JP2000258004A - Ice making unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ice making unit provided, in a casing, with a plurality of liquid passages for passing a solution producing ice through heat exchange with a refrigerant in which a large quantity of high quality uniform ice can be produced regardless of outer air conditions by flowing the solution at a uniform rate through the plurality of liquid passages thereby eliminating the need of stirring the solution through bubbling according to prior art. SOLUTION: In an ice making unit arranged to make ice from a solution flowing through liquid passages 10, 10a, 10h in a casing through heat exchange with a refrigerant flowing through a refrigerant passage 20, the liquid passages 10, 10a, 10h are formed as a plurality of parallel passages by sectioning the casing. The plurality of liquid passages 10, 10a, 10h are deflected at the upper and lower ends to communicate each other thus constituting a single continuous conduction passage extending a liquid inlet 15 made in the casing 3 to a liquid outlet 16 while passing the plurality of liquid passages 10, 10a, 10h sequentially. Furthermore, covers 8a, 8b for opening/closing the liquid passages 10 with respect to an ice take-out section are provided above the upper deflecting section in the casing 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice maker in which a plurality of liquid passages through which a solution for generating ice by heat exchange with a refrigerant flows through a casing are formed as a single continuous liquid passage.

[0002]

2. Description of the Related Art In an ice maker that precipitates ice crystals from an aqueous solution by heat exchange between an aqueous solution and a refrigerant in a supercooled state, the efficiency of the refrigerant is increased by increasing the flow rate of the refrigerant and rapidly evaporating the refrigerant. There is an invention proposed by the present applicant in Japanese Patent Application No. Hei 9-200769 as an ice making device which enables ice making and, moreover, enables quick and efficient execution of the freeze concentration process.

[0003] In this invention, the outer cylinder having a hollow portion and a concave portion communicating with the hollow portion inside the upper and lower ends and the hollow portion through a gap of about 0.5 to 2.0 mm. And an inner cylinder having an uneven surface on the outer periphery and having upper and lower ends protruding from the recess, wherein the outer cylinder has a refrigerant inlet opening to the upper recess, and a refrigerant discharge opening to the lower recess. An outlet is provided, and a cooling water introduction port communicating with the inside of the inner cylinder is provided above the outer cylinder, and a refrigerant is passed from the refrigerant introduction port through the upper concave portion to the minute gap to the refrigerant discharge port. Guiding and simultaneously allowing ice water to precipitate on the inner wall surface of the inner cylinder while simultaneously lowering the cooling water along the inner wall surface of the inner cylinder from above, further comprising a plurality of hollow portions in the outer cylinder, Through a gap of about 0.5 to 2.0 mm It is inserted through the serial inner cylinder.

[0004] In the present invention, the refrigerant flows through the minute gap between the hollow portion of the outer cylinder and the inner cylinder due to the above configuration. In the minute gap, the refrigerant evaporates quickly. At the same time, the refrigerant evaporates quickly on the uneven surface on the outer periphery of the inner cylinder, thereby increasing the heat transfer efficiency. By guiding the coolant to the minute gap through the recess for introducing the coolant in the outer cylinder, the coolant is appropriately distributed by the recess. Thereby, efficient freezing and concentration is realized.

[0005]

In such prior art, a solution is accommodated in a plurality of inner cylinders, and the solution is caused to flow down in the inner cylinder while stirring (bubbling) the solution with air.
Since ice is generated by exchanging heat with the refrigerant flowing through the refrigerant passage outside the inner cylinder, the amount of ice generated is easily affected by the outside air in the ice generation, and in the summer and winter when the temperature difference is large. And quality tend to differ.

Further, in such a conventional technique, the flow speed of the solution in the plurality of solution passages provided in the inner cylinder tends to fluctuate, whereby the amount of heat exchange with the refrigerant also fluctuates in each passage. As a result, there is also a problem that the amount and quality of ice generated in each passage are not uniform.

