Whey powder preparation device with cooperation of spray drying and vibrated fluidized bed

Abstract

The invention is suitable for the technical field of dairy product processing, and provides a spray drying and vibrated fluidized bed synergetic whey powder preparation device which comprises a rack, and a pretreatment unit, a spray drying tower unit, a vibrated fluidized bed unit and a closed-loop air return unit which are fixedly mounted on the rack, the pretreatment unit is in sealed communication with the spray drying tower unit, the spray drying tower unit is in sealed communication with the vibrated fluidized bed unit, and the closed-loop air return unit is in bidirectional sealed communication with the exhaust ends and the air inlet ends of the units respectively; according to the method, low-temperature continuous preparation of the whey powder is realized through triple progressive structure collaboration, heat-sensitive nutritional ingredients of whey can be effectively reserved, the crystallinity of lactose is improved, the industrial pain point that a product is easy to cake is solved, meanwhile, the production energy consumption is greatly reduced, and the method is suitable for industrial resource utilization of a cheese byproduct whey liquid.

Description

Technical Field

[0001] This invention belongs to the field of dairy processing technology, and in particular relates to a whey powder preparation device that combines spray drying and vibrating fluidized bed. Background Technology

[0002] Whey is a major byproduct of cheese production, generating approximately 10 tons of whey liquid for every ton of cheese produced. Whey liquid is rich in nutrients such as lactose, whey protein, and minerals, and is widely recognized as a "nutritional treasure trove." Preparing whey powder to achieve high-value resource utilization of whey liquid aligns with the national industrial guidelines for circular economy and green, low-carbon development, while also addressing the environmental pollution and high processing costs associated with direct discharge of whey liquid. Currently, the industrial production of whey powder primarily employs a process combining high-temperature evaporation and concentration with spray drying. However, the supporting equipment suffers from the following significant technical deficiencies in practical applications: The raw material pretreatment process lacks a low-temperature integrated processing structure. Existing equipment mostly adopts a combination of high-temperature multi-effect evaporation and concentration at temperatures above 60°C and high-temperature instantaneous sterilization. Heat-sensitive whey proteins, vitamins, and other components in whey are prone to thermal denaturation and oxidative loss. The whey protein denaturation rate generally exceeds 15%, which significantly reduces the nutritional value of the product. At the same time, high-temperature concentration leads to excessive heat load in the subsequent drying process, resulting in high production energy consumption and making it impossible to achieve source control of raw material quality. The spray drying process uses a single high-temperature direct spray drying structure. The contact method between hot air and atomized liquid is unreasonable, the drying temperature control accuracy is poor, and the inlet air temperature generally exceeds 180℃. This not only further aggravates the deactivation of heat-sensitive components, but also leads to uneven drying rate of atomized droplets, powder particle size distribution width exceeding 40%, and amorphous lactose content exceeding 30%. This lays a core hidden danger for moisture absorption and clumping during the subsequent storage of the product, and makes it impossible to achieve quality control of the drying process. The synergy between spray drying and fluidized bed is merely a simple series structure, lacking a segmented structure for the coordinated processing of lactose crystallization, drying, and cooling. This makes it impossible to precisely control the temperature, holding time, and crystal form transformation process of lactose crystallization, resulting in finished lactose with a crystallinity generally below 70%, high hygroscopicity, and a tendency to clump during storage and transportation, leading to poor product flowability and solubility. Furthermore, the existing equipment lacks a closed-loop return air structure, with direct hot air exhaust resulting in a waste heat recovery rate of less than 30%, high production energy consumption, and an inability to achieve quality standardization and energy conservation in the final product. Therefore, a whey powder preparation device that combines spray drying and vibrating fluidized bed is needed to solve the above problems. Summary of the Invention

[0003] The purpose of this invention is to provide a whey powder preparation apparatus that combines spray drying and vibrating fluidized bed to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A whey powder preparation apparatus combining spray drying and vibrating fluidized bed includes a frame, and a pretreatment unit, a spray drying tower unit, a vibrating fluidized bed unit and a closed-loop return air unit fixedly installed on the frame; The discharge end of the pretreatment unit is sealed and connected to the top feed end of the spray drying tower unit through a high-pressure conveying pipeline; The cone-bottom discharge port of the spray drying tower unit is sealed and connected to the inlet port at the beginning of the vibrating fluidized bed unit. The air inlet of the closed-loop return air unit is sealed and connected to the exhaust end of the top of the spray drying tower unit and the exhaust end of the vibrating fluidized bed unit, respectively. The air outlet of the closed-loop return air unit is sealed and connected to the air inlet of the tower body of the spray drying tower unit and the air inlet of the bed body of the vibrating fluidized bed unit, respectively. An integrated preparation system encompassing pretreatment, low-temperature spray drying, segmented fluidized bed shaping, and closed-loop waste heat recovery was constructed, breaking through the technical bottleneck of independent operation and poor coordination of traditional units. Through the fully sealed connection of the four major units, a fully enclosed continuous production process of whey from raw materials to finished product was achieved, avoiding microbial contamination and nutrient loss during material transfer. Meanwhile, the bidirectional connection design of the closed-loop return air unit realizes the full-process recovery and utilization of exhaust waste heat, solving the problems of high energy consumption and thermal pollution caused by direct exhaust of traditional devices. It provides basic structural support for triple progressive quality control, can be adapted to whey raw materials with different solid contents, and has strong versatility and industrialization promotion value.

