Freeze concentration method

Abstract

The present invention relates to the technical field of freeze concentration, and specifically relates to a freeze concentration method. By means of a negative correlation between a melting point and a solute concentration, a dilute solution is frozen into a solid (ice) or a solid-liquid mixture (ice + concentrated solution), a heat source is arranged at a specific location of the solid or the solid-liquid mixture for heating, and freeze concentration of the dilute solution is achieved by means of dissolution and separation. The method improves the efficiency of freeze concentration and separation purification, is easy to operate, and facilitates application in the fields of food, cosmetics, biomedicine, environmental protection treatment, etc.

Description

Freeze concentration method TECHNICAL FIELD

[0001] The present application belongs to the technical field of freeze concentration, in particular to a freeze concentration method. BACKGROUND

[0002] The freeze concentration method in the prior art is a concentration technology realized by using the solid-liquid correlation of dilute solution and ice below the freezing point. There are mainly two ways: suspension crystallization freeze concentration method and gradual freeze concentration method. The principle of the suspension crystallization freeze concentration method is that when the dilute solution is frozen, the free small ice crystals suspended in the liquid are continuously removed, so that the concentration of the liquid is increased. The principle of the gradual freeze concentration method is that when the dilute solution is frozen, with the generation and growth of the ice layer on the cooling surface, the solute near the solid-liquid interface is excluded to the liquid phase side, resulting in the gradual increase of the solute mass concentration in the liquid phase. The existing freeze concentration method has complex equipment structure, high equipment cost and production cost, and low efficiency.

[0003] When the ice body is naturally dissolved, the solution with relatively high concentration will be dissolved first. By freezing the solution into solid multiple times and then dissolving it, the concentration of the dilute solution can be increased, which is a freeze concentration method through the natural dissolution of ice body. However, although this method is simple to operate, it takes a very long time and has low working efficiency, so it is rarely used in industrial freeze concentration.

[0004] In addition, some public information has devices and methods for heating and dissolving frozen materials to produce concentrated solutions, but because of the defects in the method, the effect and efficiency of freeze concentration are not high. In the device and method disclosed in the patent application with publication number JP2004351383A, steam and hot gas are used to heat and dissolve the frozen materials. This method does not take into account that the surface and internal structure of the frozen materials formed by freezing will affect the solution separation effect and efficiency of the heated dissolution of the frozen materials. The ice layer formed on the surface of the frozen materials and adjacent to the container wall will be more compact than the ice body inside the frozen materials, and the solute content of the ice layer will be lower. The heat transfer direction of the heating method used in this method is that the heat is transferred from the low-solute ice layer to the frozen materials. Such heat transfer will obviously seriously affect the effect and efficiency of the heated dissolution of the frozen materials, thereby affecting the effect and efficiency of freeze concentration, which will affect the efficiency of industrial production and promotion. SUMMARY

[0005] To solve the problems in the prior art, the main purpose of the present application is to provide a freezing concentration method, which utilizes the negative correlation between the melting point and the solute concentration, freezes the dilute solution into a solid (ice body) or a solid-liquid mixture (ice body + concentrated solution), sets a heat source at a specific orientation of the solid or solid-liquid mixture to realize heating, dissolving and separation, realizes the freezing concentration of the dilute solution, and improves the efficiency of the freezing concentration.

[0006] To solve the above technical problems, according to one aspect of the present application, the present application provides the following technical solutions:

[0007] A freezing concentration method, comprising the following steps:

[0008] S1, freezing a dilute solution to obtain a solid or a solid-liquid mixture;

[0009] S2, setting a heat source at a specific orientation of the solid or solid-liquid mixture to realize heating, segmenting and taking the solution, and obtaining solutions with different concentrations;

[0010] S3, transferring the solution meeting the target concentration to the next link (backup); the solution not meeting the target concentration is repeated with steps S1-S2 to continue to improve the concentration of the solution.

[0011] As a preferred scheme of the freezing concentration method according to the present application, in the step S2, the specific orientation is a description of a directional area: from the cooling surface when the dilute solution is frozen into a solid or a solid-liquid mixture, the specific orientation area is the area away from the cooling surface in the direction of the solid or solid-liquid mixture (except for the solid layer with low solute content adjacent to the cooling surface). This area can be inside or outside the solid or solid-liquid mixture (related to the position of the cooling surface).

[0012] As a preferred scheme of the freezing concentration method according to the present application, in the step S2, the heat source set at the specific orientation, the heat transfer direction of the heat source is characterized in that when heat is transferred to the solid or solid-liquid mixture, the heat is preferably not first transferred to the solid layer with low solute content in the solid or solid-liquid mixture.

