Organic waste anaerobic fermentation equipment

Abstract

The utility model belongs to the technical field of biological fermentation, and particularly relates to organic waste anaerobic fermentation equipment which comprises a fermentation tank arranged on a base body, the fermentation tank is provided with a feeding end and a discharging end which are oppositely arranged, the feeding end is provided with a premix processing device, and the discharging end is provided with a discharging device; the stirring device is used for stirring materials in the fermentation tank, the stirring device comprises a main shaft and stirring blades arranged on the main shaft, the main shaft is eccentrically arranged relative to the fermentation tank, and the stirring blades are arranged on the main shaft. The distance between the stirring blades and the top wall of the fermentation tank is greater than the distance between the stirring blades and the bottom wall of the fermentation tank; the micro-aerobic device is communicated with the fermentation tank and is used for providing oxygen into the fermentation tank; and the modular heating device is arranged on the fermentation tank and is used for heating materials. Therefore, the problems of low fermentation efficiency, high energy consumption and high waste gas yield of fermentation equipment in the prior art are solved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of biological fermentation technology, and specifically relates to an organic waste anaerobic fermentation equipment. BACKGROUND

[0002] Due to the great difference in the composition of organic waste (such as kitchen waste, agricultural waste), it may contain high lignin, cellulose and other refractory substances, resulting in slow microbial decomposition. The imbalance of carbon-nitrogen ratio (C / N) (such as too high or too low) will affect the microbial activity and reduce the gas production efficiency. Anaerobic fermentation is divided into medium temperature (30-45 DEG C) and high temperature (50-60 DEG C) two kinds, if the temperature fluctuation or does not reach the standard, the microbial metabolic efficiency will decrease significantly. The accumulation of volatile fatty acid (VFA) in the fermentation process may lead to pH reduction, inhibiting the activity of methanogenic bacteria. In addition, insufficient mechanical stirring may lead to material layering or crust formation, and low mass transfer efficiency; excessive stirring may destroy the microbial community.

[0003] Anaerobic fermentation relies on the synergistic effect of hydrolytic bacteria, acid-producing bacteria and methanogenic bacteria, and if the activity of the bacteria in a certain link is insufficient (such as sulfide inhibiting methanogenic bacteria), the overall efficiency will be reduced. The hydraulic retention time (HRT) or solid retention time (SRT) is too short, and the organic matter is not fully degraded before being discharged. Maintaining constant temperature (especially high temperature fermentation) requires continuous energy consumption, and if the reactor has poor heat preservation performance or the heat recovery system has low efficiency, the energy consumption will increase significantly. The pretreatment steps such as crushing, sorting or desalting will increase the additional energy consumption, especially for complex waste (such as mixed garbage). When the anaerobic environment is destroyed, facultative bacteria will carry out aerobic metabolism, producing CO2 instead of methane, resulting in increased waste gas. Excessive activity of acid-producing bacteria will lead to accumulation of VFA and CO2, while methanogenic bacteria cannot be converted in time. The decomposition of sulfur-containing organic matter (such as protein) will produce H2S, and CO2 is a natural by-product of anaerobic fermentation, and if the desulfurization measures are insufficient, the waste gas treatment pressure will increase. The reactor or pipeline is not tightly sealed, which will lead to the escape of methane (CH4), not only reducing the energy recovery rate, but also increasing the greenhouse gas emissions.

[0004] In view of the problems of low fermentation efficiency, high energy consumption and high waste gas yield of the fermentation equipment in the prior art, a more reasonable technical scheme is urgently needed to optimize and improve the whole anaerobic fermentation system, so as to solve the current technical problems. UTILITY MODEL CONTENT

[0005] The utility model aims at providing an organic waste anaerobic fermentation equipment to solve the problems of low fermentation efficiency, high energy consumption and high waste gas yield of the fermentation equipment in the prior art.

[0006] In order to realize the above-mentioned purpose, the utility model provides an organic waste anaerobic fermentation equipment, which comprises:

[0007] A fermentation tank is arranged on the base body, and has a feeding end and a discharging end arranged oppositely, wherein the feeding end is provided with a premixing material processing device, and the discharging end is provided with a discharging device;

[0008] A stirring device is arranged for stirring the material in the fermentation tank, and comprises a main shaft and stirring blades arranged on the main shaft, wherein the main shaft is arranged eccentrically relative to the fermentation tank, so that the distance between the stirring blades and the top wall of the fermentation tank is greater than the distance between the stirring blades and the bottom wall of the fermentation tank.

[0009] A micro-oxygen device is connected to the fermentation tank and used for providing oxygen into the fermentation tank; and

[0010] A modular heating device is arranged on the fermentation tank and used for heating the material.

[0011] Optionally, the stirring device comprises:

[0012] A driving motor is used for providing driving force;

[0013] The main shaft is arranged in the fermentation tank and rotatably connected to the fermentation tank through the second bearing at both ends thereof; and

[0014] A plurality of stirring blades are arranged, each of which comprises a connecting rod and a material starting body, wherein the connecting rod is arranged spirally along the axial direction of the main shaft, and both ends of the connecting rod are fixedly connected to the main shaft and the material starting body respectively.

[0015] Optionally, along the rotating direction of the main shaft, the material starting body has opposite front and rear material contact surfaces, wherein the extension length of the rear material contact surface is greater than that of the front material contact surface.

[0016] Optionally, along the radial direction away from the main shaft, the opening size of the material starting body gradually increases.

[0017] Optionally, the distance between the stirring blades and the bottom wall of the fermentation tank is at least 1 meter, and the distance between the stirring blades and the top wall of the fermentation tank is at least 1.5 meters.

[0018] Optionally, the anaerobic fermentation equipment for organic waste further comprises a limiting device, which comprises a supporting frame and a third bearing, the supporting frame is fixedly arranged in the fermentation tank, the third bearing is coaxially arranged relative to the main shaft and connected to the supporting frame, and the main shaft is inserted into the inner ring of the third bearing.

[0019] Optionally, the inclination angle of the fermentation tank is 1‰-3‰ of the total length of the fermentation tank body.

[0020] Optionally, the micro-aerobic device is arranged in two groups and arranged at the feeding end of the fermentation tank, and the air nozzle of the micro-aerobic device is arranged at the lower region of the fermentation tank and spaced relative to the stirring blade.

[0021] Optionally, the discharging device comprises a third motor and a third spiral blade, wherein the third spiral blade is arranged in the fermentation tank, and one end of the spiral blade is connected to the fermentation tank through a third positioning shaft; the third motor is drivingly connected to the third positioning shaft; when the third motor rotates, the third positioning shaft drives the third spiral blade to rotate, so as to push the material out of the fermentation tank.

[0022] Optionally, the organic waste anaerobic fermentation equipment further comprises a detection device communicatively connected to the controller, wherein the detection device comprises one or more of a pressure sensor, a liquid level detector, a temperature sensor, and a torque sensor, wherein the pressure sensor is used to detect the current pressure information in the fermentation tank, the liquid level detector is used to detect the current liquid level height in the fermentation tank, the temperature sensor is used to detect the current temperature information in the fermentation tank, and the torque sensor is arranged on the main shaft and / or the stirring blade and is used to detect the current torque information.

[0023] The detection device further comprises one or more of a methane sensor, a pH sensor, a hydrogen sulfide sensor, and a CO2 / O2 concentration analyzer.

[0024] The working principle of the organic waste anaerobic fermentation equipment is as follows: in the pretreatment stage, the premixing device homogenizes and conditions (controls the dry matter content to be 20% to 40%) the raw materials and kills pathogenic bacteria; in the main fermentation stage, the eccentric stirring and modular heating device maintains an anaerobic environment and promotes the microbial chain reaction of hydrolysis-acid production-methane production; in the post-treatment stage, the discharging device stably discharges the residue to avoid disturbing the active sludge layer.

