Inoculation device for natto production and production method

Abstract

The invention relates to the technical field of food processing machinery, discloses an inoculation device for natto production and a production method, and aims to solve the problems of non-uniform inoculation, bacterial liquid waste, incapability of continuous production and the like in the prior art. The device comprises a tank body assembly, a material turning and path switching mechanism, a jacking type gate mechanism, an electrostatic spraying system and an online quality monitoring system. The tank body is divided into a mixing cavity and a backflow cavity by an arc-shaped partition plate. The core is that the material turning and guiding piece rotating in one direction is provided with a first guiding face and a second guiding face which have different functions, and the material turning and guiding piece and the liftable lifting table work cooperatively. In the working process, the lifting table is at a high position, materials are lifted up by the first flow guide face and roll down, circular flow is formed through the backflow cavity, and in the process, the electrostatic spraying system accurately adsorbs liquid with bacteria to beans; the on-line monitoring system judges the uniformity in real time, the lifting platform descends to a low position after the uniformity reaches the standard, and the material turning and guiding piece guides the material to the material discharging and guiding plate to complete automatic material discharging.

Description

Technical Field

[0001] This invention relates to the field of food processing machinery technology, and in particular to an inoculation device and production method for natto production. Background Technology

[0002] Natto, a traditional fermented soybean product, is widely popular due to its unique taste and rich nutritional value. The inoculation process, where natto bacteria are evenly inoculated onto steamed soybeans, is a crucial step in determining the product's quality and stability.

[0003] Currently, the most common inoculation methods used in the industry include manual inoculation and simple mechanical mixing inoculation. Manual inoculation relies on the operator's experience, involving splashing the bacterial solution onto the soybeans and stirring. This method suffers from numerous drawbacks, including imprecise control of the inoculation amount, poor uniformity, low production efficiency, and susceptibility to human contamination. While mechanical mixing inoculation reduces labor intensity to some extent, it often uses open-top mixing tanks. The mixing blades can easily crush and damage the soybeans during the material movement, and it is difficult to avoid creating dead zones around the mixing mechanism, resulting in uneven distribution of the bacterial solution and large fluctuations in batch product quality. In addition, both methods suffer from significant waste of the bacterial solution, with large amounts of it failing to be effectively utilized due to splashing or adhering to the inner walls of the equipment.

[0004] To address the uniformity issue, some improved technologies have proposed atomizing the bacterial solution before spraying. However, simple spraying still struggles to ensure uniform coverage of each bean, especially for beans piled at the bottom. Furthermore, existing mixing equipment generally suffers from incomplete discharge and residue after mixing, leading to material waste and potential batch-to-batch cross-contamination, failing to meet the demands of modern food industry for efficient, clean, and continuous production.

[0005] Therefore, there is an urgent need in this field for a novel natto inoculation device and method that can achieve precise and uniform inoculation of bacterial culture, while also being automated, airtight, and adaptable to continuous production of multiple batches. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing an inoculation device and production method for natto production.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: An inoculation device for natto production, comprising: The tank assembly has a feed inlet at the top and a discharge valve at the end. The interior of the tank is divided into a mixing chamber and a reflux chamber by an arc-shaped partition. The reflux chamber has a feed window on its side wall that communicates with the mixing chamber. The bottom of the reflux chamber is connected to a collection bin located at the bottom of the tank. The material turning and path switching mechanism includes a drive shaft rotatably mounted at the center of the tank assembly via a bearing seat, which is driven to rotate by a drive motor fixedly mounted at the end of the tank assembly; a material turning guide is fixedly mounted on the drive shaft, and the two sides of the material turning guide are a first guide surface and a second guide surface, respectively; when the two side edges of the material turning guide rotate with the drive shaft, they can periodically sweep across the upper space of the collection bin; A lifting gate mechanism includes a lifting platform that can be slidably installed in a collection bin, and a linear actuator fixedly installed at the bottom of the collection bin. The output end of the linear actuator is connected to the lifting platform for driving the lifting platform to rise and fall. When the lifting platform rises to the high position, the side of the lifting platform blocks the connection between the return chamber and the collection bin, so that a hopper space for temporary storage of materials is formed in the collection bin. When the lifting platform falls to the low position, the connection between the return chamber and the collection bin is fully opened. An electrostatic spraying system includes at least one electrostatic atomizing nozzle fixedly installed on the inner wall of the tank and located above the mixing chamber. The electrostatic atomizing nozzle is connected to an external bacterial liquid supply unit and a high-voltage electrostatic generator via a pipeline. The online quality monitoring system includes a near-infrared spectral sensor fixedly mounted on the wall of the reflux chamber. The detection window of the near-infrared spectral sensor faces the internal channel of the reflux chamber and is used to detect the composition information of the material flowing through it in real time.

