Efficient drying technology of biomass waste and urban life sludge by neutralization and stirring

Abstract

The application discloses a biomass waste and urban domestic manure stirring efficient drying technology and system, and particularly relates to the technical field of solid waste treatment and resource utilization, and realizes rapid drying to a water content of less than or equal to 15% in 3-7 days through a phased ventilation and turning strategy, namely high-intensity ventilation + high-frequency turning in the first 24 hours, low-speed ventilation + moderate turning in the later period, in combination with a gradient-aperture porous bottom plate and a wave-shaped stainless steel turning blade (R angle 0.5 mm, inclination angle 45°±10°), and the energy consumption is reduced by 65% compared with a traditional process. The system is integrated with an online water content sensor and ozone cooperative treatment, the hydrogen sulfide concentration is less than or equal to 5 ppm, ammonia nitrogen emission is reduced by 80%, and is suitable for multiple scenes of municipal and breeding farms. The dried material is prepared into biomass fuel particles with a bulk density of greater than or equal to 650 kg / m 3 by ring die granulation (compression ratio 6:1-8:1), the calorific value reaches 14-16 MJ / kg, and high-value utilization is realized. 3

Description

Technical Field

[0001] The technical field of this invention is solid waste treatment and resource utilization technology, specifically involving efficient drying technology for neutralizing, mixing and drying biomass waste and urban domestic sewage sludge. Background Technology

[0002] The large-scale treatment of urban sewage and excrement is one of the core challenges of modern urban environmental governance. This type of waste has a complex composition, with an initial moisture content generally ranging from 70% to 85%, and its colloidal texture results in extremely high resistance to dehydration. If direct landfill disposal is used, the COD (chemical oxygen demand) concentration in the leachate can reach as high as 20,000-50,000 mg / L, exceeding the pollution control standard limit for landfills by more than 100 times, posing a long-term threat of seepage to groundwater sources. While natural composting can achieve partial resource recovery, the complete fermentation cycle typically requires 15-25 days, and the concentrations of odorous substances such as hydrogen sulfide and ammonia released during the process exceed the limits of the "Odor Pollutant Emission Standard" by 3-8 times, severely restricting its application and promotion in densely populated areas.

[0003] Traditional mechanical thermal drying technologies attempt to accelerate dehydration through external energy input, such as drum dryers or belt dryers. However, evaporating one ton of water requires 600-800 kWh of electricity or equivalent steam, resulting in processing costs as high as 120-180 yuan per ton. More importantly, high-temperature drying easily causes thermal denaturation of organic matter in the manure residue—when the temperature exceeds 80°C, proteins coagulate to form a dense, hard shell, blocking internal moisture migration channels. The final product still retains 25%-30% moisture content, failing to meet the baseline requirements for subsequent resource utilization.

[0004] In the field of biomass-assisted drying, existing technologies have revealed three structural defects:

[0005] Firstly, the compatibility of auxiliary materials is insufficient. When improperly crushed straw (particle size > 10mm) or sawdust (containing more than 15% miscellaneous wood chips) is mixed with manure residue, stratification occurs due to differences in density and water absorption rate. Actual measurement data shows that the porosity of the upper layer of biomass in the mixture can reach 45%-60%, while that of the lower manure residue layer is only 5%-10%. The ventilation airflow preferentially passes through the high-porosity area, creating a "short-circuit effect," which causes the overall dewatering efficiency to decrease by 30%-40%.

[0006] Secondly, the turning and turning strategy is overly mechanized but lacks intelligence. Fixed-frequency turning (e.g., twice daily throughout the process) is severely disconnected from the changing moisture content of the material: in the initial high-moisture stage (>60%), insufficient turning frequency leads to the formation of adhesive extracellular polymeric substances (EPS) produced by microbial aerobic metabolism, causing the material to clump together, with the permeability coefficient of the clump layer dropping as low as 10. -6cm / s; if high-intensity turning and tumbling is maintained even after the moisture content drops below 30%, it will cause the concentration of particulate matter (PM10) to exceed the standard, with the measured dust emission in the working environment reaching 8-12 mg / m³. 3 It exceeds twice the "Occupational Exposure Limits for Hazardous Factors in the Workplace".

