JP5656037B1 - Interfacial forward freeze concentration system - Google Patents

Abstract

An interface forward freezing and concentrating system capable of easily cutting and transporting ice crystals and being excellent in preservation of a solute in a melt. An interface forward freeze concentration system according to the present invention includes an ice crystal generation unit that generates a hollow bar-like ice crystal in a vertical pipe by circulating the solution in the vertical pipe while cooling the outside of the vertical pipe with a refrigerant. An open / close valve that opens and closes the lower opening of the vertical pipe, and is disposed below the vertical pipe. The ice crystal taken out by being naturally dropped from the vertical pipe by opening the open / close valve is placed on the transfer surface and transferred. An ice crystal crushing conveyor and an ice crystal melting part for partially melting the conveyed ice crystal to obtain a melt having a desired concentration are provided. In addition, it is provided with convex portions arranged at predetermined intervals on the transport surface, and by hooking the lower end of the ice crystal that naturally dropped from the lower opening to the convex portion that is running, the ice crystal is placed near the lower opening. Cut sequentially. [Selection] Figure 3

Description

  The present invention relates to an interfacial forward freeze concentration system that generates a concentrated solution by cooling and freezing various solutions such as aqueous solution, fruit juice, and sake and removing ice crystals.

Conventionally, concentrated concentrates of raw materials have been used in various fields such as foods and pharmaceuticals, and freeze concentration methods are known as one of the methods for producing concentrated liquids.
Compared with evaporative concentration and membrane concentration methods, freeze concentration method enables high-quality concentration of the raw material solution, and it is also excellent as a crystallization method for thermally unstable solutes due to its low-temperature concentration. ing.

Among the freeze concentration methods, the interfacial forward freeze concentration method generates and grows ice crystals from the cooling surface that comes into contact with a sample solution such as fruit, that is, the interface between the unfrozen solution phase and the ice phase is the unfrozen solution phase. This is a method of freezing and concentrating by making a single ice crystal by moving it forward (opposite to the heat transfer direction). Control of the ice crystal growth rate and stirring of the interface between the frozen phase and the liquid phase are important. is there.
Since this method produces one large ice crystal, it has an advantage that solid-liquid separation is extremely easy and the system can be simplified as compared with the conventional freeze concentration method (suspension crystal method). In addition, solutes (nutrient components and flavor components) are incorporated into ice crystals in a non-selective manner. Therefore, there is an advantage that the balance of the solute components contained in the concentrated liquid is almost the same as that before the concentration, the solute has excellent storability, and the flavor can be enhanced by preventing deterioration of the quality of fruit juice and the like. Such non-selective uptake of solute components into ice crystals is presumed to be due to a non-equilibrium uptake mechanism of solutes into the voids of the ice crystal structure.

As an interfacial forward freeze concentration apparatus, for example, Patent Document 1 includes a plurality of double cylindrical tubes each composed of an upright outer tube and an inner tube inserted into the outer tube. A technique for growing a hollow ice crystal on the inner wall surface of the inner tube by circulating a refrigerant in the outer tube while circulating the water is disclosed. In this device, a ball valve is connected to the lower part of each double cylindrical tube, and the control device opens the ball valve so that hollow ice crystals are naturally dropped from the inner tube by its own weight, and then the ball is By closing the valve, the ice crystals are sheared to an appropriate length. The sheared ice crystals are collected by a receiver disposed below the ball valve (see FIGS. 1 to 4 of Patent Document 1), and further crushed with a rotating blade of a crusher (see FIG. 5). It has a mechanism to transport by.
For example, Patent Document 2 discloses that a high-concentration molten solution is first recovered by sending air to the recovered hollow ice crystals with a blower and melted until a low-concentration molten solution is obtained. Techniques relating to partial melting that are recovered in stages are disclosed.

