Method and device for preparing heme iron by low-temperature vacuum multi-cavity evaporation linkage

Abstract

The application provides a low-temperature vacuum-multicavity evaporation linkage heme iron preparation method and device, relates to the technical field of biological medicine and functional food deep processing, and solves the problems of local overheating and fouling caused by traditional wall heat transfer.

Description

Technical Field

[0001] This invention relates to the field of biomedicine and functional food deep processing technology, specifically to a method and apparatus for preparing heme iron using a low-temperature vacuum-multi-cavity evaporation linkage. Background Technology

[0002] Heme iron, also known as porphyrin iron, is a natural bioavailable iron found in red blood cells of animals. Due to its high absorption rate and lack of intestinal irritation, it is recognized as one of the most ideal sources of iron. In industrial preparation, heme iron stock solution usually needs to undergo enzymatic hydrolysis, filtration, concentration, and drying.

[0003] Currently, the industry commonly uses multi-effect evaporation or vacuum falling film evaporation technology for heme iron concentration. The basic principle is to use heat conduction to transfer heat to the material through the metal wall, combined with a vacuum system to lower the liquid's boiling point. To improve energy efficiency, some advanced processes have introduced MVR (mechanical vapor recompression) technology, which reduces energy consumption by recovering the latent heat of secondary steam.

[0004] Despite breakthroughs in energy conservation, the following fundamental contradictions remain to be addressed in the actual production of heme iron, a special material: The conflict between thermal sensitivity and heat transfer efficiency: Heme iron is extremely sensitive to temperature. When the temperature exceeds 60°C, its core porphyrin ring is prone to thermal dissociation, leading to the shedding of iron ions. However, traditional evaporation technology relies on wall heat conduction; to maintain the evaporation rate, the heater wall temperature is often much higher than the material's boiling point. The "localized overheating" impact at the boundary layer is the main cause of decreased product bioactivity. The problem of "wall adhesion and scaling" due to high viscosity: As the concentration process progresses, the viscosity of the heme iron solution increases exponentially. High-viscosity fluids flow extremely slowly on the heat exchanger tube walls, easily forming a coking layer (i.e., "tube smearing"). This not only hinders heat transfer efficiency but also leads to poor production continuity due to frequent cleaning, and the presence of coking material in the finished product severely affects its quality. Limited Energy Utilization: Current technologies utilize secondary steam only for its latent heat (thermal energy), neglecting the significant kinetic energy carried by the steam as it escapes from the liquid surface. In multi-stage series systems, there is currently a lack of effective technologies to utilize this kinetic energy to assist material processing. Damage to Biomolecules from Mechanical Shearing: Traditional linkage devices rely on multi-stage mechanical pumps for inter-stage transport. The strong shearing action experienced by high-viscosity materials when passing through the impeller pump easily disrupts the stability of heme iron polypeptide chains. In summary, existing heme iron preparation devices struggle to achieve a balance between ultra-low temperature, non-contact operation, and high efficiency. Therefore, developing a novel evaporation linkage process that completely eliminates the thermal resistance of metal walls and deeply reuses steam kinetic energy has become a technological bottleneck in this field. Summary of the Invention

[0005] Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a method and apparatus for preparing heme iron using a low-temperature vacuum-multi-cavity evaporation linkage, solving the following problems: 1. Solved the problem of "local overheating" in the heat exchange process of heat-sensitive materials on the wall: Existing technology relies on heat transfer through metal walls. To ensure evaporation intensity, the wall temperature is typically much higher than the boiling point of the material. Heme iron is highly susceptible to thermal denaturation in the "boundary layer" closely adhering to the wall, leading to the shedding of iron ions.

[0006] The solution proposed in this invention is as follows: Using "contactless suspension evaporation" technology, the material is pneumatically atomized and heated at the center of the cavity. Heat exchange occurs between the droplets and the vapor, completely eliminating direct contact with the high-temperature metal wall. The droplets undergo self-flash evaporation and cooling in a vacuum, ensuring that the porphyrin ring structure integrity rate of heme iron reaches over 98%.

[0007] 2. Solved the problem of "coking on the wall" in the final stage of concentration for high-viscosity materials: Existing technology: As the concentration increases, the viscosity of heme iron increases dramatically, and it flows very slowly in the heat exchange tube. It is very easy to dry and form a coking layer when heated, commonly known as "sticky tube", which leads to heat transfer failure and produces a large number of defective products.

[0008] The solution of this invention is to utilize "low-temperature air curtain isolation" and "instantaneous phase change in space". High-viscosity materials are concentrated in the form of micron-sized droplets during flight, and the inner wall of the chamber is equipped with a protective air curtain, so that the material is cooled or in a low-viscosity droplet state before it touches the wall, which physically prevents scaling and coking, and increases the continuous operation cycle of the equipment by 5-7 times.

[0009] 3. Solved the problem of "thermal / kinetic energy imbalance" due to low energy utilization of secondary steam: Existing technology: Conventional multi-effect or MVR evaporation only recovers the latent heat (thermal energy) of steam, while the large amount of kinetic energy carried by the steam when it escapes at high speed is wasted.

[0010] The solution proposed in this invention is to achieve "cascaded reuse of steam kinetic energy." This invention uses the secondary steam generated in the previous stage as the "atomization power source"* for the next stage. By utilizing the shock wave generated by the supersonic steam flow to pulverize high-viscosity liquid materials, the energy consumption of a high-power, high-pressure pump is eliminated, achieving a deep coupling of thermal and kinetic energy.

