JP2003106716A - Ice making method and ice making device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the phase change, when the supercooling state is cancelled in a closed canceller, from being introduced to a connecting tube upstream. SOLUTION: Supercooling water from a supercooler 2 flows into a closed canceller 4 via a connecting tube 3. The connecting tube 3 is divided in an outside vessel 22. In the outside vessel 22, water that is 0 deg.C or higher is injected from a water injection pipe 21 and goes into the connecting tube 3 from a gap d. A water liquid film is formed on a wall surface in the downstream connecting tube 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously eliminating supercooled water to make ice, and for preventing the production of supercooled water over a long period of time, and an apparatus capable of continuously making ice. Is.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a method for producing ice by continuously releasing water in a supercooled state in a closed pipe. It is necessary to prevent the phase change (release of supercooling) from propagating from the existing ice-making container to the cooler and avoid freezing of the cooler.

That is, when the supercooled water produced in the supercooler begins to undergo a phase change in the canceller, ice nuclei are repeatedly grown and separated on the wall surface in the canceller. The phenomenon of ice growth and separation on the solid surface in contact with the supercooled water propagates through the inner wall of the connecting pipe connected to the inlet of the release device to the upstream side, that is, the subcooler side. The reason for such propagation is related to the adhesion of ice to the wall.
That is, even if the ice attached to the wall surface is exposed to a high-speed flow, it remains stationary with respect to the pipe wall while moving, or moves toward the downstream side at an extremely slow speed. Since it is a state, the phase change advances upstream by the amount of ice growth during that time. Even if peeling occurs due to the flow, microscopic crystal groups remain on the original bonding surface, and new ice nuclei grow from there.

In this regard, for example, Japanese Patent No. 280615
No. 5 discloses a method of preventing the propagation of phase change by heating a connecting pipe, and JP-A-20-209
In 00-74532, a method is proposed in which the end of the connecting pipe on the ice making container side is specially processed to increase the flow velocity to 2.7 m / s or more to prevent ice from entering the connecting pipe.

Furthermore, as a method for weakening the adhesion of ice to the wall surface in the releaser, as disclosed in the proceedings of the 35th Heat Transfer Symposium (1998, P.221), the wall material itself is used. There is also a method of using a material having a low thermal conductivity.

[0006]

However, the technique disclosed in Japanese Patent No. 2806155 requires additional energy for heating and avoids a decrease in the amount of ice making due to an increase in the temperature of the supercooled water. There is a problem that there is no.

On the other hand, in the technique disclosed in Japanese Unexamined Patent Publication No. 2000-74532, the pipe resistance of the connecting pipe is increased by increasing the flow velocity of the connecting pipe, so that the energy for carrying water and the produced ice water does not increase the flow velocity. It is needed more than in the case. In order to maintain the effect that the phase change does not propagate to the upstream side for a long period of time, separate measures must be taken to prevent foreign matters such as fine scratches and scales from sticking to the specially processed surface of the connecting pipe end. Need to take action.

Also, the method of using a material having a small thermal conductivity as the wall material itself cannot make the adhesive force of ice to 0 because there is no substance having a thermal conductivity of 0, and therefore the phase change is caused. Cannot be completely prevented from propagating upstream.

The present invention has been made in view of the above points, and in the production of ice by releasing supercooling in a so-called closed system, the above-mentioned special heating energy for preventing propagation and the end portion of the connecting pipe. The present invention provides an ice making method and an ice making device which can stably prevent the phase change from propagating from a release device to a connecting pipe for a long period of time without requiring any special processing on the surface, thereby solving the above problems. Its purpose is to achieve.

[0010]

In order to achieve the above-mentioned object, the method for producing ice according to the present invention is to release supercooled water from a closed system without contacting the air, which has been supercooled by a supercooler, with the atmosphere through a connecting pipe. In the method for producing ice by sending it to a vessel, water at 0 ° C. or higher is supplied to the entire circumference of the inner wall surface of the connecting pipe.