JP 2005-144202 A JP 2002-153859 A

However, the conventional techniques as disclosed in the above patent documents have the following problems.
That is, in the technique of Patent Document 1, since the ice crystal is cut by a ball valve, the apparatus configuration becomes complicated and the manufacturing cost increases, and the place where the ice crystal collected by the receiver is placed on the carriage and the melting work is performed. There is a problem that it is difficult to automate the apparatus in actual production because it is moved. In addition, although the hardness of ice crystals varies depending on the concentration of the solution and the type / component ratio of the solute, if the ice crystals are crushed with a crusher, the size of the ice pieces will vary. There is also a problem that it becomes difficult to recover a melt having a concentration.
Further, in the technology of Patent Document 2, since ice crystals are partially melted while sending air with a blower, the solute flavor component contained in the melt is diffused by the wind, and the solute component balance in the concentrate is balanced. There is a problem that it is greatly different from that before concentration.

  In view of such a problem, an object of the present invention is to provide an interfacial forward freeze concentration system that can easily cut and transport ice crystals and is excellent in storability of a solute in a melt.

The interface forward freezing and concentrating system of the present invention includes an ice crystal generating unit that generates a hollow bar-like ice crystal in a vertical pipe by circulating a solution inside the vertical pipe while cooling the outside with a refrigerant, and a lower part of the vertical pipe An on-off valve that opens and closes the opening, and an ice crystal crusher that is disposed below the vertical pipe and that crushes by placing the ice crystal on the transport surface by opening the on-off valve and letting it fall naturally from the vertical pipe In an interfacial forward freeze concentration system comprising a conveyor and an ice crystal melting portion that partially melts the ice crystals to obtain a melt having a desired concentration, the system includes convex portions arranged at predetermined intervals on the transport surface. The ice crystal is naturally cut in the vicinity of the lower opening by hooking the lower end of the ice crystal that naturally falls from the lower opening to the projecting portion.
In addition, a height adjusting mechanism for changing a relative distance from the lower opening to the conveying surface is provided.
In addition, the ice crystal melting part contains a container containing the cut ice crystal in a sealed state with respect to the outside air, a heating mechanism for heating the inside of the container, and stirring for stirring the ice crystal in the container And a mechanism.

According to the interfacial forward freeze concentration system of the present invention, the hollow bar-shaped ice crystals are cut using the convex portions provided on the transport surface, so that there is an advantage that the apparatus configuration is simplified and the manufacturing cost can be suppressed. In addition, since the ice crystal is cut on the transfer surface, the cut ice crystal can be transferred to the ice crystal melting part by the ice crystal crushing conveyor while it is placed on the transfer surface, making it easy to automate the equipment during actual production. Become.
In addition, the hardness of ice crystals varies depending on the concentration of the solution and the type / component ratio of the solute as described above, but the cutting length is constant regardless of the hardness of the ice crystals by making the convex spacing constant. Can be. Accordingly, the concentration adjustment of the ice crystal melt performed in the ice crystal melting part is facilitated, and the melt having a desired concentration can be recovered.
If the height adjusting mechanism is provided, the cutting length of the ice crystals can be adjusted according to the conveying capacity of the ice crystal crushing conveyor and the processing capacity of the ice crystal melting part.

In addition, if a container for containing ice crystals in a hermetically sealed state with respect to the outside air is provided, compared to a case where ice crystals are partially melted while blowing air with a blower as in a conventional apparatus, The situation that the flavor component of the contained solute is blown by the wind and diffused in the atmosphere can be prevented, and the solute component balance in the melt can be made substantially equal to the component balance of the solution before concentration.
In addition, when ice crystals generated by the interfacial forward freeze concentration method are slowly melted over time, a high-concentration melt containing a large amount of solute elutes first, and the concentration gradually decreases. Are known. Therefore, when the ice crystals are heated while stirring using the heating mechanism and the stirring mechanism, the temperature in the container can be made substantially uniform, so that a melt with a desired concentration can be easily collected.

