Multifunctional aerobic fermentation device suitable for indoor composting

Abstract

The invention belongs to the technical field of fermentation, and discloses a multifunctional aerobic fermentation device suitable for indoor composting, the multifunctional aerobic fermentation device comprises a fermentation tank, the top of the fermentation tank is provided with a tank cover with a feed pipe, and the top of the tank cover is provided with a stirring assembly comprising a motor, a transmission shaft and stirring blades; the bottom of the fermentation tank is fixedly connected with supporting legs and a discharge pipe; the aeration assembly is arranged in the fermentation tank, and an observation window with a sampling port is mounted on the side wall of the fermentation tank. According to the technical scheme, through linkage control of a PLC, the aeration rate, stirring parameters and temperature are dynamically adjusted according to different stages such as a temperature rising period, a high-temperature period and a temperature falling period of fermentation, and by combining layered monitoring, a three-stage deodorization tower and a three-point sampling design, precise coordinated regulation and control of all links are achieved, and it is ensured that materials make full contact with oxygen and are in a suitable environment; the problems that an existing device is single in function and extensive in control are effectively solved, and the indoor composting efficiency and the product quality are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fermentation technology, and specifically relates to a multifunctional aerobic fermentation device suitable for indoor composting. BACKGROUND

[0002] With the promotion of organic agriculture and the increasing demand for waste resource utilization, the use of organic materials such as agricultural and forestry waste and kitchen garbage through aerobic composting to produce high-quality fertilizer has become an important part of circular economy. Indoor composting, which is not limited by weather conditions and can be produced on a large scale, has gradually become the mainstream. Its core relies on the precise control of temperature, oxygen, and material state in the aerobic fermentation tank.

[0003] The existing indoor aerobic fermentation device generally has the problems of single function and extensive control. On the one hand, the aeration system cannot adjust the aeration amount according to the oxygen consumption demand of the fermentation stage (such as the warming-up period, the high-temperature period, and the cooling-down period), leading to uneven oxygen supply in the pile, thus causing local anaerobic reaction, producing odor and reducing fertilizer efficiency; while excessive aeration wastes energy and accelerates water loss, prolonging the fermentation period. On the other hand, temperature control relies mainly on experience adjustment, lacks coordination with aeration, and is combined with problems such as uneven mixing of materials, inefficient odor treatment, etc., ultimately leading to insufficient composting degree and unstable quality of the fertilizer, making it difficult to meet the market demand for high-quality organic fertilizer.

[0004] Chinese patent CN116283379B discloses a small-scale horizontal intelligent aerobic composting device, which works cooperatively through the fermentation tank, hot water tank, gas supply unit and PLC control unit on the support, realizes automatic composting with the help of temperature sensor, gas mass flow meter, etc., and processes condensate water through the condensate water discharge unit. However, the device does not have a special deodorizing device, only collects part of the ammonia-containing condensate water through the condensate water discharge unit, which is difficult to completely treat various foul-smelling gases produced during fermentation, and is easy to cause odor pollution of the environment; and does not design a convenient three-point sampling structure, only has a sampling port beside the tail gas outlet, which cannot conveniently sample and detect the upper, middle and lower three layers of the pile, and is not conducive to accurately grasping the fermentation state of each layer.

[0005] Chinese patent CN222358256U discloses a biological fermentation and deodorization integrated device, which works cooperatively through the deodorization mechanism (including collection, fermentation and purification components) on the base, collects foul-smelling gases through the fan, mixes the materials in the fermentation pool through the paddle, purifies the gases through the spray head, and monitors the purification state through the detection mechanism to realize the treatment of foul-smelling gases. However, the device does not have a special aeration structure, and the fan is only used to introduce the collected foul-smelling gases into the treatment link, which is difficult to ensure the uniformity of oxygen supply in the fermentation pool, and may affect the microbial activity; and does not have a precise temperature control device, only indirectly affects the state of the fermentation pool through the ambient temperature, and cannot adjust the appropriate temperature according to the microbial demand.

[0006] In view of the above problems, it is necessary to design a multifunctional aerobic fermentation device integrating timing and quantitative aeration, precise temperature control, efficient deodorization, convenient three-point sampling, intelligent stirring and PLC linkage control function, to form a synergistic working mechanism to improve the efficiency and product quality of indoor composting. SUMMARY

[0007] The purpose of the present application is to provide a multifunctional aerobic fermentation device suitable for indoor composting, which can integrate timing and quantitative aeration, precise temperature control, efficient deodorization, convenient three-point sampling, intelligent stirring and PLC linkage control function, to improve the efficiency and product quality of indoor composting.

[0008] The technical solutions adopted by the present application are as follows:

[0009] A multifunctional aerobic fermentation device suitable for indoor composting, comprising a fermentation tank, a tank cover is assembled on the top of the fermentation tank, a feed pipe is fixedly connected to the side wall of the tank cover, and a stirring assembly is arranged on the top of the tank cover.

[0010] A leg is fixedly connected to the bottom of the fermentation tank, and a discharge pipe is fixedly connected to the bottom of the fermentation tank.