The present invention has been made in view of the above-mentioned problems in the prior art. In an ice maker provided with a plurality of liquid passages in a casing through which a solution for generating ice by heat exchange with a refrigerant flows, the plurality of liquid passages are provided. Ice making that allows each solution to flow at a uniform speed and eliminates the need for stirring by bubbling as in the prior art, making it possible to produce large quantities of uniform and high-quality ice without being affected by the outside air condition The purpose is to provide a vessel.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a first aspect of the present invention, wherein a solution flowing through a liquid passage formed inside a casing is formed with a wall separated from the liquid passage. In the ice maker configured to generate heat from the solution by exchanging heat with the refrigerant flowing through the refrigerant passage, the liquid passage is formed by dividing the casing into a plurality of planes in a plane direction. It is formed in a parallel passage, and the plurality of liquid passages are deflected at the upper end and the lower end to communicate with each other, and sequentially from the liquid inlet provided in the casing through the plurality of liquid passages to the liquid outlet. An ice making device comprising a single continuous communication path connected to the casing, and a lid for opening and closing the liquid passage and the ice extraction section provided above the upper turning portion of the casing. Suggest a bowl.

A second aspect of the present invention relates to a specific structure of the casing according to the first aspect of the present invention. In the first aspect, the casing is provided with the plurality of liquid passages and the liquid passage and a wall. A main body casing provided with a refrigerant passage for allowing a refrigerant to flow therethrough, and a turning portion fixed on an upper portion of the main body casing and provided on an upper side of the solution flowing through the plurality of liquid passages, An upper casing provided with a connecting / disconnecting portion for the lid at an upper portion, and a lower casing fixed to a lower portion of the main casing and provided with a lower-side turning portion of the solution flowing through the plurality of liquid passages. Become.

In this invention, the plurality of liquid passages are formed in a hollow portion formed by dividing the casing so as to form the passage in a vertical direction (vertical direction). And a coolant passage is formed between the outer peripheral surface of the inner cylinder and the partition wall of the hollow portion. It is preferable that the refrigerant flows with a cross-current component in the flow direction of the solution flowing in the inner cylinder.

It is preferable that the outer peripheral surface of each of the inner cylinders has an uneven surface to increase the heat transfer area for heat exchange with the refrigerant.

In this invention, the plurality of liquid passages provided in the casing are formed in the casing so as to have a width in the plane perpendicular to the direction of flow of the solution.
The casing is provided in a plurality of rows in the depth direction, the solution is introduced from one of the outer walls of the casing, and the communication paths are flowed in series, and then the liquid is led out from the other of the two rows. Is preferred.

According to a third aspect of the invention, there is provided the lid according to the first or second aspect, wherein a refrigerant passage through which a refrigerant flows is provided in the vicinity of the connecting / disconnecting portion between the lid and the casing. .

[0014] According to a fourth aspect of the present invention, in the third aspect, the refrigerant passage is provided in an inside of the upper casing close to a surface where the upper casing is connected to and detached from the lid, and in the inside of the lid.

According to this invention, the solution enters one of the plurality of liquid passages from the liquid inlet provided on the outer wall of the casing, and changes its direction at the diverting portions of the upper casing and the lower casing. The plurality of liquid passages and the plurality of liquid passages of the upper casing and the lower casing flow in series and in one direction.

The solution exchanges heat with the refrigerant flowing through the refrigerant passage formed across the wall of the liquid passage while flowing in the plurality of liquid passages in one direction. At the time of such heat exchange, the water in the solution precipitates as ice crystals inside the respective liquid passages maintained at the supercooling temperature by the refrigerant and is laminated in a plate shape, and plate ice is formed on the inner wall of the passage. Is done.

In this invention, since the plurality of liquid passages are formed as a single continuous one-way flow communication passage, the flow velocity of the solution can be kept uniform over the entire length of the liquid passage. The heat exchange with the refrigerant is uniformly performed in all the liquid passages, and the ice generated in each liquid passage has a uniform quality and a uniform generation amount.

According to the third and fourth aspects of the present invention, each liquid passage is configured to be opened and closed by a lid that can be opened and closed by controlling the refrigerant temperature. By closing, the liquid passage in the casing is shut off from the outside air, and as described above, the plurality of liquid passages can be configured as a single continuous one-way flow communication passage, thereby reducing the influence of the outside air condition. Ice can be manufactured without receiving it, and ice with stable quality can be manufactured.