[0011] 4. Solved the problem of "shear damage" to bioactive macromolecules caused by mechanical pump drive: Existing technology: Interstage transport relies on centrifugal pumps or gear pumps. High-intensity mechanical shearing forces and local frictional heat can damage the molecular chains of heme iron peptide complexes, affecting their bioavailability.

[0012] The solution of this invention is to use "vacuum gradient induced conveying", which utilizes the precise pressure difference gradient between each cavity to "suck" the material from the previous stage to the next stage. The entire process does not require mechanical rotor intervention, thus realizing flexible and lossless material transmission.

[0013] 5. Solved the problem of "rheological deterioration" in high-solids-content slurries before drying: Existing technology: When concentrated to extremely high concentrations, heme iron slurry exhibits non-Newtonian fluid characteristics, making it extremely difficult to flow and subsequently atomize.

[0014] The solution proposed in this invention is the introduction of "low-frequency acoustic resonance flow stabilization." A specific frequency of pulsation is applied to the interstage channel, utilizing acoustic vibration to disrupt the boundary layer of the high-viscosity fluid and lower its shear-thinning critical point. This allows the material to maintain good flowability and atomization performance even at extremely high concentrations before entering the final drying stage, laying the foundation for the preparation of ultra-high purity heme iron powder.

[0015] Technical solution To achieve the above objectives, the present invention provides the following technical solution: a method for preparing heme iron using a low-temperature vacuum-multi-cavity evaporation linkage, comprising the following steps: Sp1. Raw material pretreatment: Animal red blood cell fluid is enzymatically hydrolyzed and separated to obtain heme iron-based solution; Sp2. Establishing a vacuum thermodynamic gradient: Start the multi-cavity evaporator and establish a gradually decreasing pressure gradient between the first-stage evaporator and the last-stage evaporator; at the same time, input the initial heat source into the heating unit of the first-stage evaporator. Sp3. First-stage film boiling: Heme iron-based liquid is sent into the first-stage evaporation chamber, where a falling film is formed on the heated wall for preliminary concentration. The generated secondary steam is not condensed and is directly introduced into the next-stage evaporation chamber as a power source. Sp4. Interstage pneumatic atomization suspension evaporation: The feed liquid initially concentrated by Sp3 is introduced into the next stage evaporation chamber. During the introduction process, the secondary steam generated in Sp3 is used as a gaseous medium. It is mixed with the feed liquid through a gas-liquid two-phase nozzle and sprayed at high speed, so that the feed liquid is broken into micron-sized droplet groups inside the next stage evaporation chamber. The micron-sized droplet groups are suspended and fly without contacting the container wall. They utilize the latent heat released by the secondary steam and the flash evaporation effect under vacuum to achieve instantaneous mass transfer and concentration at the gas-liquid interface. Sp5. Cyclone gas-liquid separation and relay: The gas-liquid mixture that has completed suspension evaporation is separated by a centrifugal cyclone field. The separated concentrate is used as the liquid to be treated and enters the next stage of evaporation chamber. The separated secondary steam continues to be used as the jet power source for the next stage of evaporation chamber, repeating the steps of Sp4 until the predetermined concentration is reached. Sp6. Finished Product Collection: The high-viscosity concentrated slurry discharged from the final stage directly enters the vacuum freeze crystallizer for solidification.

[0016] Preferably, in Sp4, the throat velocity of the gas-liquid two-phase nozzle is designed to be supersonic, and the shock wave generated by the transcritical expansion of secondary steam is used to pulverize the liquid. The suspension flight process occurs in the central axis region of the evaporation chamber. The inner wall of the evaporation chamber is provided with a low-temperature protective air curtain in the same direction as the jet direction to ensure that the micron-sized droplet group does not come into contact with the high-temperature chamber wall during the flight evaporation process, thereby realizing an evaporation process without wall thermal degradation.

[0017] Preferably, during the relay process of Sp5, as the number of stages increases, the viscosity of the liquid increases. The control system adjusts the gas-liquid mass ratio of the secondary steam introduced into the gas-liquid two-phase nozzle so that the gas-liquid ratio of the subsequent nozzle is 10%-20% higher than that of the previous nozzle, in order to compensate for the atomization resistance caused by the increase in viscosity and maintain the droplet size within the range of 20μm-50μm.

[0018] The apparatus for the preparation of heme iron using a low-temperature vacuum-multi-cavity evaporation linkage method includes: The first-stage falling film evaporator is used to generate the initial secondary steam flow; A suspended flash evaporation linkage module, consisting of a series-connected pneumatic suspended evaporation chamber; the pneumatic suspended evaporation chamber is characterized by its hollow interior, without heating coils or heating jackets; a supersonic vapor-liquid coupling injector is located at the center of the top of the chamber; the supersonic vapor-liquid coupling injector has two inlets: one is a steam power inlet, connected to the steam outlet of the previous chamber; the other is a liquid inlet, connected to the liquid outlet of the previous chamber; the supersonic vapor-liquid coupling injector is configured to utilize the kinetic energy of the steam entering through the steam power inlet to atomize the liquid entering through the liquid inlet and spray it into the internal space of the chamber.

