Freeze concentration method

Abstract

The invention belongs to the technical field of freeze concentration, and relates to a freeze concentration method, which comprises the following steps: freezing a dilute solution to obtain a solid or a solid-liquid mixture, crushing the solid or solid-liquid mixture obtained by freezing, or firstly separating the solid-liquid mixture and then crushing the solid, and adopting dry gas as an energy medium, and penetrating the crushed solid and transferring heat, and staged reserving the solution to realize freezing concentration of the dilute solution. The method improves the efficiency of freeze concentration and separation purification, is simple to operate, and can be conveniently applied to the fields of food, cosmetics, biological medicine, petrochemical industry, environment-friendly treatment and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of freeze concentration, and in particular relates to a freeze concentration method. Background Art

[0002] Among the existing freeze concentration methods, there are mainly two types of freeze concentration methods with two different physical principles. The first type: a concentration technology that uses the solid-liquid phase relationship of a substance below the crystallization point (such as using an aqueous solution at the freezing point); for example, when the solvent is water, the concentration is achieved by freezing the water into ice crystals and removing the solvent (water) in a solid form through solid-liquid separation (separation of ice crystals from concentrated solution). The second type: a technical method for freeze concentration that uses the negative correlation between the melting point and the solute content (concentration); that is, a method of heating and dissolving the frozen material and collecting dissolved solutions of different concentrations to achieve a concentrated freeze concentration method.

[0003] The first freeze concentration method is a concentration technology that uses the solid-liquid phase relationship between a dilute solution and ice below the freezing point. There are two main methods: suspended crystallization freeze concentration and progressive freeze concentration. The principle of the suspended crystallization freeze concentration method is that when a dilute solution is frozen, the free small ice crystals suspended in the liquid are continuously removed to increase the liquid concentration. The principle of the progressive freeze concentration method is that when a dilute solution is frozen, as the ice layer is generated and grows on the cooling surface, the solute near the solid-liquid interface is removed to the liquid phase side, resulting in a concentration method in which the mass concentration of the solute in the liquid phase gradually increases. The existing freeze concentration methods have complex equipment structures, high equipment costs and production costs, and low efficiency.

[0004] The second freeze concentration method: using the negative correlation between melting point and solute content (concentration), concentration is achieved by heating, dissolving and separating the frozen material. For example, when ice melts naturally, a relatively high concentration solution will be dissolved first. Using this phenomenon, the concentration of the dilute solution can be increased by freezing the solution into a solid and then dissolving it multiple times. This is a freeze concentration method using the natural dissolution of ice. In addition, the natural dissolution of ice is a way of dissolving by heat. Similarly, heating and dissolving ice in other ways will also produce a concentrated solution, achieving freeze concentration. At present, the concentration effect and efficiency of this method are very low.

[0005] The above two freeze concentration methods based on different physical principles have a major problem: the effect and efficiency of freeze concentration are low. In particular, the existing freeze concentration method of heating and dissolving (traditional conventional heating method) has a lower concentration effect and efficiency than the existing method of using the solid-liquid phase relationship of the substance below the crystallization point (such as using the aqueous solution at the freezing point) to achieve concentration.

[0006] The reason that affects the concentration effect and efficiency of the first freeze concentration method is that the physical principle it adopts inevitably leads to the problem of solute entrainment during solid-liquid separation. The separation effect of ice crystals and the control of solute loss caused by ice crystal entrainment are extremely important for the successful application of freeze concentration under this physical principle, which is also one of the reasons for the complex structure, high equipment cost and complex operation of existing freeze concentration equipment.

[0007] The second freeze concentration method can solve the solute entrainment problem of the first method. However, there are factors that affect the concentration effect and efficiency of the second freeze concentration method: factors such as the dense ice layer with low solute content on the cooling surface of the frozen material and the solid structure inside the frozen material will hinder the heat transfer when it is heated and dissolved, as well as the separation and outflow of the dissolved solution of the frozen material. These two hindering factors seriously affect the concentration effect and efficiency of the freeze concentration under this method.