As for the opening and closing of the lid, since the refrigerant passage is provided near the connecting / disconnecting portion between the lid and the casing and inside the lid as described in the third and fourth aspects, the lid and the casing are not connected during ice making. The connecting / disconnecting portion is fixed by being frozen by a low-temperature refrigerant, so that the liquid passage and the outside air are shut off, so that the above-described ice making operation is not affected by the outside air.

Further, when the liquid surface of the liquid passage is held near the lid and the temperature of the refrigerant is raised by using the refrigerant circuit as a heat pump circuit, the connection / disconnection portion between the lid and the casing frozen as described above is formed. As the ice melts, the ice in the liquid passage is separated from the passage wall and rises above the liquid surface due to the temperature rise of the refrigerant. Then, the lid is opened by the buoyancy of the ice, and the ice is extruded into an ice outlet duct, cut by a crusher and sent to a use destination. Therefore, the lid can be automatically opened and closed by switching the refrigerant circuit between the refrigeration cycle and the heat pump cycle.

Further, at the time of ice making, since each liquid passage is constituted as a single continuous communication passage as described above, and ice can be made only by circulating the solution by using a pump, the conventional technique is used. Equipment such as a compressor and an air tank for supplying the bubbling air is not required at all, and the apparatus cost is reduced, and only the energy for driving the pump for circulating the solution through the liquid passage at a moderate speed is used. And energy costs are reduced.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not merely intended to limit the scope of the present invention, but are merely illustrative examples unless otherwise specified. Absent.

FIG. 1 is a longitudinal sectional view (a sectional view taken along line AA of FIG. 4) of an ice maker according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a lid mounting portion, and FIG. FIG. 4 is a view of FIG.
FIG. 5 is an exploded perspective view showing the structure of the casing and the flow of the solution.

In FIG. 1, 1 is a main casing, 2 is an upper casing, and 3 is a lower casing. The upper casing 2 is fixed to an upper flange 1a of the main casing 1 by a plurality of bolts (not shown). The casing 3 is fixed to the lower flange 1b of the main casing 1 with a plurality of bolts (not shown).

As shown in FIG. 4, a plurality of (eight in this embodiment) hollow portions 32 are formed in the main body casing 1 in parallel with its longitudinal direction (vertical direction). And each hollow part 32 is mutually connected by the passage 32a. In each hollow portion 32, an inner cylinder 15 having an outer periphery formed with an uneven surface for expanding a heat transfer area is provided with an inner wall surface 16 of the hollow portion 32.
And a gap which becomes a refrigerant passage 20 described later. Further, the liquid passages 10a, 10b, 10c, 10d,.
.. 10h are formed.

The liquid passages 10a, 1
.. 10h are arranged in two rows in the width direction and four rows (not necessarily four rows) in the depth direction as shown in FIG. 5, and each of the liquid passages 10a, 10b,. The upper opening and the lower opening of the liquid passage 10 of the upper casing 2 and the liquid passage 1 of the lower casing 1 will be described later.
It is connected to 0.

Reference numeral 20 denotes a refrigerant passage. The refrigerant passage 20
In the main body casing 1, the outer peripheral surface (the uneven surface 16) of the inner cylinder 15 inserted into each of the hollow portions 32 and the hollow portion 3
2 is provided over the entire length of the main body casing 1 and the hollow portions 12 communicate with each other through the passages 32a.
In the direction of the paper surface of FIG.

Each liquid passage 10a, 10b,... 1 in the inner cylinder 15 of the main casing is provided in the lower casing 3.
The liquid passage 10 is provided so as to extend downward from 0h. The liquid passage 10 communicates with each of the liquid passages 10a, 10b,... 10h of the main body casing 1 as shown in FIG. 10b and 10c, 10d and 10e,
, And 10 f and 10 g are in communication with each other.

In the lower casing 3, a liquid inlet 15a is provided at a lower portion of the liquid passage 10 which communicates with the liquid passage 10a from the outer wall of the main casing 1, and communicates with a liquid passage 10h of the main casing 1. Liquid passage 1
A liquid outlet 16a is provided at the lower part of 0. A wall 3 is provided around the liquid passages 10 of the lower casing 3.
A refrigerant passage 20 is provided with a space therebetween, and the refrigerant passage 20 communicates with the refrigerant passage 20 of the main body casing.