[0019] Preferably, a cyclone separator is connected to the bottom of the pneumatic suspension evaporation chamber, and the steam outlet of the cyclone separator is connected to the steam power inlet of the next stage pneumatic suspension evaporation chamber, forming a "steam kinetic energy reuse chain". The inner wall of the cyclone separator is made of microporous sintered metal material, and its exterior is wrapped with a backflush chamber for periodically blowing pulsed gas inward to prevent high-viscosity heme iron from adhering to the separator wall during the separation process.

[0020] Preferably, the device further includes a resonant flow stabilization system, which includes pressure pulsation generators installed on the connecting pipes at each stage; the pressure pulsation generators are configured to introduce low-frequency sound waves with a frequency of 50Hz-200Hz into the steam flow, using the sound wave vibration to disrupt the boundary layer of the liquid during pipeline transmission, reduce the shear thinning critical point of the high-viscosity heme iron fluid, and assist it in smoothly entering the ejector.

[0021] Preferably, the steam outlet of the pneumatic suspension evaporation chamber is connected to a vacuum pump unit, and a heat pump condenser is provided on the connecting pipeline; the heat pump condenser transports the recovered heat energy back to the heating side of the first-stage falling film evaporator through a circulating medium, forming a closed-loop heat energy circuit.

[0022] Beneficial effects This invention provides a method and apparatus for preparing heme iron using a low-temperature vacuum-multi-cavity evaporation linkage system. It offers the following advantages: 1. Traditional evaporation involves materials adhering to a metal wall at 70℃-90℃. This invention, however, utilizes pneumatic suspension technology to evaporate the material as micron-sized droplets within a vacuum space along the central axis of the cavity. During flash evaporation, the water vaporizes and absorbs its own sensible heat, ensuring the internal temperature of the droplets remains below the saturation temperature under vacuum. The heme iron processed using this method exhibits a more than 15% higher structural integrity of its iron porphyrin rings compared to traditional falling film evaporation.

[0023] 2. The material no longer flows slowly along the tube wall due to gravity, but instead travels at high speed as droplet clusters of 20μm-50μm. The droplets undergo core concentration before contacting the tube wall, which is further protected by a cold air curtain. Because coking and scaling on the heat exchange surface are completely eliminated, the continuous operating time (CIP cleaning interval) of the unit can be increased from the traditional 24 hours to over 168 hours, significantly reducing the consumption of cleaning water and acid / alkali solutions.

[0024] 3. Existing technologies only utilize the latent heat of secondary steam, while this invention innovatively uses it as the atomization power source. By using the supersonic shock wave generated by the steam in the previous stage to pulverize the liquid in the next stage, the power consumption of the high-power high-pressure pump is eliminated. This "steam-driven material" linkage method enables the multi-stage system to form a closed-loop dynamic balance, and the overall thermal efficiency is improved by about 20%-30% compared with the traditional triple-effect evaporator.

[0025] 4. The entire linkage process relies on natural suction and pneumatic injection through interstage pressure gradients, replacing traditional centrifugal or rotary pumps. This avoids the strong shearing damage to the heme iron peptide complex by mechanical impellers, resulting in higher bioavailability (absorption rate) of the final product. Attached Figure Description

[0026] Figure 1 This is a compositional cloud diagram of the heme iron preparation system of the present invention; Figure 2 This is a system architecture diagram of the present invention; Figure 3 This is a flowchart illustrating the workflow of the present invention. Figure 4 This is a diagram showing the physical structure of the device of the present invention; Figure 5 This is a comparative analysis diagram of the physical mechanism of the present invention; Figure 6 This is a diagram illustrating the tracking and protection of activity indicators in this invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all 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. Specific Implementation Example 1: like Figure 1-6 As shown, the method for preparing heme iron using a low-temperature vacuum-multi-cavity evaporation linkage includes the following steps: Sp1. Raw material pretreatment: Animal red blood cell fluid is enzymatically hydrolyzed and separated to obtain heme iron-based solution; Sp2. Establishing a vacuum thermodynamic gradient: Start the multi-cavity evaporator and establish a gradually decreasing pressure gradient between the first-stage evaporator and the last-stage evaporator; at the same time, input the initial heat source into the heating unit of the first-stage evaporator. Sp3. First-stage film boiling: Heme iron-based liquid is sent into the first-stage evaporation chamber, where a falling film is formed on the heated wall for preliminary concentration. The generated secondary steam is not condensed and is directly introduced into the next-stage evaporation chamber as a power source. Sp4. Interstage pneumatic atomization suspension evaporation: This is the core step of this method. The feed liquid, which has been preliminarily concentrated by Sp3, is introduced into the next stage evaporation chamber. During the introduction process, the secondary steam generated in Sp3 is used as a gaseous medium. It is mixed with the feed liquid through a gas-liquid two-phase nozzle and sprayed at high speed, so that the feed liquid is broken into micron-sized droplet groups inside the next stage evaporation chamber. The micron-sized droplet groups are suspended and flying without contacting the container wall. They utilize the latent heat released by the secondary steam and the flash evaporation effect under vacuum to achieve instantaneous mass transfer and concentration at the gas-liquid interface. Sp5. Cyclone gas-liquid separation and relay: The gas-liquid mixture that has completed suspension evaporation is separated by a centrifugal cyclone field. The separated concentrate is used as the liquid to be treated and enters the next stage of evaporation chamber. The separated secondary steam continues to be used as the jet power source for the next stage of evaporation chamber, repeating the steps of Sp4 until the predetermined concentration is reached. Sp6. Finished Product Collection: The high-viscosity concentrated slurry discharged from the final stage directly enters the vacuum freeze crystallizer for solidification.

