Efficient freeze concentration method

Abstract

The invention relates to a freeze concentration method. After a dilute solution is frozen into a solid state (hereinafter referred to as an ice body), heat is transferred to the ice body, and the purpose of concentration is achieved through dissolution. After the dilute solution is frozen into an ice body, heat is transferred to the ice body in a proper heat transfer mode, and the concentration effect and efficiency can be effectively improved during dissolution. And in the ice body dissolving process, the concentration of the dissolved liquid is gradually reduced from high to low. According to the requirement of the target concentration, the solutions are retained in a segmented mode, and the solutions with different concentrations are obtained. And transferring the solution meeting the target concentration to the next link for storage (utilization). Solutions which do not conform to the target concentration can be repeatedly frozen and concentrated through the method, and the concentration of the solutions continues to be increased. The method is simple to operate and high in efficiency, can be operated at normal pressure and low temperature, and is suitable for freeze concentration of heat-sensitive raw materials. For example, the freeze concentration device can be used for freeze concentration of milk, wine, fruit juice, coffee, tea beverages, Chinese herbal medicine liquid and the like.

Description

TECHNICAL FIELD

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

[0002] The existing freeze concentration method is a concentration method realized by using the solid-liquid correlation of a dilute solution and ice below the freezing point. There are mainly two methods: the suspension crystallization freeze concentration method and the progressive 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 progressive 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 removed to the liquid phase side, so that the mass concentration of the solute in the liquid phase is gradually increased. The existing freeze concentration method has a complex device structure, high equipment cost, high production cost, and low efficiency, and is less used in the application of fruit juice concentration.

[0003] In addition, when the ice body is naturally dissolved, the liquid dissolved first has a relatively high concentration. By freezing the solution into a solid state multiple times and then dissolving it, the concentration of the dilute solution can be increased, which is a freeze concentration method realized by the natural dissolution of the ice body. However, although this natural dissolution method is simple to operate, it takes a very long time, has low concentration efficiency and work efficiency, and is rarely used in industrial freeze concentration.

[0004] The freeze concentration method of the present application is a method of freezing a dilute solution into a solid state (hereinafter referred to as an ice body) and transferring heat to the ice body to achieve the concentration target by dissolution, which can greatly improve the efficiency of freeze concentration. The method of the present application has the characteristics of energy saving, simple equipment, low cost, high efficiency, and can be operated at normal pressure and low temperature, and can be used for freeze concentration of heat-sensitive raw materials. SUMMARY

[0005] The present application relates to a freeze concentration method. After freezing a dilute solution into a solid state (hereinafter referred to as an ice body), heat is transferred to the ice body to achieve the concentration target by dissolution. After the dilute solution is frozen into an ice body, heat is transferred to the ice body by an appropriate heat transfer method during dissolution, which can effectively improve the concentration effect and efficiency. During the dissolution of the ice body, the concentration of the dissolved liquid gradually decreases from high to low. According to the needs of the target concentration, the solution is taken out in stages to obtain solutions of different concentrations. The solution meeting the target concentration is transferred to the next link for storage (utilization). The solution not meeting the target concentration can be repeatedly frozen and concentrated by the method to continue to increase the concentration of the solution. The method is simple to operate, has high efficiency, and can be operated at normal pressure and low temperature, and is suitable for freeze concentration of heat-sensitive raw materials. For example, it can be used for freeze concentration of milk, wine, fruit juice, coffee, tea beverage, Chinese herbal medicine liquid, etc. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 is a cross-sectional view of a cylindrical freeze concentration device.

[0007] Figure 2 is a cross-sectional view of another cylindrical freeze concentration device.

[0008] Figure 3 is a schematic view of a freeze concentration device.

[0009] Figure 4 is a record of experimental results.

[0010] In the figure: 1 - raw material bottle (barrel), 2 - dilute solution, 3 - heating tube, 4 - heater base tray groove edge, 5 - solution outlet, 6 - sealing material, 7 - ice body, 8 - power socket protective cover, 9 - socket, 10 - temperature regulating switch, 11 - solution outlet and switch valve. DETAILED DESCRIPTION

[0011] The method is now described with reference to the accompanying schematic drawings: In the method of the present invention, a heat source placement position implementation case is provided: the heat source is placed in a position perpendicular to the "cooling surface" (from the cooling surface) away from the ice body (inside or outside the ice body). The following schematic drawing is a simple qualitative description of the heat source placement position.

