A rapid fermentation system for organic fertilizer

Abstract

The present application belongs to the technical field of organic fertilizer production, and discloses a rapid fermentation system for organic fertilizer, which comprises a closed fermentation tank, a central screw stirring device for vertically lifting materials and a multi-layer tangential aeration device for forming horizontal rotating airflow are arranged in the closed fermentation tank, and the two devices work together to make the materials in a three-dimensional spiral fluidized state; an intelligent control unit which is based on the parameters collected by sensors and their change rates, and uses a fuzzy control algorithm to predictively and adaptively regulate the fermentation process; and an integrated circulation system which re-mixes the collected percolate into the aeration airflow through atomizing injection devices, and preheats fresh intake air through a heat exchanger using the discharged high-temperature waste gas. Through the collaborative innovation of structure and control, the present application realizes efficient and uniform fermentation of the materials, and completes the closed-loop circulation of energy and nutrients, and has the advantages of fast fermentation speed, low energy consumption and no secondary pollution.

Description

Technical Field

[0001] This invention belongs to the field of organic fertilizer production technology, specifically relating to a rapid fermentation system for organic fertilizer. Background Technology

[0002] With the development of modern agriculture and the circular economy, converting organic waste into high-quality organic fertilizer has become an important trend. Traditional composting fermentation cycles can take several months, require a large area, and are prone to producing odors and leachate pollution. To solve these problems, mechanized rapid fermentation systems have emerged, typically using closed fermentation tanks or fermentation vessels equipped with stirring, aeration, and temperature control devices, which can shorten the fermentation cycle to a few days.

[0003] However, in the process of realizing this invention, the inventors discovered that existing rapid fermentation systems have at least the following problems: 1. Traditional stirring devices (such as paddle-type and tumbling-type) are difficult to handle high-viscosity and high-density materials, and are prone to forming dead zones and caking layers inside the tank. At the same time, bottom aeration methods are prone to airflow short-circuiting, uneven oxygen distribution, and some areas are still in an anaerobic state, which affects fermentation efficiency and final product quality.

[0004] 2. To achieve rapid heating and maintain high temperatures, the system often relies on high-power electric heating, resulting in huge energy consumption. Its control system is mostly based on simple threshold switching logic, passively responding to the current values ​​of parameters such as temperature and humidity. It cannot perform fine-grained and forward-looking control based on the complex biochemical process of fermentation, leading to energy waste and insufficient process optimization.

[0005] 3. The leachate produced during fermentation is rich in nutrients such as nitrogen, phosphorus, and potassium, but it is usually collected and treated as wastewater, resulting in nutrient loss. Direct emission of the high-temperature exhaust gas generated during fermentation not only results in heat loss but also increases the load on subsequent deodorization equipment. Summary of the Invention

[0006] The present invention aims to at least partially solve the aforementioned technical problems. Therefore, the objective of the present invention is to provide a rapid fermentation system for organic fertilizer.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An organic fertilizer rapid fermentation system includes a closed fermentation tank, a spiral agitator, a multi-layer aeration device, a control unit, and an integrated circulation system. The fermentation tank has an inlet and an outlet. The spiral agitator is vertically arranged along the central axis of the fermentation tank to vertically lift and mix the material inside from bottom to top. The multi-layer aeration device is installed on the side wall of the fermentation tank and includes at least two layers of aeration nozzles arranged tangentially along the inner wall of the tank. These nozzles create a horizontal rotating airflow within the tank and work in conjunction with the spiral agitator to achieve a three-dimensional spiral fluidization of the material. The control unit is electrically connected to a sensor array for monitoring the temperature, oxygen content, and material moisture inside the tank, as well as related actuators. The integrated circulation system includes a leachate collection unit connected to the bottom of the fermentation tank, a recirculation pipeline, and an atomizing injection device for atomizing the leachate and mixing it into the aeration airflow.

[0008] Preferably, the spiral mixing device includes a central rotating shaft and a wide-bladed spiral belt surrounding the rotating shaft, the rotation direction of which is set to lift the bottom material upwards, forming a vertical material circulation from bottom to top.

[0009] Preferably, the tangential spray direction of each aeration nozzle in the multi-layer aeration device is the same, and they work together to form a strong, uniform horizontal rotating airflow in the fermenter.

[0010] Preferably, the sensor array also includes sensors for monitoring pH and ammonia concentration inside the tank, providing the control unit with more comprehensive fermentation status information.

[0011] Preferably, the control unit has a built-in dynamic control program based on a fermentation process model. This program uses a fuzzy control algorithm to adaptively adjust the fermentation process in stages (e.g., heating phase, high-temperature phase, and ripening phase) based on real-time values ​​and rates of change of parameters such as temperature, oxygen content, and humidity collected by the sensor array. It can predict fermentation trends and adjust the rotation speed of the spiral agitator and the aeration frequency and volume of the multi-layer aeration device in advance.

