Method for reducing solute loss caused by ice crystal entrainment

Abstract

The present invention relates to the technical field of freeze concentration, and in particular to a method for reducing solute loss caused by ice crystal entrainment. By using the negative correlation between a solute concentration and a melting point, ice crystals are fed into a dissolution device, and heat is transferred to the ice crystals for dissolution; solutions are collected in fractions to obtain solutions of different concentrations, and solutes entrained in the ice crystals are recovered. A solute recovery method of the present invention has low requirements for ice crystals, and can simplify the complex control of ice crystal formation and growth in existing freeze concentration methods. Additionally, the method omits an operation step of ice crystal washing in existing freeze concentration methods, thereby simplifying devices and operation steps, and making the devices and operations simpler.

Description

A method to reduce solute loss caused by ice crystal entrainment Technical Field

[0001] This invention belongs to the field of freeze concentration technology, specifically a method for reducing solute loss caused by ice crystal entrainment. Background Technology

[0002] The commonly used principle (physical principle) in existing freeze concentration technologies is to remove water from the solution in a solid state, utilizing the solid-liquid phase equilibrium between ice and aqueous solution. The main methods are suspension crystallization freeze concentration and progressive freeze concentration. The principle of suspension crystallization freeze concentration is to continuously remove small free ice crystals suspended in the liquid during freezing of a dilute solution, thereby increasing the liquid concentration. The principle of progressive freeze concentration is that as ice forms and grows on the cooling surface during freezing of a dilute solution, solute near the solid-liquid interface is removed to the liquid phase, leading to a gradual increase in the solute concentration in the liquid phase. In the freeze concentration process of these methods, the effectiveness of ice crystal separation and the control of solute loss caused by ice crystal entrainment are extremely important for the success of freeze concentration applications. This is also one of the reasons why existing freeze concentration equipment has a complex structure, high cost, and complicated operation.

[0003] In suspension crystallization freeze concentration, complex processes and equipment are involved to reduce solute entrainment in ice crystal formation (cultivation), filtration, and ice washing. In progressive freeze concentration, a slower freezing rate and longer time are required to minimize solute entrainment in ice crystals; however, solute loss due to ice crystal entrainment remains unavoidable. We know that due to the limitations of physical principles, freeze concentration methods that utilize the solid-liquid phase equilibrium between ice and aqueous solution to remove water from the solution in a solid state inevitably suffer from solute loss due to ice crystal entrainment.

[0004] To address the unavoidable solute loss caused by ice crystal entrainment, the ice (crystals) produced by the freeze-concentration method (utilizing the solid-liquid phase relationship) is heated and dissolved during production. The resulting melt (solution) is then used for other purposes (because the ice solution contains solute entrainment), such as adjusting the concentration or using it as a flavoring supplement for other products (the presence of entrained solutes and flavor substances is more advantageous than using pure water).

[0005] Under conventional heating methods, ice dissolution takes a long time, and the concentration difference between the received solutions in each stage is small, resulting in very low solute recovery efficiency. This is because: in progressive freeze-thaw concentration, the ice layer formed and grown on the cooling surface is a dense ice (crystal) body with low solute content, and its solid structure hinders heat transfer and the dissolution and separation of entrained solute. In suspension crystallization freeze-thaw concentration, if pressure is used for solid-liquid separation and small ice crystals are formed into block ice bodies, the solid structure of these block ice bodies also hinders the dissolution and separation of entrained solute. Under conventional heating methods, recovery through heating and dissolution is time-consuming; moreover, during the recovery process, the concentration difference between the recovered solutions in each stage is not large enough, resulting in low recovery efficiency. In other words, conventional heating methods also struggle to effectively distinguish between different stages of solute, thus hindering high-efficiency solute recovery. This is why, when using existing freeze-concentration techniques, even though it is known that solute entrainment exists in the ice crystals after solid-liquid separation, producers prefer to use the melt (solution) formed by heating the ice as a production formulation material or a raw material for other purposes, rather than adding a heating and dissolving method for solute recovery during the freeze-concentration process: it is time-consuming, ineffective, and inefficient.

[0006] The aforementioned existing freeze concentration methods suffer from problems such as concentration efficiency and solute entrainment, which are extremely important for the successful application of freeze concentration. These problems are also one of the reasons why existing freeze concentration equipment has a complex structure, high cost, and complicated operation. Summary of the Invention

[0007] To address the problems existing in the prior art, the main objective of this invention is to propose a method for reducing solute loss caused by ice crystal entrainment.