As the water having a temperature of 0 ° C. or higher, water immediately before entering the subcooler or water after heating the water taken from the heat storage tank can be used. Of course, water exceeding 0 ° C may be used.

When water having a temperature of 0 ° C. or higher is supplied to the entire inner wall surface of the connecting pipe, a liquid film of water having a temperature of 0 ° C. or higher is formed on the entire inner wall surface of the connector downstream of the supplied portion. It This liquid film can prevent ice from adhering to the inner wall of the connecting pipe and propagating the phase change to the upstream side. In addition, even if ice nuclei are present, they do not grow inside the liquid film formed on the wall surface above 0 ° C, and eventually they melt or flow to the downstream, so that a phase change occurs in the connecting pipe. It does not propagate to the upstream side beyond the part where hydration above ℃ is being supplied. In order to obtain the above effects, it is necessary to maintain the flow rate from the outlet of the connecting pipe at about 2% to 3% of the flow rate of water flowing into the release device. The flow velocity in the connecting pipe is 1 m / s.
The above is sufficient.

The ice making device of the present invention comprises a subcooler for bringing water into a supercooled state, a closed system releaser for releasing water in a supercooled state, an outlet of the subcooler and the releaser. An ice manufacturing device having a connecting pipe connecting an inlet, comprising: an outer container watertightly covering the outer periphery of the connecting pipe; and a water injection pipe for injecting water into the outer container, wherein the connection is made in the outer container. The pipe is characterized in that it is divided over the entire circumference through a gap.

According to the ice making device having such a configuration, since the connecting pipe is divided over the entire circumference in the outer container through the void, when water is injected from the water injection pipe into the outer container, the connecting pipe is released from the void. It is possible to form a liquid film of water injected from the gap to the inner wall of the connecting pipe on the downstream side by supplying water to the inner wall of the. Therefore, the ice manufacturing method of the present invention can be preferably implemented. The disconnection of the connecting pipe is slightly mitigated by the gap when ice pieces start to form on the connecting pipe from the release device. However, since the bridge action works, it cannot completely prevent the propagation to the upstream side.

The water injection pipe branches from an introduction pipe connected to the inlet side of the subcooler to bypass the subcooler,
If it is connected to the external container, it is not necessary to secure a separate water source, and the temperature of water to be poured is appropriate, or a small amount of heat is required even if heated.

The divided end surface of the connecting pipe has a taper shape in which the inner wall side of the end surface of the upstream connecting pipe projects toward the downstream side, and the outer wall side of the end surface of the downstream connecting pipe projects toward the upstream side. It is preferably tapered. The inner wall side of the end face of the upstream connecting pipe is tapered so that the outer wall side of the end face of the downstream connecting pipe projects toward the upstream side, and the end face of the downstream connecting pipe itself is the upstream side. It may be molded so as to be convexly curved toward. Further, the inner wall side of the end face of the upstream connecting pipe projects downstream from the outer wall side, the inner wall side of the end face of the downstream connecting pipe projects upstream from the outer wall side, and the inner wall side tip of each end face extends in the axial direction. It may have a surface perpendicular to it. The inner wall side of the end face of the upstream connecting pipe projects downstream from the outer wall side, the inner wall side of the end face of the downstream connecting pipe projects upstream from the outer wall side, and each end face itself faces outward of the connecting pipe. Those that are convexly curved can also be suitably used.

By forming the divided end surface of the connecting pipe as described above, it is possible to suitably form a liquid film on the inner wall of the connecting pipe by the water injected from the water injection pipe.

A heater for heating the water flowing in the introducing pipe or a temperature controller for adjusting the temperature of the water flowing in the introducing pipe is provided upstream of the connection portion of the water introducing pipe in the introducing pipe. May be This makes it possible to make the water injected into the outer container more appropriate.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the entire structure of the ice making device 1 according to the present embodiment. The subcooler 2 has, for example, a so-called shell-and-tube structure, and is introduced into the subcooler 2. It has a function of cooling water with brine from a refrigerator (not shown) to bring the water into a supercooled state of, for example, 0 ° C. or lower.

