A method and apparatus for freeze concentration

Abstract

This application belongs to the field of cryogenic concentration technology, specifically relating to a cryogenic concentration method and apparatus. The method includes: obtaining a stock solution; freezing the stock solution to obtain a solid ice body; and, during the melting process under the same conditions, identifying a correlation between the maximum cumulative fraction concentration and the solid ice body temperature when the solid ice body temperature reaches a constant level, using this correlation as the basis for fractionation and concentration operations. The method involves monitoring the temperature of the solid ice body, setting the melting temperature based on the correlation, and adjusting and controlling the melting and fractionation processes to achieve precise fractionation and obtain a solution of the target concentration. This application provides a cryogenic concentration method and apparatus that, through precise fractionation of the melted fraction, solves the technical problems of difficulty in determining or defining the segmented retention of the melted fraction in existing cryogenic concentration methods and apparatuses, further improving the effect and efficiency of cryogenic concentration and enhancing the industrial applicability of cryogenic concentration technology.

Description

Technical Field

[0001] This application relates to the field of cryogenic concentration technology, specifically, to a cryogenic concentration method and apparatus. Background Technology

[0002] Existing freeze-concentration techniques utilize the phase equilibrium between a dilute solution and ice below its freezing point to achieve concentration through solid-liquid separation; this method is also known as freeze-de-icing concentration. The solid (solid ice) involved in this solid-liquid separation refers to pure water ice. This method primarily employs two approaches: suspension crystallization freeze-concentration and (interfacial) progressive freeze-concentration. Additionally, there are freeze-concentration methods that utilize the natural dissolution of solid ice or the heating and dissolution of solid ice (belonging to the traditional conventional heating-dissolution freeze-concentration method, also known as block freeze-concentration). However, all three existing freeze-concentration methods suffer from low concentration efficiency.

[0003] Freeze-concentration and progressive freeze-concentration are methods that achieve concentration through solid-liquid (ice crystals and liquid) separation. Both suffer from problems such as solute entrainment by ice crystals and low concentration efficiency. While conventional heating and dissolution (including natural dissolution) methods for concentrating frozen materials do not have the efficiency problem caused by solute entrainment, they face a long-standing and severely inefficient issue: heating frozen materials too quickly degrades concentration, while low-temperature heating (such as at refrigeration temperatures) yields better results but is extremely time-consuming. Therefore, when using conventional heating and dissolution freeze-concentration methods, technicians generally prefer natural dissolution at room temperature (using ambient energy) or heating at refrigeration temperatures. Conventional heating and dissolution (including natural dissolution at room temperature) freeze-concentration is not only time-consuming but also less efficient than the previous two methods (concentration through solid-liquid separation). Therefore, most current mainstream freeze-concentration technologies utilize the former two methods (concentration through solid-liquid separation).

[0004] For solids formed by freezing dilute solutions, existing technologies can achieve efficient and controllable concentration by avoiding or reducing the interference of the solid structure and solute distribution of the freezing system on heat and mass transfer, or by using enhanced heat and mass transfer technologies to melt the solids and extract fractions in stages. Methods to avoid or reduce the interference of the solid structure and solute distribution of the freezing system on heat and mass transfer include: setting flow channels on the freezing material, placing heat sources in specific locations, breaking up the freezing material, preventing the formation of dense ice layers or reducing the density of ice layers in the direction of fraction outflow, using gas as an energy medium to penetrate the freezing material and transfer heat, and new multi-stage concentration systems for freezing concentration. Although these methods achieve efficient and controllable freezing concentration, they all require fractional extraction of the melt fraction for concentration. The accuracy of the fractionation operation steps (fractional extraction of the melt fraction) and the fractionation method directly affect the concentration efficiency. Further improving the concentration efficiency and accuracy of freezing concentration is a technical problem that needs to be solved. Therefore, there is an urgent need for a method and basis for achieving precise fractionation to further improve the effect and efficiency of freezing concentration. Summary of the Invention

