Method and system for strengthening perishable garbage to form fertilizer by machine through low-temperature rotten return material
By pretreating perishable waste and mixing the low-temperature rotten material, using batch stirring, aeration and exhaust treatment, the addition of microbial agents and conditioning agents in machine composting is solved, the amount of microbial agents and conditioning agents is added, the difficulty in starting heating up, and the difference in moisture removal is solved. , The problem of low degree of malfunction has achieved efficient perishable garbage decomposition and low-cost organic fertilizer production.
Patent Information
- Application Number
- CN202411164601.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-23
- Publication Date
- 2025-01-17
AI Technical Summary
The existing machine composting technology has the problems of high cost of adding microbial bacteria and conditioning agents, difficulty in starting heating, poor moisture removal, and low degree of compost products, resulting in low processing efficiency and product quality not meeting standards.
By pretreating perishable garbage and mixing low-temperature rotten material, using two-stage treatment methods of batch-type full mixing, aeration, and air extraction and dehumidification, the rapid heating and efficient decomposition of perishable garbage is achieved, and a complete replacement of exogenous microbial bacteria and conditioning agent.
No additional bacterial agents and conditioning agents are required to quickly reduce the moisture content of perishable waste, increase the compost temperature and ripening degree, shorten the compost cycle, and the moisture content of the product complies with the "Organic Fertilizer" standards, and reduce operating costs.
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Figure CN119320290A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method and system for mechanically making fertilizer from low-temperature matured recycled materials and easily perishable garbage, which is applicable to the field of solid waste resource treatment. Background Art
[0002] At present, aerobic composting is an important means to achieve harmless treatment of perishable garbage and full resource utilization. Traditional static windrow composting has problems such as long composting cycle, large area, low disposal efficiency, and heavy odor pollution. It is gradually being replaced by machine composting technology. This is because machine composting equipment is equipped with auxiliary measures such as ventilation and aeration, stirring and turning, and exhaust dehumidification, which can accelerate the start of aerobic composting to a certain extent, promote moisture removal, and reduce the overflow of odorous gases, thereby improving the efficiency of aerobic composting of perishable garbage.
[0003] However, existing machine composting still has the following technical disadvantages, including:
[0004] 1) Microbial agents need to be added, which is costly: The microbial degradation function of perishable garbage raw materials is limited and the number of functional microorganisms is insufficient. Functional microbial agents need to be added to accelerate the degradation process of organic matter.
[0005] 2) It is necessary to add conditioners such as sawdust and corn cobs to reduce the processing capacity: The moisture content of perishable garbage raw materials is as high as 75% or more, and it is often necessary to add low-water conditioners to reduce the moisture content of compost raw materials and promote microbial growth and metabolism. In addition, adding conditioners can increase the porosity of compost raw materials and promote water removal. However, too much addition will affect the composting efficiency and product quality.
[0006] 3) It is difficult to start heating: exogenous microorganisms are not adapted to the high water content and high acidity habitat, and their growth, reproduction and metabolic functions are slow. It is difficult to raise the material temperature to 50°C, which takes at least 3 days, significantly affecting the high-temperature fermentation process of composting and prolonging the composting fermentation cycle.
[0007] 4) Poor moisture removal: Since the material temperature is blocked at the start, the effect of endogenous biological heat carrying water vapor and evaporating it is poor. It is difficult to reduce the moisture content of perishable garbage to below 55% within 1 to 2 days by relying solely on the exhaust and dehumidification components of the composting equipment to extract a small amount of moisture on the surface of the material and moisture in the bin. This also indirectly affects the moisture content of the compost product to 40%, or even below 30%.
[0008] 5) The maturity of compost products is poor: Limited by the theoretical design capacity of the equipment, the machine composting cycle is often about 15 days. However, the machine composting process on the market is limited by many factors such as difficulty in starting and heating, poor moisture removal, and inability to guarantee high-temperature composting time. The maturity of compost products is often less than 90%, or even less than 70%, and the moisture content is basically higher than 40%. The product quality does not meet the standard requirements of "Organic Fertilizer" (NY525-2021). Summary of the invention
[0009] The technical problem to be solved by the present invention is: in view of the above-mentioned existing problems, a method and system for strengthening the mechanical fertilizer production of perishable garbage by low-temperature composting recycled materials is provided.
