Practical methods for reducing raw material waste in ring die granulators

fertilizer granulator Sep 29, 2025

In fertilizer production, raw material waste in ring die granulators primarily stems from substandard pellets and die blockage. Targeted measures can increase raw material utilization by 5%-8%.

First, substandard pellets are recycled. After screening in the pelletizer, broken and large particles are collected and crushed to the required particle size (consistent with new raw material) using a dedicated fertilizer crusher. These particles are then mixed with new raw material at a ratio of 1:5 for re-pelletization. Care should be taken to control the moisture content during mixing. If the moisture content of the recycled material exceeds 18%, it should be air-dried to 14%-16% before mixing to prevent moisture absorption and impact on the overall pelletizing effect. Furthermore, the recycled material mix ratio should not exceed 20% to prevent it from affecting the strength of the new pellets.

Secondly, reduce ring die blockage losses. Before each shutdown, empty the pelletizing chamber of any remaining raw material. Then, introduce a small amount of talcum powder (5-8 kg per ton of raw material). Run the ring die granulator at no load for 5 minutes to allow the talcum powder to adhere to the inner wall of the ring die, forming a protective film to prevent residual raw material from solidifying and clogging. During daily production, check the ring die holes for blockage every four hours. If a small blockage is detected, clear it with a special needle (0.5 mm smaller in diameter than the die hole) to prevent further blockage and material waste.

In addition, polish the edges of the ring die holes every 100 hours to remove burrs and minimize material loss caused by material being stuck in the holes. A magnetic separator should be installed at the pelletizer feed inlet to remove metallic impurities from the raw material, preventing them from damaging the ring die and causing pelletizing problems, further reducing material waste.

Optimizing the linkage between the ring die granulator and front-end raw material processing

fertilizer granulator Sep 29, 2025

The granulation performance of a ring die granulator isn’t solely determined by the equipment itself. Linkage optimization with the front-end crushing, mixing, and conditioning processes can significantly improve production efficiency and pellet quality.
During the crushing process, the raw material particle size must be matched to the ring die aperture. For an 8mm ring die aperture, the raw material particle size should be controlled below 2mm, with a particle size deviation of no more than 0.5mm, to prevent large particles from clogging the die aperture. A grading screen can be installed at the pulverizer outlet, with the screen aperture set to 1/4 the ring die aperture, to ensure uniform particle size and reduce the frequency of granulator downtime for cleaning. If the raw material contains a high amount of coarse fiber (such as straw powder), the pulverizer should use a hammer-type mechanism to enhance crushing efficiency.

The mixing process must ensure uniformity among the raw materials, binders, and nutrients. Uneven mixing can result in insufficient nutrients or insufficient strength in some pellets. A typical requirement for uniformity is a coefficient of variation of ≤7%. This can be achieved by adjusting the mixer speed (30-40 rpm) and mixing time (5-8 minutes). Sampling points should be set up at the fertilizer mixer outlet for hourly testing.
During the conditioning process, the steam supply should be adjusted according to the production speed of the ring die granulator. For example, if the pelletizer processes 5 tons of raw materials per hour, the steam supply should be maintained at a stable 0.3-0.4 tons/hour, monitored in real time by a flow meter. If the pelletizer speed is increased to 6 tons/hour, the steam supply should be increased to 0.45-0.5 tons/hour to prevent the raw materials from being too dry or too wet.
By coordinating the speed and flow of the front-end and pelletizer, production efficiency can be increased by 10%-15%, reducing downtime caused by process disconnects.

How to adapt a BB fertilizer blender to different raw material characteristics?

fertilizer granulator Sep 29, 2025

BB fertilizer raw materials come in a variety of forms (granular, powdered, and fiber-containing). BB fertilizer blenders require targeted adjustments to accommodate these different raw material characteristics and avoid mixing problems.

