Description

I. Brief Introduction

The Drum Granulator is essential equipment in the field of compound fertilizers. This rotary drum granulator is designed for cold granulation, heat granulation, and guniting granulation. It is suitable for large-scale production of fertilizers with high, medium, and low concentrations. The manufacturing process is easy to control and adaptable to a variety of raw materials.

II. Structure Principle

The cylinder of the rotary drum granulator is constructed from rolled and welded steel plates. Steel rolling rings are installed at both ends of the cylinder, supported by rollers. A larger gear ring is situated in the middle of the cylinder, and a motor drives both the gear ring and the cylinder’s rotation through a transmission device and pinion.

At the feeding end of the cylinder, we have set a blocking ring to prevent material overflow. Another blocking ring is positioned in the middle of the cylinder, dividing it into two sections: the granulating area in the front and the granulation area in the back. The function of the blocking ring is to control the volume of material in the front section, thus managing the retention time, which allows us to regulate particle size and the extent of ammoniation.

The cylinder is installed at a slope towards the discharge end. As powder materials and returned materials are fed in from the material-feeding end, the rotating cylinder elevates the materials. Gravity then causes the materials to exit the cylinder after reaching a certain height. The materials fall along an arc path due to gravity and inertial force, completing the rolling action necessary for granulation while simultaneously moving towards the discharge end.

We recommend installing a steam and water pipeline within the cylinder, composed of one main pipe and four branch pipes. Each branch pipe features a 2-3mm gap at the end, allowing steam to be sprayed at a 60°C angle towards the material bed. The direction of steam exit aligns with the cylinder’s rotation, maintaining a distance of about 80-150mm from the cylinder wall to ensure proper granule formation. The granulation ratio exceeds 50%.

During the granulation process, materials may adhere to the cylinder’s surface, forming scales. To address this, we line the interior with rubber plates that are resistant to acids and alkalis. We utilize steam or hot water to directly heat the base materials for granulation, enhancing the granulation strength and allowing for precise control over temperature and humidity. This prevents deformation and adhesion of granules during drying, facilitating efficient process control suitable for large-scale production.