[0005] To address the aforementioned technical issues, this application research has discovered a correlation between the temperature of the solid ice during the melting process and the concentration of the maximum cumulative fraction: When the temperature of the solid ice, formed by freezing a dilute solution, reaches a constant, the maximum amount of cumulative fraction that can be received (referred to as the maximum cumulative fraction) is constant, and the concentration of the maximum cumulative fraction is also constant. When a solute-containing liquid is frozen into solid ice, a correlation exists between the temperature of the solid ice and the concentration of the maximum cumulative fraction during the melting process. Specifically, under the same melting conditions, when the temperature of the solid ice is constant, the maximum cumulative fraction (called the maximum cumulative fraction) that can be obtained by fractionation from the solid ice is constant, and the concentration of the maximum cumulative fraction is also constant. The principle behind this correlation is as follows: When a solute-containing liquid is frozen into solid ice (note: this solid ice is not pure water ice, but a solid material with uneven solute distribution), during the melting process, when the temperature of the solid ice reaches a constant value, the temperature of the last fraction separated from the maximum cumulative fraction is the same as the temperature of the solid ice. During the melting process, the solid ice forms a solid-liquid mixture, and the solid temperature and liquid temperature in the solid-liquid mixture are the same. These temperatures and concentrations have a correlation. Therefore, the concentration of the maximum cumulative fraction can be predicted by detecting the temperature of the solid ice, providing a new path and direction for the research and exploration of precise fractionation technology for melted distillates. It is evident that by setting up a system for detecting the temperature of solid ice, rapid, objective, and reliable concentration detection can be achieved. This detection method provides a new path and direction for technical research and exploration to address the issue of rapidly and accurately defining the fractionation operation steps (fractional collection of melt fractions) during the melting process.

[0006] This application provides a freeze concentration method, comprising: obtaining a stock solution; freezing the stock solution to obtain a solid ice body; and, during the melting process under the same conditions, establishing a correspondence between the maximum cumulative distillate concentration and the solid ice body temperature when the solid ice body temperature reaches a constant, using this correspondence as the basis for fractionation and concentration operations. Specifically, for a solid ice body frozen from a dilute solution, during the melting process under the same conditions, when the solid ice body temperature reaches a constant, the maximum amount of cumulative distillate that can be received, or the maximum cumulative distillate, is constant, and the concentration of the maximum cumulative distillate is constant. The method involves monitoring the temperature of the solid ice body, setting the melting temperature based on the correspondence, and adjusting and controlling the melting and fractionation processes to achieve precise fractionation and obtain a solution of the target concentration.

[0007] In a preferred embodiment of the freeze concentration method described in this application, the freezing is carried out in a freezing component, which realizes the transformation of the stock solution into solid ice; the melting is carried out in a melting component, which, according to the corresponding relationship, realizes the melting of the solid ice under corresponding constant temperature conditions to obtain the corresponding maximum cumulative fraction.

[0008] As a preferred embodiment of the freeze concentration method described in this application, the fractionation is carried out in a fractionation assembly, which, according to the corresponding relationship, fractionates the corresponding maximum cumulative fraction obtained from melting under corresponding constant temperature conditions to obtain a solution of the corresponding concentration; the monitoring, setting, and adjustment control are carried out in a control system, which realizes the automated freeze concentration of the stock solution through an automatic control program device.

[0009] As a preferred embodiment of the freeze concentration method described in this application, according to the corresponding relationship, when the temperature of the solid ice reaches a constant during the melting process, the temperature of the last fraction separated in the maximum cumulative fraction is the same as the temperature of the solid ice; the solid ice forms a solid-liquid mixture during the melting process, and the solid temperature and liquid temperature in the solid-liquid mixture are the same.

[0010] This application also provides a cryogenic concentration apparatus for implementing the above-described cryogenic concentration method. The apparatus includes: a freezing component, a melting component, a fractionation component, and a control system. The stock solution is converted into solid ice by the freezing component. Under the monitoring of the control system, the temperature of the solid ice is measured. The control system adjusts the melting component to melt the solid ice and adjusts the fractionation component to fractionate the fraction obtained from the melting of the solid ice to obtain a solution of the corresponding concentration, thus completing the concentration of the stock solution.

[0011] As a preferred embodiment of the cryogenic concentration apparatus described in this application, the cryogenic assembly includes: a cryogenic mechanism and a liquid adsorption mechanism; wherein, the cryogenic surface of the cryogenic mechanism can be a plane, or the surface or inner side of a cylinder, or the surface or inner side of a sphere; the liquid adsorption mechanism forms a liquid film on the cryogenic surface in a manner including but not limited to: allowing the liquid to adhere to the cryogenic surface and form a liquid film layer by spraying, sprinkling, or gravity flow.