[0012] Preferably, the control unit adopts an energy-saving operation mode of pulse aeration and intermittent stirring during high-temperature periods, which reduces the continuous running time of the fan and motor while ensuring sufficient oxygen supply and mixing.

[0013] Preferably, the atomizing injection device is a simple and reliable Venturi injector, or an ultrasonic atomizer that can produce finer droplets.

[0014] Preferably, the integrated circulation system also includes a gas-to-gas heat exchanger installed on the exhaust manifold of the fermenter. This heat exchanger uses the discharged high-temperature, high-humidity waste gas to preheat the fresh, cold air entering the multi-layer aeration device, thereby achieving heat energy recovery.

[0015] Preferably, the system also includes a biofilter or spray scrubbing tower type deodorization device connected downstream of the gas-to-gas heat exchanger for treating the cooled exhaust gas.

[0016] Preferably, the fermenter has a double-jacketed structure, and the heating device is installed in the jacket to provide uniform and stable auxiliary heating.

[0017] The beneficial effects of this invention are as follows: This invention achieves three-dimensional helical fluidization of materials through the synergistic effect of central spiral lifting and multi-layer tangential jets, completely eliminating dead zones in mixing and uneven aeration. This ensures full contact between aerobic microorganisms, oxygen, and materials, significantly improving fermentation speed and thoroughness. The dynamic fuzzy control strategy based on the process model achieves a leap from passive response to active prediction, enabling precise control of aeration and mixing, maximizing the utilization of microbial self-heating, and reducing ineffective energy consumption. The pulse and intermittent operation modes during high-temperature periods further reduce operating costs.

[0018] This invention also utilizes leachate atomization and re-spraying technology to return lost nutrients and moisture to the fermentation system in the most efficient aerosol form, achieving zero nutrient loss and uniform replenishment. Through waste gas heat recovery technology, heating energy consumption is significantly reduced. The entire system is highly sealed, and combined with efficient end-of-pipe deodorization, its environmental impact is minimal. Attached Figure Description

[0019] Figure 1 This is a functional structure diagram of an organic fertilizer rapid fermentation system provided in an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] It should be understood that, and also noted, in the embodiments, the functions / actions may appear in a different order than those shown in the figures. For example, depending on the functions / actions involved, they may actually be performed substantially concurrently, or sometimes the two figures shown consecutively may be performed in reverse order.

[0022] Figure 1This is a functional structural diagram of an organic fertilizer rapid fermentation system provided in an embodiment of the present invention. The core of the system is a sealed fermentation tank, which serves as the main fermentation site. The fermentation tank preferably employs a corrosion-resistant double-layer stainless steel jacket structure. Heat transfer oil can be circulated within the jacket, or an electric heating element can be installed as a heating device to provide auxiliary heating during the initial fermentation stage or in winter conditions. The tank has a feed inlet with a sealed cap at the top and a discharge outlet at the bottom for discharging the finished organic fertilizer.

[0023] Inside the fermenter, core components for efficient material mixing and aeration are installed. First, a spiral agitator is installed vertically along the central axis. This agitator consists of a central shaft driven by a variable frequency motor and a wide-bladed spiral band welded to the shaft. Its spiral direction is designed to continuously lift the material at the bottom of the tank upwards along the central axis, forming a continuous, bottom-up, vertically circulating flow. Second, on the inner wall of the fermenter, multiple sets of multi-layered tangential aeration nozzles are evenly distributed in three layers (upper, middle, and lower). Each layer of nozzles is installed tangentially to the tank wall, and all nozzles spray in the same direction to collaboratively generate a powerful horizontal rotational force. When the aeration airflow enters the tank from these nozzles, it drives the entire material layer to rotate horizontally. This synergistic effect of vertical lifting and horizontal rotation puts the organic material inside the tank in a vigorous yet orderly three-dimensional spiral fluidization state, ensuring that every material particle can fully contact oxygen, resulting in extremely high mass and heat transfer efficiency.

[0024] The core of this system is a control unit based on a PLC or industrial computer. For example... Figure 1 As shown, the control unit receives real-time data from a sensor array. This sensor array includes multiple temperature sensors, oxygen content sensors, humidity sensors, and optional pH and ammonia sensors distributed at different depths and locations within the material. Simultaneously, the control unit is also connected to all actuators, such as the motor driving the spiral agitator and the variable frequency fan controlling the aeration rate, providing precise control over them.

[0025] The core of the control unit is its built-in dynamic fuzzy control program. The entire fermentation process is divided into three main stages for intelligent regulation by this program: Heating and sterilization period: After the material is fed in, the system starts heating and moderate aeration to rapidly raise the material temperature to 65-75℃. The control program will focus on monitoring the heating rate (dT / dt). If the heating rate caused by microbial self-heating reaches the preset value, it will actively reduce or turn off the electric heating to prioritize the use of biological heat energy.

