Spray drying technology is a very promising drying technology in China. It can dry materials into uniform powder materials quickly and conveniently. At present, most universities and research institutes use Lab spray dryer. Summarize the working principle of the Lab spray dryer and the new developments in its application, especially in the application, mainly introduce the specific application of the Lab spray dryer in ordinary spray drying, micronization or structural modification and preparation of microcapsules. Provide a theoretical basis for the expansion of the application field of the Lab spray dryer to enhance the application value of the Lab spray dryer.
With the development of modern science and technology, various industries have higher and higher requirements for product raw materials, especially the manufacturing requirements of powder materials. Spray drying technology is currently one of the most commonly used material powder drying methods, which can reduce The thermal effect of the powder product maintains biological activity. There are many types of spray dryers, but most universities and research institutes choose Lab spray dryer. Its advantages are high efficiency, few procedures, labor saving, relatively simple equipment structure, small footprint, convenience, and good product quality.
At present, domestically produced Lab spray dryer are mainly centrifugal spray dryers and two-fluid spray dryers (ie, airflow spray dryers). The characteristics of centrifugal spray drying are fast drying speed, high degree of atomization, relatively large equipment area, difficult to clean, and high cost; the characteristics of two-fluid spray dryer are small size, not easy to block, beautiful appearance, precise control, The outer wall of the glass bottle makes it convenient for the tester to study the drying process, and can adjust the corresponding problems in time, and the selected high-temperature borosilicate glass material can prevent the phenomenon of dry powder sticking to the wall after antistatic treatment. Due to the laboratory’s site limitations, high precision requirements, and low drying capacity, the two-fluid spray dryer is currently the best choice for laboratories, and it is also the most experimental spray drying used by major universities and research institutes across the country. machine. YC-015 Lab spray dryer is currently used in many applications. This article summarizes the working principle and application of Lab spray dryer with YC-015, aiming to improve the utilization rate of Lab spray dryer.
1 Lab spray dryer working principle
The liquid containing solid components is pumped into the two-fluid nozzle by a peristaltic pump, and the solution is sprayed into tiny droplets by compressed air into the drying chamber. The small mist droplets in the hot air have a large specific surface area, and can conduct heat exchange well to make the surface water vapor rapidly sublime to form dry solid particles. The solid particles are separated from the exhaust gas through the cyclone separator and enter the collection bottle. The exhaust gas is directly discharged to the atmosphere or air filter device . Among them, the dual-fluid nozzle has its own through needle, and adjusting the frequency of the through needle can prevent the nozzle from being blocked. The average particle size of the spray particles can be adjusted by controlling the flow of compressed air.
2 Introduction to the application of lab spray dryer equipment
Lab spray dryer have a wide range of applications, involving the food industry, the pharmaceutical industry, the application of ultra-fine nano powders, and the bioremediation of soil oil pollution. At present, the specific uses of Lab spray dryer mainly include general spray drying, micronization or structural modification, and microcapsules.
Ordinary spray drying is mainly used for most pure solutions, colloidal solutions, and emulsions, as long as the final dried product can behave as a uniform solid.
Lab spray dryer have been widely used in research in various fields.
Examples are as follows:
2.1 In order to improve the nutritional value of the blanching liquid for Stropharia sphaerocarpa, Lab spray dryer was used to test it. The final determination of the process conditions is that the feed temperature is 70 ℃, the feed volume is 0.6 L/h, the atomization pressure is 92MPa, and the inlet air temperature is 172 ℃. In this case, the yield of nutrient concentrate is 60.26%. The water content is 3.2%, the antioxidant retention rate is 83.92%, and the dissolution time is 65 s. When preparing honey papaya powder, Lab spray dryer was used to dry the materials. Through experiments, the formula and processing technology were improved, and the process parameters of the Lab spray dryer were finally determined as the compressed air flow rate of 859 L/h, the feed rate of 15 mL/min, and the inlet temperature of 166 ℃.
2.2 When drying the waste yeast mud of beer, in order to better protect the superoxide dismutase SOD activity in the waste beer yeast mud, Lab spray dryer was used for experimental drying. The process parameters are 4 320 m3/h of inlet air, 134 ℃ of inlet air temperature, and 3.75 mL/min of feed rate.
2.3 Study the effect of auxiliary materials on spray drying of rape pollen extract. The process parameters of the Lab spray dryer are air flow rate of 50 m3/h, feed rate of 20 mL/min, and inlet temperature of 150 ℃. The orthogonal result shows that the best auxiliary material ratio is maltodextrin to rape pollen extract solids The total amount is 70%, carboxymethyl cellulose accounts for 1%, and β-cyclodextrin is 1/10 of maltocyclodextrin.
YC-015 lab spray dryer
2.4 When developing royal jelly powder, the spray drying technology and freeze-drying technology were compared. The results show that the fluidity of the product obtained by freeze-drying technology is worse than that of spray-dried products, and its nutritional value is higher than that of spray-dried products. However, from a production perspective, spray-drying is more energy-saving and environmentally friendly, and has high production efficiency, so it has more advantages . The optimal operating conditions during the spray drying process are gas flow rate of 600 L/h, feed flow rate of 20 mL/min, and inlet air temperature of 160 ℃.