[0008] The public document (application number CN202411098563.9) adopts a heating method of setting a heat source at a specific position of a solid or solid-liquid mixture frozen from a dilute solution, the public document (application number CN202411098562.4) adopts a method of setting a guide channel in a solid or solid-liquid mixture frozen from a dilute solution and heating it, the public document (application number CN202411098560.5) adopts a method of crushing and heating a solid or solid-liquid mixture frozen from a dilute solution, etc., which effectively solves the problems of hindering heat transfer and hindering the separation and outflow of the dissolved solution in the heating and dissolving process of the aforementioned frozen materials, greatly improving the effect and efficiency of freeze concentration.

[0009] There are three ways to transfer heat: heat conduction, heat convection and heat radiation. For the same substance, under different physical states and physical conditions, the use of appropriate heat transfer methods will improve the effect and efficiency of heat transfer. For example, in the public document (application number CN202411098560.5), the method of crushing and heating the solid or solid-liquid mixture frozen from the dilute solution is essentially to increase the heating area of ​​the solid (ice body) during heating and dissolution by the crushing method, solve the effect of the dense ice layer with low solute content on the surface of the solid or solid-liquid mixture on the heat transfer during heating and dissolution, and solve the obstructive effect of the surface and internal solid structure of the solid or solid-liquid mixture on the heat transfer and the separation and outflow of the dissolved solution; this method has greatly improved the effect and efficiency of freeze concentration using traditional conventional heating methods, and solves the problem that freeze concentration using traditional conventional heating methods is difficult to obtain large-scale and industrialized applications due to the concentration effect and efficiency problems.

[0010] However, there are irregular arrangements (stacking) of the crushed solid particles and gaps (including air in the gaps) between the crushed solid particles. The existence of these phenomena has an adverse effect on the conduction or radiation of heat between the crushed solid particles, thereby affecting the further improvement of the freeze concentration effect and efficiency. Summary of the invention

[0011] In order to solve the problems existing in the prior art, the main purpose of the present invention is to propose a freeze concentration method, which solves the problem that the crushed solid particles are irregularly arranged (stacking) and there are gaps (including air in the gaps) between the crushed solid particles, which have an adverse effect on heat conduction or radiation, thereby affecting the further improvement of the freeze concentration effect and efficiency.

[0012] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions: A freeze concentration method comprises the following steps: S1, freezing the dilute solution to obtain a solid; S2, crushing the frozen solid, using dry gas as an energy medium to penetrate the crushed solid and transfer heat, and collecting solutions in sections to obtain solutions of different concentrations; S3. The solution that meets the target concentration is transferred to the next stage; for the solution that does not meet the target concentration, steps S1-S2 are repeated to continue to increase the solution concentration.

[0013] A freeze concentration method comprises the following steps: S1, freezing the dilute solution to obtain a solid-liquid mixture; S2, crushing the solid-liquid mixture obtained by freezing and performing solid-liquid separation, using dry gas as an energy medium to penetrate the crushed solid and transfer heat, and retaining solutions in sections to obtain solutions of different concentrations; S3. The solution that meets the target concentration is transferred to the next stage; for the solution that does not meet the target concentration, steps S1-S2 are repeated to continue to increase the solution concentration.

[0014] A freeze concentration method comprises the following steps: S1, freezing the dilute solution to obtain a solid-liquid mixture; S2, performing solid-liquid separation on the solid-liquid mixture, crushing the solid after solid-liquid separation to obtain crushed solid, using dry gas as energy medium to penetrate the crushed solid and transfer heat, and retaining solutions in sections to obtain solutions of different concentrations; S3. The solution that meets the target concentration is transferred to the next stage; for the solution that does not meet the target concentration, steps S1-S2 are repeated to continue to increase the solution concentration.

[0015] As a preferred embodiment of the freeze concentration method described in the present invention, the drying gas is air or nitrogen.

[0016] As a preferred embodiment of the freeze concentration method of the present invention, the dry gas can be processed and then recycled.

[0017] To solve the above technical problem, according to another aspect of the present invention, the present invention provides the following technical solution: An application of the above freeze concentration method in the fields of food, cosmetics, biomedicine, petrochemicals, environmental protection treatment, etc.