[0025] Based on the eccentric arrangement of the main shaft, the main shaft is offset from the center of the tank body to form an asymmetric flow field (large gap at the top and small gap at the bottom), so that the large bubbles at the top are broken (to enhance the gas-liquid mass transfer), and the strong shear force at the bottom can prevent sedimentation, and the precise injection of trace oxygen (DO < 0.1 mg / L) through the micro-aerobic device can stimulate the activity of facultative bacteria and accelerate hydrolysis.

[0026] During the fermentation process, the top large gap can avoid the scum layer to block the stirring shaft, while promoting biogas release; and the bottom small gap can make the high shear force prevent sand and stone deposition and reduce the wear rate. Through pulse oxygen supply, the hydrolysis efficiency is improved, and the anaerobic environment is not damaged. The modular heating device (such as a hot water jacket) is linked with stirring to improve temperature uniformity. Eccentric stirring increases the cellulose contact area, reduces the hydrolysis time; micro-oxygen stimulation increases the activity of methanogenic bacteria, and the CH4 proportion is improved. Temperature and stirring are cooperatively controlled, pH fluctuation is reduced, and it is beneficial to help fermentation. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0028] Figure 1 is the front view structural schematic diagram of the organic waste anaerobic fermentation equipment provided by the present application;

[0029] Figure 2 is the side view structural schematic diagram of the organic waste anaerobic fermentation equipment provided by the present application;

[0030] Figure 3 is the layout schematic diagram of the heating body in the modular heating device provided by the present application, wherein the density of the heating body gradually decreases along the direction from left to right;

[0031] Figure 4 is the perspective structural schematic diagram of the premixing material processing device for the fermentation tank provided by the present application;

[0032] Figure 5 is the structural schematic diagram of the stirring device in the organic waste anaerobic fermentation equipment in one embodiment provided by the present application;

[0033] Figure 6 is the structural schematic diagram of the stirring device in the organic waste anaerobic fermentation equipment in another embodiment provided by the present application;

[0034] Figure 7 is the structural schematic diagram of the stirring device in the organic waste anaerobic fermentation equipment in still another embodiment provided by the present application.

[0035] In the above figure: 1-modular heating device, 11-heating body, 2-premix processing device, 21-feeding box, 211-feeding processing area, 212-secondary processing area, 213-feeding processing area, 22-mixing mechanism, 221-first positioning shaft, 222-first spiral blade, 223-first motor, 23-transporting mechanism, 231-second motor, 232-second spiral blade, 24-ejecting mechanism, 25-steam mechanism, 26-weighing sensor, 27-camera, 3-fermentation tank, 4-discharging device, 5-stirring device, 51-main shaft, 52-stirring blade, 521-connecting rod, 522-lifting body, 5221-early contact material surface, 5222-late contact material surface, 6-micro-oxygen device. DETAILED DESCRIPTION

[0036] The utility model will be further described below in combination with the drawings and specific embodiments. It should be noted that the description of these embodiments is used to help understand the utility model, but does not constitute a limitation on the utility model. The specific structure and functional details disclosed in this paper are only used to describe the embodiments of the example of the utility model. However, the utility model can be embodied in many alternative forms, and should not be understood as limiting the utility model in the embodiments described herein.

[0037] According to the first aspect of the present disclosure, a modular heating device for a fermentation tank is provided, wherein, Figures 1 to 7 The specific implementation case of the modular heating device is shown.

[0038] Referring to Figures 1 to 7 As shown, the modular heating device 1 comprises: a hot water tank for storing liquid; a plurality of connecting pipes, each end of each connecting pipe being connected to the hot water tank through a pipeline, a first control valve and a first electromagnetic valve being provided on the pipeline, and the first control valve being located near one end of the connecting pipe; a plurality of heat collecting mechanisms corresponding to the connecting pipes, each heat collecting mechanism being connected to the connecting pipe and being used for heating the introduced liquid; a circulating pump connected to the pipeline to enable the water to circulate between the hot water tank and the heat collecting device; and a plurality of heating modules, each heating module being arranged along the axial direction of the fermentation tank 3; each heating module comprises a plurality of heating bodies 11 arranged along the circumferential direction of the fermentation tank 3, and the heating bodies 11 made of heat-conducting material are sequentially connected; wherein the top area of the fermentation tank 3 is not provided with a heating module; the flow channels of the hot water tank, the connecting pipes, the pipeline, the heat collecting mechanisms and the heating modules jointly form a circulating water circuit.

[0039] The modular heating device adopts a circulating hot water indirect heating method. A closed circulating water path is formed by a hot water tank, a joint collector, a heat collecting mechanism, a circulating pump and a heating module to achieve uniform and controllable heating of the fermentation tank 3. The core principle is as follows: the heat collecting mechanism (such as a solar collector, an electric heater or a waste heat recovery device) heats the liquid (water or heat conducting oil) and distributes it to each heating module through the joint collector. The circulating pump drives the hot water to flow in the circulating water path, and the heat is transferred to the organic waste in the fermentation tank 3 through the heating body 11 of the heat conducting material. Multiple heating modules are distributed along the axial direction of the fermentation tank 3 to avoid local overheating or uneven temperature. No heating module is arranged at the top of the fermentation tank 3 to reduce heat loss and prevent the top from being covered with a crust. The hot water flow of each joint collector is adjusted by the first control valve and the first electromagnetic valve to achieve precise temperature control in different areas.

[0040] The low-temperature liquid in the hot water tank is delivered to the heat collecting mechanism by the circulating pump, and after being heated, it flows into the joint collector. The electromagnetic valve controls the hot water into the designated heating module according to the temperature sensor signal. The hot water flows through the heat conducting body of the heating module, and the heat is conducted to the fermentation material through the tank wall, and the cooled liquid returns to the hot water tank, forming a closed loop circulation. If the temperature of a certain area is lower than the set value (such as the hydrolysis reaction zone), the opening degree of the electromagnetic valve corresponding to the joint collector is increased to increase the hot water flow. When the temperature at the top is too high, some valves can be closed to reduce the heat input.

[0041] Through the above technical effects, the circulating water path reduces heat loss, and the energy consumption is reduced by more than 30% compared with direct electric heating. The heat conducting material (such as stainless steel or copper) can improve the heat transfer efficiency of the heating body 11. Axial and circumferential segmented heating avoids "cold / hot zones", maximizes microbial activity. The top is not heated to reduce water evaporation and prevent the material from drying and crust formation, improving gas release. Automatic temperature control is achieved through valves and sensors, suitable for different fermentation stages (such as mesophilic / thermophilic fermentation). In this way, the fermentation process can be maintained at 35-55°C (mesophilic / thermophilic fermentation range), accelerating the hydrolysis and methanogenesis rate, and shortening the residence time. At the same time, precise temperature control avoids the sudden drop in pH caused by VFA accumulation, ensuring the activity of methanogens. In this way, this uniform heating method avoids the destruction of the local anaerobic environment, reduces the abnormal emission of CO2 and H2S. Temperature stability improves the metabolic efficiency of methanogens, and the CH4 content in biogas increases by 10%-20%. Compared with traditional steam heating, the comprehensive energy consumption of the circulating water path system can be effectively reduced. Through the closed loop circulation and zoned temperature control design, the problem of uneven heating and high energy consumption of traditional fermentation tanks 3 is solved, significantly improving the stability and energy conversion efficiency of anaerobic fermentation. Its technical advantages directly translate into higher biogas production, lower operating costs and less waste gas emissions, suitable for large-scale organic waste treatment scenarios.

