Spray Dryer
Three Major Improvements to the Technical Performance of Spr
Time：2018.03.21
Spray dryer technology is now widely improved, but some companies still know little about the use of old spray dryers. They know little about the new products that are being improved, so Xiaobian has specially organized this article. , I hope that all companies have some new understanding of spray dryer technology.
1. Improve product properties
The development of science and technology and the improvement of living standards put ever higher demands on the quality of spray dryer products. For example, some require extremely high bulk density (≥1.0 kg/L) or particularly small (≤0.6 kg/L); some powders with rehydration requirements such as foods, traditional Chinese medicines, etc. often require instant solubility. In general, products with different bulk densities can be produced by changing the dispersion of the atomization and appropriately changing the operating conditions and controlling the drying rate, but the extent of change is limited. It is worth mentioning that in terms of improving the properties of the feed liquid, such as foam spray drying. It is the foaming of the feed liquid prior to spray drying. The method was originally proposed to improve thermal efficiency and was later used to improve the product's properties. It has been proved that the milk powder and other products made by foam spray drying have a large particle size, are porous, have many depressions, and have a rough surface, and have good instant solubility. Since the 80s, spray dryer technology has been used in industrial production.
2. The development of multi-target drying process
Combining the spray dryer with other unit processes, there are two main types that have been successfully developed and applied: one is the spray drying-reaction process. One well-known example is the one-step preparation of sodium tripolyphosphate by spray drying-polymerization. The other type is spray granulation-drying. The solution or suspension is spray-coated on the fine material and combined with the drying of the particles. Depending on the particle size requirements, the solution atomizer can be placed inside or above the particle bed. Spray granulation-drying technology has emerged and applied earlier, and has done a lot of basic research. Since there are many products, such as fertilizers, dyes, etc., made into pellets are more favorable for storage, transportation and use, interest in such technologies has been increasing over the years. According to the mastered technology, the design and operation of the device with a bed diameter of less than 1m are easy to solve, but further research is needed on the issue of larger scale amplification.
3. The development of a combination drying device
The ability to dry directly from liquid materials into powders is the biggest advantage of spray drying. However, spray dryer equipment has low thermal efficiency, large volume, low production capacity and high investment. In recent years, Chinese and foreign drying experts have conducted extensive research on multistage combined drying with spray drying as the first stage. After drying the liquid into a solid, it is further dried in the next-stage dryer, which overcomes the disadvantages of the spray dryer.
Obviously, the basic effect of these measures on spray dryers is the same, namely the cooling tower wall. These methods have been widely used in the drying of Chinese herbal extracts and have certain effects.
1. Improve product properties
The development of science and technology and the improvement of living standards put ever higher demands on the quality of spray dryer products. For example, some require extremely high bulk density (≥1.0 kg/L) or particularly small (≤0.6 kg/L); some powders with rehydration requirements such as foods, traditional Chinese medicines, etc. often require instant solubility. In general, products with different bulk densities can be produced by changing the dispersion of the atomization and appropriately changing the operating conditions and controlling the drying rate, but the extent of change is limited. It is worth mentioning that in terms of improving the properties of the feed liquid, such as foam spray drying. It is the foaming of the feed liquid prior to spray drying. The method was originally proposed to improve thermal efficiency and was later used to improve the product's properties. It has been proved that the milk powder and other products made by foam spray drying have a large particle size, are porous, have many depressions, and have a rough surface, and have good instant solubility. Since the 80s, spray dryer technology has been used in industrial production.
2. The development of multi-target drying process
Combining the spray dryer with other unit processes, there are two main types that have been successfully developed and applied: one is the spray drying-reaction process. One well-known example is the one-step preparation of sodium tripolyphosphate by spray drying-polymerization. The other type is spray granulation-drying. The solution or suspension is spray-coated on the fine material and combined with the drying of the particles. Depending on the particle size requirements, the solution atomizer can be placed inside or above the particle bed. Spray granulation-drying technology has emerged and applied earlier, and has done a lot of basic research. Since there are many products, such as fertilizers, dyes, etc., made into pellets are more favorable for storage, transportation and use, interest in such technologies has been increasing over the years. According to the mastered technology, the design and operation of the device with a bed diameter of less than 1m are easy to solve, but further research is needed on the issue of larger scale amplification.
3. The development of a combination drying device
The ability to dry directly from liquid materials into powders is the biggest advantage of spray drying. However, spray dryer equipment has low thermal efficiency, large volume, low production capacity and high investment. In recent years, Chinese and foreign drying experts have conducted extensive research on multistage combined drying with spray drying as the first stage. After drying the liquid into a solid, it is further dried in the next-stage dryer, which overcomes the disadvantages of the spray dryer.
Obviously, the basic effect of these measures on spray dryers is the same, namely the cooling tower wall. These methods have been widely used in the drying of Chinese herbal extracts and have certain effects.