As a core piece of equipment in fertilizer production lines, the granulator’s operating status directly affects the efficiency and economic benefits of the entire production line. Mastering scientific fault diagnosis methods and systematic maintenance strategies can significantly extend equipment life, reduce unplanned downtime losses, and create continuous and stable production value for enterprises.

I. Common Fault Phenomena and Precise Diagnostic Procedures

1. Granulation Quality Issues

Symptoms: Uneven granules, insufficient strength, decreased pelletizing rate

Diagnostic Steps:

Check raw material ratio: Verify the accuracy of nitrogen, phosphorus, potassium, and binder proportions.

Check raw material moisture content: Take samples to determine moisture content; the normal range should be 25%-35%.

Analyze raw material fineness: Use a sieve analyzer to ensure that more than 80% of the raw material passes through an 80-mesh sieve.

Check granulation parameters: Verify key parameters such as disc tilt angle (35°-45°), rotation speed (20-30 rpm), etc.

Solutions:

If the raw material moisture content is abnormal, immediately adjust the drying or humidification system.

If the formula ratio is unbalanced, recalibrate the automatic batching system.

If the granulation parameters are improper, reset them according to the standard operating manual.

2. Equipment Mechanical Failures

Symptoms: Abnormal vibration, bearing overheating, abnormal noise in the transmission system

Rapid Diagnostic Methods:

Vibration Detection: Measure the bearing housing vibration using a vibration meter. Normal vibration should be less than 4.5 mm/s.

Temperature Monitoring: Detect the bearing temperature using an infrared thermometer. If it exceeds 80℃, immediate action is required.

Sound Localization: Use a stethoscope to pinpoint the source of abnormal noise.

Typical Case: A fertilizer plant’s granulator suddenly experienced severe vibration. Testing revealed:

Main bearing vibration reached 8.2 mm/s (exceeding the standard)

Bearing temperature reached 92℃ (severely exceeding the standard)

Disassembly and inspection revealed severe wear on the bearing rollers.

Root Cause: Lubrication system failure leading to insufficient lubrication in the bearing.
      

II. Systematic Maintenance and Upkeep System

Daily Maintenance Standards (Performed every shift)

Cleaning and Inspection:

Remove accumulated material from the inner wall of the granulation disc

Clean the screen blockage

Inspect the scraper wear

Lubrication Management :

Check oil levels at all lubrication points

Replenish with dedicated high-temperature grease

Record lubrication time and amount

Tightening Check:

Check anchor bolt tightness

Verify transmission component connection status

Confirm safety protection devices are intact

Preventive Maintenance Plan Weekly Maintenance Focus:

Thoroughly clean the equipment interior

Inspect wear parts for vulnerable components

Calibrate measuring instrument accuracy

Monthly Maintenance Items:

Comprehensive bearing inspection: clearance measurement, seal inspection

Transmission system verification: gear meshing clearance adjustment

Electrical system inspection: motor insulation test, wiring tightening

Quarterly Deep Maintenance:

Comprehensive equipment disassembly and inspection

Flaw detection of major components

Control system software upgrade

III. Intelligent Maintenance Technology Application Online Monitoring System Construction Sensor Deployment:

Vibration sensors: key bearing locations

Temperature sensors: motors, bearings, reducers Current Sensor: Main Drive Motor

Data Acquisition and Analysis:

Establish Equipment Health Database

Set Early Warning Thresholds

Achieve Trend Analysis and Prediction

Predictive Maintenance Practices Successful Case: A fertilizer company in Zhejiang Province, through the installation of an online monitoring system:

Provided early warning of main bearing failure 3 weeks in advance

Avoided 72 hours of unplanned downtime

Saved 150,000 yuan in maintenance costs

Reduced production loss by 300 tons

IV. Spare Parts Management Optimization Strategy Key Spare Parts Classification Management Category A Spare Parts (Key Spare Parts):