[0007] Third, structural defects in the equipment restrict energy efficiency conversion. When conventional trough-type compost turners operate in viscous manure sludge, the accumulated thickness of the adhering material on the blade surface can reach 3-5 cm, significantly increasing power loss—requiring an additional 15%-20% increase in motor power for the same processing capacity. More seriously, the shearing force generated by the perpendicular impact of the blades with the material can damage the biomass fiber skeleton, causing the pore structure of the mixture to collapse and increasing ventilation resistance by more than 50%.

[0008] The current system's lagging regulation further amplifies operational risks. The proportion of biomass additives is largely adjusted manually based on experience, but the viscosity and salt content of manure residue from different sources fluctuate significantly (e.g., restaurant manure residue has an oil content of 8%-12%, and community septic tank manure residue has a gravel content >5%). Without a real-time moisture content feedback mechanism, the additive addition error rate is as high as ±20%, and the final product moisture content varies greatly (the difference between the maximum and minimum values) by more than 12 percentage points, directly hindering large-scale granulation applications—materials with a moisture content >18% experience insufficient lubrication during ring die extrusion, leading to a die blockage rate as high as 30%, and increasing the frequency of production line shutdowns for cleaning by 2-3 times per day.

[0009] The aforementioned technical bottlenecks all point to a common industry need: how to achieve efficient dehydration of fecal residue and excrement under zero external heating conditions, while ensuring that the physical properties of the product meet the industrial-grade standards for resource utilization and avoiding the risk of secondary pollution. Summary of the Invention

[0010] To overcome the shortcomings of existing technologies, the present invention aims to provide a highly efficient drying technology for neutralizing, mixing, and drying biomass waste with urban domestic sewage sludge and feces.

[0011] A highly efficient drying technology for mixing biomass waste with urban sewage sludge and excrement comprises the following steps:

[0012] (a) Mix manure residue with a moisture content of 70-85% with biomass additives at a dry basis mass ratio of 1:(0.8-1.2) for 30-60 minutes;

[0013] (b) Place the mixture in a ventilation trough and turn it over at a frequency of ≥3 times / day and a depth of 50±5cm for the first 24 hours, while the bottom ventilation speed is 1.0-1.2m / s;

[0014] (c) After 24 hours, continue to treat the material by turning it over ≥ 2 times / day and by ventilation speed of 0.5-0.8m / s. When the ambient humidity is ≤ 60%, treat for 2-4 days and when the ambient humidity is > 60%, treat for 4-6 days until the moisture content of the material is ≤ 15%.

[0015] Biomass adjuvants (dry basis mass ratio 1:0.8-1.2) form a porous adsorption framework, whose capillary force promotes moisture migration in the manure residue; a mixing time of 30-60 minutes ensures uniform dispersion of the material, increasing the specific surface area by 3 times (BET test) and accelerating moisture evaporation. Through precise proportioning of biomass adjuvants and manure residue, moisture content gradient control is achieved, shortening the drying cycle by more than 40%.

[0016] Furthermore, the biomass adjuvant is selected from at least one of sawdust, rice husks, or straw fragments, wherein: the sawdust particle size is 0.5-3 mm and the moisture content is <12%; the rice husk crushed particle size is <5 mm; and the straw fragments crushed particle size is <8 mm. Sawdust (0.5-3 mm) forms a microporous network with a permeability of 0.01 Darcy (calculated using Darcy's law); the high porosity (65%) of rice husks (crushed particle size <5 mm) provides airflow channels, reducing the resistance coefficient by 40%; and the fibrous structure of straw fragments (<8 mm) enhances the material's bulkiness, reducing the risk of caking. Controlling the particle size of the biomass adjuvant improves air permeability and reduces energy consumption by 65%.

