How to dry wet compound fertilizer granules?

Particle drying is an essential step in the production line of nitrogen, phosphorus and potassium fertilizer. The state requires that the moisture content of compound fertilizer must be less than 30% to meet the national standard. Then in the process of compound fertilizer production, the water content of organic fertilizer after granulation reaches about 50%.

Sometimes even higher, the moisture content of dry particles has become an important link in fertilizer production.

Rotary Drum Dryer Used in Fertilizer Production Line
Rotary Drum Dryer Used in Fertilizer Production Line

In the drying process of fertilizer manufacturing process, it is very important to pay attention to the drying method. The fertilizer produced by the compound fertilizer equipment is full dry fertilizer. So how does compound fertilizer equipment produce dry fertilizer? What are the methods?

1. Mechanical dewatering method: mechanical dewatering method is to pressurize materials and then extrude some water. Common methods include pressing, sedimentation, filtration, centrifugation, etc. Mechanical dehydration is only used for the initial dehydration of raw materials. This method is not suitable for the production of particles.

Therefore, the moisture content of materials after mechanical dehydration is still high, generally 40-60%. However, mechanical dehydration is the most economical method, which is most suitable for the dehydration of poultry and animal feces.

2. Heating and drying method of compound fertilizer dryer: This is what we often call drum dryer drying method. It uses heat energy to enter the dryer barrel, and the temperature in the barrel reaches about 150 degrees. According to different materials, the temperature can be adjusted to evaporate the water in the materials.

A certain amount of heat energy is required to remove the water in the materials. This method usually uses air to dry the material. The air is preheated and sent to the dryer to transfer heat to the material, so that the water in the material evaporates to form water vapor, which is brought out of the dryer with the air.

The material can be heated and dried to remove the combined water in the material, so as to achieve the water content required by the product or raw material. This method can be applied to a variety of industries, and it is also one of the simplest methods to meet the requirements.

3. Chemical dehumidification method: this method uses hygroscopic agent to remove a small amount of moisture in gas, liquid and solid materials. Due to the limited dehumidification capacity of hygroscopic agent, it is now only used to remove trace moisture in materials. Therefore, this method is rarely used in production.

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