[0011] It also comprises an aeration assembly arranged inside the fermentation tank.

[0012] Further, the stirring assembly comprises a bracket fixedly connected to the top of the tank cover, a motor is installed on the bracket, a transmission shaft is fixedly connected to the output end of the motor, the transmission shaft extends into the inner cavity of the fermentation tank, and stirring blades are fixedly connected to the side wall of the transmission shaft in the inner cavity of the fermentation tank.

[0013] Further, the aeration assembly comprises a hollow plate fixedly connected to the bottom end of the transmission shaft, a plurality of gas outlets are formed in the bottom surface of the hollow plate, a sleeve is rotatably connected to the upper side of the transmission shaft on the side wall of the transmission shaft, an airflow channel is formed in the bottom end surface of the transmission shaft, and the airflow channel is in communication with the inner cavity of the sleeve.

[0014] Further, an air inlet pipe is fixedly connected to the side wall of the sleeve, the air inlet pipe is in communication with the airflow channel, the other end of the air inlet pipe is connected to an air compressor, and a flow valve is installed on the side wall of the air inlet pipe.

[0015] Further, two sealing rings are fixedly connected to the inner wall of the sleeve, and the sealing rings abut against the side wall of the transmission shaft.

[0016] Further, an observation window is installed on the side wall of the fermentation tank. The observation window is provided with a detachable sampling port, and cooperates with the feed pipe and the discharge pipe to realize three-layer material sampling.

[0017] A fermentation control system of a multifunctional aerobic fermentation device suitable for indoor composting, comprising a total control panel, a material control system, a deodorization tower, and a monitoring system.

[0018] The total control panel comprises a power control circuit, a heating control circuit, a stirring control circuit, an aeration control circuit, and a deodorization tower control module, and is electrically connected with the power control circuit, the heating control circuit, the stirring control circuit, the aeration control circuit, and the deodorization tower control module.

[0019] The power control circuit is used for controlling the power on-off of the whole system.

[0020] The heating control circuit is used for controlling the switching of manual or automatic heating modes.

[0021] The stirring control circuit is used for controlling the forward and reverse rotation of the motor.

[0022] The aeration control circuit is used for controlling the aeration time and the aeration interval time.

[0023] The deodorization tower control module is used for detecting the NH3, H2S, and VOCs concentrations of the gas outlet, the pressure difference of the activated carbon layer, and controlling the start-stop and opening degree of the electric butterfly valve, and setting the alarm threshold.

[0024] The material control system is composed of a temperature sensor, a pH sensor, a moisture content sensor, an electric conductivity sensor, a jacket circulating water system, a PLC controller, and a material control circuit.

[0025] The temperature sensor, the pH sensor, the moisture content sensor, and the electric conductivity sensor are respectively installed at the upper, middle, and lower positions of the fermentation tank, for collecting the temperature, pH value, moisture content, and electric conductivity data of the materials at each layer in real time, and synchronously transmitting the data to the total control panel.

[0026] If the temperature in the fermentation tank is lower than the set value, the material control system triggers the jacket circulating water system to start circulating hot water, for maintaining the stable temperature of the materials.

[0027] In the automatic mode, the heating control circuit controls the temperature by dynamically adjusting the temperature according to the feedback of the collected data parameters, for controlling the temperature, humidity, and acidity and alkalinity of the materials in the fermentation state to be within the appropriate range.

[0028] The deodorization tower is installed at the side of the fermentation tank, connected with the gas outlet at the top of the tank cover through a corrosion-resistant pipeline, and an electric butterfly valve linked with the PLC controller is installed on the corrosion-resistant pipeline.

[0029] The monitoring system and the PLC controller form a man-machine interface for data acquisition, automatic control, alarm and interaction.

[0030] The components of the deodorization tower include:

[0031] Tower body fixing support (three or four leg supports, 0.2 m from the ground at the bottom);

[0032] Air inlet pipeline interface (located on the side of the lower tower body, 0.3 m from the ground, an electric butterfly valve is installed at the interface and the opening degree is controlled in linkage with the PLC);

[0033] Sewage outlet pipeline (located at the bottom of the side of the lower tower body, 0.2 m from the ground, used for discharging sewage and impurities during periodic backwashing of the primary filter layer);

[0034] Primary filter layer support net (1 mm aperture 304 stainless steel wire mesh, fixed to the lower tower body around 0.45 m from the ground by a clamping groove, thickness 0.02 m);

[0035] Lower part of the tower body shell (wraps the primary filter layer, welded and fixed to the ground support at the bottom, 0.2 to 0.5 m from the ground);

[0036] Chemical adsorption layer drawer frame (0.6 to 1.0 m from the ground, 0.5 m long x 0.4 m wide x 0.4 m high, 304 stainless steel drawer type structure, the bottom is a 40 mesh stainless steel screen, filled with modified zeolite and activated carbon);

[0037] Middle part of the tower body shell (wraps the chemical adsorption layer, sealed connection with the maintenance door on the side, 0.5 to 1.2 m from the ground);

