The hydraulic roller granulator is a granulation machine that utilizes a hydraulic system to apply pressure, forcing material between two counter-rotating rollers to form granules. By incorporating hydraulic pressurization and control technologies into the design of traditional double-roller granulators, this model significantly enhances granulation efficiency and product quality, making it widely applicable in fields such as fertilizer production, chemical raw material processing, and mineral processing.
As an upgraded version of the standard double-roller granulator, the hydraulic model overcomes issues associated with traditional mechanical spring-based pressurization——such as unstable pressure and cumbersome adjustment——establishing itself as a core piece of granulation equipment in modern production lines.
The working principle of the hydraulic roller granulator is based on material extrusion technology. Two rollers rotate towards each other under immense pressure generated by hydraulic cylinders; material falls evenly from the top inlet into the gap between the rollers and is squeezed into granules of a predetermined shape, constrained by the grooves (or sockets) on the roller surfaces.
The core operational process is as follows:
1. Feeding stage: Material is evenly delivered by the feeding device into the extrusion zone between the two rollers.
2. Extrusion and forming: The hydraulic system drives the rollers to generate an extrusion pressure of 30–50 MPa, compressing the material within the mold cavities into spherical or pillow-shaped granules.
3. Demolding and discharge: The formed granules exit the mold cavities as the rollers rotate and are subsequently screened to yield the final product.
4. Pressure regulation: The hydraulic station monitors system pressure in real-time and automatically compensates to maintain constant pressure, ensuring uniform granule density.
The incorporation of a hydraulic system allows for automatic adjustment of the roller gap; the rollers can retract to avoid damage when encountering excessively hard foreign objects, thereby effectively protecting the equipment's core components—a key advantage over traditional mechanical spring-loaded systems.
Thanks to their broad material adaptability and stable forming capabilities, hydraulic roller granulators are widely used in the following sectors:
Fertilizer industry: Cold-press granulation of compound fertilizers, organic-inorganic compound fertilizers, and controlled-release fertilizers; particularly suitable for fertilizer formulations unsuitable for heat-based granulation.
Chemical industry: Granule formation for inorganic salts such as calcium chloride, potassium nitrate, and potassium sulfate.
Mineral processing: Granulation of powdered materials such as graphite, coke breeze, and coal dust.
Environmental protection industry: Resource recovery and utilization of materials like fly ash and desulfurization gypsum in solid waste treatment.
Construction materials industry: Pre-granulation of powders such as ceramic raw materials and refractory materials.
Different materials have varying requirements regarding granulation pressure, roll surface materials, and feed moisture content; it is recommended to provide material samples for testing when selecting equipment.
Hydraulic roller granulators rarely operate as standalone units; complete production lines range from simple, short-process setups to fully automated assembly lines.
Simple Production Line (Budget-friendly option for small to medium-sized plants)
Raw material crusher —— Horizontal mixer —— Hydraulic roller granulator ——Drum screener——Packaging machine
Oversized or undersized material (fines) separated during screening is returned to the mixer for recycling, either manually or via a simple belt conveyor.
Automated Production Line (Standard configuration for large-scale plants)
Raw material crusher—— Mixer —— Screw conveyor ——Hydraulic roller granulator (main unit) —— Bucket elevator—— Cooler ——Drum screener —— Finished product belt conveyor ——Automatic packaging machine
A return conveyor system handles the fines separated during screening, enabling a fully automated, continuous recycling loop; a pulse-jet bag dust collector can be installed for operations generating significant dust.
Many buyers confuse these two types of equipment; while they share similar external structures, there are significant differences in their pressurization methods, stability, and suitability for various operating conditions. A comparison follows below:
Standard double roller granulators rely on large springs to generate pressure; prolonged continuous production leads to spring fatigue and deformation, causing a steady drop in extrusion force, which results in loose granules and increased powder generation over time.
Hydraulic roller granulators utilize a hydraulic station for stable pressure output, maintaining constant pressure over extended periods and ensuring consistent granule quality during continuous, large-scale production.
With double roller granulators, the presence of stones or metal impurities can easily cause roller shell cracking and main shaft bending, resulting in high repair costs;
In contrast, hydraulic roller granulators feature automatic pressure-relief protection—automatically releasing hydraulic pressure when foreign objects enter the roll gap—thereby significantly reducing the likelihood of major breakdowns.
Standard roller granulators have a lower initial purchase price; while hydraulic roller granulators entail higher upfront costs, they offer superior long-term operational stability and reduced wear on consumable parts, resulting in a more advantageous overall operating cost under continuous production conditions.
Selection Recommendations:Standard double roller granulators are suitable for intermittent production, limited budgets, and applications involving raw materials with stable properties. Hydraulic roller granulators are the preferred choice for large-scale continuous production, applications with significant raw material variability, and scenarios requiring high consistency in granule strength.
| Model | DGZ-1 | DGZ-2 | DGZ-3 | |
| Capacity | 1-1.5t/h | 2-3t/h | 3-4.5t/h | |
| Granulator rate | ≧85% |
≧85% |
≧85% |
|
| Power | 15kW | 30kW | 37kW | |
| Material moisture | 2%-5% |
|||
| Granulation temperature | Normal temperature | |||
| Particle | Diameter | 4-10（mm） | ||
| Strength | 6-20N(Compression crushing) |
|||
| Shape | Oblate sphere | |||
