Seedling tray cleaning machine and cleaning and disinfecting method thereof

Abstract

The invention discloses a seedling raising plate cleaning machine and a cleaning and disinfecting method thereof, and aims to solve the problems that an existing seedling raising plate is low in cleaning and disinfecting efficiency, not thorough in cleaning, prone to damage in disinfection, waste in water resources and free of continuous bacteriostasis. The cleaning machine comprises a support platform, and a tray loading mechanism, a high-temperature disinfection mechanism, a conveying system, a multi-stage collaborative cleaning system, a pesticide spraying protection system and a power and control system which are sequentially arranged on the platform; the tray loading mechanism is used for bearing seedling raising trays to be treated, the high-temperature disinfection mechanism is used for instantaneously sterilizing the falling seedling raising trays by using steam at 110-135 DEG C, the conveying system is used for conveying the seedling raising trays, the multi-stage collaborative cleaning system is used for removing residues through multi-stage'high-pressure spraying and mechanical scrubbing ', and the pesticide spraying protection system is used for spraying atomized disinfectant to form an antibacterial layer. The cleaning and disinfecting method comprises the steps of tray loading, high-temperature instantaneous sterilization, multi-stage collaborative cleaning, medicine protection and collection. Automatic treatment is achieved, the cleaning rate exceeds 96%, the sterilization rate is larger than or equal to 99.9%, water is saved by 60%, bacteriostasis lasts for 7-15 days, and the device is suitable for seedling raising plates of multiple specifications.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery technology, specifically to a seedling tray cleaning machine for automatically cleaning, disinfecting, and protecting seedling trays after use during the seedling cultivation process of crops such as tobacco, vegetables, flowers, and seedlings. It also relates to the corresponding cleaning and disinfection method for the equipment. Background Technology

[0002] In the modern agricultural seedling industry, seedling trays, as the core carrier for large-scale seedling production, are widely used in the seedling stage of crops such as tobacco, vegetables, flowers, and economic seedlings. After use, a large amount of seedling substrate (such as a mixture of peat, vermiculite, and perlite), crop roots, pathogens (such as damping-off pathogens and seedling blight pathogens), and insect eggs remain on the surface and inside the holes of the seedling trays. If they are not thoroughly cleaned and disinfected, direct reuse will lead to cross-infection of diseases and pests, seriously affecting the seedling survival rate; if they are discarded, it will cause resource waste and environmental pollution.

[0003] Currently, the cleaning and disinfection of seedling trays mainly relies on the following methods, all of which have significant drawbacks: Manual cleaning and disinfection: This method involves manually rinsing with a handheld water gun and soaking for disinfection, which is extremely inefficient (each person can process less than 500 trays per day). Furthermore, it is difficult to completely remove residual matrix from the pores. The amount of chemical agents used during disinfection is difficult to control, which can easily lead to excessive residues or incomplete disinfection. At the same time, the operators are subjected to high labor intensity and are easily harmed by high-pressure water jets and chemical agents.

[0004] Simple cleaning equipment is insufficient. Some existing small-scale cleaning equipment only has a single high-pressure water spray function and lacks a mechanical brushing structure, making it unable to remove stubborn residues inside the holes. Disinfection often relies on prolonged high temperatures (>150℃) or ultraviolet irradiation. The former easily causes deformation and damage to the plastic seedling trays, while the latter only disinfects the surface and cannot kill pathogens inside the holes. Furthermore, the cleaning water is directly discharged, resulting in significant water waste (each cleaning session consumes up to 0.5m³ of water). 3 / Thousands of plates).

[0005] Lack of continuous antibacterial protection: After the existing equipment is cleaned and disinfected, the seedling trays are easily contaminated by microorganisms in the environment again during transportation and storage, requiring secondary disinfection, which increases operating costs and complexity.

[0006] To address this issue, a seedling tray cleaning machine and its cleaning and disinfection method are proposed. Summary of the Invention

[0007] In response to the problems of "low efficiency, incomplete cleaning, easily damaged disinfection trays, water waste, and lack of continuous antibacterial properties" in the existing technologies, this invention proposes a seedling tray cleaning machine and its cleaning and disinfection method that integrates "automatic tray loading, instantaneous high-temperature disinfection, multi-level collaborative cleaning, atomized antibacterial protection, and water recycling" to meet the high-efficiency, environmentally friendly, and safe requirements of the large-scale seedling industry.

[0008] In a first aspect, the present invention provides a seedling tray cleaning machine, comprising a support platform; a tray loading mechanism disposed at one end of the support platform for holding stacked seedling trays to be treated; a high-temperature sterilization mechanism disposed below the outlet of the tray loading mechanism for instantaneously sterilizing the seedling trays falling by gravity with high-temperature steam; a conveying system disposed on the support platform for receiving and conveying the seedling trays that have undergone high-temperature sterilization; a multi-stage collaborative cleaning system disposed along the conveying path of the conveying system, the system being composed of at least two stages of cleaning units in sequence, each stage of cleaning unit including a high-pressure water spraying mechanism and a mechanical brushing mechanism located above and below the seedling tray conveying path; a spray protection system disposed at the end of the conveying system for spraying atomized disinfectant onto the cleaned seedling trays to form an antibacterial protective layer; and a power and control system for providing power to the entire equipment and realizing automated process control. With "modular integration + automated collaboration" as its core, the main support framework of the equipment is built through a support platform. The various functional mechanisms are arranged in sequence according to the "seedling tray processing flow": the tray loading mechanism uses gravity + mechanical control to achieve orderly tray supply; the high-temperature sterilization mechanism completes instant sterilization by wrapping the falling seedling trays with annular steam; the conveying system ensures smooth connection between each link with adjustable speed conveying; the multi-level collaborative cleaning system removes residues through a two-way combination of "high-pressure spraying + mechanical brushing"; the spraying protection system forms a uniform antibacterial layer with atomization technology; and the power and control system achieves unmanned operation of the entire process through closed-loop regulation by a central controller and sensors.

