JPH09273841A - Method for making ice and equipment therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for making ice and equipment therefor wherein water is sprinkled and made to flow down on the surface of a freezing plate and an ice layer is formed thereon and made to grow into thick plate-shaped ice. SOLUTION: A compressor is operated so that a pressure of suction of a refrigerant be changed gradually to 4.0-1.0kg/cm<2> and that a cooling capacity per freezing plate be 1000kcal/hr±10%, and the bore of a nozzle hole of a sprinkling pipe is set to be 3.5±2.0mm and a nozzle pitch to be 17.5±3.0mm. At the time when ice making is completed, sprinkling of water is stopped, while the refrigerant in the freezing plate is sucked so that ice be removed, and plate-shaped ice thus removed is transferred by an arm being elevatable and swingable. According to this constitution, the thickness of the ice is made about 50mm, it is unnecessary to provide a piping for hot water or hot gas for removal of the ice and, besides, the noise generated on the occasion of the removal of the ice is suppressed remarkably.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice making method and an apparatus therefor, and in particular, a raw material water is circulated to an ice-making plate to form and grow an ice layer on the ice-making plate to form a plate-shaped product. The present invention relates to an ice making method for defrosting ice pieces and optionally crushing to crush ice, and an ice making device for carrying out the method, and particularly to a plate-like ice or a large crushed ice having a larger thickness than conventional ones. The present invention relates to an ice making method and an ice making device.

[0002]

2. Description of the Related Art A cooling medium is introduced to cool an ice plate, and raw material water is circulated and flowed down from the top of the ice plate to form and grow an ice layer on the ice plate. Various methods have been proposed for deicing the resulting plate-shaped ice pieces and optionally crushing them into crushed ice (see, for example, JP-A-2-118375,
(See Japanese Patent Publication No. 5-23350 and Japanese Patent Laid-Open No. 5-296626).
The applicant company also developed the above-mentioned water spraying / flowing-down type automatic ice-making machine, and sells it as “Istar” (trademark) MD series.

[0003]

[Problems to be Solved by the Invention or Objects of the Invention]
It takes 27 minutes and the de-icing time is 3 minutes.Therefore, one ice making cycle is as short as 30 minutes, and the resulting crushed ice has excellent transparency and smoothness and good productivity, but its thickness is about 15 mm. Even if the operation is adjusted to increase the thickness, the limit is about 25 mm, and there is a problem in that productivity decreases as the thickness increases. With regard to the demand for crushed ice, if the thickness is about 15 mm as described above, it is generally acceptable, but when it is put in an ice box for fishing and used for cooling, for example, small blocks are larger than large blocks. However, there is a slight problem in that it lacks versatility.

Therefore, a first object of the present invention is to provide ice having a thickness of up to about 50 mm, excellent versatility and excellent transparency. A second object of the present invention is that the deicing method of the plate-shaped ice pieces formed on the surface of the ice plate has hitherto been by spraying hot water on the opposite surface of the ice plate or, if necessary, supplementing hot gas. It was a system that warms the ice plate by supplying it and melts part of the ice on the ice plate, but in order to shorten the time required for de-icing, in addition to the pipe for hot water supply, the pipe for hot gas However, there is a problem in that it is necessary to improve the de-icing method because it is disadvantageous in terms of thermal efficiency because the de-icing method needs to heat the freezing plate that should be cooled. . A third object of the present invention is that a conventionally formed plate-like ice piece falls on a slanting plate and is guided to a crusher by the slanting plate, and a considerable impact sound is generated at the time of the fall. However, this was a problem in areas with strict noise regulations, but the problem is to clear this problem as the thickness of ice formed increases.

[0005]

