Process and device for preparing soybean protein by granulating soybean meal fine powder

Abstract

The invention relates to a process and a device for preparing soybean protein by granulating soybean meal fine powder, and belongs to the field of food processing. According to the technical scheme, the technology for preparing the soybean protein through soybean meal fine powder granulation comprises the following steps that S1, a soybean meal raw material is screened, a first particle material and a powdery material are obtained, and the first particle material is extracted to prepare the soybean protein; s2, the powdery material is metered and then subjected to thermal refining; s3, granulating the conditioned powdery material to obtain a second granular material; and S4, extracting the second particle material to prepare the soybean protein. In the process, the raw materials are screened, the powdery materials are separated out, then the powdery materials are subjected to tempering and granulation treatment, the powdery materials are prepared into the particle materials, then the particle materials can be extracted together with the original particle materials in the raw materials, the utilization rate of the raw materials is greatly increased, the yield is increased, and the enterprise income is increased.

Description

Technical Field

[0001] The present invention relates to the field of food processing, and particularly to a process and device for preparing soy protein by granulating soybean meal fine powder. Background Art

[0002] In traditional soy protein production processes, if the raw materials contain too much powdered material (fine powder), in subsequent leaching sections, problems such as reduced leaching permeability, clogging of the leaching grid plate, increased fine powder content in the evaporation system mixed liquid, and clogging of evaporation tubes will occur. At the same time, materials with a high fine powder content usually need to reduce the material-liquid ratio to ensure that the mixed liquid in the extraction section does not flow back to other sections. A low material-liquid ratio often leads to incomplete extraction of alcohol-soluble substances such as sugars in soybean meal, resulting in a low protein content in the product. It is necessary to reduce the product moisture to meet the protein content requirements, increasing the steam consumption of the system.

[0003] To solve the above problems, traditional processes use a grading sieve to screen out the fine powder, and the sieve holes are generally between 50 and 80 meshes. To improve the utilization rate of raw materials, the sieve holes are not selected too large, otherwise, available soybean meal with a smaller particle size will be screened out, causing waste of raw materials.

[0004] The fine powder content in soybean meal is generally about 1 - 3%. The fine powder screened out after the soybean meal passes through the grading sieve cannot be effectively utilized. Generally, it is mixed back into the soybean meal and sold as primary feed or sold separately at a low price, resulting in waste of raw materials, reduced production line efficiency, reduced enterprise revenue, and at the same time, a large amount of fine powder will increase the enterprise's inventory pressure. Summary of the Invention

[0005] In view of the problem that the fine powder in soybean meal cannot be effectively utilized during the current production of soy protein, the present invention provides a process and device for preparing soy protein by granulating soybean meal fine powder.

[0006] To solve the above problems, the technical solution adopted by the present invention is a process for preparing soy protein by granulating soybean meal fine powder, which includes the following steps: S1. Screen the soybean meal raw materials to obtain the first granular material and powdered material, and extract soy protein from the first granular material. S2. Meter the powdered material and then perform conditioning treatment. S3. Granulate the conditioned powdered material to obtain the second granular material. S4. Extract soy protein from the second granular material.

[0007] In this process, by screening the raw materials, the powdery materials are separated, and then the powdery materials are conditioned and granulated to form granular materials, which can then be extracted together with the original granular materials in the raw materials, greatly improving the utilization rate of the raw materials. At the same time, problems such as grid plate blockage and evaporation tube blockage caused by a large content of powdery materials are avoided. Also, in the subsequent extraction section, there is no need to specifically adjust the processing parameter settings for the content of powdery materials, improving the yield and the enterprise's revenue.

[0008] As a preferred implementation of the process for preparing soy protein by granulating soybean meal fine powder, in step S2, when conditioning the powdery materials, the feeding flow rate is 2.5 - 3 tons per hour. By controlling the feeding flow rate, the conditioning process becomes more stable and efficient, ensuring that the powdery materials are fully processed in the conditioner and providing good material conditions for subsequent granulation, which helps improve the quality and yield of granulation.

