The journey from organic waste to high-efficiency fertilizer

The bio-organic fertilizer production line utilizes organic waste such as livestock and poultry manure, straw, and mushroom residue as raw materials. Through microbial fermentation technology, it recycles resources and produces fertilizer rich in active bacteria and organic matter. Bio-organic fertilizer production lines serve as a vital link between the livestock and poultry industry, the agricultural industry, and the environmental protection industry.

Raw material pretreatment is a fundamental step. It requires crushing and screening the organic waste to remove impurities and ensure a uniform particle size (approximately 80 mesh). Auxiliary materials are then added to adjust the carbon-nitrogen ratio (25-30:1) and humidity (55%-65%) to create a suitable environment for microbial growth. This phase then enters the inoculation and fermentation stage, where specialized microbial agents are added to the mixture. A compost turning machine regularly turns the compost to provide oxygen, maintaining a temperature of 55-65°C. Composting continues for 20-30 days, effectively killing pathogens and insect eggs and breaking down large organic molecules.

The fermented material undergoes post-processing to optimize quality. First, it undergoes low-temperature drying to reduce moisture to below 12% to prevent mold and mildew during storage. It then undergoes crushing, screening, and grading, with unqualified particles returned to the pre-processing stage for recycling. Finally, functional microbial agents can be optionally added to the mix to enhance the bioactivity of the fertilizer, depending on crop needs. The resulting pellets are uniform and rich in humic acid, amino acids, and a variety of beneficial bacteria, providing nutrients for crops while also improving the soil microbial ecosystem.

Windrow compost turning machine: Efficient equipment for converting livestock manure into organic fertilizer

In the resource utilization of livestock and poultry waste, windrow compost turning machines, with their flexible and efficient operation, have become a core piece of equipment for converting livestock manure into organic fertilizer. Through mechanized turning and plowing, they accelerate manure composting and fermentation, transforming livestock pollutants into high-quality organic fertilizer, addressing environmental challenges while also promoting resource recycling.

The core advantage of windrow compost turning machines lies in their adaptability. Their crawler-type design allows for free movement in muddy composting areas. The large ground contact area and low pressure prevent them from sinking into the manure pile, making them suitable for various sizes of fermentation workshops or open-air sites. Equipped with a hydraulically driven turning gear shaft, the equipment can reach a turning depth of 0.8-1.5 meters, thoroughly mixing the bottom layer of manure with the surface material, breaking up compacted materials and ensuring uniform fermentation.

In the livestock manure processing process, windrow compost turners play a key role in promoting fermentation. First, livestock manure is mixed with supplementary materials such as straw and sawdust in appropriate proportions, adjusting the carbon-nitrogen ratio to 25-30:1 and the humidity to 55%-65% to create optimal conditions for microbial fermentation.

Subsequently, a compost turning machine regularly turns the pile, introducing sufficient oxygen to support aerobic microbial activity and rapidly dissipating the heat generated by fermentation, keeping the pile temperature between 55-65°C. This temperature range effectively kills pathogens, insect eggs, and weed seeds in the manure, preparing the compost for subsequent operation in the fertilizer granulator.

This equipment boasts high efficiency and a high degree of automation. By setting the turning frequency and path, continuous operation is achieved, reducing labor input.

Small pellets, big impact: The evolution of organic fertilizer through granulation

In organic fertilizer production, granulation is more than just a cosmetic enhancement. Its primary purpose lies in practicality. Powdered organic fertilizers have a low density and are bulky, taking up a lot of space during storage and transportation. They are also prone to generating dust, leading to nutrient loss and environmental pollution. Granulation compacts the material, significantly reducing its volume, making long-distance transportation and economical storage possible.

More importantly, granulation profoundly impacts the ease and efficiency of fertilization. Uniform granules facilitate mechanized spreading, adapting to the operational needs of modern large-scale farms. Furthermore, their compact structure regulates the release rate of nutrients into the soil, preventing rapid decomposition and providing a more stable and long-lasting nutritional supply for crops.

So, how are various agricultural and forestry wastes transformed into uniform granules? Currently, mainstream granulation processes, such as disc granulators and double roller press granulators, each have their own advantages.

The advancement of granulation technology, from dusty powder fertilizer to uniform, uniform granules, is a significant step toward the modernization and standardization of traditional organic fertilizers. It has transformed organic fertilizer from a traditional “homegrown” method into a standardized commodity that can be integrated into modern agricultural production systems. These tiny granules embody the industry’s unwavering pursuit of efficiency, environmental protection, and practicality.

Rotary drum granulator: The core “Shaping” equipment in fertilizer production

In fertilizer processing, the rotary drum granulator is a key piece of equipment for converting powder into granules. Its stable performance makes it a common choice for most fertilizer production scenarios.

Structurally, the core of a rotary drum granulator consists of an inclined drum, a drive system, a spray device, and a heating and insulation layer. The drum’s tilt angle can be adjusted based on the characteristics of the raw material, typically controlled at 3°-5°. This ensures adequate tumbling of the raw material while preventing the granules from clumping due to prolonged dwell time. The drive system drives the drum at a constant speed of 10-20 rpm via gears or belts, ensuring a stable and controllable granulation process.