[0009] Furthermore, to address the issue of "stubborn adhesion" of residual substrate inside the seedling tray holes, the mechanical brushing mechanism employs multiple independently driven brushes. By adjusting the brush speed, the bristles penetrate deep into the holes. Combined with the "pre-rinse + post-wash" of the high-pressure water spray mechanism, a composite cleaning force of "physical peeling + water flow rinsing" is formed. At the same time, the brushes arranged vertically can clean both sides of the seedling tray simultaneously, avoiding omissions in single-sided cleaning.

[0010] Furthermore, the high-temperature sterilization mechanism includes a steam generator and steam nozzles arranged around the tray drop channel to ensure that the seedling trays are fully enveloped during the drop process. Utilizing "high-temperature steam instantaneous sterilization" technology, the steam generator outputs high-temperature steam at 110℃-135℃ and 0.3-0.5MPa, which forms a 360° steam-enclosed zone without dead angles through the annular steam nozzles surrounding the tray drop channel. Under the action of gravity, the seedling trays pass through the steam zone at a speed of 0.2m / s, achieving simultaneous sterilization of the "surface + pores" within 2-10 seconds. The instantaneous high temperature also prevents the plastic seedling trays (heat resistance temperature ≥140℃) from deforming due to prolonged heat exposure.

[0011] Furthermore, it also includes a water circulation treatment system for collecting, filtering, and reusing the cleaning water used by the high-pressure water spraying mechanism after sedimentation. By constructing a "cleaning water closed-loop circulation" system, the wastewater from the high-pressure water spraying mechanism is collected through a collection tank under the support platform. The wastewater first enters the filtration tank and is filtered through a 50-mesh stainless steel filter to remove large particles of substrate (such as peat blocks and residual roots). Then, it passes through a sedimentation zone to remove fine suspended solids. The treated clean water is returned to the high-pressure water pump for reuse. At the same time, the final spray uses clean water to avoid trace amounts of residue in the recycled water adhering to the surface of the seedling trays.

[0012] Furthermore, the spraying protection system includes a precision metering pump and an ultrasonic atomizing nozzle, the ultrasonic atomizing nozzles being arranged in pairs above and below the seedling tray transport path.

[0013] Furthermore, the support platform is equipped with several sensors for detecting seedling trays, and the bottom of the support platform is equipped with casters. The sensors (position sensors and photoelectric sensors) on the support platform detect the "existence status" and "transmission position" of the seedling trays in real time: the position sensors monitor the remaining number of seedling trays in the tray loading mechanism (triggering a tray replenishment alarm when less than 2 are available), and the photoelectric sensors detect whether the seedling trays on the conveying system are stuck or offset, ensuring stable tray supply and smooth conveying at each stage; the bottom casters are made of polyurethane material with a brake structure, which facilitates the movement of the equipment in the seedling workshop and can also fix the equipment during operation to prevent vibration from causing misalignment of the mechanism.

[0014] A second aspect of the present invention provides a method for cleaning and disinfecting seedling trays, using the seedling tray cleaning machine described above, comprising the following steps: Step 1, tray loading: Stack multiple seedling trays into the tray loading mechanism; Step 2, High-Temperature Instant Sterilization: The seedling trays pass through the high-temperature sterilization zone in sequence under the action of gravity, and are instantly treated by high-temperature steam to kill surface pathogens; Step 3, Multi-stage Co-cleaning: The sterilized seedling trays are transported by the conveyor system and undergo a multi-stage co-processing process of "high-pressure spraying followed by mechanical brushing" to thoroughly remove residues from the surface and pores. Step 4, Drug Protection: Before outputting the cleaned seedling trays, spray them with atomized disinfectant to coat their surface with a protective film of disinfectant that has a continuous antibacterial effect. Step 5: Collection: The processed seedling trays are transported to the collection area for air drying or packaging.

[0015] This method follows the process logic of "orderly tray feeding → instantaneous sterilization → graded cleaning → antibacterial protection → centralized collection", transforming the actions of each functional mechanism of the equipment into standardized steps: the tray feeding stage achieves batch tray feeding through mechanical control; the high-temperature sterilization stage utilizes gravity falling and steam wrapping simultaneously; the multi-stage cleaning stage uses "high pressure + brushing" gradient cleaning; the drug protection stage uses atomization to form a long-lasting antibacterial layer; and the collection stage completes the processing loop through air drying / packaging. Each step is seamlessly connected through the speed adjustment of the conveyor system (0.3-0.8m / s).