[0005] In a further technical solution, the pretreatment unit includes a raw material buffer tank, a low-temperature nanofiltration concentration component, a low-temperature pasteurizer, and a high-pressure feed pump that are sequentially sealed and connected. The concentrated liquid outlet of the low-temperature nanofiltration concentration component is connected to the inlet of the low-temperature pasteurizer, the outlet of the low-temperature pasteurizer is connected to the inlet of the high-pressure feed pump, and the outlet of the high-pressure feed pump is the outlet of the pretreatment unit. The pretreatment unit series structure realizes integrated low-temperature concentration and sterilization of whey, which is the core structure of the first progressive quality control of this invention. The raw material buffer tank can realize constant temperature buffering and homogenization of raw materials at 10-15℃, avoiding raw material sedimentation and stratification, and ensuring the stability of feed quality. The low-temperature nanofiltration concentration component completes the pre-concentration and desalination of whey under low temperature conditions, replacing the traditional high-temperature evaporation concentration, and can accurately control the solid content of whey to the target range of 30%-45%, while controlling the denaturation rate of heat-sensitive whey protein at an extremely low level. The low-temperature pasteurizer realizes low-temperature sterilization, and with the constant pressure delivery of 10-15MPa by the high-pressure feed pump, it provides stable and high-quality raw materials for subsequent spray drying, ensuring the nutritional activity and quality consistency of the finished product from the source.

[0006] A further technical solution is provided, wherein the spray drying tower unit includes a vertical tower body, a centrifugal atomizer, a low-temperature cyclone air inlet assembly, and a cyclone separator; the centrifugal atomizer is fixedly installed at the top center of the vertical tower body, and the feed inlet of the centrifugal atomizer is the feed end of the spray drying tower unit; the low-temperature cyclone air inlet assembly is fixedly installed on the upper side wall of the vertical tower body and is evenly distributed along the circumference of the vertical tower body; the feed inlet of the cyclone separator is sealed and connected to the exhaust end of the top of the vertical tower body, the solid phase outlet of the cyclone separator is sealed and connected to the discharge port at the bottom of the vertical tower body, and the gas phase outlet of the cyclone separator is the exhaust end of the spray drying tower unit; The spray drying tower unit structure enables low-temperature cyclone fractional drying of whey concentrate and is the core structure of the second progressive quality control mechanism of this invention. The centrifugal atomizer atomizes the concentrated whey into uniform 30-100μm micron-sized droplets, ensuring sufficient contact between the droplets and hot air. The vertical tower provides a closed, Class 10,000 cleanroom for the drying process, preventing external contamination. The low-temperature cyclone inlet assembly creates a uniform and stable cyclone airflow field within the tower, achieving uniform-speed fractional drying of the atomized droplets. The cyclone separator efficiently recovers fine powder from the exhaust air, with a separation efficiency ≥98%, avoiding material waste and ensuring exhaust air cleanliness. This provides a foundation for subsequent closed-loop return air waste heat recovery, reducing the deactivation of heat-sensitive components and the formation of amorphous lactose during the drying process.

[0007] A further technical solution is that the low-temperature swirl air inlet assembly includes at least 3 sets of swirl air inlet nozzles, the air outlet direction of each set of swirl air inlet nozzles is parallel to the tangential direction of the inner wall of the vertical tower, and the air outlet swirl direction of all swirl air inlet nozzles is consistent. The arrangement of the swirl inlet nozzles is the core guarantee for achieving uniform low-temperature swirl drying. At least three sets of tangentially arranged swirl inlets can form a ring-shaped swirl air field with consistent swirl direction and uniform wind speed within the vertical tower, avoiding the problems of localized high temperature and uneven hot air distribution caused by traditional direct injection structures. The tangential air outlet design can extend the residence time of atomized droplets in the tower, ensuring that the droplets are fully dried at a low temperature of 120-150℃, avoiding the problem of droplets settling and sticking to the wall before they are completely dried. At the same time, the uniform swirl air field can precisely control the settling path of powder particles, making the particle size distribution deviation of the finished product ≤15%, significantly reducing the proportion of amorphous lactose, and fundamentally reducing the risk of subsequent product agglomeration.

