Dual-Function Production Line! NPK and Potassium Chloride Combined Production Line

 The NPK and potassium chloride combined production line is an integrated solution designed specifically for the "flexible production" needs of fertilizer companies. Through modular equipment configuration and process switching design, it can flexibly produce NPK compound fertilizer (multiple ratios) and potassium chloride granular fertilizer, achieving efficient capacity utilization of "one set of equipment, two products." It adapts to the diversified market demands of large-scale fertilizer production enterprises, significantly reducing equipment investment and site occupancy costs.

Core Design Logic and Full-Process Configuration of the Production Line

The production line is based on "raw material sharing, process differentiation, and equipment universality." It integrates key processes such as raw material pretreatment, precise batching, granulation, and post-processing. Through local equipment switching and parameter adjustments, it achieves rapid conversion between the two products. A single production line can achieve a capacity of 10-15 tons (NPK compound fertilizer) or 12-18 tons (potassium chloride granular fertilizer).

I. Raw Material Pretreatment and Sharing Unit: Laying the Foundation for Dual-Product Production

(I) Raw Material Storage and Precise Batching

Multi-Warehouse Storage System: Equipped with 6 raw material warehouses (total volume 150m³), storing urea, monoammonium phosphate, potassium chloride (main raw material), binder, trace elements, and functional additives respectively. The warehouse bodies are made of carbon steel with an anti-corrosion coating (compatible with the corrosiveness of potassium chloride). Vibrators and star-shaped unloaders are installed at the bottom to prevent raw material bridging and blockage.

Intelligent Batching Device: Employs a 6-channel variable frequency screw feeder, paired with a PLC control system. When producing NPK compound fertilizer, the proportions of nitrogen, phosphorus, potassium, and additives are precisely controlled according to the formula (batching error ≤ ±0.8%). When producing potassium chloride granular fertilizer, the amount of potassium chloride is increased separately (≥90%), reducing or closing other raw material channels to achieve rapid switching.

(II) Raw Material Pretreatment and Mixing

Crushing and Screening: Potassium chloride raw material is crushed to ≤2mm using a 400-type vertical crusher (to avoid large clumps affecting granulation). During NPK compound fertilizer production, other inorganic raw materials are simultaneously crushed to ≤3mm. A cyclone dust collector is used in the crushing process, achieving a dust recovery rate of 99%. After crushing, the raw materials are graded using a 1.2×4.0 meter drum screen; unqualified particles are returned for regrinding.

Twin-Shaft Mixer: A 60-type twin-shaft mixer is used. During NPK production, multiple components are thoroughly mixed (mixing uniformity error ≤2%). During potassium chloride production, only potassium chloride and a small amount of binder are mixed (addition amount 2%-5%). The mixer is equipped with a spray humidification device, and the moisture content of the raw materials is adjusted according to the product type (NPK: 25%-30%; potassium chloride: 18%-25%). II. Core Granulation Unit: Dual-Product Adaptability Design

(I) Granulation Machine Selection and Switching

Core Equipment: Two Φ2.0×8.0 meter rotary drum granulators (operating in parallel) are used to accommodate the granulation needs of two products. The inner wall of the drum is lined with wear-resistant ceramic plates (resistant to potassium chloride corrosion), and adjustable lifting plates are used. Process switching is achieved by adjusting the lifting plate angle and the drum speed.

Process Parameter Adjustment:

NPK Compound Fertilizer Production: Drum speed 12-15 r/min, material residence time 8-10 minutes, binder is sprayed through atomization to form 3-5mm rounded granules, granulation rate ≥92%;

Potassium Chloride Granular Fertilizer Production: Drum speed 10-12 r/min, extending the material residence time to 12-15 minutes, reducing the amount of binder, utilizing the crystallization characteristics of potassium chloride to assist in molding, particle size controlled at 2-4mm, granulation rate ≥90%. (II) Optimized Auxiliary Granulation

When producing potassium chloride, a pre-compression device is added to pre-compress the mixed potassium chloride raw materials into dense columns before feeding them into the rotary drum granulator, improving particle strength (to above 2.8 MPa) and avoiding pulverization caused by poor adhesion of potassium chloride.

When producing NPK, the pre-compression device is turned off, and the conventional rotary drum granulation process is used directly to ensure uniform fusion of multi-component raw materials.