[0016] Further describing the aforementioned scheme, in step two, the temperature of the high-temperature steam is 110°C to 135°C, and the processing time is 2 to 10 seconds. The appropriate combination of temperature and time achieves the dual goals of "high-efficiency sterilization + low-damage trays".

[0017] Further describing the aforementioned scheme, in step three, the water pressure of the high-pressure spray can be adjusted between 5MPa and 20MPa according to the degree of dirt, and the last stage of spraying uses clean water for rinsing.

[0018] Further description of the aforementioned scheme: In step four, the atomized disinfectant is a food-grade peracetic acid or chlorine dioxide solution; the method also includes automatically adjusting the cleaning water pressure, brush roller speed, steam temperature, and disinfectant spraying volume through a central control system based on a preset program or sensor feedback.

[0019] Compared with the prior art, the present invention has the following significant advantages: Significantly improved efficiency: The entire process is automated, requiring no human intervention. A single machine can process 8,000-10,000 trays per day, equivalent to the workload of 10-15 people, greatly reducing labor intensity. High cleaning thoroughness: The three-stage "high-pressure spray + mechanical brushing" treatment, combined with the upper and lower bidirectional cleaning structure, can thoroughly remove stubborn substrate residues from the surface and holes of the seedling tray, with a cleaning rate of over 96%. Disinfection is safe and reliable: Instantaneous high-temperature steam disinfection at 110℃-135℃ ensures the elimination of pathogens (sterilization rate ≥99.9%), while avoiding deformation of the seedling trays due to prolonged high temperatures (plastic seedling trays have a heat resistance temperature ≥140℃), leaving no residue after disinfection; High-efficiency water resource utilization: Through a water recycling system, the water reuse rate for cleaning reaches over 70%, and the water consumption per cleaning cycle is reduced to 0.15m³. 3 / Thousands of pans, saving 60% more water than existing equipment; Continuous antibacterial protection: The antibacterial protective layer formed by the atomized disinfectant can continuously inhibit bacteria on the surface of the seedling tray for 7-15 days, avoiding secondary pollution during transportation and storage, and eliminating the need for secondary disinfection; Highly adaptable: The conveying speed, water pressure, brush rotation speed and other parameters can be adjusted through the central controller to adapt to different specifications (50 holes, 72 holes, 128 holes) of plastic seedling trays, and the universal wheels at the bottom of the equipment make it easy to move to different seedling workshops. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is an overall schematic diagram provided for an embodiment of the present invention; Figure 2 A front view diagram provided for an embodiment of the present invention; Figure 3 This is a schematic diagram of the tray loading mechanism provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the multi-stage collaborative cleaning system provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the spray protection system provided in an embodiment of the present invention.

[0022] The following are the labeling elements in the figure: 1. Loading mechanism; 11. Cylinder; 12. Insert block; 13. Housing; 14. Sensor; 15. Frame; 2. High-temperature disinfection mechanism; 3. Conveying system; 4. Multi-stage collaborative cleaning system; 41. High-pressure water spraying mechanism; 411. Water pump; 412. Nozzle; 413. Filter tank; 414. Drawer; 42. Mechanical brushing mechanism; 421. Brush; 5. Spray protection system; 51. Connecting pipe; 52. Upper spray pipe; 53. Lower spray pipe; 6. Support platform; 61. Casters; 62. Baffle.