[0018] The above-mentioned freezing concentration method is applied in the fields of milk, vinegar (including vinegar-containing food, vinegar beverages, condiments, etc.), wine, beverages (such as juice, coffee, tea, soy milk, soy milk, etc.), chemical liquid, Chinese herbal medicine liquid, plant extract, petroleum purification, chemical purification, seawater purification, wastewater treatment, etc.

[0019] An application of the freeze concentration method in the field of freeze concentration and separation and purification of heat-sensitive raw materials.

[0020] The above-mentioned freeze concentration method is applied in the fields of freeze concentration and separation and purification of milk, vinegar (including vinegar-containing food, vinegar beverages, condiments, etc.), alcoholic beverages (such as juice, coffee, tea, soy milk, soy milk, etc.), chemical liquids, Chinese herbal medicine liquids, plant extracts, seawater purification, petroleum purification, chemical purification, wastewater treatment, etc.

[0021] The beneficial effects of the present invention are as follows: The present invention proposes a freeze concentration method, wherein a dilute solution is frozen to obtain a solid or a solid-liquid mixture, the frozen solid or solid-liquid mixture is crushed or the solid-liquid mixture is separated before the solid is crushed, a dry gas is used as an energy medium, the crushed solid is penetrated and heat is transferred, and the solution is retained in sections to achieve freeze concentration of the dilute solution. The present invention uses a dry gas as an energy medium and allows it to penetrate the crushed solid to transfer heat, which solves the problem that the irregular arrangement (stacking) of crushed ice particles between the crushed solid particles and the presence of gaps (including air in the gaps) between the crushed solid particles have an adverse effect on heat conduction or radiation, further improves the effect and efficiency of freeze concentration, is simple to operate, and is convenient for application in the fields of food, cosmetics, biomedicine, petrochemicals, environmental protection treatment, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some preferred embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0023] Figure 1 Schematic diagram of gas circulation in the freeze concentration method of the present invention.

[0024] In the figure, 1-dissolving device, 2-gas drying equipment, 3-gas temperature regulating equipment, 4-blower, 5-solution, 6-condensate.

[0025] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0026] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] One embodiment of the present invention provides a freeze concentration method, comprising the following steps: S1, freezing the dilute solution to obtain a solid; S2, crushing the frozen solid, using dry gas as an energy medium to penetrate the crushed solid and transfer heat, and collecting solutions in sections to obtain solutions of different concentrations; S3. The solution that meets the target concentration is transferred to the next stage; for the solution that does not meet the target concentration, steps S1-S2 are repeated to continue to increase the solution concentration.

[0028] Another embodiment of the present invention provides a freeze concentration method, comprising the following steps: S1, freezing the dilute solution to obtain a solid-liquid mixture; S2, crushing the solid-liquid mixture obtained by freezing and performing solid-liquid separation, using dry gas as an energy medium to penetrate the crushed solid and transfer heat, and retaining solutions in sections to obtain solutions of different concentrations; S3. The solution that meets the target concentration is transferred to the next stage; for the solution that does not meet the target concentration, steps S1-S2 are repeated to continue to increase the solution concentration.

[0029] Another embodiment of the present invention provides a freeze concentration method, comprising the following steps: S1, freezing the dilute solution to obtain a solid-liquid mixture; S2, performing solid-liquid separation on the solid-liquid mixture, crushing the solid after solid-liquid separation to obtain crushed solid, using dry gas as energy medium to penetrate the crushed solid and transfer heat, and retaining solutions in sections to obtain solutions of different concentrations; S3. The solution that meets the target concentration is transferred to the next stage; for the solution that does not meet the target concentration, steps S1-S2 are repeated to continue to increase the solution concentration.