Main Drive Bearing

Gear Reducer

Pelletizing Disc Liner Inventory Strategy: Maintain 1-2 sets of safety stock

Category B Spare Parts (Important Spare Parts):

Scraper Assembly

Sealing Sleeves

Electrical Components Inventory Strategy: Maintain 3-6 months’ worth of usage

Category C Spare Parts (Common Spare Parts):

Standard Fasteners

Ordinary Sealing Rings

Lubricating Grease Inventory Strategy Omitted: Procurement on Demand

Supplier Management

Establish a list of qualified suppliers

Sign a rapid response agreement

Implement supplier performance evaluation  
      

V. Personnel Training and Technology Transfer

Operator Capacity Building

Basic Training:

Equipment Structure and Principles

Standard Operating Procedures

Daily Inspection Points

Skills Enhancement:

Fault Diagnosis Methods

Emergency Handling Procedures

Maintenance Techniques

Establish a Knowledge Management System

Compile a Fault Case Database

Produce Maintenance Video Tutorials

Establish a Technical Exchange Platform

VI. Economic Benefit Analysis

After implementing systematic maintenance management:

Equipment failure rate reduced by 60%

Average repair time shortened by 45%

Spare parts inventory cost reduced by 30%

Equipment service life extended by 40%

Annual comprehensive benefits increased by 25%

Holistic Maintenance for Diverse Granulation Systems

The rigorous maintenance principles outlined are universally applicable but must be adapted to the specific fertilizer production machine technology employed. Within the npk fertilizer manufacturing process (or the manufacturing of npk fertilizer), different granulation technologies are used. For the common wet fertilizer granulation processes involving a rotary drum granulator, maintenance focuses on liners, bearings, and the drive system. For dry granulation, a roller press granulator production line utilizing a fertilizer compactor requires specific attention to roller surface integrity, hydraulic pressure, and bearing temperature, as this fertilizer compaction method relies on high mechanical pressure.

Similarly, in an organic fertilizer disc granulation production line, maintenance revolves around the disc, scraper, and gearbox. The upstream fertilizer processing machine, such as a windrow composting machine providing feedstock, also has its own maintenance schedule. Therefore, a comprehensive strategy is required for the entire suite of fertilizer production machine units. Predictive maintenance and spare parts management for the core granulator—whether for fertilizer granules compaction or wet agglomeration—are critical investments that protect the substantial capital tied up in the npk manufacturing process and ensure uninterrupted, profitable operation.

Ultimately, viewing maintenance not as a reactive cost but as a proactive component of operational strategy is what transforms equipment management into a source of competitive advantage, ensuring reliability across all fertilizer production technologies.

The maintenance management of granulators is a systematic project that requires the organic combination of traditional experience and modern technology. By establishing a scientific fault diagnosis system, implementing refined maintenance, and applying intelligent monitoring technology, enterprises can not only effectively reduce downtime losses but also transform equipment management from a “cost center” to a “value creation center.” It is recommended that enterprises formulate appropriate maintenance strategies based on their own actual situation, and continuously optimize and improve them to ultimately maximize the value of equipment throughout its entire life cycle, providing a solid guarantee for the stable production and sustainable development of enterprises.

In fertilizer production enterprises, the production line is a complex system composed of a series of equipment such as granulators, crushers, compost turners, and screening machines. Scientific and systematic maintenance is not only the foundation for extending equipment lifespan but also a key means to reduce unplanned downtime and lower overall operating costs. Establishing an efficient and feasible maintenance system has become an important guarantee for fertilizer production enterprises to enhance competitiveness and ensure continuous production.

Core Equipment Maintenance Points and Practical Suggestions As the core equipment in fertilizer production, the granulator’s operating status directly affects product output and quality. For common drum granulators, the wear of the liner plates needs to be closely monitored. Rubber or stainless steel liners, subjected to long-term material friction, will gradually decrease in thickness. When the wear exceeds 3mm, they should be replaced promptly; otherwise, material sticking to the wall and a decrease in pelletizing rate may occur. Maintenance of the transmission system is equally crucial. Gears should be lubricated weekly, and meshing clearance checked monthly to prevent increased equipment vibration due to gear wear. For roller press granulators, it is necessary to regularly clean the material adhering to the roller surface and check the bearing operating temperature quarterly to prevent bearing damage due to overheating.