[0008] A further technical solution is provided, wherein the vibrating fluidized bed unit includes a horizontal bed body, a vibration drive assembly, an air distribution plate, and segmented air chambers; the horizontal bed body is fixedly installed on the frame by shock-absorbing springs, and the vibration drive assembly is fixedly installed on the feed end side wall of the horizontal bed body; the air distribution plate is horizontally fixed in the inner cavity of the horizontal bed body, dividing the inner cavity of the horizontal bed body into an upper material cavity and a lower air chamber cavity; the segmented air chambers are arranged in the lower air chamber cavity, and are sequentially divided into a crystallization heat preservation air chamber, a drying air chamber, and a cooling air chamber along the material conveying direction of the horizontal bed body; The vibrating fluidized bed unit structure enables segmented crystallization-drying-cooling synergistic processing of whey powder, and is the core structure of the third progressive quality control mechanism of this invention. The horizontal bed body is mounted with shock-absorbing springs, reducing the impact of vibration on the frame and ensuring operational stability. The vibration drive component provides a stable excitation force, causing the material to jump forward at a uniform speed along the air distribution plate, ensuring full contact between the material and hot air while preventing material accumulation. The air distribution plate achieves uniform airflow distribution, and the segmented air chambers are divided into three independent functional sections along the material conveying direction, enabling continuous processing of lactose crystallization insulation, deep drying, and cooling and shaping. This breaks the limitations of traditional single-function fluidized beds and provides a structural basis for precise control of lactose crystal form.

[0009] In a further technical solution, the tops of the crystallization insulation air chamber, the drying air chamber and the cooling air chamber are respectively connected to the corresponding areas of the air distribution plate, and each air chamber is provided with an independent air inlet and a PT100 temperature control component on its side wall. Each air inlet is sealed and connected to the air outlet of the closed-loop return air unit. The segmented, independently adjustable air chamber structure is the core guarantee for achieving precise control of lactose crystal form. Each of the three air chambers is connected to a corresponding area of ​​the air distribution plate, ensuring independent airflow for each functional section, avoiding crosstalk between airflows at different temperatures, and guaranteeing the stability of process parameters in each section. Independent air inlets and PT100 temperature control components provide temperature control accuracy up to ±0.5℃, allowing for precise adjustment of the inlet air temperature, velocity, and volume of each air chamber according to process requirements. This enables precise control of lactose crystallization temperature and holding time, promoting the stable conversion of α-lactose to β-lactose and significantly improving lactose crystallinity. Simultaneously, each air chamber is connected to a closed-loop return air unit, enabling the graded recovery and utilization of waste heat, further reducing production energy consumption and ensuring consistent finished product quality.

[0010] A further technical solution is that the closed-loop return air unit includes a pulse-jet bag filter, a surface cooler, a steam heater, and a variable frequency centrifugal fan that are sequentially sealed and connected; the air inlet of the pulse-jet bag filter is the air inlet end of the closed-loop return air unit, and the air outlet of the variable frequency centrifugal fan is the air outlet end of the closed-loop return air unit. The closed-loop return air unit structure realizes dust removal, temperature control, and waste heat recovery and recycling of exhaust air, which is the core structure of this invention for achieving energy saving and consumption reduction. The pulse-jet bag filter can efficiently remove fine powder from the exhaust air, with a dust removal efficiency of over 99.9%, ensuring the cleanliness of the circulating air and avoiding wear and secondary pollution of subsequent equipment and products by fine powder. The surface cooler and steam heater work together to precisely control the temperature of the circulating air according to the process requirements of different units, with a temperature control accuracy of ±1℃, meeting the air temperature requirements of different stages such as spray drying, crystallization insulation, drying, and cooling. The variable frequency centrifugal fan can precisely control the circulating air volume and air pressure to adapt to the needs of different production loads, while reducing the energy consumption of the fan operation. The fully closed-loop structural design can increase the exhaust waste heat recovery rate to over 85%, significantly reducing the steam and electricity consumption in the production process and meeting the requirements of green and low-carbon production.

[0011] A further technical solution is that the low-temperature nanofiltration concentration component includes a nanofiltration membrane group and a reverse osmosis membrane group connected in series. The molecular weight cutoff of the nanofiltration membrane group is 200-1000 Da, and the operating pressure of the nanofiltration membrane group and the reverse osmosis membrane group is 1.0-2.5 MPa, and the operating temperature range is 10-20℃. The low-temperature nanofiltration concentration module structure is the core guarantee for achieving low-temperature pretreatment of raw materials. The series-connected nanofiltration and reverse osmosis membrane modules enable fractional concentration and desalination of whey. The nanofiltration membrane modules, with a molecular weight cutoff of 200-1000 Da, can precisely retain whey protein and macromolecular nutrients while removing monovalent salts and small-molecule impurities, thus preparing desalted whey powder. An operating pressure of 1.0-2.5 MPa ensures stable membrane flux and avoids membrane fouling. The operating temperature range of 10-20℃ completely avoids the thermal denaturation temperature of whey protein, maximizing the retention of heat-sensitive nutrients in the whey while preventing membrane pore blockage caused by low temperatures and lactose browning caused by high temperatures. Compared with traditional high-temperature evaporation and concentration, this structure reduces energy consumption by more than 60% and significantly reduces the heat load of subsequent drying processes, improving production efficiency.