Means for Solving the Problems The inventors of the present invention have made extensive studies in order to achieve the above objects. In general, when a refrigerant is sent to the inside of the freezing plate and water is sprayed and flows down from one side to form an ice layer on one side of the freezing plate, the heat transfer amount Q (kcal / hr) from the raw water side to the refrigerant side is It is as follows. Q = KA x (θ1-θ2) K: Heat transfer rate (kcal / m ² · hr · ° C), which is 1 / (1 / α ₁ + d ₁ / λ ₁ + d ₂ / λ ₂ + 1 / α ₂ ) α ₁ ; Refrigerant side surface heat transfer coefficient of flowing water layer (kcal / m ² · h
r ・ ° C) d ₁ ; Ice thickness (m) λ ₁ ; Ice thermal conductivity (kcal / m ・ hr ・ ° C) d ₂ ; Ice plate thickness (m) λ ₂ ; Ice plate heat conductivity ( kcal / m ・ hr ・ ° C) α ₂ ; Represented by the surface heat transfer coefficient of refrigerant (kcal / m ²・ hr ・ ° C), A: Freezing area (m ² ) θ1: Surface temperature of ice or flowing down Water temperature (° C) θ2: Refrigerant evaporation temperature inside the freezing plate (° C) Here, the K value naturally decreases as the thickness of the ice layer increases, and the A value depends on the size of the freezing plate. It can be regarded as a constant and θ1 is a few minutes after the start of ice making.
It becomes 0 ° C and remains constant thereafter. When the ice layer thickness increases and the K value decreases with the passage of ice-making time, and the Q value, which is the amount of heat transferred from the raw water side to the refrigerant side, decreases, the evaporating property of the refrigerant decreases, which causes the refrigerant suction of the refrigerator. The pressure decreases, and the θ2 value also decreases as the suction pressure decreases. That is, if the capacity of the refrigerator is high and the cooling capacity per ice plate is set high, the productivity will be improved, but the degree of decrease in the refrigerant suction pressure of the refrigerator will be large, which is (θ1
-Means that the temperature difference of θ2) becomes significant.

[0006] In the ice making machine of the above "Ai Star" series, the refrigerant suction pressure of the refrigerator 3.0 - set to 1.5kg / cm ^2, relatively high cooling capacity of the freezing plate by this 200
It has been selected within the range of 0 -2700 kcal / hr, and a plate-like ice piece with a standard thickness of 15 mm is formed by operating the ice-making process for 27 minutes. If the ice making time is extended to increase the thickness of the ice formed using the ice making machine, the temperature difference (θ1-θ2)
The ice may be partially cracked due to cracks that are thought to be caused by the above conditions.
It turned out that the limit is up to about m. The nozzle hole diameter of the water spray pipe in the above commercial ice maker is 4 mm and the nozzle pitch is 20 mm, but as the ice layer becomes thicker, the flow of water flowing down the surface changes and a flow path is created. It has been found that the growth of ice in this portion is delayed and the surface becomes uneven, which adversely affects the transparency of ice.

[0007] Therefore, the basic concept of the present invention is to
Compressor so that the cooling capacity per sheet is relatively low
By operating the (refrigerator), the difference between the evaporation temperature of the refrigerant on the inner surface of the freezing plate and the surface temperature of the formed ice, that is, the temperature of the raw material water flowing down on the surface of the ice, is prevented from becoming excessively large and gradually increased. The first object is to be achieved by increasing the thickness of the ice layer and appropriately setting the nozzle hole diameter and nozzle pitch of the sprinkler pipe.

That is, according to the present invention, the suction pressure of the refrigerant is
4.0-1.0 kg / cm ² Gradual change and ice plate
Operate the compressor so that the cooling capacity per sheet is 1000 kcal / hr ± 10%, and make the nozzle hole diameter of the sprinkler pipe 3.5 ± 2.0 m.
By setting m and the nozzle pitch to be 17.5 ± 3.0 mm, the above first objective can be achieved.

The above-mentioned second object is achieved by stopping water spraying at the end of ice making, then stopping the supply of the refrigerant and sucking the refrigerant in the freezing plate. In other words, it was surprisingly found that if the refrigerant in the freezing plate is sucked, the temperature inside the freezing plate drops sharply due to the principle of adiabatic expansion, but deicing occurs at this time.

The third purpose is to receive the plate-shaped ice pieces separated from the ice plate by the elevating arm in the horizontal state, lower the elevating arm carrying the plate-shaped ice, and then swing the object to the outlet. Achieved by guiding.

[0011]

The invention will now be described in more detail with reference to the drawings, which illustrate an ice making machine for carrying out the method of the invention. As shown in Figure 1, an ice machine 10
Is a coolant (not shown) liquid feeding / collecting unit 20 and an ice making unit 30.
And a crusher 50 for crushing the plate-shaped ice pieces into an appropriate size by crushing the plate-shaped ice pieces, and a water tank for raw water is provided below the receiving part 40. 60 are placed. This Figure 1 mainly shows the refrigerant circulation system.The liquid refrigerant sent from the refrigerant receiver 22 in the liquid sending / collecting section 20 passes through the pipe A, the stop valve B in the open state, and the solenoid valve C. Pipes for ice-making in the ice-making unit 30 that reach the expansion valve D, then vaporize through the evaporator E.
(Snaked pipe) From the lower inlet F1 of F to the upper outlet F2, and then collected, compressed via the pipe G by the compressor 24 of the liquid transfer / recovery section 20, and condensed via the pipe H to the condenser 26.
Then, it is made liquid again and then returned to the refrigerant receiver 22 through the pipe I. In the refrigerant sending / collecting unit 20, the device indicated by reference numeral 28 is the starter panel of the compressor 23, which is mounted outside the ice making machine 10 and is indicated by reference numeral 12. It is the control panel. In the plate-shaped ice piece receiving portion 40, as shown by the phantom line, an elevating arm 42 capable of ascending / descending and swinging motions, and the elevating arm together with the oblique passage of the plate-shaped ice piece to the crusher 50. There is a slanting plate 44 that forms the inside of the water tank 60.
Is arranged.