[0009] As a preferred implementation of the process for preparing soy protein by granulating soybean meal fine powder, in step S2, hot water conditioning is used for the conditioning treatment. The hot water temperature is 30 - 50 °C, and the hot water flow rate is 0.1 - 0.2 m³ / h. The hot water flow rate is in interlock control with the feeding flow rate of the powdery materials. Precise control of the hot water temperature and flow rate and interlock control with the feeding flow rate can ensure that the moisture content of the powdery materials is uniform and stable during the conditioning process, which is beneficial to the forming and strength of the granules during subsequent granulation, improving the product quality stability and reducing product quality problems caused by improper moisture control.

[0010] As a preferred implementation of the process for preparing soy protein by granulating soybean meal fine powder, in step S2, steam conditioning is used for the conditioning treatment. The steam pressure is 0.55 - 0.65 MPa, and the steam pressure is in interlock control with the feeding flow rate of the powdery materials. By precisely controlling the steam pressure and interlocking it with the feeding flow rate, the powdery materials can be conditioned quickly and evenly, improving the conditioning efficiency. At the same time, it can effectively kill some microorganisms in the materials, enhancing the safety and shelf life of the product, and also improving the physical properties of the materials, facilitating subsequent granulation operations.

[0011] As a preferred implementation of the process for preparing soy protein by granulating soybean meal fine powder, in step S1, magnetic separation is carried out on the first granular materials to remove magnetic impurities; in step S4, magnetic separation is carried out on the second granular materials to remove magnetic impurities. Removing magnetic impurities by magnetic separation can effectively ensure the purity of the product, avoid wear on subsequent extraction equipment caused by magnetic impurities, extend the service life of the equipment, and improve the product quality at the same time.

[0012] As a preferred implementation of the process for preparing soy protein by granulating soybean meal fines, in step S3, the particle size of the second particulate material is 2 - 4 mm. The particulate material has better mass transfer efficiency during the extraction process, enabling the extractant to come into full contact with the material, increasing the extraction rate of soy protein, and the particles of this particle size are convenient for subsequent transportation, storage, and processing.

[0013] On the other hand, the present invention also provides a device for preparing soy protein by granulating soybean meal fines, including a sorting subsystem. The sorting subsystem has a whole - material outlet and a powder outlet. The whole - material outlet is connected to the extraction subsystem; the powder outlet is connected to a granulation subsystem. The granulation subsystem includes a powder storage bin, a metering feeder, a conditioner, and a granulator connected in sequence. The powder outlet is connected to the inlet of the powder storage bin, and the outlet of the granulator is connected to the extraction subsystem. In this system, a sorting subsystem and a granulation subsystem are added between the feeding and extraction subsystems. In the sorting subsystem, qualified particulate materials and powdery materials are separated, and then the powdery materials are conditioned and granulated to turn them into particulate materials, which are then subjected to subsequent leaching and extraction steps in the extraction subsystem together with the original particulate materials. Thus, the utilization rate of the materials is greatly improved, and the productivity of the production line is increased.

[0014] As a preferred implementation of the device for preparing soy protein by granulating soybean meal fines, the sorting subsystem includes a grading screen. The grading screen has a first outlet and a second outlet. The first outlet is connected to a whole - material temporary storage tank. The outlet of the whole - material temporary storage tank is connected to the extraction subsystem, and a whole - material weighing scale is provided on the connecting pipeline between the whole - material temporary storage tank and the extraction subsystem; the second outlet is connected to a powder temporary storage tank. The outlet of the powder temporary storage tank is connected to the powder storage bin of the granulation subsystem, and a powder weighing scale is also provided on the connecting pipeline between the powder temporary storage tank and the powder storage bin. The whole - material and the powder are stored temporarily and weighing scales are set, which is convenient for accurately controlling the amount of materials entering the subsequent subsystems, ensuring the stability and continuity of the production process, and improving the flexibility and adaptability of production.

[0015] As a preferred implementation of the device for preparing soy protein by granulating soybean meal fines, a cooling subsystem is also provided between the granulation subsystem and the extraction subsystem. The cooling subsystem includes a cooler and a cyclone dust collector. The outlet of the granulator is connected to the inlet of the cooler, the outlet of the cooler is connected to the extraction subsystem, the air inlet of the cyclone dust collector communicates with the inner cavity of the cooler, and the cyclone dust collector has an air outlet and a dust outlet. The air outlet is connected to an exhaust fan, and the dust outlet is connected to the extraction subsystem. The cooling subsystem can quickly cool the granulated materials, preventing the materials from affecting the extraction effect and product quality due to excessive temperature. Using the cyclone dust collector and the exhaust fan as the cold source of the cooling subsystem can timely discharge the moisture and ensure the dryness of the production environment.