III. Post-processing Unit: Branching Design Ensures Product Quality

(I) Drying and Cooling

Drying System: A single Φ2.2×20 meter drum dryer is used. Temperature adjustment achieves dual-product compatibility—NPK compound fertilizer is dried at 80-100℃, reducing the moisture content to below 12%; potassium chloride granular fertilizer is dried at 60-80℃ (to avoid high temperatures affecting crystallization stability), reducing the moisture content to below 8%. The dryer is equipped with temperature and humidity sensors to automatically adjust the hot air supply.

Cooling System: Adopting a "primary cooling + branched screening" design, a single Φ1.8×15m counter-current cooler is used to reduce the temperature of the dried granules to below 35℃. The granules are then branched through a three-way valve and conveyed to dedicated screening equipment.

(II) Grading and Finished Product Processing

NPK Compound Fertilizer: After screening using a Φ1.5×6.0m double-layer drum screen (3-5mm sieve aperture), unqualified granules are returned to the raw material mixing stage.

Potassium Chloride Granular Fertilizer: After screening using a Φ1.2×4.0m single-layer vibrating screen (2-4mm sieve aperture), 0.1% anti-caking agent (such as potassium silicate) is sprayed to improve moisture resistance.

IV. Finished Product Storage and Packaging Unit: High-Efficiency Output Switching

Finished Product Warehouse: Equipped with 3 x 100m³ finished product warehouses (2 for NPK compound fertilizer, 1 for potassium chloride granular fertilizer), all featuring a sealed design with dehumidification and ventilation devices. The potassium chloride warehouse has a dedicated anti-corrosion treatment to prevent corrosion.

Packaging System: Shares 2 dual-station automatic packaging scales, allowing for specification switching by adjusting measurement parameters (NPK supports 25kg/50kg, potassium chloride supports 20kg/50kg). Measurement error ≤ ±0.2kg, packaging speed reaches 120 bags/hour, and a conveyor belt enables rapid transfer of finished products.

V. Environmental Protection and Intelligent Control Unit: Stable Green Production

(I) Environmental Protection

Dust Treatment: Each stage is equipped with a pulse dust collector (total processing air volume 20,000 m³/h). Corrosion-resistant dust collector materials are used during potassium chloride production, with dust emission concentration ≤10 mg/m³.

Wastewater Treatment: Washing wastewater is treated by an oil separator and sedimentation tank before being recycled for raw material humidification, achieving zero wastewater discharge.

(II) Intelligent Control

Integrated PLC central control system, preset with two production modes: NPK and potassium chloride. One-click switching of key parameters such as batching ratio, granulation speed, and drying temperature is supported, along with automatic fault alarms and data recording.

Key equipment (granulator, dryer) is equipped with safety interlock devices to ensure stable operation during production transitions.

Core Advantages and Application Value of the Production Line

Flexible and High-Efficiency Production: One set of equipment enables the production of two mainstream fertilizers, reducing transition time to less than 2 hours, significantly reducing equipment investment and site costs, and allowing for rapid capacity adjustments to adapt to market demand fluctuations. Dual Guarantee of Product Quality: Targeted process design and parameter optimization ensure that NPK compound fertilizer has uniform nutrients and rounded granules, while potassium chloride granular fertilizer has high strength and moisture resistance, both meeting national standards.

Energy Saving, Environmental Protection, and Low Cost: Equipment sharing rate exceeds 70%, reducing energy consumption by 18% compared to two separate production lines; dust recovery and wastewater recycling reduce material waste and environmental pollution.

Enhancing Efficiency and Versatility in Fertilizer Manufacturing

This innovative NPK and potassium chloride combined production line exemplifies a strategic approach to modern fertilizer manufacturing. It maximizes asset utilization and operational flexibility, allowing producers to efficiently respond to changing market demands from a single facility.

The line's core function as an npk fertilizer production line highlights advanced npk fertilizer production technology. Its intelligent design centers around the npk granulation machine technology. Key components include a high-precision npk bulk blending machine for formula preparation and the npk fertilizer granulator machine (a npk fertilizer granulator) for shaping the mixture into granules. The entire npk fertilizer manufacturing process—from batching to granulation and coating—is integrated and optimized within this single, adaptable npk fertilizer production process, demonstrating how modular design can create a versatile and cost-effective production ecosystem.

Ultimately, this solution empowers fertilizer companies to diversify their product portfolio without duplicating infrastructure, securing a competitive edge through agility and efficiency.