[0038] Quick-release maintenance door (located on the side of the middle tower body, 0.55 to 1.05 m from the ground, completely covers the chemical adsorption layer drawer frame, can be pulled out without obstacles after opening to replace the filter material);

[0039] Upper part of the tower body shell (1.2 to 1.7 m from the ground, wraps the deep activated carbon layer, sealed connection with the maintenance opening at the top);

[0040] Deep activated carbon layer frame (1.25 to 1.55 m from the ground, diameter 0.55 m, height 0.3 m, detachable PP plastic frame, 2 symmetric handles are provided at the top, the gap between the frame and the inner wall of the tower body is 5 mm, facilitating vertical upward removal);

[0041] Pressure sensor interface (1.6 m from the ground, located on the side of the tower body, 0.1 m below the gas outlet, staggered with the maintenance opening);

[0042] Gas sensor mounting support (1.65 m from the ground, fixed to the inside of the gas outlet (horizontal pipeline), the sensor probe faces the inside of the tower body);

[0043] Outlet pipe (1.7 m from the ground, transversely from the side of the tower body (0.1 m from the top));

[0044] Top quick-release maintenance opening (1.7 to 1.8 m from the ground, diameter 0.65 m, slightly larger than the diameter of the tower body, cover thickness 0.03 m, fixed by 4 buckles, after opening, the top of the deep activated carbon layer can be completely exposed, facilitating the removal of the frame as a whole).

[0045] The technical effects achieved by the present application are:

[0046] The multifunctional aerobic fermentation device suitable for indoor composting can adjust the aeration amount in a timed and quantitative manner according to the fermentation stage, realize precise collaborative control of temperature and aeration, purify waste gas through the high-efficiency deodorization system, and take three samples (top feed inlet, middle observation window, and bottom discharge port) through the middle transparent observation window, intuitively observe the composting state of the middle of the material and obtain the sample data of the upper, middle, and lower three layers, solve the pain points of unknown state in the middle of the existing device, missing of layered data, and incomplete deodorization, and at the same time, ensure uniform mixing of the material through efficient structural design, solve the problems of anaerobic reaction caused by uneven oxygen supply of the pile, long fermentation period, and insufficient composting degree of the fertilizer, thereby improving the indoor composting efficiency, product quality, and production environment safety. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is a schematic diagram of the overall structure of the present application;

[0048] Figure 2 is a schematic diagram of the internal structure of the fermentation tank of the present application;

[0049] Figure 3 is a schematic diagram of the cross-sectional structure of the fermentation tank of the present application;

[0050] Figure 4 is an enlarged view of A in the present application; Figure 3

[0051] Figure 5 is an enlarged view of B in the present application; Figure 3

[0052] Figure 6 is a system block diagram of the present application.

[0053] In the drawings, the component list represented by each reference numeral is as follows:

[0054] 1, fermentation tank; 2, tank cover; 3, feed pipe; 4, motor; 5, transmission shaft; 6, stirring blade; 7, hollow plate; 8, air outlet; 9, sleeve; 10, air flow channel; 11, air inlet pipe; 12, air compressor; 13, sealing ring; 14, observation window; 15, discharge pipe. DETAILED DESCRIPTION​​

[0055] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0056] Example 1:

[0057] like Figures 1-5 As shown, a multifunctional aerobic fermentation device suitable for indoor composting includes a fermentation tank 1, a tank cover 2 is fitted on the top of the fermentation tank 1, a feed pipe 3 is fixedly connected to the side wall of the tank cover 2, and a stirring assembly is provided on the top of the tank cover 2; an observation window 14 is installed on the side wall of the fermentation tank 1.

[0058] The fermentation tank 1 is a sealed cylindrical structure with an inner and outer tank jacket. The inner tank has a diameter of 1.8 meters and a height of 3 meters, serving as a material-bearing cavity. It features a feed inlet at the top, a discharge outlet at the bottom, and a transparent observation window 14 (0.3-0.5 meters in diameter) in the middle of the side wall. This window is used to observe the degree of material decomposition and to take samples from the middle layer, enabling simultaneous sampling from the top, middle, and bottom layers of the fermentation pile, facilitating the detection of fermentation uniformity. A 50-100mm jacket space is formed between the inner and outer tanks. A water inlet pipe is located at the bottom of the jacket, and a water outlet pipe at the top, allowing for the introduction of circulating water and enabling a water bath heating function.

[0059] The bottom of the fermentation tank 1 is fixedly connected with support legs, and the bottom of the fermentation tank 1 is fixedly connected with a discharge pipe 15. The discharge pipe 15 can be a curved pipe or a straight pipe. For example, if the material inside the fermentation tank 1 is solid, a straight pipe can be used to facilitate its discharge and prevent blockage. If the material inside the fermentation tank 1 is liquid, a curved pipe can be used to reduce the distribution space of the pipe and increase the convenience of discharge.

[0060] It also includes an aeration assembly installed inside fermenter 1.