[0042] In one embodiment provided in the present disclosure, referring to Figure 2As shown, the inner wall and the outer wall of the fermentation tank 3 are embedded with heating bodies 11, wherein the inner wall of the fermentation tank 3 has a circumference F1, and the heating bodies 11 have a length F2 in the circumferential direction of the inner wall of the fermentation tank 3, F2 = (0.25-0.5)F1, that is, the heating bodies 11 only cover part of the circumference (25%-50%) of the inner wall to form an intermittent heat conduction surface, so as to avoid the whole inner wall from being overheated and causing the material to adhere. The unheated area (low-heat area) allows the material to naturally settle and flow, thereby reducing the stirring energy consumption. The low-heat area of the inner wall reserves space for the operation of the mechanical scraper or cleaning device, thereby avoiding the difficulty in maintenance caused by the full circumferential coverage of the heating bodies 11.

[0043] The outer wall of the fermentation tank 3 has a circumference F3, and the heating bodies 11 have a length F4 in the circumferential direction of the outer wall of the fermentation tank 3, F4 = (0.8-0.9)F3. That is, the outer wall heating bodies 11 cover 80%-90% of the circumference, so as to compensate for the insufficient heating of the inner wall by the external main heating and maintain the overall temperature stability of the tank body. The outer wall reserves 10%-20% of the non-heated area (such as an access hole or a sensor installation position), which takes into account the functionality and thermal efficiency.

[0044] By the above technical solution, the direct heat contact area between the inner wall and the material can be reduced, and the risk of instantaneous heat shock of the microorganism (especially the protection of the methanogen) in the high-temperature area can be reduced. Through the radial heat diffusion of the heat-conducting material (such as stainless steel), the homogenization effect from point heat source to surface heat transfer is achieved. The outer wall as the main heating surface indirectly transfers heat through the heat conductivity of the tank body material (such as steel lining PE), thereby avoiding the local overheating of the inner wall. The unheated area (low-heat area) of the inner wall forms a temperature gradient with the heated area, so as to drive the natural convection (hot rises and cold falls) of the material and reduce the dependence on mechanical stirring. The high coverage rate of the outer wall ensures the continuous supply of heat during the convection process, thereby avoiding temperature stratification. The traditional full-circumferential heating is easy to cause the water in the material near the inner wall to evaporate too quickly, thereby forming a hard crust. The present design retains humidity in the low-heat area to reduce the risk of crust formation. Thus, through the cooperative heating of the inner and outer walls, the temperature field distribution of “external main heat and internal auxiliary” is achieved, so as to control the temperature difference of the material in the tank within ±1°C, thereby promoting the balanced activities of the microbial community.

[0045] It should be noted that, as shown in Figure 2 The areas of the inner wall and the outer wall where the heating bodies 11 are not arranged coincide, so as to form a low-heat area, thereby providing an escape channel for the gas bubbles (CH4 / CO2) and preventing the accumulation of gas to cause a scum layer. The stable temperature field avoids local acidification (VFA accumulation) and reduces the abnormal emission of H2S and CO2. The methanogen has higher activity in a mild heat environment, which helps to improve the CH4 concentration in the biogas.

[0046] In order to reduce heat loss, the modular heating device 1 further comprises a heat preservation module (not shown in the figure), which is detachably wrapped around the outer periphery of the fermentation tank 3. The detachable design facilitates the maintenance of the heating body 11, sensors or tank body, and avoids the maintenance difficulty of the traditional fixed heat preservation layer.

[0047] The heat preservation module isolates the outer wall of the fermentation tank 3 from the environment, inhibits convective and radiative heat loss, and reduces overall heat loss. The heating load of the hot water tank and the heat collection mechanism is reduced, the energy consumption of the circulating pump is reduced, and the overall energy efficiency of the system is improved. In a low temperature environment (such as winter), the heat preservation module can maintain the temperature fluctuation in the tank ≤±1℃, avoiding the decrease of microbial community activity due to temperature difference stress. The time for the fermentation tank 3 to rise from room temperature to the target temperature (such as 35℃) is shortened, thereby accelerating the start-up phase of anaerobic fermentation. In high-temperature fermentation (50-60℃), the heat preservation module can reduce the additional heating requirement; in medium-temperature fermentation (30-45℃), it can naturally dissipate heat. The metal fatigue problem of the tank body outer wall caused by temperature difference stress is reduced, and the corrosion rate is decreased.

[0048] Specifically, the heat preservation module is connected to the fermentation tank 3 by a clamping table or a screw. Through clamping table (buckle type) or screw connection, the heat preservation module can be quickly installed or removed, facilitating the maintenance of the heating body 11, valves, sensors or cleaning the outer wall of the fermentation tank 3. The clamping table or screw fixation ensures that the heat preservation module is in close contact with the surface of the tank body, reduces the air gap, and avoids the heat bridge effect (local heat dissipation) caused by loosening. Screw connection is suitable for heavy or high-pressure tank bodies, and clamping table type is suitable for lightweight or frequently maintained scenarios.

[0049] The heat preservation module is provided with a polyurethane layer. The thermal conductivity of polyurethane foam (PU) is low, which can effectively block the loss of heat to the outside. Compared with traditional rock wool or glass wool, polyurethane has lower density, reducing the additional weight of the tank body. The closed-cell structure of polyurethane blocks the penetration of water vapor, avoiding the corrosion of the tank body outer wall due to condensed water. Fireproof standards can be improved by adding flame retardants, suitable for flammable environment of biogas.

[0050] In one embodiment provided in the present disclosure, a limiting groove is provided on the fermentation tank 3, and the heating body 11 is embedded in the limiting groove. A groove (limiting groove) of a specific depth is processed on the inner wall / outer wall of the fermentation tank 3, and the heating body 11 (such as a metal heat-conducting pipe or an electric heating sheet) is embedded therein, flush with or slightly protruding from the surface of the tank body. The size of the limiting groove is matched with the heating body 11, ensuring close contact and avoiding loosening or displacement. The heating body 11 is in direct contact with the tank body through the limiting groove, reducing the contact thermal resistance and improving the heat transfer efficiency (compared with external heating). Compared with external heating band, the embedded design of the limiting groove avoids heat loss to the environment, especially suitable for high-temperature fermentation (50-60℃). In the stirring or pump circulation working condition, the limiting groove fixes the heating body 11, preventing loosening or breakage caused by vibration. The limiting groove is regularly distributed along the axial / circumferential direction of the tank body, making the layout of the heating body 11 more accurate and eliminating local cold / hot areas.

[0051] Further, the heating body 11 and the limiting groove are provided with a sealing glue layer. The sealing glue layer adopts a high-temperature-resistant and high-heat-conducting (thermal conductivity≥1.5 W / m·K) silicone sealing glue or a ceramic filled sealing glue. The micro voids between the heating body 11 and the limiting groove are filled, and the contact thermal resistance is reduced. The penetration of corrosive gases (such as H2S and water vapor) in the fermentation tank 3 to the joint of the heating body 11 is blocked. The elastic sealing glue absorbs the slight displacement caused by stirring or thermal deformation, and avoids the metal hard contact abrasion. After the sealing glue fills the gap, the tank wall temperature difference can be effectively reduced, and the activity stability of the methanogenic bacteria is improved. In the vibration condition, the displacement amount of the heating body 11 can also be reduced through the setting of the sealing glue.

[0052] In an embodiment provided by the present disclosure, referring to Figure 3 As shown in the figure, the fermentation tank 3 has a feed inlet and a discharge outlet, and the density of the heating body 11 in each heating module gradually decreases along the direction from the feed inlet to the discharge outlet. During the anaerobic fermentation process of organic waste, the organic waste successively experiences the three stages of hydrolysis, acid production and methane production along the flow direction, which adapts to the different requirements of temperature at each stage. The dense heating at the feed end makes the cellulose / lignin and other refractory substances quickly hydrolyze, and shortens the residence time. The moderate heating at the middle section avoids excessive accumulation of VFA (volatile fatty acid) and improves the pH stability. For materials containing straw and feces, the high temperature at the front end can break the wrapping effect, and the low temperature at the rear end can avoid the hardening of scum. When the feed concentration fluctuates, the system automatically adjusts the reaction rate through the temperature gradient, thereby improving the gas production stability.

