JP6910215B2 - Slurry ice making equipment and method - Google Patents

Description

The present invention relates to a slurry ice production apparatus and method for producing slurry ice in which a liquid to be frozen is frozen in a sherbet shape.

In recent years, several methods for producing slurry ice have been shown.
For example, in Patent Document 1, a liquid and a low-temperature refrigerant are heat-exchanged through a metal pipe wall of a double pipe, and ice adhering to the pipe wall is scraped off by a scraper (or a plurality of expressions such as a slurry). This discloses a technique for producing slurry ice.
Further, in Patent Document 2, a cooling medium flow path is provided in which a cooling medium is sealed in a container and a cooling medium is circulated, and a plurality of small objects are sealed in the cooling medium to allow the cooling medium to flow. A method of scraping ice adhering to the surface of the cooling medium flow path by causing the small object to collide with the surface of the cooling medium flow path by stirring is disclosed to generate slurry ice.
Further, Patent Document 3 discloses an ice making method in which a liquid in a vessel is supercooled and released to produce slurry ice (sherbet-like ice water).
Further, in Patent Document 4, after supercooling cold water with a supercooler, ice is generated by injecting it onto the liquid surface of the cold water stored in the heat storage tank, and the cold water at the lower part of the heat storage tank is airlifted upward. Disclosed is a technique for producing slurry ice (dynamic ice) and storing heat by moving the ice generated on the liquid surface downward by leading to.
The techniques disclosed in Patent Documents 1 to 4 are for making ice using a Freon refrigerator, but a technique for making ice using a low-temperature liquefied gas is also shown.
For example, Patent Document 5 discloses a technique of continuously freezing an object to be frozen such as droplets into a cryogenic liquefied gas flowing through a flow path while circulating using an air lift pump.

Japanese Unexamined Patent Publication No. 2006-266639 Japanese Unexamined Patent Publication No. 10-160208 Japanese Unexamined Patent Publication No. 5-172444 Japanese Unexamined Patent Publication No. 10-148367 Japanese Unexamined Patent Publication No. 7-8240

However, as described above, the techniques disclosed in Patent Documents 1 to 4 are ice making and heat storage techniques using a Freon refrigerator, mainly for large-scale equipment, and are sufficient for long-term operation. While ensuring economic efficiency, as a simple ice making method in a short period of time, the equipment cost burden was excessive and it was not economical, and it was not suitable for small-quantity production.
Further, the technique disclosed in Patent Document 5 circulates a cryogenic liquefied gas by an air lift pump, so that it can be operated economically without requiring power such as electric power, but it is a slurry ice frozen in a sherbet shape. Is not manufactured.

Therefore, the present inventors have proposed a method for producing slurry ice using a low-temperature liquefied gas (Japanese Patent Application No. 2016-164613). In this method, a low-temperature liquefied gas is injected onto the liquid surface from above the liquid surface of a liquid to be frozen (for example, water) stored in a container, and the injected liquefied gas floats and sinks and shakes in the liquid to be frozen. The liquid to be frozen is frozen in a slurry state (sherbet shape) by moving, and it is suitable for using a liquefied gas having a specific gravity larger than that of the liquid to be frozen.
Therefore, a slurry ice production apparatus and method capable of efficiently and stably producing slurry ice with a simple facility even when a liquefied gas (for example, liquid nitrogen) having a specific gravity smaller than that of the liquid to be frozen is used is desired. It was rare.

The present invention has been made to solve the above-mentioned problems, and is a slurry ice production apparatus capable of easily producing slurry ice in which a liquid to be frozen is frozen in a sherbet shape at a low equipment cost. The purpose is to provide a method.

(1) The slurry ice producing apparatus according to the present invention is for producing slurry ice by freezing the liquid to be frozen in a sherbet shape, and has a storage tank for storing the liquid to be frozen which is a raw material of the slurry ice. A low-temperature liquefied gas nozzle that is disposed in the storage tank and discharges a low-temperature liquefied gas having a specific gravity smaller than that of the liquid to be frozen, and a liquid to be frozen that surrounds the low-temperature liquefied gas nozzle and is stored in the storage tank. A tubular body that is arranged in the storage tank so as to project above the liquid surface and has an introduction port for introducing the liquid to be frozen at the lower part and an opening at the upper part, respectively. An air lift gas supply unit that supplies air lift gas that airlifts the slurry ice generated in the tubular body and the liquid to be frozen, and the slurry that is provided near the opening of the tubular body and is taken out from the opening. It is characterized by including a solid-liquid separation unit for separating ice and the liquid to be frozen and taking out slurry ice.