[0010] The technical solution adopted by the present invention is: a method for mechanically making fertilizer from low-temperature mature recycled materials to strengthen perishable garbage, characterized by comprising:
[0011] Pre-treatment of perishable waste, including removal of impurities and dehydration;
[0012] The pre-treated perishable garbage is mixed with the low-temperature matured recycled material to form a mixed material;
[0013] The mixed material is subjected to the first stage of treatment, in which the mixed material to be treated is intermittently fully mixed, aerated and dehumidified by ventilation;
[0014] The mixed material is subjected to a second stage of treatment, in which ventilation and dehumidification are performed throughout the mixed material to be treated, and intermittent compost turning and aeration are performed at the same time.
[0015] The moisture content of the pretreated perishable garbage is between 70% and 72% and the particle size is less than 3 cm.
[0016] The low-temperature matured recycled material is the screened material after the low-temperature matured material is screened by a vibrating screen with an aperture of 2 cm.
[0017] The method of mixing the pretreated perishable garbage with the low-temperature matured recycled material to form a mixed material comprises:
[0018] The low-temperature matured recycled materials and the pre-treated perishable garbage are fully mixed in a ratio of 1:5. The mixing time is 5 minutes, and the pile height is controlled at 0.5-0.8m. No additional bacterial agents or conditioners are required.
[0019] The first stage includes:
[0020] In each intermittent cycle, aeration and dehumidification are operated in conjunction for 15 to 25 minutes. During the aeration process, full mixing and stirring are carried out for 5 to 8 minutes, and no full mixing, aeration and dehumidification are carried out for the remaining 35 to 45 minutes. After a 1-day startup heating stage, the temperature of the perishable garbage material rises to above 50°C and the moisture content is reduced to below 55%.
[0021] The second phase includes:
[0022] The residence time is 9 to 11 days, the frequency of turning the pile is 1 to 2 times per day, and the frequency of aeration is 15 to 35 minutes per hour, ensuring that the temperature of the internal material is maintained at 50 to 70°C for at least 6 to 8 days, and then the material automatically cools down to below 40°C until the material is decomposed, the moisture content of the decomposed material is 25% to 30%, and the germination index of plant seeds is greater than 70%.
[0023] A system for low-temperature matured recycled materials to strengthen the mechanical fertilizer production of perishable garbage, characterized by comprising:
[0024] Pretreatment equipment for pretreatment of perishable waste, including removal of impurities and dehydration;
[0025] Material mixing equipment, used to mix the pre-treated perishable garbage with the low-temperature matured recycled materials to form a mixed material;
[0026] The machine composting equipment is used for the first stage treatment of the mixed material to achieve rapid start-up and heating of the mixed material. In this stage, the mixed material to be treated is intermittently fully mixed, stirred, aerated and dehumidified by ventilation; and for the second stage treatment of the mixed material to achieve rapid maturation of the mixed material. In this stage, the mixed material to be treated is fully dehumidified by ventilation, and intermittent composting and aeration are performed at the same time.
[0027] Also includes:
[0028] A vibrating screen with an aperture of 2 cm is used to screen the low-temperature mature materials. The material on the screen is used as the low-temperature mature return material, and the material under the screen is a homogeneous fertilizer product.
[0029] The beneficial effects of the present invention are:
[0030] 1) No need to add microbial agents. Low-temperature matured recycled materials are rich in mesophilic functional microorganisms, among which the number of mesophilic bacteria is 10 7 ~10 8 CFU / g, the number of mesophilic fungi is 10 4 ~10 5 CFU / g, these functional microorganisms have experienced high-temperature composting environment, have extremely strong tolerance and reproduction ability, can completely replace exogenous microbial agents, and embody more advantageous reproduction, degradation and other metabolic functions and competitive advantages.
[0031] 2) No need to add sawdust, corncobs and other conditioning agents. The moisture content of the low-temperature mature recycled materials (particle size>2cm) after screening is about 25% to 30%. Compared with the easily perishable garbage, the compost raw materials mixed with the perishable garbage at a ratio of 1:5 have a moisture content of 5% to 8% lower and a porosity increase of 30% to 35%. Therefore, the low-temperature mature fertilizer used as recycled materials can completely replace sawdust, corncobs and other conditioning agents, reduce operating costs and improve treatment effects.
[0032] 3) Aerobic composting starts quickly, and it only takes 1 day to reach the high-temperature composting temperature (50°C). The microorganisms in the low-temperature mature recycled materials have strong tolerance and active degradation ability, which can quickly degrade the organic matter in the perishable garbage raw materials and generate bioheat, causing the composting temperature to rise to the high-temperature composting temperature within 1 day.
