Nowadays, spray dryers are not limited to drying operations. Sometimes, crushing, classification, and even heating reactions are integrated into one machine, which greatly shortens the production process and diversifies equipment functions.
Different types of spray dryers can be used for different materials or different drying stages of materials. Combined drying can maximize the drying process and make the drying system more reasonable.
Choosing the right drying equipment for customers with drying requirements is a difficult and complex issue. They need to consider all factors such as material characteristics, heating method, drying medium, etc. Due to the different materials and drying requirements, it is impossible to have universal drying equipment to meet all requirements, and only a more suitable drying method and drying form can be selected.
1. Drying temperature: refers to the temperature of the air entering the drying barrel. Due to its physical properties, such as molecular structure, specific gravity, specific heat, moisture content, and other factors, the temperature has certain restrictions during drying. The local additives in the raw materials are volatilized or agglomerated. Too low will cause some crystalline raw materials to not reach the required drying conditions, such as PC / 120 ℃, ABS / 80 to 95 ℃. In addition, in the selection of dry barrels, insulation is required to avoid loss of drying temperature, resulting in a lack of drying temperature or waste of energy.
2. Dew point: In the dryer, first remove the humid air to make it contain low residual moisture. Then reduce its relative humidity by heating the air. At this time, the vapor pressure of the dry air is low. By heating, the water molecules inside the particles get rid of the bond force and diffuse to the air around the particles.
3. Time: In the air around the particles, it takes a certain time for the absorption of heat and the diffusion of water molecules to the surface of the particles. Therefore, resin suppliers should specify the time it takes for a material to dry effectively at the proper temperature and dew point.
4. Airflow: The dry hot air transfers heat to the particles in the drying silo, removes the moisture on the surface of the particles, and then sends the moisture back to the dryer. Therefore, there must be sufficient airflow to heat the resin to drying temperature and maintain this temperature for a certain period of time.
5.Air volume: the only medium that takes away the moisture in the raw material. The air volume will affect the dehumidification effect. Too much air volume will cause the return air temperature to be too high, which will cause overheating and affect its stability. Too small air volume will not completely remove the moisture in the raw materials. The air volume also represents the dehumidification capacity of the dehumidifier dryer.