[0023] The accompanying drawings have illustrated specific embodiments of the invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] To make the technical solution, implementation process, and technical effects of the present invention clearer and more explicit, the following description is in conjunction with the appendix. Figure 1-5 This invention provides a detailed description of the seedling tray cleaning machine and its cleaning and disinfection method, along with specific engineering application data. This embodiment is only for explaining the invention and is not intended to limit the scope of protection of the invention. The seedling tray cleaning machine of this invention adopts a "modular integration + automated collaboration" core design concept. Based on a support platform 6, an overall support frame is built. Each functional mechanism is sequentially connected according to the "seedling tray processing flow," forming a continuous operation line of "tray loading → sterilization → cleaning → antibacterial → collection." It can be widely applied to the cleaning and disinfection of seedling trays for crops such as tobacco, vegetables, flowers, and seedlings, effectively solving the problems of low efficiency, incomplete cleaning, easily damaged trays during disinfection, water waste, and lack of continuous antibacterial properties in existing technologies. The support platform 6, as the main load-bearing structure of the equipment, needs to balance stability, corrosion resistance, and mobility. In this embodiment, Q235 cold-rolled steel plate is used as the base material, which is formed by laser cutting, CNC bending, and welding. The bottom of the platform is equipped with several sets of polyurethane casters 61, and each set of casters 61 is equipped with double brake pads. The braking method is foot-operated mechanical braking, which facilitates the movement of the equipment in the seedling workshop and can be completely fixed during operation to avoid vibration causing misalignment of the mechanism. In addition, the support platform 6 has reserved space for wiring and pipe laying, with three longitudinal wiring holes for the concealed arrangement of power cables, sensor signal lines and air pipes, keeping the equipment appearance clean; two detachable maintenance doors are set under the platform to facilitate regular maintenance of components such as the water circulation treatment system and power motor. Each functional module is arranged sequentially along the length of the support platform 6. The tray loading mechanism 1 is fixed to the input end of the support platform 6. The center line of the tray dropping channel of the tray loading mechanism 1 is precisely aligned with the center line of the entrance of the subsequent high-temperature sterilization mechanism 2 to avoid deviation and jamming when the seedling trays fall. like Figure 3As shown, the frame 15 of the tray loading mechanism 1 is made of 304 stainless steel, and release devices are provided at the four corners. The release devices include a cylinder 11, a plug 12, a shell 13, and a sensor 14. The sensor 14 detects the presence or absence of the seedling tray in real time. The cylinder 11 drives the plug 12 to block or release the seedling tray. The shell 13 encloses the cylinder 11 and the plug 12. The high-temperature sterilization unit 2 is located directly below the outlet of the tray loading mechanism 1. Its top is connected to the tray dropping channel of the tray loading mechanism 1 through a flange. The sealing gasket is made of silicone rubber gasket with a temperature resistance of 200℃ to ensure minimal steam leakage. The bottom of the high-temperature sterilization unit 2 is fixed above the platform surface by a bracket to ensure that the seedling trays are completely enclosed in the steam zone during the falling process, achieving all-round sterilization. like Figure 4 As shown, the multi-level collaborative cleaning system 4 is set along the transmission path of the conveying system 3, and includes a total of 3 cleaning units. The high-pressure water spraying mechanism 41 and the mechanical brushing mechanism 42 of each cleaning unit are arranged symmetrically up and down to ensure that the front and back of the seedling tray are processed simultaneously without any cleaning dead corners. like Figure 5 As shown, the spray protection system 5 is installed at the end of the conveyor system 3. Its upper spray pipe 52 and lower spray pipe 53 are fixed to the upper and lower parts of the conveyor belt by brackets to avoid spray blind spots. The central controller (PLC) of the power and control system is installed in the electrical control box, and the touch screen is embedded in the front of the electrical control box, which makes it easy for operators to set parameters and monitor the operating status. The power motors are all installed on motor mounts under the platform. The motor mounts are connected to the platform frame through shock-absorbing pads, which can significantly reduce operating noise. like Figure 3 As shown, the tray loading mechanism 1, acting as the "feeding end" of the equipment, needs to achieve orderly stacking and intermittent tray feeding of seedling trays. In this embodiment, a combination structure of "cylinder 11 drive + photoelectric monitoring" ensures the stability and accuracy of tray feeding. Cylinder 11 is a standard SC63×50 double-acting cylinder with a rated working pressure of 0.4-0.6MPa. The piston rod end is connected to the insert block 12 via a floating joint. The cylinder 11 is installed horizontally, perpendicular to the side of the tray loading mechanism 1. The insert block 12, as the core component supporting the seedling trays, is injection molded from nylon 66 + 30% glass fiber, possessing high strength and wear resistance, and can withstand the weight of the seedling trays for a long time without easily deforming. The insert block 12 has a 15° inclination angle on its inner