[0033] 4) Aerobic composting removes moisture quickly, and the moisture content of the material drops to below 55% within 1 day. The porosity of the compost material mixed with low-temperature mature recycled materials and perishable garbage increases, which is conducive to the convection of hot air and moisture, and promotes the removal of water vapor. At the same time, the degradation of organic matter also indirectly converts the bound water inside the substance into free-flowing water, which is transferred to the bottom of the system in the form of leachate and then discharged. In summary, the moisture content of the composting system drops rapidly to below 55% after about 1 day. After a composting cycle of 12 to 15 days, the moisture content of the product is about 25% to 30%, which meets or even exceeds the requirements of the "Organic Fertilizer" (NY525-2021) standard.
[0034] 5) The compost product has uniform texture and high degree of maturity: Compared with other machine composting processes, the material startup temperature rise and moisture removal time of this process are faster, thereby extending the high-temperature composting time of the material and shortening the composting cycle. The perishable garbage can be quickly converted into low-moisture (25%-30%) and highly mature fertilizer within 12-15 days. The relevant indicators are better than the "Organic Fertilizer" (NT525-2021) standard requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 A flowchart of an embodiment. DETAILED DESCRIPTION
[0036] Embodiment 1: This embodiment is a method for mechanically composting perishable garbage by using low-temperature matured recycled materials, which specifically includes the following steps:
[0037] S1. Pre-treat the perishable waste, including removing impurities and dehydrating.
[0038] S11. The perishable garbage collection and transportation vehicle dumps the collected perishable garbage into the perishable garbage collection pool. After manual sorting to remove plastics, glass, metal, fabrics and large pieces of difficult-to-degrade debris, the perishable garbage is transferred to the spiral extrusion dehydration system.
[0039] S12, after the perishable garbage was dehydrated twice by screw extrusion at a pressure of 0.5Mpa, the moisture content of the perishable garbage was reduced to 70.24% to 71.55%, and the particle size was less than 3cm. The number of microorganisms in the material to be treated was determined to be about 10 3 ~10 4 CFU / g.
[0040] S2. Mix the pre-treated perishable garbage with the low-temperature matured recycled material to form a mixed material.
[0041] S21. Use the discharging screw mechanism to transfer the original low-temperature mature materials in the machine composting equipment to a vibrating screen with a pore size of 2 cm for vibration screening, and obtain the screened material as the return material for machine composting. The moisture content of the low-temperature mature return material is tested to be 26.72% to 29.53%, the material temperature is about 37.5°C, and the number of microorganisms is about 10 6 CFU / g. The sieved material is a decomposed fertilizer with uniform particle size, and the plant seed germination index is 108.12% to 112.81%. Other indicators also meet the standard requirements of "Organic Fertilizer" (NY525-2021), and are bagged and packaged for shipment.
[0042] S22, the recycled materials obtained after screening and the pre-treated perishable garbage are fed in a ratio of 1:5, and are fully mixed at the front end of the mechanical composting reaction. The mixing time is 5 minutes, and the pile height is about 0.6-0.7m. The moisture content of the mixed material is about 62.80%-65.02%, the material temperature is about 30.2℃, and the number of microorganisms is about 10 5 CFU / g, meeting the microbial quantity requirement for rapid start-up of aerobic composting.
[0043] S3, the mixed material is subjected to the first stage of treatment, in which the mixed material to be treated is subjected to intermittent full mixing, aeration and dehumidification by ventilation.
[0044] The fully mixed materials are treated at the front end of the machine composting equipment for a 1-day startup heating stage (first stage treatment), during which the materials to be treated are intermittently fully mixed, aerated, and dehumidified.
[0045] In each intermittent cycle, aeration and dehumidification are operated in conjunction for 20 minutes. During the aeration process, full mixing and stirring are carried out for 5 minutes. No stirring, aeration and dehumidification are carried out for the remaining 40 minutes. The purpose of intermittent stirring, aeration and dehumidification is to maintain the temperature of the pile and avoid the degradation of microorganisms caused by excessive heat dissipation.
