Author: organic fertilizer production line

In the core process of NPK compound fertilizer production, the choice of granulation technology directly determines product quality, production costs, and market competitiveness. As a key decision point in the production process, drum granulation and twin-roll extrusion granulation represent two different technical routes, each suitable for different production scenarios. This article will systematically analyze the core characteristics and applicable boundaries of these two technologies based on industry practical experience, providing enterprises with clear technical logic and decision-making basis for selection.

I. Drum Granulation: A Mature Solution for Large-Scale Production

Drum granulation technology, with its stability, reliability, high capacity flexibility, and wide product applicability, has become the mainstream choice for large-scale compound fertilizer production enterprises.

Technical Advantages:

High Capacity and High Pelletizing Rate: Capacity range covers 1-20 tons/hour, with a pelletizing rate of over 90%, making it particularly suitable for large-scale continuous production.

Strong Raw Material Adaptability: Compatible with various basic raw materials such as urea, ammonium sulfate, diammonium phosphate (DAP), and potassium chloride, allowing for flexible formula adjustments.

Excellent Product Quality: High granule roundness and strength (typically ≥15N), not easily pulverized, suitable for long-term storage and long-distance transportation.

High Process Maturity: A complete supporting drying, cooling, and screening process system ensures good production stability.

Typical Application Scenarios: Suitable for large-scale production enterprises primarily producing general-purpose NPK compound fertilizers and pursuing economies of scale. For example, a Southeast Asian customer adopted Huaqiang Heavy Industry’s 20-ton/hour drum granulation production line, and through optimized automatic rubber liner cleaning technology, reduced equipment maintenance downtime and increased annual production capacity by 40%.

II. Twin-Roll Extrusion Granulation: An Innovative Path to Energy Saving and Customization

Twin-roll extrusion granulation technology, with “room temperature molding” as its core feature, breaks through the energy consumption bottleneck of traditional processes, providing a new technological option for small and medium-sized enterprises and specialty fertilizer production.

Technical Advantages:

Significant Energy Saving Effect: No drying stage required; overall energy consumption is reduced by approximately 40% compared to drum granulation, resulting in significant operating cost advantages.

Simple raw material processing: It has relaxed requirements on raw material particle size; coarse materials can be directly granulated without fine crushing, reducing investment in pretreatment equipment and energy consumption.

Suitable for heat-sensitive materials: Its room-temperature molding characteristics make it particularly suitable for adding trace elements (boron, zinc, iron, etc.) and certain easily decomposable organic components.

Flexible production organization: Suitable for flexible production of multiple varieties and small batches, with convenient product changeover.

Typical application scenarios: Particularly suitable for small and medium-sized enterprises in areas with high electricity costs, primarily producing specialty fertilizers/formulated fertilizers. For example, after adopting a 5-ton/hour double-roller extrusion production line, an Algerian customer not only met the local demand for specialty fertilizers but also controlled the raw material loss rate to below 3%, achieving a dual improvement in economic benefits and resource efficiency.

III. Selection Decision Matrix: Technology Matching Based on Corporate Strategy

When selecting granulation technology for an NPK compound fertilizer production line, enterprises should conduct a comprehensive evaluation based on the following four dimensions: If the product is positioned as a standardized product such as general-purpose NPK compound fertilizer, and the goal is large-scale continuous production (capacity typically higher than 5t/h), with raw materials mainly consisting of conventional inorganic materials requiring drying treatment, and higher energy consumption acceptable to achieve economies of scale, then roller granulation technology is more suitable. If the enterprise focuses on producing customized special-purpose or formula fertilizers containing trace elements, with capacity requirements of small to medium scale, multiple batches (1-10t/h), raw materials containing heat-sensitive components or uneven particle size, and is sensitive to electricity costs and prioritizes initial investment control, then double-roller extrusion granulation technology has advantages in system simplicity and energy saving, but roller wear needs to be closely monitored during operation.

IV. Technology Integration and Customized Solutions

It is worth noting that the two technologies are not entirely contradictory. Leading equipment suppliers such as Huaqiang Heavy Industry are able to provide hybrid process solutions or modular designs based on specific customer needs. For example, companies that produce both general-purpose fertilizers and develop specialty fertilizers can design a “dual-line parallel” or “flexible switching” production layout to maximize equipment utilization.