side, facilitating smooth disengagement of the seedling trays when they fall, preventing tray jamming. It should be noted that cylinder 11 can be replaced with a motor if needed. In this embodiment, sensor 14 is a diffuse reflection photoelectric sensor, model Omron E3F-DS30C4, with a detection distance of 0-300mm and a response time ≤1ms. It is installed inside the tray loading mechanism 1, with the sensor probe facing the stacked seedling trays, to monitor the remaining number of seedling trays in the tray loading mechanism 1 in real time. When the number of seedling trays is less than 2, sensor 14 outputs a signal to the central controller, triggering an audible and visual alarm, which can promptly remind the operator to replenish the trays and avoid the equipment running idle. The tray feeding process of the tray loading mechanism 1 is automatically controlled by the central controller. Initially, cylinder 11 is extended, and insert block 12 extends into frame 15 to support the stacked seedling trays. The bottom of the lowest seedling tray is in close contact with the upper surface of insert block 12. When the photoelectric sensor of conveyor system 3 detects that there are no seedling trays on the conveyor belt, the central controller sends a signal to cylinder 11, controlling cylinder 11 to retract in 0.1 seconds. Insert block 12 then disengages from its supporting position. The lowest seedling tray falls along the guide groove of frame 15 under gravity at a speed of approximately 0.2 m / s, precisely entering the tray dropping channel of high-temperature sterilization mechanism 2. After the seedling tray falls, cylinder 11 immediately extends in 0.1 seconds, and insert block 12 resets to support the remaining seedling trays. Simultaneously, sensor 14 detects the remaining number of trays; if the number is insufficient, a tray replenishment alarm is triggered. In this embodiment, the tray feeding interval of the tray loading mechanism 1 can be adjusted by the central controller, ranging from 2 to 5 seconds. The high-temperature sterilization unit 2 employs "instantaneous high-temperature steam envelopment" technology to efficiently kill pathogens on the surface and inside the holes of the seedling trays, while preventing deformation of the plastic seedling trays due to prolonged heating. The steam generator is an LDR0.05-0.7 type electric heating steam generator, with steam temperature precisely adjustable within the range of 110℃-135℃. It has a power supply specification of 380V / 50Hz and a power of 18kW, enabling continuous and stable output of high-temperature steam. The steam generator and the high-temperature sterilization unit 2 are connected by DN25 304 stainless steel pipes. Pressure regulating valves and temperature sensors are installed on the pipes to monitor steam parameters in real time and feed the data back to the central controller for closed-loop control. The steam temperature is set between 110℃ and 135℃. For tobacco seedling trays, which are heavily contaminated and contain many root residues after use, the temperature is set at 130℃-135℃; for vegetable seedling trays, which are moderately contaminated, the temperature is set at 120℃-125℃; and for flower seedling trays, which are lightly contaminated, the temperature is set at 110℃-115℃. Temperature control is achieved through a closed-loop adjustment between the steam generator's electric heating element and the temperature sensor. When the temperature sensor detects that the steam temperature is lower than the set value, the controller activates the heating element to increase steam output; when the temperature is higher than the set value, the heating element is deactivated to reduce steam output. The temperature fluctuation range is strictly controlled within ±2℃ to ensure stable sterilization results. The seedling trays remain in the steam zone for 2-10 seconds, specifically controlled by the speed of the conveyor system 3 and the length of the tray drop channel. The tray drop channel is 300mm long, and the seedling trays fall at a speed of 0.2m / s (determined by the tray feeding interval of the tray loading mechanism 1). The theoretical dwell time is 1.5 seconds. Simultaneously, the input speed of the conveyor system 3 is matched with the falling speed and maintained at 0.2m / s to ensure that the seedling trays continue to be subjected to the subsequent steam after entering the conveyor belt. The total processing time can be extended to 2-10 seconds by adjusting the conveyor belt speed. The slower the speed, the longer the processing time, which can be flexibly adjusted according to the degree of pathogen contamination. To ensure safe operation of the equipment and prevent damage to the seedling trays, the high-temperature sterilization mechanism 2 is equipped with multiple safety protection measures. When the steam pressure exceeds 0.7 MPa, the safety valve of the steam generator automatically releases pressure to prevent pipe rupture. If the temperature sensor detects a temperature exceeding 140°C (the heat resistance limit of the plastic seedling trays), the controller immediately cuts off the power to the steam generator and triggers an alarm to prevent deformation of the seedling trays. Verified by a third-party testing agency, the high-temperature sterilization mechanism 2 in this embodiment achieves a sterilization rate of ≥99.9% against damping-off and seedling blight pathogens, and the deformation rate of the treated seedling trays is ≤0.5%, far lower than the 5% deformation rate of existing equipment. This effectively extends the service life of the seedling trays while ensuring sterilization effectiveness. like Figure 4 As shown, the multi-stage collaborative cleaning system 4 is the "core cleaning unit" of the equipment. Through the combined action of "high-pressure spraying + mechanical brushing," it thoroughly removes residual substrate from the surface and holes of the seedling tray. This embodiment sets up three cleaning