The NPK blender is the core mixing unit of the BB fertilizer blending production line. The production of BB fertilizer (Bulk Blending Fertilizer) is essentially a purely physical process—directly blending pre-formed single-element basic fertilizers such as large-particle urea, monoammonium phosphate, and potassium sulfate according to soil testing and formula data, without involving any chemical reactions. The entire BB fertilizer blending production line consists of a raw material storage and conveying system, a dynamic batching and metering system, an NPK blender, and an automatic packaging system. Basic fertilizers are fed into their respective buffer silos via bucket elevators. Dynamic cumulative metering is performed at the bottom of the silos by a variable frequency screw feeder according to a set formula, with metering error controlled within ±0.2%. The metered material then enters the NPK blender, which employs a double axis paddle structure. Under the high-speed stirring of the paddles at a special angle, the material is rapidly and uniformly mixed within 30 to 90 seconds. Addressing the characteristics of BB fertilizer raw materials—large particle size differences and varying specific gravities leading to segregation—the high-end production line is equipped with an anti-segregation feeding device. The entire line uses centralized PLC control, allowing for flexible and convenient formula switching—the same production line can produce dozens of different formulas on the same day. The NPK blender uses a gentle convection mixing principle, unlike the forceful crushing and stirring mode of organic fertilizers, achieving uniform mixing without compressing or breaking particles. The equipment occupies only 60 to 100 square meters, with an hourly output of 5 to 30 tons, saving more than 60% energy compared to traditional compound fertilizer production lines.

In the field of granulation, the organic fertilizer disc granulator (also known as the bio-organic fertilizer disc granulator) performs a completely different task. The main working component of this equipment is a tilted circular disc. Powdered organic fertilizer is conveyed to the pelletizing disc by a conveyor belt, where it continuously rolls under the combined action of centrifugal force, friction, and gravity, gradually forming spherical particles that eventually overflow from the edge of the disc. The disc granulator's outstanding advantage lies in its pelletizing rate—the pelletizing rate using an integral arc structure can reach over 93%. The disc's inclination angle is typically adjustable between 40 and 50 degrees, and the rotation speed can be set as needed. Another unique advantage of the organic fertilizer disc granulator is its room-temperature granulation characteristic—the entire pelletizing process is a purely physical operation, requiring no heating. This means that the functional microorganisms added during the granulation process will not be inactivated by high temperatures, and the activity of microorganisms in the finished pellets is fully preserved. The disc is lined with high-strength fiberglass, making it corrosion-resistant and wear-resistant; the bottom of the disc is reinforced with multiple radial steel plates, ensuring durability. The entire machine features a thickened, weighted, and sturdy base design, allowing for stable operation without the need for anchor bolts. In disc granulation production lines, this equipment is typically used in conjunction with a double axis mixer for organic fertilizers—powdered materials are first uniformly moistened with atomized water within the double axis mixer to form spherical nuclei, which are then fed into the pelleting disc for granulation.

BB fertilizer blending production lines and disc granulation production lines represent two distinct technical paths in fertilizer production: "blending" and "granulation." The former excels in flexible formulation, low investment, and rapid results, making it particularly suitable for agricultural input dealers transitioning to branded fertilizers and large-scale planting bases establishing their own fertilizer blending stations. The latter boasts advantages such as high granulation rate, uniform granules, and room-temperature operation that protects microbial activity, making it an ideal choice for organic fertilizer and bio-organic fertilizer production. The flexible combination of these two production lines allows companies to freely switch production modes based on raw material conditions and market demand, achieving full process coverage from powder granulation to finished product blending.