On the other hand, although not shown, the upper casing 2 has a liquid passage 1 in the lower casing 3 as shown in FIG.
0, the solution flow is applied to the lid 8a of the upper casing 2;
8b, 10a and 10b, 10c and 10d, 10e and 10
f, four liquid passages 10 are provided such that 10 g and 10 h communicate with each other. Outside the liquid passages 10 of the upper casing 2, a refrigerant chamber 2 through which a refrigerant flows is provided.
1 and 25 are provided, the outer refrigerant chamber 21 is communicated with the outer refrigerant passage 20 of the main casing 1, and the central refrigerant chamber 25 is communicated with the central refrigerant passage 20 of the main casing 1.

Numeral 17 denotes a refrigerant inlet, and the upper casing 2
And is connected to the refrigerant passage 20 in the main body casing 1 via the refrigerant chamber 25 of the upper casing 2. Reference numeral 18 denotes a refrigerant outlet, which opens into a refrigerant passage 21 at the center of the lower casing 3 and is connected to the refrigerant passage 20 of the main casing 1 via the refrigerant passage 21.

8a and 8b are lids. The lid 8a, 8
b is adapted to be connected to and detached from the upper surface of the upper casing 2 to open and close the liquid passage 10 of the upper casing 2. As shown in FIGS. 1 to 3, the lids 8 a and 8 b are rotatably supported around the support shaft 9 via a support shaft 9 attached to an upper portion of the upper casing 2.

The inside of the lids 8a and 8b is shown in FIG.
As shown in FIG. 3, a refrigerant chamber 19 through which the refrigerant flows is formed. In FIG. 3, reference numeral 26a denotes a refrigerant pipe for introducing refrigerant into the refrigerant chamber 19, and 26b denotes a refrigerant pipe for leading refrigerant in the refrigerant chamber 19.

In FIG. 2, V-shaped grooves 26, 26 for introducing moisture are provided on the contact surface 27 of the upper casing 2 with the lids 8a, 8b in the depth direction (the axial center of the support shaft 9). Direction). Further, the refrigerant chamber 25 of the upper casing 2 and the refrigerant chamber 19 of the lids 8a and 8b are provided as close as possible to the connecting / disconnecting surface 27 and the V-shaped groove 26. It can be cooled or heated effectively.

In FIG. 1, 13 is a liquid inlet pipe connected to the liquid inlet 15a of the lower casing 3, 14 is a liquid discharge pipe connected to the liquid outlet 16a, 11 is a liquid tank, 12 is a liquid tank.
Is a liquid pump, which sends out a solution from the liquid inlet pipe 13 to the liquid inlet 15a by the liquid pump 12, and circulates a solution from the liquid outlet 16a to the liquid discharge pipe 14 and the liquid tank 11 to the liquid passage 10. Make up.

Reference numeral 4 denotes an ice take-out duct, in which a crusher 6 for breaking the plate ice generated in the liquid passage 10 is rotatably provided by a drive shaft 7. 5 and 5 are covers provided near the lids 8a and 8b.

In the ice maker having such a configuration, the refrigerant introduced from the refrigerant inlet 17 of the upper casing 2 fills the refrigerant chambers 21 and 25 in the upper casing 2. The coolant cools the wall of the liquid passage 10 in the upper casing 2 to maintain the liquid passage 10 at a subcooling temperature, and connects and detaches the cooling chamber 25 with the upper lids 8a and 8b. 27 and the vicinity of the V-shaped groove 26 are cooled.

The refrigerant is circulated through the refrigerant pipes 26a and 26b in the refrigerant chamber 19 of the lids 8a and 8b to cool the vicinity of the connecting / disconnecting surface 27. As a result, the moisture accumulated in the groove 26 and the moisture adhering to the connecting / disconnecting surface 27 are frozen, and the lids 8a and 8b
It is completely fixed to the upper casing 2.