[0012] In a further technical solution, the air distribution plate is provided with air distribution holes of different diameters corresponding to the crystallization insulation air chamber, drying air chamber, and cooling air chamber. The diameters of the air distribution holes are 2mm, 1.5mm, and 1mm, respectively, and the opening ratio of the air distribution holes decreases sequentially along the material conveying direction, with opening ratios of 10%, 6%, and 2%, respectively. The variable aperture and opening ratio structure of the air distribution plate is the core optimized structure for achieving segmented precision processing. Different apertures and opening ratios are set in the air distribution plate areas corresponding to the three functional air chambers, precisely adapting to the different material states and process requirements of each segment: the large aperture and high opening ratio design in the crystallization and insulation section provides a large air volume and a low fluidization velocity, keeping the material in a stable bubbling fluidization state, ensuring the constant temperature residence time required for lactose crystallization, and avoiding material channeling; the medium aperture and medium opening ratio design in the drying section provides a moderate fluidization velocity, enhancing the mass and heat transfer efficiency between the material and hot air, achieving efficient deep drying; the small aperture and low opening ratio design in the cooling section provides a high fluidization velocity, achieving rapid cooling and shaping of the material, preventing lactose crystal reversal. This structure ensures stable fluidization of the material in each functional segment, improving processing efficiency and finished product quality.

[0013] A further technical solution is provided whereby a sealing and air-locking discharge valve is installed between the cone bottom discharge port of the spray drying tower unit and the feed port of the vibrating fluidized bed unit. The feed port of the sealing and air-locking discharge valve is connected to the cone bottom discharge port flange of the vertical tower body, and the discharge port of the sealing and air-locking discharge valve is connected to the first end feed port flange of the horizontal bed body. The sealed, airtight unloading valve is a key connection structure ensuring the coordinated operation of the two core units. The flange connection guarantees food-grade sealing at the connection points, preventing material leakage and external microbial contamination, while also facilitating equipment installation, disassembly, and maintenance. The sealed, airtight unloading valve enables continuous and uniform unloading, ensuring a stable material flow rate into the fluidized bed and preventing uneven processing caused by material accumulation. Simultaneously, it completely isolates the airflow within the tower and the bed, preventing crosstalk between the hot air from the spray drying tower and the airflow from the fluidized bed. This ensures stable and controllable process parameters for both units, prevents a decrease in drying efficiency due to negative pressure imbalance within the tower, and further improves the stability of the unit's operation and the consistency of the finished product quality.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention achieves the first level of quality control at the source by connecting a low-temperature nanofiltration concentration component and a low-temperature pasteurizer in a series structure within the pretreatment unit. It replaces traditional high-temperature evaporation with a 10-20℃ low-temperature nanofiltration + reverse osmosis membrane concentration process, precisely controlling the whey solids content and desalting while keeping the whey protein denaturation rate below 3%, maximizing the preservation of the raw material's nutritional activity. Combined with 72℃ / 15s low-temperature pasteurization to achieve aseptic treatment, it simultaneously increases the whey solids content to 30%-45%, significantly reducing the subsequent drying heat load and reducing production energy consumption from the source. This invention achieves a second layer of process quality control through the synergistic structure of a low-temperature swirl air inlet assembly and a centrifugal atomizer in a spray drying tower unit. Tangential swirl air inlets, evenly distributed along the circumference of the tower, create a uniform and stable low-temperature swirl air field within the tower, ensuring thorough and uniform contact between the atomized droplets and hot air. This achieves uniform, graded drying and avoids protein denaturation and charring caused by localized high temperatures. The finished product particle size distribution deviation is ≤15%, and the proportion of amorphous lactose is reduced to less than 10%, minimizing the core factors that induce product agglomeration during the process and providing a homogeneous material basis for subsequent lactose crystallization. This invention achieves third-stage final quality control and energy saving through the synergistic effect of a segmented air chamber structure in a vibrating fluidized bed unit and a closed-loop return air unit. Three independent temperature-controlled air chambers, arranged along the material conveying direction, precisely regulate the air temperature and velocity in each section, allowing the material to sequentially complete constant-temperature crystallization, deep drying, and cooling and shaping of lactose. The finished lactose has a crystallinity of ≥92%, fundamentally solving the problem of moisture absorption and clumping, and improving product flowability and solubility. Combined with closed-loop return air, waste heat recovery is achieved, with a waste heat recovery rate of ≥85%, reducing production energy consumption by more than 40% compared to traditional equipment.