(2) The above-mentioned item (1) is characterized in that a nozzle heating means for preventing freezing is provided at the tip of the cryogenic liquefied gas nozzle.

(3) The above-mentioned item (1) or (2) is characterized in that a tube wall heating means for heating the inner wall of the tubular body is provided.

(4) In any of the above (1) to (3), the low temperature liquefied gas supply amount adjusting means for adjusting the supply amount of the low temperature liquefied gas supplied to the low temperature liquefied gas nozzle, and the air lift gas supply unit. It is characterized by being provided with an air lift gas supply amount adjusting means for adjusting the supply amount of the air lift gas supplied to the vehicle.

(5) In the slurry ice production method according to the present invention, the slurry ice to be frozen is frozen in a sherbet shape using the slurry ice production apparatus according to any one of (1) to (4) above to produce slurry ice. In the liquid to be frozen introduced into the tubular body, a low-temperature liquefied gas having a specific gravity smaller than that of the frozen liquid is discharged and air lift gas is supplied to form a slurry ice produced in the tubular body. It is characterized in that the liquid to be frozen is air-lifted, the slurry ice taken out from the opening of the tubular body and the liquid to be frozen are separated by the solid-liquid separation part, and the slurry ice is taken out. ..

(6) In the one described in (5) above, the cryogenic liquefied gas is liquid nitrogen, and the air lift gas is gaseous nitrogen.

In the present invention, the liquid to be frozen is frozen in a sherbet shape to produce slurry ice, which is disposed in a storage tank for storing the liquid to be frozen, which is a raw material for the slurry ice, and a storage tank. A low-temperature liquefied gas nozzle that discharges a low-temperature liquefied gas having a specific gravity smaller than that of the liquid to be frozen and a low-temperature liquefied gas nozzle that surround the low-temperature liquefied gas nozzle and project above the liquid level of the liquid to be frozen stored in the storage tank. A tubular body having an introduction port for introducing the liquid to be frozen at the lower part and an opening at the upper part, and slurry ice generated in the tubular body. The air lift gas supply unit that supplies the air lift gas that airlifts the liquid to be frozen and the slurry ice that is provided in the vicinity of the opening of the tubular body and is taken out from the opening and the liquid to be frozen are separated. Since the solid-liquid separation unit for taking out the slurry ice is provided, the slurry ice can be produced inexpensively and easily with simple equipment.

It is a schematic diagram for demonstrating the slurry ice production apparatus and method which concerns on this Embodiment. It is a figure for demonstrating another aspect of the slurry ice production apparatus and method which concerns on this embodiment. It is sectional drawing for _{demonstrating the LN 2} nozzle used in another aspect of the slurry ice production apparatus and method which concerns on this embodiment.

The slurry ice producing apparatus 1 according to the embodiment of the present invention is for producing slurry ice by freezing the liquid to be frozen in a sherbet shape, and as shown in FIG. 1, the water tank 3 and the LN ₂ nozzle 5 The air lift pipe 7, the GN ₂ supply unit 9, and the solid-liquid separation unit 11 are provided.
Hereinafter, each component of the slurry ice production apparatus 1 will be described. In this embodiment, a case where water is used as the liquid to be frozen, liquid nitrogen (LN ₂ ) is used as the cryogenic liquefied gas, and gaseous nitrogen (GN ₂ ) is used as the air lift gas will be described. The water used as the liquid to be frozen may be either fresh water or seawater.

<Aquarium>
The water tank 3 is a storage tank for storing water as a raw material for slurry ice.
As will be described later, the water tank 3 shown in FIG. 1 is provided with water temperature adjusting means 13 for adjusting the water temperature in the water tank 3.

<LN ₂ nozzle>
The LN ₂ nozzle 5 is arranged in the water tank 3 _{to discharge LN 2} having a specific density smaller than that of water. In FIG. 1, the front end side is inserted into the water tank 3 and the rear end side supplies _{LN 2.} It communicates with the liquid phase side in the tank 15 _{via the LN 2} supply flow path 17.

