A high-quality euphausia superba oil deep extraction continuous extraction treatment method

Abstract

The present application relates to the technical field of deep processing of marine biological resources, and discloses a high-quality Antarctic krill oil deep extraction continuous extraction processing method. Based on the geometric size of the desorption tower and the mass ratio of the slurry, continuous feeding and flow rate are set, a pulse jet system is configured at the top of the tower, an outlet velocity function is given, a jet shear disturbance and particle wall breaking response coupling model in the tower is established, and the group oil release rate is calculated. According to the integral of the solvent volume to the release rate, the oil concentration is obtained, and the saturation judgment is formed by comparing with the upper limit of the solvent saturation, the solvent updating logic of constant volume of bottom liquid discharge and top liquid supplement is constructed, the cumulative extraction amount, residual amount, extraction efficiency and continuous operation boundary are calculated combined with the liquid discharge frequency, so as to solve the problems of uncontrollable raw material ratio and feeding, difficult quantitative flow field and wall breaking behavior, solvent supersaturation and blind time extension, and realize efficient and stable deep continuous extraction of Antarctic krill oil.

Description

Technical Field

[0001] This invention relates to the field of deep processing technology of marine biological resources, specifically a continuous extraction method for deep extraction of high-quality Antarctic krill oil. Background Technology

[0002] Currently, Antarctic krill oil, as a high-value-added marine functional oil rich in ω-3 unsaturated fatty acids and phospholipids, is experiencing rapid market demand growth. In existing industrial production, the extraction of krill oil from Antarctic krill powder mainly employs processes such as organic solvent extraction, impregnation and percolation tower extraction, mechanically stirred batch extraction, and supercritical fluid extraction. Conventional solvent extraction and percolation tower processes typically rely on continuous or intermittent feeding, achieving diffusion and mass transfer of the oil from the solid phase to the solvent phase through natural convection and macroscopic flow generated by stirring under relatively stable liquid-solid contact conditions. Supercritical extraction, on the other hand, utilizes high pressure... Alternatively, mixing fluids can increase solubility to achieve a higher yield.

[0003] However, the aforementioned existing technologies generally suffer from the following common problems: First, the microscopic shear field and pulsating disturbances within the liquid phase are difficult to accurately construct and quantify. The solvent in the column or vessel often exhibits quasi-steady-state flow or simple turbulence. Solid-liquid interface mass transfer mainly relies on a diffusion process driven by the concentration gradient, resulting in a low interface renewal frequency. This leads to a limited oil migration rate per unit time, a long extraction cycle, and low equipment volume utilization. Second, when the solvent is near saturation, it is often replaced only by empirically setting the discharge time or a fixed number of cycles. There is a lack of a quantitative triggering mechanism based on concentration state or mass flux, which easily leads to premature solvent saturation in some areas and insufficient solvent utilization in other areas, resulting in low overall solvent utilization and difficulty in achieving stable, controllable, continuous, and efficient operation. Furthermore, the coupling of liquid phase flow and particle cell disruption behavior in existing technologies mostly remains at the level of experience or simplified empirical formulas. A continuous-time functional relationship has not yet been established between the instantaneous shear rate, shear response time, oil release rate, and solvent volume in the column. There is a lack of quantitative process models that can be used for design and scale-up, resulting in the determination of process parameters (such as spray intensity, renewal frequency, solid-liquid ratio, etc.) relying on trial and error. Current processes often employ decentralized control or experience-based timing for operations such as draining, replenishing, and feeding. This makes it difficult to achieve coordinated matching of continuous feeding, periodic perturbation, and periodic draining within the same timeframe, resulting in insufficient continuity and difficulty in maintaining stable product quality while ensuring high yield. Furthermore, in terms of Antarctic krill oil quality control, traditional long-duration static or weakly perturbed extraction processes lead to prolonged residence time of oil in localized high-concentration areas, making it prone to oxidation, polymerization, and other deterioration reactions. This increases the difficulty of obtaining high-quality krill oil. Existing technologies lack the means to proactively shorten the residence time at high concentrations and avoid excessive localized residence through calculable mass transfer and renewal mechanisms.

[0004] Therefore, this study aims to propose a continuous extraction method for deep extraction of high-quality Antarctic krill oil. First, by setting the desorption tower size and slurry ratio, the feed rates of raw materials and solvents are precisely controlled. Second, a pulse jet system is used to achieve quantitative perturbation at a programmable jet speed. Then, based on fluid shear and jet speed changes, a shear perturbation model and a particle cell disruption response model are established to accurately quantify the oil release from individual particles and particle groups. Next, the oil release rate is accumulated in real time, and the need for draining and replenishing is determined according to the upper limit of solvent saturation to ensure that the solvent remains within its efficient operating range. Subsequently, the amount of residual oil is evaluated through the number of draining cycles and replenishment logic. Finally, the system extraction efficiency is calculated as the ratio of the extracted amount to the theoretically extractable total amount, and the time boundary for continuous operation is set accordingly. Summary of the Invention

[0005] This invention provides a method for deep and continuous extraction of high-quality Antarctic krill oil, which helps to solve the problems mentioned in the background art.

[0006] This invention provides the following technical solution: a method for deep extraction and continuous extraction of high-quality Antarctic krill oil, comprising:

[0007] Obtain the dimensions of the desorption tower and the preset mass ratio, and set the feeding method and mass flow rate of the mixed slurry;

[0008] A pulse jet system is installed at the top of the desorption tower. The nozzle arrangement, jet cycle and duration are set. The instantaneous ejection velocity change law at the nozzle outlet is given in the control program and the single jet volume is recorded.

[0009] A jet shear disturbance model was established inside the desorption tower. Based on the structure and the instantaneous ejection velocity change at the nozzle outlet, the shear rate at the characteristic position and the instantaneous acceleration of the instantaneous ejection velocity at the nozzle outlet were calculated.

[0010] A particle cell disruption response model was established, and the degree of cell disruption was obtained based on particle properties and solvent flow and converted into the total rate of group oil release.

[0011] The change in oil concentration in the solvent is obtained by accumulating the total oil release rate based on the total volume of solvent in the desorption tower, and an upper limit for solvent saturation judgment is established based on the upper limit of the saturated solubility concentration of Antarctic krill oil.

[0012] The discharge and replenishment logic is constructed around the upper limit of solvent saturation. When the upper limit is reached, the solvent-oil phase mixture is discharged from the bottom and new solvent is added from the top. When the upper limit is not reached, the existing solvent state in the desorption tower is maintained.

[0013] During continuous feeding and periodic drainage, the number of drainage times and variables are recorded. The cumulative oil mass obtained through drainage is calculated and compared with the total theoretically extractable oil mass entering the desorption tower to evaluate the residual oil mass.