Front view showing configuration of interfacial forward freeze concentration system Side view showing configuration of interfacial forward freeze concentration system The figure which shows the state which cut | disconnects and conveys a hollow rod-shaped ice crystal (a)-(e) The figure (a) which shows the state which conveys the cut | disconnected ice crystal to an ice crystal melting part, The figure (b) which shows the state in partial melting A graph showing changes in flavor patterns in La France The figure which shows the state of the ice crystal of Kaga stick tea (a) and the figure which shows the state of the ice melt from the left, the undiluted undiluted solution, and the concentrate from the left (b) Analysis results of aroma components of Kaga stick tea Graph showing aroma components such as concentrate of La France fruit juice condensate Graph showing the relationship between ice phase melting rate, concentration and yield when partial melting is performed on tomato juice Graph (a) showing alcohol content of frozen concentrated sake and graph (b) showing aroma components Graph (a) showing component analysis results of sake and table (b) showing aroma component analysis results

An embodiment of the interface forward freeze concentration system 1 of the present invention will be described.
As shown in FIG. 1 to FIG. 4, the interfacial forward freeze concentration system 1 is roughly composed of an ice crystal generation unit 10, an ice crystal crushing unit (ice crystal crushing conveyor 20), and an ice crystal melting unit 30. Depending on the positional relationship, an ice crystal conveying conveyor 40 is used as shown in FIG.
The ice crystal generation unit 10 circulates a solution inside the vertical tube 11 while cooling the outside of the vertical tube 11 with a refrigerant, thereby generating a hollow rod-shaped ice crystal 50 in the vertical tube 11.

Examples of the type of solution include an aqueous solution, fruit juice, and sake, but are not particularly limited.
Examples of the aqueous solution include fruit juice, coffee (water extract of roasted coffee beans), tea (water extract of various tea leaves), milk, and soup stock. Tea leaves may be used alone or in combination. Examples of the milk include pasteurized milk and processed milk. Dashi soup includes kombu dashi, bonito dashi, bouillon, umami extract, Japanese dashi, Western dashi, Chinese dashi, and so on. In these aqueous solutions, water-insoluble components may be suspended or dispersed. The aqueous solution may be frozen and concentrated as it is, or may be freeze-concentrated after filtering water-insoluble components.
Examples of the fruit juice include common fruit juices such as lemon juice, orange juice and apple juice.
Sake includes brewed liquor (for example, Japanese liquor (including raw sake and water adjusted)), beer, wine, cider, etc., mixed liquor (synthetic sake, sweet fruit liquor, liqueurs, miscellaneous liquor, sparkling liquor, fruit beer, etc. ).

The vertical pipes 11 are composed of a plurality (two in the present embodiment), and the vertical pipes 11 form a circulation flow path by connecting their upper and lower ends. Then, the solution in the solution tank 12 is supplied to the circulation flow path by the liquid feed pump 12 a and then circulated by the solution circulation pump 14 while measuring the flow rate by the flow meter 13.
A part of the outer peripheral surface of each vertical pipe 11 is covered with a cooling jacket 15. The cooling jackets 15 are also connected to each other by a circulation flow path, and the refrigerant in the refrigerant tank 16 is sent to the circulation flow path by the refrigerant pump 18 while measuring the temperature by the thermometer 17 and circulated. Is cooled from the outer peripheral surface side. As the refrigerant, known ones such as methanol, ethanol, isopropyl alcohol, and nybrine can be used.
In this system, the drive control of each device constituting the ice crystal generation unit 10 is performed by the control device, and the control device controls the drive of the solution circulation pump 14 to adjust the flow rate of the solution in the vertical pipe 11. In addition, the flow rate is measured by the flow meter 13. Ice crystals are generated from the inner wall surface of the vertical pipe 11 toward the center, and a hollow rod-shaped ice crystal 50 having a desired thickness is generated.