[0008] Preferably, the material turning guide is a plate-shaped component, the first guiding surface of which and the drive shaft are both made of conductive material and are electrically connected, and the drive shaft is electrically grounded through a bearing seat.

[0009] A flexible baffle is fixedly installed on the first guide surface of the material turning guide, and the length direction of the flexible baffle is consistent with the direction of the axis of the drive shaft.

[0010] Preferably, the second guide surface of the material turning guide is fixedly installed with a discharge guide plate, and the inner wall of the discharge guide plate forms an inclined working groove. The lower end of the inclined working groove points to the discharge valve. When the device is in the discharge mode and the material turning guide rotates, its second guide surface can guide the material into the inclined working groove of the discharge guide plate.

[0011] Preferably, the inner wall of the reflux cavity is provided with a detection cavity, which is separated from the reflux cavity by a glass plate, and the detection end of the near-infrared spectral sensor extends into the detection cavity.

[0012] Preferably, an electric heating tube is embedded in the tank wall of the tank assembly, and a temperature sensor extending into the inner cavity of the tank is provided on the top of the tank assembly.

[0013] Preferably, the online quality monitoring system further includes a control unit electrically connected to the near-infrared spectral sensor, the control unit outputting control signals to the linear driver and drive motor based on the real-time monitoring data of the near-infrared spectral sensor.

[0014] A method for producing an inoculation device for natto production includes the following steps: S1. Feeding and initialization: Soybeans that have been cooked and cooled to the inoculation temperature are fed into the tank through the feed inlet. The lifting platform of the top-lifting gate mechanism is raised to the high position, and the drive motor is started to make the material turning guide rotate continuously in one direction. S2. Circulating mixing and electrostatic spraying: The material in the collection bin is scooped up and lifted by the first guide surface of the rotating material tilting guide; After being lifted to a certain height, the material rolls down along the first guide surface under the action of gravity and enters the return chamber through the feed window; The material is temporarily stored in layers in the reflux chamber and then slides down, eventually falling back into the collection bin to complete one cycle. During this process, the electrostatic spray system is activated. The bacterial liquid is atomized by the electrostatic atomizing nozzle and charged before being sprayed onto the material falling in the mixing chamber. S3. Online monitoring and pattern determination: The near-infrared spectral sensor of the online quality monitoring system monitors the amount of bacterial liquid adhering to the material in the reflux chamber in real time; The control unit continuously receives monitoring data. When it determines that the amount of bacterial liquid adhering to the substrate has reached a preset threshold and the data tends to stabilize, it generates a mode switching command. S4. Sequential Material Discharge: Based on the determination result of S3, the control unit automatically executes the material discharge procedure, which includes two stages: Phase 1 (Mode Switching): The control unit outputs a command to drive the lifting platform to descend to the low position, opening the channel between the return chamber and the collection bin.

[0015] Phase Two (Step-by-Step Discharge): The control unit instructs the lifting platform to rise in steps and intermittently, while the material-turning guide continues to rotate. With each rise of the lifting platform, the material accumulated at the bottom of the collection bin is lifted in batches and scooped up by the second guide surface of the material-turning guide, guided to the discharge guide plate, and finally discharged in an orderly manner through the discharge valve until the material is emptied.