[0029] Regarding Sp1. Raw material pretreatment (coupling of enzymatic hydrolysis and ultrafiltration): In Sp1, the enzymatic hydrolysis process uses a complex protease, with strict temperature control at 45℃-50℃ and pH value at 6.5-7.5. An antioxidant color-protecting agent is added to lock in the ferrous iron in heme iron before water evaporation, preventing it from being oxidized to ferric iron during subsequent concentration, thus avoiding loss of activity. The introduction of an ultrafiltration membrane (50kDa molecular weight cutoff) is not only for purification but, more importantly, to reduce the initial viscosity of the feed solution, ensuring a uniform flash evaporation effect when entering the interstage throttling channel, rather than a clumpy spray.

[0030] Regarding Sp2 gradient vacuum pre-degassing (heatless deoxygenation): The degassing tank employs a three-stage pressure reduction design, with pressure gradually decreasing from atmospheric pressure to 20 kPa. By installing microporous gas diffusers at the bottom of the tank and introducing a small amount of nitrogen as a carrier gas in a counter-current manner, dissolved oxygen in the heme iron concentrate is forcibly removed using the principle of partial pressure (dissolved oxygen concentration controlled <0.5 mg / L). Emphasis is placed on a "no-heating state" to avoid pre-thermal degradation of the material before it enters the formal evaporation chamber. The deoxygenated concentrate effectively blocks free radical-induced porphyrin ring-opening reactions during subsequent high-temperature (although it is low-temperature evaporation, there is still a temperature rise relative to room temperature) processes.

[0031] Regarding Sp3. Differential pressure driven interstage linkage and flash evaporation: This step eliminates the need for interstage mechanical pumps, utilizing a constant pressure difference of at least 10 kPa between adjacent chambers as the conveying power. When the material passes through an interstage throttling valve equipped with a Venturi structure, it undergoes a sudden transition from a high-pressure zone to a low-pressure zone, resulting in adiabatic expansion flash evaporation. Some of the water in the liquid undergoes explosive vaporization the instant it enters the next chamber, absorbing the sensible heat of the liquid. This process causes the liquid temperature to drop by 5-8°C within milliseconds, offsetting the heat accumulation from the previous stage. Energy coupling: the "secondary steam" evaporated in the previous chamber bypasses the condenser and is directly introduced into the heating jacket of the next chamber. This "latent heat exchange" design increases the coefficient of performance (COP) by more than twice compared to single-effect evaporation.

[0032] Regarding Sp4: Magnetic levitation scraper dynamic film formation (high viscosity treatment): Because heme iron exhibits non-Newtonian fluid properties in the later stages of concentration (solid content >25%), it readily adheres to the walls. This step employs a non-mechanically contactless magnetic levitation drive technology, rotating an internal scraper at 150-300 RPM. The gap between the scraper and the chamber wall is precisely controlled at 0.2-0.5 mm, forcibly spreading the liquid into a uniform film through centrifugal force. Film evaporation significantly reduces the influence of liquid level and hydrostatic pressure on the boiling point, allowing water to escape rapidly below 45°C under extremely low vacuum conditions. Furthermore, the reciprocating shearing action of the scraper reduces the apparent viscosity of the material, maintaining its fluidity.

[0033] Regarding Sp5: Instant freeze-curing (active freshness preservation): The slurry, concentrated to a solids content of 40%-50%, is directly injected into a liquid nitrogen atomization zone at -196°C through a specially designed supersonic nozzle. Technical benefits: The extremely high cooling rate (>1000°C) allows the material to complete its glass transition before water crystallization, forming spherical particles with a microporous structure. Compared to traditional spray drying (inlet air temperature above 150°C), this step completely eliminates thermal damage during the drying stage, and the product exhibits extremely high solubility. Specific Implementation Example 2: like Figure 1-6 As shown, based on the content of the above specific embodiments, the apparatus for the preparation method of heme iron using low-temperature vacuum-multi-cavity evaporation linkage is further disclosed: Linked Evaporation Module: Supersonic Vapor-Liquid Coupled Ejector. Structural Parameters: The ejector employs a gradually contracting-expanding flow channel. The expansion ratio of its throat diameter d to its outlet diameter D is set based on the average pressure of the secondary steam from the previous stage, typically between 1.2 and 1.5. Physical Process: When the secondary steam generated in the previous stage passes through this flow channel, its static pressure energy is converted into kinetic energy, generating a weak shock wave at the outlet. This physical energy level is sufficient to instantly pulverize heme iron slurry with a viscosity as high as 500 mPa·s. Technical Effects: This design solves the problems of low efficiency and shear heat generation in traditional mechanical pumps under high viscosity conditions. It proves that "interstage linkage" is not merely a pipe connection, but a transformation of energy form.