units, with high-pressure water spraying mechanism 41 and mechanical brushing mechanism 42 symmetrically arranged above and below each unit, forming an all-round, dead-angle-free cleaning effect. Each cleaning unit of the high-pressure water spraying mechanism 41 is equipped with one CDL2-16 high-pressure centrifugal pump 411, with a rated pressure of 25MPa and a flow rate of 2m³ / h. 3 The high-pressure water pump 411 operates at 380V / 50Hz with a power output of 3kW, providing a powerful water flow to effectively remove residual substrate from the surface of the seedling trays. The inlet of the high-pressure water pump 411 connects to the water circulation system, while the outlet connects to the nozzle 412 via a high-pressure hose, ensuring stable and leak-free high-pressure water flow. The nozzle 412 is a fan-shaped high-pressure nozzle with a spray angle of 45°. Each cleaning unit has 12 nozzles 412 above and 8 below, installed at a 30° angle to the seedling tray surface to ensure deep penetration into the holes and removal of stubborn residue. The nozzle 412 is connected to the high-pressure hose via a quick-connect coupling for easy disassembly and cleaning. If a nozzle 412 becomes clogged, it can be quickly replaced without affecting normal equipment operation. The water circulation treatment system consists of a collection tank, a filter tank 413, a drawer 414, a clean water tank, and a clean water pump, enabling the recycling of cleaning water and significantly saving water resources. The collection tank is located below the conveying system 3, with a 5° slope at the bottom to facilitate wastewater collection to the outlet and improve collection efficiency. The filter tank 413 is divided into a coarse filtration zone and a fine filtration zone. The coarse filtration zone is equipped with a 50-mesh stainless steel filter screen (1mm thick) to filter large particles (such as peat blocks and root residues), preventing large impurities from entering subsequent pipes and causing blockages. The fine filtration zone is equipped with a 100-mesh nylon filter screen (0.5mm thick) to filter fine suspended solids, further purifying the water. The drawer 414 is a removable residue collection drawer located below the coarse filtration zone, used to collect large particles of residue intercepted by the filter screen. A handle is provided on the outside of the drawer 414 for easy regular cleaning to ensure the filter screen remains clear. The mechanical brushing mechanism 42 has three brush rollers 421 arranged above and three brush rollers 421 arranged below each cleaning unit, corresponding one-to-one with the brush rollers 421 above, ensuring that both sides of the seedling tray are thoroughly brushed. Each brush roller 421 is equipped with a 60W DC motor, and the speed can be adjusted within the range of 0-1500r / min. The motor and the brush roller 421 are connected by a coupling made of elastic rubber, which can play a role in shock absorption and noise reduction, reducing the noise during equipment operation. The three-stage cleaning unit employs a "gradient cleaning" strategy, with parameters at each stage adapted to the degree of soiling, progressively removing residual substrate from the seedling trays to ensure thorough cleaning. The first stage is a coarse washing unit, primarily used to remove large pieces of substrate residue from the surface of the seedling trays. The high-pressure spray is set at 15-20 MPa, providing strong water flow impact to quickly remove loose residue from the surface. The mechanical brushes are set to a rotation speed of 1200-1500 r / min, using high-speed rotating bristles to remove stubborn residue from the pores, laying the foundation for subsequent fine washing. The water source is recycled water from a water recycling system, treated by coarse and fine filtration, which meets the needs of coarse washing while conserving water resources. The second stage is the fine washing unit, used to remove the fine substrate residue left from the first stage. The high-pressure spray water pressure is set at 10-15MPa, resulting in a finer water flow that penetrates deep into the pores to remove fine residue. The mechanical brush 421 rotates at 1000-1200 rpm to further clean the residue deep within the pores, ensuring no obvious residue remains. The water source is still recycled water from the water circulation system, but after secondary fine filtration, the water quality is cleaner, preventing impurities from re-adhering to the surface of the seedling trays. The third stage is the rinsing unit, used for the final cleaning of the seedling trays, ensuring no residue remains on the surface. The high-pressure spray water pressure is set at 8-10MPa, using clean water to prevent trace residues from recycled water from adhering to the surface of the seedling trays and affecting subsequent seedling cultivation. The mechanical brush 421 rotates at 800-1000 rpm, gently brushing to ensure the surface of the seedling trays is clean while avoiding excessive brushing that could damage them. The water source is a separate clean water tank, isolated from the recycled water system, ensuring the cleanliness of the rinsing water. In this embodiment, the water pressure of the high-pressure water spray mechanism 41 and the rotation speed of the mechanical brushing mechanism 42 can be automatically adjusted by the central controller based on sensor feedback. When the photoelectric sensor detects heavy dirt on the seedling tray (judged by reflectivity), the controller automatically increases the water pressure and the rotation speed of the brush 421 to enhance cleaning power; when the dirt is light, the parameters are reduced to save energy, achieving intelligent cleaning. Testing showed that the seedling tray cleanliness rate after three-stage coordinated cleaning reached over 97%, and the removal rate of residual substrate in the holes reached 96%, fully meeting the needs of subsequent seedling cultivation.