[0014] The cumulative oil extraction efficiency is calculated based on the ratio of the cumulative oil mass to the theoretically extractable total oil mass, and the time boundary conditions for continuous process operation are set according to the solvent spraying cycle and the time interval between two adjacent feeds.

[0015] Optionally, obtaining the desorption tower dimensions and preset mass ratio, and setting the feeding method and mass flow rate of the mixed slurry, specifically includes:

[0016] Obtain the height and inner diameter of the desorption tower body, and calculate the inner radius of the desorption tower body according to the cylindrical structure;

[0017] The desorption tower body is constructed as a vertical cylindrical structure, and the effective internal volume of the desorption tower body is obtained based on the height and inner diameter of the desorption tower body according to the cylindrical volume calculation rules;

[0018] Dehydrated krill powder and solvent are mixed at a preset mass ratio to form a fluid slurry. The preset mass ratio is recorded in the control parameters as the ratio of the mass of solvent to the mass of dehydrated krill powder.

[0019] Given the total mass of the mixed slurry, calculate the mass of dehydrated krill powder and solvent in the mixed slurry according to the preset mass ratio, and use the calculation results as the loading amount of raw materials and solvent in the desorption tower.

[0020] During the feeding stage, the mass flow rate of the mixed slurry pumped into the desorption tower per unit time is set, and the mass flow rate of the dehydrated krill powder entering the desorption tower per unit time is calculated according to the preset mass ratio. The calculated mass flow rate of the dehydrated krill powder is used as the infeed rate of the dehydrated krill powder.

[0021] Optionally, the step of installing a pulse jet system at the top of the desorption tower, setting the nozzle arrangement, jet cycle, and duration, and providing the instantaneous ejection velocity variation law at the nozzle outlet and recording the single jet volume in the control program, specifically includes:

[0022] A single-hole nozzle is installed at the center of the top of the desorption tower. The nozzle outlet orifice diameter is recorded and the geometric cross-sectional area of ​​the nozzle outlet is calculated based on the orifice diameter.

[0023] In the control program, the solvent spraying cycle and the spraying duration within a single solvent spraying cycle are set so that the spraying duration is shorter than the solvent spraying cycle.

[0024] Set time conversion rules in the control program to map the continuous running time to the conversion time range of a single solvent spraying cycle, and divide the spraying phase and the stop spraying phase in each solvent spraying cycle accordingly;

[0025] The maximum ejection speed that the nozzle can achieve in a single solvent ejection cycle is obtained, and the instantaneous ejection speed at the nozzle outlet is adjusted according to a preset periodic change curve of first increasing and then decreasing during the ejection phase. During the stop-spray phase, the instantaneous ejection speed at the nozzle outlet is maintained at the initial value of the speed base.

[0026] Based on the preset periodic change curve of first increasing and then decreasing and the geometric cross-sectional area of ​​the nozzle outlet, the instantaneous flow rate of the spraying stage is accumulated in time sequence to obtain the volume of solvent ejected from the nozzle in a single solvent spraying cycle. The volume of solvent ejected from the nozzle in a single solvent spraying cycle is taken as the single spray volume.

[0027] Optionally, the step of establishing a jet shear disturbance model within the desorption tower, and calculating the shear rate at characteristic locations and the instantaneous acceleration of the instantaneous jet velocity at the nozzle outlet based on the structure and the instantaneous jet velocity changes at the nozzle outlet, specifically includes:

[0028] Based on the structure of the desorption tower and the flow characteristics of the nozzle jet after entering the desorption tower, the radial secondary turbulence formed by the jet in the desorption tower is taken as the shear disturbance object.

[0029] A characteristic location is selected inside the desorption tower. Based on the instantaneous ejection velocity at the nozzle outlet and the dimensions of the desorption tower, the change of the local shear rate at the selected characteristic location over time is calculated according to the definition of shear rate in fluid mechanics.

[0030] During the propagation of the jet along the axial direction of the desorption tower, the rate of change of the instantaneous ejection velocity at the nozzle outlet with time is obtained by subtracting the velocity change trend based on the curve of the instantaneous ejection velocity at the nozzle outlet with time. The rate of change of the instantaneous ejection velocity at the nozzle outlet with time is then used as the instantaneous acceleration of the instantaneous ejection velocity at the nozzle outlet.

[0031] Optionally, the establishment of the particle cell disruption response model, which obtains the degree of cell disruption based on particle properties and solvent flow and converts it into the total rate of group oil release, specifically includes:

[0032] The material density, characteristic diameter, and dynamic viscosity of the solvent of a single krill particle are obtained, and the time characteristic coefficients characterizing the shear response rate of the particle are obtained by combining the solvent shear field characteristics.

[0033] By combining the time characteristic coefficients that characterize the shear response rate of particles with the local shear rate obtained in the shear perturbation model, the particle cell wall breakage response relationship is established, and the changes in the degree of cell wall breakage of individual particles and the degree of oil release completion with time under different shear intensities and cumulative shear action are obtained.

[0034] Given the total number of krill particles participating in the current extraction process and the oil content of each particle, the oil release rate of each particle at the same time point is calculated based on the change in oil release completion over time. The oil release rates of all particles are added together to obtain the total rate of oil released into the solvent at the same time point.

[0035] Optionally, the step of obtaining the change in oil concentration in the solvent based on the total rate of oil release accumulated by the total volume of solvent in the desorption tower, and establishing an upper limit for solvent saturation determination based on the upper limit of the saturated solubility concentration of Antarctic krill oil, specifically includes:

[0036] Obtain the total volume of solvent in the desorption tower, and use the mass of oil per unit volume in the solvent as the oil concentration variable during operation;

[0037] Based on the obtained total oil release rate, the mass of oil released within a given time interval will be evenly distributed into the total volume of solvent in the desorption tower. By accumulating the oil concentration increment within each time interval, the change of oil concentration in the solvent over time will be updated, and the oil concentration will be set as the initial value of the oil concentration at the initial moment.

[0038] Under set temperature and pressure conditions, the upper limit of the saturated solubility concentration of the solvent for Antarctic krill oil is obtained, and the upper limit of the saturated solubility concentration of the solvent for Antarctic krill oil is used as the upper limit of solvent saturation judgment. When the calculated oil concentration reaches or exceeds the upper limit of solvent saturation judgment, the liquid discharge judgment logic is entered.

[0039] Optionally, the discharge and replenishment logic is constructed around the upper limit of solvent saturation determination. When the upper limit is reached, the solvent-oil phase mixture is discharged from the bottom and new solvent is added from the top. When the upper limit is not reached, the existing solvent state in the desorption tower is maintained. Specifically, this includes:

[0040] The discharge judgment logic is constructed based on the upper limit of solvent saturation judgment. The concentration of solvent grease in the desorption tower is checked at any time. When the grease concentration reaches or exceeds the upper limit of solvent saturation judgment, the discharge judgment logic is determined to be in the triggered state. When the grease concentration is lower than the upper limit of solvent saturation judgment, the discharge judgment logic is determined to be in the untriggered state.