Each vertical pipe 11 is provided with an opening 11a at its lower end, and this lower opening 11a can be freely opened and closed by an on-off valve 11b.
After the ice crystal 50 is generated, the solution (concentrated liquid) in the vertical tube 11 is first taken out, and then the refrigerant is heated to warm the outer peripheral surface of the ice crystal 50. As a result, the ice crystals 50 are peeled off from the inner wall surface of the vertical tube 11, so that the on-off valve 11b of the lower opening 11a is opened and is naturally dropped by its own weight.
In order to obtain a good freeze concentration effect in the interfacial forward freeze concentration method, it is known that it is effective to reduce (slow) the growth rate of ice crystals. This is because if the ice crystal growth rate is too high, the solute uptake rate into the ice crystal will be high. On the other hand, if the ice crystal growth rate is too slow, the freeze concentration time will be long and There is also a problem that productivity decreases. It is also known that it is effective to increase (fasten) the flow rate of the solution near the freezing interface. This is because if the flow rate of the solution at the freezing interface is slow, the concentration of the solute near the freezing interface increases and the rate of solute uptake into the ice crystals increases. If the flow rate of the gas is too high, the load on the apparatus increases, and there is a problem that it is liable to cause a failure or the like.
The concentrated liquid is the remaining liquid from which a part of the water in the solution is removed as ice crystals, and can be used for the purpose of producing food and drink such as fruit juice, coffee, tea, milk, and broth depending on the type of the solution. Concentrated liquid has the advantage that it can reduce transportation cost and storage cost compared to the case of transporting and storing a solution containing a large amount of water as it is, and it is prepared mainly for that purpose. It can also be used as it is added to other foods and drinks. In addition, when the solution is sake, not only alcohol but also other extract components can be concentrated as it is by concentration, so that a high concentration sake of a new category different from distilled sake can be obtained.

The ice crystal crushing conveyor 20 is disposed below the vertical pipe 11, and opens and closes the open / close valve 11 b to naturally drop the ice crystal 50 taken out from the vertical pipe 11 to carry it on the conveying surface 21. Is provided.
Convex portions 22 are provided on the transport surface 21 at predetermined intervals (FIGS. 2 and 3A). The ice crystal 50 that spontaneously falls from the lower opening 11a when the on-off valve 11b is opened comes to rest in an upright state with its lower end surface being in contact with the transport surface 21 (FIG. 3B). In this state, most of the ice crystals 50 remain in the vertical tube 11 and only the lower end is exposed to the outside. As the transport surface 21 travels, the lower end surface of the ice crystal 50 slides relatively on the transport surface 21, and when the convex portion 22 is caught by the lower end of the ice crystal 50, On the other hand, an external force acts forward (in the traveling direction of the conveying surface 21) from the convex portion 22, and the ice crystal 50 is cut in the vicinity of the lower opening 11a due to the influence of the external force (FIG. 3 (c)).
The cut ice crystal 50 moves forward while being placed on the transport surface 21 as it is, and the ice crystal 50 in the vertical tube 11 naturally falls due to its own weight (FIG. 3D). The lower end surface (cut surface) of the fallen ice crystal remains stationary while being in contact with the transport surface 21, and is cut by the next convex portion 22 (FIG. 3 (e)). In this way, by repeating the natural fall due to the weight of the ice crystal 50 and the cutting by the convex portion 22, all the ice crystals 50 are sequentially cut to an appropriate length. Note that the cutting operation of the ice crystals 50 may be performed one by one when a plurality of vertical tubes 11 are present, or may be performed simultaneously.
In the present embodiment, a height adjusting mechanism (not shown) capable of changing the relative distance from the lower opening 11a of the vertical pipe 11 to the transport surface 21 is provided. As the height adjustment mechanism, for example, a known drive device such as an electric motor is used to adjust the vertical position of the bracket that supports the vertical pipe 11, or two front and rear around which the conveyance surface 21 is wound. What is necessary is just to adjust the position of the up-down direction of the rotating roller 23. FIG. The cutting length of the ice crystal can be changed by changing the distance from the lower opening 11a of the vertical tube 11 to the transport surface 21 using the height adjusting mechanism.