During operation, mixed fertilizer raw materials enter the drum through the feed inlet. As the drum rotates, the raw materials continuously tumble and collide within the drum. Simultaneously, a spray device applies an appropriate amount of binder to the raw materials, gradually agglomerating them into small granules. The heating and insulation layer maintains the temperature inside the drum within an optimal range, helping the granules quickly solidify and form. Finally, the formed fertilizer granules are discharged from the discharge port and enter the subsequent screening and cooling stages.

This rotary drum granulator’s advantage lies in its wide adaptability. Whether it’s nitrogen-phosphorus-potassium compound fertilizer, organic fertilizer, or biological fertilizer, efficient granulation can be achieved by adjusting parameters. The highly uniform granulation and moderate granule strength facilitate subsequent storage and transportation, providing equipment support for the large-scale advancement of fertilizer production.

How does a disc granulator create round, uniform fertilizer granules?

The roundness and uniformity of fertilizer granules directly impact the ease of application (spreading uniformity) and product competitiveness. Disc granulators, with their unique “rolling forming” principle, are key equipment for producing high-quality granules. The key lies in precisely controlling parameters to achieve the ideal shaping process within the disc.

Disc granulators do not rely on extrusion to form granules, but instead continuously roll the raw materials within a rotating disc. Initially small granules continuously absorb surrounding powder, gradually growing larger like a “snowball.” During this process, the granules rub against each other, naturally forming a rounded appearance. These granules are particularly suitable for products with high requirements for granule shape, such as organic fertilizers and biological fertilizers.

Pellet quality is determined by several parameters. The first is the disc’s inclination angle. A small angle prolongs the material’s residence time within the disc, resulting in larger particles. A large angle causes the particles to overflow quickly, resulting in smaller particles. The second is the disc’s rotational speed. Low speeds are suitable for low-viscosity raw materials, preventing powder splashing; high speeds are suitable for sticky raw materials like organic fertilizer, enhancing the rolling adsorption effect. The third is the feed rate. Maintaining a uniform feed rate prevents excessive feed from causing particle accumulation and deformation, while insufficient feed leads to uneven particle size.

Furthermore, for fertilizers such as biofertilizers that require the preservation of bacterial inoculants, disc granulators eliminate the need for high-temperature extrusion. The forming process temperature is kept below 40°C, ensuring the survival of the inoculant. The resulting rounded particles are easy to package and transport, ensuring both functionality and commercial appeal.

Common troubleshooting and solutions for double screws compost turning machines

Double screws compost turning machines operate frequently in organic fertilizer fermentation workshops. Improper operation or untimely maintenance can easily lead to problems such as uneven turning, insufficient power, and equipment jamming, impacting fermentation progress.

1. Dead corners remain after turning, and some areas remain uncomposted

The main cause is excessive clearance between the spiral blades and the sidewalls of the fermentation tank (over 10 cm), or the double screws compost turning machine is moving too fast, preventing material from being turned over the edges. To address this, adjust the position of the spiral blades to reduce the clearance to within 5 cm. Also, reduce the double screws compost turning machine’s speed to ensure that every area is thoroughly turned.

2. Motor overload and tripping, insufficient power

This is often caused by excessive moisture content (over 70%) in the raw materials, resulting in increased friction on the spiral blades due to high viscosity, or by large impurities in the raw materials that may be blocking the blades. To address this, adjust the moisture content of the raw materials to 60%-65% before clearing impurities from the fermentation tank. If the compost tank is frequently overloaded, check the tightness of the motor belt and tighten or replace it.

3. Rapid wear of spiral blades, reducing turning capacity

This is primarily due to the presence of hard impurities (such as sand and gravel) in the raw materials, or the blade material not being suitable for wear resistance. To address this, install a screen to filter out hard particles before the raw materials arrive. Regularly inspect the blades for wear. If the blade thickness has decreased by 1/3 or cracks appear, replace them promptly.

Drum fertilizer dryer: The logic of “Efficient Dehydration” for high-moisture fertilizers

In fertilizer production, high-moisture raw materials (such as fermented organic fertilizers and wet materials after compound fertilizer granulation) are prone to caking and mold if not dried promptly, affecting product quality and storage life. Drum fertilizer dryers, with their “continuous drying + uniform heating” characteristics, have become a core dehydration equipment in the fertilizer industry. Their operating principle is precisely adapted to the characteristics of fertilizer raw materials.

The core structure of a drum fertilizer dryer is an inclined rotating drum equipped with a heating system and a discharge device. During operation, high-moisture fertilizer (30%-50% moisture content) enters the drum through the high-end feed port. The motor drives the drum to slowly rotate, continuously turning the material and moving it forward. Simultaneously, the high-temperature hot air generated by the heating system fully contacts the material, rapidly removing moisture from the material through a dual heat transfer process of “convection and conduction.”

