Spray Dryer
Methods of Spray Drying and Comparison of Merit and Demerit
Time：2018.03.16
There are many types of drying granulators, but spray drying granulator is the most widely used.
The spray dryer was designed based on the introduction of foreign products of the same type in the 1980s, and was designed after digestion, absorption and improvement. As the spray dryer is easy to operate, superior in performance, and excellent in manufacturing, it can meet the GMP requirements of the pharmaceutical and food industries, and is welcomed by users in the pharmaceutical and food industries. The device is especially suitable for drying and granulating Chinese and Western medicines and foods. The obtained particles have strong disintegration degree, good fluidity and fast dissolving property, and can be directly used for tableting, filling capsules, granules and solid beverages, etc.
Spray drying has the special advantages of powdered products which can be directly obtained from the solution or suspension system, and is currently widely used in the chemical, light industry, food and other industries. The chemical industry is most commonly used in the dye industry. Through the efforts of engineers and technicians in recent years, spray drying technology has become more mature, and the determination of tower size has also been successfully calculated.
Spray drying refers to that the liquid to be dried is atomized into tiny droplets in a drying chamber through a nebulizer, and the hot gas in the drying medium is directly contacted and mixed to evaporate water, and then by the method of gas-solid separation collection to obtain powder or granular products.
The raw material liquid can be solution, emulsion, or suspension, or can be melt or paste. The drying medium can be air, nitrogen or superheated steam.
The main components of the spray drying system are: air heating system, raw material liquid delivery system, atomizer, drying system, gas-solid separation and collection system, control system, special requirements of the media circulation mechanism and other components.
Spray drying is a method of systematic application of material drying. After the thin material is atomized in the drying chamber, the moisture rapidly vaporizes in contact with the hot air to obtain a dried product. The method can directly dry the solution and the emulsion into a powdery or granular product, and evaporation and crushing and other processes can be omitted. Through mechanical action, the materials to be dried are dispersed into very fine mist-like particles (by increasing the evaporation area of the water and accelerating the drying process) in contact with the hot air, most of the water is removed in an instant and the solids in the material are removed and the solid material is dried into powder.
Spray drying has the characteristics of rapid heat transfer, rapid evaporation of water and short drying time, good product quality, crisp texture, good dissolution performance, and can improve the dissolution rate of certain preparations. It is suitable for heat-sensitive drugs. In addition, spray drying is also can be used to make microcapsules.
Spray drying is a widely used method for dye drying. A drying method that atomizes the dye to remove moisture. Suitable for drying all kinds of dyes. It can dry dye fine powder, ultrafine powder, no dust powder and hollow granules. According to the dye atomization method, it can be divided into three categories: (1) air-flow atomization, the use of compressed air or water vapor to atomize the feed liquid; (2) pressure-type atomization, high pressure pump is used to press the feed liquid out of the nozzle at high speed to form the fog; (3)Rotary atomization, the material liquid is added to the high-speed spinning disc (7000 ~ 28000r/min) in the atomizer, the material liquid is quickly thrown and atomized. The third method has good effect, short time, high labor productivity, which is favored by the dye industry. The disadvantages of the third method are large equipment investment and high energy consumption.
Advantage
1. The drying process is very rapid.
2. It can be dried directly into powder.
3. Easy to change the drying conditions, adjust product quality standards.
4. Due to instant evaporation, equipment material selection requirements are not strict.
5. There is a certain negative pressure in the drying chamber, which ensures the sanitary conditions in the production and avoids dust flying in the workshop and improves product purity.
6. High production efficiency, fewer operators.
7. Large production capacity and high product quality. The spray quantity can reach several hundred tons per hour, which is one of the larger dryers.