[0026] The spray protection system 5 forms an antibacterial protective layer on the surface of the cleaned seedling trays, preventing secondary contamination during transportation and storage. This embodiment employs "ultrasonic atomization + precision metering" technology to ensure uniform adhesion of the disinfectant, resulting in a continuous and effective antibacterial effect. The precision metering pump can be a JX-type plunger metering pump with a rated flow rate of 0.1-1 L / h, a working pressure of 0.3 MPa, and a flow accuracy of ±1%. The flow rate can be precisely adjusted via a 4-20mA signal from the central controller, ensuring a stable disinfectant spray volume that avoids both over-spraying, waste, and residue, and under-spraying, which would negatively impact the antibacterial effect. The connecting pipe 51 is made of DN15 304 stainless steel, with its outlets connected to the upper spray pipe 52 and the lower spray pipe 53 respectively, to achieve disinfectant diversion. A pressure gauge and a shut-off valve can be installed on the connecting pipe 51 for easy monitoring and control of the liquid pressure, ensuring stable atomization. Both the upper spray pipe 52 and the lower spray pipe 53 are made of DN20 304 stainless steel. The upper spray pipe 52 is installed above the conveyor system 3, and the lower spray pipe 53 is installed below the conveyor belt, arranged symmetrically to ensure uniform spraying of disinfectant on both sides of the seedling trays. Ultrasonic atomizing nozzles are evenly distributed on the spray pipes. The disinfectant solutions mainly include food-grade peracetic acid solution and chlorine dioxide solution. The food-grade peracetic acid solution has a concentration of 0.2%, prepared by diluting a 15% concentrate solution at a ratio of 1:74 (1L of concentrate to 74L of purified water). It has broad-spectrum bactericidal properties, effectively killing bacteria, fungi, and viruses. It also degrades rapidly, breaking down into acetic acid and water within 24 hours, leaving no residue and ensuring high safety. The chlorine dioxide solution has a concentration of 500mg / L, prepared by diluting a 2000mg / L concentrate solution at a ratio of 1:3. It exhibits good stability, long-lasting antibacterial effect, and does not corrode the seedling tray material, effectively protecting the trays. Spraying parameters are flexibly adjusted according to the conveyor belt speed. When the speed is 0.5m / s, the spray rate is set to 15-20mL / m. 2 The flow rate is controlled by a metering pump at 0.5-0.8 L / h to ensure that the disinfectant forms a uniform protective layer on the surface of the seedling trays, with a thickness of approximately 5-10 μm. The atomization pressure is set at 0.2-0.3 MPa, monitored by a pressure gauge on connector 51. Excessive pressure leads to larger atomized particles and uneven spraying, while insufficient pressure results in poor atomization and inadequate disinfectant coverage; therefore, the pressure range must be strictly controlled. Third-party testing shows that the antibacterial protective layer formed after spraying can maintain antibacterial activity for 7-15 days. Under conditions of 25℃ and 70% humidity, the bacterial count on the surface of the seedling trays is ≤10 CFU / tray after 14 days. This effectively prevents secondary contamination of the seedling trays during transportation and storage, eliminating the need for secondary disinfection and reducing operating costs and complexity. To ensure operator safety and environmental friendliness, the spray protection system 5 is equipped with multiple safety protection measures. The disinfectant tank is equipped with a ventilation opening and an activated carbon filter, which can effectively adsorb the gas volatilized by the disinfectant and prevent it from leaking into the surrounding environment, thus protecting the health of the operators. The spray protection system 5 is also equipped with a baffle 62. The power and control system is responsible for providing power to each module and achieving fully automated control of the entire process, ensuring stable and efficient operation of the equipment. The power system's power module adopts a 380V / 50Hz three-phase four-wire main power supply, equipped with a 10kVA regulated power supply, which effectively stabilizes the voltage and prevents voltage fluctuations from damaging the electrical components of the equipment. The central controller of the control system uses a Siemens S7-200 SMART SR40 PLC, featuring 24 digital inputs, 16 digital outputs, 4 analog inputs, and 2 analog outputs, meeting the control requirements of various sensors and actuators with fast processing speed and high stability. In terms of parameter settings, key parameters such as cleaning water pressure, brush speed (421), steam temperature, conveyor belt speed, and disinfectant spray volume can be set. Multiple parameter formulas can be stored to adapt to seedling trays of different specifications and contamination levels, eliminating the need for repeated settings. For status monitoring, the system displays the real-time operating status of each module (e.g., motor operation, cylinder 11 operation, disinfectant level, steam temperature and pressure), and uses indicator lights to distinguish between normal operation (green), fault (red), and standby (yellow) states, allowing operators to promptly monitor equipment operation. The sensor system includes various types of sensors: position sensors (diffuse reflection photoelectric sensors, proximity switches) monitor the number of seedling trays and the position of cylinder 11 to ensure accurate tray feeding; temperature sensors (PT100 platinum resistance thermometers) monitor steam and cleaning water temperatures for closed-loop temperature control; pressure sensors (piezoelectric pressure sensors) monitor steam, water, and air pressure to ensure stable pressure; and photoelectric sensors (through-beam photoelectric sensors) monitor the seedling tray transmission position and for jams to ensure smooth transmission. The alarm system includes audible and visual alarm lights (red LED lights + buzzer) and touch screen alarm prompts. Alarm types are divided into emergency alarms and warning alarms. Emergency alarms, such as steam overheating and motor overload, will immediately stop the equipment after being triggered to prevent the accident from escalating. Warning alarms, such as insufficient seedling trays and insufficient disinfectant, will continue to run after being triggered, only reminding the operator to handle the situation, without affecting the production progress. During the tray loading stage, the operator places the stacked seedling trays into the tray loading mechanism 1. After the sensor 14 detects the seedling tray, it sends a signal to the controller. The controller then controls the cylinder 11 to extend, and the insert block 12 supports the seedling tray, completing the tray loading preparation. When the conveying system 3 needs the seedling tray, the controller controls the cylinder 11 to retract, and the seedling tray falls into the high-temperature sterilization mechanism 2. Subsequently, the cylinder 11 resets, and the tray supply continues. During the high-temperature instantaneous sterilization stage, after the seedling tray enters the tray dropping channel, the temperature and pressure sensors monitor the steam parameters in real time to ensure that the steam temperature and pressure meet the set values. If the parameters are abnormal, the controller adjusts the operating status of the steam generator. At the same time, the photoelectric sensor monitors whether the seedling tray has passed through the steam zone to ensure that each seedling tray is fully sterilized. After sterilization, the seedling tray falls into the conveying system 3 to enter the next stage of processing. In the multi-stage collaborative cleaning phase, the conveyor system 3 transports the seedling trays to each cleaning unit. The controller adjusts the pressure of the high-pressure water pump 411 and the rotation speed of the brush 421 based on preset parameters or sensor feedback regarding the degree of soiling. The first stage of coarse cleaning removes large residues, the second stage of fine cleaning removes small residues, and the third stage of rinsing ensures cleanliness. A water circulation system operates simultaneously, collecting cleaning wastewater, filtering it, and reusing it. Water replenishment is triggered when the clean water tank level is insufficient. During the cleaning process, photoelectric sensors monitor the position of the seedling trays to ensure sufficient processing time in each cleaning unit. In the drug protection phase, the cleaned seedling trays are transported to the spraying area. The controller adjusts the metering pump flow rate based on the conveyor belt speed to ensure accurate spraying. Ultrasonic atomizing nozzles atomize the disinfectant and spray it evenly onto both sides of the seedling trays. Simultaneously, a level sensor monitors the disinfectant tank level, triggering replenishment when insufficient. If spraying parameters are abnormal, the controller stops spraying and sounds an alarm to prevent affecting the antibacterial effect. During the collection stage, the seedling trays treated with pesticide are transported to the collection area, where a drying device (composed of an axial flow fan and a heating pipe, with the temperature set at 40-50℃ and the wind speed at 2m / s) is installed to quickly dry the seedling trays, ensuring that the surface disinfectant is dry and forming a stable antibacterial protective layer. The dried seedling trays can be directly packaged or transported to the storage rack via the conveyor system 3 to complete the entire processing procedure. In summary, the seedling tray cleaning machine and its cleaning and disinfection method of the present invention effectively solve the problems existing in the prior art, meet the high efficiency, environmental protection and safety requirements of the large-scale seedling industry, and have broad application prospects and promotion value. Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the foregoing claims. It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A seedling tray cleaning machine, characterized in that: Including the support platform (6). The tray loading mechanism (1) is located at one end of the support platform (6) and is used to hold the stacked seedling trays to be treated; The high-temperature sterilization mechanism (2) is located below the outlet of the tray loading mechanism (1) and is used to perform high-temperature steam instantaneous sterilization on the seedling trays that fall by gravity. The conveying system (3) is located on the support platform (6) and is used to receive and transport the seedling trays that have been sterilized at high temperature. A multi-level collaborative cleaning system (4) is set along the conveying path of the conveying system (3). The system consists of at least two cleaning units in sequence. Each cleaning unit includes a high-pressure water spraying mechanism (41) and a mechanical brushing mechanism (42) located above and below the seedling tray conveying path. The spraying protection system (5) is located at the end of the conveying system (3) and is used to spray atomized disinfectant onto the cleaned seedling trays to form an antibacterial protective layer. Power and control systems are used to provide power to the entire equipment and to automate process control.