[0012] As a preferred embodiment of the cryogenic concentration apparatus described in this application, the melting component includes: an ice scraping device, a solid ice collection device, and a melting device; wherein, the ice scraping method of the ice scraping device includes: keeping the scraping device stationary while the frozen surface moves, or keeping the frozen surface stationary while the scraping device moves, or both move but there is a displacement difference; the movement mode includes: rotation, planar displacement causing a displacement difference between the frozen surface and the scraping device.

[0013] As a preferred embodiment of the cryogenic concentration apparatus described in this application, the melting component includes: an enhanced heat transfer component and a melting enhanced mass transfer component; the enhanced heat transfer component includes: a crushing device and a heat exchange device; the heat exchange device includes: a partition type, a mixing type, or a regenerative type; the melting enhanced mass transfer component includes: a heating mechanism and an enhanced mass transfer device; the heating method of the heating mechanism includes: using conduction, radiation, or an energy medium to penetrate and crush ice; the enhanced mass transfer method of the enhanced mass transfer device includes: using centrifugal separation or negative pressure extraction.

[0014] As a preferred embodiment of the cryogenic concentration apparatus described in this application, an automatic control program device is installed in the control system to achieve automated cryogenic concentration.

[0015] This application also provides an application of the above-mentioned freeze concentration method or freeze concentration apparatus in the fields of food, cosmetics, biopharmaceuticals, petrochemicals, metal processing, and environmental protection.

[0016] The beneficial effects of this application are as follows: This application provides a freeze concentration method that solves the technical problems in existing freeze concentration methods and apparatus, such as the difficulty in determining or defining the fractionation operation steps (fractional retention of melt fraction), by accurately fractionating the melted fraction. This further improves the effect and efficiency of freeze concentration and enhances the industrial applicability of freeze concentration technology. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application 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 this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the automated, continuously operating cryogenic concentration apparatus in Embodiment 1 of this application; Figure 2 This is a schematic diagram of the automated, continuously operating cryogenic concentration apparatus in Embodiment 2 of this application.

[0019] Figure label: 101-Solid tank 1, 102-Liquid adsorption mechanism, 103-Freezing mechanism, 104-Liquid film, 105-Ice layer 1, 106-Refrigerator, 107-Freezing surface, 108-Rotating shaft, 109-Ice layer scraping device, 110-Solid ice collection device, 111-Melting device, 112-Control system 1, 113-Collection tank for near-pure water (extremely low concentration) solution, 114-Collection tank for solution meeting target concentration, 115, 116-Collection tanks for solutions of different concentrations, 117, 118, 119, 120, 121, 122, 123-Gate valve 1; 201-Solid Tank II, 202-Refrigeration Components, 203-Crushing Device, 204-Heat Exchange Device, 205-Insulated Storage Tank, 206, 219-Transfer Pumps, 207-Heating Mechanism, 208-Top Cover, 209, 216-Motor, 210-Energy Medium Gas Inlet, 211-Ice Layer Thickness Sensor, 212-Rotating Basket, 213-Paper Spreading Device, 214-Insulated Protective Jacket, 215-Gas-Liquid Outlet, 217-Gas-Liquid Separator, 218-Gas Heater, 220-Control System II, 221, 222, 223, 224-Collection Tanks, 227-Solid Ice Temperature Detector, 225, 226, 228, 229, 230, 231, 232, 233, 234, 235-Gate Valve II, 236-Bearing, 237-Base, 238-Ice Layer II.

[0020] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions in the embodiments will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] This application provides a freeze concentration method, comprising: obtaining a stock solution; freezing the stock solution to obtain a solid ice body; and, during the melting process under the same conditions, establishing a correspondence between the maximum cumulative distillate concentration and the solid ice body temperature when the solid ice body temperature reaches a constant, using this correspondence as the basis for fractionation and concentration operations. Specifically, for a solid ice body frozen from a dilute solution, during the melting process under the same conditions, when the solid ice body temperature reaches a constant, the maximum amount of cumulative distillate that can be received, or the maximum cumulative distillate, is constant, and the concentration of the maximum cumulative distillate is constant. The method involves monitoring the temperature of the solid ice body, setting the melting temperature based on the correspondence, and adjusting and controlling the melting and fractionation processes to achieve precise fractionation and obtain a solution of the target concentration.

