Fertilizer production technology - Granulation - Dry granulation - roll extrusion granulation 3 Factors affecting the quality of roller extrusion granulation
Date:2024/07/13
The main factors that affect the granulation quality of roller extrusion granulator are many, including raw material characteristics, equipment parameters, operating conditions and environmental factors. These factors are directly related to the performance, appearance, uniformity and production efficiency of the final pellet product. In actual production, it is necessary to consider these factors according to the specific situation, and take corresponding measures to ensure the stability and consistency of granulation quality. (Note: The dry granulation equipment in the organic fertilizer production line includes: Roller Press Granulator, Flat Die Pelleting Machine, Organic Fertilizer Double die pelleting machine.)
1.Raw material characteristics
Particle size and distribution of raw materials: the size and distribution of raw materials directly affect the difficulty of granulation. The uniform particle size of the raw material is easier to form a stable extrusion layer between the rollers, resulting in uniform particles.
Humidity and viscosity of raw materials: The humidity and viscosity of raw materials are key factors affecting the effect of granulation. Appropriate humidity is conducive to adhesion and molding between particles, but too high humidity will lead to material sticking roller, affecting the normal operation of the granulator and the separation of particles. At the same time, the viscosity of the raw material also affects the strength and shape of the particles.
Chemical composition of raw materials: Different chemical compositions of raw materials in the extrusion process show different physical properties, such as melting point, softening point, etc., which will affect the effect of granulation.
2.Device parameters
Roller gap: The roller gap refers to the minimum distance between two rollers, which determines the amount of pressure the material is subjected to between the rollers. Too small clearance will lead to material difficult to pass through, increase equipment wear; If the gap is too large, effective extrusion can not be formed, affecting the formation of particles.
Roller speed: The roller speed directly affects the extrusion speed and residence time of the material. Too fast speed may lead to the material is not sufficiently extruded, affecting the density and strength of the particles; Too slow a speed will reduce production efficiency.
Roller material and surface treatment: The material and surface treatment of the roller also have a significant impact on the quality of the granulation. High hardness and wear-resistant roller materials can extend the service life of the equipment, and special treatment of the roller surface (such as grooving, sandblasting, etc.) can enhance the friction between the material and the roll surface and promote the formation of particles.
3.Operating conditions
Feed speed: The feed speed should match the rotation speed and clearance of the roller to ensure that the material is sufficiently squeezed between the rollers. Feeding too fast will lead to material accumulation, affecting the effect of granulation; Too slow feed will reduce production efficiency.
Temperature control: For some raw materials that need to be heated and softened, temperature control is crucial. The appropriate temperature can improve the viscosity and fluidity of the material, which is conducive to the molding of the particles. However, too high a temperature may cause the material to burn or deteriorate.
Lubrication and cooling: During continuous production, parts such as rolls and bearings may be heated by friction. Proper lubrication and cooling can reduce wear and failure rates of components while maintaining stable operation of the equipment.
4.Environmental factors
Air humidity: Air humidity has a certain impact on the humidity and viscosity of the material. The high humidity environment may increase the moisture absorption of the material, resulting in difficult granulation.
Dust control: The dust generated during the granulation process not only affects the working environment and the health of personnel, but also may adhere to the material and affect the quality of granulation. Therefore, effective dust control measures are necessary.
1.Raw material characteristics
Particle size and distribution of raw materials: the size and distribution of raw materials directly affect the difficulty of granulation. The uniform particle size of the raw material is easier to form a stable extrusion layer between the rollers, resulting in uniform particles.
Humidity and viscosity of raw materials: The humidity and viscosity of raw materials are key factors affecting the effect of granulation. Appropriate humidity is conducive to adhesion and molding between particles, but too high humidity will lead to material sticking roller, affecting the normal operation of the granulator and the separation of particles. At the same time, the viscosity of the raw material also affects the strength and shape of the particles.
Chemical composition of raw materials: Different chemical compositions of raw materials in the extrusion process show different physical properties, such as melting point, softening point, etc., which will affect the effect of granulation.
2.Device parameters
Roller gap: The roller gap refers to the minimum distance between two rollers, which determines the amount of pressure the material is subjected to between the rollers. Too small clearance will lead to material difficult to pass through, increase equipment wear; If the gap is too large, effective extrusion can not be formed, affecting the formation of particles.
Roller speed: The roller speed directly affects the extrusion speed and residence time of the material. Too fast speed may lead to the material is not sufficiently extruded, affecting the density and strength of the particles; Too slow a speed will reduce production efficiency.
Roller material and surface treatment: The material and surface treatment of the roller also have a significant impact on the quality of the granulation. High hardness and wear-resistant roller materials can extend the service life of the equipment, and special treatment of the roller surface (such as grooving, sandblasting, etc.) can enhance the friction between the material and the roll surface and promote the formation of particles.
3.Operating conditions
Feed speed: The feed speed should match the rotation speed and clearance of the roller to ensure that the material is sufficiently squeezed between the rollers. Feeding too fast will lead to material accumulation, affecting the effect of granulation; Too slow feed will reduce production efficiency.
Temperature control: For some raw materials that need to be heated and softened, temperature control is crucial. The appropriate temperature can improve the viscosity and fluidity of the material, which is conducive to the molding of the particles. However, too high a temperature may cause the material to burn or deteriorate.
Lubrication and cooling: During continuous production, parts such as rolls and bearings may be heated by friction. Proper lubrication and cooling can reduce wear and failure rates of components while maintaining stable operation of the equipment.
4.Environmental factors
Air humidity: Air humidity has a certain impact on the humidity and viscosity of the material. The high humidity environment may increase the moisture absorption of the material, resulting in difficult granulation.
Dust control: The dust generated during the granulation process not only affects the working environment and the health of personnel, but also may adhere to the material and affect the quality of granulation. Therefore, effective dust control measures are necessary.