[0016] As a preferred implementation of the device for preparing soy protein by granulating soybean meal fine powder, a powder buffer tank and a granulation buffer tank are further provided between the powder storage bin and the metering feeder. The powder storage bin is connected to the powder buffer tank through a metering auger, the outlet of the powder buffer tank is connected to the metering feeder, the outlet of the metering feeder is connected to the granulation buffer tank through a granulation weighing scale, and the granulation buffer tank is connected to the conditioner. The setting of the powder buffer tank and the granulation buffer tank can buffer the fluctuation of the material flow rate, ensure the stable operation of the metering feeder and the conditioner, reduce the production faults caused by unstable material supply, improve the production efficiency and the stability of product quality. At the same time, the granulation weighing scale can accurately control the amount of material entering the conditioner, further ensuring the accuracy of the feeding in each step during the morphological change of the material.

[0017] It can be seen from the above technical solutions that the advantages of the present invention are as follows: In terms of technology, by screening the soybean meal raw materials, the powdery materials are separated and subjected to conditioning and granulation treatment, so that they can be extracted together with the original granular materials. This not only greatly improves the utilization rate of raw materials, avoids the blockage problems of the grid plate and the evaporation tube caused by excessive powdery materials, but also increases the porosity of the extraction materials, is conducive to the penetration of the extraction liquid, improves the extraction efficiency of the materials, reduces the solvent spraying amount, and improves the yield and the enterprise income. Among them, the precise control of the feeding flow rate makes the conditioning process more stable and efficient, provides a good material basis for granulation, improves the granulation quality and the finished product rate; when conditioning with hot water, accurately controlling the hot water temperature, flow rate and interlocking with the feeding flow rate ensures the uniform and stable moisture content of the powdery materials during the conditioning process, is conducive to particle forming and strength, and improves the stability of product quality; when conditioning with steam, by accurately controlling the steam pressure and interlocking with the feeding flow rate, rapid and uniform conditioning can be achieved, and at the same time, some microorganisms can be killed, the anti-nutritional factors in the soybean meal powder can be removed, the product safety and shelf life can be improved, the physical properties of the materials can be improved, and subsequent granulation is facilitated; magnetic separation removes magnetic impurities, which not only ensures the product purity, but also avoids equipment wear and extends the service life of the equipment; controlling the particle size of the second granular material to be 2 - 4mm improves the extraction mass transfer efficiency and facilitates the subsequent treatment of the materials. In terms of the system, adding a sorting subsystem and a granulation subsystem improves the material utilization rate and the production line yield; in the sorting subsystem, a whole material and a powder temporary storage tank and a weighing scale are set up, which is convenient for accurately controlling the amount of materials, ensuring stable and continuous production, and enhancing the production flexibility and adaptability; the cooling subsystem can quickly cool the granulated materials, prevent them from affecting the extraction effect and product quality due to too high temperature, and at the same time discharge the moisture in time, reducing the water content of the granulated finished products; setting a powder buffer tank, a granulation buffer tank and a granulation weighing scale between the powder storage bin and the metering feeder can buffer the fluctuation of the material flow rate, ensure the stable operation of the equipment, reduce production faults, improve the production efficiency and the stability of product quality, and accurately control the feeding amount.

[0018] This solution successfully solves the problem that fine powder in soybean meal cannot be extracted, and the utilization rate of soybean meal is increased by 1-3%. The full material extraction of raw material soybean meal is realized, and there is no output of fine powder by-products. After the granulated material is mixed with soybean meal, the porosity of the leaching material is increased, the contact area between the alcohol solution and the material is increased, the extraction efficiency is improved, which is beneficial to the extraction of alcohol-soluble substances such as sugars, the protein content of the product is increased, and the protein product yield is improved. Description of the Drawings

[0019] In order to more clearly illustrate the technical solution of the present invention, the drawings required in the description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 It is a schematic structural diagram of the second embodiment of the present invention.