[0016] In step S2, the material forms a circulation channel between the collection bin, the mixing chamber and the return chamber, and the material is temporarily stored in the return chamber in a "last in, last out, layered" manner, so that all materials undergo the same number of cyclic sprays.

[0017] The present invention has the following beneficial effects: 1. The inoculation device for natto production proposed in this invention combines electrostatic spraying technology. Charged bacterial droplets are directionally and precisely adsorbed onto the surface of the natto grains under the action of an electric field, greatly reducing the waste caused by the bacterial solution drifting, spraying, or adhering to the inner wall of the equipment. The first guide surface of its material turning guide has the function of guiding the material to roll along its surface. This rolling motion allows each natto grain to be fully and multi-angledly exposed in the electrostatic spraying area. Compared with the "pushing" and "crushing" of the material by traditional stirring blades, it greatly increases the effective contact area and contact opportunities between the natto grains and the bacterial droplets, laying the foundation for uniform adsorption from a physical mechanism and effectively avoiding the problem of uneven local inoculation.

[0018] 2. The inoculation device for natto production proposed in this invention divides the inner cavity of the tank into a mixing chamber and a reflux chamber through an arc-shaped baffle, which forcibly plans a clear movement path for the material. The material is lifted, dispersed and sprayed in the mixing chamber, and settles, is temporarily stored and recirculated in the reflux chamber. This structural design enables the material to form a stable and controllable circulating flow in the tank, rather than a disordered turbulent flow. The material is temporarily stored in the reflux chamber in a stratified manner of "first in first out" or "last in last out", which realizes homogenization in the time dimension and ensures that all materials undergo nearly the same processing process, thus solving the uniformity problem from both spatial and temporal dimensions.

[0019] 3. The natto production method proposed in this invention cleverly alters the material's trajectory by utilizing the simple variable of the lifting platform's height, combined with a unidirectional rotating material guide. When the lifting platform is at a high position, the material is scooped up and rolls back along the first guide surface into the circulation path; when the lifting platform is at a low position, the material is guided to the second guide surface and slides towards the discharge port. This mode switching is entirely achieved by the functional area of ​​the mechanical structure itself, without the need for complex forward and reverse rotation control or additional actuators. It features a simple structure, reliable operation, and low failure rate, fundamentally solving the problem of inconvenient material discharge in traditional mixing equipment. This facilitates continuous, multi-batch cyclic production, improving equipment utilization and overall production efficiency.

[0020] 4. The natto production method proposed in this invention highly integrates multiple functional units such as circulating mixing, electrostatic spraying, online monitoring, and mode switching into a compact tank assembly. This integrated structure reduces external conveying links and shortens the process flow, not only improving space utilization and production efficiency, but more importantly, greatly reducing the risk of equipment contamination caused by multiple connections, and meeting the stringent hygiene requirements of food processing equipment. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the three-dimensional structure of the inoculation device proposed in this invention. Figure 1 .

[0022] Figure 2 This is a schematic diagram of the three-dimensional structure of the inoculation device proposed in this invention. Figure 2 .

[0023] Figure 3 This is a schematic diagram of the cross-sectional structure of the inoculation device proposed in this invention.

[0024] Figure 4 This is a three-dimensional structural diagram of the material turning and guiding component proposed in this invention.

[0025] Figure 5 This is a three-dimensional structural diagram of the discharge guide plate proposed in this invention.

[0026] Figure 6 This is a schematic diagram showing the layered stacking of materials within the reflux chamber.

[0027] Figure 7 This is a schematic diagram of the process of material being lifted, dispersed, and sprayed in the mixing chamber.

[0028] Figure 8 This is a schematic diagram of the process by which materials are guided to the second guide surface and slide towards the discharge port.

