Freeze concentration method

Abstract

The invention belongs to the technical field of freeze concentration, and particularly relates to a freeze concentration method, which comprises the following steps: freezing a dilute solution into a solid or solid-liquid mixed frozen material, using gas as an energy medium, and enabling the gas to pass through the frozen material through negative pressure or positive pressure by utilizing the solid structure characteristics of the surface and the interior of the frozen material; the heat transfer of the frozen material is realized; dissolving and separating, and staged taking the solution to obtain solutions with different concentrations; the solution meeting the target concentration is transferred to the next link; the method is repeatedly used for the solution which does not meet the target concentration, and the concentration of the solution continues to be increased. 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, metal treatment, environmental protection 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] The existing freeze concentration technology method is: using the solid-liquid phase relationship between a dilute solution and ice below the freezing point to achieve concentration through solid-liquid separation; this method mainly has two methods: suspension crystallization freeze concentration method and (interface) progressive freeze concentration method. In addition, there is a freeze concentration method that uses the natural dissolution of ice or heating to dissolve the ice (belonging to the traditional conventional heating and dissolving freeze concentration method). However, these three types of existing freeze concentration methods all have the problem of low concentration efficiency.

[0003] Suspended crystallization freeze concentration and progressive freeze concentration are methods of achieving concentration by separating solid and liquid (ice crystals and liquid). Both methods have the problem of ice crystals entraining solutes and low concentration efficiency. Although the traditional conventional heating and dissolving (including natural dissolution) concentration method for frozen materials does not have the efficiency problem caused by solute entrainment, it has to face a problem that technicians have been unable to solve for a long time and seriously affects the concentration efficiency: when the frozen materials are heated in the traditional conventional way, if the heating is too fast, the concentration effect will deteriorate. If low-temperature heating (such as refrigeration temperature) is used, the concentration effect will be better than that at high temperature (relative to the temperature), but it takes a very long time. For this reason, when technicians use the traditional conventional heating and dissolving freeze concentration method, they generally prefer natural dissolution at room temperature (heating and dissolving using environmental energy) or heating and dissolving at refrigeration temperature; the traditional conventional heating and dissolving (including natural dissolution at room temperature) freeze concentration is not only time-consuming, but also has a lower concentration efficiency than the first two methods (methods of achieving concentration through solid-liquid separation). Therefore, most of the current mainstream freeze concentration technology methods use the first two methods (methods of achieving concentration through solid-liquid separation).

[0004] The freeze concentration method recorded in the prior art is: freezing a dilute solution to obtain a solid or a solid-liquid mixture, crushing the frozen solid or solid-liquid mixture or separating the solid-liquid mixture first and then crushing the solid, using dry gas as an energy medium to penetrate the crushed solid and transfer heat, and retaining the solution in sections to achieve freeze concentration of the dilute solution. This method improves the effect and efficiency of dissolution and separation by crushing the frozen material (solid or solid-liquid mixture) and allowing the gas as an energy medium to penetrate the crushed frozen material, thereby improving the effect and efficiency of freeze concentration. However, in the freeze concentration process, before the frozen material is dissolved and separated, a special crushing device needs to be additionally set up to structurally crush the frozen material, which increases the difficulty of operation of the freeze concentration method. For example, the frozen material in a low temperature state (even deep low temperature when the concentration is high) is equivalent to a condensing device for the air in the environment, which will quickly absorb water vapor in the air, and the contact area between the crushed frozen material and the air is increased. At the same time, the heat energy in the air will also cause interference; therefore, this method needs to control the connection environment of the crushing and dissolving links to avoid affecting the freeze concentration efficiency. Under low temperature conditions (especially under deep low temperature conditions), each additional link will increase the complexity and difficulty of the operation, and the increase in operating links will also lead to complexity and difficulty in performing multi-stage cryoconcentration combinations. Summary of the invention

[0005] 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 uses gas as an energy medium, utilizes the solid structure characteristics of the surface and interior of the freezing material, and uses negative pressure or positive pressure to allow the gas to pass through the freezing material for heat transfer, thereby reducing the complexity and difficulty of the prior art freeze concentration, improving the efficiency of freeze concentration, and making the operation easier.

[0006] According to one aspect of the present invention, the present invention provides the following technical solution: A freezing concentration method freezes a dilute solution into a solid or solid-liquid mixed frozen material, uses gas as an energy medium, utilizes the solid structure characteristics of the surface and interior of the frozen material, and allows the gas to pass through the frozen material through negative pressure or positive pressure to achieve heat transfer to the frozen material; through dissolution and separation, the solution is retained in sections to obtain solutions of different concentrations; the solution that meets the target concentration is transferred to the next link; for the solution that does not meet the target concentration, this method is repeated to continue to increase the solution concentration.