[0041] When the discharge judgment logic is triggered, a batch of solvent-oil phase mixture is discharged from the bottom of the desorption tower, and the volume of solvent-oil phase mixture corresponding to a single discharge is set to be the same as the total volume of solvent in the desorption tower.

[0042] While discharging the solvent-oil phase mixture, a new solvent of the same volume and free of grease is added from the top of the desorption tower to keep the total volume of solvent in the desorption tower constant.

[0043] Upon completion of replenishment, reset the solvent and grease concentration in the desorption tower to the initial base value and end the current drainage operation.

[0044] During the period when the drain determination logic is not triggered, the drain operation will not be performed, and the existing solvent state in the desorption tower will be maintained.

[0045] Optionally, the step of recording the number of drainage cycles during continuous feeding and periodic drainage, calculating the cumulative oil mass obtained through drainage, comparing it with the theoretically extractable total oil mass entering the desorption tower, and evaluating the residual oil mass specifically includes:

[0046] During continuous operation, a time axis is used as a reference to record the occurrence of each drainage action. A drainage count record variable is set, and the drainage count record variable is set as the initial value of the counting base at the initial moment.

[0047] On the timeline, when the drainage judgment logic changes from an untriggered state to a triggered state, the value of the drainage count record variable is incremented by one, and the cumulative result of the drainage count record variable is maintained at subsequent times, so that the value of the drainage count record variable at any time is the cumulative value of all previous increment operations.

[0048] Under the premise that the volume of solvent-oil phase mixture corresponding to a single drainage is fixed, the values ​​of the solvent saturation judgment upper limit, the volume of solvent-oil phase mixture corresponding to a single drainage, and the number of drainage records are multiplied to obtain the cumulative oil mass obtained through drainage up to any time.

[0049] When the mass flow rate of dehydrated krill powder is kept constant, the mass flow rate of dehydrated krill powder, the mass fraction of oil in dehydrated krill powder, and the running time are used as parameters. The total mass of oil that can be theoretically completely extracted from the dehydrated krill powder entering the desorption tower at any time is calculated by the time accumulation method, and this total mass of oil is taken as the theoretical total mass of extractable oil.

[0050] At any given time point, the total theoretically extractable oil mass is subtracted from the cumulative oil mass obtained through drainage, and the result is taken as the residual oil mass that has not yet been extracted in the system at the corresponding time point.

[0051] Optionally, the calculation of the cumulative oil extraction efficiency based on the ratio of the cumulative oil mass to the theoretically extractable total oil mass, and the setting of the time boundary conditions for continuous process operation based on the solvent spraying cycle and the time interval between two adjacent feeds, specifically includes:

[0052] Under the condition that both the theoretically extractable total mass of oil and the cumulative oil mass obtained through drainage are greater than the initial mass base, the cumulative oil extraction efficiency of the entire system at any time is calculated by comparing the ratio between the two and according to the ratio of the cumulative oil mass to the theoretically extractable total mass of oil.

[0053] In continuous feed control, the time interval between two adjacent feed operations is set and set to a value greater than the solvent spraying cycle. The time interval between two adjacent feed operations serves as the time boundary condition for continuous process operation, while ensuring a stable time relationship between the feed action, solvent spraying, and draining actions.

[0054] The present invention has the following beneficial effects:

[0055] 1. This scheme tightly couples the geometric parameters of the desorption tower with the preset mass ratio of the mixed slurry, calculating the effective volume within the desorption tower and the mass flow rate of each material, thus achieving precise distribution of the mass of dehydrated krill powder and solvent in the mixed slurry. This parameterization allows for accurate calculation of the feed space information through cylindrical geometry, and also enables flexible adjustment of the mass ratio based on the oil content characteristics of different dehydrated krill powders, thereby balancing extraction rate and material concentration. This method avoids repeated on-site experiments and blind adjustments through mathematical and structured parameter calculations, saving process debugging time. Simultaneously, by calculating the dehydrated krill powder feed rate according to the preset mass ratio, the raw material distribution becomes more uniform, reducing localized oversaturated and overly diluted areas, improving system stability and repeatability.

[0056] 2. This invention introduces a programmable pulse jet system at the top of the desorption tower. By setting the nozzle arrangement, jet cycle, and duration in the control program, and providing the initial increase and subsequent decrease in the instantaneous ejection velocity at the nozzle outlet within each cycle, and recording the volume of a single jet, a regular pulse flow is formed within the tower. The jet velocity curve is functionalized, allowing for precise adjustment of the jet velocity over time. The control program combines the jet cycle and duration to create periodic jetting and stopping phases. Recording the actual jet volume provides real-time data for subsequent model building. Pulse disturbances can significantly enhance liquid-solid contact within the tower. The velocity changes in each jet cycle induce repeated suspension and sedimentation of particles, improving mass transfer and cell disruption efficiency. Simultaneously, the extraction intensity can be adjusted online by changing the cycle and velocity curve, achieving flexible process control and high energy efficiency.

[0057] 3. To deeply characterize the flow field characteristics coupled with the desorption tower structure, this scheme innovatively constructs a jet shear disturbance model within the desorption tower. The model uses the instantaneous ejection velocity at the nozzle exit and the tower's geometric dimensions as inputs to calculate the local shear rate at characteristic locations. The instantaneous acceleration of the instantaneous ejection velocity at the nozzle exit is obtained by subtracting the velocity change trend. By combining the temporal dynamics of the jet velocity with the flow field within the tower, the shear disturbance intensity is quantified. The concept of instantaneous acceleration is introduced to reflect the slope information of the shear rate change over time, capturing dynamic flow pulsations. Compared to static models or single shear rate calculations, the dynamic disturbance model can more accurately describe the instantaneous disturbances and energy input in the flow field, providing more realistic data support for particle wall breaking and mass transfer.

[0058] 4. This scheme innovatively establishes a particle cell disruption response model: based on the material density, characteristic diameter, and solvent dynamic viscosity of a single krill particle, a characteristic response time coefficient is constructed for the particle, and this coefficient is combined with the local shear rate obtained from the shear perturbation model to form a relative completion function, accurately describing the relationship between cell disruption and oil release over time. The particle response time coefficient couples the particle physical properties with the shear field characteristics; a formula-free method for calculating cell disruption completion is established, which is easy to parameterize in practical engineering; and the response function extends the behavior of a single particle to the particle group to achieve the cumulative calculation of the overall oil release rate. Compared with purely experimental experience or simple linear models, this model can provide more refined time-dimensional predictions of cell disruption rates, providing a basis for optimizing injection parameters and shear rates; improving the accuracy of oil release prediction, assisting in process optimization, and reducing trial-and-error costs.

