The advantages and disadvantages of the drying equipment and the constraints on the play of the factors to be fully understood

The advantages and disadvantages of the drying equipment and the constraints on the play of the factors to be fully understood

Abstracts:

Drying equipment is heated to make the material in the moisture (generally refers to water or other volatile liquid components) vapor escape, to obtain the specified amount of moisture in the solid material. The purpose of drying is for material use or further processing. In practice, drying is a relatively simple process, however, in some cases, particles are not completely dry. The reason for this is due to a number of external factors that influence…

Drying equipment is heated to make the material in the moisture (generally refers to water or other volatile liquid components) vapor escape, to obtain the specified amount of moisture in the solid material. The purpose of drying is for material use or further processing. In practice, drying is a relatively simple process, but, in some cases, particles do not dry completely. The reason for this is because some external factors affect the effect of drying, specifically the following aspects:

1. Drying temperature: refers to the air temperature into the drying barrel, each raw material due to its physical properties, such as molecular structure, specific gravity, specific heat, moisture content and other factors, drying temperature are certain restrictions, the temperature is too high when the raw materials in the local additive volatilization and deterioration or agglomeration, too low will make some crystalline raw materials can not achieve the required drying conditions. In addition, in the dry barrel selection needs to be insulated to avoid drying temperature leakage, resulting in a lack of drying temperature or waste of energy.
2. Dew point: in the dryer, first remove the wet air, so that it contains a very low residual moisture (dew point). Then, the relative humidity is reduced by heating the air. At this point, the vapor pressure of the dry air is low. By heating, the water molecules inside the particles are freed from bonding forces and diffuse into the air around the particles.
3. Time: In the air around the pellet, it takes some time for the heat to be absorbed and the water molecules to diffuse to the surface of the pellet. Therefore, the resin supplier should detail the time required for the material to dry effectively at the proper temperature and dew point.
4. Airflow: Dry hot air transfers heat to the particles in the drying bin, removes moisture from the particle surface, and then sends the moisture back into the dryer. Therefore, there must be enough airflow to heat the resin to the drying temperature and maintain that temperature for a certain period of time.
5. air volume: air volume to take away the moisture in the raw material of the only Y medium, the size of the air volume will affect the dehumidification effect is good or bad. Air flow is too large to lead to the return air temperature is too high, resulting in overheating phenomenon and affect its stability, the wind flow is too small can not take away the moisture in the raw materials completely, the wind flow also represents the dehumidification dryer dehumidification capacity.

Advantages:

1. The drying time of the material is very short (in seconds) because of the large surface area of the droplet group.

2. In the high temperature airflow, the temperature of the surface-wetted material does not exceed the wet bulb temperature of the drying medium, and the temperature of the final product is not high due to rapid drying. Therefore, spray drying is suitable for heat-sensitive materials.
3. High production efficiency and few operators. Large production capacity and high product quality. Hourly spray volume can reach hundreds of tons, is one of the dryer handling capacity.
4. According to the flexibility on spray drying operation, it can meet the quality indexes of various products, such as particle size distribution, product shape, product properties (dust-free, fluidity, wettability, quick-solubility), product color, aroma, taste, biological activity and wet content of the final product.
5. Simplify the process. The solution can be made into powder products directly in the drying tower. In addition, spray drying is easy to mechanize, automate, reduce dust flying, improve the labor environment.