As shown in FIGS. 4A and 4B, the ice crystal melting unit 30 is provided to partially melt the cut hollow ice crystals to obtain a melt having a desired concentration.
Specifically, the ice crystal melting unit 30 is generally composed of a storage container 31, a heating mechanism 32, and a stirring mechanism 33.
The storage container 31 stores the cut ice crystal 50 in a sealed state with respect to the outside air. The shape of the container 31 is not particularly limited. For example, the container 31 has a conical shape with a diameter decreasing downward, and an upper opening 31a for introducing the ice crystals 50 is provided on the upper end surface of the container 31, and the melt is formed at the lower part. A take-out port 31b may be provided to collect the air and the inside may be sealed by closing the upper opening 31a with the lid 31c.
When the ice crystal crushing conveyor 20 is arranged near the floor surface, the ice crystal conveyance from the terminal end (front end) of the ice crystal crushing conveyor 20 to the upper opening 31a of the storage container 31 obliquely upward is performed as necessary. The conveyor 40 may be arranged separately. In this case, the ice crystals 50 are placed on the ice crystal conveying conveyor 40 and moved to the upper opening 31a and put into the storage container 31.
The heating mechanism 32 is provided to heat the inside of the storage container 31. The means for heating is not particularly limited, and for example, a heating medium may be circulated on the outer peripheral surface of the storage container 31 or a heater may be attached inside the storage container 31. The temperature in the storage container 31 can be measured by the thermometer 32a.
The stirring mechanism 33 is provided for stirring the ice crystals 50 in the container 31. The means for stirring is not particularly limited. For example, the rotating shaft 33a that is supported by the lid 31c and whose lower end reaches the inside of the container 31 is attached to the periphery of the rotating shaft 33a. Alternatively, a propeller-like stirring blade 33b may be used. The structure of the stirring blade 33b is not particularly limited. For example, the upper ends of the plurality of rod-shaped members 33c are connected by an annular ring 33d, and the lower ends are connected by a disk 33e, which corresponds to the shape of the container 31. It may be conical. Moreover, you may make it the structure which attached the rod-shaped member 33f as what is called a baffle plate to the lower surface of the cover body 31c. By using the stirring mechanism 33, the temperature distribution in the container 31 can be made more uniform.

[Development of natural aroma materials by concentrating fruit aroma components]
Next, Example 1 of the interface forward freeze concentration system of the present invention will be described.
Using this system, it is possible to develop natural aroma materials by concentrating fruit flavor condensates such as apples, peaches, La France and grapes. FIG. 5 shows the result of comparing flavor patterns of concentrated aroma components when interfacial forward freeze concentration by this system was performed on La France juice condensate and when reverse osmosis concentration was performed as a comparative example. In the reverse osmosis, the aroma balance is largely lost due to the concentration, whereas the interface forward freezing concentration by this system can be effectively concentrated while maintaining the aroma balance.

[Development of new food ingredients by concentrating palatable beverages]
Next, a second embodiment of the interface forward freeze concentration system of the present invention will be described.
When this system is used, high-quality enrichment of palatable beverages such as green tea, hojicha, black tea, and coffee becomes possible. Fig. 6 (a) shows the shape of hollow ice crystals when Kaga stick tea, a special stalk hoji tea made in Ishikawa Prefecture, is subjected to interfacial forward freeze concentration, and Fig. 6 (b) shows from the left the interface forward freeze concentration method. It is the appearance of the melted ice crystal produced, the stem Hoji tea stock solution before concentration, and the concentrated solution. FIG. 7 shows the analysis result of the aroma component. It can be seen that the uptake rate of the aroma component into the ice crystals is low, and that the concentrated reducing solution is well concentrated close to the composition of the stock solution. Such concentrated materials can be applied to ice confectionery and confectionery ingredients.

[Application of this system to solutions with low osmotic pressure]
Next, a third embodiment of the interface forward freeze concentration system of the present invention will be described.
Examples of solutions belonging to this category include fruit flavor condensate, taste drinks such as tea and coffee, seasonings such as bonito soup stock, protein solutions, etc. Among these, stem houji tea has already been described in Example 2. The foods in this category can be said to be the solution group most easily applicable to this system because the yield of 95% or more can be easily achieved by interfacial forward freezing concentration by this system. FIG. 8 is a chromatogram of a concentrated solution and a partially melted solution obtained by subjecting La France juice condensate to interfacial forward freeze concentration by this system and concentrating to about 6 times, and a stock solution as a comparative example. It can be seen that solute uptake into ice crystals is extremely small, and that effective concentration of aroma components is performed while maintaining flavor balance.

