Continuous high-solid-content anaerobic fermentation equipment and use method thereof

Abstract

The invention discloses continuous high-solid-content anaerobic fermentation equipment and a use method thereof, and belongs to the technical field of waste treatment and resource utilization. Comprising a horizontal anaerobic fermentation bin, a hydraulically-driven plug-flow type low-speed strong mixing and stirring system arranged in the horizontal anaerobic fermentation bin, a multi-material collaborative feeding system and a temperature and power collaborative control system. The stirring mode of a speed reducer is abandoned, low-speed strong mixing stirring driven by hydraulic pressure is adopted, and meanwhile, the angle, spacing and distribution form of stirring blades on a stirring shaft are designed, so that the spacing of the blades is 50cm, the plane and the axial direction of the blades form 67 degrees, and clockwise single-side blades form 90 degrees in sequence; according to the design, no dead zone exists in the transmission process of 20% + / -10% high-solid-content materials and the low stirring process of 1 DEG C / second, low-energy-consumption sufficient mixing of the high-solid-content organic solid waste is achieved, and sufficient fermentation of each material in the fermentation bin is guaranteed; and meanwhile, the materials can be continuously treated, and the generated fermentation residues can realize full-amount composting.

Description

Technical Field

[0001] The present invention relates to the technical field of waste treatment and resource utilization, and in particular to a continuous high-solid content anaerobic fermentation equipment and a use method thereof. Background Art

[0002] At present, my country's organic waste is characterized by large output and many types. The sources of waste are diverse, mainly including kitchen waste, garden waste, sludge from urban sewage treatment plants, human feces, and livestock and poultry manure and straw in agricultural waste. Relevant statistics show that my country produces about 3.8 billion tons of livestock and poultry manure and about 1 billion tons of crop straw each year, and it is urgent to explore an efficient and coordinated treatment solution.

[0003] The development and utilization of biomass energy has become a hot topic for research and development in various countries. As one of the important ways to develop and utilize biomass energy, anaerobic fermentation technology plays an important role in the treatment and utilization of biomass resources such as agricultural waste and urban garbage with its advantages of high energy efficiency, low pollution and renewability. At present, my country's biogas anaerobic fermentation is mainly based on wet anaerobic fermentation such as CSTR. Although the technology is relatively mature, there are still problems such as low volumetric gas production rate, high energy consumption, high water consumption, large wastewater production and difficulty in treatment. The more advanced biogas projects abroad mostly use dry fermentation technology with a solid content greater than 20%. Dry anaerobic fermentation has the following advantages: 1) Low water demand, less biogas liquid produced, and reduced treatment costs; 2) High volumetric yield and high organic load rate per unit volume; 3) Pretreatment of organic solid waste is relatively simple. However, traditional dry anaerobic fermentation also has certain defects: 1) It is mainly based on batch processes such as composting and leaching, which makes heat and mass transfer difficult and the fermentation efficiency low; 2) Some continuous dry fermentation is subject to the level of automatic control, and the stirring device used is severely worn in contact with the solid raw materials, and there is a large stirring dead angle. In addition, most of them use reducer stirring, which has a fast stirring speed and high energy consumption; 3) The anaerobic fermentation microorganisms are not in uniform contact with the reaction substrate, and the fermentation cycle is long; 4) The moisture content of the material is low, and there is serious heterogeneity.

[0004] High-solid content anaerobic fermentation technology not only has the advantages of dry anaerobic fermentation, but also can effectively solve the problems of low heat transfer efficiency, uneven mass transfer, large equipment wear, and uneven contact between substrate and inoculum. However, the current high-solid content anaerobic fermentation reactor is only used to treat organic solid waste with a solid content of about 10% and 25%. The solid content of about 10% is too low, which will produce a large amount of biogas slurry and increase the treatment cost. The solid content of about 25% is too high, the equipment cost is high, and the homogeneity is poor. For example, there is a "high-solid content fully mixed anaerobic reactor (CN202211385495.5)", which processes materials with a solid content of about 10%. It is only suitable for small fermentation systems and has a low level of intelligent control. The processing volume is about 10L, and it is difficult to continuously process organic solid waste, and the fermentation residues need to be further filtered. The "Horizontal flow anaerobic digestion reaction device and method for treating high-solid content kitchen waste (CN202011300516.X)" is mainly aimed at the treatment of high-solid content kitchen waste with a solid content ≥25%. It is equipped with multiple stirring devices, has a complex structure, and high energy consumption, which increases the difficulty of waste treatment and reduces the treatment efficiency.