Granulation Technology in NPK Manufacturing

This analysis of drum versus roller press granulation highlights the critical technology choice within the broader npk fertilizer manufacturing process. Regardless of the chosen method, the process begins with precise formulation, typically using a npk blending machine or a fertilizer mixer machine to create a homogeneous powder blend. The core of the npk fertilizer production line is the npk granulation machine. The specific npk granulation machine technology selected—whether a rotary drum (wet) or a roller press (dry)—fundamentally defines the energy profile and product characteristics of the entire npk manufacturing process.

The entire suite of npk fertilizer granulator machine equipment, including the chosen npk fertilizer granulator, dryers, and coolers, must be configured to support the selected technology. For operations focused on physical blending rather than chemical granulation, a npk bulk blending machine may be the primary equipment. This underscores that npk fertilizer production technology is not a single path but a spectrum, where the selection of granulation equipment is the pivotal decision that aligns the production system with strategic business goals of scale, product type, and operational cost.

Therefore, investing in a deep understanding of these granulation technologies and their corresponding equipment requirements is essential for designing an efficient, competitive, and profitable NPK fertilizer production facility.

Conclusion: From Technology Selection to Value Creation The choice of granulation technology is essentially a technological interpretation of a company’s development strategy. For companies producing general-purpose fertilizers on a large scale, drum granulation remains a proven and reliable choice; while for companies focusing on niche markets and pursuing differentiated competition, twin-roller extrusion granulation offers a more cost-effective and flexible innovation path. It is recommended that companies, before making decisions, not only conduct techno-economic analysis but also consider their own resource endowment, market positioning, and development vision to choose a technology route that can truly support long-term competitiveness. Deep cooperation with equipment suppliers with rich project experience and conducting pilot-scale verification will be an important guarantee for reducing investment risk and ensuring the successful implementation of technology.

In the production of organic fertilizers, bio-fertilizers, and organic-inorganic compound fertilizers, granulation is a crucial process that gives the product its commercial form, improves application convenience, and enhances market value. Among numerous granulation equipment, the disc granulator, with its classic structure, intuitive operation, reliable operation, and outstanding cost-effectiveness, has always occupied a core position in small and medium-sized fertilizer production lines. Huaqiang Heavy Industry, combining years of technological research and development with project practice, provides an in-depth analysis of the application advantages, precise operation points, and systematic capacity optimization strategies of the disc granulator.

Core Advantages: Why Choose a Disc Granulator?

The advantages of the disc granulator stem from its ingenious working principle: well-mixed powdered materials are continuously fed into an inclined rotating disc, where, under the combined action of gravity, centrifugal force, and friction between materials, they continuously roll, agglomerate, and grow, ultimately forming uniform granules.

High pelletizing rate and excellent granule quality: Under mature process control, the pelletizing rate can typically be consistently maintained above 80%. The produced granules have good roundness, smooth surface, and excellent product appearance.

Easy to operate and maintain: The equipment structure is relatively simple, the operating principle is intuitive, and the technical requirements for operators are moderate. There are few daily maintenance points, and maintenance costs are significantly lower than some more complex models.

Highly adaptable and flexible: Particularly suitable for small-to-medium batch, multi-variety production, with convenient product formula switching. Good compatibility with organic materials, microbial agents, trace elements, and other additives.

Excellent cost-effectiveness: Under the same capacity requirements, its equipment purchase cost and subsequent energy consumption are usually more economical, making it an ideal choice for startups and cooperatives.

Precise Operation: Mastering Three Core Parameters While the disc granulator is “easy to use,” mastering its “effective use” hinges on the precise and coordinated control of three key process parameters: disc inclination angle, rotation speed, and raw material moisture content.

Disc Inclination Angle (typically 35°-55°): The inclination angle directly affects the residence time and rolling trajectory of the material within the disc. If the tilt angle is too large, the particles will roll off before they have grown sufficiently, resulting in a smaller particle size; if the tilt angle is too small, the particles will remain in the disk for too long, potentially causing overgrowth or even clumping. Fine-tuning is necessary based on material characteristics and the target particle size.