[0013] As a preferred scheme of the freezing concentration method according to the present application, in the step S2, the heat source set at the specific orientation is in the following manner:

[0014] inserting the heat source on the solid or solid-liquid mixture obtained by freezing;

[0015] or processing (e.g. drilling, cutting) the position where the heat source needs to be set on the solid or solid-liquid mixture, and then putting (inserting) the heat source;

[0016] or pre-setting the heat source at the position where the heat source needs to be set during the freezing process.

[0017] As a preferred solution of the freeze concentration method, in the step S2, the shape of the heat source includes: point, line (column), surface (plate), spherical.

[0018] As a preferred solution of the freeze concentration method, in the step S1, when the heating temperature is lower than the freezing point or the eutectic point, the flow guide channels can be set on the solid or solid-liquid mixture obtained by freezing, which can improve the effect of freeze concentration and separation and purification.

[0019] As a preferred solution of the freeze concentration method, in the step S1, the flow guide channels are directly processed on the solid or solid-liquid mixture obtained by freezing; the processing methods include drilling, threading, inserting, and piercing.

[0020] As a preferred solution of the freeze concentration method, in the step S1, the flow guide channels are set by inserting the flow guide device on the solid or solid-liquid mixture obtained by freezing.

[0021] As a preferred solution of the freeze concentration method, in the step S1, the flow guide channels are set by crushing the solid layer part of the solution outflow direction after the solid or solid-liquid mixture is heated.

[0022] As a preferred solution of the freeze concentration method, in the step S1, the flow guide channels are set by pre-setting the flow guide channels or the flow guide device with flow guide function during the freezing process.

[0023] As a preferred solution of the freeze concentration method, in the step S2, after the solid or solid-liquid mixture is heated, the solution is separated and flows out in the following ways: natural outflow, negative pressure extraction, or centrifugal separation.

[0024] To solve the above technical problems, according to another aspect of the present application, the present application provides the following technical solutions:

[0025] The freeze concentration method is applied in the fields of food, cosmetics, biological medicine, environmental protection treatment, etc.

[0026] The freeze concentration method is applied in the fields of milk, wine, fruit juice, coffee, tea, beverage, soy milk, chemical liquid, Chinese herbal medicine liquid, plant extract, seawater desalination, wastewater treatment, etc.

[0027] The freeze concentration method is applied in the field of freeze concentration and separation and purification of heat-sensitive raw materials.

[0028] The application of the freezing concentration method to the freezing concentration and separation and purification of milk, wine, fruit juice, coffee, tea, beverage, soybean milk, soybean milk, chemical liquid, Chinese herbal medicine liquid, plant extract, seawater desalination, wastewater treatment, etc.

[0029] The beneficial effects of the application are as follows:

[0030] The application provides a freezing concentration method, which utilizes the negative correlation between the melting point and the solute concentration, freezes a dilute solution into a solid (ice body) or a solid-liquid mixture (ice body + concentrated solution), sets a heat source at a specific orientation of the solid or solid-liquid mixture for heating, and realizes the freezing concentration of the dilute solution through dissolution and separation. The method improves the efficiency of freezing concentration and separation and purification, is simple to operate, and is convenient for application in the fields of food, cosmetics, biological medicine, environmental protection treatment, etc. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments will be described below in a clear and complete manner. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0032] The application provides a freezing concentration method, which breaks the traditional freezing concentration thinking, improves the efficiency of freezing concentration and separation and purification, is simple to operate, and is convenient for application in the fields of food, cosmetics, biological medicine, environmental protection treatment, etc.

[0033] In order to more clearly express the concept of a specific orientation, the following two example schemes are given:

[0034] (1) A cylindrical freezing device: The dilute solution is frozen into a solid or a solid-liquid mixture in the device. When the dilute solution is frozen, the refrigerant is located outside the dilute solution container in the device, and the cooling surface is the container wall surface close to the refrigerant. When the heat source is set, it is set in a specific orientation area, which is the area away from the cooling surface from the cooling surface of the solid or solid-liquid mixture. In the device, the central axis of the solid or solid-liquid mixture and the surrounding area are within the range of this area: that is, the central axis and the surrounding area in the ice body, except for the solid layer with low solute content formed close to the cooling surface, which can be set in this area. A heat source (heating rod) or multiple heat sources (multiple heat source rods) can be set.

