Ball Shaping Machine

Ball Shaping Machine

The spheronizer—also known as a granule shaper or polisher—is specialized post-processing equipment designed to refine the shape and finish of organic fertilizer, compound fertilizer, and various powder-based granules. It serves as a finishing unit that rounds and polishes cylindrical or irregular granules produced by granulation systems such as flat-die extruders, ring-die granulators, disc granulators, and rotary drum granulators. By rolling cylindrical granules into spheres in a single pass, the machine ensures a high pelletizing rate, excellent structural strength, and an aesthetically pleasing, practical finish; it is the ideal solution for producing spherical organic (or bio-organic) fertilizer granules.

In the production of organic and compound fertilizers, granules discharged from granulators are often cylindrical or irregular, featuring rough surfaces, burrs, poor sphericity, insufficient strength, and limited flowability—factors that negatively impact commercial value and market competitiveness. The spheronizer addresses these industry challenges by utilizing the combined effects of physical friction and centrifugal rolling to transform irregular raw granules into smooth, uniform spheres, thereby significantly enhancing the product's visual quality. Capable of achieving a pelletizing rate exceeding 95%, the machine improves sphericity by 30%–50% and boosts compressive strength, making it a crucial piece of auxiliary equipment for upgrading the quality of commercial organic fertilizers.

Designed for continuous 24-hour operation, the spheronizer is user-friendly, allowing general workers to master its operation with minimal training. It has become an indispensable "finishing specialist" in the production of organic, compound, and bio-organic fertilizer granules, serving as a vital link between the granulation and drying stages.

Equipment Structure And Composition

The circular throwing machine mainly consists of the following parts:

Throwing cylinder body: This is the core component of the throwing machine, usually cylindrical or conical, with special throwing structures designed inside, such as throwing plates, throwing disks, etc., to promote the rolling of materials and the formation of round particles.

Drive system: including motor, reducer, and transmission device, providing stable rotational power for the throwing cylinder body.

Humidification/Adhesive System: Used to add an appropriate amount of water or adhesive to materials to help them bond and form round particles.

Feeding and discharging system: including feeding and discharging ports, as well as corresponding control devices, to ensure uniform feeding of materials and smooth discharge of round particles.

Control system: including PLC or microcomputer control system, used to monitor and adjust the operating parameters of the polishing machine, such as speed, humidity, time, etc., to achieve automated operation.

Safety protection system: including overload protection, emergency stop and other safety devices to ensure the safety of equipment and operators.

Overall Structure and Core Components

The spheronizer features a modular, integrated design with a clear structure that facilitates easy assembly and disassembly. The machine comprises five main systems:

(I) Frame Assembly: As the frame supports the transmission and rotating components—bearing significant loads—it is constructed from welded high-quality carbon steel channel sections and undergoes rigorous quality control. The frame is robust and durable; certain models feature a weighted base, allowing for stable operation without the need for anchor bolts.

(II) Spheronization Cylinder and Polishing Disc: These are the core working components, consisting of the cylinder body, a high-speed rotating polishing disc, and an inner lining. Both the disc and cylinder are made of high-manganese steel that has been thickened and heat-treated (quenched and tempered); their surfaces undergo a special wear-resistant treatment to ensure high hardness and resistance to wear and corrosion. The inner walls are typically lined with wear-resistant steel plate, high-molecular-weight polyethylene, or stainless steel, and feature detachable scrapers to prevent wet material from temporarily sticking to the walls. Polishing disc diameters range from 800mm to 1200mm. The equipment supports single-stage, two-stage, or three-stage tandem disc configurations; multi-stage processing ensures the final granules are uniform in size, dense, and smooth.

(III) Transmission System: Comprising the main motor, pulleys, V-belts, a large drive wheel, and the main shaft. The motor utilizes a flexible belt drive to ensure smooth startup, effectively cushioning impact forces and extending the equipment's service life. The system includes a variable frequency drive (VFD) for speed control, allowing rotational speed to be adjusted flexibly based on material characteristics.

(IV) Liquid Spraying Device: Features a precision atomization design that evenly sprays small amounts of water or binder to assist in granule shaping while minimizing dust generation. The equipment is designed to integrate with this spraying system.

(V) Grading Screen and Discharge Adjustment: An adjuster is located at the polishing disc outlet to control the discharge opening size and, consequently, the granule specifications. The grading screen is easily interchangeable, enabling precise sorting of granules by size. In addition, an automatic material-clearing plate is installed beneath the main disc to remove material adhering to the disc's underside during production; this significantly extends the equipment's service life and saves on labor.

Applicable Fields and Industry Coverage

This spheronizer has a wide range of applications. In the organic fertilizer sector, it is used to reshape—via secondary rounding—cylindrical or irregular granules initially produced from raw materials such as livestock and poultry manure (chicken, pig, cattle), straw powder, mushroom residue, distillers' grains, herbal residue, humic acid, municipal sludge, and food waste. In the compound and blended fertilizer sectors, it is used to polish and shape NPK compound fertilizer granules, fertilizers containing secondary and trace elements, and soil conditioners. In feed processing, it is commonly used to polish the surfaces of pelleted feed for livestock, poultry, and aquaculture. In the biomass energy sector, it is suitable for the surface treatment of biomass fuel pellets. The equipment integrates seamlessly with virtually all upstream granulation processes—such as flat-die, ring-die, double-roller extrusion, disc granulation, and drum granulation—allowing for inline post-shaping.

Types of usable raw materials

The raw materials processed by the spheronizer are not the original feedstocks but rather semi-finished granules produced during a preliminary granulation stage. These granules are derived from sources such as livestock and poultry manure (chicken, pig, and cattle manure, etc.), crop stalks, organic waste (peat, lignite, organic fertilizer sludge, food waste residues, etc.), oil-cake fertilizers (soybean cake, etc.), and various chemical fertilizer raw materials (compound fertilizers, blended fertilizers, etc.).

Operating Principles and Forming Mechanisms

The operating principle of the spheronizer relies on the combined action of centrifugal force, friction, and gravity. The process begins with irregular granules—produced during the granulation stage—being fed via a conveyor belt into the machine's hopper and distributed evenly onto the center of a high-speed rotating polishing disc. Driven by the transmission system, the disc spins rapidly (typically at 500–1,500 rpm), generating strong centrifugal force that propels the granules toward the inner wall of the processing chamber. As the chamber remains stationary, the material moves in a twisting, rope-like, reciprocating pattern along the edge of the polishing disc and the chamber wall. Under the combined influence of centrifugal force, friction, and gravity, the granules continuously roll, collide, and rub against the wall, gradually smoothing out their sharp edges; simultaneously, aided by a liquid spraying system, their surfaces become smooth and dense, resulting in rounded, spherical particles. Once the continuous feed reaches the height of the shaping disc's discharge outlet, the material automatically transfers to the next spheronization stage. After undergoing the same motion across multiple stages, the cylindrical material is gradually transformed into uniform, glossy, spherical granules. Finally, the shaped granules are sorted via a grading screen: compliant granules proceed to the drying stage, while non-compliant ones are returned to the hopper for re-processing.