[0017] Furthermore, in steps (b) and (c), the turning and turning operation is carried out using a trough-type turning and turning machine. The blades of this machine have a wavy cutting edge with a radius of 0.5 mm and an installation angle of 45°±10°. The blades are made of stainless steel with a hardness ≥ HRC50. The wavy cutting edge (0.5 mm radius) generates shear stress concentration, reducing material crushing energy consumption by 25% (ANSYS simulation); the 45°±10° installation angle increases the blade cutting depth by 30%, raising the material turning rate to 92%; the stainless steel material (hardness ≥ HRC50) is corrosion and wear resistant, extending its service life to 5000 hours. The wavy cutting edge turning and turning blades improve material crushing efficiency, achieving a screening rate of 95%.

[0018] A highly efficient drying system for mixing biomass waste with urban sewage sludge and excrement includes:

[0019] (1) A mixing chamber equipped with an online moisture content sensor;

[0020] (2) Trench-type compost turner with a span of 6-12m;

[0021] (3) Ventilation unit, the ventilation drying trough includes a porous bottom plate with an opening ratio of 30±5% and an axial flow fan group;

[0022] (4) Control unit, the control center is configured as follows:

[0023] When the moisture content sensor reading is >55%, increase the amount of biomass additive to a dry basis mass ratio of 1:1.2;

[0024] When the moisture content sensor reading is <45%, reduce the amount of biomass additives to a dry basis mass ratio of 1:0.8.

[0025] A moisture content sensor (accuracy ±0.5%) monitors the moisture content in real time, triggering dynamic proportioning of biomass additives; the control algorithm (BP neural network model) has a response time of <30 seconds and a deviation of ≤±1.2% (ISO13849 certified); the amount of biomass additives added is adjusted (1:0.8-1.2) to maintain the C / N ratio of the mixture at 25-30, optimizing microbial activity. An online moisture content feedback system improves treatment stability and adapts to manure residue from different sources.

[0026] Furthermore, the porous substrate has the following pore size distribution: 60±5% for 0.5-1mm pores and 40±5% for 1-2mm pores. The 60% proportion of 0.5-1mm pores (30% open area) forms micro-airflow channels, keeping the Reynolds number below 2000 (laminar flow); the 40% proportion of 1-2mm pores balances resistance, achieving an airflow uniformity of 95% (anemometer test); the porous substrate works synergistically with the biomass skeleton, reducing the pressure loss coefficient from 0.8 to 0.3. The gradient pore size substrate achieves uniform airflow distribution, reducing fan energy consumption by 62%.

[0027] Furthermore, the ventilation unit is connected to an ozone generator, with the ozone output concentration controlled at 0.1-0.3 ppm. 0.1-0.3 ppm ozone (half-life 20 minutes) oxidizes and decomposes thiols (reaction formula: RSH + O3 → RSO3H); ozone inhibits the activity of odor-producing bacteria (such as alkaloid-producing bacteria), reducing the total bacterial count by 7 orders of magnitude (plate count method); the ventilation system carries ozone through the material layer, increasing the mass transfer coefficient by 50% (double-film theory). Ozone synergistic treatment reduces ammonia nitrogen emissions by 80%, with odor concentration <2000 UO / m³. 3 .

[0028] A highly efficient dried material produced by mixing biomass waste with urban sewage sludge is characterized by a moisture content ≤15%; after being treated for 3 minutes by a vibrating screen with an amplitude of 1mm and a frequency of 50Hz, the sieve passing rate on a 3mm standard sieve is ≥95%. The vibrating screen treatment (1mm amplitude, 50Hz frequency) utilizes the resonance principle to separate agglomerates; the sieve passing rate on the 3mm standard sieve ≥95% indicates excellent particle dispersibility, with a bulk density of 0.65g / cm³. 3 A moisture content of ≤15% reduces the material's plasticity index to 8-12, making it suitable for ring die extrusion molding. The dried material exhibits improved particle size uniformity, achieving a granulation rate of 92%.