The LN ₂ nozzle 5 may be arranged so that the tip of the LN 2 nozzle 5 is located in the middle of the water depth (hs in FIG. 1) where a sufficient contact time with water can be obtained. Further, as shown in FIG. 1, the LN ₂ nozzle 5 is provided with a nozzle heating means such as a heater 19 at the tip in order to prevent the tip submerged in the water tank 3 from being frozen and blocked by water. However, it is desirable to suppress the growth of ice. In this case, it is sufficient that the temperature set by the heater 19 is about 5 ° C. or higher.

<Air lift pipe>
The air lift pipe 7 corresponds to the tubular body of the present invention _{, and is arranged in the water tank 3 so as to surround the LN 2} nozzle 5 and project upward from the liquid level of the water stored in the water tank 3. It is provided and has an introduction port 7a for introducing water in the lower part and an opening 7b in the upper part.

The introduction port 7a is located below the water surface of the water tank 3 in order to introduce water supplied from the outside (water tank 3) into the air lift pipe 7. Further, it is desirable that the introduction port 7a has _{an appropriate opening size in order to prevent the GN 2 supplied by the GN 2} supply unit 9 from going out to the liquid layer outside the air lift pipe 7.

In air-lift pipe 7, as shown in FIG. 1, by LN ₂ discharged from LN ₂ nozzle 5 becomes a plurality of substantially spherical, floats while swinging the water is vaporized by the heat of the water Water freezes like sherbet to produce slurry ice. Then, in order to take out the slurry ice generated in the air lift pipe 7, the air lift pipe 7 is arranged so that the opening 7b is located above the liquid level in the water tank 3. In this case, the height from the water surface of the water tank 3 to the opening 7b (ht in FIG. 1) is the lift in the slurry ice manufacturing apparatus 1.

_{Similar to the LN 2} nozzle 5, the air lift pipe 7 is equipped with a pipe wall heating means such as a heater 21 in order to prevent water from freezing and blocking on the inner wall, and ice adheres to and grows on the inner wall of the air lift pipe 7. It is desirable to prevent this. In this case, it is sufficient that the temperature set by the heater 21 is about 5 ° C. or higher.

<GN ₂ supply unit>
The GN _{2 supply unit 9 is an air lift gas supply unit that supplies GN 2} that airlifts the slurry ice generated in the air lift pipe 7 and the water introduced in the air lift pipe 7, and is installed in the lower part of the air lift pipe 7. Has been done. As shown in FIG. 1, the _{GN 2} supply unit 9 communicates with the gas phase side in the _{LN 2 supply tank 15 via the GN 2} supply flow path 23, and gas nitrogen (GN ₂ ) _{in the LN 2 supply tank 15.} Is supplied as air lift gas.

The GN ₂ supply unit 9 may _{be installed at a position where the mixture of water and slurry ice after the contact between LN 2} and water is pushed up from below. In FIG. 1, the bottom layer portion (bottom surface) of the water tank 3 is used. ). In this case, the water depth hs is the height from the bottom surface of the water tank 3 in which _{the GN 2 supply unit 9 is installed to the water surface, as shown in FIG.}

However, the GN ₂ supply unit 9 is not limited to the one provided in the lowermost layer portion of the water tank 3, and is _{below the LN 2 discharge port of the LN 2} nozzle 5 and above the introduction port 7a of the air lift pipe 7. It may be provided so as to be located at. In this case, depth hs is a height from the positions of the GN ₂ supply unit 9 is a position where GN ₂ comes into contact with water and start to water.

<Solid liquid separation part>
The solid-liquid separation unit 11 is provided in the vicinity of the opening 7b of the air lift pipe 7, and separates and takes out the slurry ice from a mixture of slurry ice and water that is air-lifted in the air lift pipe 7 and discharged from the opening 7b. For the solid-liquid separation unit 11, a wire mesh, punching metal, or the like, which is a solid-liquid separation facility, can be used.

In FIG. 1, the solid-liquid separating portion 11 is installed in the opening 7b of the air lift pipe 7 so as to incline downward. As a result, the mixture of slurry ice and water discharged from the opening 7b of the air lift pipe 7 is separated into slurry ice and water while sliding down on the solid-liquid separation section 11, and the separated slurry ice is placed in the container 25. Can be taken out. On the other hand, the surplus water separated by the solid-liquid separation unit 11 can be dropped from the solid-liquid separation unit 11 into the water tank 3 and introduced into the air lift pipe 7 again.