[Application of this system to a medium osmotic pressure solution]
Next, Example 4 of the interfacial forward freeze concentration system of the present invention will be described.
Many fruit juices and vegetable juices fall into this category, and since the osmotic pressure is high, the solute uptake rate into ice crystals is high, and the yield tends to decrease. This system is effective for such a solution. As a result of interfacial forward freeze concentration using this system for tomato juice (depulped pulp), the osmotic pressure was slightly high (9.9 atm) before partial concentration, and the volume concentration ratio was 1.63 times as shown in FIG. Concentration ratio was 1.49 times, and the yield was slightly low at 91%. Next, the resulting ice crystals were partially concentrated by this system, and about 25% of the ice crystals were melted, and the solute was recovered to improve the yield to 95% or more.

[Application of this system to solutions with high osmotic pressure]
Next, a fifth embodiment of the interface forward freeze concentration system 1 of the present invention will be described.
Solutions belonging to this category include high-concentration sugar solutions and sake. (Figures 10 (a) and (b) show three types of sake (pure rice sake and Daiginjo 1 and 2) subjected to interfacial forward freeze concentration by this system, and the alcohol content of the stock solution as a comparative example. It shows that the alcohol content is concentrated to about 25% on average, and the fragrance component (ethyl acetate) is also concentrated accordingly. It becomes.
Fig. 11 (a) shows the results of interfacial forward freezing and concentrating with 17.5% of the alcoholic sake, which is 17.5% of the alcohol content. It was. Further, as shown in FIG. 11 (b), fragrance components and the like can also be concentrated at substantially the same ratio, and it is understood that high quality concentration is possible.

  The present invention relates to an interfacial forward freeze concentration system that can easily cut and transport ice crystals and is excellent in preservability of a solute in a melt, and has industrial applicability.

1 Interfacial forward freeze concentration system 1
DESCRIPTION OF SYMBOLS 10 Ice crystal production | generation part 11 Vertical pipe 11a Lower opening 11b On-off valve 12 Solution tank 12a Liquid feed pump 13 Flowmeter 14 Solution circulation pump 15 Cooling jacket 16 Refrigerant tank 17 Thermometer 18 Refrigerant pump 20 Ice crystal crushing conveyor 21 Conveying surface 22 Convex part 23 Rotating roller 30 Ice crystal melting part 31 Container 31a Upper opening 31b Outlet 31c Cover 32 Heating mechanism 32a Thermometer 33 Stirring mechanism 33a Rotating shaft 33b Stirring blade 33c Rod-shaped member 33d Ring 33e Disk 33f Baffle plate 40 ice crystal conveyor 50 ice crystal

Claims (3)

An ice crystal generator that generates hollow rod-shaped ice crystals in the vertical pipe by circulating the solution inside the vertical pipe while cooling the outside with a refrigerant;
An on-off valve for opening and closing the lower opening of the vertical pipe;
An ice crystal crushing conveyor disposed below the vertical pipe, placing the crushing ice on the transport surface by crushing the ice crystal taken out from the vertical pipe by opening an on-off valve;
An interfacial forward freeze concentration system comprising: an ice crystal melting portion that partially melts the ice crystals to obtain a melt having a desired concentration;
Convex portions arranged at predetermined intervals on the transport surface, and by hooking the lower end of the ice crystal that naturally dropped from the lower opening to the running convex portion, the ice crystals are sequentially placed in the vicinity of the lower opening. Interfacial forward freeze concentration system characterized by cutting.   The interface forward freezing and concentrating system according to claim 1, further comprising a height adjusting mechanism for changing a relative distance from the lower opening to the conveying surface. The ice crystal melting part contains a container containing the cut ice crystals in a sealed state with respect to the outside air, a heating mechanism for heating the inside of the container, and a stirring mechanism for stirring the ice crystals in the container The interfacial forward freeze concentration system according to claim 1 or 2, characterized by comprising:

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