[0029] A method for preparing biomass fuel involves mixing biomass waste with urban sewage sludge and excrement using a high-efficiency drying technology to obtain dried material, which is then granulated by ring die extrusion. The ring die compression ratio is 6:1-8:1, and the forming temperature is 80±5℃. The compression ratio of 6:1-8:1 reduces the particle density of the material from 0.65 g / cm³. 3 Increased to 1.1 g / cm³ 3 (True density meter); Molding temperature 80±5℃ promotes lignin softening and bonding, particle durability index ≥98% (GB / T18719); Particle size Φ8-10mm balances combustion efficiency and transport performance, combustion rate reaches 0.12g / s (oxygen bomb calorimeter). Optimized ring die granulation parameters, fuel calorific value reaches 18MJ / kg.

[0030] An efficient drying system for mixing biomass waste with municipal sewage sludge is applied in a municipal sewage sludge treatment plant. The processing tank has a single tank length ≥30m, a width matching the span of the compost turner, and a tank depth of 1.2-1.5m. The 1.2-1.5m tank depth balances material thickness and air permeability, achieving an oxygen transfer rate of 0.15kg / (m³). 3 •h); trough length ≥30m extends the residence time to 3-7 days to meet drying requirements under different climatic conditions; the turning machine span 6-12m matches the trough width, achieving an operating efficiency of 150m³ / h. 2 / h (GPS positioning monitoring). The treatment tank design increases the single-unit processing capacity, with a daily processing capacity of up to 200 tons per tank.

[0031] A type of biomass fuel pellet, with a pellet diameter of Φ8-10mm and a bulk density ≥650kg / m³. 3 Bulk density ≥ 650 kg / m³ 3 (Measuring cylinder method) improves transportation economy, with a calorific value of 11.7 GJ / m³. 3 The particle size of Φ8-10mm results in a combustion surface area of ​​0.025m². 2 / g, burnout time shortened to 15 minutes; ash content ≤5% (GB / T28731) reduces boiler slagging risk, sulfur content <0.1% (compliant with EU EN14961 standard). Biomass fuel pellets have excellent performance and meet industrial fuel standards.

[0032] Beneficial effects of the present invention

[0033] 1. Significantly shortens the drying cycle and improves processing efficiency. A phased ventilation and dynamic turning strategy is adopted. For the first 24 hours, high-intensity ventilation (1.0-1.2 m / s) combined with high-frequency turning (≥3 times / day) rapidly removes surface moisture. Later, low-speed ventilation (0.5-0.8 m / s) and moderate turning (≥2 times / day) promote internal moisture migration, shortening the total drying time to 3-7 days. This represents an efficiency improvement of over 40% compared to traditional natural composting (10-15 days), making it suitable for large-scale continuous production needs.

[0034] 2. Significantly reduced energy consumption and outstanding economic efficiency. By constructing a porous structure using biomass additives (sawdust, rice husks, and straw fragments), the distribution of ventilation resistance is optimized. Combined with a porous bottom plate with gradient pore sizes (0.5-2mm), the air volume utilization rate is increased by more than 30%, and the overall energy consumption is reduced by 65% ​​compared to thermal drying. The power consumption per ton of material is controlled within 200kWh, significantly reducing operating costs.

[0035] 3. High uniformity of dried materials, facilitating subsequent utilization. The wavy-edged threshing blade (R angle 0.5mm, tilt angle 45°±10°) effectively reduces adhesion, and the stainless steel material (hardness ≥HRC50) ensures long-term stable operation, improving the looseness of materials. The final product has a moisture content ≤15%, and after being processed by a vibrating screen (50Hz, 3min), the 3mm sieve passing rate is ≥95%, which can directly meet the particle size requirements for granulation or incineration.

[0036] 4. Significantly reduced odor emissions and obvious environmental advantages. The ozone generator (0.1-0.3ppm) works in synergy with the ventilation system to oxidize and decompose sulfides and ammonia, reducing the concentration of hydrogen sulfide in the odor to below 5ppm and reducing ammonia nitrogen emissions by 80%. The working environment meets the limits of the "Odor Pollutant Emission Standard" (GB14554-93).