[0059] 5. This innovative solution accumulates the instantaneous total oil release rate across the total solvent volume within the desorption tower, enabling dynamic evolution of oil concentration over time. This data is then compared in real-time with a pre-defined upper limit for solvent saturation, establishing a saturation threshold. Coupled with the concentration evolution equation and the actual release rate, this provides a real-time online concentration monitoring method. Setting the upper concentration threshold triggers an automatic draining logic, allowing the system to generate a draining command when the concentration approaches saturation. Combining dynamic concentration control with the draining and replenishment process achieves a balance between solvent utilization efficiency and extraction efficiency. Compared to static excess solvent or purely time-based draining, this logic significantly saves solvent consumption, avoids decreased extraction efficiency due to oversaturation, ensures the system operates continuously within its optimal operating range, reduces energy and chemical consumption, and enhances production capacity and cost advantages.

[0060] 6. To address the issues of insufficient real-time performance and solvent waste associated with traditional timed draining and replenishment, this solution constructs a draining discrimination function based on the upper limit of solvent saturation. When the concentration reaches the upper limit of saturation, a draining operation is triggered, simultaneously draining a solvent-oil phase mixture equal in volume to the solvent in the column from the bottom, while replenishing the same volume of new solvent from the top. Draining is triggered dynamically based on saturation, eliminating reliance on fixed times; the linkage between draining and replenishment ensures a constant total solvent volume, maintaining stable fluid pressure and liquid level within the column; cumbersome switching of directional valves or multi-stage pumps is eliminated, achieving one-click draining and replenishment solely through programmed judgment. Compared to traditional timed replacement or experience-based replenishment, this logic offers high responsiveness and a minimum solvent replacement volume, maximizing the extraction activity of unsaturated regions, improving solvent utilization efficiency, and enhancing system automation.

[0061] 7. This scheme proposes using the number of drainage cycles as a variable. By fixing the drainage volume and setting a preset upper limit for saturation concentration, the cumulative mass of oil removed in each drainage cycle is calculated. This sum is then combined with the mass flow rate of dehydrated krill powder and the oil content to calculate the theoretically extractable total mass of oil. The difference between the two is the residual oil mass. The entire process is online without sampling; the cumulative drainage volume is obtained by automatically incrementing the number of drainage cycles. Combining the theoretical total with the actual cumulative drainage volume, no additional detection device is required. The method is simple and easy to implement, and can output the residual amount in real time for process adjustment. Compared with interval sampling, this algorithm reduces manual intervention and experimental time, enables continuous monitoring of residual conditions, guides subsequent replenishment or extension of the drainage cycle, and achieves true online closed-loop optimization.

[0062] 8. This innovative solution determines the system's extraction efficiency by calculating the ratio of the cumulative oil mass to the theoretically extractable total amount in real time. Combined with the spray cycle and feeding interval conditions, it dynamically sets the continuous operation time boundary of the process. The extraction efficiency, defined as the ratio of the two, directly reflects the overall system performance. Combined with the dual time constraints of the spray cycle and feeding interval, it ensures sufficient mass transfer and regeneration time within the continuous operation range. The efficiency value can be used for subsequent process optimization and decision support, improving production scheduling and automation management. Compared to traditional periodic sampling evaluation or purely empirical prediction, this method, while ensuring high efficiency, can also avoid over-operation or frequent shutdowns through boundary condition control, ensuring process stability and production continuity. Attached Figure Description

[0063] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0064] 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.

[0065] Example, refer to Figure 1 A method for deep extraction and continuous extraction of high-quality Antarctic krill oil, comprising:

[0066] Obtain the dimensions of the desorption tower and the preset mass ratio, and set the feeding method and mass flow rate of the mixed slurry;

[0067] A pulse jet system is installed at the top of the desorption tower. The nozzle arrangement, jet cycle and duration are set. The instantaneous ejection velocity change law at the nozzle outlet is given in the control program and the single jet volume is recorded.

[0068] A jet shear disturbance model was established inside the desorption tower. Based on the structure and the instantaneous ejection velocity change at the nozzle outlet, the shear rate at the characteristic position and the instantaneous acceleration of the instantaneous ejection velocity at the nozzle outlet were calculated.

[0069] A particle cell disruption response model was established, and the degree of cell disruption was obtained based on particle properties and solvent flow and converted into the total rate of group oil release.

[0070] The change in oil concentration in the solvent is obtained by accumulating the total oil release rate based on the total volume of solvent in the desorption tower, and an upper limit for solvent saturation judgment is established based on the upper limit of the saturated solubility concentration of Antarctic krill oil.

[0071] The discharge and replenishment logic is constructed around the upper limit of solvent saturation. When the upper limit is reached, the solvent-oil phase mixture is discharged from the bottom and new solvent is added from the top. When the upper limit is not reached, the existing solvent state in the desorption tower is maintained.

[0072] During continuous feeding and periodic drainage, the number of drainage times and variables are recorded. The cumulative oil mass obtained through drainage is calculated and compared with the total theoretically extractable oil mass entering the desorption tower to evaluate the residual oil mass.

[0073] The cumulative oil extraction efficiency is calculated based on the ratio of the cumulative oil mass to the theoretically extractable total oil mass, and the time boundary conditions for continuous process operation are set according to the solvent spraying cycle and the time interval between two adjacent feeds.

[0074] By acquiring the geometric dimensions of the desorption tower and the preset mass ratio of the mixed slurry, and setting the feeding method and flow rate, this invention solves the problems of low mass transfer efficiency caused by the difficulty in accurately controlling the ratio of raw materials and solvents and uneven feeding in traditional processes. By setting a programmable pulse jet system at the top of the tower, providing the jet speed variation law and recording the volume, this invention avoids the mixing dead zone and excessive shear zone caused by constant speed jetting, and generates periodic disturbances in the fluid within the tower. By establishing a shear disturbance model and calculating the local shear rate and acceleration, the intensity of the flow field's effect on particles is accurately quantified, overcoming the lack of quantitative description of the dynamic changes in the flow field in existing technologies. By further constructing a particle cell disruption response model and coupling particle physical parameters with shear perturbation, accurate prediction of the release rate of individual particles and groups of oils is achieved, overcoming the unreliability of previous empirical estimations. By dynamically controlling the solvent saturation level through real-time accumulation of the total oil release rate and combining it with the upper limit of solvent saturation, oil retention caused by solvent oversaturation is avoided. A closed-loop logic of bottom drainage and top replenishment ensures constant solvent volume and active solvent regeneration. The residual oil is assessed by comparing the number of drainage cycles with the theoretical total amount, avoiding blindly extending the process operation. Extraction efficiency calculation and time boundary setting make the continuous process both efficient and reliable. Overall, this method improves extraction efficiency, reduces solvent consumption, and enhances process controllability, enabling the industrial-scale implementation of continuous deep extraction.