[0023] The freezing is carried out in a freezing component, which realizes the transformation of the original liquid into solid ice; the melting is carried out in a melting component, which, according to the corresponding relationship, realizes the melting of the solid ice under the corresponding constant temperature conditions to obtain the corresponding maximum cumulative fraction.

[0024] The fractionation is carried out in a fractionation assembly, which, according to the corresponding relationship, fractionates the corresponding maximum cumulative fraction obtained from melting under corresponding constant temperature conditions to obtain a solution of the corresponding concentration. The monitoring, setting, and adjustment control are carried out in a control system, which realizes the automated freezing and concentration of the stock solution through an automatic control program device.

[0025] According to the aforementioned correspondence, when the temperature of the solid ice reaches a constant during the melting process, the temperature of the last fraction separated in the maximum cumulative fraction is the same as the temperature of the solid ice; the solid ice forms a solid-liquid mixture during the melting process, and the solid temperature and liquid temperature in the solid-liquid mixture are the same.

[0026] This application also provides an apparatus for implementing the above-described freeze concentration method, comprising: a freezing component, a melting component, a fractionation component, and a control system; the stock solution is converted into solid ice through the freezing component; under the monitoring of the control system, the temperature of the solid ice is measured; the control system adjusts the melting component to melt the solid ice; and adjusts the fractionation component to fractionate the fraction obtained from the melting of the solid ice to obtain a solution of the corresponding concentration, thereby completing the concentration of the stock solution.

[0027] The freezing assembly includes: a freezing mechanism and a liquid adhesion mechanism; wherein, the freezing surface of the freezing mechanism can be a plane, or the surface or inner side of a cylinder, or the surface or inner side of a sphere; the liquid adhesion mechanism forms a liquid film on the freezing surface in a manner including but not limited to: allowing the liquid to adhere to the freezing surface and form a liquid film layer by spraying, sprinkling, or gravity flow.

[0028] The melting component includes: an ice scraping device, a solid ice collection device, and a melting device; wherein, the ice scraping method of the ice scraping device includes: keeping the scraping device stationary while the frozen surface moves, or keeping the frozen surface stationary while the scraping device moves, or both move but there is a displacement difference; the movement method includes: rotation, planar displacement causing a displacement difference between the frozen surface and the scraping device.

[0029] The melting component includes: an enhanced heat transfer component and a melting enhanced mass transfer component; the enhanced heat transfer component includes: a crushing device and a heat exchange device; the heat exchange form of the heat exchange device includes: a partition type, a mixing type, or a regenerative type; the melting enhanced mass transfer component includes: a heating mechanism and an enhanced mass transfer device; the heating method of the heating mechanism includes: using conduction, radiation, or an energy medium to penetrate and crush ice; the enhanced mass transfer method of the enhanced mass transfer device includes: using centrifugal separation or negative pressure extraction.

[0030] An automatic control program device is installed in the control system to achieve automated freeze concentration.

[0031] This application also provides an application of the above-mentioned freeze concentration method or apparatus in the fields of food, cosmetics, biopharmaceuticals, petrochemicals, metal processing, and environmental protection. Specifically, the above-mentioned freeze concentration method or apparatus is applied in the fields of milk, vinegar (including vinegar-containing foods, vinegar beverages, condiments, etc.), alcoholic beverages, beverages (such as fruit juice, coffee, tea, soy milk, soy milk, etc.), chemical liquids, traditional Chinese medicine liquids, plant extracts, petroleum refining, chemical refining, metal separation and refining, lithium extraction from salt lakes, seawater refining, and wastewater (including waste acid, waste alkali, waste brine, etc.) treatment; and the above-mentioned freeze concentration method or apparatus is applied in the field of freeze concentration and separation and purification of heat-sensitive raw materials.

[0032] The technical solution of this application will be further described below with reference to specific embodiments.