On the other hand, the refrigerant introduced into the refrigerant chambers 21 and 25 enters the refrigerant passage 20 in the main casing 1. Then, as shown in FIG. 4, the refrigerant flows through the refrigerant passage 20 formed around the outer periphery of the inner cylinder 15 provided in each hollow portion 32,
The inner cylinder 15 is cooled through the uneven surface 16 of the inner cylinder 15, and the liquid passages 10a, 10b,... At this time, since the outer surface of the inner cylinder 15 is formed on the uneven surface 16, the heat transfer area increases, the flow velocity increases, and the heat transfer efficiency increases.
Is cooled efficiently.

The refrigerant passage 2 of the main casing 1
The refrigerant having passed through the lower casing 3 flows down into the refrigerant passage 21 of the lower casing 3, and flows through the liquid passage 10 of the lower casing 3.
The liquid passage 10 is cooled to a subcooling temperature by cooling the wall of the liquid passage, and then discharged from the refrigerant outlet 18.

On the other hand, the solution that has entered the liquid passage 10 of the lower casing 3 from the liquid inlet 15 of the lower casing 3 (in this example, the solution will be described as an ice slurry containing grain ice generated by a grain ice forming device). The liquid passage 1 of the lower casing 3 maintained at a supercooling temperature by the refrigerant.
0, liquid passages 10a, 10b in body casing 1 ... 1
0h, and flows in series in the liquid passage 10 in the upper casing 2.

That is, as shown by the arrow in FIG. 5, the solution enters the liquid passage 10a of the main casing 1 from the liquid passage 10 of the lower casing 3 and rises there.
In the liquid passage 10 of the main body 1, it is turned downward by the inner surfaces of the lids 8 a and 8 b and enters the liquid passage 10 b of the main casing 1. Further, the solution enters the liquid passage 10 of the lower casing 3 from the liquid passage 10b, is turned upward at the inner surface of the bottom of the lower casing 3, and enters the main casing 1C. Such a flow of the solution flows through the liquid passage 10 in the main casing.
d, 10e, 10f, 10g, and 10h, as a continuous one-way flow passing in this order, to generate ice as described later,
The solution having a high concentration passes through a liquid outlet 16a provided at the bottom of the lower casing 3 through a liquid discharge pipe 14, and is supplied to the liquid tank 1
The mixture is discharged to 1 and mixed with the original solution, and is again sent to the liquid inlet 15a by the pump 12.

In the flow of the solution, as shown in FIG. 4, the solution is maintained at a supercooled temperature in a liquid passage 10a in the inner cylinder 15 (the liquid passage 10a will be described below, but the liquid passages 10b, 10c ,... 10h), the water contained in the solution precipitates as ice crystals 30, and this gradually accumulates in the form of a plate, and the solution 10a
A plate-like ice 31 is deposited on the wall surface of the inner cylinder 15, that is, on the inner wall surface of the inner cylinder 15. Furthermore, the fine ice crystals 30 are
Since the freezing point is lower than 1, the latent heat is discharged from the liquid passage 10a to be melted and adhere to the surface of the sheet ice 31. Since the latent heat at the time of melting is used for generating new ice, the thickness of the sheet ice 31 is increased, and the productivity thereof is improved.

As described above, in the present invention, heat exchange with the refrigerant is uniformly performed in the plurality of liquid passages 10, 10a, 10b,..., 10h, and the production of the sheet ice 31 is not affected by the outside air. Can be performed, and plate ice 31 of uniform quality can be manufactured.

When the plate ice 31 is manufactured as described above and is taken out from the liquid passages 10, 10a, 10b,..., 10h, the refrigerant circuit is switched from the refrigeration cycle to the heat pump cycle. As a result, the heated refrigerant is sent to each of the refrigerant passages 20, 21, 25 and the like, and the inner cylinder 15 is heated to an appropriate temperature, and the sheet ice 31 is separated from the inner surface of the inner cylinder 15 and floats on the liquid surface.

On the other hand, the refrigerant whose temperature has been raised as described above is also introduced into the refrigerant chamber 25 and the refrigerant chamber 19 of the lids 8a and 8b, and melts the ice of the connecting / disconnecting surfaces 27 and the grooves 26 of the lids 8a and 8b. Let me know. As a result, the lids 8a and 8b are rotatable around the support shaft 9, and the liquid passages 10, 10a, 10b,...
The plate ice 31 within 10 h is pushed into the ice extraction duct 4, cut by the crusher 6, and sent to a use destination such as a heat storage tank.