[0075] The steps of obtaining the desorption tower body dimensions and preset mass ratio, and setting the feeding method and mass flow rate of the mixed slurry, specifically include:

[0076] Obtain the height and inner diameter of the desorption tower body, and calculate the inner radius of the desorption tower body according to the cylindrical structure;

[0077] The desorption tower body is constructed as a vertical cylindrical structure, and the effective internal volume of the desorption tower body is obtained based on the height and inner diameter of the desorption tower body according to the cylindrical volume calculation rules;

[0078] Dehydrated krill powder and solvent are mixed at a preset mass ratio to form a fluid slurry. The preset mass ratio is recorded in the control parameters as the ratio of the mass of solvent to the mass of dehydrated krill powder.

[0079] Given the total mass of the mixed slurry, calculate the mass of dehydrated krill powder and solvent in the mixed slurry according to the preset mass ratio, and use the calculation results as the loading amount of raw materials and solvent in the desorption tower.

[0080] During the feeding stage, the mass flow rate of the mixed slurry pumped into the desorption tower per unit time is set, and the mass flow rate of the dehydrated krill powder entering the desorption tower per unit time is calculated according to the preset mass ratio. The calculated mass flow rate of the dehydrated krill powder is used as the infeed rate of the dehydrated krill powder.

[0081] The height of the desorption tower is denoted as . The inner diameter of the desorption tower body is denoted as . The radius of the desorption tower body is then... ;

[0082] The desorption tower body is a vertical cylinder;

[0083] Calculate the effective internal volume of the desorption tower. ;

[0084] Dehydrated krill powder and solvent were mixed in a mass ratio Mixing, forming a fluid mixed slurry; wherein, The mass ratio of solvent to krill powder;

[0085] Set the total mass of the mixed slurry to be The mass of krill meal in the mixed system is:

[0086] ;in, The quality of the krill powder in the system;

[0087] The mass of solvent in the desorption tower is set to... And the total mass of the mixed slurry and the mass of the krill powder meet the following requirements: ;

[0088] Set the mass flow rate of the mixed slurry pumped into the tower per second to be... The mass of krill meal entering per unit time is: ;in, The feed rate of krill powder is expressed as mass flow rate.

[0089] The process of installing a pulse jet system at the top of the desorption tower, setting the nozzle arrangement, jet cycle, and duration, and providing the instantaneous ejection velocity variation law at the nozzle outlet and recording the single jet volume in the control program, specifically includes:

[0090] A single-hole nozzle is installed at the center of the top of the desorption tower. The nozzle outlet orifice diameter is recorded and the geometric cross-sectional area of ​​the nozzle outlet is calculated based on the orifice diameter.

[0091] In the control program, the solvent spraying cycle and the spraying duration within a single solvent spraying cycle are set so that the spraying duration is shorter than the solvent spraying cycle.

[0092] Set time conversion rules in the control program to map the continuous running time to the conversion time range of a single solvent spraying cycle, and divide the spraying phase and the stop spraying phase in each solvent spraying cycle accordingly;

[0093] The maximum ejection speed that the nozzle can achieve in a single solvent ejection cycle is obtained, and the instantaneous ejection speed at the nozzle outlet is adjusted according to a preset periodic change curve of first increasing and then decreasing during the ejection phase. During the stop-spray phase, the instantaneous ejection speed at the nozzle outlet is maintained at the initial value of the speed base.

[0094] Based on the preset periodic change curve of first increasing and then decreasing and the geometric cross-sectional area of ​​the nozzle outlet, the instantaneous flow rate of the spraying stage is accumulated in time sequence to obtain the volume of solvent ejected from the nozzle in a single solvent spraying cycle. The volume of solvent ejected from the nozzle in a single solvent spraying cycle is taken as the single spray volume.

[0095] A single-orifice nozzle with a diameter of [missing information] is installed at the center of the tower top. The nozzle cross-sectional area is:

[0096] ;in, The diameter of the nozzle outlet orifice; Let be the geometric cross-sectional area of ​​the nozzle outlet;

[0097] Set the solvent spray cycle to The duration of the injection within a single cycle is and satisfy ;

[0098] The time variable is converted into its discounted form within a single period as follows: ;in, It is a continuous-time variable; To make continuous time The converted time mapped to a single injection cycle; For modulo operation;

[0099] The maximum ejection velocity that the nozzle can achieve in one injection cycle is denoted as . ;

[0100] The instantaneous velocity function during the injection period is constructed as follows:

[0101] ;in, In continuous time The instantaneous ejection velocity of the solvent at the outlet of the upper nozzle;

[0102] Calculate the volume of a single injection: ;in, The actual spray duration within one spray cycle The volume of solvent ejected from the nozzle.

[0103] The establishment of the jet shear disturbance model within the desorption tower, and the calculation of the shear rate at characteristic locations and the instantaneous acceleration of the instantaneous jet velocity at the nozzle outlet based on the structure and the instantaneous jet velocity changes at the nozzle outlet, specifically includes:

[0104] Based on the structure of the desorption tower and the flow characteristics of the nozzle jet after entering the desorption tower, the radial secondary turbulence formed by the jet in the desorption tower is taken as the shear disturbance object.

[0105] A characteristic location is selected inside the desorption tower. Based on the instantaneous ejection velocity at the nozzle outlet and the dimensions of the desorption tower, the change of the local shear rate at the selected characteristic location over time is calculated according to the definition of shear rate in fluid mechanics.

[0106] During the propagation of the jet along the axial direction of the desorption tower, the rate of change of the instantaneous ejection velocity at the nozzle outlet with time is obtained by subtracting the velocity change trend based on the curve of the instantaneous ejection velocity at the nozzle outlet with time. The rate of change of the instantaneous ejection velocity at the nozzle outlet with time is then used as the instantaneous acceleration of the instantaneous ejection velocity at the nozzle outlet.

[0107] The jet creates radial secondary turbulence in the desorption tower cavity, resulting in a local shear rate of:

[0108] ;in, In continuous time Local shear rate at a characteristic location within the lower tower;

[0109] The jet acceleration is calculated as follows:

[0110] ;in, In continuous time The instantaneous acceleration of the solvent flow rate at the lower nozzle outlet.

[0111] The establishment of the particle cell disruption response model, which obtains the degree of cell disruption based on particle properties and solvent flow and converts it into the total rate of group oil release, specifically includes:

[0112] The material density, characteristic diameter, and dynamic viscosity of the solvent of a single krill particle are obtained, and the time characteristic coefficients characterizing the shear response rate of the particle are obtained by combining the solvent shear field characteristics.

[0113] By combining the time characteristic coefficients that characterize the shear response rate of particles with the local shear rate obtained in the shear perturbation model, the particle cell wall breakage response relationship is established, and the changes in the degree of cell wall breakage of individual particles and the degree of oil release completion with time under different shear intensities and cumulative shear action are obtained.