[0035] Evaporation Chamber: Utilizing a magnetically levitated scraper and a non-contact film-forming mechanism, the evaporation chamber is driven by a set of stator excitation coils uniformly arranged outside, with high-temperature resistant permanent magnets embedded in the scraper frame inside. An externally varying rotating magnetic field drives the internal scraper frame to levitate and rotate in a vacuum. Fluid Dynamics Control: The scraper blades are designed with a 15°-30° angle on their water-facing surface. At high speeds, this angle generates a centripetal force pointing towards the central axis of the chamber, which, combined with centrifugal force, forms a dynamically turbulent liquid film on the chamber wall. Anti-scaling Mechanism: The absence of a mechanical shaft penetrating the chamber eliminates material accumulation and bacterial growth points at the mechanical seal. The "zero mechanical contact" between the scraper and the inner wall is maintained by magnetic repulsion, ensuring that the nano-coating on the inner wall does not wear down during long-term operation.

[0036] Interstage connection piping: Venturi effect and energy regulating valve, intelligent regulating valve assembly: The interstage piping is not ordinary stainless steel pipe, but has a built-in self-sensing pressure compensation diaphragm. When the pressure difference between the two stages is detected to be less than 10 kPa, the regulating valve will automatically reduce the flow cross-section, using the Venturi effect to locally increase the flow velocity, ensuring that the material does not stagnate in the pipeline. Thermal compensation layer: The outer layer of the pipeline is wrapped with a vacuum insulation layer and embedded with an electric heating compensation wire, the power of which is linked to the online viscometer. When the viscosity of the material increases, the system slightly increases the pipe wall temperature by 2℃-3℃, reducing boundary layer friction and preventing material from clogging due to stalling during transportation.

[0037] Terminal collection: Vacuum cryogenic granulation tower (coupling interface), pneumatic ejector discharge: The bottom of the last-stage evaporation chamber uses a positive pressure pneumatic ejector system. A very small amount of sterile nitrogen gas is used to instantly force the concentrated slurry into the porous atomizing disc at the head of the granulation tower. Phase change transition: Clear parameter transition when the slurry switches from the vacuum evaporation state to the cryogenic state: The temperature of the slurry entering the granulation tower is maintained at 40℃-45℃, and its residual heat energy is used to perform a final vacuum flash evaporation just before contacting liquid nitrogen, further increasing the solid content.

[0038] Central control unit: Hardware implementation of the thermodynamic balance algorithm; decoupled control architecture: The control system adopts a dual-loop PID control. Loop A: Adjusts the condenser cooling water flow rate based on the terminal vacuum level; Loop B: Adjusts the frequency of the upstream secondary steam booster pump based on interstage pressure drop feedback. Redundancy design: Each evaporation chamber is equipped with high and low dual-position photoelectric liquid level sensors, which prevent material leakage or dry burning accidents through logic gates. This multi-redundancy design is an important indicator of a device with profound innovation. Specific Implementation Example 3: like Figure 1-6 As shown, based on the content of the above specific embodiments, the following content is further disclosed: I. Overall thermodynamic framework principle, energy cascade "frequency conversion" utilization: The working principle of this invention is primarily based on the stepwise conversion of energy grade. Traditional evaporators utilize only the latent heat (enthalpy) of steam, while this system utilizes both the pressure and kinetic energy of the steam. Vacuum gradient establishment (potential energy preset): Before system operation, the vacuum pump unit establishes a stepped pressure field between each stage of the evaporation chamber. The pressure of the first stage chamber is set as P1, the second stage as P2, and the final stage as P3. Significance of the principle: This constitutes the driving force for the flow of matter within the system, replacing the mechanical pump and eliminating the risk of temperature rise caused by the conversion of mechanical energy into heat energy. Latent heat to kinetic energy conversion (phase change driven): When the heme iron molten material in the primary chamber is heated to generate secondary steam, this steam has a certain pressure P. steamKey mechanism: The steam does not condense directly at this stage, but is instead introduced into the next stage of the supersonic ejector. According to Bernoulli's equation and the principles of gas dynamics, as the steam passes through the throat of the Laval nozzle, its pressure potential energy is converted into enormous kinetic energy (velocities reaching 300-500 m / s). Energy conservation: The internal energy of the steam decreases, its temperature drops, but its flow velocity increases. This provides an energy source for the pulverization of materials at low temperatures.

[0040] II. Core Fluid Dynamics Principles: Aerodynamic Suspension and Atomization This is the core mechanism by which the invention solves the problems of wall adhesion and activity loss. Two-fluid shear fragmentation principle: High-velocity secondary steam (gas phase) and low-velocity heme iron slurry (liquid phase) meet in the injector mixing chamber. Weber number mechanism: Due to the huge velocity difference between the gas and liquid phases, the generated aerodynamic shear force is much greater than the surface tension of the droplets. When the Weber number We > 12, large droplets break apart, instantly torn into micron-sized droplets with diameters of 20μm-40μm. Effect: This process greatly increases the specific surface area of ​​the liquid, causing the evaporation efficiency to increase exponentially. Suspended flight evaporation: The atomized droplet group is sprayed into the central vacuum region of the next-stage evaporation chamber. Mass transfer principle: During flight, the droplets are enveloped by secondary steam. Because the chamber maintains a lower vacuum (P... n+1 The water on the surface of the droplet undergoes flash evaporation. Adiabatic cooling effect: Flash evaporation requires the absorption of latent heat. Since the droplet does not contact the heated wall, the heat can only come from the droplet's own sensible heat. Therefore, as the droplet evaporates water, its own temperature drops rapidly. This explains why this device can protect the biological activity of heme iron—the evaporation process is a cooling process.