[0029] In the picture: 100. Tank assembly; 101. Feed inlet; 102. Discharge valve; 103. Arc-shaped baffle; 104. Mixing chamber; 105. Reflux chamber; 106. Feed window; 107. Collection bin; 201. Drive shaft; 202. Drive motor; 203. Material tilting guide; 204. First guide surface; 205. Second guide surface; 206. Flexible baffle; 207. Discharge guide plate; 301. Lifting platform; 302. Linear actuator; 401. Electrostatic atomizing nozzle; 402. Glass plate; 501, Near-infrared spectroscopy sensor; 601, Temperature sensor. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] Example 1

[0033] Reference Figures 1-8 An inoculation device for natto production includes: a tank assembly 100, a material turning and path switching mechanism, a lifting gate mechanism, an electrostatic spraying system, and an online quality monitoring system, as detailed below: The tank assembly 100 has a feed inlet 101 at the top and a discharge valve 102 at the end. The interior of the tank is divided into a mixing chamber 104 and a reflux chamber 105 by an arc-shaped baffle 103. Figure 3 As shown; a feed window 106 communicating with the mixing chamber 104 is provided on the side wall of the reflux chamber 105. The bottom of the reflux chamber 105 is connected to a collection bin 107 located at the bottom of the tank. An electric heating tube is embedded in the tank wall of the tank assembly 100. A temperature sensor 601 extending into the inner cavity of the tank is provided on the top of the tank assembly 100. The temperature sensor 601 (PT100 type, accuracy ±0.5℃) is linked with the PID controller and the electric heating tube is used to heat it and maintain the temperature inside the tank at 50±2℃ to ensure the thermal stability of the inoculation process.

[0034] Material turning and path switching mechanism, see reference. Figure 3 , Figure 4 , Figure 5 It includes a drive shaft 201 rotatably mounted at the center of the tank assembly 100 via a bearing housing, and driven to rotate by a drive motor 202 fixedly mounted at the end of the tank. A material-turning guide 203 is fixedly mounted on the drive shaft 201, and the two sides of the material-turning guide 203 are a first guide surface 204 and a second guide surface 205, respectively. When the two side edges of the material-turning guide 203 rotate with the drive shaft 201, they can periodically sweep across the upper space of the collection bin 107. Preferably, the drive motor 202 is a geared motor. Figure 5 A gap is reserved between the material tipping guide 203 and the drive shaft 201 so that the material can fall through the gap; The material-turning guide component 203 is a plate-shaped component. Its first guide surface 204 and the drive shaft 201 are both made of conductive material and are electrically connected. The drive shaft 201 is electrically grounded through a bearing seat. A flexible baffle 206 is fixedly installed on the first guide surface 204 of the material-turning guide component 203. The length direction of the flexible baffle 206 is consistent with the axis of the drive shaft 201. Figure 7 As shown in Figure c, when the material guide 203 is tilted, the weight of the material (soybeans) presses down on the flexible baffle 206, causing the flexible baffle 206 to bend and play a certain blocking role, slowing down the rolling speed of the material, and allowing the material to slowly roll down along the first guide surface 204 and spread out fully. This not only avoids the damage to the soybeans caused by free fall, but also prolongs the residence time of the material in the electrostatic spray area, increasing the chance of bacterial liquid adsorption.

[0035] like Figure 5 As shown, a discharge guide plate 207 is fixedly installed on the second guide surface 205 of the material tilting guide 203. An inclined working groove is formed on the inner wall of the discharge guide plate 207, with the lower end of the inclined working groove pointing towards the discharge valve 102. When the device is in discharge mode and the material tilting guide 203 rotates, its second guide surface 205 can guide the material into the inclined working groove of the discharge guide plate 207. (Refer to...) Figure 8 As shown in Figure f, the material in the inclined working trough rolls into the discharge valve 102, and the discharge valve 102 is opened to discharge the material.