[0046] The purpose of aeration and dehumidification is to enhance convection and quickly remove moisture from the surface of the material and water vapor inside. The auxiliary effect of stirring also accelerates the above effect. After 1 day of start-up and heating stage, the temperature of the perishable garbage material rose to 52°C, the moisture content dropped to below 55%, and the number of microorganisms reached 10 6 ~10 7 CFU / g.
[0047] S4. The mixed material is subjected to the second stage of treatment, in which the mixed material to be treated is subjected to ventilation and dehumidification throughout the whole process, and intermittent compost turning and aeration are performed at the same time.
[0048] After 1 day of start-up heating stage treatment, the moisture content, temperature and number of microorganisms of the perishable garbage all reach the theoretical conditions for entering high-temperature composting. Next, it will undergo a progressive high-temperature maturity stage treatment lasting 9 to 11 days (second stage treatment). In this stage, the materials to be treated are subjected to exhaust dehumidification throughout the process, and intermittent compost turning and aeration are carried out. The frequency of compost turning is once a day, and the frequency of aeration is 15 minutes / hour.
[0049] Due to the high temperature composting process, the composting materials continue to emit water vapor and malodorous gases. The whole process of exhaust dehumidification helps to remove the water vapor and malodorous gases in the bin. For the relatively small frequency of turning the compost (1 time / day), on the one hand, it is to ensure the reasonable travel distance of the materials, and on the other hand, it is to regulate the high temperature environment of the compost body to ensure that the material temperature is maintained at 50-70℃ for at least 6 days. As the composting enters the end, the material temperature will automatically drop below 40℃ until the material is low-temperature decomposed.
[0050] In this embodiment, a discharging screw can be used to transfer the low-temperature mature materials in the machine composting equipment to the vibrating screen to perform step S21.
[0051] The following is an explanation with two groups of comparative experiments, wherein the first group of comparative experiments differs from the aforementioned process of this embodiment in that the 1-day startup temperature rise stage is not set, and the recycled material is directly subjected to the progressive high-temperature composting stage after being mixed with the material, and the rest of the practices are consistent with the present embodiment; the second group of comparative experiments differs from the aforementioned process of this embodiment in that the recycled material is not mixed, and the perishable garbage is directly subjected to machine composting operation after manual sorting and spiral extrusion dehydration, and the rest of the practices are consistent with the present embodiment.
[0052] Finally, in the first group of comparative experiments, since the composting startup process after feeding was not fully mixed and stirred at an appropriate frequency, only aeration and once-a-day turning operations were performed, the air convection of the material was weak, the ability of microorganisms to degrade organic matter was weak, and the material startup temperature rise effect was not good. In addition, continuous ventilation and dehumidification also led to significant heat dissipation of the pile. The material temperature was maintained at 28-30℃ for about 3 days before the material temperature showed an upward trend. The residence time of the entire composting cycle was as high as 20 days before the material was fully composted.
[0053] In the second group of comparative experiments, due to the lack of supplementation of an appropriate amount of mature recycled materials, the number of mesophilic microorganisms in the composting materials was insufficient, the moisture content of the materials was high, and the porosity was low, resulting in difficulty in achieving a good dehydration effect during the 1-day startup heating stage. The moisture content of the materials after the startup heating stage was 68.54% to 70.82%, and the startup heating effect was not achieved. Moreover, due to the excessively high moisture content of the materials, the subsequent progressive composting process The compost turning machine was unable to successfully turn the materials, and the composting failed.
[0054] From the above, it can be seen that the low-temperature composting recycling material intensified perishable garbage machine fertilizer-making process in this embodiment can quickly convert perishable garbage into decomposed organic fertilizer, avoid the use of large amounts of microbial agents and conditioners such as sawdust and corn cobs, greatly reduce resource and economic waste, and effectively solve the problems of large amounts of microbial agents and conditioners added in the process of perishable garbage fertilizerization, difficulty in starting and heating, poor moisture removal, and poor maturity of compost products.
[0055] Example 2: This example is a system for low-temperature composting recycled materials to enhance the mechanical fertilizer production of perishable garbage, which can be used to implement the method in Example 1, including pretreatment equipment, a vibrating screen (with an aperture of 2 cm), material mixing equipment and progressive machine composting equipment, etc.
[0056] In this example, the pretreatment equipment is used to pretreat the perishable garbage, including removing impurities and dehydrating; the vibrating screen is used to screen the low-temperature mature materials, and the screened materials are used as warm-composted return materials; the material mixing equipment is used to mix the pretreated perishable garbage with the low-temperature mature return materials to form a mixed material.