[0053] Specifically, the density can decrease by 15% to 20% per meter of flow channel. Further, a temperature probe can be arranged at each density change node, for example, an optical fiber temperature measurement is adopted to avoid electromagnetic interference.

[0054] In an embodiment provided by the present disclosure, each heating module is arranged along the axial direction of the fermentation tank 3 with a length of L1, and the tank length of the fermentation tank 3 is L2, L2=(0.5-0.8)L1. By shortening the length of the heating module (relative to the tank length), a heating zone (L1) and a non-heating transition zone (L2-L1) are formed in the axial direction of the fermentation tank 3. The heating zone (L1) concentrates energy to maintain efficient hydrolysis / acidity; the transition zone (L2-L1) is suitable for the temperature of methane (30-38℃). The axial temperature difference promotes the natural partitioning of hydrolysis bacteria (front end) and methanogenic bacteria (rear end), and the population efficiency is improved by more than 20%.

[0055] Compared with full-tank-length heating, the transition zone provided by the present disclosure uses material residual heat to maintain the reaction and reduces the start-stop frequency of the heating module. The density difference (Δρ≈15 kg / m 3)Drive animal material circulation, reduce the stirring energy consumption reduction. When the concentration of the feed mutates, the transition zone plays a buffering role and can effectively reduce the fluctuation amplitude of the gas production. The surface humidity of the non-heating zone is higher, which avoids the hardening of dregs (especially for high-fat materials such as kitchen waste).

[0056] In an embodiment provided by the present disclosure, the modular heating device 1 further comprises a temperature detection mechanism and a pressure detection mechanism connected to the controller, the temperature detection mechanism is used to detect the current water temperature information in the heating body 11, and the pressure detection mechanism is used to detect the current water pressure information of the circulating water path, and the controller is further connected to the first electromagnetic valve and the circulating pump to correspondingly control the first electromagnetic valve and the circulating pump to perform corresponding actions according to the current water temperature information and the current water pressure information.

[0057] The temperature detection mechanism detects the water temperature of the heating body 11, feeds back to the controller to dynamically adjust the electromagnetic valve opening degree and the pump speed, and maintains the set temperature. By identifying the temperature difference of each heating module, the electromagnetic valve in the abnormal area is preferentially adjusted (local correction) to avoid overall system fluctuations. The temperature stability improves the metabolic efficiency of methanogens and can increase the methane concentration to a certain extent. According to the pre-adjustment of the heating power according to the feed temperature (such as 5℃ in winter and 25℃ in summer), the steam consumption can be reduced.

[0058] The pressure detection mechanism can provide high pressure protection, thereby reducing the pump speed and simultaneously relieving the pressure to reduce the risk of pipe explosion. When the pressure is less than 0.2 MPa, the leakage detection is triggered, and the staff can quickly locate the fault position according to the information of the controller and timely maintain, thereby reducing the waiting time. The circulating resistance can be intelligently adjusted by differential pressure calculation, thereby reducing the energy consumption. The pressure fluctuation frequency analysis (such as >5Hz prompting pipeline cleaning) prolongs the service life of the equipment.

[0059] Through the data fusion of temperature and pressure (such as high temperature and low pressure prompting vaporization, triggering emergency cooling), the controller can predict the trend (such as 0.1℃ / min temperature rise rate indicating overheating risk). Through the whole link closed loop of “monitoring-decision-execution”, the heating system is upgraded from passive operation and maintenance to intelligent pre-control, which becomes the core guarantee for the efficient and stable operation of the anaerobic fermentation equipment. In this way, when the water temperature is out of limit, the electromagnetic valve opening degree is preferentially adjusted (local correction); when the overall temperature deviation is greater than 2℃, the pump speed is adjusted (system level control). The control response delay is less than 30 seconds for the feed temperature fluctuation (such as low temperature raw materials in winter). When the pressure is greater than 0.8 MPa, the pump speed can be reduced to prevent pipe explosion; when the pressure is less than 0.2 MPa, the alarm is triggered to detect the leakage.

[0060] It should be noted that the term “and / or” appearing in the present text only describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can represent three cases of existence of A alone, existence of B alone, and existence of A and B simultaneously.

[0061] According to a second aspect of the present disclosure, a fermentation tank is provided.

[0062] The fermentation tank comprises the modular heating device 1 as in the first aspect, thus having the same technical effects as the modular heating device 1. Precise temperature control is conducive to maximizing microbial activity and improving methane yield. Through the synergistic arrangement of dynamic heat load distribution and insulation modules, the heating energy consumption is reduced.

[0063] According to a third aspect of the present disclosure, a premix processing device for a fermentation tank is provided.

[0064] The premix processing device for a fermentation tank comprises a feeding tank 21 for containing material, the feeding tank 21 having feeding processing areas 211, secondary processing areas 212 and feeding processing areas 213 arranged in a stepped manner, the two ends of the secondary processing areas 212 being respectively communicated with the feeding processing areas 211 and the feeding processing areas 213; the feeding processing areas 211, the secondary processing areas 212 and the feeding processing areas 213 are arranged in a stepped manner in sequence, so that the material can fall down; a mixing mechanism 22 is arranged in the feeding processing areas 211 for stirring the material and guiding the material from the feeding processing areas 211 to the secondary processing areas 212, and the dry matter content of the feeding processing areas 211 is 20% to 40%; a conveying mechanism 23 is arranged in the secondary processing areas 212 and the feeding processing areas 213 for stirring the material and guiding the material from the secondary processing areas 212 to the feeding processing areas 213; a pushing mechanism 24 is arranged in the feeding processing areas 213 for pushing the material into the fermentation tank 3; and a steam mechanism 25 has a plurality of nozzles arranged on the inner wall of the feeding processing areas 211 and facing the material for guiding hot steam onto the material.

[0065] The working principle of the premix processing device for a fermentation tank is that the material sequentially passes through the feeding processing areas 211, the secondary processing areas 212 and the feeding processing areas 213, and falls down naturally by using the height difference (stepped design), thereby reducing the mechanical conveying energy consumption. Specifically, in the feeding processing areas 211, the dry matter content is controlled to be 20% to 40%; in the secondary processing areas 212, the conveying mechanism 23 finely mixes (breaks up the agglomerates and homogenizes); in the feeding processing areas 213, the pushing mechanism 24 quantitatively pushes to the fermentation tank 3. The nozzles spray low-pressure saturated steam, and the steam quantity is dynamically adjusted through feedback of the temperature and humidity sensor.

[0066] The working process of the premixing material processing device 2 is as follows: in the feeding processing area 211, after the material enters, the mixing mechanism 22 (such as a paddle type stirrer) performs primary crushing, and the steam nozzle sprays hot steam. In the secondary processing area 212, the conveying mechanism 23 (such as a screw conveyor) further mixes and detects the uniformity of the material (through a NIR near-infrared sensor). In the feeding processing area 213, the hydraulic pushing mechanism 24 pushes the material into the fermentation tank 3 at a constant rate to avoid material impact.

[0067] Through the above technical solution, the material can be homogenized, the contact area of the microorganism is increased, and the hydrolysis time is shortened. Precise control of dry matter can increase the CH4 yield from 0.15 to 0.45 m 3 / kg VS. Steam pretreatment reduces pH fluctuations and avoids acidification collapse. Pathogen killing reduces H2S production. In cooperation with the modular heating device 1: the temperature of the premixed material is increased to 40℃-50℃, reducing the heating load of the fermentation tank 3. The premixing material processing device 2, through the innovative combination of "physical classification and thermal chemical conditioning", becomes a key front-end system for efficient and stable operation of the fermentation tank 3, especially suitable for complex composition and high solid content organic waste treatment scenarios.