[0026] High-temperature primary fermentation stage: Temperature is maintained between 55-70℃. For example, when the control unit detects a "slowing rate of temperature increase" and "oxygen content below the threshold," fuzzy logic inference will determine that fermentation has entered a vigorous high-temperature stage. The system will predictively execute commands to "significantly increase aeration" and "appropriately increase stirring frequency." To further save energy, the program adopts an energy-saving mode of pulsed aeration and intermittent stirring during this stage.

[0027] Cooling and composting period: The material decomposition tends to stabilize, and the calorific value decreases. At this time, the control unit will significantly reduce the aeration rate and stirring frequency to create a stable micro-aerobic environment.

[0028] like Figure 1 As shown, this system also includes an integrated recycling system for the internal recycling of energy and nutrients.

[0029] The first step is the circulation of nutrients and water. The leachate collection unit includes a leachate collection port located at the conical bottom of the fermenter and a collection tank. The leachate collection port directs the leachate into the collection tank. After filtration, the leachate in the collection tank is pumped by a corrosion-resistant pump through a recirculation pipeline to an atomizing injection device (such as a Venturi injector).

[0030] Secondly, there is the circulation of energy and gas. Fresh air entering the system first flows through a gas-to-gas heat exchanger. Simultaneously, the high-temperature exhaust gas exiting from the top of the fermenter also enters this heat exchanger. The heat in the exhaust gas is transferred to the fresh air, achieving heat recovery. The preheated air then flows through an atomizing injection device, where a high-speed airflow generates negative pressure, drawing in the leachate and tearing it into tiny droplets, forming an aerosol. This hot air, carrying nutrient and moisture droplets, is finally injected into the fermenter through a multi-layer tangential aeration device.

[0031] Finally, there is environmental protection treatment. After heat recovery and cooling, the exhaust gas is guided to a deodorization device (such as a biofilter) for purification treatment, ultimately achieving compliance with emission standards.

[0032] This invention utilizes a synergistic agitation aeration structure, an intelligent dynamic fuzzy control strategy, and other methods... Figure 1 The integrated energy and nutrient closed-loop circulation system shown constitutes a complete, efficient, energy-saving, and environmentally friendly solution for rapid fermentation of organic fertilizer.

[0033] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A rapid fermentation system for organic fertilizer, characterized in that, include: A closed fermenter with an inlet and an outlet; A spiral stirring device, arranged vertically along the central axis inside the fermentation tank, is used to vertically lift and mix the materials inside the tank from bottom to top. The multi-layer aeration device is installed on the side wall of the fermenter. The multi-layer aeration device includes at least two layers of aeration nozzles arranged tangentially along the inner wall of the tank. It is used to form a horizontal rotating airflow in the tank and works in conjunction with the spiral stirring device to make the material in a three-dimensional spiral fluidization state. A control unit is electrically connected to a sensor array for monitoring the temperature, oxygen content and material moisture inside the tank, and to an actuator for driving the spiral agitator, multi-layer aeration device and heating device. And an integrated circulation system, the integrated circulation system comprising: a leachate collection unit connected to the bottom of the fermenter, a recirculation pipeline for returning the leachate, and an atomizing injection device installed on the recirculation pipeline for atomizing the leachate and mixing it into the aeration flow.

2. The system according to claim 1, characterized in that, The spiral mixing device includes a central rotating shaft and a wide-bladed spiral belt surrounding the rotating shaft, the spiral belt being rotated in a direction that lifts the material at the bottom upwards.

3. The system according to claim 1, characterized in that, The tangential spray direction of each aeration nozzle in the multi-layer aeration device is the same, so as to form a horizontal rotating airflow in a uniform direction in the fermenter.

4. The system according to claim 1, characterized in that, The sensor array also includes sensors for monitoring pH and ammonia concentration inside the tank.

5. The system according to claim 1, characterized in that, The control unit has a built-in dynamic control program based on a fermentation process model. The program uses a fuzzy control algorithm to adaptively adjust the speed of the spiral stirring device and the aeration frequency and volume of the multi-layer aeration device in stages, based on the parameters and their rate of change collected by the sensor array.

6. The system according to claim 1 or 5, characterized in that, The control unit adopts an energy-saving operation mode of pulse aeration and intermittent stirring during high-temperature periods.

7. The system according to claim 1, characterized in that, The atomizing injection device is a Venturi injector or an ultrasonic atomizer.

8. The system according to claim 1, characterized in that, The integrated circulation system also includes a gas-to-gas heat exchanger installed on the exhaust manifold of the fermenter, which is used to preheat the fresh air entering the multi-layer aeration device using the discharged high-temperature waste gas.

9. The system according to claim 8, characterized in that, It also includes a biofilter or spray scrubbing tower deodorization device connected downstream of the gas-to-gas heat exchanger.

10. The system according to claim 1, characterized in that, The fermenter has a double-layer jacket structure, and the heating device is installed in the jacket.

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