[0037] 5. The system is highly adaptable and widely applicable. Based on the dynamic feedback mechanism of the online moisture content sensor, the proportion of biomass additives can be adjusted in real time (adjustment rate ±0.05 / h), which can adapt to manure residue from different sources (moisture content fluctuating from 70-85%). The output material moisture content stability (±2%) is 50% higher than that of manual control, making it suitable for various scenarios such as municipal and livestock farms.

[0038] 6. The resource-based products have excellent performance and high market value. After ring die granulation (compression ratio 6:1-8:1, 80±5℃), the bulk density of the dried material (Φ8-10mm) is ≥650kg / m³. 3 With a calorific value of 14-16 MJ / kg, it meets the technical requirements of "Biomass Solid Molding Fuel" (GB / T21923-2008) and can be used directly as an alternative fuel or soil conditioner, increasing economic added value by more than 30%. Attached Figure Description

[0039] Figure 1 A schematic diagram of the overall layout of a high-efficiency drying system for mixing biomass waste and urban sewage.

[0040] In the diagram, 101: mixing and stirring chamber, 201: ventilated drying tank, 301: trough-type turning machine, 401: control center.

[0041] Figure 2 This is a schematic diagram of the blade structure of a turner.

[0042] Figure 3 This is a perspective view of the porous base plate structure.

[0043] Figure 4 This is the logic block diagram of the control unit. Detailed Implementation

[0044] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0045] Example 1

[0046] In mixing chamber 101, municipal sewage sludge with a moisture content of 77.5% is mixed with pine sawdust at a dry weight ratio of 1:1. The sawdust used is precision sieved, with a particle size controlled within the range of 1.2 to 2.8 mm and an average moisture content maintained at 9.8%. The mixing process lasts for 50 minutes to ensure material uniformity.

[0047] The mixed material is transferred via conveyor belt to a ventilated drying trough 201, which is 32 meters long, 8 meters wide, and 1.35 meters deep. The trough-type compost turner 301 then begins operation. Its specially designed wavy blades are made of 420 stainless steel with a hardness of HRC53, and the blade radius is precisely controlled at 0.5 mm. The installation tilt angle is set at 43 degrees. During the first 24 hours of drying, the system maintains a bottom ventilation velocity of 1.15 meters per second, with a turning frequency of once every 6 hours, and the turning depth strictly controlled within the range of 48 to 52 centimeters.

[0048] The control center 401 monitors environmental parameters in real time. When the detected ambient humidity reaches 58%, it automatically adjusts the operating parameters: reducing the ventilation speed to 0.65 meters per second and adjusting the turning frequency to once every 12 hours. Simultaneously, the ozone generator is activated to maintain an ozone flow concentration of 0.18 ppm. After a complete 96-hour drying cycle, sampling tests showed that the average moisture content of the material was 13.5%, and a standard vibrating sieve test showed that the 3 mm particle size passing rate reached 97.3%.

[0049] The final product was fed into a ring die pellet mill with a compression ratio of 7.5:1. The surface temperature at the discharge port was monitored using an infrared thermometer and found to be 83.2 degrees Celsius. The obtained biomass fuel pellets had a diameter of 9.2 mm, a bulk density of 663 kg / m³, and a lower heating value of 15.1 MJ / kg. The average energy consumption for the entire process was 188 kWh per ton of material, and the ammonia nitrogen concentration in the exhaust gas was 7.8 mg / m³, with a hydrogen sulfide content of 4.3 ppm.

[0050] Example 2

[0051] In mixing chamber 101, manure residue with an initial moisture content of 79.2% is mixed with crushed rice husks at a dry basis mass ratio of 1:0.95. The rice husks used have undergone professional crushing treatment, with a particle size distribution between 3.2 and 4.7 mm and an average moisture content of 8.5%. The mixing process lasts for 55 minutes to ensure thorough and uniform mixing.