[0033] Example 1 Figure 1 This is a schematic diagram of the automated continuous-operation cryogenic concentration apparatus in Embodiment 1 of this application. The cryogenic concentration apparatus includes: a freezing component, a melting component, a fractionation component, and a control system 112. The raw liquid is transformed into solid ice by the freezing component. Under the monitoring of the control system 112, the temperature of the solid ice is measured. The control system 112 adjusts the melting component to melt the solid ice and adjusts the fractionation component to fractionate the distillate obtained from the melting of the solid ice to obtain a solution of the corresponding concentration, thus completing the concentration of the raw liquid. The freezing component includes a freezing mechanism 103 and a feed liquid attachment mechanism 102; the melting component includes an ice layer scraping device 109, a solid ice collection device 110, and a melting device 111; the fractionation component includes a near-pure water (extremely low concentration) concentration solution collection tank 113, a target concentration solution collection tank 114, different concentration solution collection tanks 115 and 116, and gate valves 117, 118, 119, 120, 121, and 122.

[0034] The concentration process is as follows: The concentrate is output from the concentrate tank 101 and delivered to the feed liquid attachment mechanism 102 via gate valve 123. During operation, the drive shaft 108 drives the refrigeration mechanism 103 to rotate. At this time, the freezing surface 107 of the refrigeration mechanism 103 contacts the concentrate in the feed liquid attachment mechanism 102. The refrigerant 106 in the refrigeration mechanism 103 exchanges heat with the concentrate through the freezing surface 107. The concentrate adheres to the freezing surface 107 to form a feed liquid film 104. As the heat exchange proceeds, the feed liquid film 104 on the freezing surface 107 of the refrigeration mechanism 103 freezes to form an ice layer 105. As the freezing surface 107 of the refrigeration mechanism 103 rotates, the ice layer scraping device 109 scrapes off the ice layer 105. The ice layer 105 falls into the solid ice collection device 110 and is sent to the melting device 111. The system 112 then controls the process. The automatic fractionation begins. The concentration detection device in control system 112 determines the fraction concentration by detecting the temperature of the solid ice in melting device 111. Based on different fraction concentrations and operating procedures, it controls the opening and closing of gate valves 117, 118, 119, 120, 121, and 122. Solutions that meet the target concentration are sent by control system 112 to the target concentration solution collection tank 114 via gate valve 118 for later use. Solutions that do not meet the target concentration are sent by the automatic fractionation system to different concentration solution collection tanks 115 and 116 via gate valves 119 and 120 according to two concentration standards, and then sent in batches to this freeze-thaw concentration unit for further concentration via gate valves 121 and 122. Solutions with a concentration close to that of pure water (extremely low concentration) are sent to the near-pure water (extremely low concentration) concentration solution collection tank 113 for direct discharge or reuse.

[0035] This cryogenic concentration method and apparatus can be configured with one or more collection tanks for solutions of different concentrations, depending on the process requirements; the number of gate valves can be adjusted according to the number of collection tanks, and the program settings of the automatic fractionation system can be adjusted and modified as needed; other operating steps are the same as above.

[0036] Example 2 Figure 2This is a schematic diagram of the automated continuous operation freeze concentration apparatus in Embodiment 2 of this application. The freeze concentration apparatus includes: a freezing component, a melting component, a fractionation component, and a control system 220. The raw liquid is transformed into solid ice through the freezing component. Under the monitoring of the control system 220, the temperature of the solid ice is measured. The control system adjusts the melting component to melt the solid ice and adjusts the fractionation component to fractionate the distillate obtained from the melting of the solid ice to obtain a solution of the corresponding concentration, thus completing the concentration of the raw liquid. The melting component includes: a heat transfer enhancement component and a melting mass transfer enhancement component. The dashed box A in the figure is the heat transfer enhancement component; the dashed box B in the figure is the melting mass transfer enhancement component; the dashed box C is the fractionation component and the control system 220. The control system 220 obtains the actual temperature of the solid ice by wirelessly receiving the solid ice temperature detector 227, and then controls the opening and closing of each gate valve of the device and the circuit switching of related electrical equipment through wired or wireless means according to the process procedure.

[0037] The concentration process is operated as follows: Step 1: The raw liquid is output from the raw liquid tank 201 and sent to the freezing unit 202 through the gate valve 225; the solid ice formed by freezing the raw liquid is sent to the crushing device 203 to be crushed into ice fragments. The ice fragments are heated to the target concentration through the heat exchange device 204 and become a solid-liquid mixture. The solid-liquid mixture is sent to the insulated storage tank 205 for temporary storage.