[0005] Therefore, the development of an anaerobic fermentation reactor with a high level of automation control, the ability to continuously process multiple organic solid wastes, a simple structure, easy adjustment of the properties of the initial materials, and uniform stirring has become an urgent need to promote the development of the industry. Summary of the invention

[0006] The purpose of the present invention is to provide a continuous high-solid content anaerobic fermentation equipment and a method of using the same, so as to solve the problems mentioned in the above background technology, such as the complex structure, low level of intelligent control, poor homogeneity, and difficulty in continuously treating multiple organic solid wastes of the current high-solid content anaerobic fermentation reactor. The equipment can continuously treat multiple organic solid wastes with high solid content, and the organic solid wastes are fully mixed in the reactor. The fermentation residues produced can be fully composted, and the equipment is equipped with an integrated intelligent control system.

[0007] To achieve the above object, the present invention provides a continuous high solid content anaerobic fermentation equipment, comprising: Multi-material coordinated feeding system, used to treat multi-organic solid waste with high solid content; A horizontal anaerobic fermentation chamber is connected to the multi-material coordinated feeding system through a conveying pipeline and is used to ferment the treated high-solid content multi-organic solid waste; A hydraulically driven plug-flow low-speed strong mixing and stirring system is arranged in the horizontal anaerobic fermentation chamber and is used to stir multi-organic solid waste with high solid content; The temperature and power coordinated control system drives the hydraulically driven plug-flow low-speed strong mixing and stirring system and the multi-material coordinated feeding system.

[0008] Preferably, the hydraulically driven plug-flow low-speed strong mixing and stirring system comprises a stirring shaft disposed in the fermentation box, stirring blades are evenly distributed on the stirring shaft, one end of the stirring shaft is connected to the stirring box through a first bearing seat, and the other end passes through the fermentation box through a second bearing seat and is connected to an external hydraulic drive device, and the hydraulic drive device is connected to a hydraulic station. The use of hydraulic stirring to provide power transmission avoids the original reducer stirring method, and effective stirring can be achieved under low-speed conditions, avoiding energy waste and saving energy consumption.

[0009] Preferably, the axial spacing of each stirring blade on the stirring shaft is 50 cm, there is only one single-sided stirring blade at each blade point on the stirring shaft, each stirring blade is arranged clockwise at an angle of 90° to the stirring blade on the axial direction, and the plane of the stirring blade is distributed on the stirring shaft at an angle of 67° to the axial direction. The use of hydraulic stirring combined with the angle, spacing, and shape design of the stirring blade can achieve uniform and dead-angle-free stirring of the material under slow stirring conditions, saving energy consumption while improving stirring efficiency, thereby improving the fermentation efficiency of the device.

[0010] Preferably, the rotation speed of the stirring shaft is 1° per second, three revolutions per hour, and each revolution takes 6 minutes.

[0011] Preferably, the diameter of the stirring shaft is 27.3 cm, the stirring blade is a long strip with a 1 / 4 circle at the top and parallel sides, the blade width of the stirring blade is 20 cm, and the centerline length of the stirring blade is 37.2% of the height of the horizontal anaerobic fermentation chamber.

[0012] Preferably, the horizontal anaerobic fermentation chamber comprises a fermentation box body, an observation port and a biogas outlet are arranged on the top of the fermentation box body, and an electric auxiliary heating component and a radar liquid level detection device are arranged inside the fermentation box body.

[0013] Preferably, the multi-material collaborative feeding system includes a feeding bin, which is connected to an external water pipeline. An automatically controlled spiral stirring shaft is provided in the feeding bin, the top of the spiral stirring shaft is connected to a motor output shaft, and a conveying screw pump is provided at the bottom of the feeding bin, so that one person can easily complete all feeding work.

[0014] Preferably, the temperature and power coordinated control system includes an intelligent control system, which integrates a hydraulically driven plug-flow low-speed intensive mixing and stirring system, a multi-material coordinated feeding system and an electric auxiliary heating component for integrated control.