[0008] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0009] A method for reducing solute loss caused by ice crystal entrainment is characterized by utilizing the negative correlation between solute concentration and melting point. Ice crystals generated during existing freeze-concentration processes are fed into a dissolving device, where heat is transferred to dissolve them. The solution is then collected in stages to obtain solutions of different concentrations, thus recovering the solute entrained by the ice crystals. This solute recovery method has lower requirements for ice crystals, simplifying the complex control of ice crystal generation and cultivation in existing freeze-concentration methods. Furthermore, this method eliminates the ice crystal washing step in existing freeze-concentration methods, thereby simplifying equipment and operations.

[0010] As a preferred embodiment of the method for reducing solute loss caused by ice crystal entrainment according to the present invention, the generated ice crystals may include ice crystals generated during various freeze-concentration processes, such as suspension crystallization freeze-concentration and progressive freeze-concentration methods.

[0011] As a preferred embodiment of the method for reducing solute loss caused by ice crystal entrainment according to the present invention, the ice crystals generated in the progressive freeze-concentration method need to be broken up in a way that destructively breaks their solid structure before being sent to the dissolving device; the ice crystals generated in the suspension crystallization freeze-concentration method do not need to be broken up in a way that destructively breaks their solid structure if the ice crystal particles are small and the small ice crystals do not form blocky ice bodies during solid-liquid separation; the ice crystal particles grown in the suspension crystallization freeze-concentration method are too large or the ice crystals form blocky ice bodies during solid-liquid separation (for example, by using pressure to form blocky ice bodies from small ice crystals during solid-liquid separation), and therefore need to be broken up in a way that destructively breaks their solid structure before being sent to the dissolving device.

[0012] As a preferred embodiment of the method for reducing solute loss caused by ice crystal entrainment according to the present invention, wherein: a device for destructively breaking the solid structure of ice crystals is provided in the dissolving device to break the ice crystals and transfer heat to them.

[0013] As a preferred embodiment of the method for reducing solute loss caused by ice crystal entrainment according to the present invention, the solution is separated and flows out during heating and dissolving in the following ways: natural outflow, filtration separation, negative pressure extraction or centrifugal separation.

[0014] As a preferred embodiment of the method for reducing solute loss caused by ice crystal entrainment according to the present invention, the solution that meets the target concentration is transferred to the next stage; the solution that does not meet the target concentration can be mixed with the next batch of raw materials and sent to the freeze concentration device for further freeze concentration, or the solution that does not meet the target concentration can be sent to the freeze dissolution component for freezing, and then the solute can be recovered by dissolution separation.

[0015] To solve the above-mentioned technical problems, according to another aspect of the present invention, the present invention provides the following technical solution:

[0016] The above-mentioned method for reducing solute loss caused by ice crystal entrainment has applications in the fields of food, cosmetics, biomedicine, and environmental treatment.

[0017] The above-mentioned method for reducing solute loss caused by ice crystal entrainment has applications in the fields of milk, wine, beverages (such as juice, coffee, tea, soy milk, etc.), chemical solutions, traditional Chinese medicine solutions, plant extracts, seawater desalination, and wastewater treatment.

[0018] The above-mentioned method for reducing solute loss caused by ice crystal entrainment is applied in the field of freeze concentration and separation purification of heat-sensitive raw materials.

[0019] The above-mentioned method for reducing solute loss caused by ice crystal entrainment has applications in the fields of freeze concentration and separation purification of milk, wine, beverages (such as juice, coffee, tea, soy milk, etc.), chemical liquids, traditional Chinese medicine liquids, plant extracts, seawater desalination, and wastewater treatment.

[0020] The beneficial effects of this invention are as follows:

[0021] This invention proposes a method to reduce solute loss caused by ice crystal entrainment. While progressive freeze-concentration methods require destructive fragmentation of the solid structure of ice crystals, suspension crystallization freeze-concentration methods can avoid this destructive fragmentation if pressure is not used during solid-liquid separation to form larger ice blocks. Heat is transferred to the ice crystals to dissolve them, and the solution is collected in stages to obtain solutions of different concentrations, thus recovering the solute entrained in the ice crystals. This invention reduces the need for washing ice crystals during freeze-concentration in existing methods, simplifying the process and consequently reducing equipment and operational steps. Furthermore, this invention has lower requirements for ice crystals, simplifying the complex control required for ice crystal cultivation in existing methods, making the equipment and operation simpler. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 is a schematic diagram of a preferred process of the method of the present invention.