[0036] Lifting gate mechanism, such as Figure 3 As shown, it includes a lifting platform 301 that can be slidably disposed within the collection hopper 107, and a linear actuator 302 fixedly installed at the bottom of the collection hopper 107. The output end of the linear actuator 302 is connected to the lifting platform 301 for driving the lifting platform 301 to rise and fall. The curvature of the upper surface of the lifting platform 301 is consistent with the curvature of the inner wall of the mixing chamber 104. The linear actuator 302 can be an electric push rod or a hydraulic cylinder; Figure 8 As shown in Figure f, when the lifting platform 301 rises to the high position, the side of the lifting platform 301 blocks the connection between the return cavity 105 and the collection bin 107, thus forming a hopper space within the collection bin 107 for temporary material storage; as shown in Figure f. Figure 8 As shown in Figure e, when the lifting platform 301 descends to the low position, the connection between the return chamber 105 and the collection bin 107 is fully opened.

[0037] The electrostatic spraying system includes at least one electrostatic atomizing nozzle 401 fixedly installed on the inner wall of the tank and located above the mixing chamber 104. The electrostatic atomizing nozzle 401 is connected to an external bacterial liquid supply unit and a high-voltage electrostatic generator through a pipeline. The bacterial liquid mist sprayed by the electrostatic atomizing nozzle 401 carries a negative charge, forming charged droplets. Under the action of an electric field, the droplets are directionally adsorbed onto the grounded bean surface, avoiding scattering and waste, and improving adsorption efficiency.

[0038] The online quality monitoring system includes a near-infrared spectral sensor 501 fixedly installed on the wall of the reflux chamber 105. The inner wall of the reflux chamber 105 is provided with a detection chamber, which is separated from the reflux chamber 105 by a glass plate 402. The detection end of the near-infrared spectral sensor 501 extends into the detection chamber. The near-infrared spectral sensor 501 is a model NIRQuest512 with a wavelength range of 900-1700nm. The detection window of the near-infrared spectral sensor 501 faces the internal channel of the reflux chamber 105. The near-infrared spectral sensor 501 emits near-infrared light. The bacterial components in the material have characteristic absorption at specific wavelengths. By analyzing the intensity of the reflected spectrum, the amount of bacterial adhesion is calculated in real time.

[0039] In this embodiment, the online quality monitoring system also includes a control unit electrically connected to the near-infrared spectral sensor 501. The control unit (PLC, Siemens S7-1200) collects real-time monitoring data from the near-infrared spectral sensor 501 and calculates the coefficient of variation (CV value) of the bacterial suspension adhesion. When the CV value is <5% and remains so for 3 minutes, the uniformity is deemed to meet the standard. The control unit then outputs the following serialized instructions according to a preset program: (1) Mode switching instruction: First, the linear driver 302 is instructed to drive the lifting platform 301 to descend to the low position, completing the switch from "mixed mode" to "discharge mode"; (2) Discharge execution command: Subsequently, the linear driver 302 is instructed to drive the lifting platform 301 to perform step-by-step, intermittent lifting (that is, after each set height is raised, it pauses and continues to rise after the material is discharged), and at the same time, the drive motor 202 is instructed to adjust the speed to a speed more suitable for discharging. These two sequential instructions ensure a smooth and controllable discharge process, preventing blockage of the discharge port or material compression.