[0041] III. Boundary layer control principle, rheological intervention of magnetic levitation scrapers: Although most of the water is removed during levitation, some of the concentrate eventually settles to the chamber wall. The working principle at this point is as follows: Non-contact torque transmission: An external rotating magnetic field penetrates the stainless steel chamber wall, coupling with an internal permanent magnet scraper. Principle: This eliminates the need for a mechanical shaft seal, ensuring the maintenance of a high vacuum and preventing external microbial contamination. Forced turbulent film formation: Heme iron concentrate is a pseudoplastic fluid (non-Newtonian fluid), characterized by "the higher the shear rate, the lower the viscosity." Rheological mechanism: The high-speed rotation of the magnetically levitated scraper applies high-intensity shear stress to the material adhering to the wall. This forces the high-viscosity material to thin (shear thinning), forming a turbulent liquid film only 0.5 mm thick. Enhanced heat transfer: The extremely thin liquid film reduces thermal resistance, while the high-speed scraping renews the heat transfer boundary layer, preventing the material from undergoing thermal denaturation (coking) due to prolonged residence time on the wall.

[0042] IV. System Cooperative Control Principle, Adaptive Dynamic Equilibrium: How does the system ensure that there is no "choking" or "draining" between stages? It relies on the negative feedback coupling of pressure and flow. The inter-stage blockage self-healing mechanism works as follows: Operating condition: The viscosity of the material in stage N suddenly increases, causing the flow rate to stage N+1 to slow down, and the pipeline pressure to rise. Response principle: The intelligent control system monitors the pressure P... pipe Increased steam pressure – identified as a precursor to blockage – instructs the (N-1)th stage steam booster pump to increase its frequency – increasing the steam kinetic energy obtained by the Nth stage – enhancing ejector suction – clearing the blockage. Dynamic optimization of the gas-liquid ratio (GLR): The system calculates GLR=M in real time. steam / M liquid Principle: In the early stage of concentration (low viscosity), maintain a low GLR to save energy; in the late stage of concentration (high viscosity), automatically increase the GLR to utilize more steam kinetic energy to overcome viscous resistance and ensure atomization effect.

[0043] V. Summary of Working Principles (Technical Logic Chain): The workflow of this invention is a closed-loop physical process: Source: utilizing waste heat (secondary steam) from the previous stage; Conversion: converting waste heat into high-speed kinetic energy through a Laval nozzle; Action: using kinetic energy to pulverize and suspend the heat-sensitive liquid; Phase Change: achieving low-temperature self-cooling evaporation under a vacuum gradient; Protection: using magnetic levitation shearing to prevent residue on the wall surface. This principle chain completely changes the traditional evaporator's "static heating, passive evaporation" mode, transforming it into "dynamic injection, active flash evaporation," thereby achieving the high-activity, high-purity preparation of heme iron. Specific Implementation Example 4: like Figure 1-6 As shown in the above specific embodiments, the following content is further disclosed, and specific use cases are provided below: Experimental data and performance comparison: In order to further verify the technical effect of the "low temperature vacuum-multi-cavity evaporation linkage method and device for preparing heme iron" described in this invention, the applicant conducted a comparative experiment under the same raw material specifications (pig blood red blood cell enzymatic hydrolysate, initial solid content 8%, initial temperature 25℃) and the same processing capacity (1000kg / h).

[0045] 1. Experimental Group Setup Example 1 (Invention): The pneumatic suspension-multi-cavity linkage evaporation device described in this specification was used. Parameter settings: first-stage heating temperature 55℃, inter-stage pressure difference 12kPa, supersonic nozzle throat velocity 1.3Ma, and final-stage magnetic levitation scraper rotation speed 240rpm.

[0046] Comparative Example 1 (Conventional Technology): A conventional triple-effect falling film evaporator was used. Parameter settings: first-effect heating temperature 85℃, vacuum degree -0.08MPa, and material flowed along the tube wall by gravity.

[0047] Comparative Example 2 (Advanced Existing Technology): Employing an MVR (Mechanical Vapor Recompression) plate evaporator. Parameter settings: Heating temperature difference ΔT = 12℃, forced circulation pump flow rate 50m³ / h. 3 / h.

[0048] Table 1. Comparison of Product Quality and Physicochemical Indicators: This table is intended to demonstrate the absolute advantage of the present invention in terms of active protection.

[0049]

[0050] Table 2. Comparison of Operational Stability and Energy Consumption: This table aims to demonstrate the technological breakthroughs of this invention in terms of industrial continuity and energy conservation.

[0051]

[0052] In-depth analysis of experimental results: (1) Explanation of the mechanism for the significant improvement in activity retention: In Comparative Examples 1 and 2, the material had to flow in close contact with the metal heating wall. Although the temperature difference was controlled in Comparative Example 2, the actual heating temperature of the boundary layer liquid was still close to 70°C, and the high viscosity resulted in a slow flow rate and a long heating time (average residence time > 10 min). In contrast, Example 1 used suspended flight evaporation. The material flew in the vacuum in the form of micron-sized droplets, and the heating time was only in the millisecond range (0.5 s ~ 1.5 s). Moreover, according to thermodynamic principles, when the droplets flash evaporated in the vacuum, the water vaporized and carried away the heat, and the core temperature of the droplets was always maintained at 40°C-45°C. This dual protection of low temperature and instantaneous flow is the fundamental reason why the iron porphyrin retention rate reached 99.1%.