[0038] Step 2: Close gate valve 228 and open gate valve 226, keeping the top cover 208 sealed; at this time, the gas heater 218, delivery pump 219, energy medium gas inlet 210, heating mechanism 207, gas-liquid outlet 215, etc. form a closed gas circulation system. After starting the gas heater 218 and delivery pump 219 to bring the internal ambient temperature of the heating mechanism 207 to the target temperature, close gate valve 226 to stop the gas circulation.

[0039] Step 3: Open gate valve 235 and start transfer pump 206 to transport the solid-liquid mixture from insulated storage tank 205 to heating mechanism 207; simultaneously start motors 209 and 216, with motor 216 located between bearing 236 and base 237. The solid-liquid mixture is evenly distributed on the inner wall of rotating basket 212 by distribution device 213 to form ice layer 238 composed of crushed ice. When the thickness of ice layer 238 reaches the level that triggers the ice layer thickness sensing device 211, turn off transfer pump 206 and gate valve 235 to stop the transport of solid-liquid mixture; then, increase the speed of motor 216 to enhance mass transfer by increasing centrifugal force, open gate valve 230, and the separated liquid portion is sent to collection tank 222 by control system 220 for the target concentration solution to be stored for later use.

[0040] Step 4: Reduce (or stop) the rotation speed of the rotating basket 212; set the melting temperature to the required temperature T1, close gate valve 228 and open gate valve 226. At this time, the gas heater 218, the transfer pump 219, the energy medium gas inlet 210, the heating mechanism 207, and the gas-liquid outlet 215 form a closed gas circulation system. Start the gas heater 218 and the transfer pump 219 to heat the ice layer 238. When the temperature of the solid ice in the rotating basket 212 reaches the target temperature T1, open gate valve 228, increase (start and increase) the speed of the motor 216, increase the centrifugal force to enhance mass transfer, and the separated liquid is sent to the collection tank 223 by the control system 220 after passing through the gas-liquid separator 217 and opening gate valves 231 and 234.

[0041] Step 5: Reduce (or stop) the rotation speed of the rotating basket 212; set the melting temperature to the temperature T2 required by the process, and other operating steps are the same as in Step 4 (the final collected fraction concentration in this step is set close to the concentration of pure water); open gate valves 232 and 233, and all separated liquids in this step are sent to the collection tank 224 by the control system 220.

[0042] Step 6: The remaining solid ice has a solute content close to that of pure water ice. It can be taken out directly and allowed to melt naturally; or a higher melting temperature T3 can be set, and then the same operation method as in Step 4 can be used to melt the solid ice into liquid. Then, the gate valve 229 is opened, and the liquid is sent to the collection tank 221 by the control system 220; it can be discharged directly or reused.

[0043] The liquids in collection tanks 223 and 224 are automatically sent to the method and apparatus in batches by control system 220 for further concentration; control system 220 sends solutions that do not meet the target concentration to collection tanks 223 and 224; solutions that meet the target concentration are sent to collection tank 222.

[0044] This cryogenic concentration method and apparatus can be configured with one or more collection tanks for solutions of different concentrations, depending on the process requirements; the number of gate valves can be adjusted according to the number of collection tanks, and the program settings of the control system can be adjusted and modified as needed; other operating steps are the same as above.

[0045] This method and apparatus can be equipped with automatically opening discharge ports at the bottom of the rotating basket 212 and the bottom of the heat insulation protective jacket 214 according to the needs of the process; and a scraping device is set to automatically remove the ice layer 238 (solute content close to pure water ice) after fractionation and then melt or utilize it.

[0046] The above embodiments demonstrate that this application provides a freeze concentration method that solves the technical problems of continuity and automation in existing freeze concentration methods; it realizes automated and continuous freeze concentration operation, making the freeze concentration process simpler, more automated, more efficient, and more applicable to industrial applications.