[0015] To more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the overall architecture of the present invention; Figure 2 This is a schematic diagram of the preprocessing unit of the present invention; Figure 3 This is a schematic diagram of the overall structure of the spray drying tower unit of the present invention; Figure 4 This is a schematic diagram of the structure of the low-temperature swirl air inlet assembly of the present invention; Figure 5 This is a schematic diagram of the overall structure of the vibrating fluidized bed unit of the present invention; Figure 6 This is a schematic diagram of the structural connection of the segmented air chamber of the present invention; Figure 7 This is a schematic diagram of the closed-loop return air unit of the present invention; Figure 8 This is a schematic diagram of the structural connection of the nanofiltration module of the present invention; Figure 9 This is a schematic diagram of the air distribution of the air distribution plate of the present invention; Figure 10 This is a schematic diagram of the structural connection of the sealing airlock unloading valve of the present invention.

[0017] In the diagram: 1. Frame; 2. Pretreatment unit; 21. Raw material buffer tank; 22. Low-temperature nanofiltration concentration module; 221. Nanofiltration membrane module; 222. Reverse osmosis membrane module; 23. Low-temperature pasteurizer; 24. High-pressure feed pump; 3. Spray drying tower unit; 31. Vertical tower body; 32. Centrifugal atomizer; 33. Low-temperature cyclone air inlet module; 331. Cyclone air inlet nozzle; 34. Cyclone separator; 4. Vibrating fluidized bed unit; 41. Horizontal bed body; 42. Vibration drive module; 43. Air distribution plate; 44. Segmented air chamber; 441. Crystallization insulation air chamber; 442. Drying air chamber; 443. Cooling air chamber; 5. Closed-loop return air unit; 51. Pulse bag filter; 52. Surface cooler; 53. Steam heater; 54. Variable frequency centrifugal fan; 6. Sealed airlock discharge valve. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] The specific implementation of the present invention will be described in detail below with reference to specific embodiments. Example

[0020] like Figure 1-10As shown, this embodiment of the invention provides a whey powder preparation device that combines spray drying and vibrating fluidized bed, including a frame 1, and a pretreatment unit 2, a spray drying tower unit 3, a vibrating fluidized bed unit 4, and a closed-loop return air unit 5 fixedly installed on the frame 1; The discharge end of the pretreatment unit 2 is sealed and connected to the top feed end of the spray drying tower unit 3 through a food-grade high-pressure conveying pipeline; The cone bottom discharge port of spray drying tower unit 3 is sealed and connected to the first end feed port of vibrating fluidized bed unit 4 through a sealed airlock discharge valve 6. The air inlet of the closed-loop return air unit 5 is sealed and connected to the exhaust end of the top of the spray drying tower unit 3 and the exhaust end of the vibrating fluidized bed unit 4, respectively. The air outlet of the closed-loop return air unit 5 is sealed and connected to the air inlet of the tower body of the spray drying tower unit 3 and the air inlet of the bed body of the vibrating fluidized bed unit 4, respectively.

[0021] In this embodiment, the pretreatment unit 2 includes a raw material buffer tank 21, a low-temperature nanofiltration concentration component 22, a low-temperature pasteurizer 23, and a high-pressure feed pump 24 that are sealed and connected in sequence. The spray drying tower unit 3 includes a vertical tower body 31, a centrifugal atomizer 32, a low-temperature cyclone air inlet assembly 33 and a cyclone separator 34. The low-temperature cyclone air inlet assembly 33 is provided with 4 sets of cyclone air inlet nozzles 331, which are evenly arranged around the circumference of the vertical tower body 31. The air outlet direction of each set of cyclone air inlet nozzles 331 is parallel to the tangential direction of the inner wall of the tower and the cyclone direction is consistent. The vibrating fluidized bed unit 4 includes a horizontal bed body 41, a vibration drive assembly 42, an air distribution plate 43, and a segmented air chamber 44. The segmented air chamber 44 is divided into a crystallization heat preservation air chamber 441, a drying air chamber 442, and a cooling air chamber 443 along the material conveying direction. The closed-loop return air unit 5 includes a pulse-type bag filter 51, a surface cooler 52, a steam heater 53, and a variable frequency centrifugal fan 54, which are sequentially sealed and connected.