For pure granular raw materials (such as urea and diammonium phosphate granules), which have relatively small density differences but are prone to rolling and stratification, the BB fertilizer blender should be equipped with guide plates within the mixer drum to guide the raw materials into upward and downward circulation and control the feed order. Adding the denser diammonium phosphate first, followed by the lighter urea, can reduce initial stratification. The speed can be appropriately reduced in the later stages of mixing to prevent excessive collisions between particles that could lead to breakage.

If the raw materials contain powdered ingredients (such as potassium chloride powder or trace element powder), a dustproof seal should be installed at the BB fertilizer blender feed port to prevent dust from escaping. Additionally, an atomizing humidifier (control the humidity to ≤15%) should be installed within the mixer drum. A small amount of humidification can enhance adhesion between the powdered raw materials and the granules, preventing dust from becoming suspended.

When the raw materials contain fiber organic fertilizer (such as fermented straw powder), it is necessary to use a paddle with a shearing function to prevent the fibers from entangled and clumping. At the same time, the fiber raw materials should be crushed to less than 3mm in advance to reduce mixing resistance. During the mixing process, the machine can be stopped and observed every 3 minutes. If fiber clumps are found, the paddle angle needs to be adjusted to enhance the shearing and dispersion effect to ensure that the fibers and granular fertilizer are fully integrated.

Different fertilizer types require special adaptation requirements for ring die granulators

fertilizer granulator Sep 29, 2025

In fertilizer production, ring die granulators must adjust core parameters based on the characteristics of different raw materials, such as organic fertilizer, compound fertilizer, and slow-release fertilizer, to ensure optimal granulation.

For organic fertilizers, whose raw materials often contain fiber components such as straw and fermented manure, ring die granulators require large-aperture ring dies (typically 8-12mm) and anti-entanglement rollers to prevent fiber entanglement and pelletizing stalls. Furthermore, the steam injection time should be appropriately extended during the conditioning stage to enhance the viscosity of the fiber raw material.

If producing bio-organic fertilizers containing live bacteria, a rapid cooling device should be added after granulation to reduce the pellet temperature to below 35°C to prevent high temperatures from killing the live bacteria.

Compound fertilizer raw materials are primarily nitrogen, phosphorus, and potassium powders, which are prone to moisture absorption and agglomeration. Therefore, granulators require ring dies made of wear-resistant materials (such as alloy steel) to minimize wear on the die holes, and the roller pressure must be precisely controlled. Excessive pressure can cause components like nitrate nitrogen in the raw materials to decompose and be lost due to the high extrusion temperature, while too little pressure can cause the granules to become loose.

Slow-release fertilizers, however, contain special ingredients like coating agents, so the ring die granulator requires a lower extrusion temperature (below 30°C). This is usually achieved by reducing the roller speed (from 30 rpm to 20 rpm) and adding a cooling device to prevent high temperatures from damaging the slow-release coating structure and ensure the fertilizer’s slow-release effect.

Double Roller Press Granulator: Revolutionizing Fertilizer Production

fertilizer granulator Sep 28, 2025

Exploring How Efficient Granulation Technology is Transforming Organic and NPK Fertilizer Production

The double roller press granulator represents a significant advancement in NPK fertilizer production technology, offering a dry granulation method that eliminates the need for drying processes. As a specialized NPK fertilizer granulator, this equipment operates through two synchronized rollers that apply extreme pressure to compact powdered materials into solid granules. In NPK fertilizer production line configurations, the double roller granulator excels at processing mineral-based blends with precise nutrient ratios, while the rotary drum granulator typically handles materials requiring liquid binders and thermal drying.

When comparing equipment applications, the double roller granulator in organic fertilizer production line settings is ideal for creating dense, slow-release organic-mineral composites, whereas rotary drum systems better suit pure organic materials needing spherical shaping. This technological differentiation allows production engineers to select the optimal granulation method based on material characteristics, with roller presses providing energy-efficient compaction for moisture-sensitive formulations and drum granulators offering versatility for diverse feedstock in both organic fertilizer production line and NPK fertilizer production line applications.