[0047] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. All equivalent structural transformations made using the content of this application's specification under the inventive concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A method for freeze concentration, characterized in that, include: The stock solution is obtained and frozen to obtain solid ice. During the melting process under the same conditions, when the temperature of the solid ice reaches a constant, a correlation exists between the maximum cumulative distillate concentration and the solid ice temperature. This correlation serves as the basis for fractionation and concentration operations. Specifically, for solid ice formed from a dilute solution, during the melting process under the same conditions, when the temperature of the solid ice reaches a constant, the maximum amount of cumulative distillate that can be received, or the maximum cumulative distillate, is constant, and the concentration of the maximum cumulative distillate is constant. The temperature of the solid ice is monitored, and the melting temperature is set according to the correlation. The melting and fractionation are adjusted and controlled to achieve precise fractionation to obtain a solution of the target concentration.

2. The freeze-concentration method according to claim 1, characterized in that, The freezing is carried out in a freezing component, which realizes the transformation of the original liquid into solid ice; the melting is carried out in a melting component, which, according to the corresponding relationship, realizes the melting of the solid ice under the corresponding constant temperature conditions to obtain the corresponding maximum cumulative fraction.

3. The freeze-concentration method according to claim 1, characterized in that, The fractionation is carried out in a fractionation assembly, which, according to the corresponding relationship, fractionates the corresponding maximum cumulative fraction obtained from melting under corresponding constant temperature conditions to obtain a solution of the corresponding concentration. The monitoring, setting, and adjustment control are carried out in a control system, which realizes the automated freezing and concentration of the stock solution through an automatic control program device.

4. The freeze-concentration method according to claim 1, characterized in that, According to the aforementioned correspondence, when the temperature of the solid ice reaches a constant during the melting process, the temperature of the last fraction separated in the maximum cumulative fraction is the same as the temperature of the solid ice; the solid ice forms a solid-liquid mixture during the melting process, and the solid temperature and liquid temperature in the solid-liquid mixture are the same.

5. A cryogenic concentration apparatus, characterized in that, The apparatus for implementing the freeze concentration method according to any one of claims 1-4 includes: a freezing component, a melting component, a fractionation component, and a control system; the stock solution is converted into solid ice through the freezing component; under the monitoring of the control system, the temperature of the solid ice is measured; the control system adjusts the melting component to melt the solid ice; and adjusts the fractionation component to fractionate the fraction obtained from the melting of the solid ice to obtain a solution of corresponding concentration, thereby completing the concentration of the stock solution.

6. The cryogenic concentration apparatus according to claim 5, characterized in that, The freezing assembly includes: a freezing mechanism and a liquid adhesion mechanism; wherein, the freezing surface of the freezing mechanism can be a plane, or the surface or inner side of a cylinder, or the surface or inner side of a sphere; the liquid adhesion mechanism forms a liquid film on the freezing surface in a manner including but not limited to: allowing the liquid to adhere to the freezing surface and form a liquid film layer by spraying, sprinkling, or gravity flow.

7. The cryogenic concentration apparatus according to claim 5, characterized in that, The melting component includes: an ice scraping device, a solid ice collection device, and a melting device; wherein, the ice scraping method of the ice scraping device includes: keeping the scraping device stationary while the frozen surface moves, or keeping the frozen surface stationary while the scraping device moves, or both move but there is a displacement difference; the movement method includes: rotation, planar displacement causing a displacement difference between the frozen surface and the scraping device.

8. The cryogenic concentration apparatus according to claim 5, characterized in that, The melting component includes: an enhanced heat transfer component and a melting enhanced mass transfer component; the enhanced heat transfer component includes: a crushing device and a heat exchange device; the heat exchange form of the heat exchange device includes: a partition type, a mixing type, or a regenerative type; the melting enhanced mass transfer component includes: a heating mechanism and an enhanced mass transfer device; the heating method of the heating mechanism includes: using conduction, radiation, or an energy medium to penetrate and crush ice; the enhanced mass transfer method of the enhanced mass transfer device includes: using centrifugal separation or negative pressure extraction.

9. A cryogenic concentration apparatus according to claim 5, characterized in that, An automatic control program device is installed in the control system to achieve automated freeze concentration.

10. The application of a freezing concentration method according to any one of claims 1-4 or a freezing concentration apparatus according to any one of claims 5-9 in the fields of food, cosmetics, biomedicine, petrochemicals, metal processing, and environmental protection.

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