[0057] In this embodiment, the machine composting equipment is used to carry out the first stage treatment of the mixed material, in which the mixed material to be treated is intermittently fully mixed, stirred, aerated and dehumidified by ventilation; and is used to carry out the second stage treatment of the mixed material, in which the mixed material to be treated is fully dehumidified by ventilation, and intermittent compost turning and aeration are carried out at the same time.
[0058] In this example, the front end of the progressive machine composting equipment is equipped with a fully mixed spiral stirring shaft, which can not only fully stir and mix the materials, but also realize the progressive processing of the materials; the middle and rear ends of the equipment are equipped with chain-plate compost turners, which can not only regularly turn the materials, but also realize the progressive translation of the materials; the bottom of the entire equipment is laid with aeration pipelines, and exhaust and dehumidification equipment is set on the top.
Claims
1. A method for strengthening the mechanical fertilizer production of perishable garbage by using low-temperature mature recycled materials, characterized in that: include: Pre-treatment of perishable waste, including removal of impurities and dehydration; The pre-treated perishable garbage is mixed with the low-temperature matured recycled material to form a mixed material; The mixed material is treated in the first stage, in which the mixed material to be treated is intermittently fully mixed, aerated and dehumidified by ventilation; The mixed material is subjected to a second stage of treatment, in which ventilation and dehumidification are performed throughout the mixed material to be treated, and intermittent compost turning and aeration are performed at the same time.
2. The method for strengthening the mechanical fertilizer production of perishable garbage by using low-temperature mature recycled materials according to claim 1, characterized in that: The moisture content of the pretreated perishable garbage is between 70% and 72% and the particle size is less than 3 cm.
3. The method for strengthening the mechanical fertilizer production of perishable garbage by using low-temperature mature recycled materials according to claim 1, characterized in that: The low-temperature matured recycled material is the screened material after the low-temperature matured material is screened by a vibrating screen with an aperture of 2 cm.
4. The method for strengthening the mechanical fertilizer production of perishable garbage by using low-temperature mature recycled materials according to claim 1 or 3, characterized in that: The method of mixing the pretreated perishable garbage with the low-temperature matured recycled material to form a mixed material comprises: The low-temperature matured recycled materials and the pre-treated perishable garbage are fully mixed in a ratio of 1:
5. The mixing time is 5 minutes and the pile height is controlled at 0.5-0.8m.
5. The method for strengthening the mechanical fertilizer production of perishable garbage by using low-temperature mature recycled materials according to claim 1, characterized in that: The first stage includes: In each intermittent cycle, aeration and exhaust dehumidification are operated in conjunction for 15 to 25 minutes. During the aeration process, full mixing and stirring are carried out simultaneously for 5 to 8 minutes. In the remaining 35 to 45 minutes, full mixing and stirring, aeration and exhaust dehumidification are not carried out.
6. The method for strengthening the mechanical fertilizer production of perishable garbage by using low-temperature mature recycled materials according to claim 1, characterized in that: The second phase includes: The frequency of turning the pile is 1 to 2 times per day, and the frequency of aeration is 15 to 35 minutes per hour, to ensure that the temperature of the internal material is maintained at 50 to 70°C for at least 6 to 8 days, and then the material automatically cools down to below 40°C until the material is mature.
7. A system for low-temperature matured recycled materials to strengthen the mechanical fertilizer production of perishable garbage, characterized in that: include: Pretreatment equipment for pretreatment of perishable waste, including removal of impurities and dehydration; Material mixing equipment, used to mix the pre-treated perishable garbage with the low-temperature matured recycled materials to form a mixed material; The machine composting equipment is used for the first stage treatment of the mixed material to achieve rapid start-up and heating of the mixed material. In this stage, the mixed material to be treated is intermittently fully mixed, stirred, aerated and dehumidified by ventilation; and for the second stage treatment of the mixed material to achieve rapid maturation of the mixed material. In this stage, the mixed material to be treated is fully dehumidified by ventilation, and intermittent composting and aeration are performed at the same time.
8. The system for strengthening the mechanical fertilizer production of perishable garbage by using low-temperature mature recycled materials according to claim 7 is characterized in that: Also includes: A vibrating screen with an aperture of 2 cm is used to screen the low-temperature mature materials. The material on the screen is used as the low-temperature mature return material, and the material under the screen is a homogeneous fertilizer product.