Introduction: The Granulation Technology Revolution

In the modern fertilizer production industry, the double roller press granulator is fundamentally transforming traditional granulation methods with its unique working principle and exceptional performance. This equipment utilizes two counter-rotating rollers to compress powdered raw materials into uniform granules under high pressure, significantly enhancing both production efficiency and fertilizer product quality.

The double roller press granulator has gained widespread popularity due to its adaptability to diverse production requirements—delivering outstanding granulation results in both NPK fertilizer production lines and organic fertilizer production lines.

Differences Between NPK Fertilizer Granulators and Organic Fertilizer Granulators

NPK Fertilizer Granulator

NPK fertilizer granulators are specifically designed for chemical fertilizers, typically processing dry mineral powders. Their granulation process requires precise control of chemical composition ratios to ensure uniform distribution of nitrogen, phosphorus, potassium, and other nutrients. In NPK production lines, the double roller press granulator efficiently handles high-hardness raw materials, producing strong, crush-resistant granular fertilizers.

Organic Fertilizer Granulator

Organic fertilizer granulators primarily process raw materials rich in organic matter, such as livestock manure and crop straw. These materials typically have high moisture content and significant fiber content, requiring special pretreatment. In organic fertilizer production lines, the double roller press granulator effectively processes these viscous materials by adjusting pressure and mold specifications, producing high-quality granular fertilizers suitable for organic agriculture.

Working Principle of the Double Roller Press Granulator

The core working principle of the double roller press granulator is based on “dry granulation” technology, which achieves granulation through pure physical pressure without adding liquid binders. The process can be divided into several key steps:

Raw materials are evenly fed between two counter-rotating rollers through a feeding system

The roller surfaces are engraved with specially shaped molds that compress the material into the molds under high pressure

The material undergoes plastic deformation under high pressure, creating powerful molecular bonds between particles

The formed granules are carried out as the rollers rotate, naturally separating as the final product

This process is not only energy-efficient and environmentally friendly (requiring no drying stage) but also produces granules with uniform chemical composition, regular shape, and high mechanical strength, facilitating storage, transportation, and application.

Application Advantages in Different Production Lines

In NPK production lines, the double roller press granulator enables precise control over granule density and strength, ensuring chemical fertilizers remain intact during long-distance transportation and mechanical spreading. Its enclosed design effectively reduces dust pollution and improves the working environment.

In organic fertilizer production lines, this equipment can process high-fiber, high-moisture organic raw materials, producing granular fertilizers that meet organic agriculture standards by adjusting process parameters. Its low-temperature granulation characteristic also helps preserve the activity of beneficial microorganisms in organic fertilizers.

Whether in NPK production lines or organic fertilizer production lines, the double roller press granulator demonstrates remarkable adaptability and efficiency, becoming an indispensable key equipment in modern fertilizer production.

Conclusion: Future Prospects

As global emphasis on sustainable agriculture and environmentally friendly production continues to grow, double roller press granulation technology will continue to evolve, providing the fertilizer industry with more efficient and eco-friendly solutions. Its unique advantages will ensure its increasingly important role in future NPK fertilizer production and organic fertilizer manufacturing.

The Magic Behind Disc Granulators: How Do They Work?

fertilizer granulator Sep 28, 2025

The disc granulator operates on a simple yet brilliant principle: a rotating inclined disc creates a cascading motion that forms perfect fertilizer spheres. Unlike the high-pressure fertilizer roller press machine which compacts materials through mechanical force, the disc granulator machine relies on centrifugal force and liquid binders for granulation. In NPK manufacturing process, this equipment plays a crucial role when combined with an NPK blending machine – first achieving homogeneous nutrient mixing, then transforming the blend into uniform granules through the disc’s tumbling action. This combination ensures the NPK fertilizer granulator machine produces consistent, dissolution-controlled pellets ideal for precise agricultural application.