[0022] This embodiment is a basic collaborative device adapted to the whey processing needs of small and medium-sized cheese production lines. The daily whey processing capacity is 50 tons, and the finished whey powder meets the requirements of GB11674-2010 standard. Example

[0023] The difference between this embodiment and Embodiment 1 is that the low-temperature nanofiltration concentration component 22 uses two sets of nanofiltration membrane modules 221 connected in series and two sets of reverse osmosis membrane modules 222 connected in series. The nanofiltration membrane module 221 has a molecular weight cutoff of 200-1000 Da, the membrane module operating pressure is 1.5-2.5 MPa, and the operating temperature is controlled at 10-20℃. The side walls of the crystallization insulation air chamber 441, the drying air chamber 442 and the cooling air chamber 443 are all equipped with independent air inlets and PT100 temperature control components. Each air inlet is sealed and connected to the air outlet of the closed-loop return air unit 5. The air distribution plate 43 is provided with air distribution holes of different diameters in the areas corresponding to the three air chambers. The hole diameters are 2mm, 1.5mm and 1mm respectively, and the opening rate decreases sequentially along the material conveying direction, which are 10%, 6% and 2% respectively. The length of the crystallization insulation air chamber 441 accounts for 40% of the total length of the horizontal bed 41.

[0024] In this embodiment, the optimized membrane module can accurately achieve graded desalting and concentration of whey, and retain heat-sensitive nutrients to the maximum extent under low temperature conditions; the independent PT100 temperature control components of each air chamber can achieve a temperature control accuracy of ±0.5℃, accurately matching the temperature requirements of each stage of lactose crystallization, drying and cooling; the variable pore size and opening ratio air distribution plate can ensure the stability of the fluidization state of the material in each functional section, extend the residence time in the crystallization heat preservation section and improve the uniformity of lactose crystallization.

[0025] This embodiment is an optimized device that fully matches the applicant's existing 12-ton / day cheese production line (130 tons of whey liquid per day) capacity requirements. The finished product has a whey protein denaturation rate of ≤3%, lactose crystallinity of ≥92%, and no clumping after 6 months of storage. Example

[0026] The difference between this embodiment and embodiment 2 is that an intelligent measurement and control unit is added to each unit of the device. The intelligent measurement and control unit includes a PLC controller, and a PT100 temperature sensor, pressure sensor, electromagnetic flow sensor, online near-infrared moisture detector and online laser particle size analyzer respectively installed in each unit. A plate-type waste heat recovery heat exchanger is added between the surface cooler 52 and the cyclone separator 34 of the closed-loop return air unit 5. The refrigerant side of the waste heat recovery heat exchanger is connected to the heat exchange pipeline of the low-temperature pasteurizer 23. Vibration drive assembly 42 adopts a variable frequency vibration motor with a vibration frequency adjustment range of 15-50Hz; A food-grade lactose seed additive component was added between the low-temperature pasteurizer 23 and the high-pressure feed pump 24.

[0027] In this embodiment, the intelligent measurement and control unit can collect process parameters throughout the entire process in real time and realize automated closed-loop control through the PLC controller to ensure that the quality deviation between batches of finished products is ≤2%; the added plate waste heat recovery heat exchanger can further recover exhaust waste heat for heat exchange and heating of the low-temperature pasteurizer, increasing the waste heat recovery rate to over 90%; the variable frequency vibration motor can precisely adjust the vibration frequency and amplitude according to the material flow rate to avoid material accumulation or excessive conveying speed; the lactose seed addition component can precisely add 0.1%-0.3% lactose seed to provide uniform crystal nuclei for the crystallization process, further shortening the crystallization time and improving crystallization consistency.

[0028] This embodiment is an intelligent fully closed-loop device that can realize fully automated continuous production of whey powder, adapting to the intelligent production needs of modern dairy processing plants.

[0029] Working principle and usage process of this invention: The whey powder preparation apparatus of the present invention, which combines spray drying and vibrating fluidized bed, operates continuously according to the following process flow. The process parameters throughout the entire process are reasonably matched, without any fundamental contradictions, and fully comply with the standards for industrialized dairy production: Raw material pretreatment stage: Whey liquor, a byproduct of cheese production, is fed into raw material buffer tank 21. After constant temperature buffering and homogenization at 10-15℃, it is pumped into low-temperature nanofiltration concentration module 22. Under operating conditions of 10-20℃ and 1.0-2.5MPa, it undergoes graded pre-concentration and desalting through nanofiltration membrane module 221 and reverse osmosis membrane module 222 connected in series, removing some water and monovalent salts from the whey liquor to obtain concentrated whey liquor with a solid content of 30%-45%. The concentrated whey liquor is then fed into low-temperature pasteurizer 23, where it undergoes aseptic treatment using a low-temperature pasteurization process at 72℃ / 15s. This process kills pathogenic and spoilage bacteria while maximizing the preservation of the activity of heat-sensitive nutrients. After sterilization, the concentrated whey liquor is pressurized to 10-15MPa by high-pressure feed pump 24 and then sent to centrifugal atomizer 32 of spray drying tower unit 3 via food-grade high-pressure pipeline.

