strain was so large that there was concern about fatigue damage, especially at the refrigerant inlet and outlet sections.

(2) The time required for supercooling is about 3 to 5 minutes compared to about 15 degrees in the case of the present invention, which cannot be ignored in terms of daily ice production.

(3) Although this downtime was useful in terms of protection against overcurrent during startup of the compressor, it was still unsatisfactory in terms of preventing the generation of incomplete water.

(4) During this downtime, naturally the low pressure side of the high/low pressure switch in the refrigerant circuit was activated and the operation was stopped.

(5) This rest time varies greatly depending on the external temperature,
Like the timer detection type mentioned above, it was necessary to adjust according to the temperature.

Moreover, this adjustment required delicate and troublesome operations.

(6) Since the ice-making plate was in a dry state, scale adhesion to the plate surface was increased.

FIG. 3 shows another embodiment of a device for preventing the generation of incomplete water. This device detects a predetermined temperature of circulating water as a variable factor in the ice making mechanism with a thermostat 24, stops the pump motor 20, and at the same time The delay relay 21 is activated and the pump motor 20 is turned on after a predetermined time.

The predetermined temperature is the temperature at which a thin ice film, which is the base of pure water or muddy water, is thought to be formed, that is, the temperature at which the temperature of the circulating water gradually decreases (approximately -0 in experiments with fountain type). ，
5 to -0.7°C), and in this example, the thermostat 24 is set to 1.5°C.

However, the set temperature varies within a range of ±0.5°C or more depending on the installation location of the thermostat temperature sensor.

Further, the predetermined time is the same as that described for the embodiment of FIG.

It is preferable to attach the thermosensor tube somewhere in the area indicated by the symbols A-E in FIG.

Here, A: Part inside the water pipe B: Upstream part inside the water collection gutter C: Downstream end inside the water collection gutter D: Near the filter frame E: About 1/3 part from the bottom of the ice making water tank Since parts B and C in the water gutter are close to the ice plate surface,
There is little error in the detected temperature, and since it is outside the ice plate falling path, it does not pose any obstruction, and is also conveniently located for maintenance and inspection.

Additionally, this method is reliable, easy to implement, and inexpensive.

This embodiment also has a pump motor 20 similar to the one in FIG.
ON10 FF Instead of controlling the thermostat)b
It can be modified to control the amount of ice-making water supplied to the water sprinkler pipe by any suitable means using a combination of a delay relay and a delay relay.

・Furthermore, according to the present invention, the point in time when fine ice or muddy water is generated on the ice making plate surface is detected in advance, and at or just before that point,
Since the desired effect can be obtained even if the supply of ice-making water from the circulation pump 9 is temporarily reduced to a predetermined amount or less for a predetermined period of time, it is not necessarily necessary to turn off the pump motor 20 by the timer 19.

Instead, as shown in dashed lines in FIG. 1, a high-resistance bypass 23 with a solenoid valve 22 is provided for valve 10, which closes valve 10 when timer 19 reaches a set time and closes valve 22. The opening flow rate may be suddenly reduced.

Alternatively, a solenoid valve may be provided in the supply pipe 8 itself to control the valve between a fully open position and a half open position.

When the delay relay 21 reaches the set time, the valve 10 opens and the valve 22 closes, returning to the original state.

In short, it is sufficient if there is a means to reduce the supply of ice-making water to a predetermined amount or less, and it may be reduced to zero.

FIG. 8 shows the circulation pump 9 using the embodiment shown in FIG.
Graph a with a solid line and graph b with a dashed-dotted line show the operating cycles when the OFF control is performed. The relationship between time and temperature is indicated by A, which is the point at which the circulation pump is stopped, and B, which is the predicted point at which muddy water is generated, and which is determined by the point at which the circulation pump is restarted.

FIG. 10 shows graphs a' and b' obtained by actually measuring temperature changes in the vicinity of the expected muddy water generation point with thermostats installed at the above-mentioned positions a and b.

As you can see from this graph, the temperature of the circulating water changes rapidly near the point where muddy water is expected to occur, so by determining this in advance and setting the thermostat to that temperature or a slightly higher temperature, the pump can be easily adjusted. Can control motors.

In the embodiment shown in FIG. 3, the temperature of the circulating water is detected by a thermostat, but the above-described control can also be performed by detecting the temperature of the refrigerant as a state quantity.

The configuration in this case is exactly the same as the embodiment shown in Fig. 3, except that the temperature sensing cylinder is installed at one place on the low pressure side of the refrigerant circuit, and of course the set reference temperature is the high temperature point, and the thermostat used is The characteristics must also be selected accordingly.

The mounting locations are almost the same on the low pressure side, but the locations indicated by symbols F, G, and H in Figure 1 are advantageous, and in particular, the location F, approximately in the center of the evaporation tube on the back of the ice-making plate, is safe in all cases. be.

Furthermore, this method is advantageous over the method of FIG. 3 in the case of a fountain ice making mechanism for the following reasons.

In other words, in the case of a fountain type, the flowing water part is completely sealed, so there is no suitable place to attach a thermosensor, and even if it were installed, the flowing water part is all in one place. Since it tilts to open and close, it puts strain on the wiring and lacks durability.