FIG. 2 shows a circulation system of raw water. Raw water supply (replenishment) The water sprinkled from the pipe 64, the raw water stored in the water tank 60 after passing through the lifting arm 42 having a watermark structure and the inclined plate 44, is stored in the water tank 60 by the submersible pump 62. One side of the ice plate 32 from the top of the ice plate 32 (described in detail later), which reaches the water spray pipes 66 through the valve K, the pipe L and the water collector M and is cooled by the refrigerant described in connection with FIG. 1. Be sprinkled on. Part of the sprayed raw material water freezes on the freezing plate 32, but the non-freezing raw water flows down along the surface of the freezing plate or the surface of the ice layer on the freezing plate, then falls freely and then goes up and down. The water is returned to the water tank 60 through the openings of the arm 42 and the slanting plate 44, and is circulated in the above manner. The branch pipe L1 provided in the pipe L is for opening the stop valve N and discharging the raw material water in the water tank 60 to the outlet pipe O.

The structure of the ice plate 32 and the manner of ice formation on the ice plate are shown in FIGS. 3 and 4. The ice board 32 is
It consists of a refrigerant serpentine pipe F in the ice making section from the lower inlet F1 to the upper outlet F2 via the evaporator E, and plate members 322 and 324 that are designed to sandwich the pipe F. And 324 have a waveform,
The pipe F is housed in the space formed between the wave heights of these plates. The upper part and the lower part of the ice plate 32 are bent so that the raw water from the sprinkler pipe 66 is sprayed only on one side of the ice plate. The plate members 322 and 324, which are the outer plates of the icing plate 32, are preferably made of stainless steel from the viewpoint of durability, and have a corrugated shape because the thickness of ice, which is the object of the present invention, is large. Yes, to prevent falling off during ice making.
The sprinkling pipe 66 is closed at both ends, and the raw water is supplied from almost the center of the sprinkling pipe 66, and small holes (not shown) are formed at a predetermined pitch in the upper part of the ice plate toward the bent part. The structure has a structure in which the raw material water is sprayed from the small holes to almost the entire surface of the freezing plate. Therefore, the lower entrance F1 of the ice board
To the upper outlet F2 from one side of the ice plate 32 cooled by the refrigerant vapor flowing through the serpentine pipe F.
The raw material water sprayed from 6 flows down almost the entire surface of the ice plate, and a part of it freezes, and if the raw water is continuously sprayed, as shown in Fig. 4, the ice layer on the ice plate surface will be formed. Is gradually increasing in thickness.

The structure of the ice making machine and the outline of the ice making mode are as described above. Next, the ice making method according to the present invention using the above ice making machine will be described in detail. First, the control panel 12
The raw water is stored in the water tank 60 through the raw water supply (supply) pipe 64 by operating (Figs. 1 and 2). Since the purpose of the present invention is to increase the thickness of the ice formed, the concentration of impurities that may be contained in the raw material water is increased, and the transparency of the ice formed by this is reduced. In order to prevent this from happening, the capacity of the water tank 60 is made much larger than that of the water tank in the conventional ice making machine for producing ice having a thickness of about 15 mm. Next, the submersible pump 62 in the water tank 60 is activated to flow the raw water from the sprinkler pipe 66 to the outer surface of the freezing plate 32, and the starter panel 28 is operated to operate the compressor 23 to circulate the refrigerant. Start ice making. In this case, the low-pressure side pressure of the compressor 23 is set to about 4 kg / cm ^2,
If the cooling capacity per ice cube plate 32 is set to about 1000 kcal / hr after the ice making time has elapsed, it takes about 4 hours to reach 50 mm in the thickness of the formed ice. Operate the compressor 23 so that the low-pressure side pressure does not drop below 1.0 kg / cm ² . When the above ice making time has elapsed, the submersible pump 62 is stopped to stop the supply of the raw material water and the supply of the refrigerant. Then, the solenoid valve C (Fig. 1) is closed, and the compressor 24 is operated to suck the refrigerant inside the freezing plate 32 to drastically lower the internal temperature of the freezing plate 32. Plate-shaped ice pieces peel off and fall. 1 and 2, the plate-like ice pieces are received by the elevating arm 42 in the solid line position, that is, the horizontal / upper position, and then the elevating arm is lowered horizontally (to the first imaginary line position). By slowly swinging (to the position of the second virtual line), the plate-like ice pieces carried by the elevating arm 42 are slid down and crushed by the crusher 50 to obtain ice crushed to a desired size. As described above, the free-falling distance of the plate-shaped ice pieces is extremely short, and since the ice pieces are guided to the crusher in such a manner that they slide down after reaching a low position, almost no impact noise is generated in connection with deicing.