8. The spray dryer is easy to adjust, it can change the operating conditions in a wide range to control the product quality indicators, such as particle size distribution, moisture content, biological activity, solubility, color, aroma, taste and so on. [1]
Disadvantages
1. The equipment is more complex and covers a large area with large investment at a time.
2. Nebulizer, powder recovery device is expensive.
3. Need more air, increase the power consumption of the blower and the capacity of the recovery device.
4. The thermal efficiency is not high and the heat consumption is high.
The spray dryer was designed based on the introduction of foreign products of the same type in the 1980s, and was designed after digestion, absorption and improvement. As the spray dryer is easy to operate, superior in performance, and excellent in manufacturing, it can meet the GMP requirements of the pharmaceutical and food industries, and is welcomed by users in the pharmaceutical and food industries. The device is especially suitable for drying and granulating Chinese and Western medicines and foods. The obtained particles have strong disintegration degree, good fluidity and fast dissolving property, and can be directly used for tableting, filling capsules, granules and solid beverages, etc.
Spray drying has the special advantages of powdered products which can be directly obtained from the solution or suspension system, and is currently widely used in the chemical, light industry, food and other industries. The chemical industry is most commonly used in the dye industry. Through the efforts of engineers and technicians in recent years, spray drying technology has become more mature, and the determination of tower size has also been successfully calculated.
Spray drying refers to that the liquid to be dried is atomized into tiny droplets in a drying chamber through a nebulizer, and the hot gas in the drying medium is directly contacted and mixed to evaporate water, and then by the method of gas-solid separation collection to obtain powder or granular products.
The raw material liquid can be solution, emulsion, or suspension, or can be melt or paste. The drying medium can be air, nitrogen or superheated steam.
The main components of the spray drying system are: air heating system, raw material liquid delivery system, atomizer, drying system, gas-solid separation and collection system, control system, special requirements of the media circulation mechanism and other components.
Spray drying is a method of systematic application of material drying. After the thin material is atomized in the drying chamber, the moisture rapidly vaporizes in contact with the hot air to obtain a dried product. The method can directly dry the solution and the emulsion into a powdery or granular product, and evaporation and crushing and other processes can be omitted. Through mechanical action, the materials to be dried are dispersed into very fine mist-like particles (by increasing the evaporation area of the water and accelerating the drying process) in contact with the hot air, most of the water is removed in an instant and the solids in the material are removed and the solid material is dried into powder.
Spray drying has the characteristics of rapid heat transfer, rapid evaporation of water and short drying time, good product quality, crisp texture, good dissolution performance, and can improve the dissolution rate of certain preparations. It is suitable for heat-sensitive drugs. In addition, spray drying is also can be used to make microcapsules.
Spray drying is a widely used method for dye drying. A drying method that atomizes the dye to remove moisture. Suitable for drying all kinds of dyes. It can dry dye fine powder, ultrafine powder, no dust powder and hollow granules. According to the dye atomization method, it can be divided into three categories: (1) air-flow atomization, the use of compressed air or water vapor to atomize the feed liquid; (2) pressure-type atomization, high pressure pump is used to press the feed liquid out of the nozzle at high speed to form the fog; (3)Rotary atomization, the material liquid is added to the high-speed spinning disc (7000 ~ 28000r/min) in the atomizer, the material liquid is quickly thrown and atomized. The third method has good effect, short time, high labor productivity, which is favored by the dye industry. The disadvantages of the third method are large equipment investment and high energy consumption.
Advantage
1. The drying process is very rapid.
2. It can be dried directly into powder.
3. Easy to change the drying conditions, adjust product quality standards.
4. Due to instant evaporation, equipment material selection requirements are not strict.
5. There is a certain negative pressure in the drying chamber, which ensures the sanitary conditions in the production and avoids dust flying in the workshop and improves product purity.
6. High production efficiency, fewer operators.
7. Large production capacity and high product quality. The spray quantity can reach several hundred tons per hour, which is one of the larger dryers.
8. The spray dryer is easy to adjust, it can change the operating conditions in a wide range to control the product quality indicators, such as particle size distribution, moisture content, biological activity, solubility, color, aroma, taste and so on. [1]
Disadvantages
1. The equipment is more complex and covers a large area with large investment at a time.
2. Nebulizer, powder recovery device is expensive.
3. Need more air, increase the power consumption of the blower and the capacity of the recovery device.
4. The thermal efficiency is not high and the heat consumption is high.