[0035] (2) A cylindrical freezing device: In this device, the coolant is passed through the device from the center axis region of the sealed pipe, and the cooling surface is the outer wall of the coolant pipe when the dilute solution is frozen into a solid or solid-liquid mixture. The heat source is arranged in a specific orientation region, which is the region away from the cooling surface from the solid or solid-liquid mixture. That is, the heat source can be arranged in the ice body near the outer wall of the container, or outside the outer wall of the container. In the solid (ice body), the solid layer with low solute content formed near the outer wall of the coolant pipe (cooling surface) is not in the specific orientation range.

[0036] The technical solutions of the present application are further described below in conjunction with specific examples.

[0037] Example 1

[0038] A method for freezing and concentrating a grape juice, 56 L of grape juice with a refractive sugar degree of 14.3% is placed in a cylindrical container and frozen into a cylindrical solid at -18°C in a freezing chamber. A linear (or columnar) heat source is arranged in the axial center and the surrounding area of the cylindrical solid (i.e. the specific orientation) to heat, with a heat source temperature of 45°C. The temperature of the solution flowing out during the ice body dissolution process is maintained below 0°C. Two target concentrations are recorded, the first target concentration is a refractive sugar degree of 30%, and the second target concentration is a refractive sugar degree of 18%. The liquid flowing out during dissolution is collected, and the specific conditions are shown in Table 1.

[0039] Table 1 Specific conditions of the segmented solution in Example 1

[0040] Example 2

[0041] The difference from Example 1 is that the heat source temperature is 65°C.

[0042] The liquid flowing out during dissolution is collected, and the specific conditions are shown in Table 2.

[0043] Table 2 Specific conditions of the segmented solution in Example 2

[0044] Example 3

[0045] The difference from Example 2 is that the amount of grape juice is 25 L.

[0046] The liquid flowing out during dissolution is collected, and the specific conditions are shown in Table 3.

[0047] Table 3 Specific conditions of the segmented solution in Example 3

[0048] Comparative Example 1

[0049] The difference from Example 1 is that the heat source is not arranged in a specific orientation, and natural dissolution is adopted.

[0050] The dissolved liquid is collected, and the details are shown in Table 4.

[0051] Table 4 shows the details of the segmented solution of Comparative Example 1

[0052] Example 4

[0053] A freezing concentration method of a wine of a grapevine, 55L of the wine of the grapevine with an alcohol degree of 14.8%vol is filled into a cylindrical container and frozen into a cylindrical solid-liquid mixture at -18℃ in a freezing chamber. At this time, the surface of the original liquid of the wine of the grapevine and the wine of the grapevine adjacent to each peripheral surface of the container are frozen into ice layers, and ice crystals growing from the ice layers are also filled in the interior, in which the liquid not frozen into solid is wrapped. The container is moved out of the freezing chamber, a linear (or columnar) heat source is arranged in a specific orientation (the specific orientation area in which the heat source is arranged is the area near the central axis of the container and the periphery thereof in this example) to heat and dissolve, the temperature of the heat source is 35℃, and the temperature of the solution flowing out during the dissolving process is maintained below 0℃. The dissolved liquid is collected, and the details are shown in Table 5.

[0054] Table 5 shows the details of the segmented solution of Example 4

[0055] In the above examples, Example 1 (grape juice), Example 2 (grape juice), Example 3 (grape juice), and Comparative Example 1 (grape juice) are all frozen into solids; and Example 4 (wine of a grapevine) is frozen into a solid-liquid mixture. After the freezing is completed, a heat source is arranged in a specific orientation thereof to transfer heat to dissolve and separate. The dissolving conditions are recorded in Table 1, Table 2, Table 3, Table 4, and Table 5, respectively.

[0056] From the above examples and comparative examples, it can be seen that:

[0057] The volumes of the grape juice of the first target concentration (refractive sugar degree of 30%) obtained by Comparative Example 1 and Examples 1-2 are 2.5L, 14.1L, and 13.2L, respectively, accounting for 4.46%, 25.18%, and 23.57% of the volume of the original liquid, respectively. It can be seen that: the concentration effect of the method of the present application is compared with the natural dissolution method (Comparative Example 1, the existing “ice slip” technology), and the advantage in the high concentration segment is very obvious: the volume of the solution in the first target concentration segment obtained by Example 1 of the present application is 5.64 times that of Comparative Example 1 (natural dissolution method).

[0058] The dissolution separation speed (L / h) of the first target concentration (refractive sugar degree of 30%) of the akeberry juice obtained by the comparative example 1 and the examples 1-2 is respectively: 0.5 L / h, 1.47 L / h, 1.65 L / h, and the ice body dissolution separation speed of the solution in the first target concentration section of the example 2 is 3.3 times of that of the comparative example 1 (natural dissolution method).