In the method of the present invention, the deicing system is different from the conventional thermal system (combined use of hot water and hot gas).
Since it is a dry type, fine ice pieces remain on the surface of the freezing plate 32, especially at both ends, so after the crushed ice is taken out,
Sprinkle water from the raw water supply (supply) pipe 64 and drop it into the water tank 60.

Comparative Production Example The above-mentioned ice making method according to the present invention and the conventional “Iister”
(Trademark) ice making method was used to make ice. The ice making conditions and results were as shown in Table 1 below.

[0017]

[Table 1] The heat transfer rate (K value) decreases as the thickness of ice increases, and the amount of heat transferred (Q value) from the falling raw water side to the refrigerant side also decreases, but the relationship between ice thickness and K value is as follows. As shown in Table 2, the K value in the vicinity of 15 mm is 40-
2.8-3.5 times the value near 50 mm, with a thickness of 1
At about 5 mm, the ice formed does not crack due to temperature differences, so the output of the compressor (refrigerator) can be set high to increase the cooling capacity of the freezing plate. Although there are more methods (about 2.4 times), the method of the present invention produces better output per 1KW of power consumption.
(More than 10%), so there is no particular difference in productivity between the two. The crushed ice produced by either method is extremely excellent in flatness and transparency, and the essential difference between the two is only the size.

[0018]

[Table 2]

[0019]

EFFECTS OF THE INVENTION According to the present invention, ice having excellent transparency and surface smoothness similar to the conventional ones and having a large thickness and versatility can be efficiently produced. De-icing is easy and no noise is generated during the de-icing process.

[Brief description of drawings]

1 is a schematic view showing an apparatus for carrying out an ice making method according to the present invention, and is a side view showing a refrigerant circulation system in particular.

FIG. 2 is a vertical cross-sectional view showing an ice making section of the apparatus in FIG. 1, particularly a drawing showing a supply circulation system of raw material water.

FIG. 3 is a side view of an ice plate used in the apparatus of FIGS. 1 and 2.

FIG. 4 is a cross-sectional view schematically showing a state during ice making.

[Explanation of symbols]

 10: Ice maker 12; Control panel 20: Refrigerant delivery / recovery section 22; Refrigerant receiver 24; Compressor (refrigerator) 26; Condenser 30: Ice making section 32; Ice plates 322, 324; Plate 40: Plate Ice piece receiver 42; Lifting arm 44; Oblique plate 50: Crusher 60: Water tank for raw water 62; Submersible pump 64; Raw water supply / supply pipe 66; Sprinkling pipe

Claims (4)

[Claims] 1. An ice making method in which raw material water is circulated to an ice-making plate to form and grow an ice layer on the ice-making plate, and the formed plate-like ice pieces are deiced and crushed into crushed ice. , So that the suction pressure of the refrigerant gradually changes from 4.0 to 1.0 kg / cm ² and the cooling capacity per ice plate is 1000 kcal / hr ± 10%
Operate the compressor so that
An ice making method characterized by setting the nozzle pitch to 3.5 ± 2.0 mm and the nozzle pitch to 17.5 ± 3.0 mm. 2. The ice making method according to claim 1, wherein deicing is performed by stopping water spraying at the end of ice making, then stopping the supply of the refrigerant, and sucking the refrigerant in the freezing plate. 3. A plate-like ice piece separated from an ice plate is received by a horizontal elevating arm, the elevating arm carrying the plate-like ice is lowered, and then a swing motion is conducted to guide it to the outlet. The method for making ice according to claim 1 or 2. 4. A refrigerant liquid sending / collecting unit, an ice making unit provided with an ice plate, and a refrigerant circulation path from the refrigerant liquid sending / collecting unit to the refrigerant liquid sending / collecting unit via the ice making unit. And a sprinkling pipe arranged near the upper part of the freezing plate, the raw water is circulated to the sprinkling pipe so that the water flows down on the surface of the freezing plate. In an ice making device that forms and grows an ice layer on a plate, the above sprinkling pipe has multiple nozzle holes, and each nozzle hole diameter is 3.5
The ice making device, which is ± 2.0 mm and has a nozzle pitch of 17.5 ± 3.0 mm.