[0007] As a preferred embodiment of the freeze concentration method described in the present invention, when a dilute solution is frozen, a dense solid layer is not formed on the surface of the freezing material in the gas inlet and outlet direction, or the density of the solid layer on the surface of the freezing material in the gas inlet and outlet direction is smaller than the density of the solid layer on the surface in other directions, or the dense solid layer formed on the surface of the freezing material in the gas inlet and outlet direction is thinner than the dense solid layer formed on the surface in other directions, and the internal structural characteristics of the freezing material are used to allow the gas to pass through the freezing material. For example, during freezing, the heat transfer direction is controlled to be perpendicular to the gas inlet and outlet direction, so that the surface of the freezing material in the gas inlet and outlet direction does not form a dense solid layer; the way to control the heat transfer direction includes but is not limited to: selecting an appropriate cold source orientation and a combined design of the freezing device to achieve it. For another example, a material with a small thermal conductivity is selected in the gas inlet and outlet direction of the freezing device to limit the heat transfer in this direction, so that the solid layer formed on the surface of the freezing material in this direction is thinner and less dense.

[0008] As a preferred embodiment of the freeze concentration method described in the present invention, the surface solid layer of the freezing material in the gas inlet and outlet direction is fractured by the gas pressure difference, and then the gas pressure is adjusted and the solution is extracted by negative pressure or positive pressure. During the extraction process, the energy medium gas passes through the freezing material to transfer heat to it.

[0009] As a preferred embodiment of the freeze concentration method described in the present invention, the surface solid layer of the freezing material in the gas inlet and outlet direction is fractured by the pressure difference of the gas, specifically: the pressure difference is formed by introducing high-pressure gas to fracture the surface solid layer of the freezing material in the gas inlet and outlet direction, or the pressure difference is formed by negative pressure extraction to fracture the surface solid layer of the freezing material in the gas inlet and outlet direction.

[0010] As a preferred embodiment of the freeze concentration method described in the present invention, the dense solid layer on the surface of the frozen material in the gas inlet and outlet direction is mechanically destroyed, and the internal structural characteristics of the frozen material are utilized to allow the gas to pass through the frozen material and transfer heat to it.

[0011] As a preferred embodiment of the freeze concentration method described in the present invention, a channel is provided in the freezing material to allow gas to pass through the freezing material to transfer heat thereto.

[0012] As a preferred embodiment of the freeze concentration method of the present invention, the gas channel and the solution channel are preset during freezing; or the gas channel and the solution channel are arranged on the frozen material after freezing.

[0013] As a preferred solution of the freeze concentration method described in the present invention, the gas channel and the solution channel are arranged as the same channel, or different gas channels and solution channels are arranged independently.

[0014] As a preferred embodiment of the freeze concentration method described in the present invention, the gas used as the energy medium is a gas that does not interfere with the dissolution and separation of the frozen material, such as air, inert gas, carbon dioxide, nitrogen, etc.

[0015] As a preferred embodiment of the freeze concentration method described in the present invention, the energy carried by the energy medium gas is used to transfer heat to the frozen material, and the energy medium gas is replenished with energy for recycling; or the air energy carried by the air itself is used to transfer heat to the frozen material; before the energy medium gas transfers heat to the frozen material, it can be dried as needed.

[0016] According to another aspect of the present invention, the present invention provides the following technical solution: The invention discloses an application of the freeze concentration method in the fields of food, cosmetics, biomedicine, petrochemical industry, metal processing, environmental protection processing, etc.

[0017] 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, metal separation and purification, seawater purification, wastewater treatment, etc.

[0018] An application of the above freeze concentration method in the field of freeze concentration and separation and purification of heat-sensitive raw materials.

[0019] 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, beverages (such as juice, coffee, tea, soy milk, soy milk, etc.), chemical liquids, Chinese herbal medicine liquids, plant extracts, petroleum purification, chemical purification, metal separation and purification, seawater purification, wastewater treatment, etc.

[0020] The beneficial effects of the present invention are as follows: The present invention proposes a freeze concentration method, which freezes a dilute solution into a solid or solid-liquid mixed frozen material, uses gas as an energy medium, utilizes the solid structure characteristics of the surface and interior of the frozen material, and allows the gas to pass through the frozen material through negative pressure or positive pressure to achieve heat transfer to the frozen material; through dissolution and separation, the solution is retained 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 continue to increase the solution concentration. This method does not require the additional setting of a special crushing device to structurally crush the frozen material before dissolving and separating the frozen material, making the freeze concentration process and operation simpler, improving the effect and efficiency of freeze concentration, and facilitating application in the fields of food, cosmetics, biomedicine, petrochemicals, metal processing, environmental protection processing, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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.

[0022] Figure 1 The process flow chart of the freeze concentration method of the present invention is shown in FIG.

[0023] 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

[0024] 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.

[0025] like Figure 1 As shown, the present invention provides a freezing concentration method, which freezes a dilute solution into a solid or solid-liquid mixed frozen material, uses gas as an energy medium, utilizes the solid structure characteristics of the surface and interior of the frozen material, and allows the gas to pass through the frozen material through negative pressure or positive pressure to achieve heat transfer to the frozen material; through dissolution and separation, the solution is retained in sections to obtain solutions of different concentrations; the solution that meets the target concentration is transferred to the next link; for the solution that does not meet the target concentration, this method is repeated to continue to increase the solution concentration.