[0015] The present invention also provides a method for using the above-mentioned continuous high-solid content anaerobic fermentation equipment, comprising the following steps: Step 1: During the initial fermentation, anaerobic sludge is added into the feed bin, and the delivery screw pump is turned on to deliver the inoculum to the fermentation tank until the volume of the inoculum in the fermentation tank reaches 1 / 3 of the volume of the fermentation tank; Step 2: Heat the temperature of the fermentation box to 35±1°C or 55±1°C through the electric auxiliary heating component; Step 3: Add 1-2m3 of water into the feed bin every day. 3 For high-solid content multi-organic solid waste, open the water pipeline to adjust the solid content to 15%-20%, use the spiral stirring shaft to stir it evenly, then turn on the delivery screw pump to transport it to the fermentation box, and use the stirring shaft of the hydraulically driven plug flow low-speed strong mixing and stirring system to stir it; Step 4: When the internal material of the fermentation box reaches 2 / 3 of the box volume, turn on the discharge motor and regularly output the same volume of anaerobic fermentation residue from the discharge port according to the feed amount.

[0016] Therefore, the present invention adopts the above-mentioned continuous high solid content anaerobic fermentation equipment and its use method, and the specific beneficial effects are as follows: (1) The stirring system of the present invention adopts a hydraulically driven single-axis plug-flow stirring system, and combines the angle, spacing, and shape design of the stirring blades on the stirring shaft. The operation effect is measured by simulation, and the solid content in different areas is measured to measure the actual operation effect. It has been verified that it has the advantages of simple structure, few stirring dead angles, and low energy consumption. It can achieve uniform stirring of materials without dead angles under low-speed stirring conditions, save energy consumption, and improve stirring efficiency, thereby improving the fermentation efficiency and overall energy efficiency of the device; (2) The device of the present invention can realize continuous treatment of multi-organic solid waste with high solid content, which helps to reduce the waiting time between batches and improve the consistency and stability of the overall treatment process; (3) The feed port of the present invention adopts a multi-material collaborative feeding system. The material input feed port can easily adjust the moisture content of the material, and accelerate the input of high-solid content materials into the fermentation bin through spiral stirring, so as to better realize the continuous automatic processing and automatic feeding of multi-materials. One person can complete all operations; (4) The present invention uses intelligent integrated control of stirring time and real-time detection of key anaerobic fermentation parameters such as the temperature of the horizontal anaerobic fermentation chamber by radar, thereby ensuring uniform temperature in the fermentation chamber, avoiding local high temperature, achieving precise heating, reducing energy consumption, and coordinating control of the feeding / discharging device, which is simple and convenient to operate; (5) The biogas generated by the present invention is directly used to generate electricity, which is used to power the electric auxiliary heating components of the system, thereby improving the energy efficiency and environmental benefits of the entire system.

[0017] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a front view of the equipment provided by Example 1 of the present invention; Figure 2 is a side view of the equipment provided by Example 1 of the present invention; Figure 3 is the volumetric gas production rate of anaerobic fermentation during continuous feeding of the equipment provided in Example 2 of the present invention; Figure 4 is the anaerobic fermentation methane concentration during the continuous feeding period of the equipment provided in Example 2 of the present invention; Figure 5 is a velocity cloud diagram of an anaerobic fermentation reactor provided in Example 2 of the present invention; Reference numerals 1. Power support plate; 2. Hydraulic drive device; 3. Second bearing seat; 4. Frame; 5. Stirring shaft; 6. Fermentation box; 7. Stirring blades; 8. Biogas outlet; 9. Observation port; 10. First bearing seat; 11. Discharge port; 12. Conveying screw pump; 13. Feed bin; 14. Hydraulic station; 15. Spiral stirring shaft; 16. Water pipeline; 17. Motor; 18. Feed port; 19. Conveying pipeline; 20. Intelligent control system; 21. Electric auxiliary heating component. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0020] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] Example 1 like Figure 1-2As shown, this embodiment discloses a continuous high-solid content anaerobic fermentation equipment, including a horizontal anaerobic fermentation tank, a hydraulically driven plug-flow low-speed strong mixing and stirring system arranged in the horizontal anaerobic fermentation tank, a multi-material coordinated feeding system, and a temperature and power coordinated control system. The high-solid content multi-organic solid waste is transported to the horizontal anaerobic fermentation tank through the multi-material coordinated feeding system through the conveying pipeline 19, and then the high-solid content multi-organic solid waste is mixed and fermented with the inoculum through the hydraulically driven plug-flow low-speed strong mixing and stirring system, so as to ensure that each organic solid waste in the horizontal anaerobic fermentation tank is fully fermented and the fermentation quality is guaranteed. The temperature and power coordinated control system drives the hydraulically driven plug-flow low-speed strong mixing and stirring system and the multi-material coordinated feeding system.