[0052] The material is conveyed to a ventilated drying trough 201 for processing. This drying trough is 30 meters long, 10 meters wide, and 1.4 meters deep. The blades of the trough-type compost turner 301 are installed at an angle of 47 degrees, and the turning depth is controlled within the range of 49 to 51 centimeters. The control center 401 maintains the ozone concentration at 0.22 ppm based on real-time monitoring data.

[0053] Under ambient humidity of 65%, the system operated at a ventilation speed of 1.1 m / s for the first 24 hours, with 5 turning operations per day; afterwards, the ventilation speed was adjusted to 0.6 m / s, with 2 turning operations per day. After 112 hours of drying, the final product had a moisture content of 14.3% and a 3 mm sieve pass rate of 96.1%. The bulk density of the granulated product was 657 kg / m³, and the calorific value reached 15.6 MJ / kg.

[0054] Example 3

[0055] In this embodiment, corn stalk fragments are used as an auxiliary material, with a particle size controlled between 5 and 7.5 mm and an average moisture content of 10.3%. In the mixing chamber 101, the initial dry weight ratio of manure residue to straw is set at 1:1.1. When the intelligent adjustment system of the control center 401 detects that the material moisture content has dropped to 47%, it automatically adjusts the auxiliary material ratio to 1:0.8 at a rate of 0.05 per hour.

[0056] The depth of the ventilated drying trough 201 is set to 1.45 meters, and processing is carried out under an ambient humidity of 72%. The blade hardness of the trough-type turning and turning machine 301 is HRC50, and the turning and turning depth is controlled at 52 cm. After a complete drying cycle of 144 hours, the final product has a moisture content of 14.8%, a sieve pass rate of 95.4%, and a pellet formation rate of 93.7%.

[0057] Comparative Example 1

[0058] The system did not utilize the dynamic adjustment function of the control center 401, maintaining a fixed dry basis mass ratio of 1:1 for manure residue and auxiliary materials. The results showed extremely uneven distribution of material moisture content, with some areas reaching as high as 22.7%. The overall screening rate was only 81.5%, and the granulation rate decreased to 74.3%.

[0059] Comparative Example 2

[0060] A single ventilation mode was used, maintaining a wind speed of 0.8 meters per second throughout the process, with a fixed turning frequency of 3 times per day. During the processing, severe caking occurred on the surface of the material, and complete drying required 216 hours, which is 125% longer than in Example 1, and the unit energy consumption increased to 325 kWh per ton.

[0061] Comparative Example 3

[0062] The trough-type compost turner 301 uses traditional flat-blade blades with a blade radius of 2 mm. The results showed that the blades adhered severely during operation, requiring the machine to be stopped for cleaning every 3 to 4 hours. The final product had a screening rate of only 87.6% and uneven particle size distribution.

[0063] See the schematic diagram of the overall layout of the high-efficiency drying system for mixing biomass waste and urban sewage sludge. Figure 1 A schematic diagram of the blade structure of the turning machine can be found here. Figure 2 Perspective view of the porous base plate structure is shown below. Figure 3 The logic block diagram of the control unit is shown below. Figure 4 .

[0064] Table 1: Comparison and Analysis of Technical Effects

[0065]

[0066] Table 2: Comparison of Key Performance Improvements

[0067]

[0068] Note:

[0069] 1. The reference values ​​for traditional processes are taken from the average value of industry survey data.

[0070] 2. The calculation basis for the improvement is (traditional value - value of this invention) / traditional value × 100%.

[0071] 3. All data are from production tests of the same scale (30 tons / batch).

[0072] 4. The test environment temperature is 25±3℃ and the relative humidity is 60±5%.

[0073] The dynamic adjustment system of this invention effectively solves the problem of uneven material drying in traditional technologies. The coefficient of variation for moisture content in Comparative Example 1 reached 28.7%, while the coefficient of variation in this embodiment was controlled within 9.5%. Furthermore, the specially designed wavy-blade tumbling blade extends the continuous operating time of the equipment from 4 hours in Comparative Example 3 to over 72 hours, significantly improving production efficiency.

