Flat die granulator: Solving the problem of fiber entanglement in organic fertilizer

Fiber raw materials such as straw, mushroom residue, and rice husks are common components in organic fertilizer production. However, these materials are prone to fiber entanglement with the rollers during pelletizing, leading to equipment stalls and a sharp drop in pelletizing efficiency. The flat die granulator, with its targeted structural design, is an ideal solution for this problem.

The core cause of fiber entanglement is insufficient cleavage of long fibers in the raw material, or a smooth roller surface that causes fibers to entangle as the rollers rotate. The flat die granulator’s design addresses this problem by focusing on two key points: First, the flat die holes feature a “deep straight hole” layout (15-20mm depth). This shortens the vertical force path when the fiber raw material is squeezed into the hole, reducing the fiber’s residence time between the rollers and the flat die.

Second, a pre-crushing pretreatment is recommended, with the fiber raw material pulverized to 0.5-1mm to ensure that long fibers are cut, thus reducing the likelihood of entanglement at the source.

In actual production, if slight entanglement still occurs, the gap between the roller and the flat die can be adjusted to maintain 0.2-0.3mm, or 1%-2% bentonite can be added to the raw materials for further optimization. This solution can increase the smoothness of granulation of fiber raw materials to over 90%, avoiding frequent downtime for cleaning and ensuring stable operation of the organic fertilizer production line.

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.

Double screws compost turning machine: The “Core of Efficient Turning” for organic fertilizer fermentation

In organic fertilizer production, the quality of compost turning during the fermentation process directly determines fertilizer maturity and nutrient retention. The double screws compost turning machine, with its unique structural design, is a key device for addressing uneven compost turning and slow fermentation. Its dual helical operation ensures sufficient oxygen and uniform heat dissipation within the fermentation tank, significantly improving fermentation efficiency.

The core working components of the double screws compost turning machine are two sets of parallel spiral blades. As the device moves along the fermentation tank track, the blades rotate clockwise, tossing the bottom material upward while simultaneously dispersing it to the sides. This turning method creates a “rolling up and down, mixing left and right” motion pattern for the material.

During the fermentation process, turning the compost not only provides sufficient oxygen for microorganisms but also quickly dissipates heat generated by the fermentation process, preventing nutrient loss due to localized high temperatures. For different raw materials such as livestock and poultry manure, straw, etc., the spiral speed and double screws compost turning machine movement speed can be adjusted to control the turning depth (up to 1.5-3m) and frequency, ensuring that the materials are fully composted within 7-15 days. Compared with manual turning, the efficiency is increased by more than 10 times.

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.

Key considerations for drum fertilizer dryer selection

For fertilizer companies, choosing the right drum fertilizer dryer not only ensures effective drying but also reduces subsequent energy consumption and maintenance costs.

1. Suitable Heating Method for Fertilizer Type

For organic fertilizer production (including fiber-based fermented materials), the preferred option is “hot air heating.” Direct contact between the hot air and the material results in faster drying and prevents fiber sticking to the wall. For compound fertilizer production (wet granules after granulation), the “steam heating” option offers a milder temperature and reduces granule breakage. For low-temperature drying of biofertilizers (to prevent inactivation of microbial inoculants), the “low-temperature hot air” option is recommended to preserve microbial activity.

2. Matching Drum Specifications to Production Capacity

The drum diameter and length directly determine the processing capacity. When selecting a drum fertilizer dryer, calculate the hourly processing capacity based on the daily production capacity, allowing for a 10%-15% margin to ensure sufficient material residence time.

3. Targeted Selection of Anti-Stick Designs

High-humidity organic fertilizers tend to stick to the inner wall of the drying drum. When selecting a drum fertilizer dryer, confirm whether it features an anti-sticking skimmer or polished inner wall treatment to reduce material residue and avoid frequent downtime for cleaning. When processing highly sticky wet compound fertilizer pellets, a combination of a guide plate and skimmer can be used to guide material flow smoothly.

4. Energy Consumption and Environmental Parameters

Prioritize equipment with high thermal efficiency to reduce fuel waste. Also, consider the suitability of exhaust gas treatment. The hot and humid exhaust gas generated during the drying process requires dust removal and desulfurization equipment to ensure compliance with environmental emission standards in the fertilizer industry.

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 granulator: Understanding the “Simple and Efficient” logic of granulation

In fertilizer granulation production, flat die granulators are the preferred equipment for small and medium-sized enterprises due to their simple structure and easy operation. They are particularly suitable for fertilizers with complex raw material characteristics, such as organic fertilizers and biofertilizers. The core of their granulation principle lies in the vertical extrusion design of a “flat die + roller” system, which ensures effective granulation while reducing operational complexity.

The core components of a flat die granulator are a horizontally positioned circular die (flat die) and one or two rollers above it. Cylindrical holes are evenly distributed across the die surface. Raw material falls from the feed inlet between the die and rollers. A motor drives the rollers to rotate, and friction forces the rollers continuously press the raw material against the die surface, forcing it into the holes.

In the die holes, the raw material undergoes a process of “extrusion shaping → solidification forming.” A scraper below the die cuts the cylindrical material that emerges from the holes, forming pellets of uniform length.

Compared to other granulation equipment, the flat die granulator’s advantage lies in its adaptability to fibrous raw materials (such as fermented straw). The vertical compression of the rollers prevents fiber entanglement and facilitates die hole cleaning, making it suitable for the production of small and medium-sized batches of a wide variety of fertilizers.

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 granulator: What is the core mechanism of pellet formation?

In fertilizer granulation production, the ring die granulator is a key piece of equipment for achieving “powdered raw materials → uniform granules.” It is particularly suitable for a variety of fertilizer types, including organic fertilizers, compound fertilizers, and biofertilizers. The key to its granule formation lies in the synergistic effect of the “ring die + press roller” system, as well as precise adaptation to the raw material characteristics.

The core working components of the ring die granulator are a ring die with densely packed holes (ring die) and two to three press rollers within it. When the machine is started, pre-treated (mixed and conditioned) fertilizer raw materials (usually with a moisture content of 15%-25%) are fed into the extrusion chamber between the ring die and the press rollers. The motor drives the ring die at high speed, while the press rollers follow in the opposite direction. Friction forces press the raw materials tightly against the inner wall of the ring die.

As the ring die continues to rotate, the raw materials are forcibly squeezed into the small holes of the ring die, where they undergo a process of “extrusion → shaping → solidification.” The shape of the small holes (circular, cylindrical, or oblate) determines the appearance of the pellets, while the length-to-diameter ratio of the holes (also known as the “compression ratio”) influences pellet hardness.

Finally, the formed pellets are cut by a scraper on the outside of the ring die, forming uniform fertilizer granules. The entire process achieves “continuous feeding and continuous granulation,” adapting to the mass production needs of organic fertilizer production lines.

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.