[0021] Main Reference Numerals Description 1. Grading screen, 2. Whole material temporary storage tank, 3. Whole material weighing scale, 4. Magnetic separator, 5. Powder temporary storage tank, 6. Powder weighing scale, 7. Powder elevator, 8. First scraper conveyor, 9. Powder storage bin, 10. Quantitative auger, 11. Second scraper conveyor, 12. Powder buffer tank, 13. Quantitative feeder, 14. Granulation weighing scale, 15. Granulation buffer tank, 16. Granulation conveying auger, 17. Conditioner, 18. Granulator, 19. Cooler, 20. Cyclone dust collector, 21. Moisture exhaust fan, 22. Extraction subsystem, 23. Steam supply device, 24. Hot water supply device. Detailed Embodiments

[0022] In order to make the objectives, features, and advantages of the present invention more obvious and understandable, the technical solutions in the present invention will be clearly and completely described below in conjunction with the drawings in the specific embodiments of the present invention. Obviously, the embodiments described below are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments in this patent, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this patent.

[0023] Embodiment 1 Soybean meal is a by-product obtained after extracting soybean oil from soybeans. It contains about 45% protein and is a high-quality source of plant protein. After soybean oil is extracted, large soybean cakes are crushed to obtain soybean meal. Normal soybean meal is in the form of irregular fragments or granules. During the crushing process, if the crushing force is too large or the crushing time is too long, the soybeans will be over-crushed and the soybean meal will become powdery. At the same time, different soybean varieties have differences in physical properties such as particle size, shape, and hardness. Some soybean varieties have smaller particles and softer textures, making them more likely to be crushed into fine powder during processing. In addition, during storage and transportation, due to factors such as jolting and loading and unloading, granular soybean meal will also produce fine powder.

[0024] In the leaching section of the process of producing soy protein from soybean meal, too much fine powder will fill the gaps between the material particles, reducing the porosity of the material. This causes the penetration path of the solvent in the material layer to become tortuous and complex, making it difficult for the solvent to smoothly penetrate to all parts of the material pile, thus affecting the leaching efficiency. The diffusion process of alcohol-soluble substances such as sugars from the inside of the material to the solvent will also be interfered by the fine powder. Too much fine powder will increase the resistance to the diffusion of alcohol-soluble substances such as sugars. This means that within the same leaching time, the amount of alcohol-soluble substances such as sugars that can be extracted by the solvent will decrease, reducing the leaching effect. For equipment, too much fine powder is likely to adhere to the equipment surface or aggregate with each other, and may block equipment components such as the sieve mesh of the leaching tank, pipelines, and filters in the solvent recovery system. When spray leaching is used, the fine powder may accumulate at the spray head, causing the spray head to be blocked and the solvent to be unable to be evenly sprayed onto the material.

[0025] To solve the influence of the above-mentioned fine powder, this embodiment provides a process for granulating soybean meal fine powder to prepare soy protein, including the following steps: S1. First, screen the soybean meal raw material to obtain the first granular material and powdery material (i.e., the above-mentioned fine powder). The first granular material is the material in the soybean meal raw material that meets the requirements of the normal leaching process. The first granular material is subjected to magnetic separation to remove magnetic impurities and then directly put into the subsequent extraction section (including leaching and extraction steps) to produce soy protein; S2. For the powdery material in S1, after metering, it is subjected to conditioning treatment. Specifically, the conditioning treatment can use hot water conditioning or steam conditioning: When hot water conditioning is selected, the hot water temperature is 30 - 50 °C, and the flow rate of the hot water is controlled in a chain with the feeding flow rate of the powdery material. By metering the powdery material, the feeding flow rate is controlled to be 2.5 - 3 tons per hour. At this feeding flow rate, the hot water flow rate is set to 0.1 - 0.2 m³ / h. When the feeding flow rate increases, the hot water flow rate also increases; When selecting steam conditioning, the steam pressure is 0.55 - 0.65 MPa, the feeding flow rate is 2.5 - 3 tons per hour, and the steam pressure is interlocked with the feeding flow rate of the powdery material. When the feeding flow rate increases, the steam pressure also increases; Compared with hot water conditioning, the output of steam conditioning is about 30% higher than that of hot water conditioning. However, the porosity of the granulated material after steam conditioning is low and the material is dense. The porosity of the granulated material after hot water conditioning is higher, and the conditioning process can be selected according to needs; S3. The conditioned powdery material is granulated to obtain the second granular material. Granulation preferably adopts the granulation method of high-pressure compression and expansion to make the obtained granular material more porous. The particle size of the second granular material is preferably 2 - 4 mm; S4. The second granular material is cooled, and then magnetically separated to remove magnetic impurities, and then put into the subsequent extraction section together with the first granular material for extracting soybean protein.