As described above, according to the slurry ice producing apparatus 1 according to the present embodiment, in a system in which the specific gravity of the liquid to be frozen is heavier than that of the low temperature liquefied gas, LN ₂ is discharged into the air lift pipe 7 to generate slurry ice. At the same time, GN ₂ is supplied into the air lift pipe 7, the mixture of slurry ice and water is air-lifted and discharged from the opening 7b, and the slurry ice is separated and taken out from the mixture, so that it is inexpensive and easy with simple equipment. Slurry ice can be continuously produced for a certain period of time. Further, according to the slurry ice production apparatus 1, _{the range of contact frequency and contact time between LN 2} and water suitable for the slurry ice production conditions is wide, and a small amount of slurry ice can be easily produced even on a small scale. Can be done.

As shown in FIG. 1, the slurry ice producing apparatus 1 according to the present embodiment is further provided with a water replenishment unit 27 and a water temperature adjusting means 13.

The water supply unit 27 replenishes the water tank 3 with water, and by reinforcing the water corresponding to the amount taken out as slurry ice, the liquid level position in the water tank 3, that is, the lift (ht in FIG. 1). ) Can be kept constant to generate and remove slurry ice.

As shown in FIG. 1, the water temperature adjusting means 13 includes a heater 29, a water temperature detecting end 31, and a temperature adjusting mechanism 33, and the temperature is based on the water temperature detected by the water temperature detecting end 31. The output of the heater 29 is controlled by the adjusting mechanism 33 to constantly adjust the water temperature in the water tank 3.

As described above, the slurry ice production apparatus 1 separates the excess water that has not become slurry ice by the solid-liquid separation unit 11 and drops it into the water tank 3 for circulation, but the separated water is circulated. As it is used, the temperature of the water in the water tank 3 may drop too much and all of it may become ice. Therefore, by adjusting the water temperature in the water tank 3 by the water temperature adjusting means 13, it is possible to prevent the water temperature in the water tank 3 from dropping too much even when it is used for a relatively long time, and it is continuous for a long time. The slurry ice can be produced and taken out.

Further, the slurry ice manufacturing apparatus 1 according to the present embodiment controls a low temperature liquefied gas supply amount adjusting means (not shown) for controlling the amount of low temperature liquefied gas supplied to the air lift pipe 7 and an air lift gas amount to be supplied to the air lift pipe 7. It is preferable to provide an air lift gas supply amount adjusting means (not shown).

In the slurry ice production apparatus 1 shown in FIG. 1, the low temperature liquefied gas supply amount adjusting means is provided, for example, in _{the LN 2} supply flow path 17 that communicates the liquid phase side of the _{LN 2 supply tank 15 with the LN 2} nozzle 5. Further, the air lift gas supply amount adjusting means can be provided, for example, in _{the GN 2} supply flow path 23 that communicates the gas phase side of the _{LN 2 supply tank 15 with the GN 2} supply unit 9.

_{Then, the amount of LN 2 and the} amount of GN ₂ supplied into the air lift pipe 7 installed in the water tank 3 are adjusted by the low temperature liquefied gas supply amount adjusting means and the air lift gas supply amount adjusting means, and the lift height ( _{By adjusting the ratio of the amount of LN 2 and the} amount of GN ₂ according to the lift), it can be operated continuously for a certain period of time.

As described above, in the slurry ice production apparatus 1 provided with the water temperature adjusting means 13, the low temperature liquefied gas supply amount adjusting means and the air lift gas supply amount adjusting means, the water temperature adjusting means 13 effectively acts to the water tank 3 By adjusting the water temperature inside to be constant, it is possible to control the lift in the air lift pipe 7 (ht in FIG. 1), the amount of _{GN 2 and LN 2} supplied to the air lift pipe 7, and their ratios. , It is possible to bring the slurry ice production conditions closer to the optimum values while operating the slurry ice production apparatus 1.