2. The seedling tray cleaning machine according to claim 1, characterized in that: The mechanical brushing mechanism (42) uses multiple brushes (421) with adjustable rotation speed.

3. The seedling tray cleaning machine according to claim 1, characterized in that: The high-temperature sterilization mechanism (2) includes a steam generator and steam nozzles arranged around the drop plate channel.

4. The seedling tray cleaning machine according to claim 1, characterized in that: It also includes a water circulation treatment system for collecting, filtering and reusing the cleaning water used by the high-pressure water spray mechanism (41) after sedimentation. The water circulation treatment system includes a filter tank (413) and a drawer (414). The filter tank (413) is located in the drawer (414), and the drawer (414) is provided with several filter screens.

5. A seedling tray cleaning machine according to claim 1, characterized in that: The spraying protection system (5) includes a precision metering pump and an ultrasonic atomizing nozzle. The ultrasonic atomizing nozzles are arranged in pairs above and below the seedling tray transmission path. The spraying protection system (5) includes a connecting pipe (51), an upper spray pipe (52) and a lower spray pipe (53). The ultrasonic atomizing nozzles are respectively located on the upper spray pipe (52) and the lower spray pipe (53).

6. The seedling tray cleaning machine according to claim 1, characterized in that: The support platform (6) is equipped with several sensors for detecting seedling trays. The bottom of the support platform (6) is equipped with casters (61) and baffles (62). The tray loading mechanism (1) includes a cylinder (11), a plug (12), a shell (13) and a frame (15). The cylinder (11) drives the plug (12) to block or release the seedling tray. The shell (13) encloses the cylinder (11) and the plug (12).

7. A method for cleaning and disinfecting seedling trays, using a seedling tray cleaning machine as described in any one of claims 1 to 6, characterized in that, Includes the following steps: Step 1, tray loading: Stack multiple seedling trays inside the frame (15) of the tray loading mechanism (1); Step 2, High-temperature instantaneous sterilization: The seedling trays pass through the high-temperature sterilization zone of the high-temperature sterilization mechanism (2) under the action of gravity, and are instantly treated by high-temperature steam to kill surface pathogens; Step 3, Multi-level Cooperative Cleaning: The sterilized seedling trays are transported by the conveying system (3) and undergo a multi-level cooperative treatment process of "high-pressure spraying followed by mechanical brushing" to thoroughly remove the residues on the surface and in the holes. The high-pressure spraying is achieved by the water pump (411) and nozzle (412) of the high-pressure water spraying mechanism (41), and the mechanical brushing is achieved by the brush (421) of the mechanical brushing mechanism (42). The wastewater generated during the cleaning process is filtered by the filter pool (413) of the water circulation treatment system and the residue is collected by the drawer (414) for reuse. Step 4, Drug Protection: Before outputting the cleaned seedling trays, the atomized disinfectant spraying area of ​​the spray protection system (5) is diverted through the connecting pipe (51) to the upper spray pipe (52) and lower spray pipe (53) arranged vertically, and the ultrasonic atomizing nozzle sprays the atomized disinfectant, so that a layer of disinfectant protective film with continuous antibacterial effect is attached to its surface. Step 5: Collection: The processed seedling trays are transported to the collection area for air drying or packaging.

8. The method for cleaning and disinfecting seedling trays according to claim 7, characterized in that, In step two, the temperature of the high-temperature steam is 110°C to 135°C, and the processing time is 2 to 10 seconds.

9. The method for cleaning and disinfecting seedling trays according to claim 7, characterized in that, In step three, the water pressure of the high-pressure spray can be adjusted between 5MPa and 20MPa according to the degree of dirt, and the last stage of spraying uses clean water for rinsing.

10. A method for cleaning and disinfecting seedling trays according to claim 7, characterized in that, In step four, the atomized disinfectant is a food-grade peracetic acid or chlorine dioxide solution; the method also includes automatically adjusting the cleaning water pressure, brush (421) speed, steam temperature and disinfectant spraying volume through a central control system based on a preset program or sensor feedback.

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