[0012] Figure 1 is a cross-sectional view of a cylindrical freeze concentration device. The dilute solution is frozen into an ice body in this device. As shown in (1) in Figure 1 , when freezing the dilute solution, the "cooling surface" is: the container wall surface close to the refrigerant. When setting the heat source, it should be set in a position perpendicular to the "cooling surface" (from the cooling surface) away from the ice body. In this device, the "central axis region" of the ice body is within the range of this position: a heat source (such as a heating rod) can be set here, or multiple heat sources (multiple heat source rods) can be set, see Figure 1 (3).

[0013] Figure 2 is a cross-sectional view of a cylindrical freeze concentration device. In this device, the refrigerant is passed through the device from the central axis region from the sealed pipe, see Figure 2 (1). When freezing the dilute solution, the "cooling surface" is: the outer wall of the refrigerant pipe. The heat source can be set in the ice body close to the outer wall region of the container, or it can be set outside the container (outside the ice body), see Figure 2 (2).

[0014] Figure 3is a frozen concentration device made according to the method of the present application. The device is composed of a stock solution bottle and a heater, which is installed on the bottle cap of the stock solution bottle. The bottle cap has a solution outlet valve 11, see Figure 3 (1) in the description, Figure 3 (2) in the description, Figure 3 (3) in the description.

[0015] The specific operation is as follows: inject the dilute solution into the stock solution bottle 1, cover the bottle cap, and then keep the bottle mouth upward and send the device into the freezer. After the dilute solution is frozen into solid state (hereinafter referred to as ice body), remove the device from the freezer and place it on the platform with the bottle mouth downward. Open the power socket protection cover 8, connect the power supply through the power socket 9, and set the heating temperature through the temperature adjusting switch 10. Turn on the power switch to control the temperature of the ice body and dissolve it. The solution is discharged from the outlet valve 11 in stages to obtain solutions with different concentrations. The solution with the target concentration is transferred to the next work link. The solution that does not meet the target concentration can be further frozen and concentrated by the device to increase the concentration of the liquid.

[0016] According to the above device and method, we compare two groups of frozen concentration.

[0017] (1) Use a device with three stock solution barrels, each with a capacity of 60 liters, to fill 56 liters of thorny grape juice (refractive sugar content 14.3%). The stock solution barrels of the three devices are named A barrel, B barrel, and C barrel, respectively. Use a device with one stock solution barrel with a capacity of 30 liters to fill 25 liters of thorny grape juice (refractive sugar content 14.3%). The stock solution barrel of this device is named D barrel. Send the thorny grape juice in barrels A, B, C, and D (devices) into the freezer.

[0018] When the thorny grape juice is frozen into ice body, remove the thorny grape juice ice bodies of the four devices (four barrels) from the freezer, and then conduct a comparison experiment of the concentration effect of dissolution.

[0019] (1) A barrel (without heating) uses natural dissolution.

[0020] (2) B, C, and D barrels are heated and dissolved according to the method of the present application. B barrel uses a heating temperature of 45 degrees Celsius (the temperature of the heating rod), and C and D barrels use a heating temperature of 65 degrees Celsius (the temperature of the heating rod) to heat and dissolve the ice body. When the ice body is dissolved, the temperature of the flowing solution is monitored and kept below 0 degrees Celsius.

[0021] Set two target concentrations for recording. The first target concentration is sugar content (refractive sugar content) 30%, and the second target concentration is sugar content (refractive sugar content) 18%. Collect the liquid flowing out of the ice bodies of barrels A, B, C, and D, and the experimental results are recorded in Figure 4 Table 1, Table 2, Table 3, and Table 4 in the description.

[0022] (1) Comparing the recorded data of barrels A, B, and C, we find that

[0023] (1)Three barrels of the first target concentration (refractive sugar 30%) of the Vitis davidii Foex juice volume, respectively: 0.5 liters, 14.1 liters, 13.2 liters, accounting for the volume of the original liquid: 4.5%, 25.18%, 23.6%. It can be seen that the concentration effect of the method of the application is compared with the natural dissolution method (the existing "ice slip" technology), and the advantage in the high concentration section is very obvious: the volume of the high concentration section solution obtained by the application is 26 times that of the existing method (natural dissolution method).

[0024] (2)The ice body dissolution separation speed (L / hour) is compared: 0.5L / hour, 1.47L / hour, 1.65L / hour. The ice body dissolution separation speed of the high concentration section solution of the method of the application is more than 2.94 times that of the existing method (natural dissolution method).