Disc rotation speed (typically 20-40 r/min): The rotation speed determines the magnitude of the centrifugal force on the material. Too high a speed will cause the material to be thrown towards the edge of the disk, resulting in insufficient rolling, irregular particles, and excessive powder; too low a speed will result in insufficient material lifting height, inadequate rolling, slow pelleting, and a wide particle size distribution.

Raw material moisture content (typically 25%-45%): Moisture acts as a “binder” for pelleting. Too low a moisture content will make it difficult for particles to form, resulting in more powder; too high a moisture content will cause the material to easily clump together, forming large pellets or causing a paste-like substance in the disk. Moisture content needs to be adjusted in conjunction with the amount of binder (such as bentonite or lignin sulfonate).

To reduce operational complexity, Huaqiang Heavy Industry’s intelligent disc granulator integrates a sensor and PLC control system, enabling real-time monitoring and automatic adjustment of tilt angle and speed for more stable and efficient production.

III. Capacity Optimization: Achieving Dual Improvement in Efficiency and Quality

To fully realize the equipment’s potential, system optimization across the entire production process is necessary:

Raw Material Pretreatment is Fundamental: Ensure the material entering the granulator meets the required fineness (ideally 80 mesh or finer) and is absolutely uniformly mixed (mixing uniformity coefficient of variation CV < 5%). Uniform and fine powder is the core prerequisite for forming uniform granules.

Scientific Selection of Binders: Given the poor binding properties of pure organic raw materials, scientifically adding an appropriate amount of binder is key to improving granule strength (reducing breakage rate) and one-time pelletizing rate. The optimal type and addition ratio must be determined through experimentation based on the raw material composition.

Maintaining Optimal Equipment Condition: Regularly (e.g., every shift or daily) clean the inner wall of the disc and the scraper of any adhering material to prevent hardening of accumulated material that alters the disc’s internal contour and affects material rolling patterns. Check the scraper wear to ensure it effectively cleans the bottom of the disc.

Standardized Operations: For mature products, the optimal combination of tilt angle, rotation speed, and feed rate should be determined and solidified through testing to form a Standard Operating Procedure (SOP) to ensure consistency across different shifts.

Case Study: Significant Benefits of Optimization A large agricultural cooperative in China adopted a φ2.2-meter disc granulator and a complete optimization solution provided by Huaqiang Heavy Industry when producing organic-inorganic compound fertilizer. Through refined raw material crushing and mixing, precise control of granulation humidity, and strict regular cleaning and maintenance, the production line’s capacity steadily increased from the designed 5 tons/hour to 7 tons/hour without major equipment modifications, and the granule qualification rate (particle size range and strength) remained above 90% for a long time. This not only directly increased output value but also significantly reduced the unit product production cost and enhanced market competitiveness by reducing rework rate and energy consumption.

Conclusion: The Modern Value of Classic Equipment As a timeless classic piece of equipment, the disc granulator’s value continues to be renewed with the support of intelligent control and systematic process optimization. For the vast majority of small and medium-sized fertilizer production enterprises, a deep understanding of its working principle, mastery of the key parameters, and comprehensive production management will enable them to stably and efficiently produce high-quality fertilizer products with this “economical and practical” equipment, thus winning their own place in the market competition.

Positioning Disc Granulation within Integrated Manufacturing

The disc granulator is a key piece of professional fertilizer manufacturing equipment within specific production lines. Its primary role of disc granulator for shaping is often employed in an organic fertilizer production line or a bio organic fertilizer production line, where it gently forms spherical pellets from moist organic powders. However, its application is not universal. For the mainstream npk fertilizer production process, high-volume production is often achieved using a rotary drum granulator. Alternatively, a double roller press granulator is chosen for dry compaction granulation. The choice depends on the material’s characteristics and production goals.

A complete npk fertilizer production line typically begins with precise batching using a npk bulk blending machine and other fertilizer raw material processing machinery and equipment. If a wet granulation method similar to disc granulation is chosen for NPK, a larger-scale rotary drum is often used instead. Thus, a disc granulation production line is specifically advantageous for small-to-medium scale organic or compound fertilizer production where gentle agglomeration and flexibility are prioritized over extreme high capacity.

Therefore, understanding the strengths and ideal applications of the disc granulator allows manufacturers to strategically integrate it into a broader equipment portfolio, selecting the optimal granulation technology for each product type and scale within a diversified operation.