Application of Chinese medicine extract in drying equipment (spray dryer)

The application of Chinese medicine extract in drying equipment (spray dryer) is to use heat to vaporize the liquid in wet material, to be carried away by drying medium, so that wet material can be dried There are two drying methods, one is natural drying, the other is artificial drying Among them, natural drying is to place the wet materials on the open or indoor site, and use the natural conditions of wind and sun to dehydrate and dry the materials; manual drying is to heat the wet materials in a special (dryer) to dry the materials Drying is an important link in the production of traditional Chinese medicine It is widely used in the production of pharmaceutical excipients, APIs, intermediates and finished products, especially in the drying of traditional Chinese medicine extracts Its operation directly affects the performance, quality, appearance and cost of products 1, at present, the drying of extract mainly depends on the traditional drying equipment such as hot air circulation oven and vacuum drying box In recent years, spray drying, vacuum freeze drying, microwave vacuum drying and other new drying technologies have been popularized in the drying process of Chinese medicine extract Due to the large viscosity and poor air permeability of traditional Chinese medicine extract, there are some disadvantages in the drying process of traditional Chinese medicine extract, such as long drying time, low output, high energy consumption, low production efficiency and low product quality, which can not meet the requirements of the modernization of traditional Chinese medicine, energy saving, environmental protection and advanced drying process of traditional Chinese medicine extract Using high and new technology to transform the traditional manufacturing mode of traditional Chinese medicine products has become the first key problem to be solved for the Chinese medicine industry to move towards high-tech industrialization Among them, the vacuum low-temperature continuous belt dryer can effectively solve the problem of traditional Chinese medicine extract drying, but due to the late start of this technology in China, especially in the traditional Chinese medicine industry, the lack of understanding of this technology limits its promotion and application Therefore, it is of great significance to speed up the promotion and application of the vacuum low temperature continuous belt dryer with energy conservation and environmental protection in the industry for improving the overall equipment level of Chinese medicine industry 2 The common drying technology of traditional Chinese medicine extract 2.1 vacuum drying oven vacuum drying oven is an earlier and simple drying method, which is still widely used in the drying of traditional Chinese medicine extract The vacuum drying box is composed of a pipe frame made of multi-layer heating plates or steam heating pipes Hot water or low-pressure steam is introduced into the heating plate or heating pipe frame as the heating medium The material tray for laying the medicine to be dried is placed on the heating plate or pipe frame, and the box is vacuumized by the vacuum pump The heating plate or the heating pipe rack heats the medicine to the specified temperature in the circulation flow of the heating medium, uses the vacuum pump to extract the air and wet to evaporate the moisture in the material, and with the vacuum pumping, the working room is in the vacuum state, the drying speed of the material is greatly accelerated, and the energy is saved at the same time The characteristics of vacuum drying oven are simple and easy to operate, less investment, strong applicability, and generally applicable to inflammable, sticky, thixotropic or paste materials During the drying process, the medicine is not easy to be polluted, so it can be used in medicine drying and heat treatment But there are also many defects, such as high labor intensity, large heat consumption, low thermal efficiency (thermal energy utilization rate is less than 40%), and long drying time, easy to produce some thermal sensitive components decomposition, unsightly color, drug quality reduction, at the same time, in the drying process, materials are easy to form hard blocks, hard to crush, poor taste Vacuum drying oven is suitable for drying small batch and various kinds of materials, so there are different sizes of drying equipment installed in laboratories, intermediate test plants and factories With the development of new technology, vacuum drying oven is gradually replaced by other drying technology At present, most of the vacuum drying boxes in traditional Chinese medicine enterprises are modified and imported equipment, which have higher heat transfer coefficient, better heat utilization rate and shorter drying time 2.2 spray drying technology has been widely applied in China's pharmaceutical industry In recent years, with the combination of fluidization, microencapsulation and coating technology, spray technology has been expanding and playing an increasingly important role in the field of traditional Chinese medicine During the spray drying process of Chinese medicine extract, the clean air of Grade 100 thousand is cleaned by primary and intermediate filtration, and heated to the required temperature by steam heat exchange and electric heating compensation After being evenly distributed, the hot air distributor is put into the tower At the same time, the material is supplied from the feed pump to the centrifugal atomizer at the top of the drying tower, and atomized into the corresponding droplet, and uniformly sprayed into the drying tower Hot air with good distribution, large area of convective contact, instantaneous completion of drying and forming, to obtain powder or granular products Spray drying has the characteristics of fast drying speed, stable product quality and high production efficiency At the same time, it can save concentration, filtration, grinding and other processes The fluidity and instant solubility of products are relatively good In the Chinese medicine and pharmaceutical industry, the application of spray drying technology greatly simplifies the process of extracting Chinese medicine to the semi-finished products or finished products, thereby shortening the production cycle and improving the production efficiency and product quality For the Chinese medicine extract, the major problem of spray drying Zui is that the sticky walls and drying products are easy to absorb moisture during the drying process, so it is difficult to handle high concentration and high viscosity Chinese medicine extract The research shows that the softening point of Chinese medicine extract is lower than that of spray drying, which is the main reason for sticking phenomenon By adding excipients to improve the softening point of the extract, the sticking phenomenon can be eliminated, but the addition of excipients may affect the purity of the product Another defect of spray drying is that the recovery rate of products is lower than that of drying technology 2.3 based on the mechanism of heat and mass transfer under low temperature and low pressure, freeze the extract