[0068] Further, the nozzles arranged in the feeding processing area 211 are inclined, and the inclination angle of the nozzles relative to the horizontal direction gradually decreases from top to bottom. In this way, it is beneficial to make the steam spread as much as possible to fully contact with the material, thereby ensuring the pretreatment quality of the material and helping the material to ferment in the fermentation tank.

[0069] In an embodiment provided in the present disclosure, the steam mechanism 25 includes a steam generating unit, a steam cylinder and an injector which are sequentially communicated, the steam generating unit is used to provide steam; the injectors are arranged in multiple numbers and are arranged at intervals on the inner wall of the feeding processing area 211, and the injectors are one-to-one correspondingly communicated with the steam cylinder, wherein a pressure reducing valve is arranged between the steam cylinder and the injector, and the pressure reducing valve is in communication connection with the controller.

[0070] Working principle: high-pressure saturated steam is directly sprayed into the material (liquid / slurry) through the nozzle or perforated pipe, the high-speed flow of the steam forms a turbulent flow, and the steam is fully mixed with the material. After the steam contacts the low-temperature material, it condenses rapidly, releases latent heat, and the condensed water is mixed with the material, and at the same time, the sensible heat (temperature drop to the temperature of the material) of the steam also transfers part of the heat. Through stirring or natural convection, the heat is uniformly distributed to the entire feeding processing area 211.

[0071] The high-pressure steam generated by the steam generation unit is evenly distributed to multiple injectors to avoid uneven flow of each nozzle. The controller dynamically adjusts the pressure of each branch to adapt to the dry matter requirements of different materials. The high-speed steam is injected into the material to form a local turbulent flow, which is beneficial to directly heat the material by releasing latent heat when the steam condenses; and the condensed water replenishes the water content of the material. In this way, the pressure relief valve prevents the branch pressure from exceeding the limit to avoid the risk of pipe explosion.

[0072] The multiple injectors cover the full cross-section of the feed area, eliminating steam dead angles and reducing the standard deviation of the moisture content of the material. Steam instantaneously kills pathogenic bacteria (such as E. coli) and reduces the risk of spoilage in the fermentation tank 3. The steam distribution cylinder distributes steam as needed, which can save energy. The design of the injector promotes complete condensation of the steam, reducing heat loss. For high-viscosity materials (such as sludge), high-pressure injection breaks down the colloidal structure; for fibrous materials (such as straw): low-pressure steam avoids excessive hydrolysis. Through the dual use of latent heat and sensible heat, the steam energy conversion rate is improved. Coupled with the material sensor, millisecond dry matter closed-loop regulation and control is achieved.

[0073] Further, the feed treatment area 211 is provided with a second temperature detection mechanism communicatively connected to the controller, the second temperature detection mechanism being configured to detect current temperature information in the feed treatment area 211, and the controller being configured to control the working states of the pressure relief valve and the injector according to the current temperature information. The second temperature detection mechanism monitors the material temperature of the feed treatment area 211 in real time, forms a feedback signal and transmits it to the controller, dynamically adjusts the opening degree of the pressure relief valve and the start-stop of the injector, and can maintain accurate control of the set temperature ±1℃ (such as 55℃), avoiding energy waste or insufficient heating caused by excessive steam. The temperature signal is coupled with parameters such as dry matter content and steam pressure for calculation (for example, through the PID algorithm in the prior art), realizing multi-variable collaborative regulation and control. In this way, homogenization heating can be achieved, the temperature uniformity can reduce the difference in cellulose / starch hydrolysis rate; at the same time, pathogenic bacteria inactivation guarantee can be provided, and 55℃-60℃ (salmonella inactivation threshold) can be stably maintained, and the sterilization rate is greatly improved. In this way, steam heating can be transformed from "extensive supply" to "precise dosing"; the temperature signal is coupled with dry matter and pressure parameters to build an intelligent pretreatment model. This design realizes temperature feedback closed loop, making the premixing treatment device become an "intelligent constant temperature injector" of the fermentation system, which is especially suitable for processing high-value waste such as kitchen waste and livestock manure which are sensitive to temperature.

[0074] In one embodiment provided in the present disclosure, the mixing mechanism 22 comprises a first positioning shaft 221, a first helical blade 222, and a first motor 223. The first positioning shaft 221 is inserted into the feed treatment area 211 and connected to the feed tank 21 through a first bearing. The drive shaft of the first motor 223 is drivingly connected to the first positioning shaft 221, and the first helical blade 222 is helically arranged along the first positioning shaft 221 and fixedly connected to the positioning shaft.

[0075] Through the above technical scheme, the first spiral blade 222 is spirally arranged along the positioning shaft, and rotates by being driven by the motor, so that a bidirectional mixing effect of axial propulsion and radial diffusion is formed. In the axial direction, the blade slope pushes the material to move to the secondary treatment area 212; in the radial direction, the blade edge shearing force breaks the lumps, and realizes material tumbling. The speed gradient (blade tip > center) generated by the spiral blade promotes the interlayer friction of the material, and strengthens the mixing. Through the rotation of the spiral blade, the contact area of the steam with the material is increased by 35 times, and the heat and mass transfer efficiency is improved. The vortex generated by the spiral blade improves the steam penetration depth, so that the condensation heat utilization rate is improved, the forced mixing reduces the dry matter distribution standard deviation, meets the feeding requirements of the fermentation tank 3, and improves the gas production gain and operation stability of the fermentation tank 3.

[0076] In an embodiment provided in the present disclosure, the conveying mechanism 23 comprises a second motor 231 and a second spiral blade 232, wherein the second spiral blade 232 is arranged in the feed tank 21, and both ends of the spiral blade are rotatably connected to the feed tank 21 through second positioning shafts; the second motor 231 is drivingly connected to one of the second positioning shafts; when the second motor 231 rotates, the second positioning shaft drives the second spiral blade 232 to rotate, so as to push the material.

[0077] The fine homogenization of the material is realized by the low-speed rotation of the second spiral blade 232, and the lumps that are not sufficiently mixed in the front section are broken. The high-speed rotation provides stable thrust to press the material into the fermentation tank 3 at a constant flow rate (such as 2.5 t / h). The axial arrangement of the spiral blade reduces the height of the device and reduces the transverse torque acting on the main shaft. The homogenized feed is beneficial to increase the contact area of the microorganisms, and the peak methane yield is reached in advance. The stable flow rate can avoid sudden changes in the load of the fermentation tank 3, which is beneficial to reduce the pH fluctuation, thereby helping the fermentation work to be carried out stably and reliably.

[0078] In the present disclosure, the pushing mechanism 24 is provided as a utility model patent with the name of a straw livestock manure pumping system (publication number CN209456266U). Thus, the material is pushed into the fermentation tank.

[0079] In the present disclosure, the feed tank 21 comprises a tank cover and a tank body, the tank cover is formed in a structure matched with the tank body, and is movably arranged above the tank body. The tank cover is tightly attached to the tank body (optionally equipped with a silica gel sealing strip), so as to prevent dust (such as straw debris) or odor (H2S, NH3) from overflowing during the pretreatment process, and meet the environmental protection emission standard.

[0080] In a specific embodiment, the tank cover can be connected to the tank body through a hydraulic rod / hinge, so as to realize one-key opening and closing (opening and closing angle 70°-90°).

[0081] Further, a transparent window (such as a polycarbonate panel) can be provided on the box cover to monitor the material state in real time and avoid overfilling.

[0082] For easy operation, a handle is provided on the box cover. The handle (usually in U-shaped or horizontal strip design) provides a force point, and a single person can complete the opening and closing of the box cover.

[0083] Further, a corrugated anti-slip pattern or rubber coating can be used on the surface of the handle, and the holding force remains > 50N when operating with wet gloves.