[0022] The multi-material coordinated feeding system is used to process multi-organic solid waste with high solid content, and includes a feeding bin 13, the feeding bin 13 is connected to an external water pipe 16, a spiral stirring shaft 15 is arranged in the feeding bin 13, the top of the spiral stirring shaft 15 is connected to the output shaft of the motor 17, and a conveying screw pump 12 is arranged at the bottom of the feeding bin 13. Multi-organic solid waste can be directly input into the feeding bin 13, and water is conveyed through the water pipe 16 to adjust the water content to a suitable water content, and the spiral stirring shaft 15 is used to accelerate the input of materials into the horizontal anaerobic fermentation bin to increase the material feeding rate.

[0023] The lower end of the horizontal anaerobic fermentation tank is provided with a feed port 18, which is connected to the multi-material coordinated feed system through a conveying pipe 19, and includes a fermentation box 6, and two circular observation ports 9 and a biogas outlet 8 are provided above the fermentation box 6. The biogas outlet 8 is provided at the center of the upper part of the fermentation box 6, and the observation ports 9 are respectively provided on both sides of the biogas outlet 8. A frame 4 is provided outside the fermentation box 6, and electric auxiliary heating components 21 are provided on the left, right and lower sides of the fermentation box 6, and the electric auxiliary heating components 21 are composed of a heating pipe and insulation cotton.

[0024] The hydraulically driven plug-flow low-speed strong mixing and stirring system comprises a stirring shaft 5 arranged in a fermentation box 6, 16 stirring blades 7 are evenly distributed on the stirring shaft 5, the axial spacing of each stirring blade on the stirring shaft 5 is 50 cm, there is only one single-side stirring blade 7 at each blade point of the stirring shaft 5, each stirring blade 7 is arranged clockwise in sequence at an angle of 90° with a stirring blade 7 on the axial direction, and the stirring blades 7 are distributed on the stirring shaft 5 at an angle of 67°. One end of the stirring shaft 5 is connected to the stirring box through the first bearing seat 10, and the other end passes through the fermentation box 6 and is connected to the outer hydraulic drive device 2 through the second bearing seat 3. The hydraulic drive device 2 is fixed on the power support plate 1, and the lower end of the hydraulic drive device 2 is connected to the hydraulic station 14 to provide hydraulic power. The rotation speed of the stirring shaft 5 is 1° per second, and it only rotates three times per hour, and it takes 6 minutes to rotate one circle. The power is disconnected for the rest of the time.

[0025] The diameter of the stirring shaft is 27.3 cm, the stirring blade is a long strip with a 1 / 4 circle at the top and parallel sides, the blade width of the stirring blade is 20 cm, and the centerline length of the stirring blade is 37.2% of the height of the horizontal anaerobic fermentation chamber.

[0026] The temperature and power coordinated control system includes an intelligent control system 20, which integrates a hydraulically driven plug-flow low-speed strong mixing and stirring system, a multi-material coordinated feeding system and an electric auxiliary heating component 21 for integrated control. The stirring time is controlled by setting parameters on the interface of the intelligent control system 20, and the temperature of the horizontal anaerobic fermentation bin and other key parameters of anaerobic fermentation are detected in real time by radar, and the feeding / discharging device is controlled in a coordinated manner, which is simple and convenient to operate.

[0027] Example 2 This embodiment provides a method for using the above-mentioned continuous high solid content anaerobic fermentation equipment, comprising the following steps: Step 1: During the initial fermentation, anaerobic sludge is added into the feed bin 13, and the delivery screw pump 12 is turned on to deliver the inoculum to the fermentation tank 6 until the volume of the inoculum in the fermentation tank 6 reaches 1 / 3 of the volume of the fermentation tank 6; Step 2: Heat the temperature of the fermentation box 6 to 35° C. through the electric auxiliary heating component 21; Step 3: Add 2m3 of 3 The high solid content multi-organic solid waste is treated by opening the water delivery pipe 16 to adjust the solid content to 18%, using the spiral stirring shaft 15 to stir it evenly, and then opening the delivery screw pump 12 to transport it to the fermentation box 6, and using the stirring shaft 5 of the hydraulically driven plug flow low-speed strong mixing and stirring system to stir it; Step 4: When the internal material of the fermentation box 6 reaches 2 / 3 of the box volume, the discharge motor is turned on to discharge the same volume of anaerobic fermentation residue from the discharge port 11 regularly according to the feed amount.