The outlet side of the subcooler 2, that is, the outlet 2a
Is connected to one end of the connecting pipe 3, and the other end of the connecting pipe 3 is connected to the hermetic release device 4. The release device 4 is
It has a function of releasing the supercooled state of the supercooled water that has flowed in through the connecting pipe 3, changing the phase of the supercooled water, generating ice in the form of slurry, and flowing the ice to the outside. As a trigger for releasing supercooling, for example, an ultrasonic wave from an ultrasonic transducer is used.
As this type of closed-type release device 4, a known device can be appropriately used.

An inlet pipe 11 is connected to the inlet side of the subcooler 2 so that water taken from various water tanks 13 such as a heat storage tank by a pump 12 is sent into the subcooler 2. It has become. Further, as a heater, for example, a preheater 14 is provided on the upstream side of the pump 12 in the introduction pipe 11.
Is provided, and it is possible to heat the water flowing in the introduction pipe 11 to, for example, 0.5 ° C.

One end of a water injection pipe 21 is connected to the downstream side of the pump 12 in the introduction pipe 11, and the other end is
It is connected to an outer container 22 that covers the outer circumference of the connecting pipe 3 in a watertight manner. Therefore, a part of the water in the introduction pipe 11 bypasses the subcooler 2 through the water injection pipe 21 and is sent into the outer container 22. Therefore, the water supply to the water injection pipe 21 and the water supply to the subcooler 2 are performed by one pump 12.

As shown in FIG. 2, the connecting pipe 3 is divided at right angles to the axial direction so as to create a space d in the outer container 22, and the upstream connecting pipe 3a and the downstream connecting pipe 3b are connected. It is divided into Therefore, when water is injected from the water injection pipe 21 into the outer container 22, the connection pipe 3 is discharged from the gap d.
The water that has entered the inside flows along the flow in the connecting pipe 3 to the downstream side along the wall surface of the downstream connecting pipe 3b, and a liquid film of water injected into the wall surface of the downstream connecting pipe 3b is formed. It is supposed to be done. Since the pressure applied to the water flowing through the water injection pipe 21 by the pump 12 is maintained up to the outer container 22, there is no problem in pushing the water into the connection pipe 3 through the gap d described later.

The ice making device 1 according to the present embodiment has the above-mentioned configuration. Next, an operation example thereof will be explained. For example, when 0 ° C. water is taken from the water tank 13, it is preheated. The temperature is raised to 0.5 ° C. by the vessel 14. This 0.5 ° C. water is cooled in the supercooler 2 to, for example, a supercooled state of −2 ° C., and is sent to the releaser 4 through the connecting pipe 3 as it is, and the releaser 4 releases the supercooled state. As a result, for example, slurry ice at 0 ° C. is produced and continuously discharged to the outside.

On the other hand, the water of 0.5 ° C. branched from the introduction pipe 3 and flowing into the water injection pipe 21 is injected into the outer container 22 and enters the connection pipe 3 from the divided portion of the connection pipe 3, that is, the space d. It enters and flows downstream along the flow of supercooled water. At this time, since the void d extends over the entire circumference, the 0.5 ° C. water flows along the wall surface of the inner wall of the downstream side connecting pipe 3b, and as a result, 0.
A liquid film of water at 5 ° C is formed. The junction between the water injection pipe 21 and the external container 22 (water injection / reception opening for water injection) is set with a predetermined distance from the gap d with its axis displaced.
This is a structure for injecting water uniformly from the entire circumference of the wall surface.

Therefore, even if the supercooling removal performed in the releaser 4 is going to propagate to the upstream side along the wall surface, a liquid film of 0 ° C. or more is formed on the wall surface of the inner wall of the downstream side connecting pipe 3b. Therefore, the propagation to the upstream side is prevented. In addition, even if ice nuclei are present, they do not grow inside the liquid film formed on the wall surface above 0 ° C, and eventually melt or flow to the downstream due to the flow of supercooled water. The phase change does not propagate beyond the outlet of the connecting pipe 3 to the upstream side. Therefore, freezing at the outlet of the connecting pipe 3 and the supercooler 2 is prevented, and stable ice in a slurry state can be continuously produced.