[0030] Low-temperature spray drying stage: The concentrated whey liquid is centrifuged and atomized at high speed (15000-20000 r / min) by centrifugal atomizer 32 to form uniform 30-100 μm micron-sized droplets, which are vertically sprayed into the inner cavity of the vertical tower body 31; at the same time, the 120-150℃ low-temperature hot air delivered by the closed-loop return air unit 5 is sent into the tower through multiple sets of tangential swirl air inlets 331 of the low-temperature swirl air inlet assembly 33, forming a uniform low-temperature swirl air field with consistent swirl direction inside the tower; the atomized droplets are in full contact with the hot air in the swirl air field, and are uniformly dried. The surface moisture is quickly evaporated and initially dried to form primary whey powder particles with a moisture content of 8%-12%. This moisture range ensures that lactose molecules have sufficient migration fluidity, providing the necessary kinetic conditions for subsequent crystallization. The primary particles that settle to the bottom of the tower cone are continuously and uniformly fed into the vibrating fluidized bed unit 4 through the sealed airlock discharge valve 6. The exhaust air carrying fine powder at the top of the tower is sent to the cyclone separator 34 with a separation efficiency of ≥98%. The separated fine powder flows into the discharge port at the bottom of the cone, and the separated exhaust air is sent to the closed-loop return air unit 5 for treatment.

[0031] Segmented crystallization-drying-cooling stage: After the primary whey powder particles enter the material chamber of the horizontal bed 41, they move at a constant speed towards the discharge end along the air distribution plate 43 under the excitation force of the vibration drive component 42; the temperature-controlled air conveyed by the closed-loop return air unit 5 is sent into the crystallization insulation air chamber 441, drying air chamber 442 and cooling air chamber 443 of the segmented air chamber 44, and is evenly fed into the material layer through the air distribution holes of the air distribution plate 43, making full contact with the material: the material first enters the crystallization insulation section, and is kept at a constant temperature of 18-22℃ for 20-30 minutes. This temperature is the lactose α / The optimal thermodynamic range for β-crystal equilibrium transformation promotes the conversion of α-lactose to stable β-lactose, completing the pre-crystallization process of lactose. It then enters the drying section, where deep drying is achieved under hot air at 50-70℃, controlling the product's moisture content to within 3% as required by GB11674-2010 standards. Finally, it enters the cooling section, where it is rapidly cooled to room temperature by cold air at 10-15℃, completing the crystal form fixation and preventing clumping caused by crystal reversal during storage. The processed finished whey powder is discharged from the outlet end of the horizontal bed 41 for subsequent aseptic packaging.

[0032] Closed-loop return air stage: The exhaust air from the spray drying tower unit 3 and the vibrating fluidized bed unit 4 is first sent to the pulse bag dust collector 51 of the closed-loop return air unit 5 to remove fine powder from the exhaust air. The dust removal efficiency can reach more than 99.9%. The clean exhaust air after dust removal is sent to the surface cooler 52 and the steam heater 53 for precise temperature control. The temperature is adjusted to the target temperature according to the air supply requirements of different units. After being pressurized by the variable frequency centrifugal fan 54, it is sent to the spray drying tower unit 3 and the vibrating fluidized bed unit 4 for recycling. This achieves efficient recovery and utilization of exhaust waste heat and significantly reduces the consumption of steam and electricity in the production process.

[0033] The circuits, electronic components, and modules involved are all existing technologies, which can be fully implemented by those skilled in the art, and need not be elaborated upon. The content protected by this invention does not involve any improvement to the software and methods.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A whey powder preparation apparatus combining spray drying and vibrating fluidized bed, characterized in that: It includes a frame (1), and a pretreatment unit (2), a spray drying tower unit (3), a vibrating fluidized bed unit (4), and a closed-loop return air unit (5) fixedly installed on the frame (1); The discharge end of the pretreatment unit (2) is sealed and connected to the top feed end of the spray drying tower unit (3) through a high-pressure conveying pipeline; The cone bottom outlet of the spray drying tower unit (3) is sealed and connected to the inlet at the head end of the vibrating fluidized bed unit (4); The air inlet of the closed-loop return air unit (5) is sealed and connected to the exhaust end of the top of the spray drying tower unit (3) and the exhaust end of the vibrating fluidized bed unit (4), respectively. The air outlet of the closed-loop return air unit (5) is sealed and connected to the air inlet of the tower body of the spray drying tower unit (3) and the air inlet of the bed body of the vibrating fluidized bed unit (4), respectively.

2. The whey powder preparation apparatus combining spray drying and vibrating fluidized bed according to claim 1, characterized in that: The pretreatment unit (2) includes a raw material buffer tank (21), a low-temperature nanofiltration concentration component (22), a low-temperature pasteurizer (23), and a high-pressure feed pump (24) that are sealed and connected in sequence. The concentrated liquid outlet of the low-temperature nanofiltration concentration component (22) is connected to the feed inlet of the low-temperature pasteurizer (23), the discharge outlet of the low-temperature pasteurizer (23) is connected to the feed inlet of the high-pressure feed pump (24), and the discharge outlet of the high-pressure feed pump (24) is the discharge end of the pretreatment unit (2).