[0061] The stirring assembly includes a bracket fixedly connected to the top of the tank cover 2, a motor 4 mounted on the bracket, a drive shaft 5 fixedly connected to the output end of the motor 4, the drive shaft 5 extending into the inner cavity of the fermentation tank 1, and stirring blades 6 fixedly connected to the side wall of the drive shaft 5 within the inner cavity of the fermentation tank 1.

[0062] Among them, the stirring blade 6 can be an anchor frame stirring blade, a spiral ribbon stirring blade, or other types of stirring blades, to promote the mixing of materials and improve the fermentation rate. The following explanation uses the anchor frame stirring blade as an example:

[0063] Motor 4 is a three-phase asynchronous motor that drives a vertical stirring shaft via a reducer. Anchor-frame stirring blades are mounted on the shaft (the frame height is adapted to the material height inside fermenter 1, with a frame width of 100-150mm and a blade thickness of 8-10mm). The distance between the blades and the inner wall of fermenter 1 is 50-100mm to prevent scraping. Motor 4 is controlled by the main control panel and supports forward and reverse rotation modes. The anchor-frame structure creates omnidirectional agitation of the material inside the tank, ensuring uniform radial and axial mixing and promoting thorough gas-material contact and fermentation reaction.

[0064] The aeration assembly includes a hollow plate 7 fixedly connected to the bottom end of the drive shaft 5. Several air outlet holes 8 are opened on the bottom surface of the hollow plate 7. A sleeve 9 is rotatably connected to the side wall of the drive shaft 5 on the upper side of the tank cover 2. An airflow channel 10 is opened on the bottom end face of the drive shaft 5, and the airflow channel 10 communicates with the inner cavity of the sleeve 9.

[0065] The number of hollow plates 7 can be limited according to requirements. Hollow plates 7 can be set at the upper, middle and lower positions on the side wall of the drive shaft 5 to achieve sufficient aeration during the material accumulation and fermentation process, and avoid problems such as insufficient fermentation caused by local aeration.

[0066] In addition, another structural form of the aeration component is added: the air compressor 12 is a vortex air pump (such as the XGB-15 type), which is connected to the fermenter 1 through a high-pressure PVC air supply pipe to provide aeration power.

[0067] Pipeline control: Multi-stage air sterilization filters (filtering water vapor, suspended solids, and bacteria) and glass rotor flow meters (range 0.1-5m) are installed sequentially on the pipeline. 3 / h (the scale displays the ventilation rate) and air valves. Quantitative aeration can be achieved by observing the height of the valve ball or by electrically adjusting the valve opening.

[0068] An air inlet pipe 11 is fixedly connected to the side wall of the sleeve 9. The air inlet pipe 11 is connected to the airflow channel 10. An air compressor 12 is connected to the other end of the air inlet pipe 11. A flow valve is installed on the side wall of the air inlet pipe 11.

[0069] Two sealing rings 13 are fixedly connected to the inner wall of the sleeve 9, and the sealing rings 13 abut against the side wall of the drive shaft 5.

[0070] Example 2:

[0071] like Figure 6 As shown, a fermentation control system for a multifunctional aerobic fermentation device suitable for indoor composting includes a main control panel, a material control system, a deodorization tower, and a monitoring system. The monitoring system and the PLC controller form a human-machine interface for data acquisition, automatic control, alarm, and interaction.

[0072] The main control panel includes a power control circuit, a heating control circuit, a stirring control circuit, an aeration control circuit, and a deodorization tower control module. The main control panel is electrically connected to the power control circuit, heating control circuit, stirring control circuit, aeration control circuit, and deodorization tower control module.

[0073] The power control circuit is used to control the power supply to and from the entire system.

[0074] The heating control circuit is used to control the switching between manual and automatic heating modes; and is connected to the heating system of fermenter 1. It is equipped with an instrument panel to display the current temperature (which is collected and transmitted in real time by the temperature sensor inside fermenter 1) and the set temperature.

[0075] The stirring control circuit is used to control the forward and reverse rotation of motor 4;

[0076] The aeration control circuit controls the aeration time and aeration interval. The air compressor 12 is connected to the fermenter 1 through the air inlet pipe 11. The air flow rate is controlled by observing the scale line corresponding to the height of the small ball on the flow valve, thus achieving quantitative aeration. The air compressor 12 is controlled by the aeration control circuit on the main control panel and operates according to the set aeration time and interval.

[0077] Control logic: The air compressor 12 is driven by the aeration control circuit of the main control panel. It starts and stops according to the set aeration time (e.g., 5 minutes / time) and interval (e.g., 45 minutes). The air flow rate can be adjusted by the panel knob or electric valve.

[0078] The deodorization tower control module is used to detect the concentrations of NH3, H2S, and VOCs at the outlet, as well as the pressure difference of the activated carbon layer. It also controls the start, stop, and opening degree of the electric butterfly valve and sets alarm thresholds. Historical data can also be viewed, and there are waste indicator lights (green: normal operation (all indicators meet the standards); yellow: pressure difference warning (filter media needs cleaning); red: pollution exceeds the standard (automatic shutdown, filter media / activated carbon needs to be replaced)).