of traditional Chinese medicine in a low temperature environment lower than the eutectic point temperature of the extract, and then place it in a high vacuum environment, so that the moisture in the material can be directly sublimed into gas in the state of ice crystal, so as to remove the moisture in the material Freeze drying is suitable for the drying of heat sensitive or oxidable drugs It is widely used in the drying process of traditional Chinese medicine Because of the low temperature operation, the freeze-drying process has a great advantage in maintaining the stability of the active ingredients of the extract The disadvantages of freeze-drying are complex equipment and high drying cost Therefore, the economy is the bottleneck of the application of freeze-drying technology in traditional Chinese medicine industry How to improve the productivity of freeze-drying equipment and reduce energy consumption is the key of freeze-drying technology research 2.4 the vacuum low temperature continuous belt dryer is a relatively moderate drying method between vacuum drying and spray drying in the aspect of drying temperature and efficiency Although the domestic development is not long, it is highly concerned by people in the industry and has been highly evaluated by users The vacuum low temperature continuous belt dryer is a kind of contact vacuum drying equipment with continuous feeding and continuous discharging After the traditional Chinese medicine extract is preheated to the set temperature in the feeding tank, it is fed by the feeding pump according to the preset feeding rate, and evenly spread on the dry strip drying belt in the dryer through the distributor The special rubber roller driven by the motor drives the drying belt to dry along the set speed The cylinder moves in the direction Each drying belt is equipped with an independent heating plate and a cooling plate The drying belt is closely connected with the heating plate and the cooling plate to transfer the energy needed for drying to the material in the way of contact heat transfer When the drying belt moves from one end of the cylinder to the other end, the material has dried and cooled When the drying belt is folded back, the dried material cake is peeled off from the drying belt, and it is knocked down into the crushing device through an up and down moving cutting device, and the crushed material is discharged through two air lock type discharge hoppers Due to the direct entry of the material into high vacuum, after a period of time and gradual drying (usually 30-60 min), the particles obtained after drying have micro pores in the internal structure After directly crushing to the required particle size, the fluidity of the particles is very good, which can be directly pressed or filled with capsules At the same time, due to the micro loose structure of the particles, the instant property is excellent, and the appearance of the particles is good, for the instant (powder) products, the product grade can be greatly improved The belt vacuum dryer can be set in the clean room for continuous feeding, continuous discharging, batching and discharging at both ends of the machine body The whole drying process is completely closed and does not contact with the external environment, which conforms to GMP Vacuum belt drying technology features: (1) low drying temperature, suitable for drying heat sensitive traditional Chinese medicine extract; (2) suitable for drying easily oxidized traditional Chinese medicine extract; (3) suitable for drying high concentration, high viscosity traditional Chinese medicine extract; (4) good solubility of the product, after drying, there are micro holes in the material from the microstructure, after directly crushing to the required particle size, the particle fluidity Very good, at the same time, due to the micro loose structure of particles, the instant solubility is excellent; (5) in the process of product drying, the product has been in a vacuum state, and the material is cooled to make it close to room temperature, reduce product oxidation and make the material not easy to paste Zui can keep its original color, fragrance and taste to a large extent, and get high-quality Zui end products; (6) it can be operated continuously and is suitable for large-scale production Vacuum low temperature continuous belt dryer is a new concept of energy-saving, environmental protection drying equipment It has been successfully applied to the drying of Salvia miltiorrhiza extract, Panax notoginseng extract, angelica extract, food gluten, coffee, milk powder and so on, and has achieved good results, especially for food, because of its short drying time, low temperature, no oxidation in vacuum state, it has the advantages of good retention of fragrance, which can also be applied in the pharmaceutical field, for some active substances, API, thermosensitive Sexual substances, vitamins, aromatic substances and so on have good retention of activity and fragrance 2.5 other drying methods in addition to the above drying technologies commonly used in the traditional Chinese medicine industry, there are many other drying equipment suitable for the drying of paste materials, such as microwave vacuum dryer, air flow dryer, fluidization dryer, rotary flash dryer, double cone rotary dryer, multi-functional dryer, etc However, these drying equipment is not specially used for the drying of traditional Chinese medicine extracts Due to the high viscosity, high sugar content and poor permeability of traditional Chinese medicine extracts, it is necessary to improve these drying equipment in order to be used in the traditional Chinese medicine industry Although there are many kinds of drying methods and equipment suitable for Chinese medicine extract, spray drying, vacuum belt drying and freeze-drying are the most commonly used technologies at present These technologies have their advantages and application scope According to the characteristics of Chinese medicine, reasonable selection of drying methods is conducive to improving the quality of Chinese Medicine extract and reducing the production cost 3 The way to improve drying efficiency in order to improve the quality of traditional Chinese medicine extract and reduce the loss of effective components of the extract, on the one hand, it is necessary to choose a reasonable drying process, on the other hand, it is necessary to constantly change the drying equipment to improve the drying efficiency Attention should be paid to the following aspects: (1) improve the drying process of existing equipment; (2) adopt new drying methods and combined drying methods to overcome the defects of single technology; (3) as drying is a unit process with large energy consumption in the production of traditional Chinese medicine, how to save energy and meet the environmental requirements should be considered in the design and operation Conclusion: with the continuous development of science and technology, the drying equipment technology of traditional Chinese medicine industry is also constantly improving, and new drying technologies emerge in endlessly, which will certainly accelerate the process of modernization of traditional Chinese medicine in China.