Fertilizer production technology - Granulation part -1- Wet granulation - drum granulation principle
Date:2024/07/03
Principle of drum granulation (rotary drum granulator):
Drum granulation method is the method of raw material particles with water or granulation accelerator in a granulation container such as a disc (disc granulator) or a drum ( rotary screener) to granulate raw material particles into the required size, which is a wet granulation method. The production process is to continuously feed the raw material powder into the granulation container, such as a slow rotating disk or drum, spray an aqueous solution or granulation accelerator in the container, the particles roll along the rotating direction of the granulation container, collide with another particle, combine and grow larger, and finally grow into the desired size of particles.
Demystifying Drum granulation: How does liquid crosslinking force shape perfect particles
Liquid cross-linking force plays a very important role in drum granulation. In the granulation process, when the amount of liquid added is very small, the surface of the particles is not completely wet, the air is in a continuous phase between the particles, the liquid presents a dispersed phase, and a small part of the particles form liquid cross-linking, but the particles are not connected to each other. In this state, the gas-liquid interfacial tension binding force of gas-liquid cross-linking between raw material particles is very weak, and the particles repeatedly combine and disintegrate, making it difficult to form large particles. When the amount of liquid is appropriate, the surface of the particles is completely wet, a large part of the air between the raw material particles is replaced by the liquid, the air becomes a dispersed phase, the liquid becomes a continuous phase, the liquid cross-linked around the air is formed, and they are connected into a network, the liquid cross-linked around the air is formed. At this time, the interfacial tension of liquid crosslinking and capillary negative pressure strongly bind the primary particles together. When the amount of liquid is too large, the space between the particles is completely filled by the liquid, all the air is driven away, the liquid cross-linking between the particles disappears, the gas-liquid interfacial tension disappears, only the surface tension of the liquid is left, the adhesion between the particles dissolves, and the whole becomes a slurry. Therefore, the amount of liquid added is a very important factor in drum granulation, that is, too much or too little liquid added will hinder the granulation process.
Drum granulation method is the method of raw material particles with water or granulation accelerator in a granulation container such as a disc (disc granulator) or a drum ( rotary screener) to granulate raw material particles into the required size, which is a wet granulation method. The production process is to continuously feed the raw material powder into the granulation container, such as a slow rotating disk or drum, spray an aqueous solution or granulation accelerator in the container, the particles roll along the rotating direction of the granulation container, collide with another particle, combine and grow larger, and finally grow into the desired size of particles.
Demystifying Drum granulation: How does liquid crosslinking force shape perfect particles
Liquid cross-linking force plays a very important role in drum granulation. In the granulation process, when the amount of liquid added is very small, the surface of the particles is not completely wet, the air is in a continuous phase between the particles, the liquid presents a dispersed phase, and a small part of the particles form liquid cross-linking, but the particles are not connected to each other. In this state, the gas-liquid interfacial tension binding force of gas-liquid cross-linking between raw material particles is very weak, and the particles repeatedly combine and disintegrate, making it difficult to form large particles. When the amount of liquid is appropriate, the surface of the particles is completely wet, a large part of the air between the raw material particles is replaced by the liquid, the air becomes a dispersed phase, the liquid becomes a continuous phase, the liquid cross-linked around the air is formed, and they are connected into a network, the liquid cross-linked around the air is formed. At this time, the interfacial tension of liquid crosslinking and capillary negative pressure strongly bind the primary particles together. When the amount of liquid is too large, the space between the particles is completely filled by the liquid, all the air is driven away, the liquid cross-linking between the particles disappears, the gas-liquid interfacial tension disappears, only the surface tension of the liquid is left, the adhesion between the particles dissolves, and the whole becomes a slurry. Therefore, the amount of liquid added is a very important factor in drum granulation, that is, too much or too little liquid added will hinder the granulation process.