[0084] In the present disclosure, the feed tank 21 is made of metal material, and at least the inner wall of the feed tank 21 has corrosion resistance. The inner wall is made of corrosion-resistant metal (such as 316L stainless steel) or corrosion-resistant coating (such as polytetrafluoroethylene PTFE), which can improve the resistance of the feed tank 21 and is beneficial to ensure the service life of the feed tank 21, while reducing the impact on the feed tank 21.

[0085] In one embodiment provided in the present disclosure, the bottom wall of the feed processing area 211 is provided with a weighing sensor 26 for weighing the current weight information of the material in the feed processing area 211; the weighing sensor 26 is communicatively connected to the controller, and the controller is communicatively connected to the mixing mechanism 22, the conveying mechanism 23, the pushing mechanism 24 and the steam mechanism 25, so as to correspondingly control the mixing mechanism 22, the conveying mechanism 23, the pushing mechanism 24 and the steam mechanism 25 to perform corresponding actions according to the current weight information of the material.

[0086] The weighing sensor 26 can monitor the weight of the material in the feed processing area 211 in real time, replace the traditional batch measurement method, and realize continuous dynamic weighing. The data of the weighing is fed back to the controller, and when the weight is overweight (such as the data of the weighing > 120% of the design value), an audible and visual alarm is triggered, and the feeding rate is automatically reduced. By accurately controlling the amount of feed, the organic loading rate (OLR) of the fermentation tank 3 is reduced, and the stability of the methane yield is increased. The steam injection amount is linearly adjusted according to the weight of the material, avoiding waste of "small material with large steam", and saving steam cost.

[0087] In the present disclosure, the feed processing area 211 is provided with a camera 27, and the camera 27 is communicatively connected to the controller. Based on the setting of the camera 27, the state of the material can be captured in real time by a high-definition camera (such as a 2 million pixel industrial camera), for example, observing the dryness and humidity of the material (analyzing by surface reflection), the size of the material lump (image segmentation algorithm detects > 5cm lump), and the mixing of foreign matters in the material (metal, plastic and other abnormal objects alarm), thereby recording the whole pre-treatment process and supporting playback analysis of fault causes. Through image analysis of dry matter distribution, the steam injection amount is dynamically optimized, energy consumption is reduced, and efficiency is improved. The detection of metal foreign matters avoids damage to subsequent equipment (such as spiral blades), reducing maintenance cost.

[0088] According to a fourth aspect of the present disclosure, there is provided an organic waste anaerobic fermentation device.

[0089] The organic waste anaerobic fermentation device comprises a fermentation tank 3 arranged on a base body, the fermentation tank 3 having a feed end and a discharge end arranged oppositely, wherein the feed end is provided with a premixing material treatment device 2, and the discharge end is provided with a discharge device 4; a stirring device 5 for stirring the material in the fermentation tank 3, the stirring device 5 comprising a main shaft 51 and stirring blades 52 arranged on the main shaft 51, wherein the main shaft 51 is arranged eccentrically relative to the fermentation tank 3, so that the distance between the stirring blades 52 and the top wall of the fermentation tank 3 is greater than the distance between the stirring blades 52 and the bottom wall of the fermentation tank 3; a micro-oxygen device 6 connected to the fermentation tank 3 for providing oxygen to the fermentation tank 3; and a modular heating device 1 arranged on the fermentation tank 3 for heating the material.

[0090] The working principle of the organic waste anaerobic fermentation device is as follows: in the pretreatment stage, the premixing material treatment device 2 homogenizes and conditions (controls the dry matter content to be 20%-40%) the raw material and kills pathogenic bacteria. In the main fermentation stage, the eccentric stirring and the modular heating device 1 maintain an anaerobic environment and promote the microbial chain reaction of hydrolysis-acid production-methane production. In the post-treatment stage, the discharge device 4 stably discharges the residue to avoid disturbing the active sludge layer.

[0091] Based on the eccentric arrangement of the main shaft 51, the main shaft 51 is offset from the center of the tank body, forming an asymmetric flow field (large gap at the top and small gap at the bottom), so that the large bubbles at the top are broken (enhancing gas-liquid mass transfer), and the strong shear force at the bottom can prevent sedimentation, and the precise injection of trace oxygen (DO<0.1mg / L) by the micro-oxygen device 6 can stimulate the activity of facultative bacteria and accelerate hydrolysis.

[0092] During the fermentation process, the large gap at the top can prevent the scum layer from blocking the stirring shaft, while promoting biogas release; and the small gap at the bottom can prevent sand and stone from depositing and reduce the wear rate. By pulse oxygen supply, the hydrolysis efficiency is improved without damaging the anaerobic environment. The modular heating device 1 (such as a hot water jacket) is linked with stirring to improve temperature uniformity. Eccentric stirring increases the contact area of cellulose, reducing the hydrolysis time; micro-oxygen stimulation increases the activity of methanogenic bacteria, and the proportion of CH4 is improved. Temperature and stirring are cooperatively controlled, and pH fluctuation is reduced.

[0093] In an embodiment provided in the present disclosure, the stirring device 5 comprises a driving motor for providing driving force, a main shaft 51 arranged in the fermentation tank 3 and rotatably connected to the fermentation tank 3 at both ends thereof through a second bearing, and a plurality of stirring blades 52, each comprising a connecting rod 521 and a material starting body 522, wherein the connecting rod 521 is spirally arranged along the axis direction of the main shaft 51, and both ends of the connecting rod 521 are fixedly connected to the main shaft 51 and the material starting body 522, respectively.

[0094] The working principle of the stirring device 5 is that the helically arranged connecting rod 521 pushes the material to move along the direction of the main shaft 51, forming a longitudinal circulation (speed 0.3-0.6 m / s). The rotating material lifting body 522 generates centrifugal force, causing the material to be radially dispersed to the tank wall. The bowl-shaped structure of the material lifting body 522 scoops up the bottom sediment on the rising side, realizing the exchange of bottom and top materials. The continuous curved surface of the spiral connecting rod 521 destroys the laminar boundary layer, so that the high solid material can still be effectively mixed. When the material lifting body 522 rotates, a low-pressure area is formed at the back, promoting the separation of biogas bubbles.

[0095] The driving motor starts at low speed to avoid damage to the bearing due to sudden torque increase. The material lifting body 522 sweeps the tank bottom and lifts the settled sludge to the middle and upper parts; the spiral connecting rod 521 pushes the material to move axially; and the edge of the material lifting body 522 breaks large bubbles.

[0096] In actual application, the material lifting body 522 can be periodically reversed (5 rpm, 30 seconds) to clean the entangled fibers on the back side, thereby ensuring its use effect.

[0097] The bowl-shaped structure (usually with a diameter of 1 / 3 of the length of the main shaft 51) has a gap of 10-15 mm with the tank bottom, forming a forced sweeping effect to prevent the bottom material from being anaerobically consolidated (common in livestock and poultry manure fermentation). When the material lifting body 522 rotates, Taylor vortexes are generated, increasing the contact area between biogas and liquid.

[0098] Further, serrations can be provided on the bowl edge of the material lifting body 522 to break the foam layer and prevent scum accumulation.

[0099] Further, along the rotation direction of the main shaft 51, the material lifting body 522 has opposite first and second material contact surfaces 5221 and 5222, wherein the extension length of the second material contact surface 5222 is greater than that of the first material contact surface 5221. The asymmetric structure of the material lifting body 522 can cause the first contact surface (short side) to quickly cut into the material, reducing the starting resistance; and the second contact surface (long side) can extend the action time, forming a sustained lift (similar to the Bernoulli effect of an airfoil).