To prevent fertilizer clumping, a lifting plate is often installed inside the drum. This plate continuously lifts and drops the material, increasing the heating surface and ensuring uniform drying of each portion. The drum’s tilt angle is adjustable to control the material’s residence time within the drum, thereby precisely controlling the moisture content after drying. The entire process is continuous and stable, suitable for the mass production needs of organic fertilizer production lines. The dried material is loose and free of lumps, eliminating the need for secondary crushing.

Flat die granulators: Why are they suitable for small and medium-sized organic fertilizer companies?

Small and medium-sized organic fertilizer companies are characterized by moderate production capacity, diverse raw materials, and large batch sizes. The design features of the flat die granulator perfectly meet these needs, making it a cost-effective choice for these companies.

1. Low Equipment Investment Cost

The flat die granulator has a relatively simple structure and does not require a complex transmission system. The purchase cost of a single unit is only 60%-70% of that of similar granulator equipment with similar production capacity. Furthermore, installation does not require a complex foundation, saving small and medium-sized companies from the high initial investment.

2. Flexible Raw Material Adaptability

Small and medium-sized organic fertilizer companies often purchase local raw materials, which can have large fluctuations in moisture and fiber content. The flat die granulator’s wide adaptability allows it to handle high-fiber straw materials, and the vertical compression of the rollers prevents tangling. For fermented materials with slightly higher moisture content, the flat die surface is easy to clean and prevents sticking.

3. Convenient Production Changeover

Small and medium-sized companies often produce a variety of products in small batches, requiring frequent adjustments to pellet size. It only takes 1-2 people to replace the flat die of the flat die granulator, and it can be completed within 30 minutes. In addition, the cost of flat dies with different apertures is low. The company can reserve multiple sets of flat dies and quickly switch product specifications to meet the needs of different customer orders.

Ring die granulators: Why can they adapt to the different needs of organic and compound fertilizers?

In the fertilizer industry, the physical properties of organic fertilizers (mostly made from fermented manure and straw) and compound fertilizers (mostly made from phosphate rock, potassium chloride, and urea) differ significantly. Organic fertilizers are fibrous, highly moist, and prone to sticking together, while compound fertilizers are hard, fiberless, and require high-hardness molding. Ring die granulators, through their “adjustable structure + material adaptability,” can meet the granulation needs of both fertilizer types.

For organic fertilizer granulation, ring die granulators offer two key design advantages: First, they utilize a “low compression ratio” ring die (3:1-5:1) to avoid excessive compression that damages the organic matter and bacterial inoculant activity in the raw material, while ensuring that the granules do not break apart. Second, they feature an “anti-sticking die conditioning system” that precisely controls the amount of water added and a small amount of binder (such as starch residue) to reduce material sticking to the die, thereby improving molding efficiency and discharge speed.

For compound fertilizer granulation, the ring die granulator focuses on “wear resistance and high extrusion capacity”: the ring die is made of wear-resistant alloy material, which can withstand the high-frequency friction of mineral raw materials and has a service life three times longer than that of ordinary materials; the pressure roller is hardened to enhance the extrusion force, and is equipped with a “high compression ratio ring die” (6:1-8:1) to ensure that the hardness of the compound fertilizer particles meets the standard.

Why do fertilizer crushers require special adaptations for bio-fertilizer production?

The core difference between bio-fertilizer production and conventional organic fertilizer and compound fertilizer production lies in the need to preserve the activity of the inoculant. Furthermore, the raw materials often consist of specialized materials such as fungus residue, traditional Chinese medicine residue, and fermented straw. This places special demands on grinding equipment: low temperature, pollution prevention, and precise particle size. Through targeted modifications, fertilizer crushers have become the ideal choice for bio-fertilizer production.

1. Low-temperature crushing preserves inoculant activity

The functional bacteria in bio-fertilizer (such as Bacillus subtilis and phosphate-solubilizing bacteria) are not tolerant to high temperatures. Excessive frictional heat (above 45℃) generated during the grinding process can inactivate the bacteria. High-quality fertilizer crushers optimize the impeller speed (to avoid excessive friction) and some are equipped with a “water-cooling jacket” to circulate cold water to remove heat from the chamber walls, maximizing inoculant activity.

2. Anti-residue design prevents cross-contamination

Bio-fertilizer production often requires switching between different inoculant formulations. If residual material from previous batches remains in the equipment, bacterial strains can mix. The fertilizer crusher‘s “fully open cleaning structure” solves this problem. The grinding chamber door can be fully opened, and the smooth, corner-free interior allows for quick cleaning without disassembling core components, reducing the risk of cross-contamination.

3. Precise Particle Size for Microbial Agent Mixing

Bio-fertilizer production requires uniform particle size (typically 1-3mm) after grinding. Uneven particle size results in incomplete mixing of the microbial agent and raw material, impacting fertilizer efficiency. The horizontal crusher can precisely control particle size deviation within ±0.5mm, providing a high-quality raw material foundation for subsequent microbial agent inoculation and mixing.