[0079] The material control system consists of a temperature sensor, a pH sensor, a moisture content sensor, a conductivity sensor, a jacketed circulating water system, a PLC controller, and a material control circuit.

[0080] Temperature sensors, pH sensors, moisture content sensors, and conductivity sensors are installed at the top, middle, and bottom of fermenter 1, respectively, to collect real-time data on the temperature, pH value, moisture content, and conductivity of materials in each layer and transmit the data synchronously to the main control panel.

[0081] If the temperature inside fermenter 1 is lower than the set value, the material control system triggers the jacket circulating water system to start circulating hot water to maintain a stable material temperature.

[0082] In automatic mode, the heating control circuit uses the PLC controller to dynamically adjust the temperature based on the collected data parameters, thereby controlling the temperature, humidity, and acidity / alkalinity of the material during fermentation to remain within a suitable range.

[0083] When the temperature is lower than the set value (e.g., 55℃), the monitoring system triggers the jacket water inlet pipe to start circulating hot water, which maintains the material temperature stability by uniformly heating the inner tank. At the same time, the system can combine the changing trends of parameters such as pH value and moisture content of each layer to provide a reference for adjusting the heating strategy.

[0084] The deodorization tower is installed on the side of fermentation tank 1. The tower body is 1.8 meters high and 0.6 meters in diameter. It is connected to the exhaust port on the top of tank cover 2 through a corrosion-resistant pipe. An electric butterfly valve linked to the PLC controller is installed on the corrosion-resistant pipe. The deodorization tower is installed from bottom to top as follows: primary filter layer (bottom of tower body, 0.3 meters high), chemical adsorption layer (middle of tower body, 0.7 meters high), and deep activated carbon layer (upper part of tower body, 0.6 meters high). Pressure sensor, NH3, H2S and VOCs sensor are installed at the air outlet at the top of the deodorization tower.

[0085] The primary filter layer uses stainless steel wire mesh (1mm aperture) to intercept dust and large particulate impurities ≥1mm, protecting the upper filter material, extending the replacement cycle of the chemical adsorption layer, and is equipped with a DN25 drain outlet at the bottom (manual valve for periodic backflushing).

[0086] The chemical adsorption layer uses a drawer-type stainless steel frame, with openings on all four sides. The filter media is supported by a 304 stainless steel mesh at the bottom and filled with modified zeolite and activated carbon particles (volume ratio 1:1). It removes NH3 and H2S through acid-base neutralization reaction, while adsorbing some VOCs.

[0087] The deep activated carbon layer uses a detachable plastic frame with built-in honeycomb activated carbon blocks to adsorb residual VOCs and odor molecules; a stainless steel perforated plate is installed at the bottom (to ensure uniform passage of exhaust gas), and a pressure sensor is installed at the top.

[0088] The NH3, H2S, and VOCs sensors installed inside the top air outlet transmit signals to the PLC controller via a 4-20mA analog module. The concentration values ​​(unit: mg / m³) are displayed in real time on the HMI touchscreen control panel. 3 The algorithm integrates alarm logic and valve linkage program, and plots a 24-hour trend curve.

[0089] The primary filtration layer and the chemisorption layer, as well as the chemisorption layer and the deep activated carbon layer, are connected by flanges with sealing rings (flange thickness 10mm, material 304 stainless steel) to ensure independent disassembly and sealing of each layer. A quick-release inspection door is located on the side of the tower body, in the middle of the chemisorption layer, for easy replacement of filter media; a circular inspection port is located on the top for inspection of the activated carbon layer and sensors.

[0090] In addition, the automatic control in the monitoring system is as follows: Based on preset fermentation process parameters, the heating device, air compressor 12, and motor 4 are adjusted for rotation and start / stop via relays and frequency converters. When motor 4 starts, stirring stops for 5 minutes. The PLC controller automatically stores sensor data (every 5 minutes apart) and supports historical data retrieval (traceable up to 30 days), facilitating analysis of the deodorization tower's operating efficiency and filter media replacement cycle.

[0091] Alarms and Interaction: Audible and visual alarms are triggered in case of abnormal temperature or equipment malfunction. Operators can modify parameters and set pollutant alarm thresholds via the touchscreen (default: NH3 = 2.8 mg / m³). 3 H2S = 0.25 mg / m³ 3 VOCs = 40 mg / m³ 3 ), View historical data or manually intervene in the operation status. When the pressure difference of the activated carbon layer > 500Pa, the yellow indicator light on the deodorization tower control module of the main control panel will light up, indicating that the filter media needs cleaning. When the NH3 at the outlet > 2.8mg / m³ 3 Or H2S > 0.25 mg / m³ 3 Or VOCs > 40 mg / m³ 3 When the time is right, the red indicator light will illuminate, the buzzer will sound an alarm, and the intake electric butterfly valve will automatically close to prevent the emission of substandard exhaust gases.