By switching the refrigerant cycle to the refrigerating cycle when producing ice and the heat pump cycle when removing ice as described above, the lids 8a and 8b can be automatically opened and closed, and the above-described external air Ice making with unaffected unidirectional flow of solution is possible.

[0048]

As described above, according to the present invention, according to the present invention, the liquid passage formed in the casing and in which plate ice is generated is automatically closed by the lid during ice making and shut off from outside air, and when the ice is taken out. In addition to being able to open, the liquid passage is a continuous one-way flow communication passage, so that the flow rate of the solution is uniform, heat exchange with the refrigerant is uniform in all passages, and ice is not affected by outside air. Can be manufactured. As a result, a large amount of ice of stable quality can be produced, the ice making efficiency can be improved, and high quality ice can be obtained.

In addition, the need for bubbling with air as in the prior art is unnecessary, and only power for circulating the solution by the pump is used.
A device for producing the air is not required, and the cost of the device is reduced.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view (a sectional view taken along line AA in FIG. 4) of an ice maker according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a lid mounting portion in the embodiment.

FIG. 3 is a view taken in the direction of arrow C in FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 1;

FIG. 5 is an exploded view showing a structure of a casing and a flow of a solution in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body casing 2 Upper casing 3 Lower casing 4 Ice extraction duct 5 Cover 6 Crusher 7 Drive shaft 8a, 8b Lid 9 Support shaft 10, 10b, 10c ... 10h Liquid passage 11 Liquid tank 12 Liquid pump 13 Liquid inlet pipe 14 Liquid Discharge pipe 15a Liquid inlet 16a Liquid outlet 17 Refrigerant inlet 18 Refrigerant outlet 19 Refrigerant chamber 20 Refrigerant chamber 21 Refrigerant chamber 25 Refrigerant chamber 30 Ice crystal 31 Sheet ice 32 Hollow part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kuniharu Yoshimura 3-2-2, Nakanoshima, Kita-ku, Osaka-shi Inside Kansai Electric Power Co., Inc. (72) Tadashi Nozawa 15-1, Ushijima-cho, Toyama-shi Hokuriku Electric Power Company Inside the company (72) Inventor Tetsuo Nakayama 15-1, Ushijima-cho, Toyama City Hokuriku Electric Power Co., Inc. (72) Inventor Shigeru Sakashita 2-13-1, Botan, Koto-ku, Tokyo Co., Ltd.

Claims (4)

[Claims] 1. Heat exchange between a solution flowing through a liquid passage formed inside a casing and a refrigerant flowing through a refrigerant passage formed by separating the liquid passage from a wall to generate ice from the solution. In the ice maker configured as described above, the liquid passage is formed as a plurality of parallel passages that divide the casing into a plurality of sections in a plane direction, and the plurality of liquid passages are formed at an upper end and a lower end. Deflected and communicated to form a single continuous communication path that is connected to the liquid outlet by sequentially passing through the plurality of liquid passages from the liquid inlet provided in the casing, and further includes the upper part of the casing. An ice maker, wherein a lid for opening and closing between the liquid passage and the ice take-out part is provided above the turning part. 2. The main body casing, wherein the casing is provided with the plurality of liquid passages, and provided with a refrigerant passage for allowing a refrigerant to flow through the liquid passage and a wall.
An upper casing fixed to an upper portion of the main body casing and provided with an upper-side turning portion for the solution flowing through the plurality of liquid passages, and an upper portion provided with a connecting / disconnecting portion with the lid; 2. The ice maker according to claim 1, further comprising: a lower casing fixed to the lower casing and provided with a diverting portion on a lower side of the solution flowing through the plurality of liquid passages. 3. The ice maker according to claim 1, wherein a refrigerant passage through which the refrigerant flows is provided in proximity to the connecting / disconnecting portion between the lid and the casing. 4. The ice maker according to claim 3, wherein the refrigerant passage is provided inside the lid close to a surface of the upper casing connected to and detached from the lid, and inside the lid.