However, the slurry ice producing apparatus 1 shown in FIG. 1 supplies the amount of _{LN 2} to the air lift pipe 7 when the initial water temperature of the water stored in the water tank 3 is high or when the initial temperature of LN ₂ or GN _{2 is high.} In addition to adjusting the amount of GN and GN _2, it may be necessary to gradually change the lift to the optimum height.

As described above, _{the optimum amount of LN 2} and GN ₂ supplied to the air lift pipe 7 can be easily adjusted by the low temperature liquefied gas supply amount adjusting means and the air lift gas supply amount adjusting means connected to the _{LN 2 supply tank 15.} It is possible to do.

As the low-temperature liquefied gas supply amount adjusting means and the air lift gas supply amount adjusting means, a valve such as a flow rate adjusting valve that can variably adjust the throttle can be used, but upstream (LN ₂ supply tank 15) and downstream (water tank 3). If the pressure condition of the above is approximately constant, it is also possible to use a diaphragm (orifice) having a constant hole diameter. When an orifice or the like is used, the conditions (suitable hole diameter, etc.) can be determined by testing in advance.

_{Since a part of LN 2} is vaporized in the LN ₂ supply tank 15 due to invading heat such as outside temperature, the inside of the appropriately sealed LN ₂ supply tank 15 is vaporized by vaporization. Since both the phase (GN ₂ ) and the liquid phase (LN ₂ ) have pressure, both GN ₂ and LN ₂ can be supplied to the water tank 3 by this self-pressure. _{However, if LN 2} and GN ₂ are supplied by a mere pressure difference, there is a risk of excessive supply, depending on the piping resistance. Therefore, the above-mentioned cryogenic gas supply amount adjusting means and air lift gas supply amount adjusting means should be provided. Is preferable.

On the other hand, regarding the lift, when the air lift pipe 7 is fixedly installed on the bottom surface of the water tank 3 as shown in FIG. 1, it is difficult to control the height to the optimum height during the operation of the slurry ice production apparatus 1. be.

Therefore, as another aspect of the slurry ice producing apparatus according to the present invention, the water tank 3 specially designed as shown in FIG. 1 is not used, but as shown in FIG. 2, the bottomed tubular air lift pipe 43 is used. It is composed of a flat plate-shaped solid-liquid separation wire net 45 as a solid-liquid separation part attached to the upper end opening 43a of the air lift pipe 43, an LN ₂ nozzle 47 that _{can be inserted into the air lift pipe 43, and a GN 2} introduction pipe 49. The slurry ice production unit 41 may be arranged in a general-purpose water tank.

The air lift pipe 43 is similar to that of FIG. 1 in that it has an upper end opening 43a at the upper portion and an introduction port 43b at the lower portion, but is different from that of FIG. 1 in that it has a bottom. By making it bottomed, it can be arranged in a general-purpose water tank and supplied so as to blow out _{GN 2} downward from the _{GN 2 introduction pipe 49.}

The solid-liquid separation wire mesh 45 is fixed to the air lift pipe 43 by welding or the like so as to surround the periphery of the upper end opening 43 a of the air lift pipe 43 and to project in an inclined state. However, even if the solid-liquid separation wire net 45 is not fixed to the air lift pipe 43, for example, the solid-liquid separation wire net 45 is provided with an opening into which the air lift pipe 43 can be inserted, and the upper end opening 43 a of the air lift pipe 43 is provided with a flange portion. Etc. may be provided so that the air lift pipe 43 inserted into the opening is supported by the opening edge of the solid-liquid separation wire net 45.

By attaching the solid-liquid separation wire mesh 45 to the upper end opening 43a of the air lift pipe 43 as described above, the solid-liquid separation wire mesh 45 is placed on the edge of the general-purpose water tank, and the air lift pipe 43 is placed on the edge of the general-purpose water tank to be frozen. It can be supported in a state of being immersed in it.

