As the core granulation equipment in an organic fertilizer production line, the structural design of a rotary drum granulator directly impacts granulation efficiency and product quality. Its overall design is centered around “efficient granulation, stable conveying, and adaptability to the characteristics of organic fertilizers.”

The rotary drum granulator‘s core working component is an inclined rotating drum, welded from steel plates. The inner wall is lined with a wear-resistant lining to prevent abrasion by humic acid and other components in the organic fertilizer raw materials, while also enhancing material friction to aid granulation. The drive system offers both constant and variable speed options.

The constant speed option is suitable for large-scale production with stable raw materials, while the variable speed option (8-15 rpm) can be adjusted to suit different raw materials: reducing the speed to prevent sticking when the liquid content is high, while increasing the speed to promote compact granules when the liquid content is low.The rotary drum granulator drum inclination angle is a critical parameter, typically 3-10 degrees. A too small angle causes the material to remain in the drum for too long, leading to agglomeration or oversized granules. A too large angle results in rapid material flow, insufficient granulation time, and loose granules. A 50-100mm high retaining ring is installed at the feed end to prevent loose powder from flowing back. The height of the retaining ring at the discharge end is adjustable. It can be raised to extend retention time when larger pellets are needed, and lowered or replaced with a spiral discharge ring for faster discharge. The blade angle matches the rotational speed, ensuring a uniform feed to the screen and preventing clogging.

The integrated cylindrical screen is key to finished product screening. Its aperture is customized to meet organic fertilizer requirements (2-5mm). Rotating synchronously with the drum, qualified pellets are discharged while unqualified, large particles are returned for reprocessing, achieving an integrated “granulation-screening” process. The flexible binder injection system allows for pre-injection, suitable for highly absorbent raw materials such as straw. Instantaneous injection allows for precise moisture control to prevent over-wetting. Both methods are equipped with metering pumps to ensure precise dosage (10%-15% of the total raw material) and guarantee pellet formation efficiency.

Organic fertilizer production line equipment promotes agricultural production. Organic fertilizer is of great significance to protecting a healthy ecological environment and human health. Organic fertilizer production lines have abundant raw material resources, a wide variety, and a vast quantity. Commercial organic fertilizer processed by organic fertilizer equipment is an important source of fertilizer for agricultural production. Wherever there is agriculture and animal husbandry, there is a source of organic fertilizer and a need for organic fertilizer equipment. Urban organic household waste can also serve as a fertilizer source for organic fertilizer production lines.

The more developed agriculture and animal husbandry, the more abundant the organic fertilizer resources. Not only in China, but also in countries such as the United States, Germany, Africa, and Australia, there is an increasing emphasis on organic fertilizer. Therefore, organic fertilizer production lines and processing equipment are particularly important. Green manure, human waste, feces, biogas, and waste manure are all raw materials for organic fertilizer production. Organic fertilizers are mainly divided into feces, urine, compost, cake fertilizer, peat, soil, municipal waste, and miscellaneous manure. In addition to providing organic carbon nutrients such as nitrogen, phosphorus, and potassium, organic fertilizers also provide a considerable amount of medium and trace elements, as well as organic nutrients such as amino acids, nucleic acids, sugars, and vitamins. Because organic fertilizers contain a relatively complete range of nutrients and are completely non-toxic, harmless, and pollution-free natural substances, they provide the necessary conditions for producing high-yield, high-quality, and pollution-free green food.

Organic fertilizers produced by organic fertilizer production lines are an important way to achieve high and stable crop yields. The yields of grain crops such as wheat and corn increase with increased fertilizer application, highlighting the advantages of organic fertilizers and their irreplaceable nature. Compared to chemical fertilizers, people are choosing organic fertilizers accordingly. Professional organic fertilizer production line equipment can reduce fertilizer production costs, effectively lower agricultural production costs, and minimize environmental pollution. Organic fertilizer production line equipment meets the requirements of sustainable development in modern agriculture.

Organic fertilizer production lines use scientific processes to transform agricultural and livestock waste into high-quality fertilizer, achieving resource recycling. The entire production process revolves around four core steps: raw material processing – composting – forming – packaging, and each step directly impacts fertilizer quality.

The first step is raw material pretreatment. The production line collects raw materials such as livestock manure, straw, and mushroom residue, and uses screening equipment to remove impurities such as stones and plastic to prevent them from affecting subsequent processes. Next, a crusher is used to pulverize the straw and other coarse fiber materials to a particle size of 5-10mm. The material is then mixed with livestock manure in a ratio of approximately 3:7. A small amount of fermentation inoculant is added, adjusting the carbon-nitrogen ratio to 25:1-30:1 and controlling the moisture content to 50%-60%, laying the foundation for fermentation and composting.

The second step is fermentation and composting. The mixed raw materials are transported to the fermentation workshop and stacked in windrow or tank-type fermentation equipment. During the fermentation process, a compost turning machine regularly turns the material to ensure adequate oxygen and regulate the temperature. The entire fermentation cycle lasts approximately 20-30 days. After composting, the material transforms into a dark brown, odorless humus. It then passes through a cooling device to a temperature below 30°C to prevent nutrient loss during subsequent processing.

The third step is further processing and shaping. The cooled composted material is first crushed to a particle size of 2-3mm in a fine grinder. It is then mixed with a small amount of auxiliary materials such as bentonite and humic acid in a mixer to enhance the fertilizer’s stability. The material then enters the granulation stage, where a rotary drum or disc granulator physically agglomerates the material into 2-5mm granules. The granules are then dried (controlled at 60-80°C) to reduce moisture to below 15%, cooled in a cooler, and screened to separate unqualified particles. The fine powder is then returned to the granulator for reuse.

The finished product is then packaged. Qualified pellets are transported to the packaging workshop, where an automatic packaging machine weighs and seals them into 25kg or 50kg packages, producing finished organic fertilizer.

In short, the organic fertilizer production line, through standardized and mechanized full-process control, efficiently transforms waste into high-quality fertilizer, contributing to environmental protection while providing green nutrients for agriculture.