The key maintenance focus for crushers is on the blades and screens. The chain blades of chain crushers need to be checked for tightness regularly. When the cutting edges are severely worn, they should be sharpened or replaced promptly to ensure uniform material crushing. The screens of semi-wet material crushers should be disassembled and cleaned monthly to prevent material blockage from affecting the output particle size and equipment capacity.

Compost turners are crucial in the organic fertilizer fermentation process. Their hydraulic system and auger blades need to be checked carefully. The hydraulic oil should be changed regularly, and the hydraulic system kept clean. The auger blade bolts should be checked for tightness to prevent loosening and falling off during operation, which could cause equipment damage.

Establishing a systematic maintenance management system is essential. In addition to specific equipment maintenance, establishing a scientific maintenance management system is the systematic foundation for ensuring the long-term stable operation of equipment.

Systematized Daily Inspections: A clear inspection checklist should be established. Before starting the machine each day, check the oil levels at all lubrication points, the tightness of bolts in key areas, and the integrity of safety devices. Clean any residual materials inside the equipment weekly to prevent long-term accumulation of corrosive materials that could damage the equipment.

Standardized Periodic Maintenance: A comprehensive overhaul is recommended monthly to systematically identify potential fault points, such as aging electrical wiring, worn transmission components, and failed seals, thus implementing preventative maintenance.

Professional Personnel Training: Operators and maintenance personnel must undergo systematic training to be familiar with the equipment’s structure, principles, and safe operating procedures, preventing equipment damage caused by improper operation. Strict adherence to procedures is crucial, especially for critical operations such as equipment start-up, shutdown, and load adjustment.

Building a Long-Term Support System: Equipment maintenance is not just about daily operations; a long-term support mechanism is essential. It is recommended that manufacturers establish stable partnerships with equipment suppliers. For example, Zhengzhou Huaqiang Heavy Industry provides lifetime maintenance services and spare parts supply support to its customers. This cooperative model ensures timely technical support in the event of equipment failure.

Furthermore, companies should establish a critical spare parts inventory system. Maintaining adequate inventory of vulnerable parts and critical components (such as liners, cutting tools, and bearings) allows for rapid replacement in case of malfunctions, minimizing downtime losses. Simultaneously, establishing equipment maintenance records documents each maintenance session, including the details of replaced parts and operational status, providing data support for equipment management.

Proactive Maintenance Across the Fertilizer Production Line

The principles of systematic maintenance apply to every piece of equipment within a complete npk fertilizer line or organic production system. This includes upstream fertilizer raw material processing machinery and equipment like crushers and npk blending machine units, which require regular blade and bearing checks. In the core npk fertilizer production process, the granulator demands the most attention. For a disc granulation production line, maintenance focuses on the disc granulator itself, particularly the disc granulator for shaping plate wear and gearbox lubrication.

For an alternative roller press granulator production line centered on a double roller press granulator, maintenance shifts to monitoring roller surface wear, bearing temperatures, and hydraulic system integrity. Similarly, in an organic system fed by a windrow composting machine, the turner’s moving parts require scheduled care. Implementing a rigorous maintenance schedule for this entire suite of professional fertilizer manufacturing equipment—from the npk bulk blending machine to the final granulator—is what ensures high availability, consistent product quality, and protects the substantial capital investment in the production line.

Therefore, maintenance is not a cost center but a strategic function. It directly safeguards production capacity, operational efficiency, and profitability by preventing catastrophic failures and ensuring every component of the integrated manufacturing system performs reliably.