The LN _{2 nozzle 47 is a low temperature liquefied gas nozzle that discharges LN 2} as a low temperature liquefied gas into the air lift pipe 43, and has a vacuum heat insulating pipe portion 51 having a vacuum heat insulating layer 51a formed inside as shown in FIG. Then, inside the vacuum insulation pipe portion 51, an _{introduction flow path 53 in which LN 2} flows from top to bottom and a discharge in _{which LN 2} flows upward through communication with the introduction flow path 53 at the lower end of the introduction flow path 53. The flow path 55 is formed. _{An LN 2} outlet 55a is provided at the upper end of the discharge flow path 55, and the upper end of the introduction flow path 53 communicates with the introduction pipe 57 extending further upward from the vacuum insulation pipe portion 51. Further, the upper end of the inlet tube 57, the connecting portion 57a for connecting the supplying LN ₂ LN ₂ supply pipe (not shown) is provided.
The LN ₂ outlet 55a and the introduction pipe 57 are provided with a heater 59 for heating them.

The GN ₂ introduction pipe 49 is an air _{lift gas supply unit that supplies GN 2} as air lift gas into the air lift pipe 43, and is inserted into the air lift pipe 43 and adjacent to the _{LN 2 nozzle 47 as shown in FIG.} It is arranged so that the GN ₂ inlet 49a is provided at the upper end and the GN ₂ outlet 49b is provided at the lower end.
In order to prevent the flow path in the air lift pipe 43 from being blocked due to freezing, the GN ₂ introduction pipe 49 is provided with a heating means such as a heater 61 at a portion above the vicinity _{of the adjacent LN 2 outlet 55a.} ing.
_{Although the GN 2} outlet 49b is located below the introduction port 43b of the air lift pipe 43 in FIG. 2, it may be provided above the introduction port 43b.

When the slurry ice production unit 41 having each of the above configurations is arranged in the general-purpose water tank, the lower part of the air lift pipe 43 is submerged in the water stored in the general-purpose water tank to introduce water from the introduction port 43b and the connecting portion. The upper part of the air lift pipe 43 is installed so as to project upward from the water surface so that 57a, the GN _{2 inlet 49a and the solid-liquid separation wire mesh 45 are located above the water surface.} As a result, even while the apparatus is in operation, the height (lift) from the water surface to the upper end opening 43a can be easily changed by changing the position in the height direction of the slurry ice manufacturing unit 41. It can be adjusted to the optimum lift.

When the slurry ice production unit 41 is arranged in a general-purpose water tank _{, σ = hs, where the height from the water surface to the upper end opening 43a is the lift ht and the height from the GN 2} outlet 49b to the water surface is the water depth hs. The larger the value of σ represented by / (hs + ht), the higher the lift amount and lift pressure, but it may be difficult to increase the water depth hs with a simple facility such as the slurry ice production unit 41. In addition, if the water depth hs is deep, the contact time between the low-temperature liquefied gas and water becomes long and the amount of slurry ice ice production increases, but it is expected that there is a limit that lift-up cannot be performed no matter how much the _{GN 2 supply amount is increased.} .. In such a case, the optimum _{amount of GN 2} for the water depth hs may be found at the time of trial run adjustment or the like, and the optimum _{amount of GN 2} may be supplied to operate the slurry ice production unit 41.

Next, the slurry ice production method according to the present invention will be described.
The slurry ice production method according to the present embodiment is to produce slurry ice by freezing the liquid to be frozen in a sherbet shape using the slurry ice production apparatus 1 shown in FIG. Hereinafter, the slurry ice production method according to the present embodiment will be described in detail together with the operation of the slurry ice production apparatus 1 shown in FIG.

_{First, liquid nitrogen (LN 2} ) having a specific gravity smaller than that of water is discharged as a liquid to be frozen into the water introduced into the air lift pipe 7, and _{gaseous nitrogen (GN 2} ) is supplied as an air lift gas. _{LN 2} is discharged into the air lift pipe 7 to generate slurry ice, and the generated slurry ice and water are air-lifted and discharged from the opening 7b at the upper part of the air lift pipe 7. Then, the slurry ice and water taken out are separated by the solid-liquid separation unit 11.

The separated slurry ice is slid down on the solid-liquid separation portion 11 provided on an inclined surface and taken out to the container 25. On the other hand, the water separated by the solid-liquid separation unit 11 is dropped into the water tank 3 and introduced into the air lift pipe 7 again from the introduction port 7a at the lower part of the air lift pipe 7. Further, water corresponding to the amount produced as slurry ice may be supplied to the water tank 3 as make-up water from the water supply unit 27.