[0092] Example 3:

[0093] Based on Examples 1-2, this example discloses a fermentation method:

[0094] S1: Material Pretreatment and Feeding: When processing compost materials (such as straw and chicken manure), the materials are first cleaned, crushed, and air-dried. Then, the material mass ratio is adjusted, the feed inlet at the top of the fermentation tank is opened, and the materials are fed into the inner tank at a uniform speed. Composting agents are added in layers, and water is added appropriately to control the initial C / N ratio of the compost pile to be 25:1–30:1, with a moisture content of 60%–65%. When the volume of the added material reaches 70% of the inner tank's volume, the feed inlet is closed and the sealing valve is tightened.

[0095] S2: Fermentation Heating Period (Days 1-2): Switch to "Automatic Heating" mode on the main control panel, set the initial temperature of the jacketed circulating water to 40℃, and the PLC controller drives the tank heating. The upper / middle / lower temperature sensors in the inner tank provide real-time temperature feedback. When the material temperature reaches 45℃, the electric heating automatically stops, relying on the metabolic heat of microorganisms for natural heating (this depends on the heat released by the decomposition of easily degradable organic matter by thermophilic microorganisms). Simultaneously, turn on the air pump and operate it according to the set "aeration for 5 minutes / interval for 45 minutes" mode, adjusting the aeration rate to 2.7m³ / h using a glass rotor flow meter. 3 / h (Aeration rate at each stage is based on a 70% fill rate of the fermenter (material volume 5.34m³) 3 This conversion means that the aeration rate is 0.5 m³ / h per cubic meter of fermentation material. 3 (Air supply), the stirring motor is started once every 12 hours, rotating in both directions for 5 minutes each, at a speed of 35 r / min. The spiral blades turn the material to promote uniform heating and oxygen supply, ensuring the activity of microorganisms.

[0096] S3: High-Temperature Fermentation Period (Days 3-9): When any layer of temperature sensors detects a temperature ≥55℃, it indicates that the compost pile is entering the high-temperature fermentation stage. The jacket circulating water temperature is dynamically adjusted to 55-65℃ via PLC to ensure optimal activity of thermophilic bacteria; the aeration rate automatically increases by 0.3m³ for every 2℃ increase in temperature. 3 / h (maximum not exceeding 4.2m) 3 The system operates in a "5-minute aeration / 45-minute interval" mode, precisely regulated by an electric valve linked to the PLC. The stirring frequency is set to once a day, with each rotation being 10 minutes forward and 10 minutes reverse, at a speed of 45 rpm, to maintain oxygen supply and material mixing, preventing localized oxygen deficiency or overheating. The blades are spaced 80 mm from the tank wall to prevent scraping and ensure even material agitation.

[0097] S4: Cooling and composting period (day 10 to end): Stop heating when the material temperature naturally drops below 45℃, and adjust the aeration rate to 1.6m³. 3 / h, the aeration interval is extended to 60 minutes each time, while the aeration time remains 5 minutes; the stirring frequency is adjusted to once every two days, with each forward and reverse rotation running for 3 minutes, at a speed of 30 r / min. The stirring frequency and time are reduced to decrease energy consumption, while promoting moisture evaporation and uniform material maturation, avoiding excessive turning that could damage the maturation structure.

[0098] S5: Three-point sampling system: Starting from day one, the pile is sampled and stored daily through a three-point sampling system to observe changes in the appearance of the material. The water content and other parameters on the control panel are used to determine when to add water. To accurately determine the fermentation stage and adjust the composting parameters accordingly, samples are taken on days 1, 3, 6, and 10 of fermentation, and every 7 days thereafter. The humus content, seed germination index, and carbon-nitrogen ratio in the samples are tested.

[0099] S6: Intelligent Deodorization Tower: Fermentation waste gas enters the intelligent deodorization tower through the top exhaust port, passing sequentially through a primary filtration layer to intercept dust and large particulate impurities; a chemical adsorption layer (modified zeolite + activated carbon) removes 60%-70% of NH3 and H2S, while also adsorbing some VOCs; a deep activated carbon layer adsorbs the remaining VOCs and odor molecules. If the data from the pressure, NH3, H2S, and VOCs sensors exceed the set thresholds, corresponding actions must be taken according to the indicator lights.

[0100] S7: Composting Determination and Discharge: The compost pile temperature remains stable within ±5℃ of the ambient temperature for 3-5 consecutive days without significant rise; the compost product is dark brown, blackish-brown, or dark brown in color, with a loose and fine texture, no obvious undecomposed raw materials, and no pungent odors such as foul smell, ammonia smell, or sour smell, emitting a natural earthy smell or a slight composting odor; at the same time, the product testing meets the following requirements: C / N ratio ≤ 15:1, seed germination index (GI) ≥ 80%, and humus content significantly increased compared to the initial stage and tending to stabilize in the later stage. After meeting the above conditions, open the bottom discharge port and start motor 4 to assist in material discharge. The composted fertilizer is then screened through a vibrating sieve and packaged for storage or applied directly.