[0040] Working principle Vaccination process: such as Figure 7 As shown in Figure a, the linear drive 302 lifts the lifting platform 301, and the material in the collection bin 107 enters the lower side of the mixing chamber 104. like Figure 7 As shown in b, the drive motor 202 drives the material-turning guide 203 to rotate clockwise (15 rpm). The material in the mixing chamber 104 is picked up by the material-turning guide 203, lifted to the highest point, and then rolls down along the first guide surface 204 (as shown in b). Figure 7 c) At this point, the bacterial liquid mist sprayed from the electrostatic atomizing nozzle 401, under the action of the electric field, causes the droplets to be directionally adsorbed onto the grounded bean surface. Then, the material enters the reflux chamber 105 through the feed window 106; the material is temporarily stored in the reflux chamber 105 in a "last-in, last-out" manner (e.g., ...). Figure 6 ), forming a circulating flow; It should be noted that, as Figure 6 As shown, the material in the collection bin 107 blocks the downward flow of the material in the return chamber 105. When the material in the return chamber 105 increases, the lifting platform 301 is gradually lifted, gradually closing the connection between the return chamber 105 and the collection bin 107, so that the material in the return chamber 105 cannot be discharged immediately, and the material in the return chamber 105 is temporarily stored in layers. When the next cycle is needed, the linear drive 302 drives the lifting platform 301 to briefly descend to a low position, so that the temporarily stored material falls into the collection bin 107. Then the lifting platform 301 returns to a high position, and the material falling into the collection bin 107 can be picked up again by the material tilting guide 203 for a new round of spraying and inoculation, thereby realizing multiple cycles of all materials. Discharge process: When the online quality monitoring system detects that the bacterial liquid adhesion level meets the standard, the control unit instructs the lifting platform 301 to descend to the low position, such as... Figure 8 As shown in Figure d, the lifting platform 301 descends, and the material in the return chamber 105 enters the collection bin 107. Through the lifting of the lifting platform 301, the material tilting guide 203 continues to rotate clockwise, as... Figure 8 As shown in Figure e, the material in the mixing chamber 104 is scooped up by the material-turning guide 203, lifted to its highest point, and then rolls down along the second guide surface 205. Figure 8 As shown in f, the material is guided to the inclined working trough of the discharge guide plate 207, and the material slides into the discharge valve 102 for discharge. The whole process is carried out in a closed manner to avoid cross-contamination. It should be noted that, to ensure smooth discharge, prevent blockage of the discharge valve 102 due to excessive material, and reduce damage to the beans caused by compression, the control unit controls the linear actuator 302 to drive the lifting platform 301 in a step-by-step, intermittent manner. That is, the lifting platform 301 rises a short distance, discharges some material, pauses, and waits for the material guide 203 to clear the discharged material before continuing to rise a short distance. This cycle continues until all material in the collection bin 107 and the return chamber 105 is emptied.

[0041] The inoculation device for natto production proposed in this invention combines electrostatic spraying technology. Charged bacterial droplets are directionally and precisely adsorbed onto the surface of the natto grains under the action of an electric field, greatly reducing the waste caused by the bacterial solution drifting, spraying, or adhering to the inner wall of the equipment. The first guide surface 204 of the material turning guide component 203 guides the material to roll along its surface. This rolling motion allows each natto grain to be fully and multi-angledly exposed in the electrostatic spraying area. Compared with the "pushing" and "crushing" of the material by traditional stirring blades, this greatly increases the effective contact area and contact opportunities between the natto grains and the bacterial droplets, laying the foundation for uniform adsorption from a physical mechanism and effectively avoiding the problem of uneven local inoculation.

[0042] Example 2 A method for producing an inoculation device for natto production includes the following steps: S1. Feeding and initialization: Soybeans are pressure-cooked at 105–125℃ for 25–40 minutes until the beans can be crushed with a finger. The cooked soybeans are then allowed to cool naturally to 40–60℃ in preparation for inoculation. The cooked and cooled soybeans are fed into the tank through the feed inlet 101. The lifting platform 301 of the top-lifting gate mechanism is raised to the high position, and the drive motor 202 is started to make the material turning guide 203 rotate continuously in one direction. S2. Circulating mixing and electrostatic spraying: The material in the collection bin 107 is picked up and lifted by the first guide surface 204 of the rotating material guide component 203; After being lifted to a certain height, the material rolls down along the first guide surface 204 under the action of gravity and enters the return cavity 105 through the feed window 106. The material is temporarily stored in layers in the return chamber 105 and then slides down, eventually falling back to the collection bin 107 to complete one cycle. During this process, the electrostatic spraying system is activated. The bacterial solution (Bacillus subtilis bacterial solution) is atomized and charged by the electrostatic atomizing nozzle 401 and sprayed onto the material falling in the mixing chamber 104. S3. Online monitoring and pattern determination: The near-infrared spectral sensor 501 of the online quality monitoring system monitors the amount of bacterial liquid adhering to the material in the reflux chamber 105 in real time; The control unit continuously receives monitoring data. When it determines that the amount of bacterial liquid adhering to the substrate has reached a preset threshold and the data tends to stabilize, it generates a mode switching command. S4. Sequential material arrangement: Based on the determination result of S3, the control unit automatically executes the material feeding program, which consists of two stages: Phase 1 (Mode Switching): The control unit outputs a command to drive the lifting platform 301 to descend to the low position, opening the channel between the return chamber 105 and the collection bin 107.