[0114] Given the total number of krill particles participating in the current extraction process and the oil content of each particle, the oil release rate of each particle at the same time point is calculated based on the change in oil release completion over time. The oil release rates of all particles are added together to obtain the total rate of oil released into the solvent at the same time point.

[0115] The material density of a single krill pellet is denoted as . The characteristic diameter of the krill particles is recorded as . The dynamic viscosity of the solvent is denoted as . ;

[0116] The response coefficients are constructed as follows: ;in, The characteristic response time coefficient of the particles in the solvent shear field;

[0117] The lipid release function is constructed as follows:

[0118] ;in, In continuous time The lower particles achieve a relatively complete degree of cell wall disruption and oil release due to shearing action; It is an exponential function;

[0119] Set the total number of krill particles participating in the current extraction process to [value]. The mass of oil contained in a single krill pellet is set as follows: The total rate of oil release is:

[0120] ;in, In continuous time The total rate at which all particles release oil into the solvent.

[0121] The change in oil concentration in the solvent is obtained by accumulating the total oil release rate based on the total volume of solvent in the desorption tower, and an upper limit for solvent saturation is established based on the upper limit of the saturated solubility concentration of Antarctic krill oil. Specifically, this includes:

[0122] Obtain the total volume of solvent in the desorption tower, and use the mass of oil per unit volume in the solvent as the oil concentration variable during operation;

[0123] Based on the obtained total oil release rate, the mass of oil released within a given time interval will be evenly distributed into the total volume of solvent in the desorption tower. By accumulating the oil concentration increment within each time interval, the change of oil concentration in the solvent over time will be updated, and the oil concentration will be set as the initial value of the oil concentration at the initial moment.

[0124] Under set temperature and pressure conditions, the upper limit of the saturated solubility concentration of the solvent for Antarctic krill oil is obtained, and the upper limit of the saturated solubility concentration of the solvent for Antarctic krill oil is used as the upper limit of solvent saturation judgment. When the calculated oil concentration reaches or exceeds the upper limit of solvent saturation judgment, the liquid discharge judgment logic is entered.

[0125] Obtain the total volume of solvent in the desorption tower, denoted as ;

[0126] Set in continuous time The mass of oil contained in a unit volume of the solvent is ;

[0127] The equation for the evolution of concentration over time is constructed as follows: , ;

[0128] The upper limit of the saturated solubility concentration of the solvent for Antarctic krill oil under set temperature and pressure conditions is obtained, denoted as . ;

[0129] When satisfied Then the process of determining the drainage begins.

[0130] The discharge and replenishment logic is constructed around the upper limit of solvent saturation. When the upper limit is reached, the solvent-oil phase mixture is discharged from the bottom and new solvent is added from the top. When the upper limit is not reached, the existing solvent state in the desorption tower is maintained. Specifically, this includes:

[0131] The discharge judgment logic is constructed based on the upper limit of solvent saturation judgment. The concentration of solvent grease in the desorption tower is checked at any time. When the grease concentration reaches or exceeds the upper limit of solvent saturation judgment, the discharge judgment logic is determined to be in the triggered state. When the grease concentration is lower than the upper limit of solvent saturation judgment, the discharge judgment logic is determined to be in the untriggered state.

[0132] When the discharge judgment logic is triggered, a batch of solvent-oil phase mixture is discharged from the bottom of the desorption tower, and the volume of solvent-oil phase mixture corresponding to a single discharge is set to be the same as the total volume of solvent in the desorption tower.

[0133] While discharging the solvent-oil phase mixture, a new solvent of the same volume and free of grease is added from the top of the desorption tower to keep the total volume of solvent in the desorption tower constant.

[0134] Upon completion of replenishment, reset the solvent and grease concentration in the desorption tower to the initial base value and end the current drainage operation.

[0135] During the period when the drain determination logic is not triggered, the drain operation will not be performed, and the existing solvent state in the desorption tower will be maintained.

[0136] The discharge discrimination function is constructed as follows: ;in, In continuous time The determination status of whether the drainage action has been triggered;

[0137] when Perform the drainage operation at the appropriate time;

[0138] when Drainage procedures are not performed at this time;

[0139] Set the volume of the solvent-oil phase mixture discharged from the bottom of the column in a single draining operation to be [missing value]. And satisfy ;

[0140] exist The moment is discharged from the bottom of the tower The solvent-oil phase mixture was added at the top of the column by the same volume. A new solvent with an oil concentration of 0 is used to maintain the total solvent volume in the desorption tower at a certain level. constant;

[0141] The following conditions must be met at the moment the drainage process is completed: .

[0142] The process of recording the number of drainage cycles during continuous feeding and periodic drainage, calculating the cumulative oil mass obtained through drainage, and comparing it with the theoretically extractable total oil mass entering the desorption tower to evaluate the residual oil quality, specifically includes:

[0143] During continuous operation, a time axis is used as a reference to record the occurrence of each drainage action. A drainage count record variable is set, and the drainage count record variable is set as the initial value of the counting base at the initial moment.

[0144] On the timeline, when the drainage judgment logic changes from an untriggered state to a triggered state, the value of the drainage count record variable is incremented by one, and the cumulative result of the drainage count record variable is maintained at subsequent times, so that the value of the drainage count record variable at any time is the cumulative value of all previous increment operations.

[0145] Under the premise that the volume of solvent-oil phase mixture corresponding to a single drainage is fixed, the values ​​of the solvent saturation judgment upper limit, the volume of solvent-oil phase mixture corresponding to a single drainage, and the number of drainage records are multiplied to obtain the cumulative oil mass obtained through drainage up to any time.

[0146] When the mass flow rate of dehydrated krill powder is kept constant, the mass flow rate of dehydrated krill powder, the mass fraction of oil in dehydrated krill powder, and the running time are used as parameters. The total mass of oil that can be theoretically completely extracted from the dehydrated krill powder entering the desorption tower at any time is calculated by the time accumulation method, and this total mass of oil is taken as the theoretical total mass of extractable oil.

[0147] At any given time point, the total theoretically extractable oil mass is subtracted from the cumulative oil mass obtained through drainage, and the result is taken as the residual oil mass that has not yet been extracted in the system at the corresponding time point.

[0148] Set deadline The function of the number of drainage cycles is: The function satisfies the following conditions:

[0149] S701, initial conditions are: ;in, In continuous time The number of times fluid has been discharged previously, including this moment;

[0150] S702, On the timeline, when When the value changes from 0 to 1, The value increases by 1;

[0151] S703, at any time place, This is the cumulative result of the aforementioned additional operations;

[0152] If the volume of fluid drained each time is the same Then the deadline The cumulative extracted oil mass is:

[0153] ;in, In continuous time The total cumulative mass of oil obtained previously through drainage;

[0154] Krill meal mass flow rate Under constant conditions, the theoretical total oil content is:

[0155] ;in, This represents the mass fraction of oil in the original krill meal. In continuous time The total mass of oil that could theoretically be completely extracted from krill meal entering the tower;

[0156] Calculate the deadline The residual oil mass is:

[0157] ;in, In continuous time The quality of oils that have not yet been extracted from the system.