Further, unlike the prior art, it is not necessary to apply special processing such as resin to the surface of the wall surface, and a stable propagation preventing effect can be obtained for a long period of time. Further, in the present embodiment,
Although the water for forming the liquid film is heated to 0.5 ° C. by the preheater 14, the energy required for the heating is extremely small, and the conventional method is to heat the direct connecting pipe or the like to prevent freezing. Compared with, much less energy is needed.

In this embodiment, a part of the water flowing through the introduction pipe 11 is branched and poured into the outer container 22, so that it is necessary to separately secure a water source for pouring water into the outer container 2. There is no.

In the present embodiment, the preheater 14 is installed so as to heat the water flowing in the introduction pipe 11, but the preheating device 14 is individually heated for the water flowing in the water injection pipe 21, For example, an appropriate temperature adjusting device such as a heater in which a sensor and a controller are combined may be provided. This makes it possible to set an appropriate temperature for each water for water injection. In this case, the outlet of the water injection pipe 21 is the introduction pipe 11
It may not be a branched portion of the above, and may be taken out directly from a water source such as a water tank, or the water supply and the external container 22 may be connected via a valve and a temperature adjusting device.

The divided end faces of the connecting pipe 3, that is, the end face of the upstream connecting pipe 3a and the end face of the downstream connecting pipe 3b are preferably shaped as shown in FIG. .

In the example shown in FIG. 3, the inner wall 31 side of the end surface of the upstream side connecting pipe 3a is made to project toward the downstream side, and the outer wall 32 side of the end surface of the downstream side connecting pipe 3b is set to the upstream side. It has a taper shape that is projected toward.

In the example shown in FIG. 4, the inner wall 31 side of the end face of the upstream side connecting pipe 3a has a taper shape protruding toward the downstream side as in the example of FIG. 3, but the end face of the downstream side connecting pipe 3b. The outer wall 32 side is projected toward the upstream side, and the end surface 33 itself of the downstream side connecting pipe 3b is convexly curved toward the upstream side.

In the example shown in FIG. 5, the inner wall 31 side of the end face of the upstream connecting pipe 3a projects more downstream than the outer wall 34 side, and the inner wall 35 side of the end face of the downstream connecting pipe 3b than the outer wall 32 side. A tip 36 of the end face of the upstream connecting pipe 3a, which projects to the upstream side,
The tip end 37 of the end surface of the upstream side connecting pipe 3b has a structure having a surface cut perpendicular to the axial direction.

In the example shown in FIG. 6, the inner wall 31 side of the end face of the upstream connecting pipe 3a is made to project more downstream than the outer wall 34 side,
The inner wall 35 side of the end face of the downstream side connecting pipe 3b is projected more upstream than the outer wall 32 side, and the end face 38 of the upstream side connecting pipe 3a and the end face 39 itself of the downstream side connecting pipe 3b are located outside the connecting pipe 3. The shape is convexly curved toward the end.

The connecting pipe 3 as shown in FIGS. 3 to 6 described above.
If the divided end face shape is adopted, the water that has entered from the gap d flows more suitably along the inner wall 35 of the downstream side connecting pipe 3b, and the liquid due to the water is applied to the surface of the inner wall 35 of the downstream side connecting pipe 3b. It is possible to more suitably form the film. As a result of the experiment conducted by the inventor using the divided end face shapes shown in FIGS. 3 to 6, the embodiment of FIG. 4 showed the best effect. In addition to the above-described embodiment, for example, a plate heat exchanger can be used instead of the shell-and-tube heat exchanger (supercooler). Also, as the outer container 22, in addition to the box shape, an annular one having a larger diameter than the connecting pipe 3 can be used.