[0043] Phase Two (Step-by-Step Discharge): The control unit instructs the lifting platform 301 to rise in steps and intermittently, while the material-turning guide 203 continues to rotate. With each rise of the lifting platform 301, the material accumulated at the bottom of the collection bin 107 is lifted in batches and scooped up by the second guide surface 205 of the material-turning guide 203, guided to the discharge guide plate 207, and finally discharged in an orderly manner through the discharge valve 102 until the material is emptied.

[0044] In step S2, the material forms a circulation channel between the collection bin 107, the mixing chamber 104 and the return chamber 105, and the material is temporarily stored in the return chamber 105 in a "last in, last out, layered" manner, so that all materials undergo the same number of cyclic sprays.

[0045] This production method cleverly alters the material's trajectory by utilizing the simple variable of the lifting platform 301's height, combined with a unidirectional rotating material guide 203. When the lifting platform 301 is at a high position, the material is scooped up and rolls back along the first guide surface 204 into the circulation path; when the lifting platform 301 is at a low position, the material is guided to the second guide surface 205 and slides towards the discharge port. This mode switching is entirely achieved by the functional areas of the mechanical structure itself, without the need for complex forward and reverse rotation control or additional actuators. It features a simple structure, reliable operation, and low failure rate, fundamentally solving the problem of inconvenient material discharge in traditional mixing equipment, shortening the process flow, facilitating continuous multi-batch cyclic production, and improving equipment utilization and overall production efficiency.

[0046] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An inoculation device for natto production, characterized in that, include: The tank assembly (100) has a feed inlet (101) at the top and a discharge valve (102) at the end. The interior of the tank is divided into a mixing chamber (104) and a reflux chamber (105) by an arc-shaped partition (103). The reflux chamber (105) has a feed window (106) on its side wall that communicates with the mixing chamber (104). The bottom of the reflux chamber (105) is connected to a collection bin (107) located at the bottom of the tank. The material turning and path switching mechanism includes a drive shaft (201) rotatably mounted at the center of the tank assembly (100) via a bearing seat, which is driven to rotate by a drive motor (202) fixedly mounted at the end of the tank assembly (100); a material turning guide (203) is fixedly mounted on the drive shaft (201), and the two sides of the material turning guide (203) are a first guide surface (204) and a second guide surface (205), respectively; when the two sides of the material turning guide (203) rotate with the drive shaft (201), they can periodically sweep across the upper space of the collection bin (107); The lifting gate mechanism includes a lifting platform (301) that can be slidably disposed in the collection bin (107), and a linear actuator (302) fixedly installed at the bottom of the collection bin (107). The output end of the linear actuator (302) is connected to the lifting platform (301) for driving the lifting platform (301) to rise and fall. When the lifting platform (301) rises to the high position, the side of the lifting platform (301) blocks the connection between the return cavity (105) and the collection bin (107), so that a hopper space for temporary storage of materials is formed in the collection bin (107). When the lifting platform (301) falls to the low position, the connection between the return cavity (105) and the collection bin (107) is fully opened. An electrostatic spraying system includes at least one electrostatic atomizing nozzle (401) fixedly installed on the inner wall of the tank and located above the mixing chamber (104), the electrostatic atomizing nozzle (401) being connected to an external bacterial liquid supply unit and a high-voltage electrostatic generator via a pipeline; The online quality monitoring system includes a near-infrared spectral sensor (501) fixedly installed on the wall of the reflux chamber (105). The detection window of the near-infrared spectral sensor (501) faces the internal channel of the reflux chamber (105) and is used to detect the composition information of the material flowing through it in real time.