[0026] Based on the original process, this process conditions and granulates the screened powdery material to make it into granular material, which is more suitable for the subsequent leaching and extraction steps, eliminates the influence caused by excessive fine powder, and at the same time makes full use of the powdery material, improving the raw material utilization rate and output rate.

[0027] Example Two This example further provides a device for granulating soybean meal fines to prepare soybean protein, which can implement the process of granulating soybean meal fines to prepare soybean protein provided in Example One. This system includes a sorting subsystem, a granulating subsystem, a cooling subsystem, and an extraction subsystem. The sorting subsystem has a whole material outlet and a powder material outlet. The whole material outlet is connected to the extraction subsystem; the powder material outlet is connected to the granulating subsystem. The outlet of the granulating subsystem is connected to the cooling subsystem, and the outlet of the cooling subsystem is connected to the extraction subsystem, specifically as Figure 1 shown: The sorting subsystem includes a grading screen 1. The grading screen 1 can adopt a vibrating screen (an existing device, and its specific structure will not be described in detail here). The screen mesh of the grading screen 1 is preferably 50 - 80 meshes. The grading screen screens the material into powdery material and the first granular material. In this regard, the grading screen has a first outlet and a second outlet. The first outlet corresponds to the first granular material, and the first outlet is connected to a whole material temporary storage tank 2. The second outlet corresponds to the powdery material, and the second outlet is connected to a powder material temporary storage tank 5. A powder material weighing scale 6 is provided at the outlet of the powder material temporary storage tank 5. The powdery material is collected and temporarily stored in the powder material temporary storage tank 5 and enters the granulating subsystem after being weighed.

[0028] The particle making system includes a powder storage bin 9, which is a large tank structure for storing a large amount of powdered materials. According to the layout of the production system, the outlet of the powder weighing scale 6 is connected to the top inlet of the powder storage bin 9 through a powder elevator 7 and a first scraper conveyor 8. A metering auger 10 is provided at the bottom outlet of the powder storage bin 9, and the metering auger 10 conveys the powdered material to the second scraper conveyor 11. The specification of the metering auger can be increased to ensure that the material is not further pulverized and the fineness of the fine powder is reduced. The metering auger 10 is controlled by frequency conversion, and the frequency is 10 - 25 Hz; the second scraper conveyor 11 feeds the powdered material into the powder buffer tank 12, and the powder buffer tank 12 is connected to the granulation weighing scale 14 through a metering feeder 13. The granulation weighing scale 14 is further connected to a granulation buffer tank 15. The granulation weighing scale 14 cooperates with the metering feeder 13 to accurately control the input of the powdered material in the granulation buffer tank 15. The metering feeder 13 is controlled by frequency conversion, and the frequency is controlled at about 25 Hz. The flow rate of the granulation weighing scale 14 is stable at 2.5 - 3 tons per hour. The outlet of the granulation buffer tank 15 is connected to a granulation conveying auger 16, and the granulation conveying auger 16 feeds the powdered material into the conditioner 17. Adapted to the two conditioning methods given in the first embodiment, the particle making system is also equipped with a steam supply device 23 (such as a steam header) and a hot water supply device 24 (such as a hot water pump). The steam supply device 23 and the hot water supply device 24 are respectively connected to the granulation buffer tank 15 and / or the granulation conveying auger 16 and / or the conditioner 17 through pipelines. The discharge end of the granulation conveying auger is provided with a 200 mm long sealed end, and hot water or steam is introduced into the middle section of the sealed auger to ensure full mixing of the powdered material with hot water or steam and infiltration of the fine powder. The outlet of the conditioner 17 is connected to a granulator 18. The granulator 18 adopts a flat die granulation method with high-pressure compression and expansion and an orifice plate to make the conditioned powdered material into second granular materials, and the current of the granulator is controlled at 80 A.