[0025] (3)The data of the three barrels of the sugar content (refractive sugar) below 5% are 19.6%, 49.46%, and 44.8% respectively. That is, it can be seen that the concentration separation effect of the application is significantly higher than that of the natural dissolution method, more than 2.3 times.

[0026] (B) Comparison of the recorded data of barrels B, C and D

[0027] (4)Comparing the data of barrels B and C, it can be seen that when the ice body volume is the same, the higher the temperature of the heater, the faster the dissolution and separation speed of the ice body. The outlet temperature of the solution is lower than 0 degrees Celsius.

[0028] (5)Comparing the data of barrels B and D, it can be seen that when the heating temperature is constant, the smaller the ice body volume, the faster the dissolution and separation speed of the ice body.

[0029] It can be seen that after the dilute solution is frozen into ice body, heat is transferred to the ice body for dissolution, which greatly improves the efficiency of freezing concentration. The method has the advantages of simple equipment, low equipment cost, easy operation, high efficiency and low production cost.

[0030] The above embodiment is only one of the examples and is not used to limit the application. Any modification and equivalent replacement, improvement made within the spirit and principle of the application shall be included in the protection of the application.

Claims

1. The present invention relates to a freeze concentration method. This freeze concentration method involves freezing a dilute solution into a solid state (hereinafter referred to as an ice body) and then transferring heat to the ice body to achieve the desired concentration through dissolution. After the dilute solution is frozen into the ice body, using an appropriate heat transfer method to transfer heat to the ice body during dissolution can effectively improve the concentration effect and efficiency. During the ice body dissolution process, the concentration of the dissolved liquid gradually decreases from high to low. Based on the target concentration, the solution is collected in sections to obtain solutions of varying concentrations. Solutions that meet the target concentration are transferred to the next stage for storage (utilization). Solutions that do not meet the target concentration can be repeatedly freeze concentrated using this method to further increase the solution concentration. This method is simple to operate and highly efficient. It can also be operated at normal pressure and low temperatures, making it suitable for freeze concentration of heat-sensitive raw materials.

2. The freeze concentration method according to claim 1, wherein: After the dilute solution is frozen into a solid state (hereinafter referred to as ice body), when heat is transferred to the ice body to melt it, the heat transfer method includes (but is not limited to the methods listed): directly heating the ice body, heating the ice body after crushing it, or setting a heat source at a specific location inside or outside the ice body for heating, etc.

3. The freeze concentration method according to claim 1, wherein: The "specific direction" where the heat source is set is a directional area. For example, when a dilute solution is frozen into ice, the "specific direction" is the direction perpendicular to the "cooling surface" (hereinafter referred to as the direction away from the "cooling surface"), toward the ice. This area can be inside or outside the ice, farthest from the "cooling surface," or farther away. Similarly, when a dilute solution is frozen into ice, based on the solute content of the ice, the "specific direction" is the direction from the area with low solute content (near the "cooling surface") toward the area with high solute content. This area can be the direction with the highest solute content or a higher solute content; it can be inside or outside the ice. These two directions refer to the same area.

4. The freeze concentration method according to claim 1, wherein: One or more heat sources can be set as needed.

5. The freeze concentration method according to claim 1, wherein: A dilute solution can be placed in a container pre-installed with a heat source and then frozen into ice. The heat source in the device must be positioned away from the "cooling surface" when the dilute solution is frozen into ice.

6. The freeze concentration method according to claim 1, wherein: After the dilute solution is frozen into an ice body in the container, the heat source can be installed away from the "cooling surface" by drilling holes in the ice body (or other mechanical methods).

7. The freeze concentration method according to claim 1, wherein: When transferring heat to the ice body, gradually increasing the temperature of the heat source from a low temperature (slightly above the "eutectic point" temperature) can improve the concentration effect.

8. The freeze concentration method according to claim 1, wherein: Under the same heat transfer conditions, changing the size and shape of the dilute solution container of the freeze concentration device can affect the effect and efficiency of freeze concentration.

9. The freeze concentration method according to claim 1, wherein: This method is suitable for freeze concentration and separation and purification of heat-sensitive raw materials. For example, it can be used for freeze concentration and separation and purification of milk, wine, juice, coffee, tea beverages, Chinese herbal medicine liquids, etc.

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