Conclusion: The maintenance of fertilizer production equipment is a systematic project requiring comprehensive implementation by enterprises, from awareness and systems to execution. Refined and standardized equipment management not only extends equipment lifespan and reduces maintenance costs but also ensures production continuity by minimizing unplanned downtime, ultimately improving overall operational efficiency and market competitiveness. In the entire equipment lifecycle management process, a scientific maintenance strategy is a crucial cornerstone for achieving stable production, controllable costs, and safe operation.

Driven by the dual goals of carbon peaking, carbon neutrality, and green development policies, the fertilizer industry is facing a profound green transformation. “Zero emissions” and “low energy consumption” are no longer merely policy constraints, but intrinsic requirements for enterprises to enhance competitiveness and achieve sustainable development. Building a systematic environmental compliance system requires coordinated efforts in two aspects: comprehensive treatment of waste gas, wastewater, and waste residue, and energy-saving optimization of production processes.

Waste Gas Treatment: From “Harmlessness” to “Resource Utilization” During fertilizer production, processes such as raw material fermentation and drying easily generate irritating and harmful gases such as ammonia and hydrogen sulfide. Traditional open-loop treatment methods can no longer meet increasingly stringent emission standards, necessitating a systematic solution of “closed collection + tiered purification.”

Taking the organic fertilizer production line designed by Zhengzhou Huaqiang Heavy Industry as an example, by establishing a fully enclosed fermentation workshop, waste gas is collected centrally and first recovered through a condensation tower to achieve resource reuse; the remaining gas then enters a biofilter, where microbial metabolism degrades odorous substances such as hydrogen sulfide. This process not only reduces exhaust gas emission concentrations far below the “Odor Pollutant Emission Standard” (GB 14554-93), but also lowers nitrogen loss through ammonia recovery, achieving both environmental and economic benefits. Simultaneously, air curtains and negative pressure systems at workshop entrances and exits, combined with atomizing deodorization devices, significantly improve the factory area and surrounding environment.

Wastewater and Solid Waste: Recycling for “Zero Waste”

Wastewater from fertilizer production mainly originates from raw material washing, equipment cooling, and workshop rinsing. To achieve “zero emissions,” a graded treatment and recycling water resource management system needs to be established: suspended solids are removed through sedimentation and flotation, followed by biochemical treatment to degrade organic matter. The treated water can be used for raw material humidification, granulation humidification, or equipment cooling, forming an internal water cycle within the factory and significantly reducing the amount of fresh water required.

Solid waste can also be converted into resources. Screen residues and insufficiently strong particles generated during production can be crushed and reused in the granulation process; some fine powder can also be sold as a horticultural substrate or soil conditioner. This not only reduces the pressure of solid waste disposal but also improves the comprehensive utilization rate of raw materials and lowers production costs.

Low Energy Consumption Optimization: A Dual Approach of Technology and Management

Reducing energy consumption requires starting from the source—equipment selection and process design. In the granulation stage, using a rotary drum granulator equipped with a variable frequency control system allows for automatic speed adjustment based on material conditions, avoiding energy waste caused by over-engineering and saving over 30% more electricity than traditional fixed-speed equipment. For heat-sensitive materials, “room-temperature forming” processes such as roller pressing can be used, eliminating the drying stage and directly reducing heat consumption.

Furthermore, establishing an intelligent energy monitoring platform collects real-time data on electricity, water, and gas consumption at each stage. Analysis identifies energy efficiency bottlenecks, providing a basis for continuous improvement. Regular equipment maintenance and thermal system optimization are conducted, such as recovering waste heat for raw material preheating, further tapping into energy-saving potential.

Building a Long-Term Environmental Management System

Environmental compliance is not a one-time investment but a dynamic process requiring long-term commitment. Enterprises should establish internal environmental management systems, clarify responsibilities at each stage, and conduct regular emission testing and audits. Simultaneously, maintaining technical collaboration with equipment suppliers and leveraging their experience allows for rapid process optimization. For example, partnering with suppliers like Huaqiang Heavy Industry, which possess comprehensive solution capabilities, provides access to full-cycle services from engineering design and equipment integration to operational support, significantly reducing the technical risks and time costs of addressing environmental requirements independently.