Power Transmission: A Precision Mechanical Symphony

When the main motor activates, an exquisite mechanical ballet begins. The pulley and V-belt smoothly transfer power to the reducer, which through precise gear sets (perfect meshing of pinion and bull gear) ultimately delivers motion to the main shaft. This specially designed transmission system acts as the equipment’s “heart”, providing stable yet powerful support for the entire granulation process.

Granulation Stage: The Magic Show of Rotating Disc

The tilted disc mounted on adjustable supports serves as the central stage for granulation. As raw materials evenly enter from the feed inlet, they begin their magical transformation with the disc’s rotation. With precise moisture addition from spray nozzles, powder materials miraculously aggregate into uniformly-sized spherical granules.

Self-Cleaning: Intelligent Durability Assurance

The automatic cleaning device above the disc acts like a faithful butler, constantly removing residual materials. This innovative design not only ensures consistent granule quality but extends equipment lifespan by over 40%. When you see the machine maintaining like-new performance after months of continuous operation, you’ll appreciate this feature’s true value.

Continuous Production: An Industrial Efficiency Revolution

With the motor’s uninterrupted operation, materials undergo continuous feeding → granulation → automatic discharge in a perfect cycle. This continuous production method completely overcomes traditional batch processing limitations, tripling production efficiency compared to conventional equipment – perfectly meeting modern mass production demands.

Engineering Wisdom: Simplicity Behind Complexity

Behind the seemingly simple rotating disc lies multidisciplinary engineering wisdom encompassing transmission optimization, materials science, and fluid dynamics. It’s these invisible technical details that establish disc granulators’ irreplaceable position across fertilizer, feed, and numerous other industries.

Practical optimization directions for energy saving and consumption reduction in fertilizer coating machines

fertilizer granulator Sep 28, 2025

Currently, fertilizer companies are focusing on controlling production costs. Through proper optimization, coating machines can achieve energy savings and consumption reduction, helping companies lower operating costs.

First, energy saving in the heating system. Some coating machines utilize a waste heat recovery design. A heat exchanger is installed at the heat sealing channel outlet to collect the exhaust hot air and preheat the incoming cold air, reducing heat consumption in the heating tubes. This design reduces heating energy consumption and is particularly suitable for companies with continuous production, with significant energy savings over the long term. Furthermore, variable frequency heating tubes are used, which automatically adjust power based on particle flow rate. For example, when production capacity drops to 50%, heating power is also reduced, avoiding high-temperature operation and wasting energy during idle periods.

Second, motor frequency conversion modification. The equipment’s conveyor belts, film reels, and other motors utilize variable frequency control. During production, the PLC system is linked to a particle flow sensor to automatically adjust motor speed based on particle flow rate. Compared to traditional fixed-speed motors, variable-frequency motors can save 10%-12% of electricity, operate more smoothly, and reduce noise by 5-10 decibels, improving the workshop working environment.

Third, film utilization is improved. Some coating machines support adaptive film width adjustment. When changing films of different widths, manual adjustment of the film guide mechanism is eliminated, and the optimal wrapping width is automatically matched. This reduces material loss during the commissioning process. Long-term use can significantly reduce raw material procurement costs, supporting enterprises in reducing costs and increasing efficiency.

How do fertilizer coating machines solve the problem of pellet clumping?

fertilizer granulator Sep 28, 2025

Fertilizer pellets are prone to clumping during storage and transportation. Through scientific design, coating machines address this issue at its root, focusing on the following key aspects.
First, uniform film coating and protection. The coating machine uses vibrating feeders, combined with guide plates, to evenly distribute pellets. Even pellets of varying sizes are diverted by the guide plates, ensuring that every pellet contacts the film. The symmetrical film guide mechanism wraps the pellets from all sides, creating a complete seal that blocks moisture from reaching the pellets and prevents moisture absorption and clumping. Furthermore, the film tension is precisely controlled, with an error within ±2N. This prevents over-tightening of the pellets, keeping them loose and facilitating even spreading during subsequent fertilization.