[0101] To verify the composting effect of this invention, a control experiment was conducted to compare the fermentation performance of the device of this invention (T1 group) with that of open-air composting (CK group). The experimental setup was as follows:

[0102] Both groups used the same initial materials: straw and chicken manure mixed at a mass ratio of 3:1, with an initial C / N ratio of 25:1, a moisture content of 62%, and a total material volume of 5.34 m³. 3 (Corresponding to a 70% fill rate in the fermentation tank);

[0103] Group T1 uses the multifunctional aerobic fermentation device described in this invention (claims 1-6), operates according to the staged fermentation method (claim 10), and is monitored and controlled in real time by sensors (claims 7-9);

[0104] Group CK is open-air compost (accumulated in a natural environment, with regular manual turning).

[0105] The monitoring indicators included temperature, pH, electrical conductivity, moisture content, C / N ratio, seed germination index (GI), and organic matter content. The sampling time points were days 1, 3, 6, 10, 17, 24, and 31. The results are as follows.

[0106] Table 1. Comparison of full-cycle fermentation indicators between aerobic fermentation equipment and open-air composting.

[0107]

[0108]

[0109] As shown in Table 1, this invention achieves a significant improvement in composting efficiency and product quality through the synergy of innovative device structure and a staged fermentation method. A detailed analysis follows:

[0110] I. Linkage Design of Mixing and Aeration Components: The mixing and aeration components of the device of this invention work together. When the mixing blades rotate forward and backward to turn the material, the hollow plate rotates synchronously with the drive shaft, so that the airflow is evenly diffused to the pile through the air outlet. On the 3rd day, the temperature of group T1 reached 57.6℃, which is 8.8℃ higher than that of group CK, thus solving the problem of local anaerobicness caused by uneven oxygen supply in open composting.

[0111] II. Precise Control of Layered Monitoring and Temperature Control System: Temperature, pH, and moisture content sensors installed at the top, middle, and bottom of the fermenter, combined with the jacketed circulating water system, achieve dynamic temperature control: during the heating phase, the material is rapidly heated to 45°C; during the high-temperature phase, the temperature is maintained at 55-65°C; and during the cooling phase, the temperature naturally drops. In contrast, the CK group, lacking a temperature control device, experiences large temperature fluctuations and a short high-temperature phase, resulting in a slow decrease in the C / N ratio.

[0112] III. The method of this invention dynamically adjusts the aeration rate according to the "heating period - high temperature period - cooling period": 2.7m during the heating period. 3 / h ensures the activity of thermophilic bacteria; during the high-temperature period, the aeration is increased as the temperature rises to meet the oxygen consumption requirements of thermophilic bacteria; during the cooling period, the aeration is reduced to 1.6m. 3 / h reduces energy consumption. This precise aeration method enabled the T1 group to reach the composting standard earlier than the CK group.

[0113] IV. Optimized design of stirring frequency: The method of stirring every 12 hours during the heating period, daily during the high-temperature period, and every two days during the cooling period avoids moisture loss caused by excessive stirring, while ensuring uniform mixing of materials. In contrast, the CK group's manual fixed daily turning frequency resulted in delayed decomposition of the bottom material, with a GI value of 78.83% on day 31, while the T1 group reached 95.36%.

[0114] 5. By taking samples at three points daily through the observation window, the water replenishment and aeration parameters can be adjusted in real time; the three-stage deodorization tower simultaneously treats the exhaust gas, preventing the spread of odors generated by the high temperature and humidity in the T1 group. This "device-method" synergistic mechanism ultimately shortens the composting cycle of the T1 group by more than 30% and increases the product GI value by more than 15%, solving the pain points of single function and extensive control in existing technologies.

[0115] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operation control systems not specifically described or explained in this invention are implemented according to conventional methods in the art unless otherwise specified or limited.

Claims

1. A multifunctional aerobic fermentation device suitable for indoor composting, comprising a fermentation tank (1), wherein a tank cover (2) is fitted on the top of the fermentation tank (1), and a feed pipe (3) is fixedly connected to the side wall of the tank cover (2), characterized in that: A stirring assembly is provided on the top of the can lid (2); The fermentation tank (1) is fixedly connected to the bottom with support legs, and the fermentation tank (1) is fixedly connected to the bottom with a discharge pipe (15); It also includes an aeration assembly installed inside the fermenter (1).

2. The multifunctional aerobic fermentation device suitable for indoor composting according to claim 1, characterized in that: The stirring assembly includes a bracket fixedly connected to the top of the tank cover (2), a motor (4) is mounted on the bracket, a drive shaft (5) is fixedly connected to the output end of the motor (4), the drive shaft (5) extends into the inner cavity of the fermentation tank (1), and a stirring blade (6) is fixedly connected to the side wall of the drive shaft (5) in the inner cavity of the fermentation tank (1).

3. The multifunctional aerobic fermentation device suitable for indoor composting according to claim 2, characterized in that: The aeration assembly includes a hollow plate (7) fixedly connected to the bottom end of the drive shaft (5). The bottom surface of the hollow plate (7) is provided with a plurality of air outlet holes (8). The side wall of the drive shaft (5) is rotatably connected to a sleeve (9) on the upper side of the tank cover (2). The bottom end face of the drive shaft (5) is provided with an airflow channel (10), which is connected to the inner cavity of the sleeve (9).