Closed-Loop and Efficient Organic Fertilizer Production

Achieving the “zero emissions” and “low energy consumption” goals requires an integrated approach within the organic fertilizer manufacturing system. This begins with controlled aerobic fermentation, managed efficiently by equipment like a large wheel compost turning machine or a chain compost turning machine, within enclosed facilities to manage emissions. The cured compost then enters a dedicated organic fertilizer production line. The core stage of organic fertilizer production granulation offers several technology paths, each with different energy profiles.

For energy-efficient shaping, a traditional organic fertilizer disc granulation production line using an organic fertilizer disc granulation machine is common. To save space and process steps, a new type two in one organic fertilizer granulator that combines mixing and granulation can be effective. More complex organic fertilizer combined granulation production line setups may integrate multiple methods. The selection of granulation technology directly impacts the need for subsequent drying, a major energy consumer, and thus must be aligned with the overall environmental strategy of the organic fertilizer manufacturing operation.

Therefore, a truly sustainable organic fertilizer plant integrates emission control from the composting stage with energy-conscious equipment selection in the granulation and drying stages, creating a holistic production system that is both environmentally compliant and economically viable.

Conclusion: Environmental Compliance is the Cornerstone of High-Quality Development. Facing the era’s challenge of green manufacturing, fertilizer producers should deeply integrate environmental requirements into their entire production and operation process. Achieving “zero emissions” through systematic waste gas, wastewater, and waste residue treatment, and reducing energy consumption through energy-saving technologies and refined management, not only meets regulatory requirements and mitigates operational risks but also improves resource efficiency, cultivates a green brand image, and ultimately gains a long-term development advantage in the industry’s transformation. Environmental compliance has become an essential path for fertilizer companies to move from “compliant survival” to “green competitiveness.”

In compound fertilizer production, granulation technology is a key factor determining product quality, production efficiency, and overall cost. Currently, rotary granulation and roller granulation are the two mainstream technologies in the market, each with its own applicable scenarios and technological advantages. How can enterprises scientifically choose the right technology based on their own needs? The following analysis examines the technology from multiple dimensions, including technical characteristics, applicable conditions, and economic benefits.

Roller Granulation: A Sound Choice for Large-Scale Production

Roller granulation technology’s core advantages are “high pelletizing rate” and “large-scale production.” Its process principle involves using a rotating drum to thoroughly mix and roll the material and binder, gradually forming uniform particles. The pelletizing rate of this technology can typically reach over 95%, with a production capacity ranging from 1 to 20 tons/hour, making it particularly suitable for large-scale continuous production lines.

In terms of raw material adaptability, rotary granulation has good compatibility with various nitrogen, phosphorus, and potassium raw materials and can be used with common basic fertilizers such as urea, ammonium sulfate, and diammonium phosphate (DAP). The resulting granules have high strength, good sphericity, and excellent physical stability, making them suitable for long-term storage and long-distance transportation. Therefore, they are widely used in the large-scale production of NPK compound fertilizers and general-purpose compound fertilizers.

Taking Zhengzhou Huaqiang Heavy Industry’s rotary drum granulator as an example, its special rubber liner design enables automatic cleaning and removal of lumps and nodules, significantly reducing the problem of clumping and agglomeration, and lowering downtime maintenance frequency and manual cleaning costs. For large fertilizer companies pursuing stable mass production and high product standardization, rotary drum granulation remains the preferred solution due to its mature technology and reliable operation.
     

Roller Press Granulation: A New Path to Energy Saving and Flexibility

Roller press granulation technology highlights “room temperature molding” and “energy saving and consumption reduction.” This process directly presses powdered raw materials into shape through high-pressure extrusion by two rollers, eliminating the need for subsequent drying. Overall energy consumption can be reduced to about 60% of that of rotary drum granulation.