[0158] The calculation of the cumulative oil extraction efficiency based on the ratio of cumulative oil mass to the theoretically extractable total oil mass, and the setting of time boundary conditions for continuous process operation based on the solvent spraying cycle and the time interval between two adjacent feeds, specifically include:

[0159] Under the condition that both the theoretically extractable total mass of oil and the cumulative oil mass obtained through drainage are greater than the initial mass base, the cumulative oil extraction efficiency of the entire system at any time is calculated by comparing the ratio between the two and according to the ratio of the cumulative oil mass to the theoretically extractable total mass of oil.

[0160] In continuous feed control, the time interval between two adjacent feed operations is set and set to a value greater than the solvent spraying cycle. The time interval between two adjacent feed operations serves as the time boundary condition for continuous process operation, while ensuring a stable time relationship between the feed action, solvent spraying, and draining actions.

[0161] exist and Under the given conditions, the extraction efficiency is calculated as follows:

[0162] ;in, In continuous time The cumulative oil extraction efficiency of the entire system;

[0163] Set the time interval between two adjacent feeding operations in continuous feed control. And satisfy .

[0164] It should be noted that, in this document, relational terms such as "first" and "second" are used only 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 process, method, article, or apparatus.

[0165] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for deep and continuous extraction of high-quality Antarctic krill oil, characterized in that, include: Obtain the dimensions of the desorption tower and the preset mass ratio, and set the feeding method and mass flow rate of the mixed slurry; A pulse jet system is installed at the top of the desorption tower. The nozzle arrangement, jet cycle and duration are set. The instantaneous ejection velocity change law at the nozzle outlet is given in the control program and the single jet volume is recorded. A jet shear disturbance model was established inside the desorption tower. Based on the structure and the instantaneous ejection velocity change at the nozzle outlet, the shear rate at the characteristic position and the instantaneous acceleration of the instantaneous ejection velocity at the nozzle outlet were calculated. A particle cell disruption response model was established, and the degree of cell disruption was obtained based on particle properties and solvent flow and converted into the total rate of group oil release. The change in oil concentration in the solvent is obtained by accumulating the total oil release rate based on the total volume of solvent in the desorption tower, and an upper limit for solvent saturation judgment is established based on the upper limit of the saturated solubility concentration of Antarctic krill oil. The discharge and replenishment logic is constructed around the upper limit of solvent saturation. When the upper limit is reached, the solvent-oil phase mixture is discharged from the bottom and new solvent is added from the top. When the upper limit is not reached, the existing solvent state in the desorption tower is maintained. During continuous feeding and periodic drainage, the number of drainage times and variables are recorded. The cumulative oil mass obtained through drainage is calculated and compared with the total theoretically extractable oil mass entering the desorption tower to evaluate the residual oil mass. The cumulative oil extraction efficiency is calculated based on the ratio of the cumulative oil mass to the theoretically extractable total oil mass, and the time boundary conditions for continuous process operation are set according to the solvent spraying cycle and the time interval between two adjacent feeds.

2. The method for deep extraction and continuous extraction of high-quality Antarctic krill oil according to claim 1, characterized in that, The steps of obtaining the desorption tower body dimensions and preset mass ratio, and setting the feeding method and mass flow rate of the mixed slurry, specifically include: Obtain the height and inner diameter of the desorption tower body, and calculate the inner radius of the desorption tower body according to the cylindrical structure; The desorption tower body is constructed as a vertical cylindrical structure, and the effective internal volume of the desorption tower body is obtained based on the height and inner diameter of the desorption tower body according to the cylindrical volume calculation rules; Dehydrated krill powder and solvent are mixed at a preset mass ratio to form a fluid slurry. The preset mass ratio is recorded in the control parameters as the ratio of the mass of solvent to the mass of dehydrated krill powder. Given the total mass of the mixed slurry, calculate the mass of dehydrated krill powder and solvent in the mixed slurry according to the preset mass ratio, and use the calculation results as the loading amount of raw materials and solvent in the desorption tower. During the feeding stage, the mass flow rate of the mixed slurry pumped into the desorption tower per unit time is set, and the mass flow rate of the dehydrated krill powder entering the desorption tower per unit time is calculated according to the preset mass ratio. The calculated mass flow rate of the dehydrated krill powder is used as the infeed rate of the dehydrated krill powder.

3. The method for deep extraction and continuous extraction of high-quality Antarctic krill oil according to claim 2, characterized in that, The process of installing a pulse jet system at the top of the desorption tower, setting the nozzle arrangement, jet cycle, and duration, and providing the instantaneous ejection velocity variation law at the nozzle outlet and recording the single jet volume in the control program, specifically includes: A single-hole nozzle is installed at the center of the top of the desorption tower. The nozzle outlet orifice diameter is recorded and the geometric cross-sectional area of ​​the nozzle outlet is calculated based on the orifice diameter. In the control program, the solvent spraying cycle and the spraying duration within a single solvent spraying cycle are set so that the spraying duration is shorter than the solvent spraying cycle. Set time conversion rules in the control program to map the continuous running time to the conversion time range of a single solvent spraying cycle, and divide the spraying phase and the stop spraying phase in each solvent spraying cycle accordingly; The maximum ejection speed that the nozzle can achieve in a single solvent ejection cycle is obtained, and the instantaneous ejection speed at the nozzle outlet is adjusted according to a preset periodic change curve of first increasing and then decreasing during the ejection phase. During the stop-spray phase, the instantaneous ejection speed at the nozzle outlet is maintained at the initial value of the speed base. Based on the preset periodic change curve of first increasing and then decreasing and the geometric cross-sectional area of ​​the nozzle outlet, the instantaneous flow rate of the spraying stage is accumulated in time sequence to obtain the volume of solvent ejected from the nozzle in a single solvent spraying cycle. The volume of solvent ejected from the nozzle in a single solvent spraying cycle is taken as the single spray volume.