[0024] Figure 2 is a schematic diagram of another preferred process of the method of the present invention.

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

[0026] The technical solutions described below in conjunction with the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] As shown in Figure 1, a method for reducing solute loss caused by ice crystal entrainment includes:

[0029] Ice crystals produced during the freeze-concentration process require destructive breaking of their solid structure in progressive freeze-concentration methods. However, ice crystals produced in suspension crystallization freeze-concentration methods, if the ice crystals are small and did not form blocky ice masses during solid-liquid separation, do not require destructive breaking of their solid structure. These ice crystals are then fed into a dissolving device where heat is transferred to dissolve them. Segmented solutions of different concentrations are obtained. Solutions meeting the target concentration are mixed with the concentrated solution obtained from freeze-concentration and stored for later use. Solutions not meeting the concentration requirements are sent to a feed liquid tank and mixed with the feed liquid for freeze-concentration. Ice solutions with low solute content are discarded.

[0030] Example 2

[0031] As shown in Figure 2, a method for reducing solute loss caused by ice crystal entrainment includes:

[0032] Ice crystals produced during the freeze-concentration process require destructive breaking of their solid structure in progressive freeze-concentration methods. However, ice crystals produced in suspension crystallization freeze-concentration methods, if the ice crystals are small and did not form blocky ice masses during solid-liquid separation, do not require destructive breaking of their solid structure. These ice crystals are then fed into a dissolving device, where heat is transferred to dissolve them. Solutions of different concentrations are obtained by fractional extraction. Solutions meeting the target concentration are mixed with the concentrated solution obtained from freeze-concentration and stored for later use. Solutions not meeting the target concentration are sent to a freeze-dissolving assembly, where the solution is frozen from a solid state, and heat is transferred to dissolve the ice. Solutions of different concentrations are then collected. Solutions meeting the target concentration are mixed with the concentrated solution obtained from freeze-concentration and stored for later use. Solutions not meeting the target concentration are sent to the freeze-dissolving assembly, where freezing and dissolving separation (multiple freeze-dissolving separations can be used if necessary) is performed to increase the solution concentration and remove ice liquid with low solute content. Alternatively, a solution that has been increased to a higher concentration through a freeze-dissolving component but still does not meet the target concentration requirement can be sent to a raw material tank, mixed with the raw material, and then frozen and concentrated using a freeze-concentrating device.

[0033] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

A method for reducing solute loss caused by ice crystal entrainment, characterized in that, The ice crystals generated during the existing freeze-concentration process are fed into a dissolving device, where heat is transferred to the ice crystals to heat and dissolve them. By collecting solutions in segments to obtain solutions of different concentrations, the solutes entrained in ice crystals can be recovered. The method for reducing solute loss caused by ice crystal entrainment according to claim 1 is characterized in that, Existing freeze concentration processes include suspension crystallization freeze concentration and progressive freeze concentration. The method for reducing solute loss caused by ice crystal entrainment according to claim 2 is characterized in that, Ice crystals produced in the progressive freeze-concentration method need to be broken up in a way that damages their solid structure before being sent to the dissolving device; ice crystals grown in the suspension crystallization freeze-concentration method that are too large or that form blocky ice bodies during solid-liquid separation also need to be broken up in a way that damages their solid structure before being sent to the dissolving device. The method for reducing solute loss caused by ice crystal entrainment according to claim 1 is characterized in that, The dissolving apparatus is equipped with a device that destructively breaks down the solid structure of the ice crystals, thereby breaking them down and transferring heat to them. The method for reducing solute loss caused by ice crystal entrainment according to claim 1 is characterized in that, When heating and dissolving, the solution can be separated and flowed out in the following ways: natural flow, filtration, negative pressure extraction, or centrifugal separation. The method for reducing solute loss caused by ice crystal entrainment according to claim 1 is characterized in that, Solutions that meet the target concentration are transferred to the next stage; solutions that do not meet the target concentration are mixed with the next batch of raw materials and sent to a freeze concentration unit for further freeze concentration, or solutions that do not meet the target concentration are sent to a freeze-dissolution unit for freezing, and then the solute is recovered through dissolution and separation. The application of the method for reducing solute loss caused by ice crystal entrainment as described in any one of claims 1-6 in the fields of food, cosmetics, biomedicine, and environmental treatment. The application of the method for reducing solute loss caused by ice crystal entrainment as described in any one of claims 1-6 in the fields of milk, wine, beverages, chemical solutions, traditional Chinese medicine solutions, plant extracts, seawater desalination, and wastewater treatment.

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