In terms of raw material processing, roller press granulation has no special requirements for material particle size and is particularly suitable for heat-sensitive raw materials and the addition of trace elements. The minimal temperature fluctuations in materials during production prevent the decomposition and loss of nutrients due to high temperatures, allowing for the precise incorporation of trace elements such as boron, iron, zinc, and copper. This makes it suitable for producing various specialized and functional compound fertilizers.

This technology also offers a production capacity flexibility of 1-20 tons/hour, but its relatively lower equipment investment and simpler process make it more popular with small and medium-sized fertilizer companies or manufacturers focusing on product customization. For example, a Malaysian customer chose Huaqiang Heavy Industry’s roller granulation production line, which was designed specifically for the local hot and humid climate, enabling rapid installation, commissioning, and stable operation, effectively meeting the regional market’s personalized needs for specialty fertilizers.
          

Key Considerations for Enterprise Selection

When choosing between these two technologies, companies should conduct a systematic evaluation from the following four dimensions:

Product Type and Raw Material Characteristics

If the main products are general-purpose compound fertilizers and large-scale standardized products, and the raw materials do not contain heat-sensitive components, roller granulation is more suitable. For producing specialized fertilizers containing heat-sensitive materials such as trace elements and humic acid, roller granulation better ensures the stability of active ingredients.

Capacity and Scale Requirements: Drum granulation is suitable for continuous, high-volume production with a high capacity ceiling and strong production line scalability; roller pressing, on the other hand, adapts to flexible production modes of multiple varieties and small batches, especially suitable for order-based and differentiated fertilizer products.

Energy Consumption and Overall Cost: Roller pressing eliminates the drying process, resulting in significant advantages in electricity and heat consumption, making it suitable for regions with high energy costs. While the initial investment for drum granulation may be higher, unit costs can still be controlled at a low level in ultra-large-scale production.

Maintenance and Operation: Drum granulation equipment requires regular cleaning and maintenance, but current automated cleaning technologies have significantly reduced the manual burden; roller pressing has a relatively simple mechanical structure and low maintenance frequency, but it places certain demands on roller wear, requiring careful material selection and maintenance.

Diverse Granulation Technologies for Fertilizer Production

This comparative analysis highlights the strategic choice between wet and dry granulation paths within fertilizer production machine technology. The rotary drum granulator represents the standard for large-scale, high-volume wet agglomeration in the npk fertilizer manufacturing process. In contrast, the roller press granulator production line operates on the principle of dry fertilizer granules compaction, where a fertilizer compactor applies high pressure, eliminating the need for drying. This method is a distinct and efficient pathway within the broader npk manufacturing process.

The selection of granulation equipment is a fundamental decision in designing fertilizer manufacturing plant equipment. While drum and roller press are primary for NPK, other technologies serve niche markets. For organic production, an organic fertilizer disc granulation production line offers gentle shaping. For small-scale or specialized pellet production, a flat die pelleting machine provides a compact extrusion solution. Thus, a comprehensive fertilizer equipment supplier must master this entire spectrum of technologies to provide truly customized solutions based on client-specific raw materials, capacity, and product goals.

Ultimately, there is no single “best” technology. The optimal choice is the one that aligns with the specific economic, agronomic, and operational parameters of the production facility, ensuring both product quality and long-term profitability.

Conclusion: In summary, drum granulation and roller pressing are not simple substitutes, but rather complementary technologies based on different product strategies and production conditions. For large enterprises producing general-purpose fertilizers, roller granulation is a solid and efficient cornerstone; for small and medium-sized enterprises focusing on specialty fertilizers, roller pressing offers an energy-saving and flexible growth path. In today’s era of green manufacturing and precision agriculture, scientific selection not only affects corporate profits but also impacts the final efficacy and sustainable competitiveness of fertilizer products. It is recommended that companies conduct pilot-scale trials before making decisions, combining their own raw materials, market conditions, and operational goals to make the most suitable technological investment.