If you’ve ever wondered what a fluidizer is used for, you aren’t alone. This article will give you an understanding of the process and characteristics of a fluidized bed dryer. You’ll also discover the various chemical reactions that take place in this type of drying chamber. Keep reading for more information!
Fluidized Bed Drying
Fluidized bed drying is a process used to dry products. It is used to produce granulated or agglomerated products. In this process, a liquid is sprayed on a fluidized bed of particles. The particles collide with the liquid, creating agglomerates that are dried to stable moisture content. Fluidized bed agglomerators are available as continuous systems or as standalone units.
The process is commonly used in the pharmaceutical and chemical industries to dry granular solids and moist powders. It offers high mass and heat transfer rates and minimizes contact time. However, it has several disadvantages. The first is that it can be expensive. The second is that it requires a significant amount of gas handling. Another disadvantage of fluidized bed drying is that it is inefficient to remove organic solvents. The process can also lead to the aggregation of fine particles.
Process of Fluidizing Granules
The process of fluidizing granules is a key step in the production of a variety of products. Granules can be fluidized at different temperatures for different applications. One of the most important attributes of granules is their particle size distribution. This information can be used to adjust process variables during the subsequent drying phase. It can also be used to determine the tapped density of the final product.
The granule-size data were recorded continuously in line. The data were analyzed to better understand the granule growth mechanism. The in-line-measured GSD correlated with off-line-measured tapped density using univariate and multivariate models. In this way, the researchers could estimate tapped density early in the process.
Characteristics of a Fluidized Bed Dryer
A fluidized bed dryer uses a heat transfer to heat a solid bed. The heat transfer rate of a fluidized bed dryer depends on the solid particle size. Small particles absorb heat more readily than large ones. The height of a fluidized bed also affects heat transfer. A high particle height increases the heat transfer coefficient, while a low particle height decreases the coefficient. Particle size also affects heat transfer; the smaller a particle is, the greater its distance from the heat source.
A fluidized bed is a mixture of solids and liquids that exhibits fluid-like properties. The fluidized bed surface is generally horizontal, similar to hydrostatic behavior. A fluidized bed can be either homogeneous or heterogeneous, representing one bulk density.
Chemical Reactions that Occur in a Fluidized Bed
Fluidized beds are used to study chemical reactions. The chemical reactions in these beds occur at varying velocities. The intensity of circulating flows depends on several factors, such as the size and shape of the fluidized bed. The presence of large bubbles can disrupt the chemical reaction. Therefore, a fluidized bed with a “slow” bubble configuration is more useful for chemical processes.
Fluidized beds can be homogeneous or heterogeneous. The first one involves uniformly dispersed solid particles, and the other involves gas bubbles that do not contain solids. The second type is bubbling fluidization which occurs at higher velocities than homogeneous fluidization. It involves forming different gas bubbles, which grow from the distributor and coalesce at the surface of the fluid bed.
Cost of a Fluidized Bed Dryer
Fluid bed dryers offer the best solution for drying a variety of products. They are particularly helpful in pharmaceutical products as they can control the air temperature to ensure the right amount of moisture evaporates. However, a fluid bed dryer should be controlled carefully since too high a temperature can cause the surface to form a crust, which inhibits the transport of deeper moisture to the surface and slows the drying process. There are several important factors to consider before purchasing a fluidized bed dryer, including the following:
Different manufacturers produce different types of fluidized bed dryers, which allows you to choose the one that fits your requirements. You can also choose various sizes, allowing you to choose a product that meets your budget without compromising on performance. Different models are designed for different types of materials. Some are mobile, so you can easily transport them from one location to another.
Maintenance of a Fluidized Bed Dryer
Fluidized bed dryers have two main components: the bowl containing the product and the filter bags. Both parts are connected to the blower and are equipped with actuators. These actuators can control the airflow and temperature of the dryer. In addition, fluidized bed dryers are equipped with a secondary filter that deals with fine dust, which may be sized as small as one micron. Cleaning the filter bags is a must if the dryer is to provide the best results.
The first step in fluidized bed dryer maintenance is a thorough inspection. Check for leaky joints, and ensure the machine is operating at its peak efficiency. Also, check for clogged and blocked filters, and clean the dryer regularly. The second step involves routine checks of the compressor and air preparation unit.