3. The whey powder preparation apparatus combining spray drying and vibrating fluidized bed according to claim 1, characterized in that: The spray drying tower unit (3) includes a vertical tower body (31), a centrifugal atomizer (32), a low-temperature cyclone air inlet assembly (33), and a cyclone separator (34). The centrifugal atomizer (32) is fixedly installed at the top center of the vertical tower body (31), and the feed inlet of the centrifugal atomizer (32) is the feed end of the spray drying tower unit (3); The low-temperature swirl air inlet assembly (33) is fixedly installed on the upper side wall of the vertical tower body (31) and is evenly arranged along the circumference of the vertical tower body (31). The feed inlet of the cyclone separator (34) is sealed and connected to the exhaust end of the top of the vertical tower (31), the solid phase outlet of the cyclone separator (34) is sealed and connected to the discharge port at the bottom of the cone of the vertical tower (31), and the gas phase outlet of the cyclone separator (34) is the exhaust end of the spray drying tower unit (3).

4. The whey powder preparation apparatus combining spray drying and vibrating fluidized bed according to claim 3, characterized in that: The low-temperature swirl air inlet assembly (33) includes at least 3 sets of swirl air inlet nozzles (331). The air outlet direction of each set of swirl air inlet nozzles (331) is parallel to the tangential direction of the inner wall of the vertical tower body (31), and the air outlet swirl direction of all swirl air inlet nozzles (331) is consistent.

5. The whey powder preparation apparatus combining spray drying and vibrating fluidized bed according to claim 1, characterized in that: The vibrating fluidized bed unit (4) includes a horizontal bed body (41), a vibration drive assembly (42), an air distribution plate (43), and a segmented air chamber (44). The horizontal bed (41) is fixedly installed on the frame (1) by shock-absorbing springs, and the vibration drive assembly (42) is fixedly installed on the feed end side wall of the horizontal bed (41); The air distribution plate (43) is horizontally fixed to the inner cavity of the horizontal bed (41), dividing the inner cavity of the horizontal bed (41) into an upper material cavity and a lower air chamber cavity. The segmented air chamber (44) is located in the lower air chamber cavity and is sequentially divided into a crystallization heat preservation air chamber (441), a drying air chamber (442) and a cooling air chamber (443) along the material conveying direction of the horizontal bed (41).

6. The whey powder preparation apparatus combining spray drying and vibrating fluidized bed according to claim 5, characterized in that: The tops of the crystallization insulation air chamber (441), the drying air chamber (442) and the cooling air chamber (443) are respectively connected to the corresponding areas of the air distribution plate (43), and each air chamber has an independent air inlet and a PT100 temperature control component on its side wall. Each air inlet is sealed and connected to the air outlet of the closed-loop return air unit (5).

7. The whey powder preparation apparatus combining spray drying and vibrating fluidized bed according to claim 1, characterized in that: The closed-loop return air unit (5) includes a pulse-type bag filter (51), a surface cooler (52), a steam heater (53), and a variable frequency centrifugal fan (54) that are sequentially sealed and connected. The air inlet of the pulse bag filter (51) is the air inlet of the closed-loop return air unit (5), and the air outlet of the variable frequency centrifugal fan (54) is the air outlet of the closed-loop return air unit (5).

8. The whey powder preparation apparatus according to claim 2, characterized in that: The low-temperature nanofiltration concentration module (22) includes a nanofiltration membrane group (221) and a reverse osmosis membrane group (222) connected in series. The nanofiltration membrane group (221) has a molecular weight cutoff of 200-1000 Da. The operating pressure of the nanofiltration membrane group (221) and the reverse osmosis membrane group (222) is 1.0-2.5 MPa, and the operating temperature range is 10-20℃.

9. The whey powder preparation apparatus combining spray drying and vibrating fluidized bed according to claim 5, characterized in that: The air distribution plate (43) is provided with air distribution holes of different diameters in the areas corresponding to the crystallization heat preservation air chamber (441), the drying air chamber (442), and the cooling air chamber (443). The diameters of the air distribution holes are 2mm, 1.5mm, and 1mm respectively, and the opening rate of the air distribution holes decreases sequentially along the material conveying direction, with the opening rates being 10%, 6%, and 2% respectively.

10. The whey powder preparation apparatus according to claim 1, characterized in that: A sealing airlock discharge valve (6) is provided between the cone bottom discharge port of the spray drying tower unit (3) and the feed port of the vibrating fluidized bed unit (4). The feed port of the sealing airlock discharge valve (6) is connected to the cone bottom discharge port flange of the vertical tower body (31), and the discharge port of the sealing airlock discharge valve (6) is connected to the first end feed port flange of the horizontal bed body (41).

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