标签档案:定期监测

  • -

流化床烘干机

标签:

流化床干燥机(又称流化床干燥机)是制药工业中广泛应用的一种用于降低药粉、颗粒水分含量的设备。该设备的工作原理是使原料流化。

在流化工艺中,热空气通过多孔的湿固体颗粒的穿孔床引入高压。湿固体从底部抬起并悬浮在空气流(流化状态)中。通过在湿固体和热气体之间直接接触来实现传热。蒸发的液体通过干燥气体传离。有时可以节省能量,退出气体部分回收。

典型的流化床干燥机包括以下组件

一种。空气磨削单位。

b。产品容器。

c。排气过滤器。

d。排风机。

e。控制面板。

f.配风板。

G。喷嘴。H。解决方案提供。除了确保均匀且稳定的流化过程中,使用期间和干燥过程的选择也可防止1.流化床干燥器中的某些区域中固体的流化质量差。2.插入分配器的孔。3.掉入风箱或位于流化床下方的气孔的固体。分配器中的压降必须足够高,以确保良好和均匀的流化。目录[显示]在流化床干燥器中控制参数(系统),以提高流化床烘干机的运行,效率和再现性,需要控制一些参数。这些参数被分类为:设备参数:由设备控制的那些。 Process parameters: Those controlled by the process. Product parameters: Those controlled by the product. 1. Apparatus/Equipment Parameter Position of the air distribution plate: This parameter influences the pattern. Shape of the instrument: The annular based design gives a better product. Nozzle height: Nozzle height plays a vital role when fluidized bed dryers are used as a coating machine. The atomized coating solution should not get dried before reaching the tablet surface. 2. Process/Operating Parameter Temperature: Increased temperature leads to increased moisture diffusivity and hence increased drying rate and decreased drying time. The nature of the material plays an important role in choosing the operating temperature. Humidity: Faster drying is achieved when the moisture content of the inlet air is maintained at its minimum. Airflow rate/gas velocity: Increasing gas velocity increases drying rate but should be maintained at an optimized rate (not to fast or too slow). Gas velocity has no effect on particles with high internal resistance to moisture transfer. 3. Product Parameters Moisture content of the feed material. Feed rate/batch size. Product moisture content. Particle size, shape, and diameter. Read Also: Rotary Dryer Types of Fluidized-Bed Dryers There are various types of fluidized bed dryer and an individual’s familiarity with the specific characteristics of these various types enables one to make a logical and cost-effective selection of fluidized bed dryer for a drying operation. In many instances, several different types may provide similar performance at the same cost. It should be noted also that not all modified fluidized bed dryers are necessarily better than the conventional dryers in terms of product quality, or energy efficiency, or drug performance. picture of conventional fluid bed dryers 1. Conventional Fluidized Bed Dryers Conventional fluidized bed dryers include; Batch fluidized bed dryers. Semi-continuous fluidized bed dryers. Well-mixed, continuous fluidized dryers. Plug flow fluidized bed dryer. 2. Modified Fluidized Bed Dryers Various types of modified fluidized bed dryers have been developed and are applied in many industrial processes to overcome some of the problems encountered while using conventional fluidized bed dryers for a drying process. They include but not limited to; Hybrid fluidized bed dryers Pulsating fluidized bed dryers Fluidized bed dryer with immersed heat exchange. Mechanically assisted fluidized bed dryer. Vibrated fluidized bed dryer. Agitated fluidized bed dryer/swirl fluidizers. Fluidized bed dryers of inert particles. Spouted bed dryer. Recirculating fluidized bed dryer. Jetting fluidized bed dryer. Superheated steam fluidized bed dryer. Fluidized bed freeze dryer. Heat pump fluidized dryers. It should be noted that not all modified fluidized bed dryers are necessarily better than the conventional dryers in terms of product quality, or energy efficiency, or drying performance. Advantages of Fluidized-bed Dryers 1. High rates of moisture removal due to excellent gas-particle constant which results in high heat and mass transfer rates. 2. High thermal efficiency is usually achieved if part of the thermal energy for drying is supplied by the internal heat exchanger 3. Lower capital and maintenance cost 4. Reduced contact time for drying. 5. Ease of control. Disadvantages of Fluidized Dryers 1. High pressure drops results as a result of the need to suspend the entire bed in gas which equally leads to high energy consumption. 2. Requires increased gas handling due to extensive recirculation of exhaust gas for high thermal efficiency operation. 3. Poor fluidization and low flexibility especially if the feed is too wet. 4. Not the best choice of equipment when organic solvents need to be removed during drying. 5. Non-uniform product quality for certain types of fluidized bed dryers. 6. Entertainment of fine particles. 7. High potential for attrition; and in some cases agglomeration of fine particles. 8. The conventional hot air fluidized bed dryers are not a good choice of dryer when handling toxic or flammable solids since there is danger of fire or explosion of flammability limits are exceeded.

参考Arun S. Mujumdar(2015)。工业干燥手册。CRC新闻,泰勒和弗朗西斯集团,纽约。

标签:烘干机,流化床烘干机,fbd烘干机