Fertilizer production technology - Granulation Part -1- Wet granulation - Rotary Drum Granulator
Date:2024/07/09
Rotary Drum Granulation
Rotary Drum Granulator includes: cylindrical rotating drum, motor, reducer, etc., arranged according to a certain Angle. At the same time as the drum rotates, raw material particles and water or granulation accelerator liquid are fed from the upper end of the drum and granulation is achieved through the rolling of the drum. In the rotating drum, the raw powder particles are discharged from the lower end of the rotating drum, and go through the formation, growth, setting and completion of the particle nucleus. The main difference between drum granulation and disc granulation is that drum granulation has no grading effect on the particle size of granulation particles, all granulation particles enter through the feed port, and the particle size distribution after granulation tends to be nearly normal.
Compared with the Disc Granulator, the granulation cost of the Rotary Drum Granulator is higher, the installation area required is larger, the particle situation is not obvious in the granulation process, it is not classified, there are more waste particles, and it is necessary to return the material to pelletizing, so at present, the introduction of a new granulator often gives priority to the Disc Granulator.
In order to improve production efficiency, drying facilities can be set up at the back end of the Rotary Drum Granulator to dry particles at the same time.
1, the structure of Rotary Drum Granulator
1.1 Roller
The roller is a granulation container. It is a cylindrical shape made of steel plate, and the interior is usually affixed with a rubber plate to prevent the highly viscous material from adhering to the wall of the cylinder. The length and diameter of the roller depend on the quality requirements of the granulated material and the quality requirements of the granulated particles, and the calculation method will be introduced in the following chapters. A rotating drive gear and a rotating stop wheel to maintain a stable position are installed on the outer circumference of the drum.
1.2 Motor and reducer, drive roller
The motor powers the rotation of the drum. The motor output is decelerated by the reduction gear, and the cylinder is driven by the reduction gear to rotate.
1.3 Angle adjustment device
This is a device to adjust the tilt Angle of the drum, which is used to adjust the Angle of the drum tilt placement. Small drum granulators usually use manual adjustment, while large drum granulators use electric regulators.
1.4 Material input port
Typically, a hopper is installed on the feeder, and particles transported from the conveyor belt are stored in the hopper and then fed in the rotary drum of the feeder.
1.5 Particulate Matter Outlet
The pellet outlet is installed at the bottom of the drum and is used to receive the pellet and feed it to the drying equipment or screening machine.
3. Special use of drum granulator
In addition to fertilizer granulators, there are some special purpose drum coating granulators, such as drum phosphate fertilizer (DAP, MAP) granulators, drum coating granulators with ammoniating reaction equipment, etc. These granulators are equipped with hot air drying (Rotary Dryer ; Gas-oil Burner Fire Stove)and screening equipment, and the unqualified small particles are used as the return material and the rotary drum is used as the particle core. The growth of the particles is not rolling adhesion, but mainly the slurry blown by compressed air is coated on the small particles of the powder, which is shaped and dried during the rolling process.
Rotary Drum Granulator includes: cylindrical rotating drum, motor, reducer, etc., arranged according to a certain Angle. At the same time as the drum rotates, raw material particles and water or granulation accelerator liquid are fed from the upper end of the drum and granulation is achieved through the rolling of the drum. In the rotating drum, the raw powder particles are discharged from the lower end of the rotating drum, and go through the formation, growth, setting and completion of the particle nucleus. The main difference between drum granulation and disc granulation is that drum granulation has no grading effect on the particle size of granulation particles, all granulation particles enter through the feed port, and the particle size distribution after granulation tends to be nearly normal.
Compared with the Disc Granulator, the granulation cost of the Rotary Drum Granulator is higher, the installation area required is larger, the particle situation is not obvious in the granulation process, it is not classified, there are more waste particles, and it is necessary to return the material to pelletizing, so at present, the introduction of a new granulator often gives priority to the Disc Granulator.
In order to improve production efficiency, drying facilities can be set up at the back end of the Rotary Drum Granulator to dry particles at the same time.
1, the structure of Rotary Drum Granulator
1.1 Roller
The roller is a granulation container. It is a cylindrical shape made of steel plate, and the interior is usually affixed with a rubber plate to prevent the highly viscous material from adhering to the wall of the cylinder. The length and diameter of the roller depend on the quality requirements of the granulated material and the quality requirements of the granulated particles, and the calculation method will be introduced in the following chapters. A rotating drive gear and a rotating stop wheel to maintain a stable position are installed on the outer circumference of the drum.
1.2 Motor and reducer, drive roller
The motor powers the rotation of the drum. The motor output is decelerated by the reduction gear, and the cylinder is driven by the reduction gear to rotate.
1.3 Angle adjustment device
This is a device to adjust the tilt Angle of the drum, which is used to adjust the Angle of the drum tilt placement. Small drum granulators usually use manual adjustment, while large drum granulators use electric regulators.
1.4 Material input port
Typically, a hopper is installed on the feeder, and particles transported from the conveyor belt are stored in the hopper and then fed in the rotary drum of the feeder.
1.5 Particulate Matter Outlet
The pellet outlet is installed at the bottom of the drum and is used to receive the pellet and feed it to the drying equipment or screening machine.
3. Special use of drum granulator
In addition to fertilizer granulators, there are some special purpose drum coating granulators, such as drum phosphate fertilizer (DAP, MAP) granulators, drum coating granulators with ammoniating reaction equipment, etc. These granulators are equipped with hot air drying (Rotary Dryer ; Gas-oil Burner Fire Stove)and screening equipment, and the unqualified small particles are used as the return material and the rotary drum is used as the particle core. The growth of the particles is not rolling adhesion, but mainly the slurry blown by compressed air is coated on the small particles of the powder, which is shaped and dried during the rolling process.