[0053] (2) Explanation of the mechanism for solving the "sticking" problem: Comparative Example 1 required shutdown and cleaning after 20 hours of operation because heme iron at a concentration of 35% exhibits extremely strong adhesion. Once a coking point forms on the tube wall, the thermal resistance increases rapidly, leading to evaporation stagnation. Example 1 utilizes supersonic vapor flow as a carrier, allowing the material to complete 80% concentration in space without contacting the vessel wall. Even when the final stage reaches a high viscosity state, the forced shearing force provided by the magnetic levitation scraper prevents the material from remaining on the wall, thus achieving continuous operation for up to one week.

[0054] (3) Microscopic morphology analysis (SEM scanning electron microscopy data): Product of Example 1: It is a loose hollow sphere with micropores on the surface (caused by gas flash evaporation). This structure is very conducive to the permeation of human gastric acid and has high bioavailability. Product of Comparative Example 1: It is a dense block or sheet with obvious melting and sintering traces (coking characteristics) on the surface and is extremely difficult to dissolve. Specific Implementation Example 5: like Figure 1-6As shown in the above specific embodiments, the following content is further disclosed, and specific use cases are provided below: Case Background: A production line with an annual output of 150 tons of highly active heme iron. Raw material: Porcine red blood cell enzymatic hydrolysate (initial moisture content 92%, solids content 8%). Challenges: The raw material is highly susceptible to oxidation and blackening; viscosity increases exponentially with concentration. Traditional processes begin to coke and adhere to the walls after concentration to approximately 20%. Goal: To concentrate the slurry to a solids content of 45%, with an iron porphyrin retention rate >98%.

[0056] 1. Start-up and gradient pressure differential establishment (system's "standby" state): The operator starts the vacuum pump unit via the central control system. Real-time data: The absolute pressures of evaporation chambers 1, 2, and 3 stabilize at 45 kPa, 20 kPa, and 5 kPa, respectively. System judgment: Sensor feedback ΔP 1-6 =25kPa, which meets the "interstage pressure gradient" setting, and the system issues a "feed allowed" command.

[0057] 2. Primary incentives and motivation generation: The heme iron concentrate enters the first-stage falling film evaporator at a flow rate of 500 L / h. Operating status: Externally supplied 0.15 MPa clean steam heats the walls, and the concentrate begins to boil at 52°C. Key turning point: The secondary steam (52°C saturated gas) generated in the first stage is no longer sent to the condenser, but instead is injected at high speed through an insulated pipeline into the supersonic ejector at the top of chamber 2.

[0058] 3. Transcritical atomization and suspended evaporation: Operating conditions: The concentrated liquid (15% solids content) output from chamber 1 is "drawn" into ejector 2 under pressure differential, where it encounters high-speed secondary steam. Microscopic physical process: The secondary steam, traveling at a supersonic speed of 450 m / s (approximately Mach 1.3), impacts the liquid at the nozzle throat. The liquid is instantly pulverized into droplets approximately 35 μm in diameter, forming a purplish-red "aerosol cone." Judgment logic: The laser particle size analyzer provides real-time feedback on droplet D... 50 The droplet size is 32 μm, and the system maintains the current vapor-liquid ratio (GLR=0.8). Technical effect: The droplet suspends and flies in the center of cavity 2. Due to the higher vacuum, water rapidly migrates to the droplet surface and vaporizes. The measured core temperature of the droplet is only 45℃, far lower than the saturated vapor temperature at this point, achieving "high efficiency and low temperature".

[0059] 4. Magnetic levitation scraper intervention under high viscosity: When the material enters chamber 3, the solid content has reached 35%, and the material has a honey-like viscous consistency. Operating status: The magnetic stator outside the chamber begins to rotate at a frequency of 50Hz. The internal magnetic levitation scraper rotates at 200rpm. Rheological performance: The concentrated liquid settles to the wall surface, with a thickness of approximately 0.4mm. The high-speed shearing of the scraper causes a "shear thinning" effect, instantly reducing the apparent viscosity from 800mPa·s to 200mPa·s. System judgment: Infrared thermal imaging detects an inner wall temperature fluctuation of <±0.5℃, indicating no risk of localized overheating. The protective air curtain is maintained at a low flow rate of 25℃ to prevent droplet adhesion.

[0060] 5. Adaptive balancing under linkage control: During the fourth hour of operation, the viscosity suddenly increased due to batch variations in the raw materials. System response: The differential pressure sensor in chamber 3 detected increased resistance - the control algorithm logic was triggered - the power of the interstage steam booster pump in stage 2 was increased - and the injection kinetic energy was enhanced. Result: The risk of blockage was instantly resolved, and the system automatically returned to equilibrium without interruption.

[0061] 6. Capture and final products: Finally, the concentrated slurry with a solids content of 45% was fed into a liquid nitrogen vacuum granulation tower. Final product: The obtained heme iron microspheres were deep purplish-red with excellent gloss. Physicochemical testing: The iron porphyrin content retention rate was 99.2%, the protein did not undergo thermal denaturation, and the solubility was 40% higher than that of traditional spray-dried products.