[0029] The discharge port of the granulator 18 is connected to the cooling subsystem. The cooling subsystem includes a cooler 19, which is a scraper type through-flow cooler, having the functions of both material transportation and temperature reduction and cooling. The discharge temperature of the granulator is about 60 °C and is reduced to 40 °C in the cooler. The moisture discharge pipe of the cooler 19 is connected to a moisture discharge fan 21. Natural air enters from the lower cavity of the cooler 19, penetrates the material layer to carry away the flash steam in the material, and passes through the moisture discharge pipe at the top of the cooler and is taken away by the moisture discharge fan 21. Since the material pressure at the outlet of the granulator drops rapidly, a small amount of powder will be carried while the moisture flashes and cools down. Therefore, a cyclone dust collector 20 is provided between the cooler 19 and the moisture discharge fan 21. The moisture discharge pipe of the cooler 19 is connected to the air inlet of the cyclone dust collector 20, and the moisture discharge fan 21 is connected to the air outlet of the cyclone dust collector 20. The trace dust collected at the dust outlet of the cyclone dust collector can be mixed into the second granular material after temperature reduction. Since the amount of dust is extremely small, it will not affect the subsequent leaching and extraction; or the outlet of the cyclone dust collector can be connected back to the powder storage bin and mixed with the powdered material screened by the grading screen to completely eliminate the dust in the discharge of the granulating subsystem. The air after dust removal can be directly discharged into the atmosphere.

[0030] The extraction subsystem can adopt existing leaching and extraction equipment, and its specific structure will not be elaborated here. The feeding end of the extraction subsystem is provided with a collecting pipeline for collecting the first granular material from the sorting subsystem and the second granular material from the cooling system. A magnetic separator 4 is provided on this collecting pipeline to remove ferromagnetic impurities in the first and second materials.

[0031] As can be seen from the above embodiments, the beneficial effects of the present invention are as follows. In terms of technology, by screening the soybean meal raw materials, the powdery materials are separated and subjected to conditioning and granulation treatment, so that they can be extracted together with the original granular materials. This not only greatly improves the utilization rate of raw materials, avoids the problems of grid plate and evaporation tube blockage caused by excessive powdery materials, but also increases the porosity of the extracted materials, which is conducive to the penetration of the extraction liquid, improves the extraction efficiency of the materials, reduces the solvent spraying amount, and thus improves the yield and the enterprise's income. Among them, the precise control of the feeding flow rate makes the conditioning process more stable and efficient, provides a good material basis for granulation, and improves the granulation quality and the finished product rate; when conditioning with hot water, precisely controlling the hot water temperature, flow rate and interlocking with the feeding flow rate ensures that the moisture of the powdery materials is uniform and stable during the conditioning process, which is conducive to particle forming and strength, and improves the product quality stability; steam conditioning realizes rapid and uniform conditioning by precisely controlling the steam pressure and interlocking with the feeding flow rate, can also kill some microorganisms, remove the anti-nutritional factors in the soybean meal powder, improve the product safety and shelf life, and improve the physical properties of the materials, which is convenient for subsequent granulation; magnetic separation removes magnetic impurities, which not only ensures the product purity, but also avoids equipment wear and extends the service life of the equipment; controlling the particle size of the second granular material to be 2 - 4mm improves the extraction mass transfer efficiency and is convenient for subsequent material processing. In terms of the system, adding a sorting subsystem and a granulation subsystem improves the utilization rate of materials and the production line yield; in the sorting subsystem, a whole material and a powdery material temporary storage tank and a weighing scale are set up, which is convenient for precisely controlling the material quantity, ensuring stable and continuous production, and enhancing the production flexibility and adaptability; the cooling subsystem can quickly cool the granulated materials, prevent them from affecting the extraction effect and product quality due to too high temperature, and at the same time discharge the moisture in time to reduce the water content of the granulated finished products; a powdery material buffer tank, a granulation buffer tank and a granulation weighing scale are set between the powdery material storage bin and the quantitative feeder, which can buffer the material flow rate fluctuation, ensure the stable operation of the equipment, reduce production failures, improve the production efficiency and the product quality stability, and precisely control the feeding quantity. This solution successfully solves the problem that the fine powder in soybean meal cannot be extracted, and the utilization rate of soybean meal is increased by 1 - 3%. The whole material extraction of the raw material soybean meal is realized, and there is no output of fine powder by-products. After the granulated materials are mixed with soybean meal, the porosity of the leaching materials is increased, the contact area between the alcohol solution and the materials is increased, the extraction efficiency is improved, which is conducive to the extraction of alcohol-soluble substances such as sugars, the protein content of the product is increased, and the protein product yield is improved.