[0059] The volume proportion of the akeberry juice with the refractive sugar degree <5% obtained by the comparative example 1 and the examples 1-2 is respectively: 34.43%, 49.46%, 49.64%, and it can be seen that the concentration separation effect of the application is higher than that of the natural dissolution method.

[0060] It can be seen from the examples 1-2 that when the volume of the original solution is the same, the temperature of the heat source is increased, and the dissolution separation speed of the ice body is accelerated.

[0061] It can be seen from the examples 2-3 that when the temperature of the heat source is constant, the smaller the volume of the ice body is, the faster the dissolution separation speed of the ice body is.

[0062] It can be seen from the example 4 that the akeberry wine is frozen into a solid-liquid mixed body (the surface is wrapped by an ice layer) at-18℃, then is moved out of the freezing warehouse, and then a hole (which is also a solution separation outlet channel) that can install a linear (or columnar) heat source is drilled on the central axis of the container and the surrounding area (the area is a specific orientation area where the heat source is arranged), and the akeberry wine concentrated solution which is not frozen into a solid is separated and flows out from the hole channel, for example, the first section solution in table 5 is the akeberry wine with the alcohol degree of 26%vol, and the volume proportion is 49.45%. Compared with the original akeberry wine with the alcohol degree of 14.8%vol, the alcohol degree is increased by 75.68%. After the first section solution is separated, the linear (or columnar) heat source is inserted into the hole (located in the specific orientation area), and the heat is transferred to the separated solid, and the solution is sequentially collected, and the second section solution is the akeberry wine with the alcohol degree of 6.98%vol, and the volume proportion is 13.20%. The fourth section solution is the akeberry wine with the alcohol degree of 0.45%vol, and the volume proportion is 17.75%. Therefore, the effect and efficiency of increasing the alcohol degree of the fermented wine by heating and dissolving the akeberry wine frozen into a solid-liquid mixed body are also better than those of the traditional method.

[0063] The application utilizes the negative correlation between the melting point and the solute concentration in the solution, and realizes the freezing concentration of the dilute solution by freezing the dilute solution into a solid (ice body) or a solid-liquid mixed body (ice body + concentrated solution), heating by arranging the heat source in the specific orientation of the solid or solid-liquid mixed body, and dissolving and separating.

[0064] The above merely describes the preferred embodiments of the present application, and is not intended to limit the patent scope of the present application. Any equivalent structural variations or direct / indirect applications in other related technical fields based on the content of the present application description are included in the patent protection scope of the present application.

Claims

1. A freeze concentration method characterized by, The method comprises the following steps: S1, freezing a dilute solution to obtain a solid or a solid-liquid mixture; S2, heating the solid or the solid-liquid mixture at a specific orientation, segmenting and collecting the solution to obtain solutions with different concentrations; S3, transferring the solution with the target concentration to the next step, and repeating steps S1-S2 to continue to increase the concentration of the solution.

2. The freeze concentration method according to claim 1, characterized by, In step S2, the specific orientation is a directional area, which is an area away from the cooling surface of the solid or the solid-liquid mixture when the dilute solution is frozen into a solid or a solid-liquid mixture. The area is inside or outside the solid or the solid-liquid mixture.

3. The freeze concentration method according to claim 1, characterized by, In step S2, the heat source is set at a specific orientation, and the heat transfer direction is characterized in that when heat is transferred to the solid or the solid-liquid mixture, the heat is not first transferred to the solid layer with low solute content in the solid or the solid-liquid mixture.

4. The freeze concentration method according to claim 1, characterized by, In step S2, the heat source is set at a specific orientation in the following ways: inserting the heat source into the solid or the solid-liquid mixture obtained by freezing; or processing the position where the heat source needs to be set on the solid or the solid-liquid mixture, and then placing the heat source; or pre-setting the heat source at the position where the heat source needs to be set during freezing.

5. The freeze concentration method according to claim 2, characterized by, In step S2, the shape of the heat source includes point, line, surface, and sphere.

6. The freeze concentration method of claim 1, wherein, In step S2, after the solid or the solid-liquid mixture is heated, the solution is separated and flows out in the following ways: natural flow, negative pressure extraction, or centrifugal separation.

7. The freeze concentration method of claim 1, wherein, In step S1, a flow guide channel is set on the solid or the solid-liquid mixture obtained by freezing.

8. Application of the freeze concentration method of any one of claims 1-7 in the fields of food, cosmetics, biomedicine, and environmental protection.

9. Application of the freeze concentration method of any one of claims 1-7 in the fields of milk, wine, fruit juice, coffee, tea, soy milk, chemical liquid, Chinese herbal medicine liquid, plant extract, seawater desalination, and wastewater treatment.

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