As described above, according to the slurry ice production method according to the present embodiment, slurry ice can be produced inexpensively and easily with simple equipment, and the produced slurry ice can be easily taken out, and adjustment work and the like can be performed. Slurry ice can be continuously produced for a certain period of time without it.
Further, the slurry ice production method according to the present invention has a wide range of contact frequency and contact time between _{LN 2} and water suitable for the slurry ice production conditions, and by adjusting the amount of _{LN 2 and the} amount of GN _{2 to be supplied.} Optimal conditions can be set for the production of slurry ice.
Further, in the slurry ice production method according to the present invention, the lift height can be adjusted even during the production of slurry ice by using a unitized product such as the slurry ice production unit 41 shown in FIG. The conditions can be further optimized for producing slurry ice.

In the above description of the slurry ice production apparatus and method according to the present invention, water was used as the liquid to be frozen and liquid nitrogen was used as the low temperature liquefied gas. The low-temperature liquefied gas may have a specific gravity smaller than that of the liquid to be frozen, and may be appropriately selected depending on the type of the liquid to be frozen.

_{Further, in the above description, gaseous nitrogen (GN 2} ) vaporized from liquid nitrogen, which is a low-temperature liquefied gas, is used as the air lift gas, but the gas type of the air lift gas is not limited to this, and low-temperature liquefaction is used. A gas type different from that of the gas may be used. However, it is preferable to use the gas vaporized from the low-temperature liquefied gas as the air lift gas because it is not necessary to separately prepare the air lift gas.

A specific experiment was conducted to confirm the action and effect of the slurry ice production apparatus and method according to the present invention, and the results will be described below.

In the experiment, the slurry ice production unit 41 shown in FIG. 2 was installed in a general-purpose water tank, and was stored in the general-purpose water tank using _{liquid nitrogen (LN 2 ) as a cryogenic liquefied gas and gaseous nitrogen (GN 2} ) as an air lift gas. The water was frozen in a sherbet shape to produce slurry ice. Then, the amount of slurry ice produced when the _{lift, the amount of LN 2 and the} amount of GN ₂ , which are the conditions for producing slurry ice, were changed was measured. Here, the slurry ice production unit 41 conducted an experiment by changing the water depth (hs + ht) in the air lift pipe 43 while keeping the height from the water surface to the opening 43b constant (ht = 0.3 m). .. Therefore, in this embodiment, two types of slurry ice production units 41 having different total lengths of the air lift pipe 43 are used. In this case, depth hs is the height from the position (GN ₂ outlets 49b) which GN ₂ comes into contact with water and start to water.
Table 1 shows the slurry ice production conditions and the experimental results of the slurry ice production amount.

In Table 1, the amount of slurry ice produced is the amount of slurry ice obtained by separating excess water with a solid-liquid separation wire mesh 45.
Further, in Table 1, Condition 1, Condition 2, Condition 4 and Condition 5 are _{cases where LN 2} and GN ₂ are supplied to the air lift pipe 43, and are within the scope of the present invention. Conditions 4 and 5 change only the water depth hs by changing the water level of the water stored in the general-purpose water tank.
On the other hand, the condition 3 is that _{only LN 2} is supplied to the air lift pipe 43 without supplying _{GN 2} , which is outside the scope of the present invention.

From Table 1, under conditions 1, 2, 2, 4 and 5, which are within the scope of the present invention, the slurry ice produced in the air lift pipe 43 could be taken out, whereas it was outside the scope of the present invention. Under certain condition 3, the slurry ice could not be taken out.
The reason why the slurry ice could not be taken out under the condition 3 is that the slurry ice generated in the air lift pipe 43 could not be pushed up to the opening 43b only by the gas vaporized by _{LN 2 in the air lift pipe 43.} It was a slurry.

Next, the conditions 1, condition 2, condition 4 and condition 5 in which the GN ₂ amount and the LN _{2 amount are changed are examined.
In condition 1, the supply ratio of GN 2} amount and LN ₂ amount was close to the optimum condition at a lift of 1.3 m, and the slurry ice production amount was 1.1 kg / min, and the expected amount of slurry ice could be produced. ..

Condition 2 has the same lift as Condition 1, but _{because the amount of LN 2} is small, sufficient cooling time and contact frequency for freezing water cannot be obtained, and the amount of slurry ice produced is 0.4 kg / min. The result was less than that of condition 1.