Second, precise temperature control is crucial. During the heat-sealing stage, the coating machine uses an intelligent thermostat to maintain a stable temperature of 100-150°C and monitors temperature fluctuations in real time, with fluctuations within ±5°C. This ensures that the film adheres tightly to the pellets, forming a strong protective layer. It also prevents high temperatures from damaging anti-caking components in the fertilizer (such as the coating agents in some slow-release fertilizers), preserving the pellets’ inherent anti-caking properties. The hot air circulation design also ensures a uniform temperature throughout the packaging, preventing uneven shrinkage of the film and damaging the protective layer. Even the slightest movement of the pellets within the package prevents the film from rupturing.

Controlling pellet strength in ring die granulators: Key to fertilizer transportation and storage

fertilizer granulator Sep 28, 2025

Pellet strength is a core performance indicator for fertilizer products. Ring die granulators require multi-step control to ensure pellets can withstand the pressure of transportation and stacking, minimizing breakage and loss.

First, consider the raw material ratio. If the organic matter content in production is too high (over 60%), binders such as clay and bentonite should be added (control the amount to 3%-5%) to increase the viscosity of the raw materials and lay the foundation for pellet strength.

If the proportion of inorganic fertilizer is high, the moisture content of the raw materials should be controlled between 14% and 16% to avoid pellet brittleness caused by too low a moisture content and easy sticking to the ring die granulator due to too high a moisture content.

Selecting the ring die granulator compression ratio is also crucial. The compression ratio (the ratio of the ring die aperture to the effective thickness) should be adjusted according to the fertilizer type. For organic fertilizers with high fiber content, a low compression ratio of 1:8-1:10 is recommended to prevent pellets from being too hard and easily broken. For compound fertilizers, a high compression ratio of 1:12-1:15 is recommended to enhance pellet density. During production, regular spot checks can be performed using a pellet strength tester. If the strength is insufficient, the steam supply to the conditioner can be temporarily increased (by 10%-15%).

In addition, the gap between the roller and the ring die should be controlled within a range of 0.1-0.3mm. A gap too large will cause the raw material to slip, resulting in insufficient pellet density; a gap too small will increase wear and affect pellet consistency. By synergistically controlling these three factors, the compressive strength of fertilizer pellets can be stabilized at above 20N, meeting transportation and storage requirements.

Working principle of the fertilizer granule coating machine: Core design adapted to fertilizer characteristics

fertilizer granulator Sep 28, 2025

In fertilizer production, the core function of the coating machine is to address the issues of loose granules and their tendency to absorb moisture and agglomerate. Its workflow is precisely designed based on fertilizer characteristics.

First, during the granule conveying process, the coating machine utilizes an “anti-scattering conveyor belt + vibrating discharge mechanism” to prevent granule accumulation. A flow sensor controls the conveying rate, ensuring that each batch of granules enters the coating area evenly. Even with materials with complex ingredients and uneven particle sizes, such as compound fertilizers, this ensures a uniform distribution of granules of varying sizes, paving the way for subsequent coating.

Next, the film wrapping process occurs. To prevent fertilizers from absorbing moisture, PE or PP film is often used. A film guide mechanism, combined with a particle deflector, tightly wraps the granules from all sides. An adaptive tension system adjusts the film tension based on granule flow to prevent leakage or agglomeration. The heat-sealing and shaping process is particularly critical. The coating machine utilizes hot air circulation to achieve film shrinkage while preventing the loss of fertilizer components due to high temperatures. For example, urea fertilizers are prone to decomposition above 160°C, and precise temperature control maximizes nutrient retention. Zoned temperature control also prevents localized overheating that can lead to pellet clumping, ensuring that pellets remain loose after coating.

Finally, the packaging is cut to pre-set specifications and the bag opening is simultaneously compacted to ensure packaging integrity. This process addresses both fertilizer storage and transportation requirements, ensuring that the packaging is protected from damage and leakage, even during bumpy long-distance transport.