[0036]

According to the present invention, in the production of ice by releasing supercooling by a so-called closed system, no special heating energy or special processing on the end surface of the connecting pipe is required, and it is stable for a long period of time. Thus, the phase change can be prevented from propagating from the release device to the connecting pipe. Therefore, it is possible to continuously eliminate the supercooled state of water to make ice, and to perform this stably for a long time.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of a configuration of an ice making device according to an embodiment.

FIG. 2 is a partial cross-sectional side view showing the inside of the connecting pipe in the ice making device according to the embodiment.

FIG. 3 is a side sectional view showing another example of the divided end surface of the connecting pipe.

FIG. 4 is a side sectional view showing another example of the divided end surface of the connecting pipe.

FIG. 5 is a side sectional view showing still another example of the divided end surface of the connecting pipe.

FIG. 6 is a side sectional view showing another example of the divided end surface of the connecting pipe.

[Explanation of symbols]

1 ice production equipment 2 supercooler 3 connecting pipe 3a Upstream connecting pipe 3b Downstream connecting pipe 4 Release device 11 Introduction tube 14 Preheater 21 Water injection pipe 22 External container d void

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takahiko Mikami             1-28-6 Funabashi, Setagaya-ku, Tokyo Bibarch             F Funabashi 105

Claims (11)

[Claims] 1. A method for producing ice by sending water, which has been supercooled by a subcooler, to a closed system subcooler without contacting the atmosphere through the connecting pipe, to produce ice. Is characterized by supplying water at 0 ° C or higher,
Ice making method. 2. The method of producing ice according to claim 1, wherein the water at 0 ° C. or higher is water immediately before entering the subcooler. 3. The ice manufacturing method according to claim 1, wherein the water having a temperature of 0 ° C. or higher is water obtained by heating the water taken from the heat storage tank. 4. A subcooler for bringing water into a supercooled state, a closed system releaser for releasing water in a supercooled state, and a connecting pipe connecting an outlet of the subcooler and an inlet of the releaser. In the ice manufacturing device having: an outer container that watertightly surrounds the outer periphery of the connecting pipe, and a water injection pipe that injects water into the outer container,
The ice making device, wherein the connecting pipe is divided along the entire circumference in the outer container via a gap. 5. The water injection pipe is branched from an introduction pipe connected to the inlet side of the subcooler, bypasses the subcooler, and is connected to the external container. The ice making device according to claim 4, characterized in that: 6. The divided end surface of the connecting pipe is tapered such that the inner wall side of the end surface of the upstream connecting pipe projects toward the downstream side, and the outer wall side of the end surface of the downstream connecting pipe projects toward the upstream side. The ice making device according to claim 4 or 5, wherein the ice making device has a tapered shape. 7. The split end surface of the connecting pipe is tapered such that the inner wall side of the end surface of the upstream connecting pipe projects toward the downstream side, and the outer wall side of the end surface of the downstream connecting pipe projects toward the upstream side. The end face of the downstream side connecting pipe is curved convexly toward the upstream side.
The ice-making device according to 1. 8. The divided end surface of the connecting pipe is such that the inner wall side of the end surface of the upstream connecting pipe projects more downstream than the outer wall side and the inner wall side of the end surface of the downstream connecting pipe projects more upstream than the outer wall side. ，
The ice making device according to claim 4 or 5, wherein an end of each end face on the inner wall side has a face perpendicular to the axial direction. 9. The divided end surface of the connecting pipe is such that the inner wall side of the end surface of the upstream connecting pipe projects more downstream than the outer wall side and the inner wall side of the end surface of the downstream connecting pipe projects more upstream than the outer wall side. ，
The ice making device according to claim 4 or 5, wherein each end surface itself is convexly curved toward the outside of the connecting pipe. 10. The heater according to claim 5, further comprising a heater for heating water flowing in the introduction pipe, which is upstream of the connection portion of the water injection pipe in the introduction pipe. The ice making device described in Crab. 11. The temperature control device for controlling the temperature of water flowing through the water injection pipe, according to claim 4,
The ice manufacturing device according to any one of 5, 6, 7, 8 and 9.