Condition 4 has a smaller water depth hs than conditions 1 and 2, _{and the contact time and cooling time between LN 2} and water are insufficient and the heat exchange time is shortened, which makes it difficult to form slurry ice. , The amount of slurry ice produced was 0.2 kg / min, which was less than that of Condition 2.

Condition 5 is similar to Condition 4 in that the water depth hs is smaller than that of Condition 1 and Condition 2, and the amount of _{LN 2 and GN 2} is smaller than that of Condition 4. Therefore, slurry ice production is produced. The amount was 0.1 kg / min, which was a further decrease from Condition 4.

As described above, according to the slurry ice producing apparatus and method according to the present invention, the slurry ice can be easily produced and taken out, and further, the lift height, the _{amount of LN 2} for freezing the liquid to be frozen, and the amount of _{GN 2} which is an air lift gas. It was confirmed that the optimum conditions for producing slurry ice can be set by changing the supply ratio of these products.

1 Slurry ice production equipment 3 Water tank 5 LN ₂ Nozzle 7 Air lift pipe 7a Introductory port 7b Opening 9 GN ₂ Supply part 11 Solid-liquid separation part 13 Water temperature control means 15 LN ₂ Supply tank 17 LN ₂ Supply flow path 19 Heater 21 Heater 23 GN ₂ Supply flow path 25 Container 27 Water supply unit 29 Heater 31 Water temperature detection end 33 Temperature control mechanism 41 Slurry ice production unit 43 Air lift pipe 43a Upper end opening 43b Introduction port 45 Solid-liquid separation wire net 47 LN ₂ nozzle 49 GN ₂ Introduction Pipe 49a GN ₂ inlet 49b GN ₂ outlet 51 Vacuum insulation pipe part 51a Vacuum insulation layer 53 Introduction flow path 55 Discharge flow path 55a LN ₂ outlet 57 Introduction pipe 57a Connection part 59 Heater 61 Heater

Claims (6)

A slurry ice production device that produces slurry ice by freezing the liquid to be frozen into a sherbet shape.
A storage tank for storing the liquid to be frozen, which is a raw material for the slurry ice,
A cryogenic liquefied gas nozzle disposed in the storage tank and discharging a cryogenic liquefied gas having a specific density smaller than that of the liquid to be frozen.
It is arranged in the storage tank so as to surround the cryogenic gas nozzle and project above the liquid level of the liquid to be frozen stored in the storage tank, and the liquid to be frozen is introduced in the lower part. An air lift pipe having an introduction port for the purpose and an opening at the top, respectively.
And air lift gas supply unit for supplying air lift gas for the air lift the object to be frozen liquid slurry ice generated in the air-lift inner pipe,
It is characterized by being provided in the vicinity of the opening of the air lift pipe and provided with a solid-liquid separating portion for separating the slurry ice taken out from the opening and the liquid to be frozen and taking out the slurry ice. Slurry ice making equipment. The slurry ice production apparatus according to claim 1, wherein a nozzle heating means for preventing freezing is provided at the tip of the low-temperature liquefied gas nozzle. The slurry ice producing apparatus according to claim 1 or 2, wherein the tube wall heating means for heating the inner wall of the air lift tube is provided. It is provided with a low temperature liquefied gas supply amount adjusting means for adjusting the supply amount of the low temperature liquefied gas supplied to the low temperature liquefied gas nozzle and an air lift gas supply amount adjusting means for adjusting the supply amount of the air lift gas supplied to the air lift gas supply unit. The slurry ice producing apparatus according to any one of claims 1 to 3, wherein the slurry ice is produced. A slurry ice production method for producing slurry ice by freezing the liquid to be frozen in a sherbet shape using the slurry ice production apparatus according to any one of claims 1 to 4.
To be frozen in liquid introduced into the air-lift pipe, airlift air lift gas supply, said to be frozen liquid and the resulting slurry ice in the airlift the tube while discharging a small low-temperature liquefied gas specific gravity than the frozen liquid Let me
A method for producing slurry ice, which comprises separating the slurry ice taken out from the opening of the air lift pipe and the liquid to be frozen by the solid-liquid separating part, and taking out the slurry ice. The slurry ice production method according to claim 5, wherein the cryogenic liquefied gas is liquid nitrogen, and the air lift gas is gaseous nitrogen.

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