[0062] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a reference structure" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0063] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing heme iron using a low-temperature vacuum-multi-cavity evaporation linkage, characterized in that, Includes the following steps: Sp1. Raw material pretreatment: Animal red blood cell fluid is enzymatically hydrolyzed and separated to obtain heme iron-based solution; Sp2. Establishing a vacuum thermodynamic gradient: Start the multi-cavity evaporator and establish a gradually decreasing pressure gradient between the first-stage evaporator and the last-stage evaporator; at the same time, input the initial heat source into the heating unit of the first-stage evaporator. Sp3. First-stage film boiling: Heme iron-based liquid is sent into the first-stage evaporation chamber, where a falling film is formed on the heated wall for preliminary concentration. The generated secondary steam is not condensed and is directly introduced into the next-stage evaporation chamber as a power source. Sp4. Interstage pneumatic atomization suspension evaporation: The feed liquid initially concentrated by Sp3 is introduced into the next stage evaporation chamber. During the introduction process, the secondary steam generated in Sp3 is used as a gaseous medium. It is mixed with the feed liquid through a gas-liquid two-phase nozzle and sprayed at high speed, so that the feed liquid is broken into micron-sized droplet groups inside the next stage evaporation chamber. The micron-sized droplet groups are suspended and fly without contacting the container wall. They utilize the latent heat released by the secondary steam and the flash evaporation effect under vacuum to achieve instantaneous mass transfer and concentration at the gas-liquid interface. Sp5. Cyclone gas-liquid separation and relay: The gas-liquid mixture that has completed suspension evaporation is separated by a centrifugal cyclone field. The separated concentrate is used as the liquid to be treated and enters the next stage of evaporation chamber. The separated secondary steam continues to be used as the jet power source for the next stage of evaporation chamber, repeating the steps of Sp4 until the predetermined concentration is reached. Sp6. Finished Product Collection: The high-viscosity concentrated slurry discharged from the final stage directly enters the vacuum freeze crystallizer for solidification.

2. The method for preparing heme iron using low-temperature vacuum-multi-cavity evaporation linkage according to claim 1, characterized in that: In Sp4, the throat velocity of the gas-liquid two-phase nozzle is designed to be supersonic. The shock wave generated by the transcritical expansion of secondary steam is used to pulverize the liquid material. The suspension flight process occurs in the central axis region of the evaporation chamber. The inner wall of the evaporation chamber is provided with a low-temperature protective air curtain in the same direction as the jet direction to ensure that the micron-sized droplet group does not come into contact with the high-temperature chamber wall during the flight evaporation process, thus realizing an evaporation process without wall thermal degradation.

3. The method for preparing heme iron using low-temperature vacuum-multi-cavity evaporation linkage according to claim 1, characterized in that: During the relay process of Sp5, as the number of stages increases, the viscosity of the liquid increases. The control system adjusts the gas-liquid mass ratio of the secondary steam introduced into the gas-liquid two-phase nozzle so that the gas-liquid ratio of the subsequent nozzle is 10%-20% higher than that of the previous nozzle. This compensates for the atomization resistance caused by the increased viscosity and maintains the droplet size within the range of 20μm-50μm.

4. An apparatus for the preparation method of heme iron using the low-temperature vacuum-multi-cavity evaporation linkage method according to any one of claims 1-3, characterized in that, include: The first-stage falling film evaporator is used to generate the initial secondary steam flow; A suspended flash evaporation linkage module, consisting of a series-connected pneumatic suspended evaporation chamber; the pneumatic suspended evaporation chamber is characterized by its hollow interior, without heating coils or heating jackets; a supersonic vapor-liquid coupling injector is located at the center of the top of the chamber; the supersonic vapor-liquid coupling injector has two inlets: one is a steam power inlet, connected to the steam outlet of the previous chamber; the other is a liquid inlet, connected to the liquid outlet of the previous chamber; the supersonic vapor-liquid coupling injector is configured to utilize the kinetic energy of the steam entering through the steam power inlet to atomize the liquid entering through the liquid inlet and spray it into the internal space of the chamber.

5. The apparatus for preparing heme iron using a low-temperature vacuum-multi-cavity evaporation linkage method according to claim 4, characterized in that: The bottom of the pneumatic suspension evaporation chamber is connected to a cyclone separator, and the steam outlet of the cyclone separator is connected to the steam power inlet of the next stage pneumatic suspension evaporation chamber, forming a "steam kinetic energy reuse chain". The inner wall of the cyclone separator is made of microporous sintered metal material, and its exterior is wrapped with a backflush chamber, which is used to periodically blow pulse gas inward to prevent high viscosity heme iron from adhering to the separator wall during the separation process.

6. The apparatus for preparing heme iron using a low-temperature vacuum-multi-cavity evaporation linkage method according to claim 4, characterized in that: The device also includes a resonant flow stabilization system, which includes pressure pulsation generators installed on the connecting pipes at each stage. The pressure pulsation generators are configured to introduce low-frequency sound waves with a frequency of 50Hz-200Hz into the steam flow, using the sound wave vibration to disrupt the boundary layer of the liquid during pipeline transmission, thereby reducing the shear thinning critical point of the high-viscosity heme iron fluid and assisting it in smoothly entering the injector.

7. The apparatus for preparing heme iron using a low-temperature vacuum-multi-cavity evaporation linkage method according to claim 4, characterized in that: The steam outlet of the pneumatic suspension evaporation chamber is connected to a vacuum pump unit, and a heat pump condenser is provided on the connecting pipeline; the heat pump condenser transports the recovered heat energy back to the heating side of the first-stage falling film evaporator through a circulating medium, forming a closed-loop heat energy circuit.

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