On the other hand, in this method of detecting refrigerant temperature, the temperature sensing tube is fixed to the evaporation tube, so it is immovable, and the wiring can also be covered and insulated.

According to the actual measurement results, the refrigerant temperature in the low-pressure piping changes linearly in almost proportion to the water temperature until the occurrence of incomplete water, so it is thought that the reliability is almost the same as that of water temperature detection. .

Furthermore, as shown in FIG. 4, a capillary tube 26 is led out from a part of the low-pressure side piping 25 of the refrigerant circuit and connected to a pressure switch, and changes in the refrigerant pressure are detected and the pump motor is activated at the time before incomplete Himi. It is also possible to turn 20 off.

When a reciprocating compressor is used in a refrigeration circuit, pressure pulsations occur, but if a pressure switch is provided on the low pressure side, the pulsations will hardly affect the pressure.

The advantage of this method is that it can be installed in a convenient location near the compressor, since the detection part does not make much difference anywhere as long as it is a low-voltage circuit, and there is no need to install precision parts in areas with poor conditions near the ice-making plate. Since there are no holes, it is advantageous for maintenance, inspection, service, etc., and it is easy to manufacture.

As is clear from the above description, according to the present invention, the generation of fine ice and muddy water itself is prevented, so there is no need for conventional measures such as heating or heat exchange to eliminate the occurrence of muddy water. Does not affect cooling efficiency in any way.

Additionally, since the parts used are not moving parts, there are no new causes of failure, and all parts are inexpensive.

Since accidents caused by clogging of the circulation waterway are eliminated, there is no need to take any measures to prevent accidents.

In addition, with the fountain type and vertical pipe type, there is no loss of ice production due to temporary stoppage of circulating flow, and with the vertical plate type, sloped bottom flow type, and concave flow type, the water flow on the plate surface is obstructed by the upheaval of incomplete ice blocks. Therefore, there is no risk of electrical leakage caused by side currents or splashes that wet nearby control parts.

Particularly, in a pure water production apparatus using an inclined downward flow type ice making mechanism, the problem of muddy water falling into a water storage tank is eliminated.

Although this invention has mainly been described with respect to a vertical flat plate ice making mechanism, it is of course applicable to all types of water circulation type ice making mechanisms, and such ice making mechanisms can naturally be used in ice making machines, pure water production equipment, etc. can.

However, the detection position when incomplete water is generated is not limited to any location in the circulating water basin in the case of water temperature detection, as in the above example, and similarly, the detection position at the time of generation of incomplete water is not limited to any location in the refrigerant circuit in the case of refrigerant temperature detection. Furthermore, in the case of refrigerant pressure detection, any position may be used as long as it is on the low pressure side of the refrigerant circuit.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an ice making mechanism that implements a device for preventing the generation of incomplete water according to the present invention, and FIGS. 2 and 3 are schematic diagrams of different embodiments of the device for preventing the generation of incomplete water according to the present invention. Figure 4 is a cross-sectional view of a pressure detection capillary tube in yet another embodiment of the present invention, Figure 5 is a diagram illustrating the mechanism of incomplete water generation in a conventional ice making mechanism, and Figure 6 is a diagram illustrating the mechanism of incomplete water generation according to the present invention. 7 is a composite diagram of the graphs of FIGS. 5 and 6, and FIG. 8 is a diagram illustrating the ice production process in an ice making mechanism equipped with an ice generation prevention device. FIG. Fig. 9 is a side view and end view showing the circulating water temperature detection position in Fig. 8, and Fig. 1 σ is an ice making mechanism that does not implement this invention. FIG. 2 is a diagram showing changes in circulating water temperature near the expected muddy water generation point in FIG. In the figure, 1 is an ice-making mechanism, 2 is an ice-making unit (ice-making plate), 9 is a circulation pump which is a reduction means, 19 is a timer which is a detection means, 21 is a delay relay which is a release means, and 24 is a thermostat which is a detection means. It is.

Claims (1)

[Scope of Claims] 1. In order to prevent the occurrence of incomplete water in an ice making mechanism that circulates water to an ice making section in a circulation path to make ice, a variable factor in the ice making mechanism that predicts the occurrence of incomplete water is provided. means for detecting a predetermined value of , and means for reducing the circulating amount of water in the circulation path to a predetermined amount or less in response to the detection by the detecting means; A device for preventing generation of incomplete water in a water circulation ice making mechanism, comprising a releasing means related to the reducing means. 2. The variable factor in the ice making mechanism is the time from the start of operation of the ice making mechanism, and the detecting means is a timer; A device for preventing generation of incomplete water in a water circulating ice making mechanism according to claim 1, wherein the release means is a delay relay. 3. The variable factor in the ice making mechanism is the temperature of the circulating water, and the detection means is a thermostat. , the release means is a delay relay.Claim 1: JFh!ii" Ring-type ice making mechanism 2. A device for preventing generation of incomplete water in a water circulation type ice making mechanism according to claim 1, wherein the releasing means is a delay relay. 5. A device for preventing generation of incomplete water in a water circulation type ice making mechanism according to claim 2 or 3, wherein the reducing means is a circulation pump provided in the circulation path.