2. The inoculation device for natto production according to claim 1, characterized in that: The material turning guide (203) is a plate-shaped component. Its first guide surface (204) and drive shaft (201) are both made of conductive material and are electrically connected. The drive shaft (201) is electrically grounded through a bearing seat.

3. The inoculation device for natto production according to claim 1, characterized in that: The first guide surface (204) of the material turning guide (203) is fixedly equipped with a flexible baffle (206), and the length direction of the flexible baffle (206) is consistent with the axis direction of the drive shaft (201).

4. The inoculation device for natto production according to claim 1, characterized in that: The second guide surface (205) of the material turning guide (203) is fixedly installed with a discharge guide plate (207). The inner wall of the discharge guide plate (207) forms an inclined working groove. The lower end of the inclined working groove points to the discharge valve (102). When the device is in the discharge mode and the material turning guide (203) rotates, its second guide surface (205) can guide the material into the inclined working groove of the discharge guide plate (207).

5. The inoculation device for natto production according to claim 1, characterized in that: The inner wall of the reflux cavity (105) is provided with a detection cavity, which is separated from the reflux cavity (105) by a glass plate (402). The detection end of the near-infrared spectral sensor (501) extends into the detection cavity.

6. The inoculation device for natto production according to claim 1, characterized in that: An electric heating tube is embedded in the tank wall of the tank assembly (100), and a temperature sensor (601) extending into the inner cavity of the tank is provided on the top of the tank assembly (100).

7. The inoculation device for natto production according to claim 1, characterized in that: The online quality monitoring system also includes a control unit electrically connected to the near-infrared spectral sensor (501), which outputs control signals to the linear driver (302) and the drive motor (202) based on the real-time monitoring data of the near-infrared spectral sensor (501).

8. A production method using an inoculation device for natto production according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Feeding and initialization: Soybeans that have been cooked and cooled to the inoculation temperature are fed into the tank through the feed inlet (101). The lifting platform (301) of the top-lifting gate mechanism is controlled to rise to the high position, and the drive motor (202) is started to make the material turning guide (203) rotate continuously in one direction. S2. Circulating mixing and electrostatic spraying: The material in the collection bin (107) is picked up and lifted by the first guide surface (204) of the rotating material guide (203); After being lifted to a certain height, the material rolls down along the first guide surface (204) under the action of gravity and enters the return chamber (105) through the feed window (106). The material is temporarily stored in layers in the return chamber (105) and slides down, eventually falling back to the collection bin (107) to complete one cycle; During this process, the electrostatic spraying system is activated. The bacterial liquid is atomized by the electrostatic atomizing nozzle (401) and charged before being sprayed onto the material falling in the mixing chamber (104). S3. Online monitoring and pattern determination: The near-infrared spectral sensor (501) of the online quality monitoring system monitors the amount of bacterial liquid adhering to the material in the reflux chamber (105) in real time; The control unit continuously receives monitoring data. When it determines that the amount of bacterial liquid adhering to the substrate has reached a preset threshold and the data tends to stabilize, it generates a mode switching command. S4. Sequential Material Discharge: Based on the determination result of S3, the control unit automatically executes the material discharge procedure, which includes two stages: Phase 1: The control unit outputs a command to drive the lifting platform (301) to descend to the low position, opening the channel between the return chamber (105) and the collection bin (107); Phase 2: The control unit instructs the lifting platform (301) to rise in stages and intermittently, while the material turning guide (203) continues to rotate. With each rise of the lifting platform (301), the material accumulated at the bottom of the collection bin (107) is lifted in batches and picked up by the second guide surface (205) of the material turning guide (203), guided to the discharge guide plate (207), and finally discharged in an orderly manner through the discharge valve (102) until the material is emptied.

9. A production method according to claim 8, characterized in that: In step S2, the material forms a circulation channel between the collection bin (107), the mixing chamber (104) and the return chamber (105), and the material is temporarily stored in the return chamber (105) in a "last in, last out, layered" manner, so that all materials undergo the same number of cyclic sprays.

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