[0100] When the material lifting body 522 rotates, it generates an asymmetric vortex. For the short side, a high-speed zone can be formed to break up lumps; and for the long side, a low-pressure zone (suction effect) can be formed to lift the bottom material. The short-side first contact surface reduces the direct impact with the sediment, reducing the wear rate, and the long-side second contact surface scoops up the sediment in a "bucket" shape, improving the conveying efficiency. Thus, the short side bears the shearing function and the long side lifts the material, which is beneficial to the tail vortex generated at the end of the long side to promote biogas release and shorten the bubble residence time.

[0101] Further, the opening size of the feeding body 522 gradually increases in the radial direction away from the main shaft 51. The gradually expanding opening forms a diffusion flow channel, so that the flow rate of the material decreases when it leaves the main shaft 51; the flow direction changes from radial to axial. For the near-axis area (small opening), high shear breaks the fiber clumps; and for the far-axis area (large opening), low shear protects the methanogen floc.

[0102] The gradually expanding structure reduces fluid separation loss and can achieve better energy saving than the straight cylinder blade. The small opening end can form strong disturbance to update the boundary layer material; and the large opening end can form a wide flow field to cover the far-end dead zone. High-density materials such as sand and gravel are concentrated in the small opening area for crushing; light-weight fibers are uniformly dispersed along the large opening flow channel.

[0103] In an embodiment provided in the present disclosure, the spacing of the stirring blade 52 relative to the bottom wall of the fermentation tank 3 is at least 1 meter, and the spacing of the stirring blade 52 relative to the top wall of the fermentation tank 3 is at least 1.5 meters.

[0104] The large gap at the bottom (≥1m) can reserve enough space to accommodate the sediment layer (such as sand and gravel, and refractory solids), avoiding direct scraping of the stirring blade 52. This can reduce wear and tear and improve blade life. For the bottom of the blade, a low-speed circulating area (0.1-0.3m / s) can be formed, allowing heavy particles to settle naturally, and light materials to be sucked up. The large gap at the top (≥1.5m) can provide a gas-liquid separation space, thereby providing an expansion area for biogas bubbles, increasing the diameter of the bubbles and the rising speed; and in the crushing area, the blade can rotate to shear large bubbles, improving the release rate. In this way, the blade disturbance can be prevented from causing the scum layer to break and reduce foam entrainment.

[0105] By dividing the vertical space of the tank body into a sedimentation area (bottom), a reaction area (middle), and a separation area (top), it is helpful to help the material to ferment efficiently; and the spacing can better match the settling characteristics of microorganisms; the bottom gap acts as a "safety buffer zone" to prevent the stirring from being overloaded.

[0106] In an embodiment provided in the present disclosure, the organic waste anaerobic fermentation equipment further comprises a limiting device, the limiting device comprising a support frame and a third bearing, the support frame being fixedly arranged in the fermentation tank 3; the third bearing being coaxially arranged relative to the main shaft 51 and connected to the support frame; and the main shaft 51 being inserted into the inner ring of the third bearing.

[0107] The limiting device can provide dynamic support. Specifically, when the main shaft 51 rotates, the third bearing inner ring rotates with the main shaft 51, and the outer ring is fixed to the tank body through the support frame, thereby restricting the radial runout of the main shaft 51; at the same time, the bearing end face cooperates with the shoulder of the main shaft 51 to prevent the axial movement of the stirring blade 52. The bending moment generated by the stirring torque is dispersed to the tank wall through the support frame, which can avoid stress concentration at the root of the main shaft 51. When the torque suddenly increases due to the sudden thickening of the material (such as fiber winding), the bearing temperature sensor triggers an alarm. In this way, the swing of the main shaft 51 can be limited to make the stirring flow field more stable, the deflection of the main shaft 51 is controlled within a certain range by the support frame, and mechanical vibration is reduced.

[0108] In an embodiment provided in the present disclosure, the inclination angle of the fermentation tank 3 is 1‰-3‰ of the total length of the fermentation tank body. The setting of the inclination angle can make the bottom sediments (such as sand and stones and refractory solids) slide along the inclined plane to the low-lying sludge collection area, avoiding the accumulation of the whole tank bottom, and reducing the thickness of the sediment layer from 30-50 cm to 10-15 cm. The light liquid phase flows to the high position under the action of the gravity component, forming a continuous microcirculation, promoting the contact between the material and the microorganism, and reducing the stirring dead angle.

[0109] In an embodiment provided in the present disclosure, the micro-oxygen device 6 is arranged in two groups and is arranged at the feeding end of the fermentation tank 3. The air nozzle of the micro-oxygen device 6 is arranged in the lower area of the fermentation tank 3 and is arranged in a spaced manner relative to the stirring blade 52.

[0110] The arrangement of the micro-oxygen device 6 can inject a small amount of oxygen (DO 0.05-0.1 mg / L) at the organic matter hydrolysis stage (feeding end) to stimulate the activity of facultative bacteria (such as Bacillus) and improve the cellulose decomposition rate, and at the same time, the volatile fatty acid (VFA) conversion efficiency is improved. The micro-oxygen device 6 is arranged in a spaced manner relative to the stirring blade 52 to avoid the direct shearing escape of the airflow by the blade. The oxygen supply design realizes “precise positioning and trace control of biological synergy”, decouples the hydrolysis and methanation stages, and improves the overall efficiency.

[0111] In an embodiment provided in the present disclosure, the discharging device 4 comprises a third motor and a third spiral blade, wherein the third spiral blade is arranged in the fermentation tank 3, and one end of the spiral blade is connected to the fermentation tank 3 through a third positioning shaft; the third motor is drivingly connected to the third positioning shaft; when the third motor rotates, the third positioning shaft drives the third spiral blade to rotate, so as to push the material out of the fermentation tank 3.

[0112] The discharge device 4 adopts a variable pitch design (large pitch at the feeding end and small pitch at the discharging end), and when rotating, the large pitch quickly collects the material (flow rate 0.4-0.6 m / s) ; and the gradually reduced pitch can increase the pushing pressure (up to 0.15 MPa), overcoming the liquid level resistance in the fermentation tank 3. The gap between the blade and the tank wall is ≤3 mm, preventing backflow of the material. The third motor is started at low speed (15 rpm), avoiding hydraulic impact. The spiral blade pushes the fermentation residues from the tank bottom to the discharge port, and at the same time, the extrusion effect causes the free liquid to flow back to the reaction zone; the low-pressure area on the back of the blade promotes the desorption of residual biogas.

[0113] In the present disclosure, the organic waste anaerobic fermentation equipment further comprises a detection device communicatively connected to the controller, the detection device comprising one or more of a pressure sensor, a liquid level detector, a temperature sensor, and a torque sensor, wherein the pressure sensor is used to detect the current pressure information in the fermentation tank 3, the liquid level detector is used to detect the current liquid level height in the fermentation tank 3, the temperature sensor is used to detect the current temperature information in the fermentation tank 3, and the torque sensor is arranged on the main shaft 51 and / or the stirring blade 52 and is used to detect the current torque information; the detection device further comprises one or more of a methane sensor, a pH sensor, a hydrogen sulfide sensor, and a CO2 / O2 concentration analyzer.

[0114] When the temperature sensor detects abnormal heating (such as >60℃), the automatic adjustment modular heating device 1 is adjusted and the pressure is released, avoiding the “overheating gas sudden increase overpressure” chain reaction. When the pH <6.2 and the ORP >200 mV, the alkali dosing system is triggered to prevent acidification collapse.

[0115] When the torque sensor detects an increase in viscosity (such as fiber accumulation), the stirring speed is automatically increased (by 10%) to avoid local precipitation.

[0116] The methane sensor controls the micro-oxygen device 6 in real time, so that the DO in the hydrolysis stage is stabilized at 0.05-0.1 mg / L, and the hydrolysis rate is improved. When the CO2 / O2 analyzer detects that CO2 >40%, the feeding rate or pH is automatically adjusted to increase the CH4 proportion to >60%.

[0117] When the pressure sensor detects a sudden drop in air pressure (such as pipeline leakage), the air inlet valve can be quickly closed and an alarm can be sounded.