[0028] The continuous high solid content anaerobic fermentation equipment of the present invention is used to treat multiple high solid content organic wastes, such as Figure 3 and 4 It can be seen that the volumetric gas production rate is equivalent to that of dry anaerobic fermentation. After testing, the volumetric gas production rate of anaerobic fermentation can reach up to 2.1 m per day. 3 ·m -3 ; Depend on Figure 5 It can be seen that the use of the plug-flow stirring shaft 5 and the hydraulic drive method to stir the materials can effectively reduce the stirring dead zone.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A continuous high solid content anaerobic fermentation equipment, characterized in that: include: Multi-material coordinated feeding system, used to treat multi-organic solid waste with high solid content; A horizontal anaerobic fermentation chamber is connected to the multi-material coordinated feeding system through a conveying pipeline and is used to ferment the treated high-solid content multi-organic solid waste; A hydraulically driven plug-flow low-speed strong mixing and stirring system is arranged in the horizontal anaerobic fermentation chamber and is used to stir multi-organic solid waste with high solid content; The temperature and power coordinated control system drives the hydraulically driven plug-flow low-speed strong mixing and stirring system and the multi-material coordinated feeding system.

2. The continuous high solid content anaerobic fermentation equipment according to claim 1, characterized in that: The hydraulically driven plug-flow low-speed strong mixing stirring system includes a stirring shaft arranged in the fermentation box body, and stirring blades are evenly distributed on the stirring shaft. One end of the stirring shaft is connected to the stirring box body through a first bearing seat, and the other end passes through the fermentation box body and is connected to an external hydraulic driving device through a second bearing seat. The hydraulic driving device is connected to a hydraulic station.

3. The continuous high solid content anaerobic fermentation equipment according to claim 2, characterized in that: The axial spacing of each stirring blade on the stirring shaft is 50 cm, and there is only one single-sided stirring blade at each blade point on the stirring shaft. Each stirring blade is arranged in sequence with an axial stirring blade at an angle of 90° in a clockwise direction, and the plane of the stirring blade is distributed on the stirring shaft at an angle of 67° to the axial direction.

4. The continuous high solid content anaerobic fermentation equipment according to claim 3, characterized in that: The rotation speed of the stirring shaft is 1° per second, three revolutions per hour, and each revolution takes 6 minutes.

5. The continuous high solid content anaerobic fermentation equipment according to claim 4, characterized in that: The diameter of the stirring shaft is 27.3 cm, the stirring blade is a long strip with a 1 / 4 circle at the top and parallel sides, the blade width of the stirring blade is 20 cm, and the centerline length of the stirring blade is 37.2% of the height of the horizontal anaerobic fermentation bin.

6. The continuous high solid content anaerobic fermentation equipment according to claim 5, characterized in that: The horizontal anaerobic fermentation bin comprises a fermentation box body, an observation port and a biogas outlet are arranged on the top of the fermentation box body, and an electric auxiliary heating component and a radar liquid level detection device are arranged inside the fermentation box body.

7. The continuous high solid content anaerobic fermentation equipment according to claim 6, characterized in that: The multi-material collaborative feeding system includes a feeding bin, which is connected to an external water pipeline. A spiral stirring shaft is arranged in the feeding bin, the top of the spiral stirring shaft is connected to a motor output shaft, and a conveying screw pump is arranged at the bottom of the feeding bin.

8. The continuous high solid content anaerobic fermentation equipment according to claim 7, characterized in that: The temperature and power coordinated control system includes an intelligent control system, which integrates a hydraulically driven plug-flow low-speed strong mixing and stirring system, a multi-material coordinated feeding system and an electric auxiliary heating component.

9. A method for using the continuous high solid content anaerobic fermentation equipment according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: During the initial fermentation, anaerobic sludge is added into the feed bin, and the delivery screw pump is turned on to deliver the inoculum to the fermentation tank until the volume of the inoculum in the fermentation tank reaches 1 / 3 of the volume of the fermentation tank; Step 2: Heat the temperature of the fermentation box to 35±1°C or 55±1°C through the electric auxiliary heating component; Step 3: Add 1-2m3 of water into the feed bin every day 3 For high-solid content multi-organic solid waste, open the water pipeline to adjust the solid content to 15%-20%, use the spiral stirring shaft to stir it evenly, then turn on the delivery screw pump to transport it to the fermentation box, and use the stirring shaft of the hydraulically driven plug flow low-speed strong mixing and stirring system to stir it; Step 4: When the internal material of the fermentation box reaches 2 / 3 of the box volume, turn on the discharge motor and regularly output the same volume of anaerobic fermentation residue from the discharge port according to the feed amount.

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