Introduction to Disc Pelletizer

I. Overview of Disc Pelletizer

The disc pelletizer is one of the commonly used granulation equipment. It features a simple structure, high structural strength, easy maintenance, convenient operation, high granulation rate and uniform particle size. Well-mixed raw materials are fed into the disc body at a constant speed. Under the combined effects of gravity, centrifugal force and friction between materials, the materials perform up-and-down reciprocating motion inside the disc. When the materials reach the specified particle size, they overflow from the disc edge. This equipment serves as the core device for pelletizing powdery materials.

II. Working Principle of Disc Pelletizer

Raw meal is processed into uniformly sized pellet cores, which are then conveyed into the pelletizing disc. After entering the disc, the pellet cores move along a parabolic path under the action of centrifugal force, friction and gravity. During continuous rolling, the internal moisture of the pellets is squeezed out to the surface. Leveraging the adhesiveness and plasticity of materials, the pellet cores bond with raw meal particles during movement and grow gradually. The adhesiveness of materials and natural volatilization of the surface liquid film endow the pellets with certain mechanical strength.

When the parameters including the inclination angle, rim height and rotating speed of the pelletizing disc as well as material moisture are fixed, pellets of different particle sizes leave the disc edge at different separation angles due to varying gravity, and are finally discharged from the side of the inclined rotating disc body.

III. Structural Characteristics of Disc Pelletizer

The main motor drives the pulley and belt, which transmit power to the pinion through a reducer. The pinion meshes with the large gear fixed at the bottom of the disc. With a specially optimized design, the large gear is mounted on the main shaft fixed on the frame to support the entire pelletizing disc during operation. After materials enter the disc body, continuous rotation of the disc and water spraying enable the materials to bond uniformly and form spherical particles.

Scraper assemblies for the disc bottom and disc wall are installed at the upper and middle parts of the disc body to prevent material adhesion on the disc surface, which greatly extends the service life of the equipment. Continuous material feeding and stable motor operation realize batch and continuous production.

For pelletizing discs with a diameter of 1.2m or smaller, the disc body is directly driven by a geared motor, featuring an ultra-simple structure and easy maintenance.

Disc bottom scrapers are divided into powered and non-powered types, which can be selected according to actual process requirements.

A dust hood can be installed above the disc body based on process or environmental protection needs to avoid dust pollution during operation.

For large-scale pelletizing discs with a diameter of 5m or larger, wear-resistant liners such as high-molecular polyethylene liners can be equipped inside the disc body to effectively prevent disc wear.