In the production process of bio organic fertilizer, not only the moisture content of particles after forming generally exceeds the index, but also needs to be dried at low temperature. The water content of organic material is about 30% - 40% after fermentation. In addition to a few fertilizer production processes (roller press granulator) granulation, the moisture content of organic fertilizer granules after granulation is generally between 15% and 20%, and the fertilizer quality index requires that the moisture content is lower than 14%, which needs to be dried.
Therefore, drying is an indispensable and important process in organic fertilizer production line, which directly affects the output, quality and energy consumption. It is very important to select the type and specification of dryer reasonably and control the process conditions.
In order to avoid the death of effective live bacteria due to high temperature in the drying process, the drying temperature of materials should not be higher than 60 ℃ (generally 50 ℃). Therefore, the temperature of hot air in contact with materials should be different according to the moisture content of materials, generally no more than 130 ℃. It is suggested that the hot air temperature can be controlled in sections, which can improve the thermal efficiency and avoid the death of effective live bacteria.
According to these characteristics, it is more appropriate to choose a rotary drum dryer, which is suitable for low-temperature and low-moisture drying, and the temperature of hot air can be controlled in sections to ensure that the material temperature is not higher than the specified temperature during the entire drying process. A natural air cooling section can be added to the rear of the machine, so that the material can be cooled immediately after drying, which has the function of one machine with multiple uses.
The organic fertilizer machine - drum dryer is very suitable for the drying of granular biological fertilizers, and the materials are dried smoothly and uniformly. The particles are not damaged in any way. The residence time and feeding speed can be adjusted to achieve the drying effect. Since most of the hot air can be recycled, the thermal efficiency is high. , The heat source can be steam provided by a biogas boiler.