[0026] In one embodiment of the present invention, when a dilute solution is frozen, a dense solid layer is not formed on the surface of the freezing material in the direction of gas inlet and outlet, or the density of the solid layer on the surface in the direction of gas inlet and outlet of the freezing material is smaller than the density of the solid layer on the surface in other directions, or the dense solid layer formed on the surface of the freezing material in the direction of gas inlet and outlet is thinner than the dense solid layer formed on the surface in other directions, and the internal structural characteristics of the freezing material are utilized to allow the gas to pass through the freezing material.

[0027] In the specific implementation of the present invention, there are a variety of preferred methods to choose from in order to allow the gas to pass through the frozen material: (1) The solid layer on the surface of the frozen material in the direction of gas inlet and outlet is fractured by the pressure difference of the gas, and then the solution is extracted by negative pressure or positive pressure after adjusting the gas pressure. During the extraction process, the energy medium gas passes through the frozen material to transfer heat to it. The solid layer on the surface of the frozen material in the direction of gas inlet and outlet is fractured by the pressure difference of the gas: the solid layer on the surface of the frozen material in the direction of gas inlet and outlet is fractured by forming a pressure difference by introducing high-pressure gas, or the solid layer on the surface of the frozen material in the direction of gas inlet and outlet is fractured by forming a pressure difference by negative pressure extraction.

[0028] (2) Mechanically destroying the dense solid layer on the surface of the frozen material in the direction of gas inlet and outlet, and utilizing the internal structural characteristics of the frozen material to allow the gas to pass through the frozen material, or setting a channel in the frozen material to allow the gas to pass through the frozen material and transfer heat to it.

[0029] (3) A channel is provided in the frozen material to allow gas to pass through the frozen material and transfer heat thereto; preferably, a gas channel and a solution channel are preset during freezing; or a gas channel and a solution channel are provided on the frozen material after freezing. Further preferably, the gas channel and the solution channel are provided as the same channel, or different gas channels and solution channels are provided independently.

[0030] In one embodiment of the present invention, the gas used as the energy medium is a gas that does not interfere with the dissolution and separation of the frozen material, for example, it may be air, an inert gas, carbon dioxide gas, nitrogen gas, etc.

[0031] In one embodiment of the present invention, the energy carried by the energy medium gas is used to transfer heat to the frozen material, and the energy medium gas is replenished with energy for recycling; or the air energy carried by the air itself is used to transfer heat to the frozen material; before the energy medium gas transfers heat to the frozen material, it can be dried as needed.

[0032] 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: Freeze the dilute solution into a solid or solid-liquid mixed frozen material, use gas as the energy medium, utilize the solid structure characteristics of the surface and interior of the frozen material, and pass the gas through the frozen material through negative or positive pressure to achieve heat transfer to the frozen material; through dissolution and separation, retain the dissolved solution in sections to obtain solutions of different concentrations.

2. The freeze concentration method according to claim 1, characterized in that When a dilute solution is frozen, no dense solid layer is formed on the surface of the freezing material in the direction of gas entry and exit, or the density of the solid layer on the surface of the freezing material in the direction of gas entry and exit is smaller than the density of the solid layer on the surface in other directions, or the dense solid layer formed on the surface of the freezing material in the direction of gas entry and exit is thinner than the dense solid layer formed on the surface in other directions, and the internal structural characteristics of the freezing material are utilized to allow the gas to pass through the freezing material.

3. The freeze concentration method according to claim 1, characterized in that The surface solid layer of the freezing material in the gas inlet and outlet direction is fractured by the gas pressure difference, and then the gas pressure is adjusted and the solution is extracted by negative pressure or positive pressure. During the extraction process, the energy medium gas passes through the freezing material to transfer heat to it.

4. The freeze concentration method according to claim 1, characterized in that The dense solid layer on the surface of the frozen material in the direction of gas inlet and outlet is destroyed mechanically, and the internal structural characteristics of the frozen material are used to allow the gas to pass through the frozen material and transfer heat to it.

5. The freeze concentration method according to claim 1, characterized in that Channels are provided in the cryogenic material to allow gas to pass through the cryogenic material to transfer heat thereto.

6. The freeze concentration method according to claim 5, characterized in that The gas channel and the solution channel are preset during freezing; or the gas channel and the solution channel are set on the frozen material after freezing.

7. The freeze concentration method according to claim 6, characterized in that The gas channel and the solution channel are arranged as the same channel, or different gas channels and solution channels are arranged independently.

8. The freeze concentration method according to claim 1, characterized in that: The gas used as the energy medium is a gas that does not interfere with the dissolution and separation of the cryogenic material.

9. The freeze concentration method according to claim 1, characterized in that: The energy carried by the energy medium gas is used to transfer heat to the freezing material, and the energy medium gas is replenished and recycled; or the air energy carried by the air itself is used to transfer heat to the freezing material.

10. Application of the freeze concentration method according to any one of claims 1 to 9 in the fields of food, cosmetics, biomedicine, petrochemicals, metal processing, and environmental protection processing.

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