4. The method for deep extraction and continuous extraction of high-quality Antarctic krill oil according to claim 3, characterized in that, The establishment of the jet shear disturbance model within the desorption tower, and the calculation of the shear rate at characteristic locations and the instantaneous acceleration of the instantaneous jet velocity at the nozzle outlet based on the structure and the instantaneous jet velocity changes at the nozzle outlet, specifically includes: Based on the structure of the desorption tower and the flow characteristics of the nozzle jet after entering the desorption tower, the radial secondary turbulence formed by the jet in the desorption tower is taken as the shear disturbance object. A characteristic location is selected inside the desorption tower. Based on the instantaneous ejection velocity at the nozzle outlet and the dimensions of the desorption tower, the change of the local shear rate at the selected characteristic location over time is calculated according to the definition of shear rate in fluid mechanics. During the propagation of the jet along the axial direction of the desorption tower, the rate of change of the instantaneous ejection velocity at the nozzle outlet with time is obtained by subtracting the velocity change trend based on the curve of the instantaneous ejection velocity at the nozzle outlet with time. The rate of change of the instantaneous ejection velocity at the nozzle outlet with time is then used as the instantaneous acceleration of the instantaneous ejection velocity at the nozzle outlet.

5. The method for deep extraction and continuous extraction of high-quality Antarctic krill oil according to claim 4, characterized in that, The establishment of the particle cell disruption response model, which obtains the degree of cell disruption based on particle properties and solvent flow and converts it into the total rate of group oil release, specifically includes: The material density, characteristic diameter, and dynamic viscosity of the solvent of a single krill particle are obtained, and the time characteristic coefficients characterizing the shear response rate of the particle are obtained by combining the solvent shear field characteristics. By combining the time characteristic coefficients that characterize the shear response rate of particles with the local shear rate obtained in the shear perturbation model, the particle cell wall breakage response relationship is established, and the changes in the degree of cell wall breakage of individual particles and the degree of oil release completion with time under different shear intensities and cumulative shear action are obtained. Given the total number of krill particles participating in the current extraction process and the oil content of each particle, the oil release rate of each particle at the same time point is calculated based on the change in oil release completion over time. The oil release rates of all particles are added together to obtain the total rate of oil released into the solvent at the same time point.

6. The method for deep extraction and continuous extraction of high-quality Antarctic krill oil according to claim 5, characterized in that, The change in oil concentration in the solvent is obtained by accumulating the total oil release rate based on the total volume of solvent in the desorption tower, and an upper limit for solvent saturation is established based on the upper limit of the saturated solubility concentration of Antarctic krill oil. Specifically, this includes: Obtain the total volume of solvent in the desorption tower, and use the mass of oil per unit volume in the solvent as the oil concentration variable during operation; Based on the obtained total oil release rate, the mass of oil released within a given time interval will be evenly distributed into the total volume of solvent in the desorption tower. By accumulating the oil concentration increment within each time interval, the change of oil concentration in the solvent over time will be updated, and the oil concentration will be set as the initial value of the oil concentration at the initial moment. Under set temperature and pressure conditions, the upper limit of the saturated solubility concentration of the solvent for Antarctic krill oil is obtained, and the upper limit of the saturated solubility concentration of the solvent for Antarctic krill oil is used as the upper limit of solvent saturation judgment. When the calculated oil concentration reaches or exceeds the upper limit of solvent saturation judgment, the liquid discharge judgment logic is entered.

7. The method for deep extraction and continuous extraction of high-quality Antarctic krill oil according to claim 6, characterized in that, The discharge and replenishment logic is constructed around the upper limit of solvent saturation. When the upper limit is reached, the solvent-oil phase mixture is discharged from the bottom and new solvent is added from the top. When the upper limit is not reached, the existing solvent state in the desorption tower is maintained. Specifically, this includes: The discharge judgment logic is constructed based on the upper limit of solvent saturation judgment. The concentration of solvent grease in the desorption tower is checked at any time. When the grease concentration reaches or exceeds the upper limit of solvent saturation judgment, the discharge judgment logic is determined to be in the triggered state. When the grease concentration is lower than the upper limit of solvent saturation judgment, the discharge judgment logic is determined to be in the untriggered state. When the discharge judgment logic is triggered, a batch of solvent-oil phase mixture is discharged from the bottom of the desorption tower, and the volume of solvent-oil phase mixture corresponding to a single discharge is set to be the same as the total volume of solvent in the desorption tower. While discharging the solvent-oil phase mixture, a new solvent of the same volume and free of grease is added from the top of the desorption tower to keep the total volume of solvent in the desorption tower constant. Upon completion of replenishment, reset the solvent and grease concentration in the desorption tower to the initial base value and end the current drainage operation. During the period when the drain determination logic is not triggered, the drain operation will not be performed, and the existing solvent state in the desorption tower will be maintained.

8. The method for deep extraction and continuous extraction of high-quality Antarctic krill oil according to claim 7, characterized in that, The process of recording the number of drainage cycles during continuous feeding and periodic drainage, calculating the cumulative oil mass obtained through drainage, and comparing it with the theoretically extractable total oil mass entering the desorption tower to evaluate the residual oil quality, specifically includes: During continuous operation, a time axis is used as a reference to record the occurrence of each drainage action. A drainage count record variable is set, and the drainage count record variable is set as the initial value of the counting base at the initial moment. On the timeline, when the drainage judgment logic changes from an untriggered state to a triggered state, the value of the drainage count record variable is incremented by one, and the cumulative result of the drainage count record variable is maintained at subsequent times, so that the value of the drainage count record variable at any time is the cumulative value of all previous increment operations. Under the premise that the volume of solvent-oil phase mixture corresponding to a single drainage is fixed, the values ​​of the solvent saturation judgment upper limit, the volume of solvent-oil phase mixture corresponding to a single drainage, and the number of drainage records are multiplied to obtain the cumulative oil mass obtained through drainage up to any time. When the mass flow rate of dehydrated krill powder is kept constant, the mass flow rate of dehydrated krill powder, the mass fraction of oil in dehydrated krill powder, and the running time are used as parameters. The total mass of oil that can be theoretically completely extracted from the dehydrated krill powder entering the desorption tower at any time is calculated by the time accumulation method, and this total mass of oil is taken as the theoretical total mass of extractable oil. At any given time point, the total theoretically extractable oil mass is subtracted from the cumulative oil mass obtained through drainage, and the result is taken as the residual oil mass that has not yet been extracted in the system at the corresponding time point.

9. The method for deep extraction and continuous extraction of high-quality Antarctic krill oil according to claim 8, characterized in that, The calculation of the cumulative oil extraction efficiency based on the ratio of cumulative oil mass to the theoretically extractable total oil mass, and the setting of time boundary conditions for continuous process operation based on the solvent spraying cycle and the time interval between two adjacent feeds, specifically include: Under the condition that both the theoretically extractable total mass of oil and the cumulative oil mass obtained through drainage are greater than the initial mass base, the cumulative oil extraction efficiency of the entire system at any time is calculated by comparing the ratio between the two and according to the ratio of the cumulative oil mass to the theoretically extractable total mass of oil. In continuous feed control, the time interval between two adjacent feed operations is set and set to a value greater than the solvent spraying cycle. The time interval between two adjacent feed operations serves as the time boundary condition for continuous process operation, while ensuring a stable time relationship between the feed action, solvent spraying, and draining actions.

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