[0030] In one embodiment of the present invention, the drying gas is air or nitrogen. The drying gas can be recycled after being treated. The gas circulation diagram can be, for example, as shown in Figure 1 As shown, the gas forms a gas circulation loop between the dissolving device 1, the gas drying device 2, the gas temperature regulating device 3, and the fan 4; the energy medium gas is continuously dried, temperature-regulated, and heated and dissolved in the circulation loop. The gas drying device 2 is a condensing device, and a condensate 6 (containing a small amount of beneficial substances) will be obtained in the gas drying device 2; the gas temperature regulating device 3 is a heat exchange device. The reasonable combination of the two can utilize the refrigerant and waste heat of the refrigeration equipment to save energy. The broken solid is dissolved by heat, and the solution 5 is retained in sections to obtain solutions of different concentrations, thereby achieving the concentration of the dilute solution.

[0031] When the method of the present invention is used, the energy medium gas (such as nitrogen, air, etc.) is treated in the gas drying device 2 to obtain a dry energy medium gas. The dry energy medium gas is heated to the required temperature in the gas temperature regulating device 3, and then sent to the dissolving device 1 through the fan 4. When the dry energy medium gas penetrates the broken solid in the dissolving device 1 (the broken solid is obtained by freezing the dilute solution to obtain a solid or a solid-liquid mixture, breaking the frozen solid or solid-liquid mixture, or separating the solid-liquid mixture and then breaking the solid), the broken solid is heated and dissolved. After that, the gas leaves the dissolving device 1 and enters the gas drying device 2, and enters the next cycle in the circulation loop: drying, adjusting the temperature, and heating and dissolving the broken solid. The solution 5 is received in sections to obtain solutions of different concentrations. The solution that meets the target concentration is transferred to the next link; the solution that does not meet the target concentration is repeatedly used to increase the solution concentration.

[0032] The present invention adopts a method in which dry gas is used as an energy medium and is made to penetrate crushed solids to transfer heat, thereby solving the problem that irregular arrangement (stacking) of crushed ice particles between crushed solid particles and gaps (including air in the gaps) between crushed solid particles adversely affect heat conduction or radiation, and further improves the effect and efficiency of freeze concentration.

[0033] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A freeze concentration method, characterized in that: The steps include: S1, freezing the dilute solution to obtain a solid; S2, crushing the frozen solid, using dry gas as an energy medium to penetrate the crushed solid and transfer heat, and collecting solutions in sections to obtain solutions of different concentrations; S3. The solution that meets the target concentration is transferred to the next stage; for the solution that does not meet the target concentration, steps S1-S2 are repeated to continue to increase the solution concentration.

2. A freeze concentration method, characterized in that: The steps include: S1, freezing the dilute solution to obtain a solid-liquid mixture; S2, crushing the solid-liquid mixture obtained by freezing and performing solid-liquid separation, using dry gas as an energy medium to penetrate the crushed solid and transfer heat, and retaining solutions in sections to obtain solutions of different concentrations; S3. The solution that meets the target concentration is transferred to the next stage; for the solution that does not meet the target concentration, steps S1-S2 are repeated to continue to increase the solution concentration.

3. A freeze concentration method, characterized in that: The steps include: S1, freezing the dilute solution to obtain a solid-liquid mixture; S2, performing solid-liquid separation on the solid-liquid mixture, crushing the solid after solid-liquid separation to obtain crushed solid, using dry gas as energy medium to penetrate the crushed solid and transfer heat, and retaining solutions in sections to obtain solutions of different concentrations; S3. The solution that meets the target concentration is transferred to the next stage; for the solution that does not meet the target concentration, steps S1-S2 are repeated to continue to increase the solution concentration.

4. The freeze concentration method according to any one of claims 1 to 3, characterized in that: The drying gas is air or nitrogen, or other gases that do not affect and interfere with the dissolution of solids in dilute solutions.

5. The freeze concentration method according to any one of claims 1 to 3, characterized in that: The dry gas can be recycled after treatment.

6. Application of the freeze concentration method according to any one of claims 1 to 5 in the fields of food, cosmetics, biomedicine, petrochemical industry and environmental protection treatment.

7. Application of the freeze concentration method according to any one of claims 1 to 5 in the fields of milk, wine, vinegar, beverages, chemical liquids, Chinese herbal medicine liquids, plant extracts, petroleum purification, chemical purification, seawater purification, and wastewater treatment.

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