[0074] In terms of environmental indicators, the odor control effect of the embodiment was significant, with an average ammonia nitrogen emission concentration of 8.1 mg / m³. 3 Compared to traditional processes, emissions are reduced by 76.5%; hydrogen sulfide concentration is controlled below 5 ppm, fully meeting the emission standards of GB14554-93. The final biomass fuel pellets meet all technical requirements of GB / T21923-2008, giving them a significant competitive advantage in the market.

[0075] Matters not covered in this invention are common knowledge.

[0076] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A drying system employing a high-efficiency drying technology that mixes biomass waste with urban sewage sludge, characterized in that, The drying technology includes the following steps in sequence: (a) Mix manure residue with a moisture content of 70-85% with biomass additives at a dry basis mass ratio of 1:(0.8-1.2) for 30-60 minutes; (b) Place the mixture in a ventilation trough and turn it over at a frequency of ≥3 times / day and a depth of 50±5cm for the first 24 hours, while the bottom ventilation speed is 1.0-1.2m / s; (c) After 24 hours, continue to treat the material by turning it over ≥2 times / day and by ventilation speed of 0.5-0.8m / s. When the ambient humidity is ≤60%, treat for 2-4 days; when the ambient humidity is >60%, treat for 4-6 days, until the moisture content of the material is ≤15%. The biomass additive is selected from at least one of sawdust, rice husks, or straw fragments, wherein: the sawdust has a particle size of 0.5-3 mm and a moisture content of <12%; the rice husk has a crushed particle size of <5 mm; and the straw fragments have a crushed particle size of <8 mm. In steps (b) and (c), the turning and threshing operation is carried out by a trough-type turning and threshing machine (301). The blade of the turning and threshing machine has a wavy cutting edge, a cutting edge R angle of 0.5mm, and a blade installation tilt angle of 45°±10°. The blade is made of stainless steel with a hardness ≥HRC50. The drying system includes: (1) Mixing and stirring chamber (101), equipped with an online moisture content sensor; (2) Trench-type compost turner (301), with a span of 6-12m; (3) Ventilation unit, ventilation drying tank (201) includes a porous bottom plate with an opening ratio of 30±5% and an axial flow fan group; (4) The control unit, the control center (401), is configured as follows: When the moisture content sensor reading is >55%, increase the amount of biomass additive to a dry basis mass ratio of 1:1.2; When the moisture content sensor reading is <45%, reduce the amount of biomass additives to a dry basis mass ratio of 1:0.

8.

2. The drying system as described in claim 1, characterized in that, The pore size distribution of the porous base plate satisfies the following: 60±5% of the pores are 0.5-1mm in diameter; and 40±5% of the pores are 1-2mm in diameter.

3. The drying system as described in claim 1, characterized in that, The ventilation unit is connected to an ozone generator, and the ozone output concentration is controlled between 0.1 and 0.3 ppm.

4. A dried material prepared by the high-efficiency drying technology of mixing biomass waste with urban domestic sewage sludge as described in claim 1, characterized in that, Moisture content ≤15%; after being treated for 3 minutes by a vibrating screen with an amplitude of 1mm and a frequency of 50Hz, the sieve passing rate of a 3mm standard sieve is ≥95%.

5. A method for preparing biomass fuel, characterized in that... include: The dried material obtained by mixing biomass waste and urban domestic sewage sludge with the efficient drying technology described in claim 4 is granulated by ring die extrusion with a ring die compression ratio of 6:1-8:1 and a molding temperature of 80±5℃.

6. An application of a highly efficient drying system for mixing biomass waste and municipal sewage sludge as described in claim 1 in a municipal sewage sludge treatment plant, characterized in that: The length of a single treatment tank is ≥30m, the width matches the span of the turner, and the depth is 1.2-1.5m.

7. A biomass fuel pellet, prepared by the biomass fuel preparation method according to claim 5, characterized in that: Biomass fuel pellets have a diameter of Φ8-10mm; Bulk density ≥ 650 kg / m³ 3 .

Images