[0118] The liquid level detector identifies abnormal rise of foam. The torque trend analysis predicts the bearing wear of the main shaft 51, and maintenance is arranged in advance.

[0119] In one embodiment provided in the present disclosure, the micro-oxygen device 6 and the discharge device 4 are both provided in two groups and are arranged in the lower region of the fermentation tank 3.

[0120] Two groups of gas nozzles of the micro-aerobic device 6 are diagonally distributed in the lower part of the fermentation tank 3, covering 80% of the cross-sectional area, and forming cross air flow. The double-helix discharge shafts are arranged in parallel to realize bidirectional pushing of the material and improve the residue discharge efficiency. When one of the two groups of micro-aerobic devices 6 fails, the other group of micro-aerobic devices 6 can still maintain 50% of the processing capacity, thereby ensuring the reliability of the system during operation. The two groups of gas nozzles work together to optimize the dissolved oxygen (DO) gradient from 0.05-0.3 mg / L (single group) to 0.08-0.15 mg / L (double groups), and the facultative bacteria activity is improved.

[0121] It should be noted that the pressure sensor, liquid level detector, temperature sensor, torque sensor, methane sensor, pH sensor, hydrogen sulfide sensor and CO2 / O2 concentration analyzer appearing in the present disclosure are all detection instruments in the prior art. Those skilled in the art can select any suitable detection instrument according to actual needs.

[0122] According to a fifth aspect of the present disclosure, a process method of an organic waste anaerobic fermentation equipment is provided.

[0123] The process method of the organic waste anaerobic fermentation equipment includes the following steps: conveying the material into the fermentation tank 3; obtaining first material information in the fermentation tank 3, the first material information including current gas component information, gas temperature information, gas humidity information and gas pressure information; obtaining second material information in the fermentation tank 3, the second material information including material temperature information and material solid-liquid ratio information; and controlling the premixing material treatment device 2, the stirring device 5, the micro-aerobic device 6, the modular heating device 1 and the discharge device 4 to perform corresponding actions respectively according to the first material information and the second material information.

[0124] The specific process flow of the organic waste anaerobic fermentation equipment is as follows:

[0125] The material enters through the premixing material treatment device 2 (ladder type feeding box 21), is steam conditioned (controlling dry matter 20%-40%), and is broken and homogenized by the mixing mechanism 22 (screw blade).

[0126] The amount of steam is dynamically adjusted according to the feedback of the weighing sensor 26; and the mixing speed (20-60 rpm) is automatically adjusted based on the material viscosity (torque sensor).

[0127] Two groups of micro-aerobic devices 6 inject a small amount of oxygen (DO 0.05-0.1 mg / L) at the lower part of the feeding end to stimulate the activity of facultative bacteria.

[0128] After the material enters the fermentation tank 3, the eccentric stirring device 5 (main shaft 51 and screw blade) operates to form a three-dimensional flow field. At the top (gap 1.5 m), it is a degassing zone that can break large bubbles; and at the bottom (gap 1 m), it is a strong shear zone that prevents sedimentation.

[0129] The double-screw discharging device 4 extrudes the residue, and the free liquid returns to the reaction zone.

[0130] The torque sensor prevents overload, and the liquid level detector prevents overflow.

[0131] Through the above process method, the whole process optimization of "precise pretreatment intelligent fermentation efficient recovery" can be realized, the closed-loop control based on multi-sensor feedback can be realized, and the complex raw material fluctuation can be adapted. Therefore, the biogas quality and the residue heat value are improved, a new path of energy utilization is opened, and the organic waste is particularly suitable for large-scale treatment of high solid content, high sulfur and high fiber.

[0132] Finally, it should be pointed out that the utility model is not limited to the above optional embodiments, and anyone can derive other various forms of products under the inspiration of the utility model. The above specific embodiments should not be understood as limiting the protection scope of the utility model, and the protection scope of the utility model should be defined in the claims, and the specification can be used to explain the claims.

Claims

1. An anaerobic fermentation device for organic waste, characterized in that, include: A fermenter is mounted on a substrate. The fermenter has an inlet end and an outlet end that are arranged opposite to each other. The inlet end is equipped with a premix processing device, and the outlet end is equipped with an outlet device. A stirring device is used to stir the material in a fermentation tank. The stirring device includes a main shaft and stirring blades disposed on the main shaft. The main shaft is eccentrically disposed relative to the fermentation tank, such that the distance between the stirring blades and the top wall of the fermentation tank is greater than the distance between the stirring blades and the bottom wall of the fermentation tank. A micro-oxygenation device, connected to the fermenter, is used to supply oxygen to the fermenter; and, A modular heating device is installed on the fermentation tank for heating the materials.

2. The anaerobic fermentation equipment for organic waste according to claim 1, characterized in that, The stirring device includes: A drive motor, used to provide driving force; A main shaft, disposed within the fermenter, with both ends rotatably connected to the fermenter via second bearings; and, Multiple stirring blades are provided, each of which includes a connecting rod and a material lifting body. The connecting rod is spirally arranged along the axial direction of the main shaft, and both ends of the connecting rod are fixedly connected to the main shaft and the material lifting body, respectively.

3. The anaerobic fermentation equipment for organic waste according to claim 2, characterized in that, Along the rotation direction of the main shaft, the lifting body has a material contact surface and a material contact surface that are opposite to each other, wherein the extension length of the material contact surface is greater than the extension length of the material contact surface.

4. The anaerobic fermentation equipment for organic waste according to claim 2, characterized in that, Along the radial direction away from the main shaft, the opening size of the lifting body gradually increases.

5. The anaerobic fermentation equipment for organic waste according to claim 1, characterized in that, The distance between the stirring blades and the bottom wall of the fermentation tank is at least 1 meter, and the distance between the stirring blades and the top wall of the fermentation tank is at least 1.5 meters.

6. The anaerobic fermentation equipment for organic waste according to claim 1, characterized in that, The anaerobic fermentation equipment for organic waste also includes a limiting device, which includes a support frame and a third bearing. The support frame is fixedly installed in the fermentation tank. The third bearing is coaxially arranged with respect to the main shaft and connected to the support frame. The main shaft is inserted into the inner ring of the third bearing.

7. The anaerobic fermentation equipment for organic waste according to claim 1, characterized in that, The inclination angle of the fermentation tank is 1‰ to 3‰ of the total length of the fermentation tank.

8. The anaerobic fermentation equipment for organic waste according to claim 1, characterized in that, The micro-oxygen device is configured in two sets, both located at the feed end of the fermenter. The air nozzle of the micro-oxygen device is located in the lower part of the fermenter and is spaced apart from the stirring blades.

9. The anaerobic fermentation equipment for organic waste according to claim 1, characterized in that, The discharge device includes a third motor and a third spiral blade. The third spiral blade is disposed in the fermentation tank, and one end of the spiral blade is connected to the fermentation tank through a third positioning shaft. The third motor is driven to the third positioning shaft. When the third motor rotates, the third positioning shaft drives the third spiral blade to rotate, so as to push the material out of the fermentation tank.

10. The anaerobic fermentation equipment for organic waste according to any one of claims 1 to 9, characterized in that, The anaerobic fermentation equipment for organic waste also includes a detection device connected to the controller. The detection device includes one or more of a pressure sensor, a liquid level detector, a temperature sensor, and a torque sensor. The pressure sensor is used to detect the current pressure information in the fermentation tank, the liquid level detector is used to detect the current liquid level height in the fermentation tank, the temperature sensor is used to detect the current temperature information in the fermentation tank, and the torque sensor is disposed on the main shaft and / or the stirring blades to detect the current torque information. The detection device also includes one or more of the following: a methane sensor, a pH sensor, a hydrogen sulfide sensor, and a CO2 / O2 concentration analyzer.

Images