2.5 Use the ordinary spray drying method to carry out the experiments on the blanching liquid, Ganoderma lucidum honey powder and seafood condiments. This method has high efficiency in drying materials, short time, good product solubility and fluidity, insignificant changes in physical and chemical properties, and good product quality.
Micronization or structural modification is mainly to change the shape of the material, and two kinds of substances can be granulated, which is beneficial to the solubility and measurability of the product. The main advantage of micronization is that it can obtain uniform and stable particle sizes, increase the bulk density, and increase the utilization of materials.
2.6 Using Lab spray dryer to change the form of native corn starch, enhance its physical and chemical reaction activity, and form amorphous granular corn starch. The optimal process parameters of spray drying are that the inlet temperature is 230 ℃, the preheating temperature is 70 ℃, and the mass concentration of starch milk is 150 g/L.
2.7 The ginkgo extract is micronized with Lab spray dryer, which improves the dissolution rate of the ginkgo extract and enhances its degreasing effect. The optimal process parameters for spray drying are that the solution flow rate of the ginkgo extract is 20 r/min, the inlet temperature is 160 ℃, and the mass concentration is 1.25 g/L.
2.8 Investigate the possible forms of different types of prednisolone systems under different spray drying process conditions. The results show that granulation can be carried out under the condition of higher temperature (150~190 ℃) of the equipment, while at lower temperature (101~140 ℃), the original particles are basically dried without changing their shape.
2.9 Lab spray dryer was used to prepare the fruit and vegetable micropowder tablets, and an appropriate amount of xanthan gum, glucose and other substances were mixed and granulated. The optimal process parameters are that the inlet air pressure is 0.25~0.3 MPa, the inlet temperature is 180~200 ℃, the feed temperature is 60 ℃, the outlet temperature is 90~100 ℃, and the mass fraction of the feed is 30%. Fan Ting et al. prepared the extract of the nasturtium into a micronized powder in order to improve the utilization of the effective ingredients of the honeysuckle species. The inlet temperature is 80 ℃, the feed rate is 9 mL/min, and the atomization air flow rate is 670 L/h. This method can effectively improve the dissolution and dispersibility of the product, and has obvious advantages in improving the bioavailability. Compared with other micronization methods, the operation is simpler, more economical and safer.
The Lab spray dryer can make the materials into microcapsules or microspheres. The process is to evenly disperse the core material in the material slurry, and then use the Lab spray dryer to spray the mixed solution into the drying chamber to contact with hot air. If the capsule core can be dissolved in it, it can be made into microspheres; if it is insoluble, it can be made into microcapsules. This method has been used for decades. After the product is encapsulated by microcapsules, the stability of the product can be improved, and it can resist light, oxidation, and heat. The storage period of volatile products can be extended (such as flavor Substances and spices).
2.10 Use calcium chloride, chitosan and sodium alginate as the embedding wall material, and use Lab spray dryer to make the flour improver tea polyphenol into microcapsules. The results show that the best spray drying operating conditions are air flow rate of 750 L/h, inlet air temperature of 180°C, outlet air temperature of 100°C, composite wall material ratio of 2.5% sodium alginate and 0.8% chitosan , Calcium chloride is 4.5%, the mass ratio of core wall material is 2:1, and the maximum embedding rate is 73.8%.
2.11 During the preparation of onion oil essence microcapsules, the process method of complex agglomeration spray drying was optimized, and the Lab spray dryer was used to embed the onion oil essence twice to improve the stability of the product. The best operating conditions are that the ratio of maltodextrin and gum arabic is 1:1, the core material content is 25%, the material liquid concentration is 18%, the material liquid temperature is 50 ℃, the inlet air temperature is 180 ℃, and the outlet air temperature is 80 ℃. Application of Lab spray dryer can obtain powder microcapsules with excellent fluidity and dryness.
2.12 Use Lab spray dryer to prepare sesame oil microcapsules. The process parameters with the highest embedding rate obtained by rotating combination test are soybean protein isolate and gum arabic ratio 1:1, the core material content accounts for 25% of the solid content, the solid content fraction is 23%, the air inlet temperature is 180 ℃, and the air outlet The temperature is 80 ℃, the feed flow rate is 15 mL/min, and the material liquid temperature is 50 ℃. 2.13 Use Lab spray dryer to microencapsulate mustard oil. They used the rotating combination test to find that the optimal operating conditions are: the ratio of maltodextrin to gum arabic is 8:2, the ratio of wall material to core material is 3:1, the solid content is 35%, the feed rate is 15 r/min, and the inlet temperature 235 ℃, outlet temperature 90 ℃, under these conditions, 93.1% embedding rate can be obtained. At present, the method of preparing microcapsules using Lab spray dryer to extend the shelf life has been widely used.
2.14 Use Lab spray dryer to microencapsulate products such as squid liver oil, olive juice, and garlic oil.
3 Conclusion
Lab spray dryer are currently used in a wide range of applications, and their uses are becoming increasingly diverse. With the rapid development of society and technology, the Lab spray dryer should be supported and developed by more other new technologies (such as ultrasonic technology, microwave technology, etc.). This will not only achieve the effect of energy saving and environmental protection, but also better improve the quality of lab spray dryer, which will be the research direction for the improvement and upgrade of Lab spray dryer in the future.