4. A multifunctional aerobic fermentation device suitable for indoor composting according to claim 3, characterized in that: An air inlet pipe (11) is fixedly connected to the side wall of the sleeve (9). The air inlet pipe (11) is connected to the airflow channel (10). An air compressor (12) is connected to the other end of the air inlet pipe (11). A flow valve is installed on the side wall of the air inlet pipe (11).

5. A multifunctional aerobic fermentation device suitable for indoor composting according to claim 4, characterized in that: Two sealing rings (13) are fixedly connected to the inner wall of the sleeve (9), and the sealing rings (13) abut against the side wall of the transmission shaft (5).

6. A multifunctional aerobic fermentation device suitable for indoor composting according to claim 1, characterized in that: The fermenter (1) is equipped with an observation window (14) on its side wall, and the observation window (14) is provided with a detachable sampling port.

7. A fermentation control system for a multifunctional aerobic fermentation device suitable for indoor composting, used to control the multifunctional aerobic fermentation device for indoor composting as described in any one of claims 1-6, characterized in that: Includes the main control panel, material control system, deodorization tower, and monitoring system; The main control panel includes a power control circuit, a heating control circuit, a stirring control circuit, an aeration control circuit, and a deodorization tower control module. The main control panel is electrically connected to the power control circuit, the heating control circuit, the stirring control circuit, the aeration control circuit, and the deodorization tower control module. The power control circuit is used to control the power supply on / off of the entire system. The heating control circuit is used to control the switching between manual and automatic heating modes; The stirring control circuit is used to control the forward and reverse rotation of the motor (4); The aeration control circuit is used to control the aeration time and the aeration interval time. The deodorization tower control module is used to detect the concentrations of NH3, H2S, and VOCs at the outlet, the pressure difference of the activated carbon layer, and to control the start, stop, and opening degree of the electric butterfly valve, and to set alarm thresholds.

8. The fermentation control system for a multifunctional aerobic fermentation device suitable for indoor composting according to claim 7, characterized in that: The material control system consists of a temperature sensor, a pH sensor, a moisture content sensor, a conductivity sensor, a jacketed circulating water system, a PLC controller, and a material control circuit. Temperature sensors, pH sensors, moisture content sensors, and conductivity sensors are installed at the top, middle, and bottom of the fermenter (1) to collect the temperature, pH value, moisture content, and conductivity data of each layer of material in real time and transmit them synchronously to the main control panel. If the temperature inside the fermenter (1) is lower than the set value, the material control system triggers the jacket circulating water system to start circulating hot water to maintain the material temperature. In automatic mode, the heating control circuit uses the PLC controller to dynamically adjust the temperature based on the collected data parameters, thereby controlling the temperature, humidity, and acidity / alkalinity of the material during fermentation to remain within a suitable range. The deodorization tower is installed on the side of the fermentation tank (1) and connected to the exhaust port on the top of the tank cover (2) through a corrosion-resistant pipe. An electric butterfly valve linked to the PLC controller is installed on the corrosion-resistant pipe. The deodorization tower is equipped with a primary filter layer, a chemical adsorption layer, and a deep activated carbon layer from bottom to top. A pressure sensor, NH3, H2S, and VOCs sensor are installed at the top of the deodorization tower.

9. The fermentation control system for a multifunctional aerobic fermentation device suitable for indoor composting according to claim 8, characterized in that: The monitoring system and the PLC controller form a human-machine interface for data acquisition, automatic control, alarm and interaction.

10. A fermentation method, characterized in that: The multifunctional aerobic fermentation device for indoor composting according to any one of claims 1 to 6 includes the following steps: Step 1, Pre-treatment of feed: After removing impurities and crushing the compost material, it is put into the fermentation tank. The initial C / N ratio is controlled at 25:1 to 30:1 and the moisture content is 60% to 65%. The tank is sealed when the material reaches 70% of its volume. Step 2, staged fermentation: During the warming period, control the temperature to 45℃ and the aeration rate to 2.7m³. 3 / h (Aeration rate at each stage is based on a 70% fill rate of the fermenter (material volume 5.34m³) 3 This conversion means that the aeration rate is 0.5 m³ / h per cubic meter of fermentation material. 3 (Air supply), aeration for 5 minutes / 45 minutes interval, stirring once every 12 hours, forward and reverse rotation for 5 minutes each, speed 35 r / min; during the high-temperature period, the temperature is 55-65℃, and for every 2℃ increase in temperature, the aeration volume increases by 0.3 m³ / min. 3 / h, not exceeding 4.2m 3 Aeration time: 5 minutes / h, 45-minute interval; stirring once daily, 10 minutes forward and 10 minutes reverse rotation, 45 rpm; heating stopped during cooling period; aeration volume: 1.6 m³ / h. 3 / h, aeration for 5 minutes / 60 minutes interval, stirring once every two days, forward and reverse rotation for 3 minutes each, speed 30r / min; Step 3, auxiliary treatment: Samples are taken at three points daily for testing. The exhaust gas is treated by a three-stage deodorization tower and discharged after meeting the standards.

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