[0032] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A process for preparing soybean protein by granulating soybean meal fine powder, characterized in that: The following steps are involved: S1. The soybean meal raw material is screened to obtain a first granular material and a powdered material, and the first granular material is extracted to produce soy protein; S2. Tempering the powdered material after metering; S3. The powdered material after conditioning is granulated to obtain a second granular material; S4. Extracting the second granular material to obtain soybean protein.

2. The process for preparing soybean protein by granulating soybean meal fine powder according to claim 1, characterized in that: In step S2, when the powdery material is conditioned, the feed flow rate is 2.5-3 tons / hour.

3. The process for preparing soybean protein by granulating soybean meal fine powder according to claim 2, characterized in that: In step S2, the tempering treatment adopts hot water tempering, the hot water temperature is 30-50°C, the hot water flow rate is 0.2-0.3m³ / h, and the hot water flow rate is linked to the feed flow rate of the powdered material.

4. The process for preparing soybean protein by granulating soybean meal fine powder according to claim 2, characterized in that: In step S2, the tempering treatment adopts steam tempering, the steam pressure is 0.55-0.65MPa, and the steam pressure is linked to the feed flow rate of the powdered material.

5. The process for preparing soybean protein by granulating soybean meal fine powder according to claim 1, characterized in that: In step S1, magnetic impurities are removed from the first particulate material by magnetic separation; in step S4, magnetic impurities are removed from the second particulate material by magnetic separation.

6. The process for preparing soybean protein by granulating soybean meal fine powder according to claim 1, characterized in that: In step S3, the particle size of the second particulate material is 2-4 mm.

7. A device for preparing soybean protein by granulating soybean meal fine powder, characterized in that: The process for preparing soy protein by granulating soybean meal fine powder as described in any one of claims 1 to 6 comprises a sorting subsystem, the sorting subsystem having a whole material outlet and a powder material outlet, the whole material outlet being connected to an extraction subsystem; the powder material outlet being connected to a granulation system, the granulation system comprising a powder material storage bin (9), a quantitative feeder (13), a conditioner (17) and a granulator (18) connected in sequence, the powder material outlet being connected to an inlet of the powder material storage bin (9), and the outlet of the granulator (18) being connected to the extraction subsystem.

8. The device for preparing soybean protein by granulating soybean meal fine powder according to claim 7, characterized in that: The sorting subsystem comprises a grading screen (1), the grading screen (1) having a first outlet and a second outlet, the first outlet being connected to a bulk material temporary storage tank (2), the outlet of the bulk material temporary storage tank (2) being connected to an extraction subsystem, and a bulk material weighing scale (3) being provided on a connecting pipe between the bulk material temporary storage tank (2) and the extraction subsystem; the second outlet being connected to a powder material temporary storage tank (5), the outlet of the powder material temporary storage tank (5) being connected to a powder material storage bin (9) of the granulation system, and a powder material weighing scale (6) being provided on a connecting pipe between the powder material temporary storage tank (5) and the powder material storage bin (9).

9. The device for preparing soybean protein by granulating soybean meal fine powder according to claim 7, characterized in that: A cooling subsystem is also provided between the granulation system and the extraction subsystem, the cooling subsystem comprising a cooler (19) and a cyclone dust collector (20), the outlet of the granulator (18) is connected to the inlet of the cooler (19), the outlet of the cooler (19) is connected to the extraction subsystem, the air inlet of the cyclone dust collector (20) is connected to the inner cavity of the cooler (19), the cyclone dust collector (20) has an air outlet and a dust outlet, the air outlet is connected to a moisture exhaust fan (21), and the dust outlet is connected to the extraction subsystem.

10. The device for preparing soybean protein by granulating soybean meal fine powder according to claim 7, characterized in that: A powder buffer tank (12) and a granulation buffer tank (15) are further provided between the powder storage bin (9) and the quantitative feeder (13); the powder storage bin (9) is connected to the powder buffer tank (12) via a quantitative auger (10); the outlet of the powder buffer tank (12) is connected to the quantitative feeder (13); the outlet of the quantitative feeder (13) is connected to the granulation buffer tank (15) via a granulation metering scale (14); and the granulation buffer tank (15) is connected to the conditioner (17).

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